U.S. patent application number 10/719441 was filed with the patent office on 2005-08-25 for ni catalysts and methods for alkane dehydrogenation.
This patent application is currently assigned to Symyx Technologies, Inc.. Invention is credited to Liu, Yumin.
Application Number | 20050187420 10/719441 |
Document ID | / |
Family ID | 26944654 |
Filed Date | 2005-08-25 |
United States Patent
Application |
20050187420 |
Kind Code |
A9 |
Liu, Yumin |
August 25, 2005 |
Ni catalysts and methods for alkane dehydrogenation
Abstract
Catalysts and methods for alkane oxydehydrogenation are
disclosed. The catalysts of the invention generally comprise (i)
nickel or a nickel-containing compound and (ii) at least one or
more of titanium (Ti), tantalum (Ta), niobium (Nb), hafnium (Hf),
tungsten (W), yttrium (Y), zinc (Zn), zirconium (Zr), or aluminum
(Al), or a compound containing one or more of such element(s). In
preferred embodiments, the catalyst is a supported catalyst, the
alkane is selected from the group consisting of ethane, propane,
isobutane, n-butane and ethyl chloride, molecular oxygen is co-fed
with the alkane to a reaction zone maintained at a temperature
ranging from about 250.degree. C. to about 350.degree. C., and the
ethane is oxidatively dehydrogenated to form the corresponding
alkene with an alkane conversion of at least about 10% and an
alkene selectivity of at least about 70%.
Inventors: |
Liu, Yumin; (San Jose,
CA) |
Correspondence
Address: |
FISH & NEAVE IP GROUP
ROPES & GRAY LLP
1251 AVENUE OF THE AMERICAS FL C3
NEW YORK
NY
10020-1105
US
|
Assignee: |
Symyx Technologies, Inc.
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 0090702 A1 |
April 28, 2005 |
|
|
Family ID: |
26944654 |
Appl. No.: |
10/719441 |
Filed: |
November 20, 2003 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10719441 |
Nov 20, 2003 |
|
|
|
09849378 |
May 4, 2001 |
|
|
|
6777371 |
|
|
|
|
09849378 |
May 4, 2001 |
|
|
|
09510458 |
Feb 22, 2000 |
|
|
|
6417422 |
|
|
|
|
09510458 |
Feb 22, 2000 |
|
|
|
09255371 |
Feb 22, 1999 |
|
|
|
6355854 |
|
|
|
|
09510458 |
Feb 22, 2000 |
|
|
|
09255384 |
Feb 22, 1999 |
|
|
|
6436871 |
|
|
|
|
Current U.S.
Class: |
585/660 ;
502/302; 502/328 |
Current CPC
Class: |
C07C 2523/20 20130101;
B01J 23/8476 20130101; C07C 45/35 20130101; C07C 45/35 20130101;
C07C 51/25 20130101; C07C 45/34 20130101; C07C 2523/10 20130101;
C07C 51/25 20130101; C07C 45/34 20130101; B01J 23/83 20130101; C07C
5/48 20130101; C07C 45/33 20130101; C07C 5/48 20130101; B01J 23/80
20130101; C07C 45/34 20130101; C07C 45/33 20130101; C07C 2521/04
20130101; C07C 47/21 20130101; C07C 11/02 20130101; C07C 49/10
20130101; C07C 47/22 20130101; C07C 47/22 20130101; C07C 49/205
20130101; C07C 53/08 20130101; C07C 49/08 20130101; C07C 45/34
20130101; C07C 2523/755 20130101; B01J 23/76 20130101; C07C 2523/30
20130101; C07C 2521/06 20130101; C07C 45/34 20130101; C07C 2523/75
20130101; B01J 23/8474 20130101; C07C 2523/06 20130101 |
Class at
Publication: |
585/660 ;
502/302; 502/328 |
International
Class: |
C07C 005/333; B01J
023/00; B01J 023/58 |
Claims
1-107. (canceled)
108. A method for preparing a catalyst, the method comprising
forming a pre-calcination composition by a method that includes
combining a Ni-component with a first minor component, and
optionally with second and third minor components, the Ni-component
consisting essentially of Ni, a Ni oxide, a Ni salt, or mixtures
thereof, the mole fraction of the Ni-component ranging from about
0.5 to about 0.96, the first minor component consisting essentially
of an element or compound comprising a member from the group
consisting of Ti, Ta, Nb, Co, Hf, Y, Zn, Zr, Al, oxides thereof,
salts thereof, and mixtures thereof, the mole fraction of the first
minor component ranging from about 0.04 to about 0.5, the second
minor component consisting essentially of an element or compound
comprising a member selected from the group consisting of a
lanthanide element, a group IIIA element, a group VA element, a
group VIA element, a group III element, a group IVB element, a
group VB element, a group VIB element, oxides thereof, salts
thereof, and mixtures thereof, the mole fraction of the second
minor component ranging from 0 to about 0.4, the third minor
component consisting essentially of an element or compound
comprising a member selected from the group consisting of an alkali
metal, an alkaline earth metal, oxides thereof, salts thereof, and
mixtures thereof, the mole fraction of the third minor component
ranging from 0 to about 0.4, and calcining the pre-calcination
composition.
109. A method for preparing a C.sub.2 to C.sub.4 alkene or a
substituted C.sub.2 to C.sub.4 alkene from the corresponding
C.sub.2 to C.sub.4 alkane or substituted C.sub.2 to C.sub.4 alkane,
the method comprising providing a C.sub.2 to C.sub.4 alkane or a
substituted C.sub.2 to C.sub.4 alkane and a gaseous oxidant to a
reaction zone containing a catalyst, the catalyst comprising Ni, a
Ni oxide, a Ni salt or mixtures thereof, maintaining the reaction
zone at a temperature ranging from about 200.degree. C. to about
350.degree. C., and oxidatively dehydrogenating the C.sub.2 to
C.sub.4 alkane or substituted C.sub.2 to C.sub.4 alkane to form the
corresponding C.sub.2 to C.sub.4 alkene or substituted C.sub.2 to
C.sub.4 alkene in the reaction zone under reaction conditions
effective to convert the C.sub.2 to C.sub.4 alkane or substituted
C.sub.2 to C.sub.4 alkane to the C.sub.2 to C.sub.4 alkene or
substituted C.sub.2 to C.sub.4 alkene, the reaction zone comprising
the corresponding C.sub.2 to C.sub.4 alkene or substituted C.sub.2
to C.sub.4 alkene in a molar concentration of at least about 5%,
relative to total moles of hydrocarbon, during the
oxydehydrogenation, the C.sub.2 to C.sub.4 alkane or substituted
C.sub.2 to C.sub.4 alkane conversion being at least about 5%, and
the C.sub.2 to C.sub.4 alkene or substituted C.sub.2 to C.sub.4
alkane selectivity being at least about 50%.
110. The method of claim 109 wherein the C.sub.2 to C.sub.4 alkane
or substituted C.sub.2 to C.sub.4 alkane and the gaseous oxidant
are co-fed to the reaction zone, the method further comprising
co-feeding a C.sub.2 to C.sub.4 alkene or substituted C.sub.2 to
C.sub.4 alkene corresponding to the C.sub.2 to C.sub.4 alkane or
substituted C.sub.2 to C.sub.4 alkane to the reaction zone.
111. The method of claim 109 wherein the C.sub.2 to C.sub.4 alkane
or substituted C.sub.2 to C.sub.4 alkane and the gaseous oxidant
are co-fed to the reaction zone, the method further comprising
exhausting a product stream comprising the corresponding C.sub.2 to
C.sub.4 alkene or substituted C.sub.2 to C.sub.4 alkene and
unreacted C.sub.2 to C.sub.4 alkane or substituted C.sub.2 to
C.sub.4 alkane from the reaction zone, and recycling at least a
portion of the C.sub.2 to C.sub.4 alkene or substituted C.sub.2 to
C.sub.4 alkene and unreacted C.sub.2 to C.sub.4 alkane or
substituted C.sub.2 to C.sub.4 alkane containing product stream to
the reaction zone.
112. A method for preparing a C.sub.2 to C.sub.4 alkene or a
substituted C.sub.2 to C.sub.4 alkane from the corresponding
C.sub.2 to C.sub.4 alkane or substituted C.sub.2 to C.sub.4 alkane
the method comprising feeding a C.sub.2 to C.sub.4 alkane or
substituted C.sub.2 to C.sub.4 alkane to a first reaction zone
containing a catalyst, the catalyst comprising a calcination
product of a composition comprising (i) Ni, a Ni oxide, a Ni salt
or mixtures thereof, and (ii) an element or compound selected from
the group consisting of Ti, Ta, Nb, Co, Hf, W, Y, Zn, Zr, Al,
oxides thereof and salts thereof, or mixtures of such elements or
compounds, co-feeding a gaseous oxidant to the first reaction zone,
dehydrogenating the C.sub.2 to C.sub.4 alkane or substituted
C.sub.2 to C.sub.4 alkane to form the corresponding C.sub.2 to
C.sub.4 alkene or substituted C.sub.2 to C.sub.4 alkene in the
first reaction zone under reaction conditions effective to convert
the C.sub.2 to C.sub.4 alkane or substituted C.sub.2 to C.sub.4
alkane to the C.sub.2 to C.sub.4 alkene or substituted C.sub.2 to
C.sub.4 alkene, exhausting a product stream comprising the
corresponding C.sub.2 to C.sub.4 alkene or substituted C.sub.2 to
C.sub.4 alkene and unreacted C.sub.2 to C.sub.4 alkane or
substituted C.sub.2 to C.sub.4 alkane from the first reaction zone
containing the catalyst, feeding the C.sub.2 to C.sub.4 alkene or
substituted C.sub.2 to C.sub.4 alkene and unreacted C.sub.2 to
C.sub.4 alkane or substituted C.sub.2 to C.sub.4 alkane containing
product stream from the first reaction zone to a second reaction
zone, co-feeding a gaseous oxidant to the second reaction zone,
dehydrogenating the C.sub.2 to C.sub.4 alkane or substituted
C.sub.2 to C.sub.4 alkane to form the corresponding C.sub.2 to
C.sub.4 alkane or substituted C.sub.2 to C.sub.4 alkane in the
second reaction zone.
113. The method of claim 112, wherein the concentration of oxygen
in the first and second reaction zones is controlled to obtain an
overall C.sub.2 to C.sub.4 alkane or substituted C.sub.2 to C.sub.4
alkane conversion of at least about 5% and an overall C.sub.2 to
C.sub.4 alkene or substituted C.sub.2 to C.sub.4 alkene selectivity
of at least about 50%.
114. The method of claim 112 wherein the molar concentration of
oxygen in the first and second reaction zones ranges from about 3%
to about 20%, in each case relative to ethane.
115. The method of claim 112 wherein the second reaction zone
comprises the corresponding C.sub.2 to C.sub.4 alkene or
substituted C.sub.2 to C.sub.4 alkene at a molar concentration of
at least about 5%, relative to total moles of hydrocarbon.
116. The method of claim 112 wherein the C.sub.2 to C.sub.4 alkane
or substituted C.sub.2 to C.sub.4 alkane is oxidatively
dehydrogenated in the second reaction zone to form the
corresponding C.sub.2 to C.sub.4 alkene or substituted C.sub.2 to
C.sub.4 alkene with a C.sub.2 to C.sub.4 alkane or substituted
C.sub.2 to C.sub.4 alkane conversion of at least about 5% and a
C.sub.2 to C.sub.4 alkene or substituted C.sub.2 to C.sub.4 alkene
selectivity of at least about 50%.
117. A method for preparing acetic acid from substituted or
unsubstituted ethane, the method comprising providing substituted
or unsubstituted ethane and a gaseous oxidant to a reaction zone
containing a catalyst and a co-catalyst, the catalyst comprising
Ni, a Ni oxide, a Ni salt, or mixtures thereof and one or more
components consisting essentially of Ti, Ta, Nb, Co, Hf, W, Zn, Zr,
Al, oxides thereof and salts thereof, or mixtures thereof, and the
co-catalyst having activity to oxidize ethylene to acetic acid, and
dehydrogenating the substituted or unsubstituted ethane to form
substituted or unsubstituted ethylene; and oxidizing the
unsubstituted or substituted ethylene to form substituted or
unsubstituted acetic acid.
118. The method of claim 117 further comprising providing an
integrated catalyst composition comprising the catalyst and
co-catalyst to the reaction zone.
119. The method of claim 117 further comprising providing a single
composition comprising the catalyst and co-catalyst to the reaction
zone, wherein the catalyst and the co-catalyst are in separate
phases.
120. A method for preparing vinyl chloride from substituted or
unsubstituted ethane, the method comprising providing substituted
or unsubstituted ethane and a gaseous oxidant to a reaction zone
containing a catalyst and a co-catalyst, the catalyst comprising
Ni, a Ni oxide, a Ni salt, or mixtures thereof and one or more
components consisting essentially of Ti, Ta, Nb, Co, Hf, W, Zn, Zr,
Al, oxides thereof and salts thereof, or mixtures thereof, and the
co-catalyst having activity to chlorinate or oxychlorinate ethylene
to vinyl chloride, and dehydrogenating the substituted or
unsubstituted ethane to form substituted or unsubstituted ethylene;
and chlorinating or oxychlorinating the unsubstituted or
substituted ethylene to form substituted or unsubstituted vinyl
chloride.
121. The method of claim 120 further comprising providing an
integrated catalyst composition comprising the catalyst and
co-catalyst to the reaction zone.
122. The method of claim 120 further comprising providing a single
composition comprising the catalyst and co-catalyst to the reaction
zone, wherein the catalyst and the co-catalyst are in separate
phases.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention generally relates to catalysts and
methods for alkane or alkene dehydrogenation and specifically, to
Ni-containing catalysts and methods for oxidative dehydrogenation
of alkanes or alkenes. The invention particularly relates, in
preferred embodiments, to Ni oxide/mixed-metal oxide catalysts and
methods for oxidative dehydrogenation of alkanes or alkenes, and
especially of C.sub.2 to C.sub.4 alkanes, and particularly, for
oxidative dehydrogenation of ethane to ethylene.
[0002] Ethylene can be produced by thermal cracking of
hydrocarbons, by non-oxidative dehydrogenation of ethane, or by
oxidative dehydrogenation of ethane (ODHE). The latter process is
attractive for many reasons. For example, compared to thermal
cracking, high ethane conversion can be achieved at relatively low
temperatures (about 400.degree. C. or below). Unlike thermal
cracking, catalytic ODHE is exothermic, requiring no additional
heat to sustain the reaction. In contrast to catalytic
non-oxidative dehydrogenation, catalyst deactivation by coke
formation is relatively minimal in ODHE because of the presence of
oxidant (e.g., molecular oxygen) in the reactor feed. Other alkanes
can be similarly oxidatively dehydrogenated to the corresponding
alkene.
[0003] Thorsteinson and coworkers have disclosed useful
low-temperature ODHE catalysts comprising mixed oxides of
molybdenum, vanadium, and a third transition metal. E. M
Thorsteinson et al., "The Oxidative Dehydrogenation of Ethane over
Catalyst Containing Mixed Oxide of Molybdenum and Vanadium," 52 J.
Catalysis 116-32 (1978). More recent studies examined families of
alumina-supported vanadium-containing oxide catalysts, MV and MVSb,
where M is Ni, Co, Bi, and Sn. R. Juarez Lopez et al., "Oxidative
Dehydrogenation of Ethane on Supported Vanadium-Containing Oxides,"
124 Applied Catalysis A: General 281-96 (1995). Baharadwaj et al.
disclose oxidative dehydrogenation of ethane and other alkanes
using a catalysts of Pt, Rh, Ni or Pt/Au supported on alumina or
zirconia. See PCT Patent Application WO 96/33149. U.S. Pat. No.
5,439,859 to Durante et al. discloses the use of reduced, sulfided
nickel crystallites on siliceous supports for dehydrogenation and
successive oxidation of alkanes. Schuurman and coworkers describe
unsupported iron, cobalt and nickel oxide catalysts that are active
in ODHE. Y. Schuurman et al., "Low Temperature Oxidative
Dehydrogenation of Ethane over Catalysts Based on Group VIII
Metals," 163 Applied Catalysis A: General 227-35 (1997). Other
investigators have also considered the use of nickel or nickel
oxide as catalysts or catalyst components for oxidative
dehydrogenation. See, for example, Ducarme et al., "Low Temperature
Oxidative Dehydrogenation of Ethane over Ni-based Catalysts", 23
Catalysis Letters 97-101 (1994); U.S. Pat. No. 3,670,044 to Drehman
et al.; U.S. Pat. No. 4,613,715 to Haskell; U.S. Pat. No. 5,723,707
to Heyse et al.; U.S. Pat. No. 5,376,613 to Dellinger et al.; U.S.
Pat. No. 4,070,413 to Imai et al.; U.S. Pat. No. 4,250,346 to Young
et al.; and U.S. Pat. No. 5,162,578 to McCain et al.
[0004] Although nickel-containing catalysts are known in the art
for alkane dehydrogenation reactions, none of the known
nickel-containing catalysts have been particularly attractive for
commercial applications--primarily due to relatively low conversion
and/or selectivity. Hence, a need exists for new, industrially
suitable catalysts and methods having improved performance
characteristics (e.g., conversion and selectivity) for the
oxidative dehydrogenation of alkanes.
SUMMARY OF INVENTION
[0005] It is therefore an object of the present invention to
provide for new, industrially suitable catalysts for oxidative
dehydrogenation of alkanes to the corresponding alkenes.
[0006] Briefly, therefore, the invention is directed to methods for
preparing an alkene, and preferably a C.sub.2 to C.sub.4 alkene,
such as ethylene, from the corresponding alkane, such as ethane. In
general, the method comprises providing the alkane (or substituted
alkane), and preferably the C.sub.2 to C.sub.4 alkane (or
substituted C.sub.2 to C.sub.4 alkane) and an oxidant to a reaction
zone containing a catalyst, and dehydrogenating the alkane to form
the corresponding alkene. The oxidant is preferably a gaseous
oxidant such as molecular oxygen, and is preferably provided, for
example, as oxygen gas, air, diluted air or enriched air. The
alkane is preferably oxidatively dehydrogenated. The reaction
temperature is preferably controlled, during the dehydrogenation
reaction, to be less than about 325.degree. C., and preferably less
than about 300.degree. C.
[0007] The catalyst comprises, in one embodiment, (i) a major
component consisting essentially of Ni, a Ni oxide, a Ni salt, or
mixtures thereof, and (ii) one or more minor components consisting
essentially of an element or compound selected from the group
consisting of Ti, Ta, Nb, Co, Hf, W, Y, Zn, Zr, Al, oxides thereof
and salts thereof, or mixtures of such elements or compounds. The
catalyst preferably comprises Ni oxide and one or more of Ti oxide,
Nb oxide, Ta oxide, Co oxide or Zr oxide.
[0008] In another embodiment, the catalyst comprises a compound
having the formula I,
Ni.sub.xA.sub.aB.sub.bC.sub.cO.sub.d (I), where
[0009] A is an element selected from the group consisting of Ti,
Ta, Nb, Hf, W, Y, Zn, Zr, Al, and mixtures of two or more thereof,
B is an element selected from the group consisting of a lanthanide
element, a group IIIA element, a group VA element, a group VIA
element, a group IIIB element, a group IVB element, a group VB
element, a group VIB element, and mixtures of two or more thereof,
C is an alkali metal, an alkaline earth metal or mixtures thereof,
x is a number ranging from about 0.1 to about 0.96, a is a number
ranging from about 0.04 to about 0.8, b is a number ranging from 0
to about 0.5, c is a number ranging from 0 to about 0.5, and d is a
number that satisfies valence requirements.
[0010] In a further embodiment, the catalyst comprises a compound
having the formula (I)
Ni.sub.xTi.sub.jTa.sub.kNb.sub.lLa*Sb.sub.rSn.sub.sBi.sub.lCa.sub.uK.sub.v-
Mg.sub.wO.sub.d (II), where
[0011] La* is one or more lanthanide series elements selected from
the group consisting of La.sub.m, Ce.sub.n, Pr.sub.o, Nd.sub.p,
Sm.sub.q, x is a number ranging from about 0.1 to about 0.96, j, k
and 1 are each numbers ranging from 0 to about 0.8 and the sum of
(j+k+1) is at least about 0.04, m, n, o, p, q, r, s and t are each
numbers ranging from 0 to about 0.1, and the sum of
(m+n+o+p+q+r+s+t) is at least about 0.005, u, v and w are each
numbers ranging from 0 to about 0.1, and d is a number that
satisfies valence requirements.
[0012] In still another embodiment, the catalyst comprises (i) a Ni
oxide, and (ii) an oxide of an element selected from the group
consisting of Ti, Ta, Nb, Co, Hf, W, Y, Zn, Zr, and Al, and the
alkane is dehydrogenated to form the corresponding alkene with an
alkane conversion of at least about 10% and an alkene selectivity
of at least about 70%. Ethane conversion is preferably at least
about 15% and more preferably at least about 20%. Ethylene
selectivity is, in combination with any of the preferred conversion
values, preferably at least about 80%, and more preferably at least
about 90%.
[0013] In one embodiment, the catalyst is a calcination product of
a catalyst precursor composition comprising (i) Ni, a Ni oxide, a
Ni salt or mixtures thereof, and (ii) an element or compound
selected from the group consisting of Ti, Ta, Nb, Co, Hf, W, Y, Zn,
Zr, Al, oxides thereof and salts thereof, or mixtures of such
elements or compounds.
[0014] In yet another embodiment, the alkane is co-fed to a
reaction zone with the corresponding alkene, such that the alkane
is dehydrogenated to form the alkene in a reaction zone comprising
the corresponding alkene in a molar concentration of at least about
5%, relative to total moles of hydrocarbon. The alkane conversion
in such embodiment is preferably at least about 5%, and the alkene
selectivity is preferably at least about 50%. In a preferred
approach, the alkane dehydrogenation is effected in a multi-stage
reactor, such that the alkane (or substituted C.sub.2 to C.sub.4
alkane) and gaseous oxidant are fed to a first reaction zone
containing the catalyst, the alkane is dehydrogenated therein to
form the corresponding alkene, the product stream comprising the
corresponding alkene and unreacted alkane are exhausted from the
first reaction zone and then fed to a second reaction zone,
together with additional, supplemental gaseous oxidant, and the
alkane is dehydrogenated to form the corresponding alkene in the
second reaction zone.
[0015] The invention also directed to nickel-containing mixed-metal
oxide compositions and catalysts, as characterized above, and to
methods for preparing the same.
[0016] Such catalysts and methods have advantageous performance
characteristics for oxidative dehydrogenation of alkanes to their
corresponding alkene, and particularly for dehydrogenation of
unsubstituted or substituted C.sub.2 to C.sub.4 alkanes to the
corresponding alkene(s). The conversion, selectivity, space
velocity, catalyst stability and reaction temperature for
oxydehydrogenation of ethane to ethylene are particularly
attractive.
[0017] Other features, objects and advantages of the present
invention will be in part apparent to those skilled in art and in
part pointed out hereinafter. All references cited in the instant
specification are incorporated by reference for all purposes.
Moreover, as the patent and non-patent literature relating to the
subject matter disclosed and/or claimed herein is substantial, many
relevant references are available to a skilled artisan that will
provide further instruction with respect to such subject
matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1A and FIG. 1B are schematic representations of
exemplary reaction system configurations, specifically involving
product stream recycle (FIG. 1A) and multi-stage reaction zones
(FIG. 1B).
[0019] FIG. 2A and FIG. 2B are graphs showing ethane conversion
(open circles) and ethylene selectivity (closed circles) data
versus time on stream during the 400 hour lifetime test in the
parallel fixed bed reactor at 275.degree. C. for
Ni.sub.0.75Ta.sub.0.28Sn.sub.0.03O.sub.x (FIG. 2A) and
Ni.sub.0.71Nb.sub.0.27Co.sub.0.02O.sub.x (FIG. 2B).
DETAILED DESCRIPTION OF THE INVENTION
[0020] According to the present invention, an alkane or alkene is
oxidatively dehydrogenated over a nickel catalyst to form one or
more corresponding alkene(s) or dialkene, respectively, and water.
The oxidative dehydrogenation reaction can be represented (for
alkane reactants) as:
C.sub.nH.sub.2n+2+1/2O.sub.2.fwdarw.C.sub.nH.sub.2n+H.sub.2O
[0021] The catalysts of the invention generally comprise (i) nickel
or a nickel-containing compound and (ii) at least one or more of
titanium (Ti), tantalum (Ta), niobium (Nb), cobalt (Co), hafnium
(Hf), tungsten (V), yttrium (Y), zinc (Zn), zirconium (Zr), or
aluminum (Al), or a compound containing one or more of such
element(s).
[0022] In one embodiment of the invention, the nickel catalyst
comprises (i) Ni, a Ni oxide, a Ni salt, or mixtures thereof as a
major component, and (ii) an element or compound selected from the
group consisting of Ti, Ta, Nb, Co, Hf, W, Y, Zn, Zr, Al, oxides
thereof and salts thereof, or mixtures of such elements or
compounds as one or more minor components. As used herein, the
"major component" is the component of the catalytically active
compound or composition having the highest concentration on an
atomic basis. "Minor components" are components of the
catalytically active compound or composition that do not have the
highest concentration on an atomic basis. In general, one of the
aforementioned metal components may be present as in elemental
form, as an oxide, and/or as a salt depending on the nature and
extent of calcination.
[0023] The major component of the catalyst preferably consists
essentially of a Ni oxide. The major component of the catalyst can,
however, also include various amounts of elemental Ni and/or
Ni-containing compounds, such as Ni salts. The Ni oxide is an oxide
of nickel where nickel is in an oxidation state other than the
fully-reduced, elemental Ni.degree. state, including oxides of
nickel where nickel has an oxidation state of Ni.sup.+2, Ni.sup.+3,
or a partially reduced oxidation state. The Ni salts can include
any stable salt of nickel, including, for example, nitrates,
carbonates and acetates, among others. The amount of nickel oxide
(NiO) present in the major component is at least about 10%,
preferably at least about 20%, more preferably at least about 35%,
more preferably yet at least about 50% and most preferable at least
about 60%, in each case by moles relative to total moles of the
major component. Without being bound by theory not specifically
recited in the claims, the Ni and/or Ni oxide acts as a
redox-active metal center for the oxydehydrogenation reaction.
[0024] The one or more minor component(s) of the catalyst
preferably consist essentially of an element or compound selected
from the group consisting of Ti, Ta, Nb, Co, Hf, W, Y, Zn, Zr, Al,
oxides thereof and salts thereof, or mixtures of such elements or
compounds. The minor component(s) more preferably consist
essentially of one or more of the following groupings of elements,
oxides thereof, salts thereof, or mixtures of the same: (i) Ti, Ta,
Nb, Hf, W, Y, Zn, Zr, Al, (ii) Ti, Ta, Nb, Hf, W and Y; (iii) Ti,
Ta, Nb, Hf and W; (iv) Ti, Ta, Nb, Co and Zr (v) Ti, Ta, Nb and Co,
(vi) Ti, Ta, Nb and Zr, and (vii) Ti, Ta and Nb. The minor
component can likewise consist essentially of each of the
aforementioned minor-component elements (Ti, Ta, Nb, Co Hf, W, Y,
Zn, Zr or Al) individually, oxides thereof, salts thereof, or
mixtures of the same. With respect to each of the aforementioned
groupings of elements or individual elements, the minor
component(s) preferably consist essentially of oxides of one or
more of the minor-component elements, but can, however, also
include various amounts of such elements and/or other compounds
(e.g., salts) containing such elements. An oxide of such
minor-component elements is an oxide thereof where the respective
element is in an oxidation state other than the fully-reduced
state, and includes oxides having an oxidation states corresponding
to known stable valence numbers, as well as to oxides in partially
reduced oxidation states. Salts of such minor-component elements
can be any stable salt thereof, including, for example, nitrates,
carbonates and acetates, among others. The amount of the oxide form
of the particular recited elements present in one or more of the
minor component(s) is at least about 5%, preferably at least about
10%, preferably still at least about 20%, more preferably at least
about 35%, more preferably yet at least about 50% and most
preferable at least about 60%, in each case by moles relative to
total moles of the particular minor component. Without being bound
by theory not specifically recited in the claims, the one or more
first minor components provide a matrix environment for the Ni/Ni
oxide active metal center and help maintain the active metal center
well dispersed. Although the first minor components can themselves
be redox inactive under reaction conditions, particularly to oxygen
and hydrocarbons, they are nonetheless considered to be a component
of the catalytically active compound or composition. As noted
below, the first minor component can also have a support or carrier
functionality.
[0025] In another, preferred embodiment, the nickel catalyst can
comprise (i) a major component consisting essentially of Ni oxide;
and (ii) a minor component consisting essentially of one or more of
the following oxides, considered individually or collectively in
the various permutations: Ti oxide, Ta oxide, and/or Nb oxide,
optionally together with one or more of Hf oxide, W oxide, and/or Y
oxide, optionally together with one or more of Zn oxide, Zr oxide
and/or Al oxide.
[0026] In addition to the aforementioned minor component(s) of the
catalyst (generally referred to hereinafter as "first minor
components"), the catalyst can additionally comprise one or more
second minor components. The second minor component(s) can consist
essentially of an element or compound selected from the group
consisting of a lanthanide element, a group IIIA element, a group
VA element, a group VIA element, a group IIIB element, a group IVB
element, a group VB element, a group VIB element, oxides thereof
and salts thereof, or mixtures of such elements or compounds. The
second minor component preferably consists essentially of an
element or compound selected from the group consisting of La, Ce,
Pr, Nd, Sm, Sb, Sn, Bi, Pb, Tl, In, Te, Cr, V, Mn, Mo, Fe, Co, Cu,
Ru, Rh, Pd, Pt, Ag, Cd, Os, Re, Ir, Au, Hg, oxides thereof and
salts thereof, or mixtures of such elements or compounds. More
preferably, the second minor component consists essentially of an
element or compound selected from the group consisting of La, Ce,
Pr, Nd, Sm, Sb, Sn, Bi, Co, Ag, Cr, oxides thereof and salts
thereof, or mixtures of such elements or compounds. If Co is
considered within the group of first minor components, it can be
excluded from the aforementioned groups of second minor components.
The second minor component is preferably an oxide of one of the
aforementioned second-minor-component elements. The oxides and
salts can be as described above in connection with the first-minor
components. Without being bound by theory not specifically recited
in the claims, the second minor component can be redox active
components with respect to enhancing the redox potential of the
Ni/Ni oxide active metal centers.
[0027] The catalyst can also include, as yet a further (third)
minor component(s), one or more of an element or compound selected
from the group consisting of the alkali metals, the alkaline earth
metals, oxides thereof, and salts thereof, or mixtures of such
elements or compounds. Preferably, the third minor component
consists essentially of an element or compound selected from the
group consisting of Ca, K, Mg, Sr, Ba, Li and Na, most preferably
Ca, K and Mg, and in either case, oxides thereof and salts thereof,
or mixtures of such elements or compounds. The third minor
component is preferably an oxide of one of the aforementioned
third-minor-component elements. The oxides and salts can be as
described above in connection with the first-minor components.
Without being bound by theory not specifically recited in the
claims, the third minor components are preferably basic metal
oxides, and as such, can be employed to optimize the acidity or
basicity, in particular with respect to selectivity.
[0028] The catalyst can include other components as well, and can
be part of a composition that includes other components or agents
(e.g., diluents, binders and/or fillers, as discussed below) as
desired in connection with the reaction system of interest.
[0029] In a further embodiment, the nickel catalyst of the
invention can be a material comprising a mixed-metal oxide compound
having the formula (I):
Ni.sub.xA.sub.aB.sub.bC.sub.cO.sub.d (I),
[0030] where, A, B, C, x, a, b, c and d are described below, and
can be grouped in any of the various combinations and permutations
of preferences, some of which are specifically set forth
herein.
[0031] In formula I, "x" represents a number ranging from about 0.1
to about 0.96. The number x preferably ranges from about 0.3 to
about 0.85, more preferably from about 0.5 to about 0.9, and even
more preferably from about 0.6 to about 0.8.
[0032] In formula I, "A" represents an element selected from the
group consisting of Ti, Ta, Nb, Hf, W, Y, Zn, Zr and Al, or
mixtures of two or more thereof. A is preferably Ti, Ta, Nb, Hf, W
or Y, even more preferably Ti, Ta, Nb, Hf or W, and still more
preferably Ti, Ta or Nb, or, in each case, mixtures thereof. The
letter "a" represents a number ranging from about 0.04 to about
0.9, preferably from about 0.04 to about 0.8, more preferably from
about 0.04 to about 0.5, even more preferably from about 0.1 to
about 0.5, still more preferably from about 0.15 to about 0.5 and
most preferably from about 0.3 to about 0.4.
[0033] In formula I, "B" represents an element selected from the
group consisting of a lanthanide element, a group IIIA element,
element, a group VA element, a group VIA element, a group VIIA
element, a group VIIIA element, a group IB element, a group IIB
element, a group IIIB element, a group IVB element, a group VB
element, a group VIB element, and mixtures of two or more thereof.
As used herein, periodic table subgroup designations are those
recommended by the International Union of Pure and Applied
Chemistry (IUPAC), such as shown on the Periodic Table of the
Elements, Learning Laboratories, Inc. (1996). B is preferably an
element selected from the group consisting of La, Ce, Pr, Nd, Sm,
Sb, Sn, Bi, Pb, Tl, In, Te, Cr, V, Mn, Mo, Fe, Co, Cu, Ru, Rh, Pd,
Pt, Ag, Cd, Os, Re, Ir, Au, and Hg. B is more preferably an element
selected from the group consisting of La, Ce, Pr, Nd, Sm, Sb, Sn,
Bi, Co, Cr and Ag. The letter "b" represents a number ranging from
0 to about 0.5, more preferably from 0 to about 0.4, even more
preferably from 0 to about 0.2, still more preferably from 0 to
about 0.1, and most preferably from 0 to about 0.05.
[0034] In formula I, C is an alkali metal, an alkaline earth metal
or mixtures thereof . C is preferably an element selected from the
group consisting of Ca, K, Mg, Li, Na, Sr, Ba, Cs and Rb, and is
more preferably an element selected from the group consisting of
Ca, K and Mg. The letter "c" represents a number ranging from 0 to
about 0.5, more preferably from 0 to about 0.4, even more
preferably from 0 to about 0.1, and most preferably from 0 to about
0.05.
[0035] In formula I, "O" represents oxygen, and "d" represents a
number that satisfies valence requirements. In general, "d" is
based on the oxidation states and the relative atomic fractions of
the various metal atoms of the compound of formula I (e.g.,
calculated as one-half of the sum of the products of oxidation
state and atomic fraction for each of the metal oxide
components).
[0036] In one preferred mixed-metal oxide embodiment, where, with
reference to formula I, "b" and "c" are each zero, the catalyst
material can comprise a compound having the formula I-A:
Ni.sub.xA.sub.aO.sub.d (I-A),
[0037] where Ni is nickel, O is oxygen, and where "x", "A", "a" and
"d" are as defined above.
[0038] In another preferred mixed-metal oxide embodiment, with
reference to formula I, the sum of (a+b+c) is preferably less than
or not more than about 0.9, is preferably not more than about 0.7,
and is even more preferably not more than about 0.5, and moreover,
this sum preferably ranges from about 0.04 to about 0.6, more
preferably from about 0.1 to about 0.5 and most preferably from
about 0.1 to about 0.4.
[0039] In still another preferred mixed-metal oxide embodiment,
with reference to formula I, the sum of (a+b+c) is preferably less
than or not more than about 0.5, is preferably not more than about
0.4, and is even more preferably not more than about 0.3, and
moreover, this sum preferably ranges from about 0.04 to about 0.5,
more preferably from about 0.1 to about 0.4 and most preferably
from about 0.1 to about 0.3.
[0040] In an additional preferred mixed-metal oxide embodiment,
with reference to formula I: A is Ti, Ta, Nb or Zr, or preferably,
Ti, Ta or Nb; B is La, Ce, Pr, Nd, Sm, Sb, Sn, Bi, Cr, Co or Ag, or
preferably, La, Ce, Pr, Nd, Sm, Sb, Sn or Bi; and C is Ca, K or Mg.
In this embodiment, x ranges from about 0.1 to about 0.96, and
preferably from about 0.5 to about 0.96, a ranges from about 0.3 to
about 0.5, c ranges from about 0.01 to about 0.09, and preferably
from about 0.01 to about 0.05, and d is a number that satisfies
valence requirements.
[0041] In a further preferred mixed-metal oxide embodiment, with
reference to formula I, A is Ti and Ta in combination, Ti and Nb in
combination, or Ta and Nb in combination, B is La, Ce, Pr, Nd, Sm,
Sb, Sn, Bi, Co, Cr and Ag, and C is Ca, K or Mg. In this
embodiment, x ranges from about 0.1 to about 0.96, and preferably
from about 0.5 to about 0.96, a ranges from about 0.3 to about 0.5,
c ranges from about 0.01 to about 0.09, and preferably from about
0.01 to about 0.05, and d is a number that satisfies valence
requirements.
[0042] In a particularly preferred mixed-metal oxide embodiment,
with reference to formula I, A is Ti, B is Sb, Sn, Bi, Co, Ag or Ce
and C is Sr, Ca, Mg or Li. In this embodiment, x ranges from about
0.5 to about 0.9, a ranges from about 0.15 to about 0.4, c ranges
from 0 to about 0.05, and d is a number that satisfies valence
requirements.
[0043] In another particularly preferred mixed-metal oxide
embodiment, with reference to formula I, A is Ta, B is Sb, Sn, Bi,
Co, Ag or Ce and C is Sr, Ca, Mg or Li. In this embodiment, x
ranges from about 0.5 to about 0.9, a ranges from about 0.15 to
about 0.4, c ranges from 0 to about 0.05, and d is a number that
satisfies valence requirements.
[0044] In a further particularly preferred mixed-metal oxide
embodiment, with reference to formula I, A is Nb, B is Sb, Sn, Bi,
Co, Ag or Ce and C is Sr, Ca, Mg or Li. In this embodiment, x
ranges from about 0.5 to about 0.9, a ranges from about 0.15 to
about 0.4, c ranges from 0 to about 0.05, and d is a number that
satisfies valence requirements.
[0045] In still a further preferred embodiment, the nickel catalyst
of the invention can be a material comprising a mixed-metal oxide
compound having the formula II:
Ni.sub.xTi.sub.jTa.sub.kNb.sub.lLa*Sb.sub.rSn.sub.sBi.sub.tCa.sub.uK.sub.v-
Mg.sub.wO.sub.d (II),
[0046] where "x" and "d" are as described above, and La*, j, k, l,
r, s, t, u, v and w are described below, together with preferred
relationships between respective elements. The various recited
elements of formula II can be grouped in any of the various
combinations and permutations of preferences, some of which are
specifically set forth herein.
[0047] In formula II, each of "j", "k" and "l" represent a number
ranging from 0 to about 0.8, preferably from 0 to about 0.5, and
more preferably from 0 to about 0.4. The sum of (j+k+1) is at least
about 0.04, preferably at least about 0.1 5, and more preferably at
least about 0.3.
[0048] In formula II, La* refers to one or more lanthanide series
elements selected from the group consisting of La.sub.m, Ce.sub.n,
Pr.sub.n, Nd.sub.p, Sm.sub.q, and preferably. Each of "m", "n",
"o", "p", "q", "r", "s" and "t" refer to numbers ranging from 0 to
about 0.2, preferably from zero to about 0.1, and more preferably
from zero to about 0.05. The sum of (m+n+o+p+q+r+s+t) is preferably
at least about 0.005, more preferably at least about 0.01, and can,
in some embodiments, be at least about 0.05.
[0049] In formula II, each of "u", "v" and "w" refer to numbers
ranging from 0 to about 0.4, preferably from 0 to about 0.1 and
more preferably from 0 to about 0.05.
[0050] The nickel catalyst of the invention is preferably a
supported catalyst. The catalyst can therefore further comprise, in
addition to one or more of the aforementioned compounds or
compositions, a solid support or carrier. The support is preferably
a porous support, with a pore size typically ranging, without
limitation, from about 2 nm to about 100 nm and with a surface area
typically ranging, without limitation, from about 5 m.sup.2/g to
about 300 m.sup.2/g. The particular support or carrier material is
not narrowly critical, and can include, for example, a material
selected from the group consisting of silica, alumina, zeolite,
activated carbon, titania, zirconia, magnesia, zeolites and clays,
among others, or mixtures thereof. Preferred support materials
include titania, zirconia, alumina or silica. In some cases, where
the support material itself is the same as one of the preferred
components (e.g., Al.sub.2O.sub.3 for Al as a minor component), the
support material itself may effectively form a part of the
catalytically active material. In other cases, the support can be
entirely inert to the dehydrogenation reaction of interest. Titania
is a particularly preferred support, and can be obtained, for
example, from commercial vendors such as Norton, Degussa or
Engelhardt.
[0051] General approaches for preparing the nickel catalysts of the
present invention--as supported or unsupported catalysts--are well
known in the art. Exemplary approaches include, for example,
sol-gel, freeze drying, spray drying, precipitation, impregnation,
incipient wetness, spray impregnation, ion exchange, wet
mix/evaporation, dry mix/compacting, high coating, fluid bed
coating, bead coating, spin coating, physical vapor deposition
(sputtering, electron beam evaporation, laser ablation) and
chemical vapor deposition, among others. The particular technical
or non-technical technique employed is not narrowly critical.
Preferred approaches, include, for example, impregnation
techniques, precipitation techniques, sol-gel, evaporation,
incipient wetness and spray drying, among others. The catalyst may
take any suitable forms (e.g., granular, tablets, etc.), as
discussed in greater detail below.
[0052] According to one exemplary approach for preparing a
supported mixed-metal oxide catalyst of the invention, a
composition comprising each of the desired elements of the active
oxide components of the catalyst (i.e., the major component and one
or more minor components) can be formed, and then optionally
calcined to form the corresponding mixed-metal oxide. The
pre-calcination composition can be formed, in the first instance
for example, in a liquid state as a solution, dispersion, slurry or
sol, by combining the major component, the first minor
component(s), and optionally, the second and/or third minor
component(s). The pre-calcination composition can then be formed as
a solid having the same relative ratios of the various components,
for example, by being impregnated into, situated on, or formed
in-situ with the support or carrier (e.g., via precipitation or
sol-gel approaches). For example, a pre-calcination composition
formed as a solution or dispersion can be impregnated into or onto
the support, and then dried. Alternatively, pre-calcination
solution or dispersion can be precipitated, recovered and then
dried. A pre-calcination sol can be cured (gelled) to form the
corresponding solid composition. In any case, pre-calcination
compositions can be otherwise treated (e.g., heated) as desired
(e.g., to drive off solvents).
[0053] Preferred pre-calcination compositions of the invention can
comprise, or alternatively consist essentially of, a compound
represented by Formula I-B:
Ni.sub.xA.sub.aB.sub.bC.sub.c (I-B),
[0054] or salts thereof, where "x", "A", "B", "C", "a", "b" and "c"
are each as defined above in connection with the preferred
mixed-oxide catalyst. A particularly preferred pre-calcination
composition can comprise, or alternatively consist essentially of,
a compound represented by Formula II-B:
Ni.sub.xTi.sub.jTa.sub.kNb.sub.lLa*Sb.sub.rSn.sub.sBi.sub.tCa.sub.uK.sub.v-
Mg.sub.w (II-B),
[0055] or salts thereof, where "x", "j", "k", "La*", "r", "s", "t",
"u", "v" and "w" are each as defined above in connection with the
preferred mixed-oxide catalyst. The preferred pre-calcination
compositions can be in a liquid state (e.g., solution, dispersion,
slurry or sol) or a solid state.
[0056] According to one method for forming the preferred
pre-calcination composition, salts of the various elements are
combined to form a solution or liquid dispersion thereof,
("precursor solutions"). The metal salt precursor solutions are
preferably aqueous solutions, and can typically include metal
cations with counterions selected from nitrates, acetates,
oxalates, and halides, among others. The metal salt precursor
solutions can also be organic solutions or sol-gels comprising such
metal cations and counterions, as well as other counterions (e.g.,
alkoxides). When halides are used as a counterion, the resulting
catalyst is preferably subsequently rinsed extensively (e.g., with
water) to remove halide. Particularly preferred salts for Ni, Ti,
Nb, Ta and Zr include, for example, nickel nitrate, titanium
oxalate, niobium oxalate, tantalum oxalate, and zirconium oxalate.
The mixed-metal salt solutions can then be impregnated into a
support, preferably a titania support. The volume of mixed-metal
salt solutions used for impregnating the catalyst will depend on
the pore volume of the support, and can typically range from about
0.1 to about 2, preferably from about 0.1 to about 1 times the pore
volume thereof. The pH is preferably maintained at about 2 to about
6. The catalyst-impregnated support can then be dried, preferably
at reduced pressure (ie., under vacuum), at a temperature ranging
from about 20.degree. C. to about 100.degree. C. for a period of
time ranging from about 5 minutes to about 2 hours to form a
semi-solid or solid pre-calcination composition.
[0057] According to an alternative approach, various aqueous
solutions comprised of water-soluble metal precursors can be
combined in proper volumetric ratios to obtain combined solutions
(or mixtures) having desired metal compositions. Water can be
separated from the metal-salt components of the combined solutions
(or mixtures) by lyophilization, precipitation and/or evaporation.
Lyophilization refers to freezing the resulting mixture (e.g.,
under liquid nitrogen), and then placing the mixture in a high
vacuum so that the water (ice) sublimes, leaving behind mixtures of
dry metal precursors. Precipitation refers to separating dissolved
metal ions by adding one or more chemical reagents that will
precipitate sparingly soluble salts of the metal ions. Such
chemical reagents may provide ions that shift ionic equilibrium to
favor formation of insoluble metal salts (common ion effect), or
may bind with metal ions to form uncharged, insoluble coordination
compounds (complexation). In addition, such reagents may oxidize or
reduce metal ions to form ionic species that produce insoluble
salts. Other precipitation mechanisms include hydrolysis, in which
metal ions react with water in the presence of a weak base to form
insoluble metal salts, or the addition of agents (e.g., alcohols)
that affect the polarity of the solvent. Regardless of the
particular mechanism, the precipitate can be separated from the
remaining solution by first centrifuging the solutions and then
decanting the supernatant; residual water can be removed by
evaporation of water from the precipitates to form a semi-solid or
solid pre-calcination composition. Evaporation refers to removing
water by heating and/or under vacuum to form a semi-sold or solid
pre-calcination composition.
[0058] The solid pre-calcination composition can be calcined
according to methods known in the art. Calcination conditions can
affect the activity of the catalyst, and can be optimized by a
person of skill in the art, particularly in connection with a
particular catalyst composition and/or dehydrogenation reaction
conditions. Calcination is, without limitation, preferably effected
at temperatures ranging from about 250.degree. C. to about
600.degree. C., and more preferably from about 275.degree. C. to
about 400.degree. C. The calcination is preferably effected for
period of time, and at a temperature sufficient to provide the
desired metal oxide catalyst composition. Typically, calcination is
effected for a total, cumulative period of time of at least about
0.1 hour, and typically at least about 1 hour, with actual
calcination times depending on temperature according to approaches
known in the art. The calcination environment is preferably an
oxidizing environment (e.g., comprising air or other source of
molecular oxygen), but can also be an inert environment. In the
case of inert calcination, oxidation of the metal components of the
catalyst can be effected in situ during the reaction, by oxidizing
under reaction conditions. Hence, calcination can be effected prior
to loading the catalyst into a reaction zone, or alternatively, can
be effected in situ in the reaction zone prior to the reaction.
[0059] Finally, regardless of the particular approach used to form
the catalyst, the solid pre-calcination composition or the
calcination product (catalyst) can be ground, pelletized, pressed
and/or sieved to ensure a consistent bulk density among samples
and/or to ensure a consistent pressure drop across a catalyst bed
in a reactor. Further processing can also occur, as discussed
below.
[0060] The active catalyst of the invention can be included in a
catalyst composition comprising other, inactive components. The
catalyst may, for example, be diluted (e.g., have its concentration
reduced) with binders and/or inert fillers, which are known to
those of skill in the art, including for example quartz chips, sand
or cement. Diluents may be added to the catalyst in the range of
from about 0 to about 30% by volume, preferably in the range of
from about 10 to about 25% by volume. Preferred diluents can
improve the heat removal or heat transfer of the catalyst to help
avoid hot spots or to modify hot spots. Binders generally provide
mechanical strength to the catalyst and may be added in the range
of from about 0-30% by volume, preferably in the range of from
about 5 to about 25% by volume. Useful binders include silica sol,
silica, alumina, diamataceous earth, hydrated zirconia, silica
aluminas, alumina phosphates, naturally occurring materials and
cement and combinations thereof. See, e.g., the discussion of
supports, shapes, binders and fillers in U.S. Pat. Nos. 5,376,613,
5,780,700 and 4,250,346, each of which is incorporated herein by
reference for all purposes. The percentages or amounts of binders,
fillers or organics referred to herein relate to the starting
ingredients prior to calcination. Thus, the above is not intended
to imply statements on the actual bonding ratios, to which the
invention is not restricted; for example during calcination other
phases may form.
[0061] The catalyst or catalyst composition is provided to a
reaction zone of a reactor. The reactor is preferably a fixed-bed
flow reactor, but other suitable reactor designs--including batch
reactors and flow reactors (e.g., fluidized bed reactors)--can also
be employed. The catalyst is preferably provided in the reaction
zone (e.g., in a fixed-bed) as a supported catalyst, but may also
be provided as an unsupported catalyst (e.g., bulk, pelletized
catalyst). The catalyst may take any form, including powder, split,
granular, pellets or a shaped catalyst, such as tablets, rings,
cylinders, stars, ripped bodies, extrudates, etc., each of which
are known to those of skill in the art. For example, the shaping of
the mixture of starting composition may be carried out by
compaction (for example tableting or extrusion) with or without a
prior kneading step, if necessary with addition of conventional
auxiliaries (e.g., graphite or stearic acid or its salts as
lubricants). In the case of unsupported catalysts, the compaction
gives the desired catalyst geometry directly. Hollow cylinders may
have an external diameter and length of from 2 to 10 mm and a wall
thickness of from 1 to 3 mm. Generally, the mixture of starting
composition metal may be shaped either before or after the
calcination. This can be carried out, for example, by comminuting
or grinding the mixture before or after calcination and applying it
to inert supports to produce coated catalysts.
[0062] As discussed in greater detail below, co-catalysts can also
be provided to the reaction zone, together with the catalyst of the
present invention (in separate phases or as an integrated catalyst
composition).
[0063] An alkane or other reactant to be dehydrogenated is provided
to the reaction zone of the reactor containing the catalyst.
Typically and preferably, the dehydrogenation substrate reactant is
provided to the reaction zone as a gas or in a gaseous state.
Liquid reactants can be vaporized by methods and devices known in
the art and entrained in a moving stream of gaseous fluid.
[0064] The alkane can be substituted or unsubstituted. The alkane
is preferably an alkane having from 2 to 6 carbon atoms (a "C.sub.2
to C.sub.6 alkane") or a substituted C.sub.2 to C.sub.6 alkane, and
preferably an alkane having from 2 to 4 carbon atoms (a "C.sub.2 to
C.sub.4 alkane") or a substituted C.sub.2 to C.sub.4 alkane.
Preferred C.sub.2 to C.sub.6 alkane reactants include ethane,
propane, isopropanol, n-butane, isobutane, and isopentane, with
ethane being particularly preferred. The oxidative dehydrogenation
reaction for conversion of ethane to ethylene is
representative:
C.sub.2H.sub.6+1/2O.sub.2.fwdarw.C.sub.2H.sub.4+H.sub.2O
[0065] The corresponding alkenes for other preferred C.sub.2 to
C.sub.4 alkanes include propylene (from propane), acetone (from
isopropanol), 1-butene and/or 2-butene (from n-butane), isobutene
(from isobutane), isoamylenes (from isopentane), and isoprene.
Preferred substituted C.sub.2 to C.sub.4 alkanes include
halide-substituted C.sub.2 to C.sub.4. For example, ethyl chloride
can be oxidatively dehydrogenated using the catalysts and methods
described herein to form the vinyl chloride.
[0066] Although the present invention is described and exemplified
primarily in connection with dehydrogenation of the aforementioned
alkanes, dehydrogenation of other alkanes using the catalysts and
methods disclosed herein is also contemplated, and is within the
scope of the invention. For example, cyclohexane can be oxidatively
dehydrogenated over the nickel catalysts of the invention to form
benzene. Moreover, the nickel catalysts of the invention can also
be used for dehydrogenating other hydrocarbon substrates, such as
alkenes, to one or more dehydrogenation product(s). The
dehydrogenation of butene to form a butadiene, and the
dehydrogenation of isoamylenes to form isoprene are exemplary.
[0067] An oxidant is also provided to the reaction zone of the
reactor containing the catalyst. The oxidant is preferably a
gaseous oxidant, but can also include a liquid oxidant or a
solid-state oxidant. The gaseous oxidant is preferably molecular
oxygen, and can be provided as oxygen gas or as an
oxygen-containing gas. The oxygen containing gas can be air, or
oxygen or air that has been diluted with one or more inert gases
such as nitrogen. Other gaseous oxidants, such as N.sub.2O or NO,
can also be used in the oxidative dehydrogenation reaction. In
cases in which the alkane is oxidatively dehydrogenated in the
substantial absence of a gaseous oxidant during the reaction (e.g.,
using a solid oxidant), the oxidant may be periodically
regenerated--either by periodically withdrawing the catalyst from
the reaction zone or by regenerating the catalyst in situ in the
reaction zone (during or in-between reaction runs).
[0068] The sequence of providing the catalyst, reactant and oxidant
to the reaction zone is not critical. Typically, the catalyst is
provided in advance (or as noted above, even formed in situ in the
reaction vessel from a pre-calcination composition), and the alkane
gas and oxidant gas are provided subsequently--either together as a
mixed gas through a common feed line, or alternatively, separately,
but simultaneously, through different feed lines. In general, the
simultaneous supply of alkane and gaseous oxidant to the reaction
zone is referred to as "co-feed" regardless of the particular feed
configuration employed.
[0069] The amount of catalyst loaded to the reaction zone of the
reactor, together with the relative amounts of alkane (or other
reactant) and oxidant provided to the reaction zone, can vary, and
are preferably controlled--together with reaction conditions, as
discussed below--to effect the dehydrogenation reaction with
favorable and industrially attractive performance characteristics.
In general, the catalyst loading to the reaction zone will vary
depending on the type of reactor, the size of the reaction zone,
the form of the catalyst, required contact times, and/or the
desired amount or flow-rates of reactants and/or products. The
absolute amount of alkane or other reactant and oxidant can
likewise vary, depending primarily on the aforementioned factors,
and can be optimized by persons of skill in the art to achieve the
best performance. In general, lower oxidant concentration tends to
limit the extent of over-oxidation, and therefore, favor higher
alkene selectivity. Such lower oxidant concentrations, however, can
also adversely affect the alkane conversion. For conversion of
ethane to ethylene using molecular oxygen, for example, the molar
ratio of ethane to molecular oxygen, C.sub.2H.sub.6:O.sub.2, in the
reaction zone (or being fed to the reaction zone) can range from
about 1:1 to about 40:1, preferably from about 2:1 to about 40:1,
more preferably from about 66:34 to about 20:1, and most preferably
from about 5:1 to about 20:1. In some particularly preferred
embodiments--such as where multi-stage reactors are employed, as
discussed below--the C.sub.2H.sub.6:O.sub.2 ratio can preferably
range from about 5:1 to about 40:1, and preferably from about 5:1
to about 15:1, or alternatively, from about 10:1 to about 20:1. For
the conversion of gaseous alkanes such as ethane with molecular
oxygen, for example, the relative amounts of reactant and oxidant
can alternatively be expressed in terms of volume percentages in
reactor feed (for mixed-feed co-feed configuration) or in the
reaction zone (regardless of co-feed configuration), with molecular
oxygen preferably ranging from about 0.01% to about 34% by volume
and the alkane preferably ranging from about 66% to about 99% by
volume. The amount of molecular oxygen more preferably ranges from
about 0.01% to about 20% by volume, and the amount of alkane more
preferably ranges from about 80% to about 99% by volume.
Flammability limits should be observed for safety reasons.
[0070] Other materials may also be provided to the reaction zone.
For example, the reactor feed can also include diluents such as
nitrogen, argon or carbon dioxide. For some reactions, and/or for
some embodiments, discussed in greater detail below, the reactor
feed may comprise water vapor, or amounts of various reaction
products (e.g., alkenes such as ethylene, propylene or
butenes).
[0071] The alkane and the gaseous oxidant contact the catalyst in a
reaction zone of a reactor under controlled reaction conditions,
and the alkane is dehydrogenated to form the corresponding
alkene(s). Without being bound by theory, the alkane contacts the
catalyst in the presence of the oxidant and is dehydrogenated; the
hydrogen atoms combine with an oxygen from the oxidant to form the
corresponding alkene(s) and water as reaction products. Contact
between the reactant substrate, gaseous oxidant and catalyst can
occur, for example, as a mixture of the feed gasses passes through
or around the interstices of the fixed-bed catalyst and/or over an
exposed surface of the catalyst. The contact time (or residence
time) can vary, and can be optimized by persons of skill in the
art. Generally, and without limitation, contact times can range
from about 0.1 seconds to about 10 seconds, and preferably from
about 0.5 seconds to about 5 seconds. Without limitation, the gas
space velocity SV in the vapor phase reaction can range from about
100/hr to about 10,000/hr, preferably from about 300/hr to about
6,000/hr, and more preferably from about 300/hr to about 2,000/hr.
Inert gas(es) can be used, if desired, as a diluting gas to adjust
the space velocity. The temperature and pressure of the reaction
zone can likewise vary, and can likewise be optimized by persons of
skill in the art. Without limitation, the temperature preferably
ranges from about 200.degree. C. to about 500.degree. C., more
preferably from about 200.degree. C. to about 400.degree. C., even
more preferably from about 250.degree. C. to about 400.degree. C.,
still more preferably from about 250.degree. C. to about
350.degree. C., and yet more preferably from about 275.degree. C.
to about 325.degree. C., and most preferably from about 275.degree.
C. to about 300.degree. C. In one embodiment of the invention, the
temperature of the reaction zone during the dehydrogenation
reaction is preferably controlled to be less than about 300.degree.
C. Alkane oxidative dehydrogenation is an exothermic reaction, and
adequate heat transfer (cooling) can be achieved using methods
known in the art, including for example, cooling with steam.
Without limitation, the reaction pressure can range from
atmospheric pressure to about 20 bar, and preferably ranges from
about 1 bar to about 10 bar.
[0072] The relative alkane and oxidant feeds, catalyst loading, and
reaction conditions are preferably controlled, individually and
collectively among the various possible permutations, to achieve a
reaction performance that is suitable for industrial applications.
More specifically, the alkane and oxidant feeds, catalyst loading
and reaction conditions are controlled such that the alkane is
dehydrogenated to its corresponding alkene(s) with an alkane
conversion of at least about 5%, preferably at least about 10%, and
an alkene selectivity of at least about 70%, and preferably at
least about 75%. Using the catalysts and process disclosed herein,
the aforementioned reaction parameters can be controlled to achieve
a conversion of at least about or greater than 15%, and more
preferably at least about 20% or higher, and to achieve a
selectivity for the alkene of at least about or greater than about
80%, preferably at least about or greater than about 85%, and most
preferably at least about or greater than about 90%. Within
experimental error, selectivity is substantially independent of
conversion.
[0073] As used herein, "conversion" refers to the percentage of the
amount of alkane provided to the reaction zone that is converted to
carbon products, and can be expressed as follows: 1 % conversion =
100 .times. The molar alkane - equivalent sum ( carbon basis ) of
all carbon - containing products , excluding the alkane in the
effluent . Moles of alkane in the reaction mixture which is fed to
the catalyst in the reactor
[0074] As used herein, "selectivity" (also known as efficiency), or
equivalently, "alkene selectivity" refers to the percentage of the
amount of converted alkane (i.e., total carbon products) that is
converted to the specifically desired alkene product, and can be
expressed as follows: 2 % selectivity = 100 .times. Moles of
desired alkene produced The molar alkene - equivalent sum ( carbon
basis ) of all carbon - containing products , excluding the alkane
in the effluent .
[0075] These expressions are the theoretical expressions for
selectivity and conversion. Simplified formulas have been used in
the examples herein, and may be Used by those of skill in the art
for alkane oxydehydrogenation reactions where CO.sub.2 is the
primary side product--for example, where the only products observed
in the ethane oxidative dehydrogenation (using an ethane and
molecular oxygen gas feed) are ethylene and carbon dioxide. In such
cases, the simplified formula for % conversion is %
conversion=100.times.[(moles of alkene+((moles of carbon
dioxide)/2))/(moles of alkane)]. The simplified formula for %
selectivity is % selectivity =100.times.[(moles of alkene)/(moles
of alkene+((moles of carbon dioxide)/2))]. When the alkane is
ethane or propane, only one dehydrogenation product is possible,
and the calculations are straightforward. When butane is the
alkane, however, the dehydrogenation product can be one or more of
1-butene, 2-butene or 1,3-butadiene. Thus, for butane
dehydrogenation reactions, the percentages for selectivity and
conversion may be based on one or more of these butane
dehydrogenation products.
[0076] The nickel oxide/mixed-metal oxide catalysts of the present
invention offer significant performance advantages as compared to
current industrially-important (V-Mo) catalysts. For example, the
catalysts of the invention can result in about a 20% conversion
with about a 90% selectivity, as compared to about a 5% conversion
with a 90% selectivity of the current industrially-important
alternative. Moreover, the space-time yield achieved based on
bulk-scale testing of the invention catalysts in laboratory-scale
equipment is about 300 kg ethylene produced per m.sup.3 of catalyst
per hour--an improvement of a factor of about ten (10) as compared
to known MoV-based catalysts.
[0077] The nickel oxide/mixed-metal oxide catalysts of the present
invention are stable with respect to dehydrogenation activity and
performance characteristics. Stability of the catalyst is
demonstrated by lifetime testing, in which a C.sub.2 to C.sub.4
alkane or a substituted C.sub.2 to C.sub.4 alkane and a gaseous
oxidant are co-fed to a reaction zone containing the catalyst while
maintaining the reaction zone (and the catalyst) at temperature
ranging from about 200.degree. C. to about 500.degree. C.,
preferably from about 250.degree. C. to about 350.degree. C., and
more preferably from about 250.degree. C. to about 300.degree. C.
The alkane is contacted with the catalyst in the presence of the
gaseous oxidant to dehydrogenate the alkane and to form the
corresponding alkene. The alkene, unreacted alkane and unreacted
gaseous oxidant are exhausted or otherwise removed from the
reaction zone. The steps of co-feeding the reactants,
dehydrogenating the alkane, and exhausting the alkene and unreacted
reactants are effected for a cumulative reaction period of not less
than about 200 hours, preferably not less than about 400 hours,
more preferably not less than about 600 hours, even more preferably
not less than about 1000 hours, and most preferably not less than
about 2000 hours. In commercial industrial-scale applications, the
catalyst is preferably stable for at least about 5000 hours, and
more preferably at least about 8000 hours.
[0078] Significantly, the nickel-containing mixed-metal oxide
catalyst of the present invention has activity for selectively
converting alkane to the corresponding alkene/olefin (e.g., ethane
to ethylene) even in the presence of substantial amounts of
alkene/olefin (e.g., ethylene) in the reaction zone. Specifically,
the alkane can be oxidatively dehydrogenated to form the
corresponding alkene in the reaction zone--even when the reaction
zone comprises the corresponding alkene in a molar concentration of
at least about 5%, relative to total moles of hydrocarbon, during
the oxydehydrogenation--with an alkane conversion of at least about
5% and an alkene selectivity of at least about 50%. A conversion of
at least about 5% and a selectivity of at least about 50% can
likewise be achieved where the molar concentration of the
corresponding alkene in the reaction zone ranges from about 5% to
about 50%, or where the molar concentration thereof is at least
about 10%, at least about 20%, at least about 30%, at least about
40% or at least about 50%, relative to total moles of hydrocarbon.
Moreover, alkane conversions as high as 10% with alkene selectivity
as high as 70% can be achieved where the molar concentration the
corresponding alkene in the reaction zone is at least about 30%
relative to total moles of hydrocarbon. The relatively low
product-sensitivity of the catalyst activity is surprising,
particularly with respect to ethane conversion, because ethylene is
typically more reactive than ethane over most catalysts.
[0079] The lack of product-inhibition on catalyst activity can be
advantageously employed in a number of ways. First, for example, a
less-pure, mixed feed comprising both alkane and the corresponding
alkene can be selectively enriched in the alkene. For example, a
70% ethane/30% ethylene feed stream, by volume, can be enriched by
conversion to a 60% ethane/40% ethylene product stream, by volume,
or further, to a 50% ethane/50% ethylene product stream, by volume.
As a more specific example, raffinate II (a mixture of butane,
2-butenes and 1-butene gasses) can be selectively enriched in the
butenes at the expense of butane, ultimately resulting in a more
uniform stream composition. Such enrichment schemes may be
particularly important if employed in connection with separation
schemes that are more effective with streams having higher alkene
content.
[0080] As another embodiment, exemplary of the advantageous
catalytic activity of the catalyst, a single-stage reactor system
can be configured to recycle the product stream (or a portion
thereof) back to the feed stream, resulting in an overall
improvement in conversion and selectivity. More specifically, with
reference to FIG. 1A, the alkane (e.g., C.sub.2H.sub.6) and gaseous
oxidant (e.g., O.sub.2) are co-fed through feed conduits 5 to a
reaction zone 10 containing the catalyst 100, the alkane is
dehydrogenated in the reaction zone 10 to form the corresponding
alkene, the resulting product stream 15 (comprising the
corresponding alkene, unreacted alkane and optionally any excess
gaseous oxidant) is exhausted from the reaction zone 10, and a
portion or all of the alkene- and unreacted-alkane-containing
product stream 15 is then recycled back to the reaction zone via
recycle line 25 (and is typically recombined with a fresh feed
stream 5). As a variation of the basic recycling embodiment
discussed in the immediately-preceding paragraph, the product
stream can be partially separated after being exhausted and before
being recycled.
[0081] In a further, and generally preferred embodiment
exemplifying the aforementioned advantage, a multi-stage reaction
system can be effected, in which the product stream from a first
reaction zone, or a portion thereof, becomes the feed stream for a
second reaction zone. More specifically, with reference to FIG. 1B,
an alkane (e.g., C.sub.2H.sub.6) and a gaseous oxidant (e.g.,
O.sub.2) can be co-fed through feed conduits 5 to a first reaction
zone 10, in which the alkane is dehydrogenated to form the
corresponding alkene, and the first product stream 15 comprising
the corresponding alkene and unreacted alkane from the first
reaction zone 10 is exhausted therefrom. The alkene- and
unreacted-alkane-containi- ng product stream 15 from the first
reaction zone is then fed to a second reaction zone 20--preferably
with a co-feed of fresh gaseous oxidant via feed conduit 5' to the
second reaction zone 20. The alkane is further dehydrogenated in
the second reaction zone 20 to form the corresponding alkene
therein. The alkene product is exhausted from the second reaction
zone 20 as a product stream 15'. Additional stages of reaction
zones (in one or more reactors) can likewise be added. The second
(or further additional) reaction zone(s) preferably comprises the
alkene at a molar concentration of at least about 5% relative to
total moles hydrocarbon, and can be higher up to about 50%, as well
as at one or more of the intermediate levels as described above.
Significantly, because fresh gaseous oxidant (e.g., molecular
oxygen) can be added between each stage of the multi-stage reactor,
the amount of gaseous oxidant can be controlled at each stage to
achieve an optimized selectivity and conversion for the
dehydrogenation reaction occurring in that stage. This is
particularly advantageous because low oxidant concentrations in the
feed typically favor more selective oxydehydrogenation reactions,
with less formation of side-product (e.g., carbon dioxide). In
preferred embodiments for ethane dehydrogenation to ethylene, the
molar concentration of oxygen in the first and second reaction
zones is controlled to range from about 3% to about 40%, preferably
from about 3% to about 20%, more preferably from about 5% to about
20%, and most preferably from about 8% to about 15%, in each case
relative to ethane. The overall conversion and selectivity for
ethane dehydrogenation to ethylene with a multi-stage,
multi-low-level oxygen co-feed system as described herein is
preferably at least about 5% alkane conversion and at least about
70% alkene selectivity, preferably at least about 80% alkene
selectivity, preferably at least about 85% alkene selectivity, and
more preferably at least about 90% alkene selectivity, and in
another embodiment, preferably at least about 10% alkane conversion
and at least about 80% alkene selectivity, preferably at least
about 85% alkene selectivity, and more preferably at least about
90% alkene selectivity. In particularly preferred embodiments, the
overall conversion is at least about 30%, more preferably at least
about a value ranging from about 30% to about 45%, and the overall
selectivity is at least about 70%, more preferably at least about a
value ranging from about 70% to about 85%.
[0082] Regardless of the particular reactor-configuration (e.g.,
single-stage, single-stage with recycle, multi-stage, multi-stage
with multi-oxidant feed, etc.), the resulting product stream
typically comprises the product alkene/olefin of interest, together
with unreacted alkane, possibly unreacted gaseous oxidant, as well
as any side-product (e.g., CO.sub.2). The desired alkene product
can be separated from the reaction product stream by methods known
in the art. Preferably, for example, the alkene product can be
recovered from the reaction product stream by cryogenic separation,
by pressure-swing adsorption (e.g., on zeolites), by selective
absorption. Additionally, or alternatively, the reaction product
stream can be used, without further separation or with partial
separation (e.g., with removal of CO.sub.2) as a feedstream to a
downstream reactor, where the alkene product can be reacted further
(e.g., as discussed below).
[0083] The oxydehydrogenation products of the reactions disclosed
herein (e.g., ethylene, propylene, butenes, pentenes) can be
further reacted to form a number of commercially important
downstream products.
[0084] Ethylene produced by the oxydehydrogenation of ethane using
the nickel oxide/mixed-metal oxide catalyst of the present
invention can, for example, be further reacted to form
polyethylene, styrene, ethanol, acetaldehyde, acetic acid, vinyl
chloride, ethylene oxide, ethylene glycol, ethylene carbonate,
ethyl acetate and vinyl acetate, among others. More specifically,
ethylene can be formed by oxidatively dehydrogenating ethane in the
presence of a catalyst comprising (i) Ni, a Ni oxide, a Ni salt or
mixtures thereof, and (ii) elements or compounds selected from the
group consisting of Ti, Ta, Nb, Hf, W, Y, Zn, Zr, Al, oxides
thereof, and salts thereof, or mixtures of such elements or
compounds. The catalyst can be more specifically characterized as
described above. The ethylene can be optionally purified, and then
further reacted to form a downstream reaction product of ethylene
according to one or more of the following schemes.
[0085] Polyethylene. Ethylene can be polymerized to form
polyethylene according to methods known in the art using a catalyst
having activity for polymerizing ethylene to polyethylene.
Exemplary polymerization approaches include free-radical
polymerization, and polymerization over Ziegler (i.e., metal alkyl)
catalysts. Styrene. Ethylene can be reacted with benzene in the
presence of acid catalysts such as aluminum chloride or zeolites to
form ethylbenzene, which can be catalytically dehydrogenated (using
a catalyst of the invention or known dehydrogenation catalysts) to
form styrene. Styrene can also be formed directly from the reaction
of ethylene with benzene. Ethanol. Ethylene can be hydrated to form
ethanol according to methods known in the art using a catalyst
comprising an element or compound having activity for hydrating
ethylene to ethanol. Preferred ethylene hydration catalysts include
oxides of B, Ga, Al, Sn, Sb or Zn, or mixtures of such oxides.
Water is preferably cofed to the reaction zone during the hydration
reaction. Acetaldehyde. Acetaldehyde can be formed from ethylene
according to methods known in the art--either directly, or through
an ethanol intermediate. In a direct route, ethylene is oxidized to
acetaldehyde using a catalyst comprising an element or compound
having activity for oxidizing ethylene to acetaldehyde. Preferred
ethylene oxidation catalysts for acetaldehyde formation include
oxides of Pd, Cu, V or Co, or mixtures of such oxides. In an
alternative, indirect route, ethylene is hydrated to form ethanol
(as described above) and ethanol is then oxidized to form
acetaldehyde in the presence of a catalyst having activity for
oxidizing ethanol to acetaldehyde. Preferred ethanol oxidation
catalysts for acetaldehyde formation include metals and/or metal
oxides of Cu, Co, Ag, Re, Ru, Pt, Bi, Ce, Sb, In, Pd, Rh, Ir, V, Cr
or Mn, or mixtures of such oxides. Acetic Acid. Ethylene can be
oxidized to form acetic acid according to methods known in the art
using a catalyst comprising an element or compound having activity
for oxidizing ethylene to acetic acid. The catalyst preferably
comprises a noble metal or an oxide thereof, and more preferably,
Pd or Pt or oxides thereof. Water is preferably co-fed to the
reaction zone during the ethylene oxidation reaction. Vinyl
Chloride. Ethylene can be chlorinated or oxychlorinated to form
vinyl chloride according to methods known in the art. In a
chlorination reaction, chlorine or other chlorinating agent are
preferably co-fed to the reaction zone, and ethylene is chlorinated
in the presence of a catalyst having activity for chlorinating
ethylene to vinyl chloride, or alternatively, in the absence of a
catalyst. Preferred ethylene chlorination catalysts for preparing
vinyl chloride comprise a metal halide or metal oxyhalide, and
preferably, a halide or oxyhalide of Cu, Fe or Cr. In an
oxychlorination reaction, a gaseous oxidant and HCl or other
chlorinating agent are preferably co-fed to the reaction zone, and
ethylene is oxychlorinated in the presence of a catalyst having
activity for oxychlorinating ethylene to vinyl chloride. Preferred
ethylene oxychlorination catalysts for preparing vinyl chloride
comprise a metal halide or metal oxyhalide, and most preferably, a
halide or oxyhalide of Cu, Fe or Cr. Ethylene Oxide. Ethylene can
be oxidized to form ethylene oxide according to methods known in
the art using a catalyst comprising an element or compound having
activity for oxidizing ethylene to ethylene oxide. The catalyst
preferably comprises Ag, a halide thereof, an oxide thereof or a
salt thereof. Ethylene Glycol. Ethylene glycol can be produced by
oxidizing ethylene to form ethylene oxide as described above, and
hydrating ethylene oxide to form ethylene glycol. Alternatively,
ethylene can be converted into ethylene glycol directly, in a
single-step process. Ethylene Carbonate. Ethylene carbonate can be
produced from ethylene by reacting ethylene with carbon dioxide or
carbon monoxide to form ethylene carbonate, or alternatively by
forming ethylene glycol as described above and then reacting the
ethylene glycol with phosgene. Ethyl acetate. Ethyl acetate can be
formed from acetic acid, prepared as described above, according to
methods known in the art. Vinyl acetate. Vinyl acetate can be
prepared by vapor-phase reaction of ethylene, acetic acid and
oxygen over a Pd catalyst.
[0086] Propylene produced by the oxydehydrogenation of propane
using the nickel oxide/mixed-metal oxide catalyst of the present
invention can, for example, be further reacted to form
polypropylene, acrolein, acrylic acid, acetone, propylene oxide and
propylene carbonate, among other downstream reaction products of
propylene. More specifically, propylene can be formed by
oxidatively dehydrogenating propane in the presence of a catalyst
comprising (i) Ni, a Ni oxide, a Ni salt or mixtures thereof, and
(ii) elements or compounds selected from the group consisting of
Ti, Ta, Nb, Hf, W, Y, Zn, Zr, Al, oxides thereof, and salts
thereof, or mixtures of such elements or compounds. The catalyst
can be more specifically characterized as described above. The
propylene can be optionally purified, and then further reacted
according to one or more of the following schemes.
[0087] Polypropylene. Propylene can be polymerized to form
polypropylene according to methods known in the art using a
catalyst having activity for polymerizing propylene to
polypropylene. Exemplary propylene polymerization catalysts
include, for example, aluminum alkyl catalysts. Acrolein. Propylene
can be oxidized to form acrolein according to methods known in the
art using a catalyst comprising an element or compound having
activity for oxidizing propylene to acrolein. The catalyst
preferably comprises an oxide of Bi, Mo, Te or W, or mixtures of
such oxides. Acrylic Acid. Propylene can be oxidized to form
acrylic acid according to methods known in the art using a catalyst
comprising an element or compound having activity for oxidizing
propylene to acrylic acid. The catalyst preferably comprises an
oxide of Mo, V or W, or mixtures of such oxides. Acetone. Acetone
can be produced from propylene by oxidation of propylene. Propylene
Oxide. Propylene can be oxidized to form propylene oxide according
to methods known in the art using a catalyst comprising an element
or compound having activity for oxidizing propylene to propylene
oxide. The catalyst preferably comprises TiSi oxide or PdTiSi oxide
catalysts. Propylene carbonate. Propylene carbonate can be formed
by preparing propylene oxide as described above, and by reacting
the propylene oxide with carbon dioxide. Propylene can also be
directly converted to propylene carbonate in a single-step
process.
[0088] The oxydehydrogenation products of isobutane and n-butane
can likewise be further reacted. Isobutene can be further reacted,
for example, to form methacrylic acid. n-Butene can be further
reacted, for example, to form butanol, butanediol, butadiene,
methylethylketone (MEK), methylvinylketone (MVK), furane, or
crotonaldehyde. More specifically, isobutene or n-butene can be
formed by oxidatively dehydrogenating the respective butane in the
presence of a catalyst comprising (i) Ni, a Ni oxide, a Ni salt or
mixtures thereof, and (ii) elements or compounds selected from the
group consisting of Ti, Ta, Nb, Hf, W, Y, Zn, Zr, Al, oxides
thereof, and salts thereof, or mixtures of such elements or
compounds. The catalyst can be more specifically characterized as
described above. The isobutene or n-butene can be optionally
purified, and then further reacted according to one or more of the
following schemes.
[0089] Methacrylic Acid. Isobutene can be oxidized to form
methacrylic acid according to methods known in the art using a
catalyst comprising an element or compound having activity for
oxidizing isobutene to methacrylic acid. The catalyst preferably
comprises a polyoxometallate (POM), and in particular, PVMo- or
PVW-containing POM. Butanol. Butanol can be prepared by hydrating
n-butene to form butanol. Butadiene. n-Butene can be oxidatively
dehydrogenated to form butadiene according to the methods of the
present invention (and/or according to other methods known in the
art) using a catalyst comprising an element or compound having
activity for oxidatively dehydrogenating n-butene to butadiene. The
catalyst preferably comprises (i) Ni, a Ni oxide, a Ni salt or
mixtures thereof, and (ii) elements or compounds selected from the
group consisting of Ti, Ta, Nb, Hf, W, Y, Zn, Zr, Al, oxides
thereof, and salts thereof, or mixtures of such elements or
compounds. The catalyst can be more specifically characterized as
described above. Butanediol. Butane diol can be prepared by forming
butadiene, as described above, and then hydrating butadiene to form
butanediol. Methylethylketone (MEK). n-Butene can be oxidatively
dehydrogenated to form butadiene (as described above), and
butadiene can be oxidized to form methylethylketone (MEK) according
to the methods known in the art using a catalyst comprising an
element or compound having activity for oxidation of butadiene to
MEK. The catalyst preferably comprises Bi/Mo, Mo/V/W, VPO or a
polyoxometallate. Methylvinylketone (MVK). n-Butene can be
oxidatively dehydrogenated to form butadiene (as described above),
and butadiene can be oxidized to form methylvinylketone (MVK)
according to the methods known in the art using a catalyst
comprising an element or compound having activity for oxidation of
butadiene to MVK. The catalyst preferably comprises Bi/Mo, Mo/V/W,
VPO or a polyoxometallate. Furane. Furane can be prepared by
oxidizing n-butene. Crotonaldehyde. Crotonaldehyde can be prepared
by forming butadiene, as described above, and then oxidizing
butadiene to form crotonaldehyde.
[0090] In each of the aforementioned further reactions of the
oxydehydrogenation products (e.g., ethylene, propylene, butenes),
the reactants are preferably provided to the reaction zone in the
presence of the respective catalysts. The catalyst(s) for the
downstream reaction(s) can be co-catalysts provided to the same
reaction zone in which the oxydehydrogenation catalyst is situated,
or alternatively, can be provided to a physically separate,
down-stream reaction zone. If provided as a co-catalyst in the same
reaction zone, the catalyst for the downstream reaction can be
prepared and provided to the reaction zone as a separate
composition from the catalyst of the present invention, or
alternatively, can be prepared and provided to the reaction zone as
a single composition in separate phases or as an integrated
catalyst composition having activity for both the
oxydehydrogenation reaction and the respective downstream reaction
of interest. Regardless of whether the oxydehydrogenation reaction
and the downstream reaction of interest are carried out in the same
or in separate reaction zones, the oxydehydrogenation reaction and
the downstream reaction(s) are preferably performed sequentially
(e.g., where an alkane is oxydehydrogenated to form the
corresponding alkene as the oxydehydrogenation product, and the
alkene is then further reacted to form the downstream product of
interest).
[0091] The following examples illustrate the principles and
advantages of the invention.
EXAMPLES
[0092] General.
[0093] In general, catalysts were prepared in small quantities
(e.g. .about.100 mg) or in larger, bulk quantities (e.g., .about.20
g) using conventional precipitation and/or evaporation approaches.
Small quantity catalysts were generally prepared with automated
liquid dispensing robots (Cavro Scientific Instruments) in glass
vials contained in wells of an aluminum substrate. Catalysts were
screened for activity for oxidative dehydrogenation of ethane
(ODHE), regardless of the scale of preparation, in a parallel fixed
bed reactor substantially as disclosed in PCT patent application WO
99/64160 (Symyx Technologies, Inc.).
Example 1
ODHE Over NiNbTi Oxide and NiTaTi Oxide Catalysts.
(#14839/15156)
[0094] Catalysts were prepared in small quantities (.about.100 mg)
from nickel nitrate ([Ni]=1.0 M), titanium oxalate ([Ti]=0.713 M),
niobium oxalate ([Nb]=0.569 M), and tantalum oxalate ([Ta]=0.650 M)
aqueous stock solutions by precipitation with tetramethylammonium
hydroxide ([NMe.sub.4OH]=1.44M). Briefly, a library of catalyst
precursors were prepared by dispensing various amounts of aqueous
stock solutions using a Cavro automated liquid handling robot to an
array of glass vials held in an aluminum substrate. The
precipitating agent, NMe.sub.4OH solution, was added to the various
catalyst precursor compositions in about 1.3 equivalent of acid and
metal ions, by high-speed injection from a syringe head. The
high-speed injection of the base provides mixing of the catalyst
precursor solution and precipitation agents, thereby effecting
precipitation of solid catalyst materials. To further insure well
mixing, additional liquid (e.g., distilled water was, in some
cases, also injected into the vial containing the metal precursor
solution and base precipitating agent. The resulting precipitate
mixtures were allowed to settle at about 25.degree. C. for about 2
hours, and were then centrifuged at 3000 rpm to separate solid
precipitate from the solution. The solution was decanted and solids
were dried under vacuum at 60.degree. C. in a vacuum oven. Table 1A
summarizes the composition and amounts of the various catalyst
compositions.
[0095] In a first set of experiments, the dried catalyst
compositions were calcined to 300.degree. C. in an atmosphere of
air with an oven temperature profile: ramp to 300.degree. C. at
2.degree. C./min and dwell at 300.degree. C. for 8 hours. Samples
were ground with a spatula. The mixed metal oxide catalysts
(.about.50 mg) were screened in the fixed bed parallel reactor. The
performance characteristics of these catalysts for ethane oxidative
dehydrogenation at 300.degree. C. with relative flowrates of
ethane:nitrogen:oxygen of 0.42:0.54:0.088 sccm are summarized in
Table 1B (ethane conversion) and Table 1C (ethylene
selectivity).
[0096] After initial screening, these catalyst were subsequently
recalcined to 400.degree. C. with a similar temperature profile.
The performance characteristics of these catalysts for ethane
oxidative dehydrogenation in the parallel fixed bed reactor at
300.degree. C. with relative flowrates of ethane:nitrogen:oxygen of
0.42:0.54:0.088 sccm are summarized in Table 1D (ethane conversion)
and Table 1E (ethylene selectivity).
1TABLE 1A Catalyst composition (mole fraction) of Ni--Nb--Ti and
Ni--Ta--Ti oxide mixtures and sample mass, "m" (mg) used in
parallel fixed bed reactor screen. Col Row 1 2 3 4 5 6 1 Ni 1.0000
0.8969 0.7944 0.6927 0.5917 0.4914 Nb 0.0000 0.0000 0.0000 0.0000
0.0000 0.0000 Ta 0.0000 0.1031 0.2056 0.3073 0.4083 0.5086 Ti
0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 m 49.5 50.4 50 49.4 50.1
50.1 2 Ni 0.9119 0.9091 0.8052 0.7021 0.5997 0.4980 Nb 0.0881
0.0000 0.0000 0.0000 0.0000 0.0000 Ta 0.0000 0.0000 0.1042 0.2076
0.3103 0.4124 Ti 0.0000 0.0909 0.0906 0.0903 0.0900 0.0896 m 50.2
49.5 50.3 50.5 49.6 49.8 3 Ni 0.8214 0.8188 0.8163 0.7117 0.6079
0.5048 Nb 0.1786 0.0890 0.0000 0.0000 0.0000 0.0000 Ta 0.0000
0.0000 0.0000 0.1052 0.2097 0.3135 Ti 0.0000 0.0921 0.1837 0.1830
0.1824 0.1817 m 49.5 49.5 49.3 50.4 50 50.3 4 Ni 0.7284 0.7261
0.7239 0.7216 0.6163 0.5118 Nb 0.2716 0.1805 0.0900 0.0000 0.0000
0.0000 Ta 0.0000 0.0000 0.0000 0.0000 0.1063 0.2119 Ti 0.0000
0.0934 0.1861 0.2784 0.2774 0.2764 m 49.3 49.4 49.3 50.1 49.4 49.3
5 Ni 0.6329 0.6309 0.6289 0.6270 0.6250 0.5189 Nb 0.3671 0.2744
0.1824 0.0909 0.0000 0.0000 Ta 0.0000 0.0000 0.0000 0.0000 0.0000
0.1074 Ti 0.0000 0.0946 0.1887 0.2821 0.3750 0.3736 m 50.3 50.3
49.3 49.9 49.6 50.4 6 Ni 0.5348 0.5330 0.5314 0.5297 0.5280 0.5263
Nb 0.4652 0.3710 0.2774 0.1843 0.0919 0.0000 Ta 0.0000 0.0000
0.0000 0.0000 0.0000 0.0000 Ti 0.0000 0.0959 0.1913 0.2860 0.3801
0.4737 m 50.7 22.6 50.4 49.5 49.9 50.6
[0097]
2TABLE 1B Ethane conversion for the catalysts in Table 1A. Test
conditions: 300.degree. C. with ethane/nitrogen/oxygen flow of
0.42/0.54/0.088 sccm. Ethane Conversion (%) of Ni--Nb--Ta--Ti Oxide
Mixtures 1 2 3 4 5 6 1 9.4 17.9 19.0 19.1 18.6 16.8 2 16.3 15.7
18.1 17.1 17.6 19.2 3 18.6 18.3 18.9 17.6 19.3 18.6 4 19.4 18.2
19.4 18.6 18.9 19.2 5 19.4 18.9 16.5 19.1 18.6 17.1 6 19.0 16.2
17.9 18.0 16.8 16.8
[0098]
3TABLE 1C Ethylene selectivity for the catalysts in Table 1A. Test
conditions: 300.degree. C. with ethane/nitrogen/oxygen flow of
0.42/0.54/0.088 sccm. Ethylene Selectivity (%) of Ni--Nb--Ta--Ti
Oxide Mixtures 1 2 3 4 5 6 1 47.2 82.8 84.3 83.7 84.7 83.3 2 79.5
78.5 84.2 85.0 81.2 84.9 3 84.5 83.6 83.5 84.1 84.4 85.0 4 84.2
84.1 83.4 84.1 84.8 84.8 5 84.8 84.9 82.1 82.3 82.1 83.8 6 82.6
81.1 79.9 80.5 78.8 79.0
[0099]
4TABLE 1D Ethane conversion for the catalysts in Table 1A but
recalcined to 400.degree. C. Test conditions: 300.degree. C. with
ethane/nitrogen/oxygen flow of 0.42/0.54/0.088 sccm. Ethane
Conversion (%) of Ni--Nb--Ta--Ti Oxide Mixtures 1 2 3 4 5 6 1 5.8
11.9 12.2 12.4 11.8 9.6 2 9.8 9.2 11.5 9.2 11.3 13.0 3 12.0 12.7
11.1 12.0 13.8 12.3 4 12.8 11.5 13.3 11.1 10.1 11.9 5 13.5 12.0
12.9 11.1 11.9 10.4 6 13.0 9.0 13.0 13.6 11.3 11.0
[0100]
5TABLE 1E Ethylene selectivity for the catalysts in Table 1A but
recalcined to 400.degree. C. Test conditions: 300.degree. C. with
ethane/nitrogen/oxygen flow of 0.42/0.54/0.088 sccm. Ethylene
Selectivity (%) of Ni--Nb--Ta--Ti Oxide Mixtures 1 2 3 4 5 6 1 34.2
83.1 85.4 84.4 85.2 85.1 2 77.2 75.3 84.9 86.4 80.8 84.6 3 85.1
84.1 82.7 84.0 83.8 84.1 4 85.4 84.5 83.7 82.2 83.9 84.5 5 86.4
85.9 79.3 78.7 80.4 83.1 6 80.1 78.4 79.3 77.1 72.1 71.2
[0101] Another library of NiNbTi oxide catalysts was prepared
substantially as described above and having the composition and
amounts summarized in Table 1F. The performance characteristics of
these catalysts for ethane oxidative dehydrogenation in the
parallel fixed bed reactor at 300.degree. C. with relative
flowrates of ethane:nitrogen:oxygen of 0:42:0.54:0.088 sccm are
summarized in Table 1G (ethane conversion) and Table 1H (ethylene
selectivity).
6TABLE 1F Catalyst composition (mole fractions) of NiNbTi oxide
catalysts and sample mass (mg) used in parallel fixed bed reactor
screen. Column Row 1 2 3 4 5 6 1 Ni 1.000 Nb 0.000 Ti 0.000 mass
49.9 (mg) 2 Ni 0.841 0.885 Nb 0.000 0.115 Ti 0.159 0.000 mass 45.0
56.3 (mg) 3 Ni 0.714 0.748 0.784 Nb 0.000 0.103 0.216 Ti 0.286
0.150 0.000 mass 49.2 49.3 45.0 (mg) 4 Ni 0.612 0.637 0.665 0.696
Nb 0.000 0.093 0.194 0.304 Ti 0.388 0.270 0.141 0.000 mass 49.6
51.4 51.9 50.8 (mg) 5 Ni 0.526 0.546 0.568 0.592 0.617 Nb 0.000
0.085 0.176 0.275 0.383 Ti 0.474 0.369 0.256 0.133 0.000 mass 44.9
46.3 46.7 44.0 47.0 (mg) 6 Ni 0.455 0.471 0.488 0.506 0.526 0.547
Nb 0.000 0.078 0.161 0.251 0.348 0.453 Ti 0.545 0.452 0.351 0.243
0.126 0.000 mass 48.8 50.5 46.1 48.5 52.0 54.1 (mg)
[0102]
7TABLE 1G Ethane conversion for catalysts listed in Table 1F. Test
conditions: 300.degree. C. with ethane:nitrogen:oxygen flow of
0.42:0.54:0.088 sccm. 1 2 3 4 5 6 1 8.4 2 16.6 18.2 3 17.5 16.5
16.9 4 16.7 16.3 17.0 16.1 5 15.9 16.2 17.1 15.9 17.9 6 16.6 17.5
15.5 15.2 17.2 14.4
[0103]
8TABLE 1H Ethylene selectivity for catalysts listed in Table 1F.
Test conditions: 300.degree. C. with ethane:nitrogen:oxygen flow of
0.42:0.54:0.088 sccm. 1 2 3 4 5 6 1 43.3 2 81.5 82.8 3 83.1 81.9
82.5 4 82.5 77.2 83.1 83.5 5 77.8 78.4 77.9 78.1 80.6 6 77.8 76.9
75.4 78.8 80.1 73.0
Example 2
ODHE Over NiNbTaTi Oxide Catalysts. (#16160/16223)
[0104] Catalyst compositions comprising various relative amounts of
oxides of Ni, Nb, Ta and Ti were prepared in small (.about.100 mg)
quantities by precipitation substantially as described in
connection with Example 1. Table 2A summarizes the composition and
amounts of the various catalyst compositions.
[0105] In a first set of experiments, the dried catalyst
compositions were calcined to 300.degree. C. in an atmosphere of
air with an oven temperature profile: ramp to 300.degree. C. at
2.degree. C./min and dwell at 300.degree. C. for 8 hours. The mixed
metal oxide catalysts (.about.50 mg) were screened in the fixed bed
parallel reactor. The performance characteristics of these
catalysts for ethane oxidative dehydrogenation at 300.degree. C.
with relative flowrates of ethane:nitrogen:oxygen of
0.42:0.54:0.088 sccm are summarized in Table 2B (ethane conversion)
and Table 2C (ethylene selectivity). The catalysts were also
screened for ethane oxidative dehydrogenation at 300.degree. C.
with relative flowrates of ethane:nitrogen:oxygen of
0.42:0.82:0.022 sccm. The performance characteristics for these
experiments are summarized in Table 2D (ethane conversion) and
Table 2E (ethylene selectivity).
[0106] After these screenings, these catalyst were subsequently
recalcined to 400.degree. C. for 8 hours with a similar temperature
profile. The performance characteristics of these catalysts for
ethane oxidative dehydrogenation in the parallel fixed bed reactor
at 300.degree. C. with relative flowrates of ethane:nitrogen:oxygen
of 0.42:0.54:0.088 sccm are summarized in Table 2F (ethane
conversion) and Table 2G (ethylene selectivity). The recalcined
catalysts were also screened for ethane oxidative dehydrogenation
at 300.degree. C. with relative flowrates of ethane:nitrogen:oxygen
of 0.42:0.82:0.022 sccm. The performance characteristics for these
experiments are summarized in Table 2H (ethane conversion) and
Table 2I (ethylene selectivity).
9TABLE 2A Catalyst composition (mole fraction) and sample mass, "m"
(mg) of bulk NiNbTaTi Oxide Mixtures Col Row 1 2 3 4 5 6 1 Ni
0.6014 0.5714 0.5418 0.5124 0.4832 0.4542 Nb 0.1065 0.1188 0.1310
0.1431 0.1550 0.1669 Ta 0.0948 0.1133 0.1317 0.1498 0.1679 0.1857
Ti 0.1973 0.1964 0.1956 0.1948 0.1939 0.1931 m 50.0 50.0 50.3 50.5
49.5 50.5 2 Ni 0.4889 0.4730 0.4559 0.4375 0.4176 0.3959 Nb 0.0808
0.1089 0.1392 0.1718 0.2071 0.2454 Ta 0.2699 0.2518 0.2323 0.2113
0.1886 0.1639 Ti 0.1604 0.1662 0.1726 0.1794 0.1868 0.1948 m 49.5
50.6 50.0 50.5 49.6 49.4 3 Ni 0.6004 0.5731 0.5448 0.5154 0.4849
0.4532 Nb 0.1163 0.1279 0.1399 0.1524 0.1654 0.1788 Ta 0.1295
0.1424 0.1557 0.1696 0.1840 0.1990 Ti 0.1538 0.1566 0.1595 0.1626
0.1657 0.1689 m 49.9 49.3 49.5 49.6 49.7 50.0 4 Ni 0.6435 0.6135
0.5835 0.5535 0.5234 0.4934 Nb 0.1173 0.1315 0.1457 0.1598 0.1740
0.1882 Ta 0.1306 0.1463 0.1621 0.1779 0.1937 0.2095 Ti 0.1086
0.1087 0.1087 0.1088 0.1089 0.1089 m 49.5 49.3 49.6 49.5 50.1
50.3
[0107]
10TABLE 2B Ethane conversion for the catalysts in Table 2A. Test
conditions: 300.degree. C. with ethane/nitrogen/oxygen flow of
0.42/0.54/0.088 sccm. Ethane Conversion (%) of Ni--Nb--Ta--Ti Oxide
Mixtures 1 2 3 4 5. 6 1 10.7 17.0 18.1 19.4 19.2 13.6 2 9.0 17.5
18.7 16.8 19.0 15.6 3 12.1 17.5 19.0 19.0 19.1 16.8 4 7.8 16.8 19.5
18.8 17.7 18.2
[0108]
11TABLE 2C Ethylene selectivity for the catalysts in Table 2A. Test
conditions: 300.degree. C. with ethane/nitrogen/oxygen flow of
0.42/0.54/0.088 sccm. Ethylene Selectivity (%) of Ni--Nb--Ta--Ti
Oxide Mixtures 1 2 3 4 5 6 1 82.9 83.1 84.3 85.1 84.2 83.2 2 80.4
86.6 85.1 84.7 84.5 84.1 3 70.9 84.4 84.9 84.7 84.6 84.0 4 76.9
84.7 84.8 84.5 84.8 85.0
[0109]
12TABLE 2D Ethane conversion for the catalysts in Table 2A. Test
conditions: 300.degree. C. with ethane/nitrogen/oxygen flow of
0.42/0.082/0.022 sccm. Ethane Conversion (%) of Ni--Nb--Ta--Ti
Oxide Mixtures 1 2 3 4 5 6 1 10.5 11.2 11.4 11.9 11.8 11.0 2 8.2
11.4 11.8 11.3 11.9 11.5 3 9.3 11.6 11.3 11.6 11.8 11.3 4 7.1 11.6
12.0 11.6 11.7 11.4
[0110]
13TABLE 2E Ethylene selectivity for the catalysts in Table 2A. Test
conditions: 300.degree. C. with ethane/nitrogen/oxygen flow of
0.42/0.082/0.022 sccm. Ethylene Selectivity (%) of Ni--Nb--Ta--Ti
Oxide Mixtures 1 2 3 4 5. 6 1 91.6 92.7 92.9 93.5 92.9 92.5 2 90.1
93.4 93.3 93.4 93.2 92.6 3 86.7 93.0 93.5 93.3 93.3 92.7 4 87.7
93.4 93.4 93.0 93.2 92.9
[0111]
14TABLE 2F Ethane conversion for the catalysts in Table 2A. Test
conditions: 300.degree. C. with ethane/nitrogen/oxygen flow of
0.42/0.54/0.088 sccm. Ethane Conversion (%) of Ni--Nb--Ta--Ti Oxide
Mixtures 1 2 3 4 5 6 1 5.6 12.3 13.2 14.1 14.6 7.1 2 4.9 14.7 13.5
11.4 15.0 8.7 3 8.1 12.6 13.3 14.6 14.6 11.1 4 3.7 10.4 14.3 14.8
14.8 14.4
[0112]
15TABLE 2G Ethylene selectivity for the catalysts in Table 2A. Test
conditions: 300.degree. C. with ethane/nitrogen/oxygen flow of
0.42/0.54/0.088 sccm. Ethylene Selectivity (%) of Ni--Nb--Ta--Ti
Oxide Mixtures 1 2 3 4 5 6 1 83.4 80.9 82.1 84.1 83.8 84.9 2 81.6
83.9 84.3 84.5 83.6 85.1 3 67.9 83.5 83.7 83.6 83.6 84.5 4 78.5
84.7 83.8 83.2 83.6 84.5
[0113]
16TABLE 2H Ethane conversion for the catalysts in Table 2A. Test
conditions: 300.degree. C. with ethane/nitrogen/oxygen flow of
0.42/0.082/0.022 sccm. Ethane Conversion (%) of Ni--Nb--Ta--Ti
Oxide Mixtures 1 2 3 4 5. 6 1 5.7 10.7 8.4 11.5 11.9 7.6 2 5.3 10.2
11.1 10.7 11.7 8.6 3 8.4 11.3 11.2 11.5 11.8 10.6 4 4.1 10.1 11.7
11.6 11.3 11.2
[0114]
17TABLE 2I Ethylene selectivity for the catalysts in Table 2A. Test
conditions: 300.degree. C. with ethane/nitrogen/oxygen flow of
0.42/0.082/0.022 sccm. Ethylene Selectivity (%) of Ni--Nb--Ta--Ti
Oxide Mixtures 1 2 3 4 5 6 1 88.9 92.1 92.4 93.2 92.8 90.9 2 87.4
93.2 93.1 93.0 93.2 91.7 3 85.7 92.5 93.0 93.2 93.0 92.3 4 85.5
92.6 93.1 92.9 93.1 92.9
Example 3
ODHE Over NiNbZr/NiTaZr Oxide Catalysts. (#14840/15157)
[0115] Catalysts were prepared in small quantities (.about.100 mg)
from nickel nitrate ([Ni]=1.0 M), niobium oxalate ([Nb]=0.569 M),
tantalum oxalate ([Ta]=0.650 M), and zirconium oxalate ([Zr]=0.36
M) aqueous stock solutions by precipitation with tetraethylammonium
hydroxide. The solid materials were separated from solution by
centrifugation. The supernatant was decanted and solid materials
were dried at 60.degree. C. under a reduced atmosphere. Table 3A
summarizes the composition and amounts of the various catalyst
compositions.
[0116] In a first set of experiments, the dried catalyst
compositions were calcined to 300.degree. C. in an atmosphere of
air with an oven temperature profile: ramp to 300.degree. C. at
2.degree. C./min and dwell at 300.degree. C. for 8 hours. The mixed
metal oxide catalysts (.about.50 mg) were screened in the fixed bed
parallel reactor. The performance characteristics of these
catalysts for ethane oxidative dehydrogenation at 300.degree. C.
with relative flowrates of ethane:nitrogen:oxygen of
0.42:0.54:0.088 sccm are summarized in Table 3B (ethane conversion)
and Table 3C (ethylene selectivity).
[0117] After initial screening, these catalyst were subsequently
recalcined to 400.degree. C. with a similar temperature profile.
The performance characteristics of these catalysts for ethane
oxidative dehydrogenation in the parallel fixed bed reactor at
300.degree. C. with relative flowrates of ethane:nitrogen:oxygen of
0.42:0.54:0.088 sccm are summarized in Table 3D (ethane conversion)
and Table 3E (ethylene selectivity).
18TABLE 3A Catalyst composition (mole fraction) of Ni--Nb--Zr and
Ni--Ta--Zr oxide mixtures & sample mass, "m" (mg) used in
parallel fixed bed reactor screen. Col Row 1 2 3 4 5 6 1 Ni 1.0000
0.8969 0.7944 0.6927 0.5917 0.4914 Nb 0.0000 0.0000 0.0000 0.0000
0.0000 0.0000 Ta 0.0000 0.1031 0.2056 0.3073 0.4083 0.5086 Zr
0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 m 49.8 49.5 49.6 49.6
50.1 49.5 2 Ni 0.9119 0.9328 0.8262 0.7203 0.6152 0.5108 Nb 0.0881
0.0000 0.0000 0.0000 0.0000 0.0000 Ta 0.0000 0.0000 0.1069 0.2130
0.3184 0.4230 Zr 0.0000 0.0672 0.0669 0.0667 0.0664 0.0662 m 49.3
49.6 50.4 49.9 50.3 49.3 3 Ni 0.8214 0.8405 0.8606 0.7502 0.6406
0.5319 Nb 0.1786 0.0914 0.0000 0.0000 0.0000 0.0000 Ta 0.0000
0.0000 0.0000 0.1109 0.2210 0.3303 Zr 0.0000 0.0681 0.1394 0.1389
0.1384 0.1379 m 49.8 50.6 50.5 49.5 50.6 49.9 4 Ni 0.7284 0.7456
0.7637 0.7826 0.6682 0.5547 Nb 0.2716 0.1853 0.0949 0:0000 0.0000
0.0000 Ta 0.0000 0.0000 0.0000 0.0000 0.1153 0.2296 Zr 0.0000
0.0690 0.1414 0.2174 0.2165 0.2157 m 50.1 49.4 49.5 49.6 49.5 50.6
5 Ni 0.6329 0.6481 0.6640 0.6807 0.6983 0.5796 Nb 0.3671 0.2819
0.1926 0.0987 0.0000 0.0000 Ta 0.0000 0.0000 0.0000 0.0000 0.0000
0.1200 Zr 0.0000 0.0700 0.1434 0.2206 0.3017 0.3005 m 50.3 49.6
49.8 49.5 49.9 49.7 6 Ni 0.5348 0.5478 0.5614 0.5758 0.5909 0.6068
Nb 0.4652 0.3812 0.2931 0.2004 0.1028 0.0000 Ta 0.0000 0.0000
0.0000 0.0000 0.0000 0.0000 Zr 0.0000 0.0710 0.1455 0.2239 0.3063
0.3932 m 50.0 49.8 50.3 50.6 50.0 49.9
[0118]
19TABLE 3B Ethane conversion for the catalysts in Table 3A. Test
conditions: 300.degree. C. with ethane/nitrogen/oxygen flow of
0.42/0.54/0.088 sccm. Ethane Conversion (%) of Ni--Nb--Ta--Zr Oxide
Mixtures 1 2 3 4 5 6 1 9.1 18.2 18.9 19.2 18.6 15.7 2 16.0 14.8
18.0 16.4 17.3 19.5 3 18.4 18.1 15.4 17.6 13.1 16.7 4 19.3 19.1
16.7 14.7 15.2 15.3 5 19.4 19.0 13.7 15.3 13.6 16.1 6 18.9 19.0
12.1 11.3 12.7 12.4
[0119]
20TABLE 3C Ethylene Selectivity for the catalysts in Table 3A. Test
conditions: 300.degree. C. with ethane/nitrogen/oxygen flow of
0.42/0.54/0.088 sccm. Ethylene Selectivity (%) of Ni--Nb--Ta--Zr
Oxide Mixtures 1 2 3 4 5 6 1 46.0 83.8 84.4 84.0 84.8 83.0 2 80.4
74.4 83.4 81.1 80.7 83.6 3 84.8 83.7 77.2 81.8 73.9 81.5 4 84.4
84.2 79.5 76.6 73.6 79.1 5 84.7 82.9 73.4 76.6 73.4 79.3 6 82.7
84.6 73.9 70.2 73.9 76.5
[0120]
21TABLE 3D Ethane Conversion for the catalysts in Table 3A but
recalcined to 400.degree. C. Test conditions: 300.degree. C. with
ethane/nitrogen/oxygen flow of 0.42/0.54/0.088 sccm. Ethane
Conversion (%) of Ni--Nb--Ta--Zr Oxide Mixtures 1 2 3 4 5 6 1 6.3
12.2 12.6 12.5 11.9 8.9 2 9.1 10.8 12.2 10.8 11.4 15.1 3 12.2 13.8
10.2 11.9 8.0 11.2 4 13.2 13.2 11.4 8.8 10.3 10.8 5 13.6 13.5 8.6
11.2 9.2 12.2 6 14.7 13.4 7.5 6.4 8.0 7.5
[0121]
22TABLE 3E Ethylene Selectivity for the catalysts in Table 3A but
recalcined to 400.degree. C. Test conditions: 300.degree. C. with
ethane/nitrogen/oxygen flow of 0.42/0.54/0.088 sccm. Ethylene
Selectivity (%) of Ni--Nb--Ta--Zr Oxide Mixtures 1 2 3 4 5 6 1 33.4
83.3 85.4 84.6 86.0 86.7 2 78.8 66.2 83.3 81.0 80.9 83.5 3 86.4
84.1 70.6 80.2 72.9 81.1 4 85.8 84.8 78.6 69.1 69.3 78.5 5 86.5
83.7 71.9 75.8 69.7 77.0 6 80.4 82.9 72.3 62.9 71.7 74.9
Example 4
ODHE Over NiTiZr Oxide Catalysts. (#14332)
[0122] Catalysts were prepared in small quantities (.about.100 mg)
from nickel nitrate ([Ni]=1.0 M), titanium oxalate ([Ti]=0.713 M)
and zirconium oxalate ([Zr]=0.36 M) aqueous stock solutions by
precipitation with tetramethylammonium hydroxide. The solid
materials were separated from solution by centrifugation. The
supernatant was decanted and solid materials were dried at
60.degree. C. under a reduced atmosphere. Table 4A summarizes the
composition and amounts of the various catalyst compositions.
[0123] In a first set of experiments, the dried catalyst
compositions were calcined to 300.degree. C. in an atmosphere of
air with an oven temperature profile: ramp to 300.degree. C. at
2.degree. C./min and dwell at 300.degree. C. for 8 hours. The mixed
metal oxide catalysts (.about.50 mg) were screened in the fixed bed
parallel reactor. The performance characteristics of these
catalysts for ethane oxidative dehydrogenation at 300.degree. C.
with relative flowrates of ethane:nitrogen:oxygen of
0.42:0.54:0.088 sccm are summarized in Table 4B (ethane conversion)
and Table 4C (ethylene selectivity).
23TABLE 4A Catalyst composition (mole fraction) of NiTiZr oxide
catalysts and sample mass (mg) used in parallel fixed bed reactor
screen. Column Row 1 2 3 4 5 6 1 Ni 1.000 Zr 0.000 Ti 0.000 mass
54.1 (mg) 2 Ni 0.930 0.913 Zr 0.070 0.000 Ti 0.000 0.087 mass 52.3
47.6 (mg) 3 Ni 0.862 0.847 0.833 Zr 0.138 0.068 0.000 Ti 0.000
0.085 0.167 mass 54.8 50.3 52.3 (mg) 4 Ni 0.797 0.784 0.771 0.759
Zr 0.203 0.133 0.065 0.000 Ti 0.000 0.083 0.163 0.241 mass 52.0
54.0 47.4 50.2 (mg) 5 Ni 0.735 0.723 0.712 0.701 0.690 Zr 0.265
0.195 0.128 0.063 0.000 Ti 0.000 0.081 0.160 0.236 0.310 mass 52.0
52.9 45.3 46.4 49.6 (mg) 6 Ni 0.676 0.665 0.654 0.644 0.635 0.625
Zr 0.324 0.255 0.188 0.124 0.061 0.000 Ti 0.000 0.080 0.157 0.232
0.305 0.375 mass 53.0 45.2 50.6 47.3 51.8 52.5 (mg)
[0124]
24TABLE 4B Ethane conversion for catalysts in Table 4A. Test
conditions: 300.degree. C. with ethane:nitrogen:oxygen flow of
0.42:0.54:0.088 sccm. 1 2 3 4 5 6 1 7.9 2 15.5 14.9 3 17.0 16.5
16.6 4 13.3 14.3 17.2 17.3 5 14.2 15.4 15.8 17.7 20.6 6 12.4 14.9
13.0 13.5 16.1 19.1
[0125]
25TABLE 4C Ethylene selectivity for catalysts in Table 4A. Test
conditions: 300.degree. C. with ethane:nitrogen:oxygen flow of
0.42:0.54:0.088 sccm. 1 2 3 4 5 6 1 46.1 2 72.9 78.5 3 75.8 76.5
81.9 4 71.3 78.8 81.0 81.7 5 71.0 74.8 72.1 81.2 84.7 6 69.0 71.3
76.8 70.9 77.7 83.2
Example 5
ODHE Over NiTiCe/NiZrCe Oxide Catalysts. (#14841/15158)
[0126] Ni--Ti--Ce and Ni--Zr--Ce oxide catalysts were prepared and
screened in a manner similar to the catalysts in Examples 1 and 3,
using cerium nitrate ([Ce]=1.00 M) aqueous stock solution. Table 5A
summarizes the composition and amounts of the various catalyst
compositions.
[0127] In the initial screening (calcination at 300.degree. C., 8
hours, screening in fixed bed parallel reactor at 300.degree. C.
with flowrates of ethane:nitrogen:oxygen of 0.42:0.54:0.088 sccm,
as described), ethane conversion values for the NiTiCe oxide
compositions ranged from 9.6 % (with ethylene selectivity of 66.5%)
to 17.6% (with ethylene selectivity of 73.3%), and ethylene
selectivity values ranged from 66.5% (with ethane conversion of
9.6%) to 80.1% (with ethane conversion of 17.0%). Ethane conversion
values for the NiZrCe oxide compositions ranged from 13.4% (with
ethylene selectivity of 69.1%) to 16.4% (with ethylene selectivity
of 75.9%), and ethylene selectivity values ranged from 69.1% (with
ethane conversion of 13.4%) to 78.2% (with ethane conversion of
15.4%).
[0128] After recalcining (400.degree. C., 8 hours, as described),
the catalysts were rescreened (results not shown).
26TABLE 5A Catalyst composition (mole fraction) of Ni--Ti--Ce and
Ni--Zr--Ce oxide catalysts and sample mass, "m" (mg) used in
parallel fixed bed reactor screen. Col Row 1 2 3 4 5 6 1 Ni 1.0000
0.9259 0.8475 0.7642 0.6757 0.5814 Ti 0.0000 0.0000 0.0000 0.0000
0.0000 0.0000 Ce 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 Zr
0.0000 0.0741 0.1525 0.2358 0.3243 0.4186 m 49.5 49.4 49.7 48.6
49.2 49.8 2 Ni 0.9091 0.9474 0.8677 0.7830 0.6928 0.5967 Ti 0.0909
0.0000 0.0000 0.0000 0.0000 0.0000 Ce 0.0000 0.0526 0.0542 0.0559
0.0577 0.0597 Zr 0.0000 0.0000 0.0781 0.1611 0.2494 0.3437 m 50.6
50.7 49.5 50.0 49.7 50.6 3 Ni 0.8163 0.8511 0.8889 0.8028 0.7109
0.6127 Ti 0.1837 0.0957 0.0000 0.0000 0.0000 0.0000 Ce 0.0000
0.0532 0.1111 0.1147 0.1185 0.1225 Zr 0.0000 0.0000 0.0000 0.0826
0.1706 0.2647 m 49.4 49.7 50.5 49.7 49.4 50.3 4 Ni 0.7216 0.7527
0.7865 0.8235 0.7299 0.6297 Ti 0.2784 0.1935 0.1011 0.0000 0.0000
0.0000 Ce 0.0000 0.0538 0.1124 0.1765 0.1825 0.1889 Zr 0.0000
0.0000 0.0000 0.0000 0.0876 0.1814 m 49.9 50.6 50.4 49.3 50.0 50.0
5 Ni 0.6250 0.6522 0.6818 0.7143 0.7500 0.6477 Ti 0.3750 0.2935
0.2045 0.1071 0.0000 0.0000 Ce 0.0000 0.0543 0.1136 0.1786 0.2500
0.2591 Zr 0.0000 0.0000 0.0000 0.0000 0.0000 0.0933 m 49.7 49.6
49.9 50.6 50.1 50.4 6 Ni 0.5263 0.5495 0.5747 0.6024 0.6329 0.6667
Ti 0.4737 0.3956 0.3103 0.2169 0.1139 0.0000 Ce 0.0000 0.0549
0.1149 0.1807 0.2532 0.3333 Zr 0.0000 0.0000 0.0000 0.0000 0.0000
0.0000 m 50.0 49.6 49.9 50.0 50.1 50.4
Example 6
ODHE Over NiTiSb/NiZrSb Oxide Catalysts. (#14842/15159)
[0129] Ni--Ti--Sb and Ni--Zr--Sb oxide catalysts were prepared and
screened in a manner similar to the catalysts in Examples 1 and 3,
using antimony acetate ([Sb]=0.234 M) aqueous stock solution. Table
6A summarizes the composition and amounts of the various catalyst
compositions.
[0130] In the initial screening (calcination at 300.degree. C., 8
hours, screening in fixed bed parallel reactor at 300.degree. C.
with flowrates of ethane:nitrogen:oxygen of 0.42:0.54:0.088 sccm,
as described), ethane conversion values for the NiTiSb oxide
compositions ranged from 1.0% (with ethylene selectivity of 73.3%)
to 15.8% (with ethylene selectivity of 79.2%), and ethylene
selectivity values ranged from 73.3% (with ethane conversion of
1.0%) to 81.8% (with ethane conversion of 7.2%). Ethane conversion
values for the NiZrSb oxide compositions ranged from 1.4% (with
ethylene selectivity of 75.5%) to 11.9% (with ethylene selectivity
of 74.7%), and ethylene selectivity values ranged from 63.2% (with
ethane conversion of 6.3%) to 78.3% (with ethane conversion of
11.3%).
[0131] After recalcining (400.degree. C., 8 hours, as described),
the catalysts were rescreened (results not shiown).
27TABLE 6A Catalyst composition (mole fraction) of NiTiSb/NiZrSb
oxide mixtures and sample mass, "m" (mg) used in parallel fixed bed
reactor screen. Col Row 1 2 3 4 5 6 1 Ni 1.0000 0.9377 0.8642
0.7764 0.6695 0.5365 Ti 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000
Zr 0.0000 0.0623 0.1358 0.2236 0.3305 0.4635 Sb 0.0000 0.0000
0.0000 0.0000 0.0000 0.0000 m 49.4 50.6 50.4 50.6 49.3 49.5 2 Ni
0.9233 0.9403 0.8669 0.7790 0.6719 0.5387 Ti 0.0767 0.0000 0.0000
0.0000 0.0000 0.0000 Zr 0.0000 0.0000 0.0681 0.1496 0.2488 0.3724
Sb 0.0000 0.0597 0.0651 0.0715 0.0793 0.0890 m 50.4 50.7 50.0 49.4
50.0 50.2 3 Ni 0.8359 0.8523 0.8695 0.7816 0.6744 0.5409 Ti 0.1641
0.0837 0.0000 0.0000 0.0000 0.0000 Zr 0.0000 0.0000 0.0000 0.0750
0.1665 0.2804 Sb 0.0000 0.0640 0.1305 0.1434 0.1591 0.1786 m 50.4
50.4 49.2 50.3 49.4 49.7 4 Ni 0.7353 0.7509 0.7672 0.7842 0.6769
0.5432 Ti 0.2647 0.1802 0.0921 0.0000 0.0000 0.0000 Zr 0.0000
0.0000 0.0000 0.0000 0.0836 0.1877 Sb 0.0000 0.0689 0.1408 0.2158
0.2395 0.2691 m 49.2 49.3 49.8 50.7 50.6 49.8 5 Ni 0.6184 0.6326
0.6475 0.6631 0.6795 0.5455 Ti 0.3816 0.2928 0.1998 0.1023 0.0000
0.0000 Zr 0.0000 0.0000 0.0000 0.0000 0.0000 0.0943 Sb 0.0000
0.0746 0.1527 0.2346 0.3205 0.3603 m 50.8 49.5 49.3 50.0 50.2 49.7
6 Ni 0.4808 0.4928 0.5055 0.5188 0.5329 0.5478 Ti 0.5192 0.4258
0.3276 0.2241 0.1151 0.0000 Zr 0.0000 0.0000 0.0000 0.0000 0.0000
0.0000 Sb 0.0000 0.0814 0.1669 0.2570 0.3520 0.4522 m 20.2 50.6
50.5 50.8 50.4 49.0
Example 7
ODHE Over NiTiNd/NiZrNd Oxide Catalysts. (#15154/15420)
[0132] Ni--Ti--Nd and Ni--Zr--Nd oxide catalysts were prepared and
screened in a manner similar to the catalysts in Examples 1 and 3,
using neodymium nitrate ([Nd]=0.50 M) aqueous stock solution. Table
7A summarizes the composition and amounts of the various catalyst
compositions.
[0133] In the initial screening (calcination at 300.degree. C., 8
hours, screening in fixed bed parallel reactor at 300.degree. C.
with flowrates of ethane:nitrogen:oxygen of 0.42:0.54:0.088 sccm,
as described), ethane conversion (C) and ethylene selectivity (S)
values for the NiTiNd oxide compositions ranged from 6.3% C, 45.1%
S to 18.1% C, 84.6% S. Ethane conversion values for the NiZrNd
oxide compositions ranged from 4.5% (with ethylene selectivity of
41.5%) to 13.4% (with ethylene selectivity of 71.8%), and ethylene
selectivity values ranged from 41.5% (with ethane conversion of
4.5%) to 77.3% (with ethane conversion of 13.1%).
[0134] In a second screening in the fixed bed parallel reactor at
300.degree. C. with different flowrates (ethane:nitrogen:oxygen of
0.42:0.082:0.022 sccm), ethane conversion (C) and ethylene
selectivity (S) values for the NiTiNd oxide compositions ranged
from 4.9% C, 62.7% S to 11.0% C, 93.3% S. Ethane conversion (C) and
ethylene selectivity (S) values for the NiZrNd oxide compositions
ranged from 4.2% C, 59.0% S to 10.0% C, 90.7% S.
[0135] After recalcining (400.degree. C., 8 hours, as described),
the catalysts were rescreened (results not shown).
28TABLE 7A Catalyst composition (mole fraction) of NiTiNd/NiZrNd
oxide catalysts and sample mass, "m" (mg) used in parallel fixed
bed reactor screen. Col Row 1 2 3 4 5 6 1 Ni 1.0000 0.9259 0.8475
0.7642 0.6757 0.5814 Ti 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000
Zr 0.0000 0.0741 0.1525 0.2358 0.3243 0.4186 Nd 0.0000 0.0000
0.0000 0.0000 0.0000 0.0000 m 49.6 49.7 49.5 49.3 50.3 49.5 2 Ni
0.9259 0.9474 0.8677 0.7830 0.6928 0.5967 Ti 0.0741 0.0000 0.0000
0.0000 0.0000 0.0000 Zr 0.0000 0.0000 0.0781 0.1611 0.2494 0.3437
Nd 0.0000 0.0526 0.0542 0.0559 0.0577 0.0597 m 49.9 50.8 50.4 49.4
49.4 50.0 3 Ni 0.8475 0.8677 0.8889 0.8028 0.7109 0.6127 Ti 0.1525
0.0781 0.0000 0.0000 0.0000 0.0000 Zr 0.0000 0.0000 0.0000 0.0826
0.1706 0.2647 Nd 0.0000 0.0542 0.1111 0.1147 0.1185 0.1225 m 49.9
49.2 49.4 50.3 49.7 49.4 4 Ni 0.7642 0.7830 0.8028 0.8235 0.7299
0.6297 Ti 0.2358 0.1611 0.0826 0.0000 0.0000 0.0000 Zr 0.0000
0.0000 0.0000 0.0000 0.0876 0.1814 Nd 0.0000 0.0559 0.1147 0.1765
0.1825 0.1889 m 49.8 49.5 50.0 49.8 49.8 49.8 5 Ni 0.6757 0.6928
0.7109 0.7299 0.7500 0.6477 Ti 0.3243 0.2494 0.1706 0.0876 0.0000
0.0000 Zr 0.0000 0.0000 0.0000 0.0000 0.0000 0.0933 Nd 0.0000
0.0577 0.1185 0.1825 0.2500 0.2591 m 49.5 49.6 49.8 50.0 49.4 50.1
6 Ni 0.5814 0.5967 0.6127 0.6297 0.6477 0.6667 Ti 0.4186 0.3437
0.2647 0.1814 0.0933 0.0000 Zr 0.0000 0.0000 0.0000 0.0000 0.0000
0.0000 Nd 0.0000 0.0597 0.1225 0.1889 0.2591 0.3333 m 50.1 49.3
49.5 50.7 50.6 45.0
Example 8
ODHE Over NiTiYb/NiZrYb Oxide Catalysts. (#15155/15421)
[0136] Ni--Ti--Yb and Ni--Zr--Yb oxide catalysts were prepared and
screened in a manner similar to the catalysts in Examples 1 and 3,
using ytterbium nitrate ([Yb]=0.456 M) aqueous stock solution.
Table 8A summarizes the composition and amounts of the various
catalyst compositions.
[0137] In the initial screening (calcination at 300.degree. C., 8
hours, screening in fixed bed parallel reactor at 300.degree. C.
with flowrates of ethane:nitrogen:oxygen of 0.42:0.54:0.088 sccm,
as described), ethane conversion (C) and ethylene selectivity (S)
values for the NiTiYb oxide compositions ranged from 4.1% C, 41.6%
S to 16.8% C, 83.4% S. Ethane conversion (C) and ethylene
selectivity (S) values for the NiZrYb oxide compositions ranged
from 5.0% C, 46.8% S to 13.2% C, 75.6% S.
[0138] In a second screening in the fixed bed parallel reactor at
300.degree. C. with different flonvrates (ethane:nitrogen:oxygen of
0.42:0.082:0.022 sccm), ethane conversion (C) and ethylene
selectivity (S) values for the NiTiYb oxide compositions ranged
from 6.0% C, 72.9% S to 10.6% C, 91.8% S. Ethane conversion (C) and
ethylene selectivity (S) values for the NiZrYb oxide compositions
ranged from 6.7% C, 75.9% S to 10.3% C, 89.9% S.
[0139] After recalcining (400.degree. C., 8 hours, as described),
the catalysts were rescreened (results not shown).
29TABLE 8A Catalyst composition (mole fraction) of NiTiYb/NiZrYb
oxide catalysts and sample mass, "m" (mg) used in parallel fixed
bed reactor screen. Col Row 1 2 3 4 5 6 1 Ni 1.0000 0.9259 0.8475
0.7642 0.6757 0.5814 Ti 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000
Zr 0.0000 0.0741 0.1525 0.2358 0.3243 0.4186 Yb 0.0000 0.0000
0.0000 0.0000 0.0000 0.0000 m 50.0 -- -- -- -- -- 2 Ni 0.9091
0.9518 0.8718 0.7869 0.6964 0.5998 Ti 0.0909 0.0000 0.0000 0.0000
0.0000 0.0000 Zr 0.0000 0.0000 0.0785 0.1619 0.2507 0.3455 Yb
0.0000 0.0482 0.0497 0.0513 0.0529 0.0547 m 49.3 49.6 50.1 50.0
49.4 50.3 3 Ni 0.8163 0.8551 0.8977 0.8109 0.7184 0.6194 Ti 0.1837
0.0962 0.0000 0.0000 0.0000 0.0000 Zr 0.0000 0.0000 0.0000 0.0834
0.1724 0.2676 Yb 0.0000 0.0487 0.1023 0.1057 0.1092 0.1130 m 49.7
49.3 49.8 50.0 49.5 49.1 4 Ni 0.7216 0.7563 0.7944 0.8365 0.7418
0.6404 Ti 0.2784 0.1945 0.1021 0.0000 0.0000 0.0000 Zr 0.0000
0.0000 0.0000 0.0000 0.0890 0.1844 Yb 0.0000 0.0493 0.1035 0.1635
0.1691 0.1752 m 49.5 50.3 49.3 49.8 50.2 50.6 5 Ni 0.6250 0.6553
0.6887 0.7257 0.7669 0.6628 Ti 0.3750 0.2949 0.2066 0.1089 0.0000
0.0000 Zr 0.0000 0.0000 0.0000 0.0000 0.0000 0.0954 Yb 0.0000
0.0498 0.1047 0.1655 0.2331 0.2418 m 49.3 49.9 50.0 49.5 50.6 49.8
6 Ni 0.5263 0.5521 0.5806 0.6121 0.6473 0.6868 Ti 0.4737 0.3975
0.3135 0.2204 0.1165 0.0000 Zr 0.0000 0.0000 0.0000 0.0000 0.0000
0.0000 Yb 0.0000 0.0504 0.1059 0.1675 0.2361 0.3132 m 49.4 49.6
50.3 49.6 50.5 49.8
Example 9
ODHE Over NiTiSm/NiZrSm Oxide Catalysts. (#15935/16221)
[0140] Ni--Ti--Sm and Ni--Zr--Sm oxide catalysts were prepared and
screened in a manmer similar to the catalysts in Examples 1 and 3,
using samarium nitrate ([Sm]=0.506 M) aqueous stock solution. Table
9A summarizes the composition and amounts of the various catalyst
compositions.
[0141] In the initial screening (calcination at 300.degree. C., 8
hours, screening in fixed bed parallel reactor at 300.degree. C.
with flowrates of ethane:nitrogen:oxygen of 0.42:0.54:0.088 sccm,
as described), ethane conversion values for the NiTiSm oxide
compositions ranged from 10.4% (with ethylene selectivity of 57.5%)
to 19.0% (with ethylene selectivity of 81.8%), and ethylene
selectivity values ranged from 57.5% (with ethane conversion of
10.4%) to 82.8% (with ethane conversion of 18.3%). Ethane
conversion values for the NiZrSm oxide compositions ranged from
11.5% (with ethylene selectivity of 60.7%) to 13.7% (with ethylene
selectivity of 71.0%), and ethylene selectivity values ranged from
60.7% (with ethane conversion of 11.5%) to 76.7% (with ethane
conversion of 13.4%).
[0142] In a second screening in the fixed bed parallel reactor at
300.degree. C. with different flowrates (ethane:nitrogen:oxygen of
0.42:0.082:0.022 sccm), ethane conversion values for the NiTiSm
oxide compositions ranged from 6.8% (with ethylene selectivity of
75.1%) to 11.5% (with ethylene selectivity of 92.2%), and ethylene
selectivity values ranged from 75.1% (with ethane conversion of
6.8%) to 92.7% (with ethane conversion of 11.3%). Ethane conversion
(C) and ethylene selectivity (S) values for the NiZrSm oxide
compositions ranged from 7.7% C, 80.3% S to 10.3% C, 90.4% S.
[0143] After recalcining (400.degree. C., 8 hours, as described),
the catalysts were rescreened (results not shown).
30TABLE 9A Catalyst composition (mole fraction) of NiTiSm/NiZrSm
oxide catalysts and sample mass, "m" (mg) used in parallel fixed
bed reactor screen. Col Row 1 2 3 4 5 6 1 Ni 1.0000 0.9259 0.8475
0.7642 0.6757 0.5814 Ti 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000
Zr 0.0000 0.0741 0.1525 0.2358 0.3243 0.4186 Sm 0.0000 0.0000
0.0000 0.0000 0.0000 0.0000 m 49.6 49.8 50.0 50.5 50.3 50.0 2 Ni
0.9091 0.9730 0.8919 0.8055 0.7134 0.6150 Ti 0.0909 0.0000 0.0000
0.0000 0.0000 0.0000 Zr 0.0000 0.0000 0.0803 0.1657 0.2568 0.3542
Sm 0.0000 0.0270 0.0279 0.0288 0.0297 0.0308 m 49.8 50.8 49.5 49.7
50.3 49.7 3 Ni 0.8163 0.8743 0.9412 0.8516 0.7557 0.6527 Ti 0.1837
0.0984 0.0000 0.0000 0.0000 0.0000 Zr 0.0000 0.0000 0.0000 0.0876
0.1814 0.2820 Sm 0.0000 0.0273 0.0588 0.0608 0.0630 0.0653 m 49.5
50.4 49.7 50.1 50.3 49.9 4 Ni 0.7216 0.7735 0.8333 0.9032 0.8032
0.6954 Ti 0.2784 0.1989 0.1071 0.0000 0.0000 0.0000 Zr 0.0000
0.0000 0.0000 0.0000 0.0964 0.2003 Sm 0.0000 0.0276 0.0595 0.0968
0.1004 0.1043 m 49.5 49.5 50.7 -- 49.5 50.7 5 Ni 0.6250 0.6704
0.7229 0.7843 0.8571 0.7440 Ti 0.3750 0.3017 0.2169 0.1176 0.0000
0.0000 Zr 0.0000 0.0000 0.0000 0.0000 0.0000 0.1071 Sm 0.0000
0.0279 0.0602 0.0980 0.1429 0.1488 m 50.6 49.6 49.8 48.6 50.7 48.8
6 Ni 0.5263 0.5650 0.6098 0.6623 0.7246 0.8000 Ti 0.4737 0.4068
0.3293 0.2384 0.1304 0.0000 Zr 0.0000 0.0000 0.0000 0.0000 0.0000
0.0000 Sm 0.0000 0.0282 0.0610 0.0993 0.1449 0.2000 m 50.4 49.5
50.4 51.0 49.9 49.3
Example 10
ODHE Over NiTiSmX (X.dbd.Cs, Mg, Ca, Sb, Bi, V, Nb, Ta) and
NiTiNbTaSm Oxide Catalysts (#116297/16506/16650)
[0144] Catalyst compositions comprising various NiTiSniX oxides,
where X is Cs, Mg, Ca, Sb, Bi, T or Nlb were prepared in small
(.about.100 mg) quantities by precipitation substantially as
described in connection with Example 1. Table 10A summarizes the
composition and amounts of the various catalyst compositions.
[0145] In an initial screening (calcination at 300.degree. C., 8
hours, screening in fixed bed parallel reactor at 300.degree. C.
with flowrates of ethane:nitrogen:oxygen of 0.42:0.54:0.088 sccm,
as described), ethane conversion values for the NiTiSmCs oxide
compositions ranged from 13.8% (with ethylene selectivity of 76.5%)
to 18.2% (with ethylene selectivity of 83.7%), and ethylene
selectivity values ranged from 76.5% (with ethane conversion of
13.8%) to 84.7% (with ethane conversion of 18.0%). Ethane
conversion values for the NiTiSmMg oxide compositions ranged from
15.9% (with ethylene selectivity of 85.2%) to 19.1% (with ethylene
selectivity of 85.4%), and ethylene selectivity values ranged from
83.9% (with ethane conversion of 17.3%) to 85.7% (with ethane
conversion of 17.3%). Ethane conversion values for the NiTiSmCa
oxide compositions ranged from 14.5% (with ethylene selectivity of
78.7%) to 19.1% (with ethylene selectivity of 83.5%), and ethylene
selectivity values ranged from 78.7% (with ethane conversion of
14.5%) to 85.6% (with ethane conversion of 15.9%). Ethane
conversion values for the NiTiSmSb oxide compositions ranged from
15.6% (with ethylene selectivity of 83.2%) to 18.7% (with ethylene
selectivity of 83.1%), and ethylene selectivity values ranged from
81.5% (with ethane conversion of 16.3%) to 85.1% (with ethane
conversion of 17.9%). Ethane conversion values for the NiTiSmBi
oxide compositions ranged from 11.1% (with ethylene selectivity of
60.1%) to 17.9% (with ethylene selectivity of 86.1%), and ethylene
selectivity values ranged from 59.0% (with ethane conversion of
11.3%) to 86.1% (with ethane conversion of 17.9%). Ethane
conversion values for the NiTiSmV oxide compositions ranged from
12.1% (with ethylene selectivity of 76.5%) to 16.9% (with ethylene
selectivity of 83.5%), and ethylene selectivity values ranged from
74.8% (with ethane conversion of 13.3%) to 83.5% (with ethane
conversion of 16.9%). Ethane conversion (C) and ethylene
selectivity (S) values for the NiTiSmNb oxide compositions ranged
from 16.0% C, 80.4% S to 20.0% C, 85.5% S. Ethane conversion values
for the NiTiSmTa oxide compositions ranged from 6.1% (with ethylene
selectivity of 72.7%) to 20.0% (with ethylene selectivity of
85.5%), and ethylene selectivity values ranged from 72.7% with
ethane conversion of 6.1%) to 87.3% (with ethane conversion of
18.8%).
[0146] In a second screening in the fixed bed parallel reactor at
300.degree. C. with different flowrates (ethane:nitrogen:oxygen of
0.42:0.23:0.061sccm), ethane conversion values for the NiTiSmCs
oxide compositions ranged from 15.0% (with ethylene selectivity of
80.4%) to 19.3% (with ethylene selectivity of 88.4%), and ethylene
selectivity values ranged from 80.4% (with ethane conversion of
15.0%) to 90.2% (with ethane conversion of 18.3%). Ethane
conversion values for the NiTiSmMg oxide compositions ranged from
17.3% (with ethylene selectivity of 89.4%) to 20.0% (with ethylene
selectivity of 88.5%), and ethylene selectivity values ranged from
87.3% (with ethane conversion of 18.3%) to 90.2% (with ethane
conversion of 17.9%). Ethane conversion values for the NiTiSmCa
oxide compositions ranged from 15.2% (with ethylene selectivity of
83.9%) to 20.0% (with ethylene selectivity of 86.9%), and ethylene
selectivity values ranged from 83.9% (with ethane conversion of
15.2%) to 89.9% (with ethane conversion of 17.9%). Ethane
conversion values for the NiTiSmSb oxide compositions ranged from
15.9% (with ethylene selectivity of 86.9%) to 19.1% (with ethylene
selectivity of 88.1%), and ethylene selectivity values ranged from
85.2% (with ethane conversion of 17.3%) to 88.1% (with ethane
conversion of 19.1%). Ethane conversion values for the NiTiSmBi
oxide compositions ranged from 13.2% (with ethylene selectivity of
81.4%) to 19.9% (with ethylene selectivity of 85.8%), and ethylene
selectivity values ranged from 78.1% (with ethane conversion of
14.1%) to 85.9% (with ethane conversion of 16.7%). Ethane
conversion values for the NiTiSmV oxide compositions ranged from
14.5% (with ethylene selectivity of 81.8%) to 17.9% (with ethylene
selectivity of 84.3%), and ethylene selectivity values ranged from
78.7% (with ethane conversion of 15.1%) to 86.1% (with ethane
conversion of 17.1%). Ethane conversion (C) and ethylene
selectivity (S) values for the NiTiSmNb oxide compositions ranged
from l7.3% C, 84.7% S to 19.6% C, 89.1% S. Ethane conversion (C)
and ethylene selectivity (S) values for the NiTiSmNb oxide
compositions ranged-from 7.3% C, 72.8% S to 20.3% C, 89.5% S.
31TABLE 10A Catalyst composition (mole fraction) of NiTiSmX oxide
catalysts, where X is Cs, Mg, Ca, Sb, Bi, V or Nb, and sample mass,
"m" (mg) used in parallel fixed bed reactor screen. Col Row 1 2 3 4
5 6 1 Ni 0.6667 0.6593 0.6522 0.6452 0.6383 0.6316 Ti 0.3056 0.3022
0.2989 0.2957 0.2926 0.2895 Sm 0.0278 0.0275 0.0272 0.0269 0.0266
0.0263 Cs 0.0000 0.0110 0.0217 0.0323 0.0426 0.0526 m 48.8 49.5
50.3 50.2 50.2 50.5 2 Ni 0.6621 0.6557 0.6495 0.6434 0.6375 0.6316
Ti 0.3034 0.3005 0.2977 0.2949 0.2922 0.2895 Mg 0.0069 0.0164
0.0257 0.0349 0.0438 0.0526 Sm 0.0276 0.0273 0.0271 0.0268 0.0266
0.0263 m 49.4 50.2 50.6 49.5 49.3 50.3 3 Ni 0.6621 0.6557 0.6495
0.6434 0.6375 0.6316 Ti 0.3034 0.3005 0.2977 0.2949 0.2922 0.2895
Ca 0.0069 0.0164 0.0257 0.0349 0.0438 0.0526 Sm 0.0276 0.0273
0.0271 0.0268 0.0266 0.0263 m 49.7 49.2 50.8 50.5 50.2 50.6 4 Ni
0.6624 0.6560 0.6498 0.6437 0.6377 0.6318 Ti 0.3036 0.3007 0.2978
0.2950 0.2923 0.2896 Sm 0.0276 0.0273 0.0271 0.0268 0.0266 0.0263
Sb 0.0065 0.0160 0.0253 0.0345 0.0435 0.0524 m 50.7 49.6 49.6 49.8
50.6 49.7 5 Ni 0.6621 0.6557 0.6495 0.6434 0.6375 0.6316 Ti 0.3034
0.3005 0.2977 0.2949 0.2922 0.2895 Sm 0.0276 0.0273 0.0271 0.0268
0.0266 0.0263 Bi 0.0069 0.0164 0.0257 0.0349 0.0438 0.0526 m 49.5
50.5 49.8 49.5 51.3 49.5 6 Ni 0.6621 0.6557 0.6495 0.6434 0.6375
0.6316 Ti 0.3034 0.3005 0.2977 0.2949 0.2922 0.2895 Sm 0.0276
0.0273 0.0271 0.0268 0.0266 0.0263 V 0.0069 0.0164 0.0257 0.0349
0.0438 0.0526 m 50.3 45.0 49.5 49.7 50.6 50.0 7 Ni 0.6554 0.6360
0.6177 0.6005 0.5842 0.5687 Nb 0.0169 0.0460 0.0734 0.0993 0.1237
0.1469 Ti 0.3004 0.2915 0.2831 0.2752 0.2677 0.2607 Sm 0.0273
0.0265 0.0257 0.0250 0.0243 0.0237 m 49.5 50.3 49.5 49.4 50.5 49.6
8 Ni 0.6541 0.6350 0.6170 0.6000 0.5839 0.5686 Ti 0.2998 0.2911
0.2828 0.2750 0.2676 0.2606 Ta 0.0188 0.0475 0.0745 0.1000 0.1242
0.1471 Sm 0.0273 0.0265 0.0257 0.0250 0.0243 0.0237 m 49.2 50.2
49.9 51.1 50.1 50.0
[0147] In another independent experiment, a NiTiNbTaSm oxide
catalyst having the composition
Ni.sub.0.68Ti.sub.0.10Nb.sub.0.10Ta.sub.0.10Sm.sub- .0.02O.sub.x
was prepared and screened in the parallel fixed bed reactor.
Briefly, the following aqueous stock solutions were added to a
glass vial in the amounts indicated: nickel nitrate ([Ni]=1.0M, 2.0
ml), titanium oxalate ([Ti]=0.713M with oxalic acid 0.18M), niobium
oxalate ([Nb]=0.569M with oxalic acid 0.173M, 0.517 ml), tantalum
oxalate ([Ta]=0.650M with oxalic acid 0.14M, 0.452 ml) and samarium
nitrate ([Sm]=0.506M, 0.116 ml). Tetramethylammonium hydroxide
([NMe.sub.4OH]=1.44M, 3.06 ml) was injected into the catalyst
precursor composition, resulting in precipitation. To insure
adequate rnixing, distilled water (3.0 ml) was also injected into
the mixture. The resulting precipitate mixture was settled at
25.degree. C. for 2 hours, and then centrifuged at 3000 rpm. The
solution was decanted and the solids were dried under vacuum at
60.degree. C. in a vacuum oven. The dried materials were then
calcined by heating to 320.degree. C. at 5.degree. C./min and
maintaining at 320.degree. C. for 8 hours in air. After subsequent
cooling to 25.degree. C., solid NiTiNbTaSm oxide (0.296 g) was
obtained and 48.7 mg thereof was tested for ethane oxidative
dehydrogenation in the parallel fixed bed reactor at 300.degree. C.
with an ethane:oxygen flow of 0.42:0.083 sccm. Ethane conversion
(C) and ethylene selectivity (S) were determined to be 22.3% C and
85.2% S.
Example 11
ODHE Over NiTiSn/NiZrSn Oxide Catalysts (#16470/16505)
[0148] Catalyst compositions comprising various NiTiSn and NiZrSn
oxides were prepared and screened substantially as described in
connection with Example 1,%with tin acetate ([Sn=0.249 M]) aqueous
stock solution. The various catalyst compositions and amounts are
summarized in Table 11A (NiTiSn oxides) and Table 11B (NiZrSn
oxides).
[0149] For the NiTiSn oxide catalysts, in an initial screening
(calcination at 300.degree. C., 8 hours, screening in fixed bed
parallel reactor at 300.degree. C. with floarates of
ethane:nitrogen:oxygen of 0.42:0.54:0.088 sccm, as described),
ethane conversion values for the NiTiSn oxide compositions ranged
from 11.1% (with ethylene selectivity of 79.4%) to 19.2% (with
ethylene selectivity of 85.4%), and ethylene selectivity values
ranged from 79.2% (with ethane conversion of 14.8%) to 86.1% (with
ethane conversion of 18.2%).
[0150] In a second screening of these catalysts in the fixed bed
parallel reactor at 300.degree. C. with different flowrates
(ethane:nitrogen:oxygen of 1.04:0.21:0.055 sccm), ethane conversion
values for the NiTiSn oxide compositions ranged from 8.5% (with
ethylene selectivity of 90.8%) to 10.2% (with ethylene selectivity
of 94.0%), and ethylene selectivity values ranged from 90.8% (with
ethane conversion of 8.5%) to 94.3% (with ethane conversion of
9.9%).
[0151] In a third screening of these catalysts in the fixed bed
parallel reactor at a different temperature, 275.degree. C., and
with different flowrates (ethane:nitrogen:oxygen of
1.05:0.082:0.022), ethane conversion values for the NiTiSn oxide
compositions ranged from 3.5% (with ethylene selectivity of 86.0%)
to 8.5% (with ethylene selectivity of 92.8%), and ethylene
selectivity values ranged from 85.4% (with ethane conversion of
4.4%) to 93.4% (with ethane conversion of 7.9%).
[0152] For the NiZrSn oxide catalysts, in an initial screening
(calcination at 300.degree. C., 8 hours, screening in fixed bed
parallel reactor at 300.degree. C. with flowrates of
ethane:nitrogen:oxygen of 0.42:0.54:0.088 sccm, as described),
ethane conversion values for the NiZrSn oxide compositions ranged
from 15.0% (with ethylene selectivity of 77.3%) to 17.8% (with
ethylene selectivity of 80.9%), and ethylene selectivity values
ranged from 77.2% (with ethane conversion of 15.6%) to 81.9% (with
ethane conversion of 17.1%).
[0153] In a second screening of these catalysts in the fixed bed
parallel reactor at 300.degree. C. with different flonvrates
(ethane:nitrogen:oxygen of 1.04:1.34:0.22 sccm), ethane conversion
values for the NiZrSn oxide compositions ranged from 8.2% (with
ethylene selectivity of 87.8%) to 9.3% (with ethylene selectivity
of 90.9%), and ethylene selectivity values ranged from 87.8% (with
ethane conversion of 8.2%) to 91.8% (with ethane conversion of
9.1%).
[0154] In a third screening of these catalysts in the fixed bed
parallel reactor at a different temperature, 275.degree. C., and
with different flowrates (ethane:nitrogen:oxygen of
1.04:0.021:0.055), ethane conversion values for the NiZrSn oxide
compositions ranged from 5.8% (with ethylene selectivity of 83.3%)
to 7.8% (with ethylene selectivity of 88.3% and ethylene
selectivity values ranged from 82.2% (with ethane conversion of
6.3%) to 88.9% (with ethane conversion of 7.6%).
32TABLE 11A Catalyst composition (mole fraction) of NiTiSn oxide
catalysts and sample mass (mg) used in parallel fixed bed reactor
screen. Column Row 1 2 3 4 5 6 1 Ni 0.875 Ti 0.125 Sn 0.000 mass
51.7 (mg) 2 Ni 0.862 0.787 Ti 0.129 0.213 Sn 0.009 0.000 mass 54.2
48.2 (mg) 3 Ni 0.847 0.771 0.708 Ti 0.134 0.220 0.292 Sn 0.019
0.008 0.000 mass 53.9 46.1 46.6 (mg) 4 Ni 0.832 0.755 0.691 0.637
Ti 0.139 0.228 0.301 0.363 Sn 0.029 0.018 0.008 0.000 mass 53.0
50.0 51.0 48.0 (mg) 5 Ni 0.815 0.736 0.672 0.618 0.572 Ti 0.145
0.236 0.311 0.374 0.428 Sn 0.040 0.027 0.017 0.008 0.000 mass 45.0
52.3 50.0 52.8 46.1 (mg) 6 Ni 0.796 0.717 0.652 0.598 0.552 0.513
Ti 0.151 0.245 0.322 0.386 0.441 0.487 Sn 0.052 0.038 0.026 0.016
0.007 0.000 mass 49.5 46.4 52.0 44.9 50.6 49.1 (mg)
[0155]
33TABLE 11B Catalyst composition (mole fractions) of NiZrSn oxide
catalysts and sample mass (mg) used in parallel fixed bed reactor
screen. Column Row 1 2 3 4 5 6 1 Ni 0.914 Zr 0.086 Sn 0.000 mass
45.8 (mg) 2 Ni 0.901 0.849 Zr 0.089 0.151 Sn 0.009 0.000 mass 52.9
51.2 (mg) 3 Ni 0.888 0.834 0.786 Zr 0.093 0.157 0.214 Sn 0.020
0.009 0.000 mass 50.9 50.6 47.6 (mg) 4 Ni 0.873 0.818 0.770 0.727
Zr 0.097 0.163 0.221 0.273 Sn 0.031 0.019 0.009 0.000 mass 55.6
54.4 53.1 51.2 (mg) 5 Ni 0.857 0.801 0.752 0.708 0.670 Zr 0.101
0.169 0.230 0.283 0.330 Sn 0.043 0.030 0.019 0.009 0.000 mass 55.1
51.8 49.2 53.8 49.2 (mg) 6 Ni 0.839 0.782 0.732 0.688 0.649 0.615
Zr 0.105 0.176 0.239 0.293 0.342 0.385 Sn 0.056 0.042 0.029 0.018
0.009 0.000 mass 51.8 51.3 45.5 59.0 50.7 50.6 (mg)
Example 12
ODHE Over Bulk NiTa, NiNb, NiNbTa (Various Forms), NiNbTaCe,
NiTa(Ce, Dy), and NiNb(Ce, Sb, Dy, Sm) Oxide Catalysts
[0156] In a first group of experiments, various NiTa, NiTaNb,
NiNbCe and NiNbSb oxide catalysts were prepared in large, bulk
quantities (.about.20 g), and .about.50 mg thereof was screened in
the parallel fixed bed reactor at 300.degree. C. with
ethane:nitrogen:oxygen flow of 0.42:0.54:0.058 sccm, as follows.
Catalyst compositions, sample mass, and resulting ethane conversion
and ethylene selectivity are summarized in Table 12A.
[0157] (#120S7) Ni.sub.0.83Ta.sub.0.17: Aqueous solution of nickel
nitrate (1.0M, 167.0 ml) was mixed with tantalum oxalate (0.66M in
water with 0.26M oxalic acid, 53.0 ml). To the stirring mixture of
nickel nitrate and tantalum oxalate, tetramethylammonium hydroxide
aqueous solution (1.42M, 210.0 ml) was added to give precipitation.
The water in the mixture was removed by freeze-drying, and the
resulting solid was then calcined under an atmosphere of air at the
heating rate of 1.degree. C./min to the temperature of 120.degree.
C., dwelled at 120 C for 2 hrs, at the heating rate of 1.degree.
C./min to 180.degree. C., dwelled at 180.degree. C. for 2 hrs, the
heating rate of 2.degree. C./min to 400.degree. C. and dwelled at
400.degree. C. for 8 hrs, and then cooled to 25.degree. C. Gray
solid NiTa oxide (18.0 g) were obtained and 50.0 mg thereof was
tested in the fixed bed parallel reactor for ethane oxidative
dehydrogenation under the aforementioned conditions.
[0158] (#12277) Ni.sub.0.62Ta.sub.0.19Nb.sub.0.19: Aqueous solution
of nickel nitrate (1.0M, 153.0 ml), tantalum oxalate aqueous
solution (0.66M in water with 0.26M oxalic acid, 73.0 ml), and
niobium oxalate aqueous solution (0.62M in water wvith 0.35M oxalic
acid, 76.0 ml) were mixed in a 2 L beaker. While the solution was
vigorously stirred by a mechanical stir, ammonium carbonate aqueous
solution (1.62M, 285.0 ml) was added in a controlled manner so that
the foam was formed slowly to give precipitation. The mixture was
transferred to containers, which was centrifuged at 4000 rpm for 15
minutes. The solution was decanted and solid materials were further
dried at 60.degree. C. under reduced pressure for 5 hours. The
resulting solid materials were calcined under an atmosphere of air
at 3.degree. C./min to 350.degree. C. and dwelled at 350.degree. C.
for 8 hours, and then cooled to 25.degree. C. Dark gray solid
NiTailb oxide (19.0 g) was obtained, and 50.0 mg thereof was tested
in the parallel fixed bed reactor for ethane oxidative
dehydrogenation under the aforementioned conditions.
[0159] (#12442) Ni.sub.0.62Ta.sub.0.10Nb.sub.0.28: Aqueous solution
of nickel nitrate (1.0M, 80.0 ml), tantalum oxalate aqueous
solution (0.66M in water with 0.26M oxalic acid, 19.0 ml), and
niobium oxalate aqueous solution (0.62M in water with 0.35M oxalic
acid, 57.0 ml) were mixed in a 2 L beaker. While the solution was
vigorously stirred by a mechanical stir, ammonium carbonate aqueous
solution (1.62M, 143.0 ml) was added in a controlled manner so that
the foam was formed slowly to give precipitation. The mixture was
transferred to containers, which was centrifuged at 4000 rpm for 15
minutes. The solution was decanted and solid materials were further
dried at 60.degree. C. under reduced pressure for 5 hours. The
resulting solid materials were calcined under an atmosphere of air
at 2.degree. C./min to 300.degree. C. and dwelled at 300.degree. C.
for 8 hours, and then cooled to 25.degree. C. Dark gray solid
NiTaNb oxide (12.0 g) was obtained and about 50 mg thereof was
tested in the parallel fixed bed reactor for ethane oxidative
dehydrogenation under the aforementioned conditions.
[0160] (#14560) Ni.sub.0.65Nb.sub.0.33Ce.sub.0.02O.sub.x: Aqueous
solution of nickel nitrate (1.0M, 150.0 ml), niobium oxalate
aqueous solution (0.58M in water with 0.14M oxalic acid, 131.0 ml),
and cerium nitrate (1.0M, 4.6 ml) were mixed in a 2 L beaker. While
the solution was vigorously stirred by a mechanical stir, ammonium
carbonate aqueous solution (1.62M, 214.7 ml) was added in a
controlled manner so that the foam was formed slowly to give
precipitation. The mixture was transferred to containers, which was
centrifuged at 4000 rpm for 15 minutes. The solution was decanted
and solid materials were further dried at 60.degree. C. under
reduced pressure for 5 hours. The resulting solid materials were
calcined under an atmosphere of air at 2.degree. C./min to
300.degree. C. and dwelled at 300.degree. C. for 8 hours, and then
cooled to 25.degree. C. Dark gray solid NiNbCe oxide (20.94 g) was
obtained and 45.8 mg thereof was tested in the parallel fixed bed
reactor for ethane oxidative dehydrogenation under the
aforementioned conditions.
[0161] (#14620) Ni.sub.0.65Nb.sub.0.23Ce.sub.0.02O.sub.x: NiNbCe
oxide (10.41 g) prepared as described above in connection with
library #14560 was further calcined to 400.degree. C. at 2.degree.
C./min and dwelled at 400.degree. C. for 8 hrs under an atmosphere
of air. Solid NiNbCe oxide (10.19 g) was obtained, and 49.2 mg
thereof was tested in the parallel fixed bed reactor for ethane
oxidative dehydrogenation under the aforementioned conditions.
[0162] (#14587) Ni.sub.0.71Nb.sub.0.27Sb.sub.0.2O.sub.x: Aqueous
solution of nickel nitrate (1.0M, 150.0 ml), niobium oxalate
aqueous solution (0.58M in water with 0.14M oxalic acid, 98.3 ml),
and antimony acetate aqueous solution (0.234M with oxalic acid
1.27M, 18.1 ml) were mixed in a 2 L beaker. While the solution was
vigorously stirred by a mechanical stir, ammonium carbonate aqueous
solution (1.62M, 228.4 ml) was added in a controlled manner so that
the foam was formed slowly to give precipitation. The mixture was
transferred to containers, which was centrifuged at 4000 rpm for 15
minutes. The solution was decanted and solid materials were further
dried at 60.degree. C. under reduced pressure for 5 hours. The
resulting solid materials were calcined under an atmosphere of air
at 2.degree. C./min to 300.degree. C. and dwelled at 300.degree. C.
for 8 hours, and then cooled to 25.degree. C. Dark gray solid
NiNbSb oxide (18.75 g) was obtained and 54.8 mg thereof was tested
in the parallel fixed bed reactor for ethane oxidative
dehydrogenation under the aforementioned conditions.
[0163] (#14624) Ni.sub.0.71Nb.sub.0.27Sb.sub.0.02O.sub.x: NiNbSb
oxide (8.86 g) prepared as described above in connection with
library #14587 was further calcined to 400.degree. C. at 2.degree.
C./min and dwelled at 400.degree. C. for 8 hrs under an atmosphere
of air. Solid NiNbSb oxide (8.60 g) was obtained, and 54.1 mg
thereof was tested in the parallel fixed bed reactor for ethane
oxidative dehydrogenation under the aforementioned conditions.
34TABLE 12A Catalyst composition (mole fractions), sample mass (mg)
arid performance characteristics of various NiTa, NiTaNb, NiNbCe
and NiNbSb oxide catalysts. Test conditions: 300.degree. C. with
ethane:nitrogen:oxygen flow of 0.42:0.54:0.088 sccm. Library Mass #
Composition (mg) Conversion Selectivity 12087
Ni.sub.0.83Ta.sub.0.17O.sub.x 50.0 11.1% 85.0% 12277
Ni.sub.0.62Ta.sub.0.19Nb.sub.0.19O.sub.x 50.0 10.0% 85.4% 12442
Ni.sub.0.62Ta.sub.0.10Nb.sub.0.28O.sub.x 50.0 17.0% 83.7% 14560
Ni.sub.0.65Nb.sub.0.33Ce.sub.0.02O.sub.x 45.8 18.6% 83.0% 14620
Ni.sub.0.65Nb.sub.0.33Ce.sub.0.02O.sub.x 49.2 13.8% 82.0% 14587
Ni.sub.0.71Nb.sub.0.27Sb.sub.0.02O.sub.x 54.8 20.2% 81.6% 14624
Ni.sub.0.71Nb.sub.0.27Sb.sub.0.02O.sub.x 54.1 14.4% 82.5%
[0164] In another group of experiments, various NiTa, NiTaCe,
NiTaDy, NiNbTaCe, NiNbDy, NiNb and titania supported NiNbSm oxide
catalysts were prepared in large, bulk quantities (.about.20 g),
and various amounts thereof were screened in the parallel fixed bed
reactor at 300.degree. C. with ethane:nitrogen:oxygen flow of
0.42:0.08:0.022 sccm, as follows. Catalyst compositions, sample
mass, and resulting ethane conversion and ethylene selectivity are
summarized in Table 12B.
[0165] (#15891) Ni.sub.0.86Ta.sub.0.14O.sub.x: Aqueous solution of
nickel nitrate (1.0M, 150.0 ml), and tantalum oxalate aqueous
solution (0.69M in water with 0.9M oxalic acid, 35.0 ml) were mixed
in a 1 L beaker. While the solution was vigorously stirred by a
mechanical stir, ammonium carbonate aqueous solution (1.62M, 150.0
ml) was added in a controlled manner so that the foam was formed
slowly to give precipitation. The mixture was transferred to
containers, which was centrifuged at 3000 rpm for 15 minutes. The
solution was decanted and solid materials were further dried at
60.degree. C. under reduced pressure for 5 hours. The resulting
solid materials were calcined under an atmosphere of air at
2.degree. C./min to 320.degree. C. and dwelled at 320.degree. C.
for 8 hours, and then cooled to 25.degree. C. Dark gray solid NiTa
oxide (15.0 g) was obtained and 45.6 mg thereof was tested in the
parallel fixed bed reactor for ethane oxidative dehydrogenation
under the aforementioned reaction conditions.
[0166] (#15915) Ni.sub.0.65Ta.sub.0.31Ce.sub.0.04O.sub.x: Aqueous
solution of nickel nitrate (1.0M, 120.0 ml), tantalum oxalate
aqueous solution (0.69M in water with 0.19M oxalic acid, 83.0 ml),
and cerium nitrate aqueous solution (0.50M, 15.0 ml) were mixed in
a 1 L beaker. While the solution was vigorously stirred by a
mechanical stir, ammonium carbonate aqueous solution (1.62M, 174.0
ml) was added in a controlled manner so that the foam was formed
slowly to give precipitation. The mixture was transferred to
containers, which was centrifuged at 3000 rpm for 15 minutes. The
solution was decanted and solid materials were further dried at
60.degree. C. under reduced pressure for 5 hours. The resulting
solid materials were calcined under an atmosphere of air at
2.degree. C./min to 320.degree. C. and dwelled at 320.degree. C.
for 8 hours, and then cooled to 25.degree. C. Dark gray solid
NiTaCe oxide (21.9 g) was obtained and 51.3 mg thereof was tested
in the parallel fixed bed reactor for ethane oxidative
dehydrogenation under the aforementioned reaction conditions.
[0167] (#15916) Ni.sub.0.73Ta.sub.0.24Dy.sub.0.03O.sub.x: Aqueous
solution of nickel nitrate (1.0M, 150.0 ml), tantalum oxalate
aqueous solution (0.51M in water with 0.67M oxalic acid, 97.0 ml),
and dysprosium acetate aqueous solution (0.294M, 21.0 ml) were
mixed in a 1 L beaker. While the solution was vigorously stirred by
a mechanical stir, ammonium carbonate aqueous solution (1.62M,
269.0 ml) was added in a controlled manner so that the foam was
formed slowly to give precipitation. The mixture was transferred to
containers, which was centrifuged at 3000 rpm for 15 minutes. The
solution was decanted and solid materials were further dried at
60.degree. C. under reduced pressure for 5 hours. The resulting
solid materials were calcined under an atmosphere of air at
2.degree. C./min to 320.degree. C. and dwelled at 320.degree. C.
for 8 hours, and then cooled to 25.degree. C. Dark gray solid
NiTaDy oxide (21.9 g) was obtained and 50.0 mg thereof was tested
in the parallel fixed bed reactor for ethane oxidative
dehydrogenation under the aforementioned reaction conditions.
[0168] (#15922)
Ni.sub.0.74Nb.sub.0.08Ta.sub.0.17Cc.sub.0.01O.sub.x: Aqueous
solution of nickel nitrate (1.0M, 150.0 ml), tantalum oxalate
aqueous solution (0.51M in water with 0.67M oxalic acid, 68.0 ml),
niobium oxalate aqueous solution (0.62M in water with 0.21M oxalic
acid, 26.0 ml), and cerium nitrate aqueous solution (0.50M, 4.0 ml)
were mixed in a 1 L beaker. While the solution was vigorously
stirred by a mechanical stir, ammonium carbonate aqueous solution
(1.62M, 235.0 ml) was added in a controlled manner so that the foam
was formed slowly to give precipitation. The mixture was
transferred to containers, which was centrifuged at 3000 rpm for 15
minutes. The solution was decanted and solid materials were further
dried at 60.degree. C. under reduced pressure for 5 hours. The
resulting solid materials were calcined under an atmosphere of air
at 2.degree. C./min to 320.degree. C. and dwelled at 320.degree. C.
for 8 hours, and then cooled to 25.degree. C. Dark gray solid
NiNbTaCe oxide (20.7 g) was obtained and 68.5 mg thereof was tested
in the parallel fixed bed reactor for ethane oxidative
dehydrogenation under the aforementioned reaction conditions.
[0169] (#15927) Ni.sub.0.68Nb.sub.0.25Dy.sub.0.07O.sub.x: Aqueous
solution of nickel nitrate (1.0M, 150.0 ml), niobium oxalate
aqueous solution (0.62M in water with 0.21M oxalic acid, 89.0ml),
and dysprosium acetate aqueous solution (0.294M, 53.0 ml) were
mixed in a 1 L beaker. While the solution was vigorously stirred by
a mechanical stir, ammonium carbonate aqueous solution (1.62M,
206.0 ml) was added in a controlled manner so that the foam was
formed slowly to give precipitation. The mixture was transferred to
containers, which was centrifuged at 3000 rpm for 15 minutes. The
solution was decanted and solid materials were further dried at
60.degree. C. under reduced pressure for 5 hours. The resulting
solid materials were calcined under an atmosphere of air at
2.degree. C./min to 320.degree. C. and dwelled at 320.degree. C.
for 8 hours, and then cooled to 25.degree. C. Dark gray solid
NiNbDy oxide (19.4 g) was obtained and 47.0 mg thereof tested in
the parallel fixed bed reactor for ethane oxidative dehydrogenation
under the aforementioned reaction conditions.
[0170] (#15931) Ni.sub.0.82Nb.sub.0.18O.sub.x: Aqueous solution of
nickel nitrate (1.0M, 150.0 ml), and niobium oxalate aqueous
solution (0.62M in water with 0.21M oxalic acid, 53.0 ml) were
mixed in a 1 L beaker. While the solution was vigorously stirred by
a mechanical stir, ammonium carbonate aqueous solution (1.62M,
164.0 ml) was added in a controlled manner so that the foam was
formed slowly to give precipitation. The mixture was transferred to
containers, which was centrifuged at 3000 rpm for 15 minutes. The
solution was decanted and solid materials were further dried at
60.degree. C. under reduced pressure for 5 hours. The resulting
solid materials were calcined under an atmosphere of air at
2.degree. C./min to 320.degree. C. and dwelled at 320.degree. C.
for 8 hours, and then cooled to 25.degree. C. Dark gray solid NiNb
oxide (14.1 g) was obtained and 47.3 mg thereof was tested in the
parallel fixed bed reactor for ethane oxidative dehydrogenation
under the aforementioned reaction conditions.
[0171] (#15944) Ni.sub.0.63Nb.sub.0.34SM.sub.0.03O.sub.x/TiO2:
TiO.sub.2 support in pellet form was dried at 100.degree. C. for
over 8 hrs. After cooling to 25.degree. C., TiO.sub.2 support was
impregnated with the mixed metal nitrate or oxalate solution.
Catalyst loading was about 6% by weight, relative to total weight
of the catalyst. After centrifugation, the solid materials obtained
were dried at 60.degree. C. under vacuum, and then calcined to
300.degree. C. at 2.degree. C./min and dwelled at 300.degree. C.
for 8 hrs. The NiNbSm oxide was obtained and .about.143 mg thereof
was tested in the parallel fixed bed reactor for ethane oxidative
dehydrogenation under the aforementioned reaction conditions.
35TABLE 12B Catalyst composition (mole fractions), sample mass (mg)
and performance characteristics of various NiTa, NiTaCe, NiTaDy,
NiNbTaCe, NiNbDy, NiNb and titania supported NiNbSm oxide
catalysts. Test conditions: 300.degree. C. with
ethane:nitrogen:oxygen flow of 0.42:0.08:0.022 sccm. Library Mass
Conver- Selec- # Composition (mg) sion tivity 15891
Ni.sub.0.86Ta.sub.0.14O.sub.x 45.6 mg 10.3% 91.3% 15915
Ni.sub.0.65Ta.sub.0.31Ce.sub.0.04O.sub.x 51.3 mg 10.5% 93.2% 15916
Ni.sub.0.73Ta.sub.0.24Dy.sub.0.03O.sub.x 50.0 mg 10.2% 93.3% 15922
Ni.sub.0.74Nb.sub.0.08Ta.sub.0.17Ce.sub.0.01O.sub.x 68.5 mg 10.8%
94.3% 15927 Ni.sub.0.68Nb.sub.0.25Dy.sub.0.07O.sub.x 47.0 mg 10.5%
91.8% 15931 Ni.sub.0.82Nb.sub.0.18O.sub.x 47.3 mg 10.2% 93.1% 15944
Ni.sub.0.63Nb.sub.0.34Sm.sub.0.03O.sub.x/TiO2* 142.8 mg 8.6% 93.0%
*Catalyst loading on the support is about 6% by weight.
[0172] In a third group of experiments, NiNbTa oxide catalysts of a
single composition were prepared in large, bulk quantities
(.about.20 g) and in various physical forms, and various amounts
thereof were screened in the parallel fixed bed reactor at
300.degree. C. with ethane:nitrogen:oxygen flow of 0.42:0.54:0.088
sccm, as follows. The catalyst composition, physical form, sample
mass and resulting ethane conversion and ethylene selectivity are
summarized in Table 12C.
[0173] (#6b 16116) Ni.sub.0.63Nb.sub.0.19Ta.sub.0.18O.sub.x:
Aqueous solution of nickel nitrate (1.0M, 150.0 ml), niobium
oxalate aqueous solution (0.62M in water with 0.21M oxalic acid,
73.0 ml), and tantalum oxalate aqueous solution (0.51M in water
with 0.67M oxalic acid, 84.0 ml), were mixed in a 1 L beaker. While
the solution was vigorously stirred by a mechanical stir,
tetramethylammonium hydroxide aqueous solution (1.28M, 390.0 ml)
was added quickly to give precipitation. Additional water (100 ml)
was added and mixed with the resulting mixture. The mixture was
transferred to containers, which was centrifuged at 3000 rpm for 15
minutes. The solution was decanted and solid materials were further
dried at 60.degree. C. under reduced pressure for 5 hours. The
resulting solid materials were calcined under an atmosphere of air
at 2.degree. C./min to 320.degree. C. and dwelled at 320.degree. C.
for 8 hours, and then cooled to 25.degree. C. Dark gray solid
NiNbTa oxide (15.9 g) was obtained and 50.0 mg thereof was tested,
as formed in bulk, in the parallel fixed bed reactor for ethane
oxidative dehydrogenation under the aforementioned reaction
conditions.
[0174] For comparison of the effect of physical form of the
catalyst, a portion of the NiNbTa oxide bulk catalyst prepared as
above was pressed and broken into small pieces (but not ground) to
fit into the reaction vessels of the parallel fixed bed reactor,
and 73.9 mg thereof was tested, in pressed and broken form, in the
parallel fixed bed reactor for ethane oxidative dehydrogenation
under the aforementioned reaction conditions. Additionally, another
portion of the NiNbTa oxide bulk catalyst prepared as described
above was pressed and ground, and 68.0 mg thereof was tested, in
pressed and ground form, in the parallel fixed bed reactor for
ethane oxidative dehydrogenation under the aforementioned reaction
conditions.
36TABLE 12C Physical form, sample mass (mg) and performance
characteristics of Ni.sub.0.63Nb.sub.0.19Ta.sub.0.18O.- sub.x
catalysts (#16116). Test conditions: 300.degree. C. with
ethane:nitrogen:oxygen flow of 0.42:0.54:0.088 sccm. Mass
Composition Form (mg) Conversion Selectivity
Ni.sub.0.63Nb.sub.0.19Ta.sub.0.18O.sub.x bulk 50.0 18.4 84.1
Ni.sub.0.63Nb.sub.0.19Ta.sub.0.18O.sub.x P*, B* 73.9 20.1 85.0
Ni.sub.0.63Nb.sub.0.19Ta.sub.0.18O.sub.x P*, G* 68.0 19.1 84.6 P* =
pressed; B* = broken (not ground); G* = ground.
Example 13
ODHE Over NiNbSmX Oxide Catalyst, X.dbd.Cs, Mg, Ca, Sb, Bi, V, Ti,
Ta (#16298/16507)
[0175] Catalyst compositions comprising various NiNbSmX oxides,
where X is Cs, Mg, Ca, Sb, Bi, V, Ti or Ta were prepared in bulk
(.about.20 g) quantities by precipitation substantially as
described in connection with Example 1. Nickel nitrate ([Ni]=1.0
M), niobium oxalate ([Nb]=0.569 M), samarium nitrate ([Sm]=0.506
M), cesium nitrate ([Cs]=1.00 M), magnesium nitrate ([Mg]=1.00 M),
calcium nitrate ([Ca]=1.00 M), antimony acetate ([Sb]=0.234 M),
bismuth citrate ([Bi]=0.293 M), vanadium oxalate ([V]=1.00 M),
titanium oxalate ([Ti]=0.713 M), and tantalum oxalate ([Ta]=0.650
M) aqueous stock solutions were used. Table 13A summarizes the
composition and amounts of the various catalyst compositions.
[0176] In an initial screening (calcination at 300.degree. C., 8
hours, screening in fixed bed parallel reactor at 300.degree. C.
with flowrates of ethane:nitrogen:oxygen of 0.42:0.54:0.088 sccm,
as described), ethane conversion (C) and ethylene selectivity (S)
values for the NiNbSmCs oxide compositions ranged from 16.3% C,
78.5% S to 19.2% C, 84.9% S. Ethane conversion values for the
NiNbSmMg oxide conmpositions ranged from 17.5% (with ethylene
selectivity of 83.1%) to 19.4% (with ethylene selectivity of
84.8%), and ethylene selectivity values ranged from 83.1% (with
ethane conversion of 17.5%) to 84.9% (with ethane conversion of
18.7%). Ethane conversion (C) and ethylene selectivity (S) values
for the NiNbSmCa oxide compositions ranged from 18.2% C, 83.3% S to
20.0% C, 84.5% S. Ethane conversion (C) and ethylene selectivity
(S) values for the NiNbSmSb oxide compositions ranged from 16.3% C,
80.3% S to 19.0% C, 86.4% S. Ethane conversion (C) and ethylene
selectivity (S) values for the NiNbSmBi oxide compositions ranged
from 17.1% C, 79.4% S to 19.5% C, 84.6% S. Ethane conversion values
for the NiNbSmV oxide compositions ranged from 13.8% (with ethylene
selectivity of 80.3%) to 17.7% (with ethylene selectivity of
84.3%), and ethylene selectivity values ranged from 79.9% (with
ethane conversion of 14.0%) to 84.3% (with ethane conversion of
17.7%). Ethane conversion (C) and ethylene selectivity (S) values
for the NiNbSmTi oxide compositions ranged from 17.6% C, 82.8% S to
19.1% C, 84.9% S. Ethane conversion values for the NiNbSmTa oxide
compositions ranged from 17.3% (with ethylene selectivity of 83.6%)
to 20.2% (with ethylene selectivity of 84.3%), and ethylene
selectivity values ranged from 83.4% (with ethane conversion of
17.8%) to 84.9% (with ethane conversion of 18.2%).
[0177] In a second screening in the fixed bed parallel reactor at
300.degree. C. with different flowrates (ethane:nitrogen:oxygen of
0.42:0.23:0.061 sccm), ethane conversion (C) and ethylene
selectivity (S) values for the NiNbSmCs oxide compositions ranged
from 17.0% C, 83.0% S to 19.8% C, 88.7% S. Ethane conversion values
for the NiNbSmMg oxide compositions ranged from 16.0% (with
ethylene selectivity of 88.3%) to 18.9% (with ethylene selectivity
of 88.2%), and ethylene selectivity values ranged from 86.4% (with
ethane conversion of 18.1%) to 88.3% (with ethane conversion of
18.8%). Ethane conversion values for the NiNbSmCa oxide
compositions ranged from 18.2% (with ethylene selectivity of 86.3%)
to 19.8% (with ethylene selectivity of 87.6%), and ethylene
selectivity values ranged from 86.3% (with ethane conversion of
18.2%) to 87.8% (with ethane conversion of 18.7%). Ethane
conversion values for the NiNbSmSb oxide compositions ranged from
17.0% (with ethylene selectivity of 84.2%) to 19.5% (with ethylene
selectivity of 89.3%), and ethylene selectivity values ranged from
84.2% (with ethane conversion of 17.0%) to 89.5% (with ethane
conversion of 19.4%). Ethane conversion values for the NiNbSmBi
oxide compositions ranged from 17.1% (with ethylene selectivity of
82.4%) to 19.8% (with ethylene selectivity of 87.7%), and ethylene
selectivity values ranged from 82.4% (with ethane conversion of
17.1%) to 88.7% (with ethane conversion of 18.5%). Ethane
conversion values for the NiNbSmV oxide compositions ranged from
14.0% (with ethylene selectivity of 76.7%) to 18.7% (with ethylene
selectivity of 86.8%), and ethylene selectivity values ranged from
76.7% (with ethane conversion of 14.0%) to 88.2% (with ethane
conversion of 17.8%). Ethane conversion values for the NiNbSmTi
oxide compositions ranged from 17.7% (with ethylene selectivity of
87.3%) to 19.4% (with ethylene selectivity of 88.0%), and ethylene
selectivity values ranged from 86.3% (with ethane conversion of
18.6%) to 88.2% (with ethane conversion of 19.1%). Ethane
conversion values for the NiNbSmTa oxide compositions ranged from
18.1% (with ethylene selectivity of 86.8%) to 19.0% (with ethylene
selectivity of 87.7%), and ethylene selectivity values ranged from
86.1% (with ethane conversion of 18.5%) to 87.8% (with ethane
conversion of 18.1%).
37TABLE 13A Catalyst composition (mole fraction) of NiNbSmX Oxide
Catalysts, where X is Cs, Mg, Ca, Sb, Bi, V, Ti or Ta, and sample
mass, "m" (mg) used in parallel fixed bed reactor screen. Col Row 1
2 3 4 5 6 1 Ni 0.7528 0.7439 0.7352 0.7267 0.7184 0.7103 Nb 0.2164
0.2138 0.2113 0.2089 0.2065 0.2042 Sm 0.0308 0.0304 0.0301 0.0297
0.0294 0.0291 Cs 0.0000 0.0118 0.0234 0.0347 0.0457 0.0565 m 49.4
49.9 49.3 50.6 50.6 50.8 2 Ni 0.7464 0.7389 0.7315 0.7243 0.7172
0.7103 Nb 0.2146 0.2124 0.2103 0.2082 0.2062 0.2042 Mg 0.0085
0.0185 0.0283 0.0379 0.0473 0.0565 Sm 0.0305 0.0302 0.0299 0.0296
0.0293 0.0291 m 49.6 49.8 49.3 49.7 49.9 50.4 3 Ni 0.7464 0.7389
0.7315 0.7243 0.7172 0.7103 Nb 0.2146 0.2124 0.2103 0.2082 0.2062
0.2042 Ca 0.0085 0.0185 0.0283 0.0379 0.0473 0.0565 Sm 0.0305
0.0302 0.0299 0.0296 0.0293 0.0291 m 49.3 50.2 50.7 49.9 49.2 50.1
4 Ni 0.7468 0.7392 0.7317 0.7244 0.7172 0.7102 Nb 0.2147 0.2125
0.2103 0.2082 0.2062 0.2041 Sm 0.0306 0.0302 0.0299 0.0296 0.0293
0.0291 Sb 0.0079 0.0181 0.0280 0.0378 0.0473 0.0567 m 50.8 49.8
50.2 50.9 50.8 49.9 5 Ni 0.7464 0.7389 0.7315 0.7243 0.7172 0.7103
Nb 0.2146 0.2124 0.2103 0.2082 0.2062 0.2042 Sm 0.0305 0.0302
0.0299 0.0296 0.0293 0.0291 Bi 0.0085 0.0185 0.0283 0.0379 0.0473
0.0565 m 50.9 50.6 50.2 49.4 49.3 49.9 6 Ni 0.7464 0.7389 0.7315
0.7243 0.7172 0.7103 Nb 0.2146 0.2124 0.2103 0.2082 0.2062 0.2042
Sm 0.0305 0.0302 0.0299 0.0296 0.0293 0.0291 V 0.0085 0.0185 0.0283
0.0379 0.0473 0.0565 m 50.4 49.8 50.8 51.0 49.4 49.6 7 Ni 0.7401
0.7156 0.6926 0.6711 0.6508 0.6317 Nb 0.2128 0.2057 0.1991 0.1929
0.1871 0.1816 Ti 0.0168 0.0494 0.0800 0.1086 0.1355 0.1608 Sm
0.0303 0.0293 0.0283 0.0275 0.0266 0.0258 m 49.7 49.7 50.6 49.5
50.5 50.3 8 Ni 0.7389 0.7163 0.6950 0.6750 0.6561 0.6383 Nb 0.2124
0.2059 0.1998 0.1940 0.1886 0.1835 Ta 0.0185 0.0485 0.0767 0.1033
0.1284 0.1521 Sm 0.0302 0.0293 0.0284 0.0276 0.0268 0.0261 m 49.4
49.5 49.9 50.4 50.7 50.0
Example 14
ODHE Over NiNbCu Oxide Catalysts. (#16360/16511)
[0178] Catalyst compositions comprising various NiNbCu oxides were
prepared in small (.about.100 mg) quantities by precipitation
substantially as described in connection with Example 1, using
copper nitrate ([Cu]=1.00 M) aqueous stock solution. Table 14A
summarizes the composition and amounts of the various catalyst
compositions.
[0179] In an initial screening (calcination at 300.degree. C., 8
hours, screening in fixed bed parallel reactor at 300.degree. C.
with flonvrates of ethane:nitrogen:oxygen of 0.42:0.54:0.088 sccm,
as described), ethane conversion (C) and ethylene selectivity (S)
values for the NiNbCu oxide compositions ranged from 7.2% C, 47.9%
S to 16.9% C, 79.7% S.
[0180] In a second screening in the fixed bed parallel reactor at
300.degree. C. with different flowrates (ethane:nitrogen:oxygen of
0.42:0.23:0.061 sccm), ethane conversion values for the NiNbCu
oxide compositions ranged from 7.4% (with ethylene selectivity of
48.2%) to 16.9% (with ethylene selectivity of 83.2%), and ethylene
selectivity values ranged from 48.2% (with ethane conversion of
7.4%) to 83.6% (with ethane conversion of 16.2%).
[0181] In a third screening in the fixed bed parallel reactor at
300.degree. C. with different flowrates (ethane:nitrogen:oxygen of
0.42:0.082:0.022 sccm), ethane conversion (C) and ethylene
selectivity (S) values for the NiNbCu oxide compositions ranged
from 4.1% C, 54.6% S to 10.2% C, 91.4% S.
38TABLE 14A Catalyst compositions (mole fraction) of NiNbCu Oxide
Catalysts and sample mass, "m" (mg) used in parallel fixed bed
reactor screen. Col Row 1 2 3 4 5 6 1 Ni 0.8574 0.7923 0.7263
0.6594 0.5915 0.5226 Nb 0.1426 0.2077 0.2737 0.3406 0.4085 0.4774
Cu 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 m 49.8 50.7 50.7 49.3
50.2 49.7 2 Ni 0.8530 0.7882 0.7226 0.6559 0.5884 0.5198 Nb 0.1419
0.2066 0.2723 0.3388 0.4064 0.4749 Cu 0.0051 0.0052 0.0052 0.0052
0.0053 0.0053 m 50.9 49.5 50.5 50.8 50.7 49.4 3 Ni 0.8487 0.7842
0.7188 0.6525 0.5853 0.5171 Nb 0.1412 0.2056 0.2709 0.3371 0.4042
0.4724 Cu 0.0102 0.0103 0.0103 0.0104 0.0105 0.0105 m 49.2 50.0
50.3 49.6 49.8 50.7 4 Ni 0.8444 0.7802 0.7151 0.6492 0.5822 0.5144
Nb 0.1404 0.2045 0.2695 0.3353 0.4021 0.4699 Cu 0.0152 0.0153
0.0154 0.0155 0.0156 0.0157 m 50.6 49.4 50.0 50.9 50.0 50.7 5 Ni
0.8401 0.7762 0.7115 0.6458 0.5792 0.5117 Nb 0.1397 0.2035 0.2681
0.3336 0.4000 0.4674 Cu 0.0202 0.0203 0.0204 0.0206 0.0207 0.0209 m
50.8 50.4 50.3 50.0 49.9 50.4 6 Ni 0.8359 0.7723 0.7079 0.6425
0.5762 0.5090 Nb 0.1390 0.2024 0.2667 0.3319 0.3980 0.4650 Cu
0.0251 0.0252 0.0254 0.0256 0.0258 0.0260 m 50.0 50.4 50.6 49.8
49.9 50.4
Example 15
ODHE Over NiNbCo Oxide Catalysts (#16365/16512)
[0182] Catalyst compositions comprising various NiNbCo oxides were
prepared in small (.about.100 mg) quantities by precipitation
substantially as described in connection with Example 1, using
cobalt nitrate ([Co]=1.00 M) aqueous stock solution. Table 15A
summarizes the composition and amounts of the various catalyst
compositions.
[0183] In an initial screening (calcination at 300.degree. C., 8
hours, screening in fixed bed parallel reactor at 300.degree. C.
with flonvrates of ethane:nitrogen:oxygen of 0.42:0.54:0.088 sccm,
as described), ethane conversion values for the NiNbCo oxide
compositions ranged from 7.6% (with ethylene selectivity of 80.7%)
to 20.6% (with ethylene selectivity of 75% 85.9%), and ethylene
selectivity values ranged from 73.1% (with ethane conversion of
14.2%) to 85.9% (with ethane conversion of 20.6%).
[0184] In a second screening in the fixed bed parallel reactor at
300.degree. C. with different flowrates (ethane:nitrogen:oxygen of
0.42:0.23:0.061 sccm), ethane conversion values for the NiNbCo
oxide compositions ranged from 8.8% (with ethylene selectivity of
81.9%) to 19.9% (with ethylene selectivity of 88.0%), and ethylene
selectivity values ranged from 77.6% (with ethane conversion of
14.6%) to 88.0% (with ethane conversion of 19.9%).
[0185] In a third screening in the fixed bed parallel reactor at
300.degree. C. with different floodgates (ethane:nitrogen:oxygen of
0.42:0.082:0.022 sccm), ethane conversion values for the NiNbCo
oxide compositions ranged from 7.7% (with ethylene selectivity of
89.4%) to 11.8% (with ethylene selectivity of 93.2%), and ethylene
selectivity values ranged from 83.0% (with ethane conversion of
8.7%) to 92.9% (with ethane conversion of 11.7%).
39TABLE 15A Catalyst compositions (mole fraction) of NiNbCo oxide
catalysts and sample mass, "m" (mg) used in parallel fixed bed
reactor screen. Col Row 1 2 3 4 5 6 1 Ni 0.8552 0.7903 0.7245
0.6577 0.5900 0.5212 Nb 0.1422 0.2072 0.2730 0.3397 0.4075 0.4762
Co 0.0025 0.0025 0.0026 0.0026 0.0026 0.0026 m 50.5 49.9 50.9 49.6
50.4 49.4 2 Ni 0.8515 0.7868 0.7213 0.6547 0.5873 0.5189 Nb 0.1416
0.2062 0.2718 0.3382 0.4056 0.4740 Co 0.0069 0.0069 0.0070 0.0070
0.0071 0.0071 m 50.4 50.1 50.8 49.8 49.4 49.1 3 Ni 0.8478 0.7834
0.7181 0.6518 0.5847 0.5165 Nb 0.1410 0.2053 0.2706 0.3367 0.4038
0.4718 Co 0.0112 0.0113 0.0114 0.0115 0.0115 0.0116 m 50.9 50.0
50.0 50.5 49.3 49.6 4 Ni 0.8441 0.7799 0.7149 0.6489 0.5820 0.5142
Nb 0.1404 0.2044 0.2694 0.3352 0.4020 0.4697 Co 0.0155 0.0156
0.0157 0.0158 0.0160 0.0161 m 50.3 50.0 49.5 50.9 49.7 49.4 5 Ni
0.8404 0.7765 0.7118 0.6461 0.5795 0.5119 Nb 0.1398 0.2035 0.2682
0.3337 0.4002 0.4676 Co 0.0198 0.0199 0.0201 0.0202 0.0203 0.0205 m
49.3 50.8 49.9 50.7 50.4 50.3
Example 16
ODHE Over NiNbCr Oxide Catalysts. (#16373/16513)
[0186] Catalyst compositions comprising various NiNbCr oxides were
prepared in bulk (.about.20 g) quantities by precipitation
substantially as described in connection with Example 1, using
chromium nitrate ([Cr]=1.00 M) aqueous stock solution. Table 16A
summarizes the composition and amounts of the various catalyst
compositions.
[0187] In an initial screening (calcination at 300.degree. C., 8
hours, screening in fixed bed parallel reactor at 300.degree. C.
with flowrates of ethane:nitrogen:oxygen of 0.42:0.54:0.088 sccm,
as described), ethane conversion values for the NiNbCr oxide
compositions ranged from 11.7% (with ethylene selectivity of 71.9%)
to 18.1% (with ethylene selectivity of 82.7%, and ethylene
selectivity values ranged from 71.5% (with ethane conversion of
13.1%) to 83.8% (with ethane conversion of 17.7%).
[0188] In a second screening in the fixed bed parallel reactor at
300.degree. C. with different flowrates (ethane:nitrogen:oxygen of
0.42:0.23:0.061 sccm), ethane conversion values for the NiNbCr
oxide compositions ranged from 14.1% (with ethylene selectivity of
80.5%) to 18.6% (with ethylene selectivity of 86.7%), and ethylene
selectivity values ranged from 78.8% (with ethane conversion of
15.1%) to 87.0% (with ethane conversion of 18.3%).
[0189] In a third screening in the fixed bed parallel reactor at
300.degree. C. with different flowrates (ethane:nitrogen:oxygen of
0.42:0.082:0.022 sccm), ethane conversion values for the NiNbCr
oxide compositions ranged from 8.6% (with ethylene selectivity of
85.0%) to 11.2% (with ethylene selectivity of 90.0%), and ethylene
selectivity values ranged from 85.0% (with ethane conversion of
8.6%) to 91.5% (with ethane conversion of 10.9%).
40TABLE 16A Catalyst compositions (mole fraction) of NiNbCr Oxide
Catalysts and sample mass, "m" (mg) used in parallel fixed bed
reactor screen. Col Row 1 2 3 4 5 6 1 Ni 0.8552 0.7903 0.7245
0.6577 0.5900 0.5212 Nb 0.1422 0.2072 0.2730 0.3397 0.4075 0.4762
Cr 0.0025 0.0025 0.0026 0.0026 0.0026 0.0026 m 50.8 50.0 49.8 49.7
50.0 49.4 2 Ni 0.8504 0.7858 0.7203 0.6539 0.5865 0.5182 Nb 0.1414
0.2060 0.2714 0.3378 0.4051 0.4734 Cr 0.0081 0.0082 0.0082 0.0083
0.0084 0.0084 m 50.7 50.6 50.4 50.7 50.9 50.0 3 Ni 0.8457 0.7814
0.7162 0.6502 0.5832 0.5152 Nb 0.1407 0.2048 0.2699 0.3359 0.4028
0.4706 Cr 0.0137 0.0138 0.0139 0.0140 0.0141 0.0142 m 50.3 49.5
50.1 49.7 50.4 50.4 4 Ni 0.8410 0.7770 0.7122 0.6465 0.5798 0.5122
Nb 0.1399 0.2037 0.2684 0.3339 0.4005 0.4679 Cr 0.0192 0.0193
0.0194 0.0196 0.0197 0.0198 m 50.6 50.0 49.9 49.9 49.5 50.8 5 Ni
0.8363 0.7727 0.7082 0.6428 0.5765 0.5093 Nb 0.1391 0.2025 0.2669
0.3321 0.3982 0.4652 Cr 0.0246 0.0248 0.0249 0.0251 0.0253 0.0255 m
50.7 49.9 50.7 50.5 50.2 49.3
Example 17
ODHE Over NiNbGd/NiTaGd Oxide Catalysts (#13899)
[0190] Catalyst compositions comprising various NiNbGd and NiTaGd
oxides were prepared in small (.about.100 mg) quantities by
precipitation substantially as described in connection with Example
1, using gadolinium nitrate ([Gd]=1.00 M) aqueous stock solution,
and calcining to 320.degree. C. at 5.degree. C./min and maintaining
at 320.degree. C. for 8 hours in air. The compositions and amounts
of the various catalyst compositions are shown in Table 17A
(NiNbGd) and Table 17B (NiTaGd).
[0191] The NiNbGd oxide catalysts were screened in the fixed bed
parallel reactor for oxidative ethane dehydrogenation at
300.degree. C. with flowrates of ethane:nitrogen:oxygen of
0.42:0.54:0.088 sccm. Ethane conversion values for the NiNbGd oxide
compositions ranged from 4.9% (with ethylene selectivity of 48.2%)
to 20.3% (with ethylene selectivity of 83.2%), and ethylene
selectivity values ranged from 45.6% (with ethane conversion of
7.2%) to 83.9% (with ethane conversion of 17.6%).
[0192] The NiTaGd oxide catalysts were likewise screened in the
fixed bed parallel for oxidative ethane dehydrogenation reactor
(300%C; flonvrates of ethane:nitrogen:oxygen of 0.42:0.54:0.088
sccm). Ethane conversion values for the NiTaGd oxide compositions
ranged from 8.0% (with ethylene selectivity of 53.4%) to 19.0%
(with ethylene selectivity of 84.7%), and ethylene selectivity
values ranged from 51.7% (with ethane conversion of 8.3%) to 84.9%
(with ethane conversion of 16.2%).
[0193] Additional screens of the NiNbGd oxide catalysts were
effected at different temperatures (250.degree. C.;
ethane:nitrogen:oxygen flow of 0.42:0.54:0.088 sccm) and, in
separate experiments, at different flowrates (300.degree. C.;
ethane:nitrogen:oxygen flow of 1.05:1.35:0.22 sccm) (data not
shown).
41TABLE 17A Catalyst compositions (mole fractions) of NiNbGd oxide
catalysts and sample mass (mg) used in parallel fixed bed reactor
screen. Column Row 1 2 3 4 5 6 1 Ni 0.896 Nb 0.104 Gd 0.000 mass
47.3 (mg) 2 Ni 0.815 0.820 Nb 0.099 0.180 Gd 0.086 0.000 mass 50.8
54.7 (mg) 3 Ni 0.740 0.745 0.749 Nb 0.095 0.173 0.251 Gd 0.164
0.083 0.000 mass 52.2 49.8 46.9 (mg) 4 Ni 0.671 0.675 0.679 0.683
Nb 0.092 0.166 0.241 0.317 Gd 0.237 0.159 0.080 0.000 mass 49.6
54.9 49.7 52.8 (mg) 5 Ni 0.608 0.611 0.615 0.618 0.622 Nb 0.088
0.160 0.232 0.305 0.378 Gd 0.304 0.229 0.154 0.077 0.000 mass 55.2
54.0 50.5 49.7 47.0 (mg) 6 Ni 0.549 0.552 0.555 0.558 0.561 0.564
Nb 0.085 0.154 0.223 0.293 0.364 0.436 Gd 0.366 0.294 0.222 0.149
0.075 0.000 mass 50.7 50.5 50.7 51.4 52.9 45.0 (mg)
[0194]
42TABLE 17B Catalyst compositions (mole fractions) of NiTaGd oxide
catalysts and sample mass (mg) used in parallel fixed bed reactor
screen. Column Row 1 2 3 4 5 6 1 Ni 0.879 Ta 0.121 Gd 0.000 Mass
55.5 (mg) 2 Ni 0.800 0.793 Ta 0.116 0.207 Gd 0.084 0.000 Mass 50.9
51.4 (mg) 3 Ni 0.727 0.721 0.715 Ta 0.111 0.199 0.285 Gd 0.162
0.080 0.000 Mass 55.9 51.3 46.7 (mg) 4 Ni 0.660 0.655 0.649 0.644
Ta 0.107 0.191 0.274 0.356 Gd 0.233 0.154 0.076 0.000 Mass 52.7
53.0 53.6 51.7 (mg) 5 Ni 0.598 0.593 0.589 0.584 0.580 Ta 0.103
0.184 0.264 0.343 0.420 Gd 0.299 0.222 0.147 0.073 0.000 Mass 55.1
47.5 54.6 50.8 45.5 (mg) 6 Ni 0.540 0.536 0.532 0.528 0.525 0.521
Ta 0.099 0.178 0.255 0.331 0.405 0.479 Gd 0.360 0.286 0.213 0.141
0.070 0.000 Mass 49.6 51.8 51.8 52.8 55.6 48.6 (mg)
Example 18
ODHE Over NiNbBi and NiTaBi Oxide Catalysts
[0195] Catalyst compositions comprising various NiNbBi and NiTaBi
oxides were prepared in small (.about.100 mg) quantities by
precipitation substantially as described in connection with Example
1, using bismuth citrate ([Bi]=0.293 M) aqueous stock solution. The
compositions and amounts of the various catalyst compositions are
showvn in Table 18A (NiNbBi) and Table 18B (NiTaBi).
[0196] The NiNbBi oxide catalysts were initially screened in the
fixed bed parallel reactor for oxidative ethane dehydrogenation at
300.degree. C. with flowrates of ethane:nitrogen:oxygen of
0.42:0.54:0.088 sccm. Ethane conversion values for the NiNbBi oxide
compositions ranged from 13.1% (with ethylene selectivity of 72.9%)
to 19.8% (with ethylene selectivity of 84.2%), and ethylene
selectivity values ranged from 72.9% (with ethane conversion of
13.1%) to 84.9% (with ethane conversion of 17.5%)
[0197] The NiNbBi catalysts were subsequently recalcined to
400.degree. C. (5.degree. C./min to 400.degree. C.; dwell at
400.degree. C. for 8 hours), and then screened in the parallel
fixed bed reactor for ethane dehydrogenation under the same
reaction conditions as the initial screen (300.degree. C.;
ethane:nitrogen:oxygen flow of 0.42:0.54:0.088 sccm). Ethane
conversion values for the NiNbBi oxide compositions ranged from
9.9% (with ethylene selectivity of 85.6%) to 14.1% (with ethylene
selectivity of 85.2%), and ethylene selectivity values ranged from
74.6% (with ethane conversion of 12.7%) to 86.3% (with ethane
conversion of 13.3%)
[0198] The recalcined NiNbBi catalysts were screened again in the
parallel fixed bed reactor at different flowrates screen
(300.degree. C.; ethane:nitrogen:oxygen flow of 0.42:0.081:0.022
sccm). Ethane conversion values for the NiNbBi oxide compositions
ranged from 9.5% (with ethylene selectivity of 93.0%) to 10.9%
(with ethylene selectivity of 93.4%), and ethylene selectivity
values ranged from 89.8% (with ethane conversion of 10.2%) to 93.8%
(with ethane conversion of 10.6%).
[0199] The NiTaBi oxide catalysts were likewise initially screened
in the fixed bed parallel reactor for oxidative ethane
dehydrogenation reactor (300.degree. C.; flowrates of
ethane:nitrogen:oxygen of 0.42:0.54:0.088 sccm). Ethane conversion
values for the NiTaBi oxide compositions ranged from 13.6% (with
ethylene selectivity of 82.5%) to 19.1% (with ethylene selectivity
of 84.8%), and ethylene selectivity values ranged from 78.9% (with
ethane conversion of 13.7%) to 84.8% (with ethane conversion of
19.1%)
[0200] The NiTaBi catalysts were subsequently recalcined to
400.degree. C. (5.degree. C./min to 400.degree. C.; dwell at
400.degree. C. for 8 hours), and then screened in the parallel
fixed bed reactor for ethane dehydrogenation under the same
reaction conditions as the initial screen (300.degree. C.;
ethane:nitrogen:oxygen flow of 0.42:0.54:0.088 sccm). Ethane
conversion values for the NiTaBi oxide compositions ranged from
9.4% (with ethylene selectivity of 77.1%) to 13.5% (with ethylene
selectivity of 84.3%), and ethylene selectivity values ranged from
74.6% (with ethane conversion of 10.4%) to 86.9% (with ethane
conversion of 11.1%).
[0201] The recalcined NiTaBi catalysts were screened again in the
parallel fixed bed reactor at different flowrates screen
(300.degree. C.; ethane:nitrogen:oxygen flow of 0.42:0.081:0.022
sccm). Ethane conversion (C) and ethylene selectivity (S) values
for the NiTaBi oxide compositions ranged from 8.6% C, 87.8% S to
11.0% C, 93.6% S.
43TABLE 18A Catalyst compositions (mole fractions) of NiNbBi oxide
catalysts and sample mass (mg) used in parallel fixed bed reactor
screen. Column Row 1 2 3 4 5 6 1 Ni 0.890 Nb 0.110 Bi 0.000 Mass
53.9 (mg) 2 Ni 0.879 0.810 Nb 0.115 0.190 Bi 0.007 0.000 Mass 50.7
53.4 (mg) 3 Ni 0.867 0.796 0.736 Nb 0.119 0.197 0.264 Bi 0.014
0.006 0.000 mass 53.0 49.2 52.9 (mg) 4 Ni 0.853 0.781 0.721 0.668
Nb 0.125 0.205 0.273 0.332 Bi 0.022 0.013 0.006 0.000 mass 56.1
53.6 54.7 51.4 (mg) 5 Ni 0.839 0.765 0.704 0.651 0.606 Nb 0.130
0.214 0.284 0.343 0.394 Bi 0.031 0.021 0.013 0.006 0.000 mass 49.3
45.5 53.2 52.0 46.0 (mg) 6 Ni 0.824 0.748 0.685 0.632 0.587 0.547
Nb 0.136 0.223 0.295 0.355 0.407 0.453 Bi 0.040 0.029 0.020 0.012
0.006 0.000 mass 49.7 51.1 53.9 47.0 48.2 46.9 (mg)
[0202]
44TABLE 18B Catalyst compositions (mole fractions) of NiTaBi oxide
catalysts and sample mass (mg) used in parallel fixed bed reactor
screen. Column Row 1 2 3 4 5 6 1 Ni 0.906 Ta 0.094 Bi 0.000 mass
55.3 (mg) 2 Ni 0.891 0.835 Ta 0.098 0.165 Bi 0.011 0.000 mass 46.3
54.6 (mg) 3 Ni 0.876 0.819 0.769 Ta 0.101 0.170 0.231 Bi 0.023
0.011 0.000 mass 48.2 53.8 55.8 (mg) 4 Ni 0.859 0.801 0.751 0.706
Ta 0.105 0.176 0.239 0.294 Bi 0.036 0.022 0.010 0.000 mass 54.5
50.7 52.6 50.9 (mg) 5 Ni 0.841 0.783 0.731 0.687 0.647 Ta 0.109
0.183 0.247 0.303 0.353 Bi 0.049 0.034 0.021 0.010 0.000 mass 51.9
54.2 50.0 54.0 51.1 (mg) 6 Ni 0.822 0.762 0.711 0.665 0.626 0.591
Ta 0.114 0.190 0.256 0.314 0.364 0.409 Bi 0.064 0.048 0.033 0.021
0.010 0.000 mass 52.5 48.6 51.5 48.6 51.0 50.7 (mg)
Example 19
ODHE Over NiNbSb/NiTaSb Oxide Catalysts
[0203] Catalyst compositions comprising various NiNbSb and NiTaSb
oxides were prepared in small (.about.100 mg) quantities by
precipitation substantially as described in connection with Example
1, using antimony acetate ([Sb]=0.234 M) aqueous stock solution.
The compositions and amounts of the various catalyst compositions
are shown in Table 19A (NiNbSb) and Table 19B (NiTaSb).
[0204] The NiNbSb oxide catalysts were initially screened in the
fixed bed parallel reactor for oxidative ethane dehydrogenation at
300.degree. C. with flowrates of ethane:nitrogen:oxygen of
0.42:0.54:0.088 sccm. Ethane conversion (C) and ethylene
selectivity (S) values for the NiNbSb oxide compositions ranged
from 14.8% C, 67.6% S to 20.9% C, 84.4% S.
[0205] The NiNbSb catalysts were screened again in the parallel
fixed bed reactor at different flowrates screen (300.degree. C.,
ethane:nitrogen:oxygen flow of 1.04:1.34:0.22 sccm). Ethane
conversion values for the NiNbSb oxide compositions ranged from
11.8% (with ethylene selectivity of 81.1%) to 18.4% (with ethylene
selectivity of 84.0%), and ethylene selectivity values ranged from
77.0% (with ethane conversion of 12.6%) to 84.6% (with ethane
conversion of 12.7%).
[0206] The NiTaSb oxide catalysts were likewise initially screened
in the fixed bed parallel reactor for oxidative ethane
dehydrogenation reactor (300.degree. C.; flowrates of
ethane:nitrogen:oxygen of 0.42:0.54:0.088 sccm). Ethane conversion
values for the NiTaSb oxide compositions ranged from 14.5% (with
ethylene selectivity of 72.2%) to 18.7% (with ethylene selectivity
of 82.1%), and ethylene selectivity values ranged from 72.2% (with
ethane conversion of 14.5%) to 83.5% (with ethane conversion of
18.4%).
[0207] The NiTaSb catalysts were screened again in the parallel
fixed bed reactor at different flowrates screen (300.degree. C.;
ethane:nitrogen:oxygen flow of 1.04:1.34:0.22 sccm). Ethane
conversion values for the NiTaSb oxide compositions ranged from
10.0% (with ethylene selectivity of 69.5%) to 14.2% (with ethylene
selectivity of 80.2%), and ethylene selectivity values ranged from
69.5% (with ethane conversion of 10.0%) to 83.1% (wvitlh ethane
conversion of 13.4%).
45TABLE 19A Catalyst compositions (mole fractions) of NiNbSb oxide
catalysts and sample mass (mg) used in parallel fixed bed reactor
screen. Column Row 1 2 3 4 5 6 1 Ni 0.890 Nb 0.110 Sb 0.000 Mass
51.6 (mg) 2 Ni 0.879 0.814 Nb 0.115 0.186 Sb 0.006 0.000 Mass 45.0
49.8 (mg) 3 Ni 0.867 0.801 0.744 Nb 0.119 0.193 0.256 Sb 0.014
0.006 0.000 Mass 46.1 44.5 51.3 (mg) 4 Ni 0.854 0.786 0.728 0.678
Nb 0.125 0.201 0.266 0.322 Sb 0.021 0.013 0.006 0.000 Mass 51.0
53.3 46.1 48.3 (mg) 5 Ni 0.840 0.771 0.712 0.661 0.617 Nb 0.130
0.209 0.276 0.333 0.383 Sb 0.029 0.020 0.012 0.006 0.000 Mass 52.7
48.9 52.9 48.0 50.9 (mg) 6 Ni 0.825 0.754 0.694 0.643 0.599 0.560
Nb 0.136 0.218 0.287 0.345 0.396 0.440 Sb 0.039 0.028 0.019 0.012
0.006 0.000 Mass 49.7 45.9 46.6 47.3 51.4 54.8 (mg)
[0208]
46TABLE 19B Catalyst compositions (mole fractions) of NiTaSb oxide
catalysts and sample mass (mg) used in parallel fixed bed reactor
screen. Column Row 1 2 3 4 5 6 1 Ni 0.879 Ta 0.121 Sb 0.000 Mass
51.8 (mg) 2 Ni 0.868 0.788 Ta 0.126 0.212 Sb 0.006 0.000 Mass 50.3
52.2 (mg) 3 Ni 0.855 0.774 0.707 Ta 0.131 0.220 0.293 Sb 0.013
0.006 0.000 Mass 50.0 52.4 52.0 (mg) 4 Ni 0.842 0.759 0.691 0.634
Ta 0.137 0.228 0.303 0.366 Sb 0.021 0.013 0.006 0.000 Mass 51.4
51.1 50.2 50.4 (mg) 5 Ni 0.828 0.743 0.674 0.617 0.569 Ta 0.143
0.237 0.314 0.378 0.431 Sb 0.029 0.020 0.012 0.005 0.000 Mass 51.7
52.2 50.3 52.1 51.8 (mg) 6 Ni 0.812 0.726 0.656 0.598 0.550 0.509
Ta 0.149 0.247 0.326 0.391 0.445 0.491 Sb 0.038 0.027 0.018 0.011
0.005 0.000 Mass 50.0 50.3 50.5 51.6 51.5 50.3 (mg)
Example 20
ODHE Over NiNbSn/NiTaSn Oxide Catalysts. (#16467/#16469)
[0209] Catalyst compositions comprising various NiNbSn and NiTaSn
oxides were prepared in small (.about.100 mg) quantities by
precipitation substantially as described in connection wvith
Example 1, using tin acetate ([Sn]=0.249 M) aqueous stock solution.
The compositions and amounts of the various catalyst compositions
are shown in Table 20A (NiNbSn) and Table 20B (NiTaSn).
[0210] The NiNbSn oxide catalysts were initially screened in the
fixed bed parallel reactor for oxidative ethane dehydrogenation at
300.degree. C. with flowrates of ethane:nitrogen:oxygen of
0.42:0.54:0.088 sccm. Ethane conversion values for the NiNbSn oxide
compositions ranged from 15.1% (with ethylene selectivity of 82.0%)
to 19.4% (with ethylene selectivity of 84.8%), and ethylene
selectivity values ranged from 82.0% (with ethane conversion of
15.1%) to 85.8% (with ethane conversion of 19.2%).
[0211] The NiNbSn catalysts were screened again in the parallel
fixed bed reactor at different flownrates screen (300.degree. C.;
ethane:nitrogen:oxygen flow of 1.04:1.34:0.22 sccm). Ethane
conversion values for the NiNbSn oxide compositions ranged from
8.8% (with ethylene selectivity of 80.4%) to 13.3% (with ethylene
selectivity of 84.4%), and ethylene selectivity values ranged from
80.4% (with ethane conversion of 8.8%) to 85.9% (with ethane
conversion of 12.8%).
[0212] In a third screen, the NiN~bSn catalysts were screened in
the parallel fixed bed reactor at different flowrates screen
(300.degree. C.; ethane:nitrogen:oxygen flow of 1.04:0.21:0.055
sccm). Ethane conversion values for the NiNbSn oxide compositions
ranged from 8.4% (with ethylene selectivity of 91.8%) to 10.0%
(with ethylene selectivity of 93.5%), and ethylene selectivity
values ranged from 89.1% (with ethane conversion of 9.8%) to 93.5%
(with ethane conversion of 10.0%).
[0213] In a fourth screen, the NiNbSn catalysts were screened in
the parallel fixed bed reactor at different flowrates screen
(300.degree. C.; ethane:nitrogen:oxygen flow of 0.42:0.082:0.022
sccm). Ethane conversion (C) and ethylene selectivity (S) values
for the NiNbSn oxide compositions ranged from 8.7% C, 89.8% S to
11.5% C, 93.8% S.
[0214] The NiTaSn oxide catalysts were likewise initially screened
in the fixed bed parallel for oxidative ethane dehydrogenation
reactor (300.degree. C.; flowrates of ethane:nitrogen:oxygen of
0.42:0.54:0.088 sccm). Ethane conversion values for the NiTaSn
oxide compositions ranged from 16.6% (with ethylene selectivity of
84.6%) to 20.3% (with ethylene selectivity of 85.6%), and ethylene
selectivity values ranged from 84.1% (with ethane conversion of
18.3%) to 85.7% (with ethane conversion of 19.7%).
[0215] The NiTaSn catalysts were screened again in the parallel
fixed bed reactor at different floxvrates screen (300.degree. C.;
ethane:nitrogen:oxygen flow of 1.04:1.34:0.22 sccm). Ethane
conversion values for the NiTaSn oxide compositions ranged from
9.0% (with ethylene selectivity of 89.7%) to 11.0% (with ethylene
selectivity of 94.1%), and ethylene selectivity values ranged from
88.7% (with ethane conversion of 10.1%) to 94.2% (with ethane
conversion of 10.0%).
[0216] In a third screen, the NiTaSn catalysts were screened in the
parallel fixed bed reactor at a different temperature and at
different flowrates screen (275.degree. C.; ethane:nitrogen:oxygen
flow of 1.04:0.21:0.055 sccm). Ethane conversion values for the
NiTaSn oxide compositions ranged from 6.9% (with ethylene
selectivity of 91.8%) to 8.8% (with ethylene selectivity of 93.6%),
and ethylene selectivity values ranged from 91.3% (with ethane
conversion of 7.7%) to 94.1% (with ethane conversion of 7.7%).
47TABLE 20A Catalyst compositions (mole fractions) of NiNbSn oxide
catalysts and sample mass (mg) used in parallel fixed bed reactor
screen. Column Row 1 2 3 4 5 6 1 Ni 0.898 Nb 0.102 Sn 0.000 Mass
47.0 (mg) 2 Ni 0.885 0.823 Nb 0.106 0.177 Sn 0.009 0.000 Mass 53.6
50.4 (mg) 3 Ni 0.871 0.807 0.753 Nb 0.110 0.184 0.247 Sn 0.019
0.009 0.000 Mass 48.3 47.0 55.0 (mg) 4 Ni 0.856 0.791 0.735 0.687
Nb 0.115 0.191 0.256 0.313 Sn 0.030 0.018 0.009 0.000 Mass 52.0
54.1 52.7 51.5 (mg) 5 Ni 0.839 0.773 0.717 0.668 0.626 Nb 0.119
0.198 0.265 0.323 0.374 Sn 0.041 0.029 0.018 0.008 0.000 Mass 49.2
52.1 48.0 51.5 47.8 (mg) 6 Ni 0.821 0.754 0.697 0.648 0.606 0.569
Nb 0.125 0.206 0.275 0.335 0.386 0.431 Sn 0.054 0.040 0.028 0.017
0.008 0.000 Mass 54.5 50.2 46.4 51.9 53.2 47.8 (mg)
[0217]
48TABLE 20B Catalyst compositions (mole fractions) of NiTaSn oxide
catalysts and sample mass (mg) used in parallel fixed bed reactor
screen. Column Row 1 2 3 4 5 6 1 Ni 0.885 Ta 0.115 Sn 0.000 Mass
52.6 (mg) 2 Ni 0.872 0.802 Ta 0.119 0.198 Sn 0.009 0.000 mass 52.3
53.1 (mg) 3 Ni 0.857 0.787 0.727 Ta 0.124 0.205 0.273 Sn 0.019
0.009 0.000 mass 54.1 54.5 49.0 (mg) 4 Ni 0.842 0.770 0.710 0.658
Ta 0.129 0.212 0.282 0.342 Sn 0.029 0.018 0.008 0.000 mass 53.0
51.7 53.9 47.7 (mg) 5 Ni 0.825 0.752 0.691 0.639 0.594 Ta 0.134
0.220 0.292 0.353 0.406 Sn 0.041 0.028 0.017 0.008 0.000 mass 52.7
53.7 50.9 53.7 50.3 (mg) 6 Ni 0.807 0.733 0.671 0.619 0.574 0.536
Ta 0.140 0.229 0.302 0.365 0.418 0.464 Sn 0.053 0.039 0.027 0.016
0.008 0.000 mass 52.0 50.4 52.7 50.9 53.0 51.8 (mg)
Example 21
ODHE Over NiTaCe/NiNbCe/NiNbTaCe Oxide Catalysts.
(#12314/#12080/#12380/#1- 1285)
[0218] NiTaCe catalyst compositions were prepared in bulk by
precipitation substantially as described in connection with Example
1, using cerium nitrate ([Ce]=1.00 M) aqueous stock solution, and
calcining by heating to 350.degree. C. at 2.degree. C./min and
maintaining at 350.degree. C. for 8 hours in air. The compositions
and amounts of the various NiTaCe catalyst compositions are shonvn
in Table 21A.
[0219] The NiTaCe oxide catalysts wvere screened in the fixed bed
parallel reactor for oxidative ethane dehydrogenation at
300.degree. C. with flowrates of ethane:nitrogen:oxygen of
0.42:0.54:0.088 sccm. Ethane conversion values for the NiTaCe oxide
compositions ranged from 0.1% (with ethylene selectivity of 59.4%)
to 18.1% (with ethylene selectivtiy of 84.7%), and ethylene
selectivity values ranged from 31.9% (with ethane conversion of
2.8%) to 85.4% (with ethane conversion of 16.8%).
49TABLE 21A Catalysts compositions (mole fractions) of NiTaCe and
sample mass, "m" (mg) used in parallel fixed bed reactor screen.
Col Row 1 2 3 4 5 6 1 Ni 0.9681 0.8950 0.8178 0.7362 0.6498 0.5580
Ta 0.0319 0.1050 0.1822 0.2638 0.3502 0.4420 Ce 0.0000 0.0000
0.0000 0.0000 0.0000 0.0000 m 40.8 46.6 52.6 55.3 45.2 50.8 2 Ni
0.9569 0.8844 0.8079 0.7270 0.6414 0.5507 Ta 0.0316 0.1038 0.1800
0.2605 0.3457 0.4361 Ce 0.0115 0.0118 0.0121 0.0125 0.0128 0.0132 m
46.7 47.1 50.6 52.7 51.6 56.3 3 Ni 0.9461 0.8741 0.7982 0.7181
0.6333 0.5435 Ta 0.0312 0.1026 0.1778 0.2573 0.3414 0.4304 Ce
0.0227 0.0233 0.0239 0.0246 0.0253 0.0261 m 51.6 45.5 47.2 43.1
52.7 58.8 4 Ni 0.9355 0.8641 0.7888 0.7094 0.6254 0.5365 Ta 0.0309
0.1014 0.1757 0.2542 0.3371 0.4249 Ce 0.0337 0.0346 0.0355 0.0365
0.0375 0.0386 m 44.1 52.2 46.3 53.3 47.6 56.9 5 Ni 0.9251 0.8542
0.7796 0.7008 0.6177 0.5297 Ta 0.0305 0.1002 0.1737 0.2511 0.3329
0.4195 Ce 0.0444 0.0456 0.0468 0.0481 0.0494 0.0508 m 49.2 55.7
44.1 43.0 54.1 55.6 6 Ni 0.9149 0.8446 0.7706 0.6925 0.6101 0.5230
Ta 0.0302 0.0991 0.1716 0.2481 0.3289 0.4142 Ce 0.0549 0.0563
0.0578 0.0594 0.0610 0.0628 m 45.6 58.1 45.5 45 58.4 55.1
[0220] NiNbCe catalyst compositions were prepared by several
different methods, including freeze drying, precipitation with
tetraethylarunonium hydroxide, and precipitation with ammonium
carbonate, and then screened as discussed below. Briefly, in the
freeze drying method, NiNbCe catalyst compositions were prepared by
combining various amounts of the aqueous metal salt solutions to
form a catalyst precursor solution, and then freeze drying to
remove water. The NiNbCe catalyst compositions prepared by
precipitation with tetraethylammonium hydroxide were prepared
substantially as described in Example 1, using cerium nitrate
([Ce]=1.00 M), and using tetraethylammonium hydroxide as the
precipitating agent. In each of these two cases, the resulting
solid materials were calcined by heating to 120.degree. C. at
1.degree. C./min and dwelling at 120.degree. C. for 2 hours,
subsequently, heating to 180.degree. C. at 1.degree. C./min and
dwelling at 180.degree. C. for 2 hours, subsequently heating to
400.degree. C. at 2.degree. C./min and dwelling at 400.degree. C.
for 8 hours. The NiNbCe catalyst compositions prepared by
precipitation with ammonium carbonate were prepared substantially
as described in Example 1, using cerium nitrate ([Ce]=1.00 M), and
using ammonium carbonate as the precipitating agent. In this cases,
the resulting solid material was calcined by heating to 300.degree.
C. at 2.degree. C./min and dwelling at 300.degree. C. for 8 hours
in air. The compositions and amounts of the various NiNbCe catalyst
compositions are shown in Table 21B (prepared by freeze drying),
Table 21C (prepared by precipitation with tetraethylammonium
hydroxide) and Table 21D (prepared by precipitation with ammonium
carbonate).
[0221] The NiNbCe catalysts of Table 21B--prepared by freeze
drying--were screened in the fixed bed parallel reactor for
oxidative ethane dehydrogenation at 300.degree. C. with flowrates
of ethane:nitrogen:oxygen of 0.42:0.54:0.088 sccm. Ethane
conversion values for the NiNbCe oxide compositions ranged from
6.6% (with ethylene selectivity of 61.8%) to 11.7% (with ethylene
selectivity of 71.6%), and ethylene selectivity values ranged from
61.3% (with ethane conversion of 8.5%) to 74.3% (with ethane
conversion of 10.5%).
[0222] The NiNbCe catalysts of Table 21C--prepared by precipitation
with tetraethylamrnonium hydroxide--were likewise screened in the
fixed bed parallel reactor for oxidative ethane dehydrogenation at
300.degree. C. with flowrates of ethane:nitrogen:oxygen of
0.42:0.54:0.088 sccm. Ethane conversion values for the NiNbCe oxide
compositions ranged from 7.5% (with ethylene selectivity of 78.8%)
to 18.8% (with ethylene selectivity of 85.7%), and ethylene
selectivity values ranged from 58.9% (with ethane conversion of
10.1%) to 85.7% (with ethane conversion of 18.8%). These catalysts
were also screened in the parallel fixed bed reactor at different
flowrates (300.degree. C.; ethane:nitrogen:oxygen flow of
0.10:0.85:0.088 sccm) (data not shown).
[0223] The NiNbCe catalysts of Table 21D--prepared by precipitation
with ammonium carbonate--were likewise screened in the fixed bed
parallel reactor for oxidative ethane dehydrogenation at
300.degree. C. with flowrates of ethane:nitrogen:oxygen of
0.42:0.54:0.088 sccm. Ethane conversion values for the NiNbCe oxide
compositions ranged from 16.7% (with ethylene selectivity of 78.1%)
to 19.1% (with ethylene selectivity of 81.5%), and ethylene
selectivity values ranged from 78.1% (with ethane conversion of
16.7%) to 83.5% (with ethane conversion of 18.5%). These catalysts
were also screened in an ethylene co-feed (mixed feed) experiment
(data not shown). These catalysts were also screened again after
being recalcined by heating to 400.degree. C. at 2.degree. C./min
and dwelling at 400.degree. C. for 8 hours in air. (data not
shown).
50TABLE 21B Catalyst compositions (mole fractions) of NiNbCe oxide
catalysts prepared by freeze drying and sample mass (mg) used in
parallel fixed bed reactor screen. Column Row 1 2 3 4 5 6 7 1 Ni
0.907 Nb 0.068 Ce 0.024 Mass 41.5 (mg) 2 Ni 0.860 0.850 Nb 0.069
0.126 Ce 0.070 0.025 Mass 44.9 39.7 (mg) 3 Ni 0.812 0.802 0.792 Nb
0.071 0.128 0.183 Ce 0.118 0.071 0.025 Mass 43.1 40.4 37.4 (mg) 4
Ni 0.762 0.752 0.743 0.734 Nb 0.072 0.130 0.186 0.242 Ce 0.166
0.118 0.071 0.025 Mass 44.2 39.7 38.7 38.0 (mg) 5 Ni 0.710 0.701
0.692 0.684 0.675 Nb 0.073 0.132 0.189 0.246 0.300 Ce 0.217 0.167
0.118 0.071 0.025 Mass 39.3 43.1 37.8 43.6 39.7 (mg) 6 Ni 0.657
0.648 0.640 0.632 0.624 0.616 Nb 0.074 0.134 0.193 0.250 0.305
0.359 Ce 0.269 0.218 0.168 0.119 0.071 0.025 Mass 40.8 52.7 36.6
37.9 39.1 38.7 (mg) 7 Ni 0.601 0.593 0.586 0.578 0.571 0.563 0.556
Nb 0.075 0.137 0.196 0.254 0.310 0.365 0.419 Ce 0.323 0.270 0.219
0.168 0.119 0.072 0.025 Mass 42.3 38.7 44.9 35.1 35.8 37.4 36.1
(mg)
[0224]
51TABLE 21C Catalyst compositions (mole fractions) of NiNbCe oxide
catalysts prepared by precipitation with tetraethylammonium
hydroxide and sample mass (mg) used in parallel fixed bed reactor
screen. Column Row 1 2 3 4 5 6 1 Ni 0.942 Nb 0.058 Ce 0.000 Mass
52.7 (mg) 2 Ni 0.921 0.870 Nb 0.060 0.131 Ce 0.019 0.000 Mass 43.6
42.7 (mg) 3 Ni 0.898 0.847 0.801 Nb 0.062 0.134 0.199 Ce 0.040
0.019 0.000 Mass 46.4 53.1 51.3 (mg) 4 Ni 0.875 0.823 0.778 0.737
Nb 0.064 0.138 0.204 0.263 Ce 0.062 0.039 0.018 0.000 Mass 54.0
50.7 49.8 51.2 (mg) 5 Ni 0.849 0.798 0.752 0.712 0.675 Nb 0.066
0.142 0.210 0.270 0.325 Ce 0.085 0.060 0.038 0.018 0.000 Mass 48.0
52.9 52.1 49.2 52.9 (mg) 6 Ni 0.822 0.771 0.726 0.686 0.650 0.617
Nb 0.068 0.147 0.216 0.278 0.333 0.383 Ce 0.110 0.082 0.058 0.037
0.017 0.000 Mass 51.0 45.2 49.9 45.3 48.7 50.2 (mg)
[0225]
52TABLE 21D Catalyst compositions (mole fractions) of NiNbCe oxide
catalysts prepared by precipitation with ammonium-carbonate and
sample mass (mg) used in parallel fixed bed reactor screen. Column
Row 1 2 3 4 5 6 1 Ni 0.890 Nb 0.110 Ce 0.000 mass 48.5 (mg) 2 Ni
0.879 0.810 Nb 0.115 0.190 Ce 0.007 0.000 mass 48.1 49.0 (mg) 3 Ni
0.867 0.796 0.736 Nb 0.119 0.198 0.264 Ce 0.014 0.006 0.000 mass
55.2 46.2 51.6 (mg) 4 Ni 0.854 0.782 0.721 0.668 Nb 0.125 0.205
0.273 0.332 Ce 0.022 0.013 0.006 0.000 mass 51.0 51.5 54.7 47.9
(mg) 5 Ni 0.840 0.766 0.704 0.651 0.606 Nb 0.130 0.214 0.284 0.343
0.394 Ce 0.030 0.021 0.013 0.006 0.000 mass 51.9 54.4 51.4 54.4
53.4 (mg) 6 Ni 0.824 0.749 0.686 0.632 0.587 0.547 Nb 0.136 0.223
0.295 0.356 0.408 0.453 Ce 0.039 0.029 0.020 0.012 0.006 0.000 mass
45.4 52.7 49.1 49.0 47.8 52.8 (mg)
[0226] NiNbTaCe catalyst compositions were prepared in bulk by
precipitation substantially as described in connection with Example
1, using cerium nitrate ([Ce]=1.00 M) aqueous stock solution, and
calcining by heating to 350.degree. C. at 2.degree. C./min and
maintaining at 350.degree. C. for 8 hours in air. The compositions
and amounts of the various NiTaCe catalyst compositions are shown
in Table 21E.
[0227] The NiNbTaCe oxide catalysts were initially screened in the
fixed bed parallel reactor for oxidative ethane dehydrogenation at
300.degree. C. with flowrates of ethane:nitrogen:oxygen of
0.42:0.54:0.088 sccm. Ethane conversion values for the NiNbTaCe
oxide compositions ranged from 16.8% (with ethylene selectivity of
83.4%) to 20.8% (with ethylene selectivity of 84.0%), and ethylene
selectivity values ranged from 81.6% (with ethane conversion of
17.9%) to 84.0% (with ethane conversion of 20.8%).
[0228] The NiNbTaCe oxide catalysts were screened again in the
fixed bed parallel reactor for oxidative ethane dehydrogenation at
twvice the flonvrates as compared to the initial screen
(300.degree. C.; ethane:nitrogen:oxygen flow of 0.84:1.08:0.176
sccm). Ethane conversion values for the NiNbTaCe oxide compositions
ranged from 11.6% (with ethylene selectivity of 83.2%) to 16.6%
(with ethylene selectivity of 84.2%), and ethylene selectivity
values ranged from 80.0% (with ethane conversion of 12.7%) to 84.3%
(with ethane conversion of 15.5%).
53TABLE 21E Catalyst compositions (mole fractions) of NiNbTaCe
oxide catalysts and sample mass (mg) used in parallel fixed bed
reactor screen. Column Row 1 2 3 4 5 6 7 8 Table 21E, Part A 1 Ni
0.988 Nb 0.000 Ta 0.000 Ce 0.012 mass 49.2 (mg) 2 Ni 0.899 0.904 Nb
0.000 0.085 Ta 0.090 0.000 Ce 0.011 0.012 mass 45.3 47.5 (mg) 3 Ni
0.815 0.820 0.824 Nb 0.000 0.082 0.165 Ta 0.174 0.087 0.000 Ce
0.011 0.011 0.011 mass 52.8 53.5 47.4 (mg) Table 21E, Part B 4 Ni
0.738 0.741 0.745 0.749 Nb 0.000 0.079 0.159 0.240 Ta 0.252 0.169
0.085 0.000 Ce 0.011 0.011 0.011 0.011 mass 52.3 51.7 51.4 51.4
(mg) 5 Ni 0.665 0.668 0.671 0.675 0.678 Nb 0.000 0.077 0.154 0.232
0.311 Ta 0.325 0.245 0.164 0.083 0.000 Ce 0.010 0.010 0.010 0.011
0.011 mass 53.1 53.0 53.8 50.2 45.1 (mg) 6 Ni 0.596 0.599 0.602
0.605 0.608 0.611 Nb 0.000 0.074 0.149 0.225 0.302 0.379 Ta 0.394
0.316 0.238 0.160 0.080 0.000 Ce 0.010 0.010 0.010 0.010 0.010
0.010 mass 55.2 47.8 51.3 48.9 47.1 49.7 (mg) 7 Ni 0.532 0.535
0.537 0.540 0.542 0.545 0.547 Nb 0.000 0.072 0.145 0.218 0.292
0.367 0.443 Ta 0.458 0.384 0.308 0.232 0.156 0.078 0.000 Ce 0.010
0.010 0.010 0.010 0.010 0.010 0.010 mass 52.5 50.1 48.8 45.8 55.1
53.0 47.5 (mg) 8 Ni 0.472 0.474 0.476 0.478 0.480 0.483 0.485 0.487
Nb 0.000 0.070 0.141 0.212 0.284 0.356 0.429 0.503 Ta 0.519 0.447
0.374 0.301 0.226 0.152 0.076 0.000 Ce 0.009 0.010 0.010 0.010
0.010 0.010 0.010 0.010 mass 53.8 53.0 45.7 45.0 49.5 48.9 52.0
46.5 (mg)
Example 22
ODHE Over NiTaYb/NiNbYb Oxide Catalysts. (#13947/#13946)
[0229] Catalyst compositions comprising various NiTaY and NiNbYb
oxides were prepared in small (.about.100 mg) quantities by
precipitation substantially as described in connection with Example
1, using ytterbium nitrate pentahydrate ([Yb]=0.456M) aqueous stock
solution and calcining at 300.degree. C., as described. The
compositions and amounts of the various catalyst compositions are
shown in Table 22A (NiTaYb) and Table 22B (NiNbYb).
[0230] The NiTaYb oxide catalysts were screened in the fixed bed
parallel reactor for oxidative ethane dehydrogenation at
300.degree. C. with flowrates of ethane:nitrogen:oxygen of
0.42:0.54:0.088 sccm. Ethane conversion values for the NiTaYb oxide
compositions ranged from 13.5% (with ethylene selectivity of 75.1%)
to 20.0% (with ethylene selectivity of 83.9%), and ethylene
selectivity values ranged from 75.1% (with ethane conversion of
13.5%) to 84.7% (with ethane conversion of 19.1%).
[0231] The NiNbYb oxide catalysts were likewise screened in the
fixed bed parallel reactor for oxidative ethane dehydrogenation at
300.degree. C. with flowrates of ethane:nitrogen:oxygen of
0.42:0.54:0.088 sccm. Ethane conversion values for the NiNbYb oxide
compositions ranged from 10.5% (with ethylene selectivity of 68.8%)
to 19.4% (with ethylene selectivity of 83.0%), and ethylene
selectivity values ranged from 68.8% (with ethane conversion of
10.5%) to 84.0% (with ethane conversion of 18.3%).
54TABLE 22A Catalyst compositions (mole fractions) of NiTaYb oxide
catalysts and sample mass (mg) used in parallel fixed bed reactor
screen. Column Row 1 2 3 4 5 6 1 Ni 0.879 Ta 0.121 Yb 0.000 mass
51.2 (mg) 2 Ni 0.855 0.793 Ta 0.124 0.207 Yb 0.021 0.000 mass 53.9
51.0 (mg) 3 Ni 0.831 0.768 0.715 Ta 0.127 0.212 0.285 Yb 0.042
0.019 0.000 mass 51.0 54.0 54.6 (mg) 4 Ni 0.805 0.743 0.690 0.644
Ta 0.131 0.217 0.291 0.356 Yb 0.065 0.040 0.019 0.000 mass 49.5
52.6 53.2 50.5 (mg) 5 Ni 0.777 0.716 0.664 0.619 0.580 Ta 0.134
0.222 0.298 0.363 0.420 Yb 0.089 0.061 0.038 0.018 0.000 mass 49.4
47.9 50.8 52.7 47.8 (mg) 6 Ni 0.749 0.688 0.637 0.593 0.555 0.521
Ta 0.138 0.228 0.305 0.371 0.429 0.479 Yb 0.114 0.084 0.058 0.036
0.017 0.000 mass 51.6 54.0 53.4 53.3 52.5 53.1 (mg)
[0232]
55TABLE 22B Catalyst compositions (mole fractions) of NiNbYb oxide
catalysts and sample mass (mg) used in parallel fixed bed reactor
screen. Column Row 1 2 3 4 5 6 1 Ni 0.896 Nb 0.104 Yb 0.000 mass
51.8 (mg) 2 Ni 0.873 0.820 Nb 0.107 0.180 Yb 0.021 0.000 mass 49.0
54.5 (mg) 3 Ni 0.848 0.795 0.749 Nb 0.109 0.185 0.251 Yb 0.043
0.020 0.000 mass 53.7 48.8 45.9 (mg) 4 Ni 0.822 0.770 0.724 0.683
Nb 0.112 0.189 0.257 0.317 Yb 0.066 0.041 0.019 0.000 mass 52.5
52.2 46.2 52.4 (mg) 5 Ni 0.794 0.743 0.697 0.657 0.622 Nb 0.115
0.194 0.263 0.324 0.378 Yb 0.091 0.063 0.040 0.019 0.000 mass 52.0
49.1 48.3 52.2 53.4 (mg) 6 Ni 0.765 0.714 0.670 0.630 0.595 0.564
Nb 0.118 0.199 0.269 0.331 0.387 0.436 Yb 0.116 0.087 0.061 0.038
0.018 0.000 mass 49.9 51.8 48.9 46.8 54.8 47.6 (mg)
Example 23
ODHE Over NiTaEr/NiNbEr Oxide Catalysts. (#13950)
[0233] Catalyst compositions comprising various NiTaEr and NiNbEr
oxides were prepared in small (.about.100 mg) quantities by
precipitation substantially as described in connection with Example
1, using erbium acetate hydrate ([Er]=0.268 M) aqueous stock
solution and calcining at 300.degree. C., as described. The
compositions and amounts of the various NiTaEr and NiNbEr oxide
catalyst compositions are shown in Table 23A.
[0234] The NiTaEr and NiNbEr oxide catalysts (.about.50 mg) were
screened in the fixed bed parallel reactor for oxidative ethane
dehydrogenation at 300.degree. C. with flowrates of
ethane:nitrogen:oxygen of 0.42:0.54:0.088 sccm. Ethane conversion
values for the NiTaEr oxide compositions ranged from 12.9% (with
ethylene selectivity of 69.7%) to 19.4% (with ethylene selectivity
of 83.5%), and ethylene selectivity values ranged from 69.7% (with
ethane conversion of 12.9%) to 84.1% (with ethane conversion of
17.9%). Ethane conversion values for the NiNbEr oxide compositions
ranged from 12.5% (with ethylene selectivity of 65.0%) to 20.9%
(with ethylene selectivity of 83.9%), and ethylene selectivity
values ranged from 65.0% (with ethane conversion of 12.5%) to 85.0%
(with ethane conversion of 18.2%).
[0235] The NiTaEr and NiNbEr oxide catalysts (.about.50 mg) were
screened again in the fixed bed parallel reactor for oxidative
ethane dehydrogenation at a different temperature (250.degree. C.;
ethane:nitrogen:oxygen flow of 0.42:0.54:0.088 sccm). Ethane
conversion values for the NiTaEr oxide compositions ranged from
3.6% (with ethylene selectivity of 55.1%) to 7.8% (with ethylene
selectivity of 65.0%), and ethylene selectivity values ranged from
55.1% (with ethane conversion of 3.6%) to 76.6% (with ethane
conversion of 7.1%). Ethane conversion values for the NiNbEr oxide
compositions ranged from 3.5% (with ethylene selectivity of 44.3%)
to 7.4% (with ethylene selectivity of 74.4%), and ethylene
selectivity values ranged from 44.3% (with ethane conversion of
3.5%) to 83.6% (with ethane conversion of 6.6%).
56TABLE 23A Catalyst compositions (mole fractions) of NiTaEr/NiNbEr
oxide catalysts used in parallel fixed bed reactor screen. Col Row
1 2 3 4 5 6 1 Ni 1.000 0.919 0.842 0.768 0.696 0.628 Nb 0.000 0.000
0.000 0.000 0.000 0.000 Ta 0.000 0.081 0.158 0.232 0.304 0.372 Er
0.000 0.000 0.000 0.000 0.000 0.000 2 Ni 0.915 0.967 0.884 0.806
0.730 0.658 Nb 0.085 0.000 0.000 0.000 0.000 0.000 Ta 0.000 0.000
0.083 0.163 0.239 0.311 Er 0.000 0.033 0.032 0.032 0.031 0.030 3 Ni
0.835 0.881 0.932 0.848 0.768 0.691 Nb 0.165 0.087 0.000 0.000
0.000 0.000 Ta 0.000 0.000 0.000 0.086 0.167 0.245 Er 0.000 0.032
0.068 0.067 0.065 0.064 4 Ni 0.759 0.799 0.844 0.895 0.809 0.728 Nb
0.241 0.170 0.090 0.000 0.000 0.000 Ta 0.000 0.000 0.000 0.000
0.088 0.172 Er 0.000 0.031 0.066 0.105 0.103 0.100 5 Ni 0.686 0.722
0.761 0.806 0.855 0.768 Nb 0.314 0.248 0.174 0.092 0.000 0.000 Ta
0.000 0.000 0.000 0.000 0.000 0.091 Er 0.000 0.031 0.064 0.102
0.145 0.141 6 Ni 0.617 0.648 0.683 0.721 0.764 0.813 Nb 0.383 0.322
0.255 0.179 0.095 0.000 Ta 0.000 0.000 0.000 0.000 0.000 0.000 Er
0.000 0.030 0.063 0.099 0.140 0.187
Example 24
ODHE over NiTaDy/NiNbDy Oxide Catalysts. (#13949)
[0236] Catalyst compositions comprising various NiTaDy and NiNbDy
oxides were prepared in small (.about.100 mg) quantities by
precipitation substantially as described in connection with Example
1, using dysprosium acetate hydrate ([Dy]=0.294 M) aqueous stock
solution and calcining at 300.degree. C., as described. The
compositions and amounts of the various NiTaDy and NiNbDy oxide
catalyst compositions are shown in Table 24A.
[0237] The NiTaDy and NiNbDy oxide catalysts (.about.50 mg) were
screened in the fixed bed parllel reactor for oxidative ethane
dehydrogenation at 300.degree. C. with flowrates of
ethane:nitrogen:oxygen of 0.42:0.54:0.088 sccm. Ethane conversion
values for the NiTaDy oxide compositions ranged from 14.1% (with
ethylene selectivity of 71.2%) to 19.9% (with ethylene selectivity
of 84.4%), and ethylene selectivity values ranged from 71.2% (with
ethane conversion of 14.1%) to 84.7% (with ethane conversion of
17.3%). Ethane conversion values for the NiNbDy oxide compositions
ranged from 10.9% (with ethylene selectivity of 63.1%) to 18.9%
(with ethylene selectivity of 82.7%), and ethylene selectivity
values ranged from 63.1% (with ethane conversion of 10.9%) to 84.7%
(with ethane conversion of 18.4%).
[0238] The NiTaDy and NiNbDy oxide catalysts ( 50 mg) were screened
again in the fixed bed parallel reactor for oxidative ethane
dehydrogenation at a different temperature (250.degree. C.;
ethane:nitrogen:oxygen flow of 0.42:0.54:0.088 sccm). (data not
shown). These catalysts were also further calcined at 400.degree.,
and then screened again, in separate experiments, at 250.degree. C.
and at 300.degree. C., in each case with ethane:nitrogen:oxygen
flow of 0.42:0.54:0.088 sccm. (data not shown).
57TABLE 24A Catalyst compositions (mole fractions) of NiTaDy/NiNbDy
oxide catalysts used in parallel fixed bed reactor screen. Col Row
1 2 3 4 5 6 1 Ni 1.000 0.919 0.842 0.768 0.696 0.628 Nb 0.000 0.000
0.000 0.000 0.000 0.000 Ta 0.000 0.081 0.158 0.232 0.304 0.372 Dy
0.000 0.000 0.000 0.000 0.000 0.000 2 Ni 0.915 0.964 0.882 0.803
0.728 0.656 Nb 0.085 0.000 0.000 0.000 0.000 0.000 Ta 0.000 0.000
0.083 0.162 0.238 0.311 Dy 0.000 0.036 0.035 0.035 0.034 0.033 3 Ni
0.835 0.878 0.926 0.842 0.763 0.687 Nb 0.165 0.087 0.000 0.000
0.000 0.000 Ta 0.000 0.000 0.000 0.085 0.166 0.244 Dy 0.000 0.035
0.074 0.072 0.071 0.069 4 Ni 0.759 0.797 0.839 0.886 0.801 0.721 Nb
0.241 0.169 0.089 0.000 0.000 0.000 Ta 0.000 0.000 0.000 0.000
0.087 0.170 Dy 0.000 0.034 0.072 0.114 0.112 0.109 5 Ni 0.686 0.720
0.757 0.798 0.843 0.758 Nb 0.314 0.247 0.173 0.091 0.000 0.000 Ta
0.000 0.000 0.000 0.000 0.000 0.090 Dy 0.000 0.033 0.070 0.111
0.157 0.153 6 Ni 0.617 0.646 0.679 0.714 0.754 0.799 Nb 0.383 0.321
0.253 0.178 0.094 0.000 Ta 0.000 0.000 0.000 0.000 0.000 0.000 Dy
0.000 0.033 0.068 0.108 0.152 0.201
Example 25
ODHE Over NiNbSr/NitNbCs Oxide Catalysts. (#16892)
[0239] Catalyst compositions comprising various NiNbSr and NiNbCs
oxides were prepared in small (.about.100 mg) quantities dispensing
various amounts of aqueous metal solutions (nickel nitrate
([Ni]=1.0M), niobium oxalate ([Nb]=0.569M, excess oxalic acid
[H.sup.+]=0.346M), strontium nitrate ([Sr]=1.0M), and cesium
nitrate ([Cs]=1.00M) with an automated liquid handling robot into
an array of glass vials in an aluminum substrate. Magnetic stirbars
were added to each of the glass vials, and the precursor solutions
were heated at 120.degree. C. on a hot place with vigorous magnetic
stirring, such that the water in the solutions boiled off after
about 2 hours. The dried materials were then calcined by heating to
320.degree. C. at 5.degree. C./min and are dwelling at 320.degree.
C. for 8 hours in air, and subsequently cooled to 25.degree. C. The
compositions and amounts of the various NiNbSr and NiNbCs oxide
catalyst compositions are shown in Table 25A.
[0240] The NiNbSr and NiNbCs oxide catalysts (.about.50 mg) were
screened in the fixed bed parallel reactor for oxidative ethane
dehydrogenation at 300.degree. C. with flowrates of ethane:oxygen
of 0.42:0.058 sccm. Ethane conversion values for the NiNbSr oxide
compositions ranged from 17.4% (with ethylene selectivity of 84.4%)
to 22.0% (with ethylene selectivity of 87.5%), and ethylene
selectivity values ranged from 82.3% (with ethane conversion of
18.1%) to 89.6% (with ethane conversion of 21.2%). Ethane
conversion (C) and ethylene selectivity (S) values for the NiNbCs
oxide compositions ranged from 5.2% C, 15.2% S to 21.7% C, 87.5%
S.
[0241] The NiNbSr and NiNbCs oxide catalysts (.about.50 mg) were
screened again in the fixed bed parallel reactor for oxidative
ethane dehydrogenation at a different temperature and different
flowrates (275.degree. C.; ethane:oxygen flow of 0.42:0.033 sccm).
Ethane conversion values for the NiNTbSr oxide compositions ranged
from 10.6% (with ethylene selectivity of 84.5%) to 15.5% (with
ethylene selectivity of 91.4%), and ethylene selectivity values
ranged from 83.7% (with ethane conversion of 11.2%) to 91.4% (with
ethane conversion of 15.5%). Ethane conversion (C) and ethylene
selectivity (S) values for the NiNbCs oxide compositions ranged
from 3.3% C, 14.4% S to 14.4% C, 90.1% S.
58TABLE 25A Catalyst compositions (mole fractions) of NiNbSr/NiNbCs
oxide catalysts used in parallel fixed bed reactor screen. Column
Row 1 2 3 4 5 6 1 Ni 0.898 0.883 0.867 0.850 0.832 0.812 Nb 0.102
0.106 0.110 0.114 0.118 0.123 Sr 0.000 0.000 0.000 0.000 0.000
0.000 Cs 0.000 0.011 0.023 0.036 0.050 0.065 mass 51.2 51.5 51.4
50.0 48.3 54.2 (mg) 2 Ni 0.883 0.823 0.806 0.788 0.769 0.748 Nb
0.106 0.177 0.183 0.190 0.197 0.204 Sr 0.011 0.000 0.000 0.000
0.000 0.000 Cs 0.000 0.000 0.011 0.022 0.035 0.048 mass 53.2 50.1
50.9 51.8 51.3 47.5 (mg) 3 Ni 0.867 0.806 0.753 0.734 0.714 0.693
Nb 0.110 0.183 0.247 0.256 0.264 0.273 Sr 0.023 0.011 0.000 0.000
0.000 0.000 Cs 0.000 0.000 0.000 0.010 0.021 0.033 mass 52.4 52.1
51.6 49.500 48.300 51.100 (mg) 4 Ni 0.850 0.788 0.734 0.687 0.667
0.646 Nb 0.114 0.190 0.256 0.313 0.323 0.333 Sr 0.036 0.022 0.010
0.000 0.000 0.000 Cs 0.000 0.000 0.000 0.000 0.010 0.021 mass 52.2
50.6 53.8 51.5 52.300 54.400 (mg) 5 Ni 0.832 0.769 0.714 0.667
0.626 0.605 Nb 0.118 0.197 0.264 0.323 0.374 0.385 Sr 0.050 0.035
0.021 0.010 0.000 0.000 Cs 0.000 0.000 0.000 0.000 0.000 0.010 mass
46.4 51.1 49.2 51.5 49.9 54.200 (mg) 6 Ni 0.812 0.748 0.693 0.646
0.605 0.569 Nb 0.123 0.204 0.273 0.333 0.385 0.431 Sr 0.065 0.048
0.033 0.021 0.010 0.000 Cs 0.000 0.000 0.000 0.000 0.000 0.000 mass
52.3 53.6 50.0 48.8 50.5 54.4 (mg)
Example 26
Lifetime Tests for ODHE over Ni(Nb, Ta, Ti, Zr)-based Oxide
Catalysts
[0242] In a first set of experiments, long-term stability and
performance characteristics of various Ni(Nb, Ta, Ti, Zr)(Ce, Dy,
Er, Nd, Sm, Yb, Pr, Gd, Sb, Bi) oxide catalysts were evaluated in a
200 hour lifetime test. In a second set of experiments, long-term
stability and performance characteristics of various Ni(Nb, Ta,
Ti)(Sm, Sn, Co, Cs, Sb, Ag)(Mg, Ca, Li) oxide catalysts were
evaluated in a 400 hour lifetime test. As described below,
compositions and preparation methods were varied in the lifetime
tests. Test conditions were, in the 200 hour test, also varied
(data not shown).
[0243] 200 Hour Lifetime Test
[0244] In the 200 hour lifetime test, forty-two different Ni(Nb,
Ta, Ti, Zr)(Ce, Dy, Er, Nd, Sm, Yb, Pr, Gd, Sb, Bi) oxide catalysts
were prepared according to one of the following methods, designated
as Method A through Method F. The various catalyst compositions and
their method of preparation are shown in Table 26A.
[0245] Method A: Catalysts were prepared by precipitation with
tetramethylammonium hydroxide to the mixed metal nitrate or oxalate
solution. After centrifugation, the solid materials obtained were
dried at 60.degree. C. under vacuum, and then calcined to
300.degree. C. at 2.degree. C./min and dwelled at 300.degree. C.
for 8 hrs.
[0246] Method B: Catalysts were prepared by precipitation with
tetramethylammonium hydroxide to the mixed metal nitrate or oxalate
solution. After centrifugation, the solid materials obtained were
dried at 60.degree. C. under vacuum, and then calcined to
300.degree. C. at 2.degree. C./min and dwelled at 300.degree. C.
for 8 hrs. After cooling down to 25.degree. C., those catalysts
were calcined again to 400.degree. C. at 2.degree. C./min and dwell
at 400.degree. C. for 8 hrs.
[0247] Method C: Catalysts were prepared by precipitation with
ammonium carbonate to the mixed metal nitrate or oxalate solution.
After centrifugation, the solid materials obtained were dried at
60.degree. C. under vacuum, and then calcined to 300.degree. C. at
2.degree. C./min and dwelled at 300.degree. C. for 8 hrs.
[0248] Method D: Catalysts were prepared by precipitation with
ammonium carbonate to the mixed metal nitrate or oxalate solution.
After centrifugation, the solid-materials obtained were dried at
60.degree. C. under vacuum, and then calcined to 300.degree. C. at
2.degree. C./min and dwelled at 300.degree. C. for 8 hrs. After
cooling down to 25.degree. C., those catalysts were calcined again
to 400.degree. C. at 2.degree. C./min and dwell at 400.degree. C.
for 8 hrs.
[0249] Method E: TiO.sub.2 support in pellet form was dried at
100.degree. C. for over 8 hrs. After cooling to 25.degree. C.,
TiO.sub.2 support was impregnated with the mixed metal nitrate or
oxalate solution. After centrifugation, the solid materials
obtained were dried at 60.degree. C. under vacuum, and then
calcined to 300.degree. C. at 2.degree. C./min and dwelled at
300.degree. C. for 8 hrs.
[0250] Method F: Catalysts were prepared by precipitation with
tetramethylammonium hydroxide to the mixed metal nitrate or oxalate
solution. After centrifugation, the solid materials obtained are
dried at 60.degree. C. under vacuum, and then calcined to
400.degree. C. at 2.degree. C./min and dwelled at 400.degree. C.
for 8 hrs.
[0251] The forty-two catalysts of Table 26A (.about.50 mg),
together with six blanks, were screened simultaneously in the
48-channel parallel fixed bed reactor for oxidative ethane
dehydrogenation at 300.degree. C. with ethane:nitrogen:oxygen flow
of 0.42:0.54:0.088 sccm. Table 26B summarizes the amount of
catalyst screened, as well as the ethane conversion (C) and
ethylene selectivity (S) for each of the catalysts, measured after
various times during the test.
59TABLE 26A Catalyst composition and preparation methods for
catalysts screened in 200 hour lifetime test. Preparation Catalyst
Composition Method Table 26A, Part A Ni.sub.0.86Ta.sub.0.14O.sub.x
A Ni.sub.0.65Ta.sub.0.31Ce.sub.0.04O.sub.x A
Ni.sub.0.62Nb.sub.0.19Ta.sub.0.19Ce.sub.0.01O.sub.x A
Ni.sub.0.73Ta.sub.0.24Dy.sub.0.03O.sub.x A
Ni.sub.0.68Nb.sub.0.25Dy.sub.0.07O.sub.x A
Ni.sub.0.68Nb.sub.0.26Er.sub.0.06O.sub.x A blank n/a
Ni.sub.0.62Nb.sub.0.38O.sub.x A Ni.sub.0.71Ta.sub.0.23Nd.sub.0.06-
O.sub.x A Ni.sub.0.63Nb.sub.0.34Sm.sub.0.03O.sub.x A
Ni.sub.0.54Ta.sub.0.45Sm.sub.0.01O.sub.x A
Ni.sub.0.72Ti.sub.0.28O.sub.x A Ni.sub.0.66Ti.sub.0.29Yb.sub.0.05-
O.sub.x A blank n/a Table 26A, Part B
Ni.sub.0.62Nb.sub.0.34Ce.sub.0.04O.sub.x B
Ni.sub.0.62Ta.sub.0.34Ce.sub.0.04O.sub.x B
Ni.sub.0.76Nb.sub.0.17Er.sub.0.06O.sub.x B
Ni.sub.0.68Ta.sub.0.25Dy.sub.0.07O.sub.x B
Ni.sub.0.60Nb.sub.0.19Ta.sub.0.18Sm.sub.0.03O.sub.x B
Ni.sub.0.64Nb.sub.0.34Pr.sub.0.02O.sub.x B blank n/a
Ni.sub.0.63Nb.sub.0.37O.sub.x B Ni.sub.0.51Ta.sub.0.42Zr.sub.0.07-
O.sub.x B Ni.sub.0.73Ti.sub.0.27O.sub.x B
Ni.sub.0.58Ta.sub.0.34Gd.sub.0.07O.sub.x B
Ni.sub.0.68Nb.sub.0.24Gd.sub.0.08O.sub.x B
Ni.sub.0.80Nb.sub.0.19Sb.sub.0.01O.sub.x B blank n/a
Ni.sub.0.82Nb.sub.0.14Sb.sub.0.04O.sub.x B
Ni.sub.0.60Nb.sub.0.39Sb.sub.0.01O.sub.x A
Ni.sub.0.72Nb.sub.0.27Bi.sub.0.01O.sub.x B
Ni.sub.0.73Ta.sub.0.25Bi.sub.0.02O.sub.x B
Ni.sub.0.63Nb.sub.0.33Yb.sub.0.04O.sub.x B
Ni.sub.0.59Ta.sub.0.37Yb.sub.0.04O.sub.x B blank n/a
Ni.sub.0.65Nb.sub.0.33Ce.sub.0.02O.sub.x C
Ni.sub.0.71Nb.sub.0.27Sb.sub.0.02O.sub.x C
Ni.sub.0.65Nb.sub.0.33Ce.sub.0.02O.sub.x D
Ni.sub.0.63Nb.sub.0.19Ta.sub.0.18O.sub.x/TiO.sub.2 E
Ni.sub.0.71Nb.sub.0.27Sb.sub.0.02O.sub.x D
Ni.sub.0.65Nb.sub.0.33Ce.sub.0.02O.sub.x F blank n/a
Ni.sub.0.74Nb.sub.0.08Ta.sub.0.17Ce.sub.0.01O.sub.x F
Ni.sub.0.75Nb.sub.0.24Ce.sub.0.01O.sub.x F
Ni.sub.0.53Ta.sub.0.40Gd.sub.0.07O.sub.x A
Ni.sub.0.74Nb.sub.0.08Ta.sub.0.17Ce.sub.0.01O.sub.x A
Ni.sub.0.74Ta.sub.0.22Yb.sub.0.04O.sub.x A
Ni.sub.0.65Ta.sub.0.36Bi.sub.0.01O.sub.x A
[0252]
60TABLE 26B Catalyst composition, sample mass (mg) and ethane
conversion (C) and ethylene selectivity (S) measured at various
times on stream during screening in 200 hour lifetime test. Time on
stream (hour) 5.34 62.37 Mass C S C S Library # (mg) (%) (%) (%)
(%) Table 26B, Part A1 Ni.sub.0.86Ta.sub.0.14O.sub.x 49.4 18.1 83.5
18.2 83.3 Ni.sub.0.65Ta.sub.0.31Ce.sub.0.04O.sub.x 50 17.8 82.4
18.5 82.8 Ni.sub.0.62Nb.sub.0.19Ta.sub.0.19Ce.sub.0.01O.sub.x 50.4
16.4 84.3 14.3 84.6 Ni.sub.0.73Ta.sub.0.24Dy.sub.0.03O.sub.x 50.5
19.1 83.8 18.9 84.2 Ni.sub.0.68Nb.sub.0.25Dy.sub.0.07O.sub.x 49.8
18.6 83.6 18.9 83.6 Ni.sub.0.68Nb.sub.0.26Er.sub.0.06O.sub.x 49.8
19.0 83.0 18.1 83.1 Blank n/a 0.1 46.0 0.1 46.7
Ni.sub.0.62Nb.sub.0.38O.sub.x 49.2 19.6 85.2 18.2 85.5
Ni.sub.0.71Ta.sub.0.23Nd.sub.0.06O.sub.x 49.6 17.3 81.5 17.0 81.8
Ni.sub.0.63Nb.sub.0.34Sm.sub.0.03O.sub.x 50.4 21.1 85.0 20.3 85.2
Ni.sub.0.54Ta.sub.0.45Sm.sub.0.01O.sub.x 49.5 17.4 84.5 16.2 84.2
Ni.sub.0.72Ti.sub.0.28O.sub.x 50 18.7 85.0 18.3 85.5
Ni.sub.0.66Ti.sub.0.29Yb.sub.0.05O.sub.x 49.5 17.5 82.6 17.5 81.4
blank n/a 0.1 45.6 0.1 45.2 Ni.sub.0.62Nb.sub.0.34Ce.sub.0.04O.sub-
.x 42.6 15.7 81.0 14.9 81.8
Ni.sub.0.62Ta.sub.0.34Ce.sub.0.04O.sub.- x 47.6 14.7 81.7 14.9 82.3
Ni.sub.0.76Nb.sub.0.17Er.sub.0.06O.sub.x 45 13.4 84.8 12.6 84.7
Ni.sub.0.68Ta.sub.0.25Dy.sub.0.07O.sub.x 44.2 13.2 83.3 11.9 83.2
Ni.sub.0.60Nb.sub.0.19Ta.sub.0.18Sm.sub.0- .03O.sub.x 45.6 15.3
84.2 14.8 83.4 Ni.sub.0.64Nb.sub.0.34Pr.sub.0.- 02O.sub.x 48.1 15.5
84.6 14.6 83.9 blank n/a 0.1 44.3 0.1 42.6
Ni.sub.0.63Nb.sub.0.37O.sub.x 45.9 12.8 86.4 11.5 86.3
Ni.sub.0.51Ta.sub.0.42Zr.sub.0.07O.sub.x 44.5 15.0 83.3 13.9 82.6
Ni.sub.0.73Ti.sub.0.27O.sub.x 45.8 12.6 83.7 11.2 83.5
Ni.sub.0.58Ta.sub.0.34Gd.sub.0.07O.sub.x 45.6 10.4 83.5 9.4 83.2
Ni.sub.0.68Nb.sub.0.24Gd.sub.0.08O.sub.x 55.2 14.0 79.5 13.2 78.0
Ni.sub.0.80Nb.sub.0.19Sb.sub.0.01O.sub.x 48.6 14.0 85.6 12.4 85.5
blank n/a 0.1 38.5 0.1 37.9 Ni.sub.0.82Nb.sub.0.14Sb.sub.0.04O.sub-
.x 49.6 12.0 83.7 10.2 82.7
Ni.sub.0.60Nb.sub.0.39Sb.sub.0.01O.sub.- x 51.8 17.9 83.9 16.5 83.7
Ni.sub.0.72Nb.sub.0.27Bi.sub.0.01O.sub.x 54.7 15.4 85.9 15.1 85.8
Ni.sub.0.73Ta.sub.0.25Bi.sub.0.02O.sub.x 50 10.9 86.0 10.2 85.9
Ni.sub.0.63Nb.sub.0.33Yb.sub.0.04O.sub.x 41.1 13.9 83.3 12.7 82.7
Ni.sub.0.59Ta.sub.0.37Yb.sub.0.04O.sub.x 47.1 10.8 84.9 7.2 85.1
blank n/a 0.1 40.0 0.1 48.2
Ni.sub.0.65Nb.sub.0.33Ce.sub.0.02O.sub.x 48.3 16.5 82.6 15.4 79.8
Ni.sub.0.71Nb.sub.0.27Sb.sub.0.02O.sub.x 49.1 16.5 82.6 14.9 77.8
Table 26B, Part A2 Ni.sub.0.65Nb.sub.0.33Ce.sub.0.02O.sub.x 49.3
13.0 82.5 12.5 80.4 Ni.sub.0.63Nb.sub.0.19Ta.sub.0.18O.sub.x/TiO.s-
ub.2 145.9 7.9 89.1 5.9 89.8
Ni.sub.0.71Nb.sub.0.27Sb.sub.0.02O.sub- .x 51.5 11.2 81.5 8.8 77.6
Ni.sub.0.65Nb.sub.0.33Ce.sub.0.02O.sub.x 49.7 16.7 85.2 16.2 85.1
blank n/a 0.1 37.4 0.1 43.1
Ni.sub.0.74Nb.sub.0.08Ta.sub.0.17Ce.sub.0.01O.sub.x 50 16.1 84.3
16.8 84.9 Ni.sub.0.75Nb.sub.0.24Ce.sub.0.01O.sub.x 50.2 19.4 85.8
19.1 86.4 Ni.sub.0.53Ta.sub.0.40Gd.sub.0.07O.sub.x 48.9 16.8 78.8
16.2 77.4 Ni.sub.0.74Nb.sub.0.08Ta.sub.0.17Ce.sub.0.01O.sub.x 50.9
17.3 84.3 15.6 85.0 Ni.sub.0.74Ta.sub.0.22Yb.sub.0.04O.sub.x 50.7
17.8 84.2 17.5 84.6 Ni.sub.0.65Ta.sub.0.36Bi.sub.0.01O.sub.x 50.4
16.3 82.6 15.3 82.1 108.24 189.3 207.98 C S C S C S Library # (%)
(%) (%) (%) (%) (%) Table 26B, Part B1
Ni.sub.0.86Ta.sub.0.14O.sub.x 17.0 83.2 17.4 83.1 18.0 83.1
Ni.sub.0.65Ta.sub.0.31Ce.sub.0.04O.sub.x 17.8 82.5 16.6 82.0 17.8
82.1 Ni.sub.0.62Nb.sub.0.19Ta.sub.0.19Ce.sub.0.01O.sub.x 13.3 84.6
11.8 84.2 12.8 84.6 Ni.sub.0.73Ta.sub.0.24Dy.sub.0.03O.sub.x 18.4
84.2 18.0 84.0 18.7 84.2 Ni.sub.0.68Nb.sub.0.25Dy.sub.0.07O.sub.x
18.1 83.5 17.6 82.9 18.1 82.9
Ni.sub.0.68Nb.sub.0.26Er.sub.0.06O.sub.x 17.9 83.0 17.2 82.4 18.2
82.3 Blank 0.1 48.3 0.1 44.1 0.1 45.3 Ni.sub.0.62Nb.sub.0.38O.sub.x
17.5 85.1 16.3 84.7 16.9 84.9
Ni.sub.0.71Ta.sub.0.23Nd.sub.0.06O.sub.x 16.4 81.4 16.3 81.4 16.7
81.3 Ni.sub.0.63Nb.sub.0.34Sm.sub.0.03O.sub.x 19.4 85.0 18.8 84.5
17.3 84.5 Ni.sub.0.54Ta.sub.0.45Sm.sub.0.01O.sub.x 15.3 83.9 14.5
83.5 14.8 83.6 Ni.sub.0.72Ti.sub.0.28O.sub.x 17.7 85.2 17.4 85.1
17.4 85.0 Ni.sub.0.66Ti.sub.0.29Yb.sub.0.5O.sub.x 17.0 80.5 16.5
79.1 15.6 79.0 blank 0.1 43.8 0.1 42.2 0.1 39.9
Ni.sub.0.62Nb.sub.0.34Ce.sub.0.04O.sub.x 14.7 81.6 14.5 81.5 14.4
81.5 Ni.sub.0.62Ta.sub.0.34Ce.sub.0.04O.sub.x 13.9 82.3 13.2 82.2
12.7 82.1 Ni.sub.0.76Nb.sub.0.17Er.sub.0.06O.sub.x 11.4 84.5 11.5
84.3 11.4 84.2 Ni.sub.0.68Ta.sub.0.25Dy.sub.0.07O.sub.x 11.8 82.7
11.7 82.3 11.8 82.4
Ni.sub.0.60Nb.sub.0.19Ta.sub.0.18Sm.sub.0.03O.sub.x 14.1 82.8 13.7
82.2 13.7 82.4 Ni.sub.0.64Nb.sub.0.34Pr.sub.0.02O.s- ub.x 13.7 82.9
12.7 81.0 12.8 81.4 blank 0.1 44.0 0.1 43.2 0.1 44.8
Ni.sub.0.63Nb.sub.0.37O.sub.x 10.4 86.1 9.9 85.3 10.1 85.6
Ni.sub.0.51Ta.sub.0.42Zr.sub.0.07O.sub.x 12.9 82.3 12.5 82.0 12.6
82.1 Ni.sub.0.73Ti.sub.0.27O.sub.x 10.6 83.7 10.1 83.7 9.6 83.6
Ni.sub.0.58Ta.sub.0.34Gd.sub.0.07O.sub.x 9.0 83.1 8.5 82.5 8.5 82.7
Ni.sub.0.68Nb.sub.0.24Gd.sub.0.08O.sub.x 12.5 76.5 11.6 74.0 11.7
74.6 Ni.sub.0.80Nb.sub.0.19Sb.sub.0.01O.sub.x 11.9 85.5 11.2 85.0
11.1 85.3 Table 26B, Part B2 blank 0.1 40.0 0.1 40.6 0.1 41.1
Ni.sub.0.82Nb.sub.0.14Sb.sub.0.04O.sub.x 9.5 82.3 8.6 81.0 8.9 81.7
Ni.sub.0.60Nb.sub.0.39Sb.sub.0.01O.sub.x 16.0 83.4 15.4 82.9 15.5
83.2 Ni.sub.0.72Nb.sub.0.27Bi.sub.0.01O.sub.x 14.4 85.9 13.6 85.2
14.1 85.5 Ni.sub.0.73Ta.sub.0.25Bi.sub.0.02O.sub.x 9.8 85.7 8.9
85.5 9.3 85.7 Ni.sub.0.63Nb.sub.0.33Yb.sub.0.04O.sub.x 12.6 82.2
10.8 80.4 12.0 81.3 Ni.sub.0.59Ta.sub.0.37Yb.sub.0.04O.sub.x 6.2
85.1 5.4 85.0 5.9 85.0 blank 0.1 48.6 0.1 47.5 0.1 47.1
Ni.sub.0.65Nb.sub.0.33Ce.sub.0.02O.sub.x 14.6 78.1 12.7 72.3 13.5
73.6 Ni.sub.0.71Nb.sub.0.27Sb.sub.0.02O.sub.x 14.2 73.4 11.4 62.3
12.3 64.8 Ni.sub.0.65Nb.sub.0.33Ce.sub.0.02O.sub.x 12.4 78.4 10.2
70.3 10.8 73.1 Ni.sub.0.63Nb.sub.0.19Ta.sub.0.18O.sub.x/TiO.sub.2
6.1 89.0 4.9 89.2 5.3 89.2 Ni.sub.0.71Nb.sub.0.27Sb.sub.0.02O.sub.x
9.6 76.8 7.9 71.4 8.8 74.1 Ni.sub.0.65Nb.sub.0.33Ce.sub.0.02O.sub.-
x 17.0 85.6 16.0 85.4 17.6 85.9 blank 0.1 47.9 0.1 47.3 0.1 47.8
Ni.sub.0.74Nb.sub.0.08Ta.sub.0.17Ce.sub.0.01O.sub.x 15.7 84.7 15.3
84.3 15.5 84.2 Ni.sub.0.75Nb.sub.0.24Ce.sub.0.01O.sub.x 18.6 86.3
18.2 86.1 18.4 86.3 Ni.sub.0.53Ta.sub.0.40Gd.sub.0.07O.sub.x 16.1
77.3 14.7 74.4 15.0 75.2 Ni.sub.0.74Nb.sub.0.08Ta.sub.0.17Ce.sub.0-
.01O.sub.x 16.0 85.3 14.3 84.8 14.8 83.5
1Ni.sub.0.74Ta.sub.0.22Yb.- sub.0.04O.sub.x 17.8 85.1 16.6 84.7
17.4 84.9 Ni.sub.0.65Ta.sub.0.36Bi.sub.0.01O.sub.x 14.9 82.9 12.6
83.0 14.4 83.7
[0253] 400 Hour Lifetime Test
[0254] In the 400 hour lifetime test, forty-eight different Ni(Nb,
Ta, Ti)(Sm, Sn, Co, Cs, Sb, Ag)(Mg, Ca, Li) oxide catalysts were
prepared by precipitation using the metal salt precursors
substantially as described in earlier examples herein. The various
catalyst compositions, post-precipitation treatment (if any) and
calcination conditions are indicated in Table 26C.
[0255] The forty-eight catalysts of Table 26C (.about.50 mg) were
screened simultanteously in the 48-channel parallel fixed bed
reactor for oxidative ethane dehydrogenation at 275.degree. C. with
ethane:oxygen flow of 0.42:0.033 seem. Table 26D summarizes the
amount of catalyst screened, as well as the ethane conversion (C)
and ethylene selectivity (S) for each of the catalysts, measured
after various times during the test. These data show that, after 48
hours on stream, the 48 catalysts lost, on average, less than about
13% in conversion and less than about 2% in selectivity. Several of
the catalysts had no substantial loss of activity or selectivity
over the 400 hour test. FIGS. 2A and 2B show ethane conversion and
ethylene selectivity data versus time on stream during the 400%
hour lifetime test for Ni.sub.0.75Ta.sub.0.28Sn.sub.0.03O- .sub.x
(FIG. 2A) and Ni.sub.0.71Nb.sub.0.27Co.sub.0.02O.sub.x (FIG.
2B).
61TABLE 26C Catalyst composition, library reference #, and
preparation methods for catalysts screened in 400 hour lifetime
test. Library # Composition Remarks* Table 26C, Part A (1, 1)
16693.1A Ni.sub.0.68Nb.sub.0.10Ti.-
sub.0.10Ta.sub.0.10Sm.sub.0.02O.sub.x 5/320/8/air (1, 2) 16693.1B
Ni.sub.0.68Nb.sub.0.10Ti.sub.0.10Ta.sub.0.10Sm.sub.0.02O.sub.x PGS,
>300 .mu.m (1, 3) 16693.1C Ni.sub.0.68Nb.sub.0.10Ti.sub.0.10Ta.-
sub.0.10Sm.sub.0.02O.sub.x PGS, > 150 < 300 .mu.m (1, 4)
16693.2 Ni.sub.0.68Nb.sub.0.10Ti.sub.0.10Ta.sub.0.10Sm.sub.0.02O.s-
ub.x 5/320/8/N.sub.2 (1, 5) 16693.3
Ni.sub.0.68Nb.sub.0.10Ti.sub.0.- 10Ta.sub.0.10Sm.sub.0.02O.sub.x
5/320/8/air& 5/320/8/H.sub.2/Ar (1, 6) 16693.4
Ni.sub.0.68Nb.sub.0.10Ti.sub.0.10Ta.sub.0.10Sm.sub.- 0.02O.sub.x
5/320/8/H.sub.2/Ar (2, 1) 16693.5
Ni.sub.0.68Nb.sub.0.10Ti.sub.0.10Ta.sub.0.10Sm.sub.0.02O.sub.x
5/320/8/N.sub.2& 5/320/8/air (2, 2) 16693.6
Ni.sub.0.68Nb.sub.0.10Ti.sub.0.10Ta.sub.0.10Sm.sub.0.02O.sub.x
5/320/8/H.sub.2/Ar& 5/320/8/air (2, 3) 16777.31
Ni.sub.0.75Nb.sub.0.25O.sub.x 5/320/8/air (2, 4) 16777.14
Ni.sub.0.66Nb.sub.0.34O.sub.x 5/320/8/air (2, 5) 16777.35
Ni.sub.0.71Nb.sub.0.26Sm.sub.0.03O.sub.x 5/320/8/air (2, 6)
16777.53 Ni.sub.0.71Nb.sub.0.26Sm.sub.0.03O.sub.x 5/320/8/air (3,
1) 16467.54 Ni.sub.0.67Nb.sub.0.32Sn.sub.0.01O.sub.x 5/320/8/air
(3, 2) 16469.52 Ni.sub.0.75Ta.sub.0.28Sn.sub.0.03O.sub.x
5/320/8/air (3, 3) 16469.64
Ni.sub.0.62Ta.sub.0.37Sn.sub.0.01O.sub.x 5/320/8/air (3, 4)
16505.53 Ni.sub.0.75Zr.sub.0.23Sn.sub.0.02O.sub.x 5/320/8/air (3,
5) 16470.31 Ni.sub.0.85Ti.sub.0.13Sn.sub.0.02O.sub.x 5/320/8/air
(3, 6) 16470.53 Ni.sub.0.67Ti.sub.0.31Sn.sub.0.02O.sub- .x
5/320/8/air (4, 1) 16470.63 Ni.sub.0.65Ti.sub.0.32Sn.sub.0.03O.s-
ub.x 5/320/8/air (4, 2) 16650.14A
Ni.sub.0.68Nb.sub.0.10Ti.sub.0.10- Ta.sub.0.10Sm.sub.0.02O.sub.x
5/320/8/air (4, 3) 16650.14B
Ni.sub.0.68Nb.sub.0.10Ti.sub.0.10Ta.sub.0.10Sm.sub.0.02O.sub.x
5/320/8/air (4, 4) 16650.42 Ni.sub.0.68Nb.sub.0.10Ti.sub.0.10Ta.su-
b.0.10Sm.sub.0.02O.sub.x 5/320/8/air (4, 5) 11525
Ni.sub.0.63Nb.sub.0.19Ta.sub.0.18O.sub.x 5/400/8/air (4, 6) 16610.3
Ni.sub.0.63Nb.sub.0.19Ta.sub.0.18O.sub.x 5/320/8/N.sub.2 (5, 1)
16365.31 Ni.sub.0.85Nb.sub.0.14Co.sub.0.01O.sub.x 5/320/8/air (5,
2) 16365.42 Ni.sub.0.78Nb.sub.0.20Co.sub.0.02O.sub.x 5/320/8/air
(5, 3) 16365.53 Ni.sub.0.71Nb.sub.0.27Co.sub.0.02O.sub.x
5/320/8/air (5, 4) 16298.11
Ni.sub.0.75Nb.sub.0.22Sm.sub.0.03O.sub.x 5/320/8/air (5, 5)
16298.13 Ni.sub.0.74Nb.sub.0.21Sm.sub.0.03Cs.su- b.0.02O.sub.x
5/320/8/air (5, 6) 16298.41 Ni.sub.0.75Nb.sub.0.21Sm.-
sub.0.03Sb.sub.0.01O.sub.x 5/320/8/air (6, 1) 16298.42
Ni.sub.0.74Nb.sub.0.21Sm.sub.0.03Sb.sub.0.02O.sub.x 5/320/8/air (6,
2) 16298.71 Ni.sub.0.74Nb.sub.0.21Ti.sub.0.02Sm.sub.0.03O.sub.x
5/320/8/air (6, 3) 16297.11 Ni.sub.0.67Ti.sub.0.30Sm.sub.0.03O.sub-
.x 5/320/8/air (6, 4) 16297.21
Ni.sub.0.66Ti.sub.0.30Sm.sub.0.03Mg.- sub.0.01O.sub.x 5/320/8/air
Table 26C, Part B (6, 5) 16297.24
Ni.sub.0.64Ti.sub.0.30Sm.sub.0.03Mg.sub.0.03O.sub.x 5/320/8/air (6,
6) 16297.33 Ni.sub.0.65Ti.sub.0.30Sm.sub.0.03Ca.sub.0.02O.sub.- x
5/320/8/air (7, 1) 16297.83 Ni.sub.0.62Ti.sub.0.28Ta.sub.0.07Sm.s-
ub.0.03O.sub.x 5/320/8/air (7, 2) 16160.14
Ni.sub.0.51Nb.sub.0.14Ti- .sub.0.19Ta.sub.0.15O.sub.x 5/320/8/air
(7, 3) 16160.43 Ni.sub.0.58Nb.sub.0.15Ti.sub.0.11Ta.sub.0.16O.sub.x
5/320/8/air (7, 4) 16790.13
Ni.sub.0.55Ta.sub.0.44Ag.sub.0.01O.sub.x 5/320/8/air (7, 5)
16790.23 Ni.sub.0.63Ta.sub.0.36Ag.sub.0.01O.sub.x 5/320/8/air (7,
6) 16790.36 Ni.sub.0.71Ti.sub.0.28Ag.sub.0.01O.sub.x 5/320/8/air
(8, 1) 16685.32 Ni.sub.0.60Ta.sub.0.38Co.sub.0.02O.sub.x
5/320/8/air (8, 2) 16687.33 Ni.sub.0.66Ti.sub.0.33Co.sub.0.01O.sub-
.x 5/320/8/air (8, 3) 16687.43
Ni.sub.0.65Ti.sub.0.33Co.sub.0.02O.s- ub.x 5/320/8/air (8, 4)
16828.14 Ni.sub.0.71Nb.sub.0.27Co.sub.0.02O- .sub.x 5/320/8/air (8,
5) 16828.34 Ni.sub.0.70Nb.sub.0.27Co.sub.0.0- 2Li.sub.0.01O.sub.x
5/320/8/air (8, 6) 16828.62
Ni.sub.0.77Nb.sub.0.20Co.sub.0.02Mg.sub.0.01O.sub.x 5/320/8/air
*Calcination conditions = ramp rate (.degree.
C./min)/level(.degree. C.)/dwell time(h)/environment. *PGS =
pressed, ground and sieved.
[0256]
62TABLE 26D Catalyst library reference #, sample mass (mg) and
ethane conversion (C) and ethylene selectivity (S) measured at
various times on stream during screening in 400 hour lifetime test.
Time on stream (hour) 0.9 4.9 167.4 248.8 406.2 Mass C S C S C S C
S C S Library # (mg) (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) Table
26D, Part A 16693.1 50.2 13.1 89.3 12.8 89.5 10.9 88.9 10.7 88.1
11.8 87.0 16693.1 51.2 14.0 90.1 13.9 90.5 12.2 90.1 12.1 89.0 13.1
88.4 16693.1 50.8 14.1 90.2 14.2 90.3 12.7 90.2 12.4 89.0 13.2 87.7
16693.2 50.9 4.9 0.2 13.0 62.6 12.5 87.7 12.3 86.3 9.9 85.9 16693.3
51.0 12.0 86.7 13.4 89.1 11.8 88.3 11.6 87.1 12.0 86.5 16693.4 50.0
7.8 64.1 10.9 84.6 9.4 86.6 9.2 85.1 9.7 83.2 16693.5 50.4 12.9
90.0 12.6 89.4 11.2 88.2 10.4 87.5 11.3 85.8 16693.6 49.8 11.5 87.9
9.1 87.3 9.0 85.2 8.7 84.3 9.2 82.9 16777.31 48.0 14.2 90.1 14.2
90.2 12.9 90.2 12.7 89.7 13.4 88.4 16777.14 53.6 15.0 90.6 15.0
90.9 13.0 89.4 12.6 88.7 11.8 88.3 16777.35 50.7 14.3 90.3 14.3
90.5 12.8 89.7 12.4 89.2 12.9 88.3 16777.53 48.0 14.8 90.5 14.5
90.6 12.7 89.8 12.4 89.0 13.0 87.4 16467.54 50.0 14.7 91.9 14.9
92.0 13.1 90.8 12.2 90.2 12.1 88.8 16469.52 52.0 15.5 92.1 15.0
91.9 14.1 92.1 14.1 91.9 15.1 91.7 16469.64 48.0 15.9 92.6 15.9
92.6 12.9 92.1 12.4 91.7 12.5 90.7 16505.53 52.6 12.8 86.5 12.7
86.3 11.3 84.4 9.9 83.8 9.3 83.3 Table 26D, Part B 16470.31 51.0
13.2 87.8 12.9 87.4 11.0 85.3 10.6 84.8 11.1 84.3 16470.53 48.7
16.1 92.6 15.5 92.7 14.6 92.7 14.6 92.5 11.4 91.8 16470.63 51.0
15.4 92.3 15.6 92.4 13.5 92.2 13.8 91.9 13.8 90.7 16650.14 49.1
14.4 90.8 14.0 90.8 12.1 89.2 11.7 88.4 12.1 87.4 16650.14 22.5
11.3 88.9 11.0 88.5 8.7 86.5 8.3 85.6 8.5 84.0 16650.42 54.8 14.9
90.3 14.6 90.6 11.9 89.7 10.7 89.0 12.3 88.4 11525 54.3 5.7 86.8
5.7 87.1 5.0 86.3 4.8 85.5 4.7 84.9 16610.3 52.0 15.4 91.5 14.8
91.9 12.2 91.6 12.3 91.1 10.4 89.9 16365.31 50.0 14.9 91.8 14.8
91.9 13.4 92.5 13.8 92.6 14.4 91.9 16365.42 50.2 15.1 91.7 15.2
91.9 14.6 92.5 14.6 92.3 15.5 91.9 16365.53 49.8 15.3 91.4 15.5
91.5 14.5 92.0 14.6 91.6 15.2 90.4 16298.11 50.4 15.1 90.9 14.7
90.9 13.3 90.7 12.3 90.4 12.9 89.6 16298.13 50.0 15.3 91.3 15.2
91.3 14.2 91.1 14.2 91.0 14.5 90.4 16298.41 50.1 14.8 91.4 13.7
91.3 12.8 91.3 10.3 90.8 10.2 92.4 16298.42 49.8 15.5 92.3 15.3
92.4 13.6 92.9 14.0 92.5 14.2 91.6 16298.71 50.4 14.6 90.8 14.7
90.9 13.5 90.3 12.6 89.6 13.8 88.3 16297.11 49.6 14.2 91.8 15.7
91.9 14.0 91.8 14.2 91.3 14.5 90.0 16297.21 49.6 15.7 91.7 15.4
91.9 13.8 91.4 13.1 91.0 12.8 90.3 16297.24 49.7 15.5 91.7 15.3
91.9 14.0 91.2 13.8 90.8 13.9 89.9 16297.33 49.9 15.8 91.4 15.4
91.4 13.5 91.4 12.9 91.0 12.7 91.5 16297.83 49.6 15.8 91.1 15.2
91.5 12.9 91.0 13.1 90.3 12.9 88.5 16160.14 49.9 15.0 92.1 15.0
92.2 11.6 90.4 10.4 89.8 10.9 88.7 16160.43 50.1 15.0 92.1 13.7
92.0 11.6 90.4 11.4 89.9 11.4 88.6 16790.13 50.0 14.7 91.6 14.4
91.7 11.6 90.3 11.3 90.0 11.3 89.6 16790.23 50.2 14.8 91.8 14.4
91.9 11.2 90.6 11.0 90.5 10.8 90.0 16790.36 50.2 15.2 90.8 14.8
91.2 12.5 90.4 12.6 91.2 12.2 90.3 16685.32 49.9 14.3 91.3 14.2
91.4 11.0 90.5 10.5 89.8 9.8 88.4 16687.33 49.5 13.5 91.0 15.2 91.2
13.9 90.5 12.8 89.9 13.7 88.3 16687.43 49.9 15.1 90.9 15.1 91.3
14.0 90.9 13.7 90.3 14.0 88.6 16828.14 50.2 15.1 90.5 15.0 90.8
13.8 90.9 13.5 90.6 13.9 89.8 16828.34 49.7 15.0 90.0 14.9 90.3
13.5 89.1 13.3 88.3 13.3 86.9 16828.62 50.6 14.8 91.2 14.0 91.4
13.3 91.7 12.8 91.9 13.6 91.7
Example 27
ODHE Over Ni(Nb, Ta, Ti, Zr)(Ce, Dy, Er, Nd, Sm, Yb, Pr, Gd, Sb,
Bi) Oxide Catalysts with Ethylene Co-Feed
[0257] Catalyst compositions comprising various Ni(Nb, Ta, Ti,
Zr)(Ce, Dy, Er, Nd, Sm, Yb, Pr, Gd, Sb, Bi) oxides were prepared as
described in connection with Example 26 (see Table 26A), and
screened in the parallel fixed bed reactor for oxidative
dehydrogenation with an ethane and ethylene cofeed. Specifically,
these catalysts were screened at 300.degree. C. with an ethane
(49.5%) and ethylene (50.5%) mixed feed at a ratio of
ethane/ethylene mixed feed:nitrogen:oxygen was 0.42:0.54:0.088
sccm.
[0258] Table 27A shows the catalyst compositions, the sample mass
thereof screened, the amount of ethane loss/ethylene gain resulting
from the reaction, and the calculated ethylene selectivity of the
reaction. These data demonstrate that the oxydehydrogenation
activity of the catalysts are not substantially product inhibited,
and that ethane dehyrogenation can be effected using feed streams
having .about.50% ethylene product.
63TABLE 27A Ethane loss, ethylene gain and ethylene selectivity for
a mixed feed (ethane (49.5%) and ethylene (50.5%)) screen in the
parallel fixed bed reactors. Test condition:
(C.sub.2H.sub.4/C.sub.2H.sub.6):N.sub.2:O.sub.2 flow of
0.42:0.54:0.088 sccm at 300.degree. C. Ethylene Ethane Ethylene
Mass Gain loss Selectivity Catalyst (mg) (%) (%) (%) Table 27 A,
Part A 1 Ni.sub.0.86Ta.sub.0.14O.sub.x 49.4 5.6 -7.9 59.9 2
Ni.sub.0.65Ta.sub.0.31Ce.sub.0.04O.sub.x 50.0 2.5 -5.8 38.0 3
Ni.sub.0.62Nb.sub.0.19Ta.sub.0.19Ce.sub.0.01O.sub.- x 50.4 0.4 -3.3
11.4 4 Ni.sub.0.73Ta.sub.0.24Dy.sub.0.03O.sub.x 50.5 0.5 -3.8 10.7
5 Ni.sub.0.68Nb.sub.0.25Dy.sub.0.07O.sub.x 49.8 2.0 -5.0 35.0 6
Ni.sub.0.68Nb.sub.0.26Er.sub.0.06O.sub.x 49.8 2.8 -5.8 42.3 7 Blank
1.0 2.1 -1.8 * 8 Ni.sub.0.62Nb.sub.0.38O.- sub.x 49.2 3.2 -6.0 46.0
9 Ni.sub.0.71Ta.sub.0.23Nd.sub.0.06O.sub.x 49.6 0.8 -4.0 16.9 10
Ni.sub.0.63Nb.sub.0.34Sm.sub.0.03O.sub.x 50.4 1.0 -4.5 19.9 11
Ni.sub.0.54Ta.sub.0.45Sm.sub.0.01O.sub.x 49.5 2.0 -4.6 38.0 12
Ni.sub.0.72Ti.sub.0.28O.sub.x 50.0 2.7 -5.5 43.5 13
Ni.sub.0.66Ti.sub.0.29Yb.sub.0.05O.sub.x 49.5 5.0 -7.3 58.5 14
blank 1.0 0.8 -0.7 * 15 Ni.sub.0.62Nb.sub.0.34Ce.su- b.0.04O.sub.x
42.6 -0.7 -2.9 0.0 16 Ni.sub.0.62Ta.sub.0.34Ce.sub.0.- 04O.sub.x
47.6 -0.9 -2.5 0.0 17 Ni.sub.0.76Nb.sub.0.17Er.sub.0.06O.- sub.x
45.0 1.0 -3.1 27.3 18 Ni.sub.0.68Ta.sub.0.25Dy.sub.0.07O.sub.- x
44.2 2.1 -4.0 45.4 19 Ni.sub.0.60Nb.sub.0.19Ta.sub.0.18Sm.sub.0.0-
3O.sub.x 45.6 5.3 -6.9 64.7 20
Ni.sub.0.64Nb.sub.0.34Pr.sub.0.02O.s- ub.x 48.1 2.7 -5.0 46.8 21
blank 1.0 -1.0 0.8 * 22 Ni.sub.0.63Nb.sub.0.37O.sub.x 45.9 -0.2
-1.9 0.0 23 Ni.sub.0.51Ta.sub.0.42Zr.sub.0.07O.sub.x 44.5 2.5 -4.6
46.4 24 Ni.sub.0.73Ti.sub.0.27O.sub.x 45.8 1.3 -3.4 34.6 25
Ni.sub.0.58Ta.sub.0.34Gd.sub.0.07O.sub.x 45.6 3.7 -4.9 65.2 26
Ni.sub.0.68Nb.sub.0.24Gd.sub.0.08O.sub.x 55.2 2.7 -4.9 47.5 27
Ni.sub.0.80Nb.sub.0.19Sb.sub.0.01O.sub.x 48.6 0.6 -2.8 19.9 Table
27A, Part B 28 blank 1.0 -1.5 1.3 * 29
Ni.sub.0.82Nb.sub.0.14Sb.sub.0.04O.sub.x 49.6 1.5 -3.2 40.9 30
Ni.sub.0.60Nb.sub.0.39Sb.sub.0.01O.sub.x 51.8 2.4 -5.2 40.5 31
Ni.sub.0.72Nb.sub.0.27Bi.sub.0.01O.sub.x 54.7 5.1 -6.8 63.6 32
Ni.sub.0.73Ta.sub.0.25Bi.sub.0.02O.sub.x 50.0 1.9 -3.5 47.9 33
Ni.sub.0.63Nb.sub.0.33Yb.sub.0.04O.sub.x 41.1 0.5 -3.0 14.5 34
Ni.sub.0.59Ta.sub.0.37Yb.sub.0.04O.sub.x 47.1 -0.7 -1.2 0.0 35
blank 1.0 -0.4 0.3 * 36 Ni.sub.0.65Nb.sub.0.33Ce.sub.0.02O.sub.x
48.3 2.6 -5.1 44.1 37 Ni.sub.0.71Nb.sub.0.27Sb.sub.0.02O.sub.x 49.1
6.0 -8.0 64.1 38 Ni.sub.0.65Nb.sub.0.33Ce.sub.0.02O.sub.x 49.3 2.7
-4.8 49.3 39 Ni.sub.0.63Nb.sub.0.19Ta.sub.0.18O.sub.x/TiO- .sub.2
145.9 -1.0 -0.8 0.0 40 Ni.sub.0.71Nb.sub.0.27Sb.sub.0.02O.su- b.x
51.5 -0.1 -2.0 0.0 41 Ni.sub.0.65Nb.sub.0.33Ce.sub.0.02O.sub.x 49.7
2.3 -4.9 41.1 42 blank 1.0 -0.1 0.1 * 43
Ni.sub.0.74Nb.sub.0.08Ta.sub.0.17Ce.sub.0.01O.sub.x 50.0 5.0 -7.2
59.3 44 Ni.sub.0.75Nb.sub.0.24Ce.sub.0.01O.sub.x 50.2 3.2 -6.1 46.1
45 Ni.sub.0.53Ta.sub.0.40Gd.sub.0.07O.sub.x 48.9 0.6 -4.2 13.3 46
Ni.sub.0.74Nb.sub.0.08Ta.sub.0.17Ce.sub.0.01O.sub.x 50.9 0.3 -3.5
8.9 47 Ni.sub.0.74Ta.sub.0.22Yb.sub.0.04O.sub.x 50.7 2.1 -5.1 35.6
48 Ni.sub.0.65Ta.sub.0.36Bi.sub.0.01O.sub.x 50.4 2.3 -4.9 41.1
Example 28
ODHE Over NiNbTa Oxide Catalyst with Multi-Stage Fixed Bed Reactor
and Multiple Oxygen Feed
[0259] A NiNbTa oxide catalyst,
Ni.sub.0.63Nb.sub.0.19Ta.sub.0.18O.sub.x, prepared from nickel
nitrate, niobium oxalate and tantalum oxalate by precipitation with
tetramethylammonium hydroxide and with a maximum calcination
temperature of 320.degree. C. was screened in a three-stage fixed
bed reactor having multiple oxygen feeds, substantially as shown
and described in connection with FIG. 1B.
[0260] Briefly, about 50 mg of the catalyst was loaded into each of
the reactor stages. Ethane, oxygen and nitrogen were fed as initial
feed to the first stage of the multi-stage reactor, wherein ethane
was oxidatively dehydrogenated to form ethylene. The exhaust from
the first stage was fed to the second stage, together with
additional oxygen and nitrogen feed, and further oxidative
dehydrogenation of ethane was effected in the second stage.
Similarly, exhaust from the second stage was fed to the third
stage, together with additional oxygen and nitrogen feed, and
further oxidative dehydrogenation of ethane was effected in the
third stage. The reaction exhaust from the third stage was analyzed
by gas chromatograph.
[0261] Nine different experimental cases were considered with
variations in (1) the relative flowrates of nitrogen:oxygen:ethane
in the initial (first-stage) feed, (2) the relative flowrates of
nitrogen:oxygen used as additional feed in the second and third
stages, and/or (3) the reaction temperatures of the three reaction
zones (300.degree. C. or 275.degree. C.).
[0262] For comparison, the NiNbTa oxide catalyst was also screened,
in each of the nine experimental cases, under similar reaction
conditions in a single-stage, single-feed fixed bed reactor,
substantially as shown and described in connection with FIG.
1A.
[0263] Table 28A shows the reaction temperature, amount of
catalyst, initial feed rates (sccm of nitrogen:oxygen:ethane),
additional feed rates (sccm of nitrogen:ethane), and performance
data (conversion, selectivity) for each of the nine different
experimental cases shows--for the multi-stage reactor and the
single-stage reactor configurations. These data demonstrate that
overall ethane conversion can be substantially improved (c.g., C of
not less than about 30% C, and ranging from about 30% to about 45%)
while maintaining relatively high ethylene selectivities (e.g., S
of not less than about 70% S, and ranging from about 70% to about
85%).
64TABLE 28A Ethane conversion and ethylene selectivity for
Ni.sub.0.63Nb.sub.0.19Ta.sub.0.18O.sub.x in multi-stage and
single-stage reactor configurations at various relative flowrates
and temperatures. Initial feed addition feed Reactor Reaction mass
N2:O2:C2H6 N2:O2 Configuration T ( C) (mg) (sccm) (sccm) C(%) S(%)
Table 28A, Part A SF 300 C. 52.9 0.32:0.088:0.42 n/a 18.2 85.4 Case
MF1 300 C. 51.6 0.32:0.088:0.42 I MF2 300 C. 49.0 0.32:0.088 MF3
300 C. 51.4 0.32:0.088 33.6 74.5 SF 300 C. 52.9 0.25:0.066:0.42 n/a
17.4 87.7 Case MF1 300 C. 51.6 0.25:0.066:0.42 II MF2 300 C. 49.0
0.25:0.066 MF3 300 C. 51.4 0.25:0.066 32.0 76.9 SF 300 C. 52.9
0.16:0.044:0.42 n/a 16.5 90.8 Table 28A, Part B Case MF1 300 C.
51.6 0.16:0.044:0.42 III MF2 300 C. 49.0 0.16:0.044 MF3 300 C. 51.4
0.16:0.044 31.1 81.3 SF 300 C. 52.9 0.082:0.022:0.42 n/a 11.4 93.6
Case MF1 300 C. 51.6 0.082:0.022:0.42 IV MF2 300 C. 49.0
0.082:0.022 MF3 300 C. 51.4 0.082:0.022 26.1 85.8 SF 300 C. 52.9
0.16:0.044:0.208 n/a 22.0 85.9 Case MF1 300 C. 51.6
0.16:0.044:0.208 V MF2 300 C. 49.0 0.16:0.044 MF3 300 C. 51.4
0.16:0.044 44.6 73.9 SF 300 C. 52.9 0.082:0.022:0.208 n/a 18.2 91.2
Case MF1 300 C. 51.6 0.082:0.022:0.208 VI MF2 300 C. 49.0
0.082:0.022 MF3 300 C. 51.4 0.082:0.022 39.3 78.4 SF 300 C. 52.9
0.041:0.011:0.208 n/a 12.1 89.9 Case MF1 300 C. 51.6
0.041:0.011:0.208 VII MF2 300 C. 49.0 0.041:0.011 MF3 300 C. 51.4
0.041:0.011 29.0 84.8 SF 275 C. 52.9 0.206:0.055:1.04 n/a 7.6 93.1
Case MF1 275 C. 51.6 0.206:0.055:1.04 VIII MF2 275 C. 49.0
0.206:0.055 MF3 275 C. 51.4 0.206:0.055 15.8 86.7 SF 275 C. 52.9
0.082:0.022:0.42 n/a 10.7 93.7 Case MF1 275 C. 51.6
0.082:0.022:0.42 IX MF2 275 C. 49.0 0.079:0.021 MF3 275 C. 51.4
0.079:0.021 23.2 86.0 SF = single feed; MF1 = multi-feed, 1.sup.st
stage; MF2 = multifeed, 2.sup.nd stage; MF3 = multifeed, 3.sup.rd
stage; C = ethane conversion; S = ethylene selectivity.
[0264] In light of the detailed description of the invention and
the examples presented above, it can be appreciated that the
several objects of the invention are achieved.
[0265] The explanations and illustrations presented herein are
intended to acquaint others skilled in the art with the invention,
its principles, and its practical application. Those skilled in the
art may adapt and apply the invention in its numerous forms, as may
be best suited to the requirements of a particular use.
Accordingly, the specific embodiments of the present invention as
set forth are not intended as being exhaustive or limiting of the
invention.
* * * * *