U.S. patent application number 12/796269 was filed with the patent office on 2010-09-30 for lightly branched higher olefin oligomerization with surface modified zeolite catalyst.
This patent application is currently assigned to ExxonMobil Research and Engineering Company. Invention is credited to John S. Buchanan, Jane C. Cheng, Jennifer S. Feeley, Sal Miseo, Stuart L. Soled.
Application Number | 20100248944 12/796269 |
Document ID | / |
Family ID | 40523848 |
Filed Date | 2010-09-30 |
United States Patent
Application |
20100248944 |
Kind Code |
A1 |
Cheng; Jane C. ; et
al. |
September 30, 2010 |
Lightly Branched Higher Olefin Oligomerization with Surface
Modified Zeolite Catalyst
Abstract
A substantially surface-deactivated catalyst composition that is
stable at least to 300.degree. C. The catalyst includes a zeolite
catalyst (e.g., ZSM-22, ZSM-23, or ZSM-57) having active internal
Bronsted acid sites and a surface-deactivating amount of a rare
earth or yttrium oxide (e.g., chosen from lanthanum oxide or
lanthanides oxide). This to catalyst is preferably used in a
process for producing a higher olefin by oligomerizing a light
olefin, wherein the process includes contacting a light olefin
under oligomerization conditions with the substantially
surface-deactivated catalyst composition.
Inventors: |
Cheng; Jane C.;
(Bridgewater, NJ) ; Miseo; Sal; (Pittstown,
NJ) ; Soled; Stuart L.; (Pittstown, NJ) ;
Buchanan; John S.; (Lambertville, NJ) ; Feeley;
Jennifer S.; (Lebanon, NJ) |
Correspondence
Address: |
ExxonMobil Research & Engineering Company
P.O. Box 900, 1545 Route 22 East
Annandale
NJ
08801-0900
US
|
Assignee: |
ExxonMobil Research and Engineering
Company
Annandale
NJ
|
Family ID: |
40523848 |
Appl. No.: |
12/796269 |
Filed: |
June 8, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11973101 |
Oct 5, 2007 |
7759533 |
|
|
12796269 |
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Current U.S.
Class: |
502/73 |
Current CPC
Class: |
B01J 29/7076 20130101;
B01J 2229/20 20130101; B01J 29/7092 20130101; B01J 2229/123
20130101; C07C 2/12 20130101; B01J 2229/42 20130101; B01J 2229/18
20130101; B01J 29/7096 20130101 |
Class at
Publication: |
502/73 |
International
Class: |
B01J 29/40 20060101
B01J029/40 |
Claims
1. A surface-deactivated catalyst composition comprising a zeolite
catalyst having active internal Bronsted acid sites and containing
a surface-deactivating amount of a rare earth or yttrium oxide, and
wherein the amount ranges from greater than 0.84 wt. % to less than
2.52 wt. %.
2. The catalyst composition according to claim 1, wherein said
catalyst composition is stable at least to 300.degree. C.
3. The catalyst composition according to claim 1, wherein said
zeolite catalyst is chosen from ZSM-22, ZSM-23, or ZSM-57.
4. The catalyst composition according to claim 1, wherein said rare
earth oxide is chosen from lanthanum oxide or lanthanides
oxide.
5. The catalyst composition according to claim 1, wherein said
zeolite catalyst is a 10-ring zeolite.
6-17. (canceled)
18. A method of making a surface-deactivated catalyst composition
comprising: a zeolite catalyst with a surface-deactivating amount
of a rare earth or yttrium oxide for rendering the surface of said
zeolite catalyst substantially inactive for acidic reaction, and
wherein the amount ranges from greater than 0.84 wt. % to less than
2.52 wt. %.
19. The method according to claim 18, wherein said substantially
surface-deactivated catalyst composition is stable at least to
300.degree. C.
20. The method according to claim 18, wherein said zeolite catalyst
is chosen from ZSM-22, ZSM-23, or ZSM-57.
21. The method according to claim 18, wherein said rare earth oxide
is chosen from lanthanum oxide or lanthanides oxide.
22. The method according to claim 20, wherein said zeolite catalyst
is a 10-ring zeolite.
Description
FIELD
[0001] The present disclosure generally relates to catalyst
compositions for the production of olefin derivatives, for example,
higher olefins, wherein the catalyst composition is a 10-ring
zeolite whose surface acidity has been modified by incipient
wetness treatment with an yttrium or rare earth oxide. The present
disclosure is useful in higher olefin production processes using
the compositions. This disclosure is useful in processes for higher
olefin production with reduced branching of the higher olefins. The
catalyst compositions typically comprise 10-ring zeolites with
alumina binder and high temperature stable modifiers that reduce
the surface acidity.
BACKGROUND
[0002] Solid acid catalysts have been used commercially for
oligomerization of olefinic feedstock. In an oligomerization
process monomers are converted to a finite degree of
polymerization. In processes using olefinic feedstock, light
olefins (C.sub.3.sup.= to C.sub.5.sup.=) are converted typically
into branched olefins in the C.sub.6-C.sub.15 range using solid
phosphoric acid catalyst (sPa). The sPa process was developed by
UOP in the 1930's. This process has a number of drawbacks: (1) low
catalyst life due to pellet disintegration causing reactor pressure
drop; (2) environmental waste handling problems; and (3)
operational and quality constraints limit flexible feedstock.
Previously it has been found that acidic zeolites with 10-ring
pores, such as ZSM-22, ZSM-23, and ZSM-57, are good alternative
catalysts for olefin oligomerization, wherein branched higher
olefins are produced from light olefins. These branched higher
olefins are further derivatized to branched (OXO) alcohols which in
turn are esterified to produce esters that are used as
plasticizers. Additionally, these branched higher olefins are
hydrogenated to produce desired hydrocarbon solvents. Further,
these lightly branched higher olefins are useful in alkylation of
benzene or phenol to produce sulfonate detergent precursors.
Zeolite technology offers several advantages compared with the
older sPa technology including ease of handling, higher catalytic
activity, improved product selectivity, and facile catalyst
regeneration capability.
[0003] U.S. Pat. No. 5,026,933 (Blain et al.) discloses the use of
10-member ring zeolites for higher olefin production. That is,
heavy distillate and lubricant range hydrocarbons can be
synthesized over ZSM-5 type catalysts at elevated temperature and
pressure to provide a product having substantially linear molecular
conformations due to the ellipsoidal shape of these catalysts.
Conversion of olefins to gasoline and/or distillate products is
disclosed in U.S. Pat. Nos. 3,960,978 and 4,021,502 (Givens, Plank
and Rosinski) wherein gaseous olefins in the range of ethylene to
pentene, either alone or in admixture with paraffins are converted
into an olefinic gasoline blending to stock by contacting the
olefins with a catalyst bed made up of a ZSM-5 type zeolite. Such a
technique has been developed by Garwood, et al, as disclosed in
European Patent Application No. 83301391.5, published 29 Sep. 1983.
In U.S. Pat. Nos. 4,150,062; 4,211,640; 4,227,992; and 4,547,613
Garwood, et al. disclose operating conditions for a process for
selective conversion of C.sub.3+ olefins to mainly aliphatic
hydrocarbons. In the process for catalytic conversion of olefins to
heavier hydrocarbons by catalytic oligomerization using a medium
pore shape selective acid crystalline zeolite, process conditions
can be varied to favor the formation of hydrocarbons of varying
molecular weight. At moderate temperature and relatively high
pressure, the conversion conditions favor C.sub.10+ aliphatic
product. Lower olefinic feedstocks containing C.sub.2-C.sub.8
alkenes may be converted; however, the distillate mode conditions
do not convert a major fraction of ethylene. A typical reactive
feedstock consists essentially of C.sub.3-C.sub.6 mono-olefins,
with varying amounts of non-reactive paraffins and the like being
acceptable components. One conventional process for producing
substantially linear hydrocarbons by oligomerizing a lower olefin
at elevated temperature and pressure comprises contacting the lower
olefin under polymerization conditions with siliceous acidic ZSM-23
zeolite having Bronsted acid activity; wherein the zeolite has
acidic pore activity and wherein the zeolite surface is rendered
substantially inactive for acidic reactions, the zeolite surface
being neutralized by a bulky trialkyl pyridine compound having an
effective cross-section larger than the zeolite pore.
[0004] Although higher olefins produced from zeolite-based
catalysts have lower branching than those made with sPa, it is
highly desirable to further reduce branching of higher olefin
product streams. It is known that collidine
(2,4,6-trimethylpyridine) is an effective agent to deactivate
surface acid sites of 10-ring zeolites, thus improving catalyst
selectivity toward production of less-branched higher olefin
products from olefin containing feedstocks. However, a drawback of
collidine is its tendency to desorb from the surface under reaction
olefin oligomerization conditions. Desorption is especially
troublesome if the oligomerization reaction temperature is higher
than 240.degree. C. For olefin oligomerization process, typical
commercial end of cycle temperature is about 250.degree. C.
[0005] Collidine co-boils with 1-decene and desorbed collidine
could contaminate higher olefin products and derivatives, such as
branched alcohols produced in a down-stream OXO process. In order
to maintain a constant level of collidine on zeolite, a continuous
co-feeding of collidine with feed olefin is required. Another
drawback of organic-based surface treatment is collindines
inability to survive air-regeneration of the spent catalyst. That
is, air regeneration burns off the organics, such as collidine. The
inorganic species (such as zeolites, yttria and La-oxide) remain
intact.
[0006] Accordingly, the composition of surface modified 10-ring
zeolite catalysts requires the control of the surface acidity of
the catalyst to enable a product higher olefin containing stream
with low branching levels per molecule. For example, one such
technique is to treat the 10-ring zeolite catalyst with an organic
base such as collidine. However, because the collidine modified
zeolite catalyst is not thermally stable at end of run
temperatures, there is leaching of collidine and potentially
contamination of the higher olefin containing product stream.
Moreover, the high temperature air regeneration of collidine
modified catalyst leads to decomposition of the collidine.
Therefore, collidine treatment has to be repeated after each air
regeneration before the catalyst can be used for higher olefin
production.
[0007] There is a continuing need for improvement in the catalyst
for olefin oligomerization reactions of the type described above.
In particular there is a need for effective surface modified
zeolite catalysts such that they are stable to end of run olefin
oligomerization temperature, do not leach an organic base into the
higher olefin product stream and are air regenerable.
[0008] The present disclosure provides a novel alternate catalyst
system for olefin oligomerization to lightly branched higher
olefins, stable to end of oligomerization reaction temperatures,
stable to air regeneration, and does not leach organic base to
contaminate the higher olefin product stream.
SUMMARY
[0009] A substantially surface-deactivated catalyst composition
comprising a zeolite catalyst having active internal Bronsted acid
sites and containing a surface-deactivating amount of a rare earth
or yttrium oxide. Preferably, the catalyst composition is stable at
least to about 300.degree. C. (i.e., air regeneration temperature
is generally between about 400 to about 540.degree. C.). The
catalyst composition preferably exhibits a substantially
deactivated surface acidity.
[0010] A process for producing a higher olefin by oligomerizing a
lower olefin, the process comprising: contacting the lower olefin
under oligomerization conditions with a substantially
surface-deactivated catalyst composition comprising a zeolite
catalyst having active internal Bronsted acid sites and
substantially inactive surface acid sites achieved by the presence
of a rare earth or yttrium oxide on the surface.
[0011] A method of making a higher olefin from a lower olefin
containing stream, the method comprising: contacting the olefin
containing stream with a surface-deactivated catalyst composition
comprising a zeolite catalyst having active internal Bronsted acid
sites and substantially inactive surface acid sites achieved by the
presence of a rare earth or yttrium oxide on the surface, thereby
producing a higher olefin stream and a lighter olefin or vent
stream; separating the lighter olefin or vent stream from the
higher olefin stream; and contacting a portion of the separated
lighter or vent stream with the surface-deactivated catalyst
composition. The method further comprising contacting at least a
portion of the higher olefin stream with a catalyst for
hydroformylation.
[0012] These and other features and attributes of the disclosed
compositions and oligomerization processes of the present
disclosure and their advantageous applications and/or uses will be
apparent from the detailed description which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 depicts the performance of Yttria-containing ZSM-22
according to the present disclosure.
DETAILED DESCRIPTION
[0014] A method for the preparation of olefin oligomerization
catalysts comprising a ten-ring zeolite with its surface acid sites
deactivated with yttrium or a rare earth oxide. Catalyst
compositions are disclosed herein. Processes disclosed herein
include processes for the oligomerization of light olefin
containing feeds comprising contacting one or more olefins with the
disclosed catalyst and the subsequent hydroformylation or
hydrogenation of the higher olefin to produce alcohols or saturated
hydrocarbons. All numerical values within the detailed description
and the claims herein are understood as modified by "about."
[0015] In step one of an improved oligomerization catalyst
preparation, a 10-ring zeolite is treated with an yttrium or rare
earth salt solution followed by air calcinations to convert at
least some of the surface acid sites to yttrium or rare earth oxide
bound sites.
[0016] The disclosure describes a method for the preparation of a
yttrium or rare earth surface modified 10-ring zeolite
oligomerization catalyst system. It describes a process where in
step (1) a desired amount of the yttrium or rare earth is reacted
as the yttrium or rare earth salt solution with the 10-ring zeolite
to reduce the surface acidity of the 10-ring zeolite. Incipient
wetness is defined as the condition when just enough liquid has
been added to a porous solid to just fill all the pore. If more
liquid is added to the mixture, it coats the outer surface,
changing the appearance from dull to glistening. On drying,
catalyst materials added in an incipient wetness impregnation will
deposit in the pores rather than on the outer surface (see
"Petroleum Catalysis in Nontechnical Language", by John Magee and
Geoffrey Dolbear; copyright 1998 by Pennwell Publishing Company,
Tulsa, Okla.
[0017] Yttrium oxide and lanthanum oxide are exemplary embodiments
of the specific oxides that are useful in this disclosure.
[0018] In the second step of the preparative method of the
disclosure, the yttria or rare earth bound material formed in step
(1) is air dried at 100.degree. C., calcined in air at 400.degree.
C. to form corresponding oxide, then cooled and available for use
as an oligomerization catalyst.
[0019] One of the advantages of this preparative method is that
there is an optimum amount of yttrium oxide or rare earth oxide
that is reacted with the 10-ring zeolite surface acid sites such
that the most desirable product selectivity and reactivity is
achieved. Thus, one can control the amount of yttrium or rare earth
reagent required. Another advantage of the method disclosed is that
the catalyst compositions of this preparative method are thermally
stable at temperatures at least to about 300.degree. C.,
temperatures well above the end or run temperature for olefin
oligomerization to higher olefin products. Another advantage of the
method disclosed is that the resulting catalyst is useful with both
propylene and butene feed streams to generate higher olefin
products.
[0020] The present disclosure also provides for a process for
producing a higher olefin by oligomerizing a lower olefin, the
process comprising: contacting the lower olefin under
oligomerization conditions with a substantially surface-deactivated
catalyst composition comprising a zeolite catalyst having active
internal Bronsted acid sites and substantially inactive surface
acid sites achieved by the presence of a rare earth or yttrium
oxide on the surface.
[0021] Additionally, the present disclosure includes a method of
making a higher olefin from a lower olefin containing stream, the
method comprising: contacting the olefin containing stream with a
surface-deactivated catalyst composition comprising a zeolite
catalyst having active internal Bronsted acid sites and
substantially inactive surface acid sites achieved by the presence
of a rare earth or yttrium oxide on the surface, thereby producing
a higher olefin stream and a lighter olefin or vent stream;
separating the lighter olefin or vent stream from the higher olefin
stream; and contacting a portion of the separated lighter or vent
stream with the surface-deactivated catalyst composition. The
method further comprising contacting at least a portion of the
higher olefin stream with a catalyst for hydroformylation.
[0022] The method of making a substantially surface-deactivated
catalyst composition optionally includes: contacting a zeolite
catalyst with a rare earth or yttrium salt solution, followed by
air calcination to convert the surface species into the
corresponding oxide, and therefore rendering the surface of the
zeolite catalyst substantially inactive for acidic reaction. Rare
earth or yttrium oxides are solids and cannot be introduced as
such. Accordingly, they are introduced as soluble salt solutions
(incipient wetness method), then converted to oxides.
[0023] This catalyst composition is useful for the preparation of
olefin derivatives via olefin oligomerization to produce lightly
branched higher olefins. Such lightly branched higher olefins are
formed by the method comprising the steps of: (1) treating a
zeolite (e.g., a 10-ring zeolite) via incipient wetness with a
yttrium or rare earth salt solution, (2) drying the impregnated
zeolite catalyst overnight in air at temperature in the range
between about 100 to 120.degree. C., preferably 100.degree. C., and
(3) beating the impregnated zeolite catalyst in the range between
about 350 to 450.degree. C., preferably 400.degree. C., in air for
four hours so the yttrium or rare earth is converted to the
corresponding oxide, and cooling the catalyst.
[0024] The zeolite is chosen from ZSM-22, ZSM-23, or ZSM-57.
[0025] The rare earth oxide used to modify the zeolite surface acid
sites is chosen from lanthanum oxide or lanthanide oxides.
[0026] Furthermore, the present disclosure includes a method for
the preparation of lightly branched higher olefins (e.g., between
about C.sub.6 to about C.sub.15 range) via olefin oligomerization
comprises contacting a C.sub.3.sup.= to C.sub.5.sup.= light olefin
containing stream using a modified 10-ring zeolite catalyst where
the surface acid sites are at least partly neutralized with yttrium
or rare earth oxides.
[0027] The reaction of the yttrium or rare earth modified 10-ring
zeolite catalyst with the olefin containing stream is conducted at
a temperature in the range between about 150 to about 250.degree.
C. The reaction of the olefin containing stream with the catalyst
is carried at a pressure between about 300 to about 1000 psig and a
feed flow rate between about 0.1 to about 10 WHSV.
[0028] The olefin in the olefin containing stream is chosen from
propylene, butenes including 1- and 2-butene (cis and trans),
isobutylene, or pentenes including 1- and 2-pentene (cis and
trans), 2-methyl-2-butene or 3-methyl-1-butene.
[0029] Sources of the olefin in the olefin containing stream are
from a steam cracker stream or from a C.sub.4.sup.+ fraction
separated from the hydrocarbon product produced by an oxygenate to
olefin reaction unit. C.sub.4 hydrocarbon mixtures are generally
available in any refinery employing steam cracking to produce
olefins; a crude steam cracked butene stream, Raffinate-1 (the
product of remaining after solvent extraction or hydrogenation to
remove butadiene from the crude steam cracked butene stream) and
Raffinate-2 (the product remaining after removal of butadiene and
isobutene from the crude steam cracked butene stream). Generally,
these streams have compositions within the weight ranges indicated
in Table A below.
TABLE-US-00001 TABLE A Crude Raffinate 1 Raffinate 2 C.sub.4
Solvent Hydro- Solvent Hydro- Component stream Extraction genation
Extraction genation Butadiene 30-85% 0-2% 0-2% 0-1% 0-1% C4 0-15%
0-0.5% 0-0.5% 0-0.5% 0-0.5% acetylenes Butene-1 1-30% 20-50% 50-95%
25-75% 75-95% Butene-2 1-15% 10-30% 0-20% 15-40% 0-20% Isobutene
0-30% 0-55% 0-35% 0-5% 0-5% N-butane 0-10% 0-55% 0-10% 0-55% 0-10%
Iso-butane 0-1% 0-1% 0-1% 0-2% 0-2%
[0030] Other refinery mixed C.sub.4 streams, such as those obtained
by catalytic cracking of naphthas and other refinery feedstocks,
typically have the following composition:
TABLE-US-00002 Propylene 0-2 wt % Propane 0-2 wt % Butadiene 0-5 wt
% Butene-1 5-20 wt % Butene-2 10-50 wt % Isobutene 5-25 wt %
Iso-butane 10-45 wt % N-butane 5-25 wt %
[0031] C.sub.4 hydrocarbon fractions obtained from the conversion
of oxygenates, such as methanol, to lower olefins more typically
have the following composition:
TABLE-US-00003 Propylene 0-1 wt % Propane 0-0.5 wt % Butadiene 0-1
wt % Butene-1 10-40 wt % Butene-2 50-85 wt % Isobutene 0-10 wt % N-
+ iso-butane 0-10 wt %
[0032] Any one or any mixture of the above C.sub.4 hydrocarbon
mixtures can be used in the process of the invention. In addition
to linear butenes and butanes, these mixtures typically contain
components, such as isobutene and butadiene, which can be
deleterious to the process of the invention. For example, the
normal alkylation products of isobutene with benzene are
tert-butylbenzene and iso-butylbenzene which, as previously stated,
act as inhibitors to the subsequent oxidation step. Thus, prior to
the alkylation step, these mixtures preferably are subjected to
butadiene removal and isobutene removal. For example, isobutene can
be removed by selective dimerization or reaction with methanol to
produce MTBE, whereas butadiene can be removed by extraction or
selective hydrogenation to butene-1.
[0033] In addition to other hydrocarbon components, commercial
C.sub.4 hydrocarbon mixtures typically contain other impurities
which could be detrimental to the alkylation process. For example,
refinery C.sub.4 hydrocarbon streams typically contain nitrogen and
sulfur impurities, whereas C.sub.4 hydrocarbon streams obtained by
oxygenate conversion process typically contain unreacted oxygenates
and water. Thus, prior to the alkylation step, these mixtures may
also be subjected to one or more of sulfur removal, nitrogen
removal and oxygenate removal, in addition to butadiene removal and
isobutene removal. Removal of sulfur, nitrogen, oxygenate
impurities is conveniently effected by one or a combination of
caustic treatment, water washing, distillation, adsorption using
molecular sieves and/or membrane separation. Water is also
typically removed by adsorption.
[0034] Although not preferred, it is also possible to employ a
mixture of a C.sub.4 alkylating agent, as described above, and
C.sub.3 alkylating agent, such as propylene, as the alkylating
agent in the alkylation step of the invention so that the
alkylation step produces a mixture of cumene and sec-butylbenzene.
The resultant mixture can then be processed through oxidation and
cleavage, to make a mixture of acetone and MEK, along with phenol,
preferably where the molar ratio of acetone to phenol is 0.5:1, to
match the demand of bisphenol-A production.
[0035] A still further method of making higher olefins from light
olefin containing stream includes contacting the light olefin
containing stream with an oligomerization catalyst comprising a
yttrium or rare earth modified 10-ring zeolite catalyst composition
to produce a product containing higher olefin and a vent stream;
separating the vent stream from the higher olefin; and contacting a
portion of the separated vent stream with the oligomerization
catalyst.
[0036] In another embodiment the present disclosure relates to a
higher olefin product derived from a C.sub.4.sup.+ feed stream, the
product characterized by having a low extent of branching.
[0037] A higher olefin C.sub.8 and C.sub.12 product composition
having a product branching defined as: Branching=0.times.%
linear+1.times.% mono-branched+2.times.% di-branched+3.times.%
tri-branched, where: % linear+% mono-branched+% di-branched+%
tri-branched=100%.
[0038] A higher olefin C.sub.16 product composition having a
product branching defined as: Branching=0.times.% linear+1.times.%
mono-branched+2.5.times.% (di- and tri-branched) where: % linear+%
mono-branched+% (di- and tri-branched)=100%.
[0039] In another embodiment the present disclosure relates to a
higher olefin product derived from a propylene containing feed
stream, the product characterized by having a low extent of
branching.
[0040] A higher olefin C.sub.6 product composition having a product
branching defined as: Branching=0.times.%
linear+1.times.mono-branched+2.times.% di-branched, where: %
linear+% mono-branched+% di-branched=100%.
[0041] A higher olefin C.sub.9 and C.sub.12 product composition
having a product branching defined as: Branching=0.times.%
linear+1.times.% mono-branched+2.times.% di-branched+3.times.%
tri-branched, where: % linear+% mono-branched+% di-branched+%
tri-branched=100%.
[0042] In another embodiment of the disclosure, the olefin
derivatives from the catalytic olefin oligomerization process are
further converted via hydroformylation and hydrogenation to
branched alcohols. The branched alcohols are usefully esterified
with, for example, phthalic anhydride, adipic acid, or trimellitic
anhydride to generate esters useful as plasticizers.
[0043] In another embodiment of the disclosure, the higher olefin
products from the catalytic olefin oligomerization process are
further converted via hydrogenation to branched saturated
hydrocarbons. The branched saturated hydrocarbons are usefully
applied as functional fluids. Furthermore, these higher olefins can
be further converted via alkylation with benzene or phenol to make
sulfonate detergent precursors.
[0044] The following examples illustrate the present disclosure and
the advantages thereto without limiting the scope thereof.
EXAMPLES
Experimental Details
[0045] Below are examples of the preparation of comparative
catalysts using collidine as the surface modifying agent
(Comparative Example 1) and of the catalyst systems of this
disclosure. Other species within the range of the detailed
description of the disclosure may work.
Comparative Example 1
Preparation of Collidine/ZSM-22
[0046] The ZSM-22 catalyst is a 1/8'' trilobe extrudate with 75%
zeolite and 25% alumina binder. This zeolite crystal has a
SiO.sub.2/Al.sub.2O.sub.3 molar ratio of 65. This is the base case
catalyst used for surface modification. See U.S. Pat. Nos.
4,481,177, 4,556,477, and 4902406 assigned to Mobil Chemical
Company, which are incorporated herein in their entirety by
reference thereto.
[0047] 8.5 g of ZSM-22 as 1/8'' trilobe extrudates as defined above
was used for collidine treatment. 20 cc of pentane were added to a
round-bottom flask containing the catalyst. 10 cc of pentane were
added to a jar containing 0.077 g of collidine
(2,4,6-Trimethylpyridine, 99% purity from Aldrich, CAS# 108-75-8).
The collidine solution was added to the flask. The final mixture
was allowed to stand at room temperature for two hours with
occasional shaking. Pentane was removed by purging the flask with
nitrogen. The catalyst was dried to a constant weight at room
temperature under vacuum. The resulting catalyst had a collidine/Al
(zeolitic Al) molar ratio of 0.2.
Example 2
Preparation of Yttria/ZSM-22
[0048] The same base case ZSM-22 catalyst as described in
Comparative Example 1 was used for preparation of a
yttria-containing catalyst. 0.287 g of yttrium nitrate hexahydrate
(Y(NO.sub.3).sub.3.6H.sub.2O from Aldrich, CAS # 13494-98-9) was
dissolved in water to make a solution with a volume of 7 cc and
this solution was impregnated by incipient wetness onto 10 grams of
1/8'' trilobe extrudates of alumina-bound ZSM-22. The sample was
dried in air at 100.degree. C. overnight and heated in air at
0.5.degree. C./min to 400.degree. C., held at that temperature for
4 hours, and then cooled to room temperature. The finished
catalyst, designated as 24151-163 below, contains 0.84 wt % of
yttria and has a Y/Al (zeolitic Al) molar ratio of 0.2. The amounts
of materials used for this preparation are shown in Table 1.
[0049] Additional catalyst samples containing different levels of
yttria on ZSM-22 were prepared using the same procedure described
above by adjusting the amount of yttrium nitrate impregnated onto
the extrudates. Wettability was maintained at 0.70 cc solution per
gram of catalyst. Drying and calcination conditions were the same
as with sample 24151-163. The amounts of materials used for
preparation are also shown in Table 1.
TABLE-US-00004 TABLE 1 Variation of Y2O3 Loading on ZSM-22 Weight
of Weight of Wt % of Y/Al Yttrium Nitrate, ZSM-22 Y.sub.2O.sub.3
Molar Ratio Sample # g Extrudates, g on ZSM-22 (zeolitic Al)
24151-162 0.143 10 0.42 0.1 24151-163 0.287 10 0.84 0.2 24151-173
1.160 20 1.68 0.4 24151-193 1.750 20 2.52 0.6
Example 3
Preparation of Lanthanum Oxide/ZSM-22
[0050] Samples similar to those described in Example 2 were
prepared but with lanthanum oxide rather than yttrium oxide
impregnated onto ZSM-22 extrudates. The two compositions shown in
Table 2 were prepared in an analogous way to those shown in Example
2 using lanthanum nitrate hexahydrate (La(NO.sub.3).sub.3.6H.sub.2O
from Aldrich, CAS # 10277-43-77) as the lanthanum source and with
wettabilities at 0.70 cc/g catalyst. Drying and calcination
conditions were the same as shown in Example 2.
TABLE-US-00005 TABLE 2 Lanthanum Oxide on ZSM-22 Weight of Y/Al
Weight of ZSM-22 Ratio Lanthanum Extrudates, (Zeolitic Sample
Sample # Nitrate, g g Al) 1.22 wt % La.sub.2O.sub.3 24151-173-A
0.65 20 0.2 2.44 wt % La.sub.2O.sub.3 24151-193-A 1.33 20 0.4
[0051] Below are examples of the oligomerization process using the
catalysts prepared in Comparative Example 1, Example 2, and Example
3 above. Other species within the range of the detailed description
of the disclosure may work.
Example 4
2-Butene Oligomerization with Untreated ZSM-22
[0052] Two grams of base case ZSM-22, as 1/8'' trilobe extrudate
with 25% alumina binder, was used for oligomerization. The catalyst
was diluted with sand to 18 cc and charged to an isothermal,
down-flow, 0.5'' inch (inside diameter) fixed-bed reactor. The
catalyst was dried at 150.degree. C. and atmospheric pressure with
100 cc/min flowing N.sub.2 for 2 hours. N.sub.2 was turned off and
the reactor pressure was set to 750 psig by a grove loader. The
2-butene feed (57.1% cis-butene, 37.8% trans-butene, 2.5% n-butane,
0.8% isobutene and 1-butene, 1.8% others) was introduced into the
reactor at 60 cc/hr for 2 hour, then reduced to 1.7 WHSV while the
reactor pressure was increased to 750 psig. After reaching 750
psig, the reactor temperature was ramped at 2.degree. C./min to
200.degree. C. After line out for 12 hours at 200.degree. C., 750
psig, and 1.7 WHSV on 2-butene feed, liquid products were collected
in a cold trap. Additional samples were collected at 2.2 WHSV on
2-butene feed. Representative data are shown in Table 3.
[0053] Product carbon number distribution was determined with an
HP-5890 GC equipped with a 60 meter DB-1 column (0.25 mm id and 1
.mu.m film thickness). Product branching was determined with an
H.sub.2-GC. This was an HP-5890 GC equipped with (a) a 100 meter
DB-1 column (0.25 mm id and 0.5 .mu.m film thickness); (b) hydrogen
as the carrier gas; and (c) 0.1 g of 0.5% Pt/alumina catalyst in
the GC insert for in-situ hydrogenation. Both GC used the same
temperature program: 2 min at -20.degree. C., 8.degree. C./min to
275.degree. C., hold at 275.degree. C. for 35 min. Branching values
were determined by the following formulas:
[0054] For C.sub.8 and C.sub.12 olefins:
Branching=0.times.% linear+1.times.%
mono-branched+2.times.di-branched+3.times.% tri-branched [0055]
Where: % linear+% mono-branched+% di-branched+%
tri-branched=100%
[0056] For C.sub.16 olefins:
Branching=0.times.% linear+1.times.% mono-branched+2.5.times.% (di-
and tri-branched) [0057] Where: % linear+% mono-branched+% (di- and
tri-branched)=100%
[0058] An average branching index of 2.5 was used for di- and
tri-branched C.sub.16 species since these components overlapped on
our H.sub.2-GC. Representative data are tabulated below.
Comparative Example 5
2-Butene Oligomerization with Collidine/ZSM-22
[0059] Eight grams of collidine-treated ZSM-22, as prepared in
Comparative Example 1, was used for oligomerization. The catalyst
was diluted with sand to 18 cc and charged to an isothermal,
down-flow, 0.5 inch (inside diameter) fixed-bed reactor. The
catalyst was dried at 150.degree. C. and atmospheric pressure with
100 cc/min flowing N.sub.2 for 2 hours. N.sub.2 was turned off and
reactor pressure was set to 750 prig by a grove loader. The
2-butene feed (57.1% cis-butene, 37.8% trans-butene, 2.5% n-butane,
0.8% isobutene and 1-butene, 1.8% others) was introduced into the
reactor at 60 cc/hr for 2 hours, then reduced to 0.18 WHSV (2.3
cc/hr) while the reactor pressure was increased to 750 psig, After
reaching 750 psig, the reactor temperature was ramped at 2.degree.
C./min to 200.degree. C. After line out for 12 hours at 200.degree.
C., 750 psig, and 0.18 WHSV on 2-butene feed, liquid products were
collected in a cold trap. Representative data are shown in Table
3.
[0060] Data in Table 3 show that collidine-treated ZSM-22 is
effective for reducing branching of olefin products while
maintaining octene selectivity. The loss of catalyst activity after
surface treatment, as reflected by the reduced feed flow rate to
achieve constant conversion, indicates that surface acid sites were
titrated by collidine.
[0061] However, when the catalyst was tested at elevated
temperatures (up to 260.degree. C.), a loss of collidine was
observed. The loss was evident at 260.degree. C., which resulted in
an increase in catalyst activity and product branching.
Representative data are shown in Table 4b.
TABLE-US-00006 TABLE 3 2-Butene Oligomerization with ZSM-22 and
Collidine-Treated ZSM-22 ZSM-22 ZSM-22 Catalyst Untreated with
Collidine Base/Al Molar Ratio -- 0.2 collidine/Al Sample
Identification 508A096005 508A087005 Temperature, .degree. C. 199
200 Pressure, psig 760 747 Feed Flow Rate, WHSV 2.2 0.25 Days on
Stream 6.7 4.8 Conversion % 57.6 54.7 Selectivity, wt % C4- 0.00
0.00 C5-7 0.48 0.54 C8 = 75.74 76.80 C9-11 0.22 0.21 C12 = 15.40
20.27 C16 = 5.84 1.84 C20 = 1.91 0.27 C24+ 0.40 0.08 Sum 100.0
100.0 Product Branching Me/C8 1.41 0.97 Me/C12 2.05 1.13 Me/C16
2.28 1.77
Example 6
2-Butene Oligomerization with Yttria/ZSM-22
[0062] Eight grams of ZSM-22, containing 1.68 wt % of yttria
(Sample # 24151-173) as prepared in Example 2, was used for
oligomerization. The same procedure described in Example 5 was used
to start up the run. The catalyst was tested under a variety of
process conditions as shown in FIG. 1 (arrows indicate sequence of
conditions for data collection). After testing at 250.degree. C.
and 300.degree. C., the catalyst performance was re-evaluated at
startup conditions (200.degree. C., 0.18-0.2 WHSV or SV),
respectively (FIG. 1).
[0063] Representative data are compared with that of untreated
ZSM-22 in Table 4a. The data show that yttria-containing ZSM-22 is
effective for reducing branching of olefin products while
maintaining octene selectivity. The loss of catalyst activity after
surface treatment, as reflected by the reduced feed flow rate to
achieve constant conversion, indicates that at least some of the
surface acid sites were titrated by yttria. The data also show that
yttria-containing ZSM-22 can be operated at 200-300.degree. C. to
produce higher olefins with reduced branching.
TABLE-US-00007 TABLE 4a 2-Butene Oligomerization with ZSM-22 and
Yttria-Treated ZSM-22 Catalyst ZSM-22 ZSM-22 ZSM-22 untreated with
collidine with 1.68 wt % Y.sub.2O.sub.3 Base/Al Molar Ratio -- 0.2
collidine/Al 0.4 Y/Al 0.4 Y/Al 0.4 Y/Al Run Identification
508A096005 508A087014 508B091005 508B091011 508B091019 Temperature,
.degree. C. 199 200 200 250 300 Pressure, psig 760 738 747 759 753
Feed Flow Rate, WHSV 2.2 0.18 0.18 1.4 10.0 Days on Stream 6.7 15.8
4.8 16.3 23.9 Conversion % 57.6 65.2 66.3 86.7 72.3 Selectivity, wt
% C4- 0.00 0.01 1.27 4.96 3.59 C5-7 0.48 0.61 0.54 1.11 2.57 C8 =
75.74 71.76 69.50 63.60 66.27 C9-11 0.22 0.23 0.21 0.71 1.39 C12 =
15.40 23.44 16.97 19.39 19.31 C16 = 5.84 2.93 8.23 7.88 5.73 C20 =
1.91 0.94 3.22 2.30 1.10 C24+ 0.40 0.08 0.06 0.04 0.00 Sum 100.0
100.00 100.0 100.0 100.0 Product Branching Me/C8 1.41 1.02 1.14
1.24 1.24 Me/C12 2.05 1.22 1.76 1.79 1.87 Me/C16 2.28 1.89 2.25
2.08 2.07
[0064] Representative data of yttria/ZSM-22 are also compared with
that of collidine/ZSM-22 in Table 4b. After a high temperature data
collection (260.degree. C. with collidine/ZSM-22 and 300.degree. C.
with yttria/ZSM-22), C.sub.8 branching (Me/C8) for both catalysts
experienced an increase. However, the branching increase for
yttria/ZSM-22 catalyst with a delta temperature of 100.degree. C.
is comparable with that of collidine/ZSM-22 with a delta
temperature of 60.degree. C., indicating the more stable nature of
yttria/ZSM-22 to elevated temperatures.
TABLE-US-00008 TABLE 4b 2-Butene Oligomerization with
Collidine/ZSM-22 and Yttria/ZSM-22 Catalyst Collidine/ZSM-22 1.68
wt % Y.sub.2O.sub.3/ZSM-22 Base/Al Molar Ratio 0.2 Collidine/Al 0.4
Y/Al Run Identification 508A087014 508A087022 508A087024 508B091005
508B091019 508B091023 Temperature, .degree. C. 200 260 200 200 300
200 Pressure, psig 738 755 746 747 753 751 Feed Flow Rate, WHSV
0.18 3.1 0.19 0.18 10.0 0.19 Days on Stream 15.8 20.2 23.8 4.8 23.9
26.8 Conversion % 65.2 78.3 86.1 66.3 72.3 91.4 Selectivity, wt %
C4- 0.01 1.21 0.00 1.27 3.59 2.81 C5-7 0.61 1.39 0.60 0.54 2.57
0.64 C8 = 71.76 63.68 59.68 69.50 66.27 52.04 C9-11 0.23 0.85 0.30
0.21 1.39 0.48 C12 = 23.44 25.46 30.79 16.97 19.31 26.40 C16 = 2.93
5.28 5.89 8.23 5.73 12.82 C20 = 0.94 1.60 2.34 3.22 1.10 4.70 C24+
0.08 0.52 0.41 0.06 0.00 0.10 Sum 100.0 100.0 100.0 100.0 100.0
100.0 Product Branching Me/C8 1.02 1.15 1.19 1.14 1.24 1.29 Me/C12
1.22 1.48 1.43 1.76 1.87 1.96 Me/C16 1.89 1.97 2.05 2.25 2.07
2.15
[0065] Catalysts with 0.42, 0.84 and 2.52 wt % yttria, as prepared
in Example 2, were also tested for 2-butene oligomerization. It was
found that the 0.42% and 0.84% yttria samples did not have
sufficient levels of yttria on catalysts surface to reduce product
branching. The 2.52% yttria sample, on the other hand, had a little
too much yttria on the catalyst. The excess yttria did not perform
as well as the 1.68 wt % yttria sample.
Example 7
2-Butene Oligomerization with Lanthanum Oxide/ZSM-22
[0066] Eight grams of ZSM-22, containing 2.44 wt % of
La.sub.2O.sub.3 as prepared in Example 3, was used for
oligomerization. The same procedure described in Example 5 was used
to start up the run. The catalyst was tested at 200.degree. C.
Representative data are compared with that of ZSM-22,
collidine-treated ZSM-22, yttria-treated ZSM-22 in Table 5. The
data show that La.sub.2O.sub.3-containing ZSM-22 is effective for
reducing branching of olefin products while maintaining octene
selectivity. The loss of catalyst activity after surface treatment,
as reflected by the reduced feed flow rate to achieve constant
conversion, indicates that at least some of the surface acid sites
were titrated by La.sub.2O.sub.3.
TABLE-US-00009 TABLE 5 Comparison of Catalyst Performance for
2-Butene Oligomerization ZSM-22 ZSM-22 ZSM-22 ZSM-22 Catalyst
Untreated with collidine with 1.68% Y.sub.2O.sub.3 with 2.44%
La.sub.2O.sub.3 Base/Al Molar Ratio -- 0.2 0.4 Y/Al 0.4 La/Al
collidine/Al Run Identification 508A096005 508A087014 508A091004
508A098011 Temperature, .degree. C. 199 200 200 200 Pressure, psig
760 738 725 776 Feed Flow Rate, WHSV 2.2 0.18 0.17 0.18 Days on
Stream 6.7 15.8 3.8 20.8 Conversion % 57.6 65.2 66.3 55.01
Selectivity, wt % C4- 0.00 0.01 0.84 0.00 C5-7 0.48 0.61 0.70 0.56
C8 = 75.74 71.76 72.10 75.57 C9-11 0.22 0.23 0.27 0.48 C12 = 15.40
23.44 16.74 16.18 C16 = 5.84 2.93 7.47 6.22 C20 = 1.91 0.94 1.85
0.99 C24+ 0.40 0.08 0.03 0.00 Sum 100.0 100.0 100.0 100.0 Product
Branching Me/C8 1.41 1.02 1.15 1.16 Me/C12 2.05 1.22 1.74 1.72
Me/C16 2.28 1.89 2.21 2.11
Example 8
Propylene Oligomerization with ZSM-22
[0067] 0.5 gram of base case ZSM-22 was used for propylene
oligomerization. A similar startup procedure described in Example 5
was used to start the run using propylene feed (99% purity) as
feed. The catalyst was tested at 200.degree. C. Representative data
are shown in Table 6. Branching values were determined by the
following formulas.
[0068] For C.sub.6 olefins:
Branching=0.times.% linear+1.times.% mono-branched+2.times.%
di-branched [0069] Where: % linear+% mono-branched+%
di-branched=100%
[0070] For C.sub.9 and C.sub.12 olefins:
Branching=0.times.% linear+1.times.% mono-branched+2.times.%
di-branched+3.times.% tri-branched [0071] Where: % linear+%
mono-branched+% di-branched+% tri-branched=100%
Example 9
Propylene Oligomerization with Yttria/ZSM-22
[0072] 1.4 grams of ZSM-22, containing 0.84 wt % of Y.sub.2O.sub.3
as prepared in Example 2, were used for propylene oligomerization.
A similar startup procedure described in Example 5 was used to
start the run using propylene (99% purity) as feed. The catalyst
was tested at 200.degree. C. Representative data are shown in Table
6.
[0073] Tests were also conducted using ZSM-22 modified with three
different levels of yttria, as prepared in Example 2 (0.42 wt %
Y.sub.2O.sub.3, sample 24151-162; 1.68 wt % Y.sub.2O.sub.3, sample
24151-173; and 2.52 wt % Y.sub.2O.sub.3, sample 24151-193). The
catalyst was tested at 200.degree. C. Representative data are shown
in Table 6.
Example 10
Propylene Oligomerization with Lanthanum Oxide/ZSM-22
[0074] Tests were also conducted using ZSM-22 modified with two
different levels of lanthanum oxide, as prepared in Example 3. A
similar startup procedure described in Example 5 was used to start
the run using propylene (99% purity) as feed. The 1.22 wt %
La.sub.2O.sub.3 sample was tested at 200.degree. C. The 2.44 wt %
La.sub.2O.sub.3 sample was tested at 230.degree. C. due to its
reduced activity. Representative data are also shown in Table
6.
[0075] The results in Table 6 show that ZSM-22 catalysts modified
with yttria or lanthanum oxide are effective for reducing branching
of the C.sub.9 and C.sub.12 higher olefin products. The loss of
catalyst activity after surface treatment, as reflected by the
reduced feed flow rate to achieve similar conversion, indicates
that at least some of the surface acid sites were titrated by
yttria or lanthanum oxide.
TABLE-US-00010 TABLE 6 Comparison of Propylene Oligomerization Data
0.42 wt % 0.84 wt % 1.68 wt % 2.52 wt % 1.22 wt % 2.44 wt % ZSM-22
Catalyst Untreated Y.sub.2O.sub.3 Y.sub.2O.sub.3 Y.sub.2O.sub.3
Y.sub.2O.sub.3 La.sub.2O.sub.3 La.sub.2O.sub.3 Y/Al or La/Al Molar
0.1 0.2 0.4 0.6 0.2 0.4 Ratio Sample # -- 24151- 24151-163 24151-
24151- 24151-173-A 24151-193-A 162 173 193 Run Identification
512A011-13 512A027-2 512A022-3 512A024-2 512A026-1 512A025-5
512A033-10 Temperature, .degree. C. 200 201 200 200 201 200 230
Pressure, psig 760 751 754 748 752 756 753 Feed Flow Rate, 8.0 2.8
1.6 1.6 1.7 1.6 13 WHSV Days on Stream 7.9 1.8 2.8 1.8 0.8 4.8 6.8
Conversion % 91.3 82.34 87.2 88.4 71.3 81.8 92.93 Selectivity, wt %
C3 0.19 0.00 0.00 0.00 0.00 0.00 0.00 C4 = s 0.04 0.05 0.04 0.05
0.03 0.05 0.10 C4 0.02 0.01 0.04 0.02 0.02 0.04 0.02 C5s 1.88 0.16
0.23 0.28 0.25 0.19 0.31 C6 46.03 62.99 58.86 51.06 60.50 62.77
56.75 C7-8 0.56 0.32 0.41 0.63 0.50 0.42 0.57 C9 34.19 23.64 24.72
27.12 22.69 22.78 27.09 C10-11 0.57 0.23 0.29 0.62 0.22 0.31 0.47
C12 14.90 10.72 12.71 16.13 12.73 11.34 12.03 C15 1.27 1.47 2.25
2.92 2.53 1.75 2.11 C16+ 0.35 0.41 0.42 1.16 0.52 0.32 0.55 Sum
100.0 100.0 100.0 100.0 100.0 100.0 100.0 Product Branching Me/C6
0.93 0.92 0.92 0.92 0.91 0.92 0.90 Me/C9 1.85 1.63 1.58 1.61 1.62
1.56 1.49 Me/C12 2.42 2.32 2.30 2.32 2.32 2.30 2.17
[0076] The examples above show that rare earth and yttrium oxides
can be used to modify surface acid sites of 10-ring zeolites such
as ZSM-22. When used for olefin oligomerization, the modified
catalysts are effective for reducing product branching. Most
importantly, the modified catalyst can be used at 200-300.degree.
C. to produce higher olefins. Therefore, these catalysts should
survive commercial end of cycle temperature of about 250.degree. C.
Unlike collidine which decomposes during air regeneration, rare
earth and yttrium oxides are stable and should survive oxidative
catalyst regeneration.
[0077] Applicants have attempted to disclose all embodiments and
applications of the disclosed subject matter that could be
reasonably foreseen. However, there may be unforeseeable,
insubstantial modifications that remain as equivalents. While the
present disclosure has been described in conjunction with specific,
exemplary embodiments thereof, it is evident that many
alternations, modifications, and variations will be apparent to
those skilled in the art in light of the foregoing description
without departing from the spirit or scope of the present
disclosure. Accordingly, the present disclosure is intended to
embrace all such alterations, modifications, and variations of the
above detailed description. All patents and other documents cited
herein, including priority documents, are fully incorporated by
reference to the extent such disclosure is not inconsistent with
this disclosure and for all jurisdictions in which such
incorporation is permitted. When numerical lower limits and
numerical upper limits are listed herein, ranges from any lower
limit to any upper limit are contemplated.
* * * * *