U.S. patent application number 11/987871 was filed with the patent office on 2008-05-08 for composite oxide catalyst and method of producing the same.
Invention is credited to Tomoatsu Iwakura, Nariyasu Kanuka, Isao Teshigahara.
Application Number | 20080107583 11/987871 |
Document ID | / |
Family ID | 27577808 |
Filed Date | 2008-05-08 |
United States Patent
Application |
20080107583 |
Kind Code |
A1 |
Teshigahara; Isao ; et
al. |
May 8, 2008 |
Composite oxide catalyst and method of producing the same
Abstract
A composite oxide catalyst for the oxidation of an olefin
containing Mo and Bi as essential components, characterized in that
it has a specific surface area of 5 to 25 m.sup.2/g and a pore
volume of 0.2 to 0.7 cc/g, and has a pore diameter distribution
wherein the volume of the pores having a pore diameter of 0.03 to
0.1 .mu.m accounts for 30% or more of the total pore volume, the
volume of the pores having a pore diameter of 0.1 to 1 .mu.m
accounts for 20% or more of the total pore volume, and the volume
of the pores having a pore diameter of less than 0.03 .mu.m is 10%
or less of the total pore volume; a composite oxide catalyst for
use in the vapor phase catalytic oxidation of acrolein or
methacrolein or the like which comprises Mo, Bi and a halogen;
either of the above two composite oxide catalysts which comprises
Mo, Bi, Fe, Si and an element selected from alkali metals and
thallium, and optionally Co, Ni, Mg, Ca, Zn, Ce, Sm, a halogen, B,
P, As and W; a method for preparing any of the above composite
catalysts; and a method for using any of the above composite oxide
catalysts.
Inventors: |
Teshigahara; Isao; (Mie,
JP) ; Kanuka; Nariyasu; (Mie, JP) ; Iwakura;
Tomoatsu; (Mie, JP) |
Correspondence
Address: |
WENDEROTH, LIND & PONACK, L.L.P.
2033 K STREET N. W.
SUITE 800
WASHINGTON
DC
20006-1021
US
|
Family ID: |
27577808 |
Appl. No.: |
11/987871 |
Filed: |
December 5, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10495071 |
Sep 29, 2004 |
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PCT/JP02/11703 |
Nov 8, 2002 |
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11987871 |
Dec 5, 2007 |
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Current U.S.
Class: |
423/263 ;
423/277; 423/306; 423/326; 423/332; 423/463; 423/594.7 |
Current CPC
Class: |
B01J 23/8876 20130101;
B01J 35/1042 20130101; C07C 45/37 20130101; B01J 35/1009 20130101;
B01J 21/08 20130101; B01J 29/048 20130101; C07C 45/35 20130101;
B01J 37/0009 20130101; B01J 35/1014 20130101; B01J 35/108 20130101;
B01J 35/1038 20130101; C07C 45/34 20130101; B01J 23/31 20130101;
B01J 2523/00 20130101; B01J 37/03 20130101; B01J 23/002 20130101;
C07C 51/252 20130101; C07C 45/37 20130101; C07C 47/22 20130101;
C07C 51/252 20130101; C07C 57/04 20130101; B01J 2523/00 20130101;
B01J 2523/12 20130101; B01J 2523/13 20130101; B01J 2523/305
20130101; B01J 2523/3737 20130101; B01J 2523/41 20130101; B01J
2523/54 20130101; B01J 2523/68 20130101; B01J 2523/842 20130101;
B01J 2523/845 20130101; B01J 2523/847 20130101; B01J 2523/00
20130101; B01J 2523/12 20130101; B01J 2523/13 20130101; B01J
2523/22 20130101; B01J 2523/305 20130101; B01J 2523/41 20130101;
B01J 2523/54 20130101; B01J 2523/68 20130101; B01J 2523/842
20130101; B01J 2523/845 20130101; B01J 2523/847 20130101; B01J
2523/00 20130101; B01J 2523/12 20130101; B01J 2523/13 20130101;
B01J 2523/305 20130101; B01J 2523/54 20130101; B01J 2523/68
20130101; B01J 2523/842 20130101; B01J 2523/845 20130101; B01J
2523/847 20130101; B01J 2523/00 20130101; B01J 2523/12 20130101;
B01J 2523/13 20130101; B01J 2523/305 20130101; B01J 2523/41
20130101; B01J 2523/54 20130101; B01J 2523/68 20130101; B01J
2523/842 20130101; B01J 2523/845 20130101; B01J 2523/847 20130101;
B01J 2523/00 20130101; B01J 2523/12 20130101; B01J 2523/13
20130101; B01J 2523/27 20130101; B01J 2523/305 20130101; B01J
2523/41 20130101; B01J 2523/54 20130101; B01J 2523/68 20130101;
B01J 2523/842 20130101; B01J 2523/845 20130101; B01J 2523/847
20130101; B01J 2523/00 20130101; B01J 2523/12 20130101; B01J
2523/13 20130101; B01J 2523/305 20130101; B01J 2523/3712 20130101;
B01J 2523/41 20130101; B01J 2523/54 20130101; B01J 2523/68
20130101; B01J 2523/842 20130101; B01J 2523/845 20130101; B01J
2523/847 20130101; B01J 2523/00 20130101; B01J 2523/12 20130101;
B01J 2523/13 20130101; B01J 2523/41 20130101; B01J 2523/54
20130101; B01J 2523/68 20130101; B01J 2523/842 20130101; B01J
2523/845 20130101; B01J 2523/00 20130101; B01J 2523/12 20130101;
B01J 2523/13 20130101; B01J 2523/3712 20130101; B01J 2523/41
20130101; B01J 2523/54 20130101; B01J 2523/68 20130101; B01J
2523/842 20130101; B01J 2523/00 20130101; B01J 2523/12 20130101;
B01J 2523/13 20130101; B01J 2523/22 20130101; B01J 2523/41
20130101; B01J 2523/54 20130101; B01J 2523/68 20130101; B01J
2523/842 20130101; B01J 2523/845 20130101; B01J 2523/847 20130101;
B01J 2523/00 20130101; B01J 2523/12 20130101; B01J 2523/13
20130101; B01J 2523/27 20130101; B01J 2523/41 20130101; B01J
2523/54 20130101; B01J 2523/68 20130101; B01J 2523/842 20130101;
B01J 2523/845 20130101; B01J 2523/847 20130101; B01J 2523/00
20130101; B01J 2523/12 20130101; B01J 2523/13 20130101; B01J
2523/22 20130101; B01J 2523/23 20130101; B01J 2523/41 20130101;
B01J 2523/54 20130101; B01J 2523/68 20130101; B01J 2523/842
20130101; B01J 2523/845 20130101; B01J 2523/847 20130101; B01J
2523/00 20130101; B01J 2523/12 20130101; B01J 2523/13 20130101;
B01J 2523/30 20130101; B01J 2523/3737 20130101; B01J 2523/41
20130101; B01J 2523/54 20130101; B01J 2523/68 20130101; B01J
2523/845 20130101; B01J 2523/00 20130101; B01J 2523/12 20130101;
B01J 2523/13 20130101; B01J 2523/41 20130101; B01J 2523/54
20130101; B01J 2523/68 20130101; B01J 2523/842 20130101; B01J
2523/845 20130101; B01J 2523/847 20130101; B01J 2523/00 20130101;
B01J 2523/12 20130101; B01J 2523/13 20130101; B01J 2523/37
20130101; B01J 2523/41 20130101; B01J 2523/54 20130101; B01J
2523/68 20130101; B01J 2523/842 20130101; B01J 2523/845 20130101;
B01J 2523/847 20130101; B01J 2523/00 20130101; B01J 2523/12
20130101; B01J 2523/13 20130101; B01J 2523/3712 20130101; B01J
2523/41 20130101; B01J 2523/54 20130101; B01J 2523/68 20130101;
B01J 2523/842 20130101; B01J 2523/845 20130101; B01J 2523/847
20130101 |
Class at
Publication: |
423/263 ;
423/463; 423/306; 423/326; 423/332; 423/594.7; 423/277 |
International
Class: |
C01B 13/00 20060101
C01B013/00; C01F 17/00 20060101 C01F017/00; C01B 33/113 20060101
C01B033/113; C01B 33/32 20060101 C01B033/32; C01B 7/00 20060101
C01B007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 8, 2001 |
JP |
2001-343440 |
Nov 9, 2001 |
JP |
2001-344428 |
Nov 14, 2001 |
JP |
2001-349145 |
Nov 21, 2001 |
JP |
2001-356555 |
Nov 21, 2001 |
JP |
2001-356573 |
Nov 29, 2001 |
JP |
2001-364253 |
Dec 4, 2001 |
JP |
2001-369808 |
Dec 5, 2001 |
JP |
2001-371232 |
Dec 6, 2001 |
JP |
2001-372383 |
Claims
1. A composite oxide catalyst used for oxidation of olefin and
containing molybdenum and bismuth, characterized in that its
specific surface area is in the range of 5-25 m.sup.2/g, and its
pore volume is in the range of 0.2-0.7 cc/g, and that the pore
diameter distribution is such that the volume of pores whose
diameters are 0.03-0.1 .mu.m is 30% or over of the total pore
volume, the volume of pores whose diameters are 0.1-1 .mu.m is 20%
or over of the total pore volume, and the volume of pores whose
diameters are less than 0.03 .mu.m is 10% or less.
2. A composite oxide catalyst used for any of a vapor phase
catalytic oxidation reaction for producing acrolein or methacrolein
from propylene, isobutene or tertiary butanol, a vapor phase
catalytic ammo-oxidation reaction for producing acrylonitrile or
methacrylonitrile from propylene or isobutene, and a vapor phase
catalytic oxidative dehydrogenation reaction for producing
butadiene from butene, and containing Mo, Bi and a halogen as
component elements.
3. A composite oxide catalyst as claimed in claim 1 expressed by
the following general formula (I):
Mo.sub.aBi.sub.bCo.sub.cNi.sub.dFe.sub.eX.sub.fY.sub.gZ.sub.hSi.sub.iO.su-
b.j (1) (wherein X is at least one kind of element selected from
the group consisting of magnesium (Mg), calcium (Ca), zinc (Zn),
cerium (Ce), samarium (Sm) and halogen, Y is at least one of
element selected from the group consisting of sodium (Na),
potassium (K), rubidium (Rb), cesium (Cs) and thallium (Tl), Z is
at least one kind of element selected from the group consisting of
boron (B), phosphorus (P), arsenic (As) and tungsten (W), the
letters a to j are atomic ratios of the respective elements, where
if a=12, then b=0.5-7, c=0-10, d=0-10 (where c+d=1-10), e=0.05-3,
f=0-2, g=0.04-2, h=0-3 and i=5-48, and j is a numeral which
satisfies the oxidation state of the other elements.)
4. A composite oxide catalyst as claimed in claim 1 which is used
in producing acrolein and/or acrylic acid by vapor phase catalytic
oxidation of propylene.
5. A composite oxide catalyst as claimed in claim 1 wherein said
halogen is Cl.
6. A composite oxide catalyst as claimed in claim 1 wherein the
content of said halogen is 0.0005-0.5 atomic weight with respect to
12 atomic weight of Mo.
7-28. (canceled)
29. A composite oxide catalyst as claimed in claim 2 expressed by
the following general formula (I):
Mo.sub.aBi.sub.bCo.sub.cNi.sub.dFe.sub.eX.sub.fY.sub.gZ.sub.hSi.sub.iO.su-
b.j (1) (wherein X is at least one kind of element selected from
the group consisting of magnesium (Mg), calcium (Ca), zinc (Zn),
cerium (Ce), samarium (Sm) and halogen, Y is at least one of
element selected from the group consisting of sodium (Na),
potassium (K), rubidium (Rb), cesium (Cs) and thallium (Tl), Z is
at least one kind of element selected from the group consisting of
boron (B), phosphorus (P), arsenic (As) and tungsten (W), the
letters a to j are atomic ratios of the respective elements, where
if a=12, then b=0.5-7, c=0-10, d=0-10 (where c+d=1-10), e=0.05-3,
f=0-2, g=0.04-2, h=0-3 and i=5-48, and j is a numeral which
satisfies the oxidation state of the other elements.)
30. A composite oxide catalyst as claimed in claim 2 which is used
in producing acrolein and/or acrylic acid by vapor phase catalytic
oxidation of propylene.
31. A composite oxide catalyst as claimed in claim 3 which is used
in producing acrolein and/or acrylic acid by vapor phase catalytic
oxidation of propylene.
32. A composite oxide catalyst as claimed in claim 2 wherein said
halogen is Cl.
33. A composite oxide catalyst as claimed in claim 3 wherein said
halogen is Cl.
34. A composite oxide catalyst as claimed in claim 4 wherein said
halogen is Cl.
35. A composite oxide catalyst as claimed in claim 2 wherein the
content of said halogen is 0.0005-0.5 atomic weight with respect to
12 atomic weight of Mo.
36. A composite oxide catalyst as claimed in claim 3 wherein the
content of said halogen is 0.0005-0.5 atomic weight with respect to
12 atomic weight of Mo.
37. A composite oxide catalyst as claimed in claim 4 wherein the
content of said halogen is 0.0005-0.5 atomic weight with respect to
12 atomic weight of Mo.
38. A composite oxide catalyst as claimed in claim 5 wherein the
content of said halogen is 0.0005-0.5 atomic weight with respect to
12 atomic weight of Mo.
Description
TECHNICAL FIELD
[0001] This invention relates to a composite oxide catalyst used
for selective reactions such as a vapor phase catalytic oxidation
reaction for producing acrolein or methacrolein from propylene,
isobutene or tertiary butanol, a vapor phase contact ammoxidation
reaction for producing acrylonitrile or methacrylonitrile from
propylene or isobutene, and a vapor phase catalytic oxidation type
dehydrogenation reaction for producing butadiene from butene, and a
process for producing the same.
PRIOR ART
[0002] In selective reactions such as a vapor phase catalytic
oxidation reaction for producing acrolein or methacrolein from
propylene, isobutene or tertiary butanol, a vapor phase contact
ammoxidation reaction for producing acrylonitrile or
methacrylonitrile from propylene or isobutene, and a vapor phase
catalytic oxidation type dehydrogenation reaction for producing
butadiene from butene, it is well known that Mo--Bi composite oxide
catalysts are useful, and they are industrially used widely.
[0003] The following patent documents disclose compositions of and
methods for producing Mo--Bi composite oxides used in reactions as
described above: JP patent publications 39-3670, 48-1645, 48-4763,
48-17253, 49-3498, 55-41213, 56-14659, 56-23969, 56-52013,
57-26245, 48-503, 48-514, 48-52713, 48-54027, 48-57916, 55-20610,
55-47144, 55-84541, 59-76541 and 60-122041.
[0004] Among them, except that JP patent publications 55-47144 and
59-76541 disclose producing Mo--Bi or W--Bi beforehand in producing
composite oxide catalysts, any of the others uses bismuth nitrate
as its raw material in Examples, and in the respective
descriptions, water-soluble bismuth compounds, namely bismuth
nitrate or hydroxides are recommended as Bi raw materials. While
the catalysts described therein are considered to be reasonable
formulas in view of uniform dispersion of Bi in composite oxide
catalysts, no sufficient catalytic performance has been
obtained.
[0005] Further, any of the catalysts described therein contains
silicon as their component or as a carrier. Silicon is usually
supplied from such a compound as silica sol or silica gel.
[0006] In JP patent publication 11-179206, in order to modify a
silica as a raw material before being added, a silica sol having a
pH not more than 5 is added to a slurry, and the slurry is prepared
in acidic condition.
[0007] In JP patent publications 49-3498, 48-503, 48-514, etc.,
catalysts containing fumed silica as silicon raw material are
disclosed. Fumed silica is particulate anhydrous silica produced by
reacting a volatile compound containing silica in a vapor phase,
and has different properties from silica gel, white carbon or a
substance produced by hydrolysis of sodium silicate.
[0008] In these conventional techniques, silica sol, silica gel or
fumed silica is added partly for the purpose of more effectively
utilizing catalyst activating components. This object is at least
partly fulfilled in these prior arrangements.
[0009] But catalysts using silica sol, silica gel, or fumed silica
are still insufficient in view of the yield, and further
improvement in the catalytic performance is desired.
[0010] In JP patent publication 5-87300, a composite oxide catalyst
in which bismuth subcarbonate containing Na in the form of a solid
solution is used as a Bi raw material is disclosed. In JP patent
publication 6-13096, a composite oxide catalyst in which bismuth
subcarbonate containing one of Mg, Ca, Zn, Ce and Sm in the form of
a solid solution is used as a Bi raw material is disclosed. In JP
patent publication 6-13097, a composite oxide catalyst in which
bismuth subcarbonate containing one of Mg, Ca, Zn, Ce and Sm and Na
in the form of a solid solution is used as a Bi raw material is
disclosed.
[0011] As described, various catalysts have been proposed to
manufacture acrolein (and also acrylic acid as an effective
component) by contact vapor phase oxidation reaction of propylene
with high yield. They mainly relate to the selection of components
forming the catalyst and their ratios. But some of them relate to
the selection of the physical properties of the catalyst or its
reproducible producing method.
[0012] For the latter in particular, for composite oxide catalysts
containing molybdenum (Mo), bismuth (Bi) and iron (Fe), which are
used for oxidation of olefins and ammoxidation reaction too, while
there are not a few proposals about catalytic physical properties
such as surface areas, pore volumes and pore diameters, proposals
that are at a satisfactory level have not yet been found.
[0013] For example, proposals concerning surface areas are
described in JP patent publications 47-21081, 52-10434, 53-5632,
55-36382, 56-24658, 56-28180, 58-29139, and 48-26690, where surface
areas in the range of 1-50 m.sup.2/g are used. But while surface
areas are specified in these publications, some of them are low in
activity in spite of high reaction temperature, and some are low in
the selectivity of acrolein, so that they are not necessarily
satisfactory as industrially feasible catalysts.
[0014] Among proposals concerning pore volumes, there is one
disclosed in JP patent publication 57-119837, in which there is a
description that 0.2-0.4 cc/g is preferable as the pore volume. But
examples thereof concern ammoxidation.
[0015] As for pore diameters, in JP patent publication 57-119837,
there is a disclosure that the average pore radius is preferably
not less than 2000 angstroms, and in JP 58-113141, there is a
disclosure that pores having diameters smaller than 100 angstroms
have to be less than 3%. But any of the catalysts disclosed in
these publications is low in activity and does not have performance
as an industrial catalyst for producing acrolein and acrylic acid
by the oxidation of propylene with high yield.
[0016] For catalysts used in these reactions, as high catalytic
performance as possible is required in view of effective use of oil
resources and rationalization of the steps in the above reactions.
That is, if the raw material conversion or the selectivity improves
by 0.1%, the amount of products obtained will increase on the order
of several hundred to several thousand tons. Thus, improvement in
the catalytic performance such as the raw material conversion or
the selectivity markedly contributes to effective use of oil
resources or rationalization of the steps even if it is a small
improvement.
OBJECT OF THE INVENTION
[0017] Therefore, an object of this invention is to improve the
catalytic performance, such as the raw material conversion and the
selectivity, of a catalyst used in selective reaction such as vapor
phase catalytic oxidation reaction for producing acrolein or
methacrolein from propylene, isobutene or tertiary butanol, vapor
phase contact ammoxidation reaction for producing acrylonitrile or
methacrylonitrile from propylene or isobutene, and vapor phase
catalytic oxidation type dehydrogenation reaction for producing
butadiene from butene.
Structure of the Invention
[0018] Below, details of this invention are described.
[0019] Molybdenum (Mo), bismuth (Bi), silicon (Si), cobalt (Co),
nickel (Ni), iron (Fe), magnesium (Mg), calcium (Ca), zinc (Zn),
cerium (Ce), samarium (Sm), sodium (Na), potassium (K), rubidium
(Rb), cesium (Cs), thallium (Tl), boron (B), phosphorus (P),
arsenic (As), tungsten (W), fluorine (F), chlorine (Cl), bromine
(Br) and iodine (I) are sometimes indicated using the element
symbols in the brackets.
<Specific Surface Area, Pore Volume and Pore Diameter
Distribution of Catalysts>
[0020] First, the inventors of the present application have found
out that the catalyst physical properties are determined not by its
surface area only, its pore volume only or its pore diameter
distribution only, but that in the case of a composite oxide
catalyst for olefin oxidation containing molybdenum and bismuth,
particularly a catalyst for producing acrolein and acrylic acid by
oxidizing propylene, a catalyst which is high in activity and
superior in selectivity of the amount produced of the target
substance is obtainable by comprehensively determining the specific
surface area, pore volume and pore diameter distribution of the
catalyst.
[0021] That is, in a composite oxide catalyst for olefin oxidation
containing molybdenum and bismuth as essential components,
particularly one for producing acrolein and acrylic acid by
oxidizing propylene, if its specific surface area is 5-25
m.sup.2/g, its pore volume is 0.2-0.7 cc/g and for the pore
diameter distribution, the pore volume of the pores of which the
diameters are 0.03-0.1 micrometers is not less than 30%, preferably
45-80%, of the entire pore volume, and further, the pore volume of
the pores of which the diameters are 0.1-1 micrometers is not less
than 20%, preferably 25-60%, of the entire pore volume, the
activity and selectivity of the catalyst improve. Normally, while
pores having smaller diameters contribute greatly to the specific
surface area and the pore volume, in order for them to contribute
to the activity and the selectivity for effective reaction
products, only pores having small diameters are not enough. Only if
pores having diameters in the range of 0.1-1 micrometer coexist,
the catalytic performance improves.
[0022] The specific surface area used here is a surface area of a
catalyst per unit weight which is measured by BET method using
nitrogen absorption. The pore volume and pore diameter distribution
are the pore diameter, pore volume and its distribution as measured
with a porosimeter using a mercury charging method.
<Introduction of Halogen>
[0023] The composite oxide catalyst of this invention contains Mo,
Bi and halogens as component elements.
[0024] While it is not known how such halogens function during the
producing steps of the composite oxide catalyst, or how it exists,
from the facts that they reveal their effects when the amount of
halogens introduced is in a predetermined ratio with respect to Bi,
that the amount of the remaining halogens is very small, and that
the catalytic performance does not depend on the amount of the
remaining halogens, during the heating step carried out when
producing the composite oxide catalyst, the halogens presumably
contribute to the promotion of heat diffusion when producing
bismuth molybdate crystals, which are formed from Mo and Bi, which
increases lattice deficiency of oxygen in the bismuth molybdate
crystals, thereby improving the catalytic performance, particularly
the raw material conversion.
[0025] As such halogens, F, Cl, Br and I can be cited. Among them,
Cl is effective.
[0026] The content of halogens in the composite oxide catalyst is
preferably 0.0005-0.5 atomic weight with respect to 12 atomic
weight of Mo, more preferably 0.0005-0.05 in atomic weight. If its
atomic weight is over 0.5, the catalytic performance may decrease.
On the other hand, while it may be less than 0.0005 atomic weight,
the atomic weight of 0.0005 is the measurement limit in the
combustion absorption ion chromatography for measuring halogen
amounts, and lesser amounts are not measurable, so that it is
impossible to confirm the existence of halogens.
[0027] Also, for the amount of halogens used during preparation of
the composite oxide catalyst, since not the entire amount used
remains in the composite oxide catalyst, it is necessary to use a
larger amount of them. Specifically, it is preferably 25-50000 ppm,
more preferably 50-5000 ppm, further preferably 100-1000 ppm, with
respect to Bi. If it is less than 25 ppm, the effect of introducing
halogens may not appear sufficiently. On the other hand, if it is
over 50000 ppm, deterioration in catalytic performance may result.
The amount introduced is measured with Bi as a reference because,
as will be described later, introduction of halogens is carried out
using bismuth subcarbonate powder containing Bi and halogens, so
that preparation is easier if Bi is used as a reference.
[0028] For the composite oxide catalyst, as component elements, it
is possible to use one or two or more selected from Na, Mg, Ca, Zn,
Ce and Sm.
[0029] It is presumed that if (BiO).sup.+ ions in the bismuth
molybdate crystals produced in the composite oxide catalyst are
replaced by Na.sup.+ ions, Na increases the lattice deficiency of
oxygen. Like Na, elements such as Mg, Ca, Zn and Sm that are
selected in view of ion radii are also considered to increase the
lattice deficiency of oxygen in the bismuth molybdate crystals. In
either case, it is presumed that improvement particularly in the
raw material conversion results from lattice deficiency.
[0030] The content of Na in the composite oxide catalyst is
preferably 0-1 atomic weight, more preferably 0.01-1 atomic weight,
with respect to 12 atomic weight of Mo. If it is more than 1 atomic
weight, catalytic performance may be down. If the addition amount
is less than 0.01 atomic weight, the effect of improvement in the
catalytic performance due to addition of Na may be
insufficient.
[0031] The content of one or more than one component element in the
composite oxidation catalyst that is selected from among Mg, Ca,
Zn, Ce and Sm is preferably 0-2 atomic weight, more preferably
0.01-1 atomic weight, with respect to 12 atomic weight of Mo. If it
is more than 2 atomic weight, the catalytic performance may drop.
If it is less than 0.01 atomic weight, the effect of improvement in
the catalytic performance due to addition of the above component
elements may be insufficient.
[0032] In order to further improve the selectivity in the
respective reactions of the composite oxide catalyst, besides the
above component elements, other atoms such as K, Rb, Cs and Tl are
preferably added. They presumably improve the selectivity by
existing at the boundaries or surfaces of compounds forming the
composite oxide catalyst.
<General Formula of the Catalyst>
[0033] The composite oxide catalyst of this invention is expressed
by the following general formula:
Mo.sub.aBi.sub.bCo.sub.cNi.sub.dFe.sub.eX.sub.fY.sub.gZ.sub.hSi.sub.iO.su-
b.j (wherein X is at least one kind of element selected from the
group consisting of magnesium (Mg), calcium (Ca), zinc (Zn), cerium
(Ce), samarium (Sm) and halogens, Y is at least one kind of element
selected from the group consisting of sodium (Na), potassium (K),
rubidium (Rb), cesium (Cs) and thallium (Tl), and Z is at least one
kind of element selected from the group consisting of boron (B),
phosphorus (P), arsenic (As) and tungsten (W). The letters a-j
indicate atomic ratios of the respective elements, and when a=12,
then b=0.5-7, c=0-10, d=0-10 (where c+d=1-10), e=0.05-3, f=0-2,
g=0.04-2, h=0-3 and i=5-48. The letter j is a numerical value that
satisfies the oxidation state of other elements.) <Process for
Producing the Catalyst>
[0034] The composite oxide catalyst having the specific properties
of this invention is a compound containing the component elements
forming the composite oxide catalyst, and can be produced by
dissolving or dispersing compounds which can be made into an
aqueous solution or suspension (hereinafter referred to as "supply
source compounds for the component elements") into water and
drying, molding and calcining them.
[0035] Also, the composite oxide catalyst having the specific
properties of this invention can be produced by producing a
catalyst precursor powder by heating a dried product obtained by
drying a raw material salt aqueous solution containing as its part
at least one of molybdenum, iron, nickel and cobalt and silica,
then mixing the catalyst precursor powder and a bismuth compound
together with a water-soluble solvent, and drying, forming and
calcining it.
[0036] In the steps of producing the composite oxide catalyst
according to this invention, there are no particular limitations
except that as a supply source compound for the silicon component,
heat-decomposed silica (fumed silica) is used, and as a supply
source compound for the bismuth component, (1) one of bismuth oxide
and bismuth subcarbonate, (2) bismuth subcarbonate containing at
least part of predetermined Na in the form of a solid solution, (3)
a composite carbonate compound of Bi and X which contains at least
part of the components, or (4) a composite carbonate compound of
Bi, Na and X which contains at least part of predetermined Na and X
components are combined.
[0037] Specific examples of the producing process for the composite
oxide catalyst according to this invention are shown below.
[0038] First, to a suitable molybdenum compound, preferably an
aqueous solution of ammonium molybdate, compounds of iron, cobalt
and nickel, preferably aqueous solutions of their nitrates are
added. Next, compounds of sodium, potassium, rubidium, thallium,
boron, phosphorus, arsenic, tungsten, etc., preferably their
water-soluble salts are added in the form of aqueous solutions.
Further, fumed silica is added. As the fumed silica, it is
particularly preferable to use ultra-particulate anhydrous silica
which is produced by hydrolyzing silanes such as silicon
tetrachloride in oxygen-hydrogen flames and has an average primary
particle diameter of 20-50 nm.
[0039] Next, bismuth powder is added. As described above, the
bismuth powder is (1) at least one of bismuth oxide and bismuth
subcarbonate, (2) bismuth subcarbonate containing at least part of
predetermined Na in the form of a solid solution, (3) a composite
carbonate compound of Bi and X which contains at least part of the
components, or (4) a composite carbonate compound of Bi, Na and X
which contains at least part of predetermined Na and X components.
The bismuth supply source compound is a water-insoluble bismuth.
This compound is preferably used in the form of powder. While the
compounds as the raw materials for producing the catalyst may have
a larger particle diameter than powder, in view of the heating step
in which thermal diffusion is to be carried out, they are
preferably small particles. Thus, if the compounds as the raw
materials do not have small particle diameters, they should be
pulverized before the heating step.
[0040] Thereafter, and after sufficiently agitating the slurry
obtained, it is dried. Next, the dried granular or cake-like one is
subjected to heat treatment for a short time in the temperature
range of 250-350.degree. C. in the air. At this time, in the
heat-treated product obtained, while the iron, cobalt and nickel
have already formed salts with acidic oxides, most of the bismuth
compounds are still in the form of raw materials. This fact shows
that the timing of addition of the bismuth compounds is
arbitrary.
[0041] By forming the heat-treated product thus obtained into a
desired shape in the above-described process, and carrying out
final heat treatment for 1-16 hours preferably at a temperature of
450-650.degree. C., a composite oxide catalyst is obtained.
[0042] The raw material salt water solution is an aqueous solution,
slurry or cake containing as catalytic components molybdenum, iron,
at least one of nickel and cobalt, and silica. Preparation of the
raw material salt water solution is generally carried out by
integrating the supply source compounds of the respective component
elements in aqueous solution.
[0043] Manufacture of the composite oxide catalyst comprises the
steps of integrating the supply source compounds of the respective
component elements in aqueous solution and heating it.
[0044] Integration of the supply source compounds of the respective
component elements in aqueous solution means that aqueous solutions
or dispersions of the supply source compounds of the respective
component elements are mixed or aged all at once or stepwise. That
is to say, (a) a process in which the respective supply source
compounds are mixed all at once, (b) a process in which the
respective supply source compounds are mixed all at once and then
aged, (c) a process in which the respective supply source compounds
are mixed stepwise, (d) a process in which stepwise mixing and
aging of the respective supply source compounds are repeated, and a
combination of (a)-(d) are all included in the concept of
integration of the supply source compounds for the respective
component compounds. Aging is "an operation for achieving
acquisition, rise of the necessary physical properties and chemical
properties or progression of a predetermined reaction by treating
industrial raw materials or half-finished products under specific
conditions including a predetermined time and temperature"
(Chemical Dictionary/Kyoritsu Shuppan). In this invention, the
predetermined time is in the range of 10 minutes to 24 hours. The
predetermined temperature is in the range between room temperature
and the boiling point of the aqueous solutions or dispersions.
[0045] Further, such integration does not mean to carry out the
above treatments only for the supply source compounds for the
respective elements, but also the treatment for carrier materials
that may be used as necessary, such as alumina, silica/alumina and
fire-resistant oxides.
[0046] The above-mentioned heating is a heat treatment for forming
oxides and composite oxides of the individual supply source
compounds for the respective component elements, for forming oxides
and composite oxides of composite compounds produced by the
incorporation, or for forming final composite oxides produced.
Heating is not necessarily carried out only once. That is, the
heating may be carried out at every incorporation step shown in
(a)-(d), and may also be carried out additionally after
incorporation. The heating temperature is normally in the range of
200-700.degree. C.
[0047] In the incorporation and the heating, besides them, for
example, drying, pulverization and forming may be carried out
before, after or between them.
[0048] In many cases, the thus obtained powder or the like is
formed into desired shapes as catalyst products by a molding
process such as extrusion, tableting or pelletizing. During
molding, inorganic fibers such as glass fiber or various whiskers,
which are generally known to have an effect of improving the
strength and the degree of powdering of the catalyst, may be added.
In order to control the physical properties of the catalyst with
good reproducibility, additives generally known as powder binders
such as ammonium nitrate, cellulose, starch, polyvinyl alcohol and
stearic acid may be used.
[0049] A supply source compound for the respective elements when
producing the composite oxide catalyst does not refer only to the
compound for each element but may be a compound containing a
plurality of elements (such as ammonium phosphomolybdate containing
Mo and P).
[0050] A Mo-containing compound used to produce such an Mo/Si
incorporated dispersion is not specifically limited so long as it
contains Mo. For example, ammonium paramolybdate, molybdenum
trioxide, molybdic acid, ammonium phosphomolybdate, phosphomolybdic
acid or the like which are used as supply source compounds for Mo
can be cited.
[0051] Among these supply source compounds for Mo, by using the
above Mo/Si incorporated dispersion at least as a part thereof,
catalytic performance of the composite oxide catalyst obtained
further improves.
[0052] The supply source compound for Si may be a compound which
can be dispersed to not more than 10 micrometers by the above
dispersion treatment. For example, silica, colloidal silica, fumed
silica, etc. can be cited. Among them, colloidal silica, which is
high in aqueous dispersibility, is preferable, and fumed silica,
which makes it possible to obtain high selectivity, is further
preferable. These Si supply source compounds may be used in the
form of powder, powder granules or slurry dispersed in liquid. If
they disperse to not more than 10 micrometers in the dispersing
treatment into the aqueous suspension, their shapes are not
limited. That is, they may be masses, granules, powder or
slurry.
[0053] Fumed silica refers to ultra-fine particulate anhydrous
silica, which is produced by hydrolyzing a silane such as silicon
tetrachloride in flames of oxygen and hydrogen. Unlike silica
produced by a wet process, primary particles of fumed silica, which
have been exposed to high temperature in vapor phase, have only
outer surfaces. This is considered to be extremely effective in
good selectivity in the high raw material conversion.
[0054] If such fumed silica is used, its content is preferably
40-100 wt %, more preferably 60-100 wt %, of the entire
Si-containing compounds. If it is less than 40 wt %, the effect of
improvement in the selectivity by the addition of fumed silica may
not be obtained sufficiently.
[0055] Such fumed silica is preferably used in a dispersed state by
applying dispersion treatment to agglomerated particles in an
aqueous dispersion medium beforehand, i.e. in the form of a fumed
silica dispersion. The primary particles of such fumed silica are
in a strongly agglomerated state, so that if they are suspended in
water with a generally used agitating blade, they form agglomerated
particles even in the dispersion medium. In the measurement by the
present inventors, when the primary particles of fumed silica
having an average particle diameter of 7-50 nm was suspended in ion
exchange water with an agitating blade, the average particle
diameter of the agglomerated particles in the water was in the
range of 10-55 micrometers. These agglomerated particles are used
after pulverized to 5 micrometers or less by subjecting them to
dispersion treatment. This, we presume, causes the catalytic
components mixed together with the Si components to be dispersed
finely, so that the raw material conversion dramatically
improves.
[0056] As a method of dispersing agglomerated particles of fumed
silica in an aqueous dispersion medium, any of the principles of
flow of the medium, collision, pressure difference and ultrasonic
waves may be used. For example, a dispersion method using a
rotating shear flow produced by a homogenizer, a homomixer, a
high-shear blender, etc. can be cited. A dispersion method using an
orifice shrunk flow may also be cited. A dispersion method using
ultrasonic waves may also be cited.
[0057] The dispersion time is not particularly limited if it is
sufficient for the agglomerated particles in the aqueous dispersion
medium to be pulverized to an average particle diameter of 0.1-5
micrometers. The dispersion treatment may be repeated a plurality
of times.
[0058] The average particle diameter of the agglomerated particles
of fumed silica in an aqueous dispersion medium after having been
subjected to dispersion treatment is preferably 0.1-5 micrometers,
more preferably 0.15-3 micrometers, further preferably 0.15-1
micrometer, still more preferably 0.15-0.5 micrometer. If it is
greater than 5 micrometers, a sufficient raw material conversion
may not be obtainable. On the other hand, even if it is less than
0.1 micrometer, it is considered to be advantageous in the
catalytic performance. But this is technically difficult and no one
has achieved it yet. The average particle diameter of the
agglomerated particles of fumed silica in the aqueous dispersion
medium was measured by a laser diffraction type particle diameter
distribution measuring method according to the method described in
JIS K 1150. As the measuring instrument, LMS-24 made by Seishin
Enterprise was used. The average particle diameter was 50% diameter
with respect to the volume.
[0059] The physical properties of the fumed silica are not
particularly limited. But the average diameter of the primary
particles is preferably 15-50 nm, more preferably 20-50 nm. While
the average diameter may be greater than 50 nm, such particles are
generally difficult to manufacture, and difficult to obtain. On the
other hand, if it is smaller than 15 nm, the viscosity of the
aqueous suspension will increase, so that operation may be
difficult. The average diameter of the primary particles of fumed
silica is the average value of diameters of 1000-10000 primary
particles as measured on an electron microscopic photo.
[0060] As the aqueous medium used for dispersion of fumed silica in
this invention, ion exchange water, distilled water or the like is
used. In order to stabilize a finely dispersed state of the fumed
silica, various kinds of stabilizers may be added. In view of
nonexistence of impurities, simple steps and economical advantages,
ion exchange water or distilled water is preferably used as it
is.
[0061] The silica concentration in the suspension or dispersion of
the fumed silica is preferably 0.1-60 wt %, more preferably 1-45 wt
%, further preferably 10-30 wt %. If it is less than 0.1 wt %, the
content of water added as a dispersion medium will be excessive, so
that this may be economically disadvantageous in the drying step.
On the other hand, if it is greater than 60 wt %, the fluidity of
the dispersion will worsen extremely. Thus, there are cases in
which mixing with other catalyst components is difficult.
[0062] The chemical properties of the fumed silica are not
particularly limited. But since it is used in an aqueous solution,
one that is not hydrophobic is suitable.
[0063] The mixing molar ratio of the Mo-containing compound and the
Si-containing compound when carrying out incorporation of the
Mo-containing compound and the Si-containing compound in an aqueous
solution is preferably (molar number of Mo contained)/(molar number
of Si contained)=0.001-100, more preferably 0.02-24. If it is
smaller than 0.001, the amount of Mo supplied as an incorporated
substance obtained from the Mo-containing compound and the
Si-containing compound in the composite oxide catalyst will be so
small that there may be cases in which no sufficient catalytic
performance is obtained. On the other hand, if it is greater than
100, the amount of Mo that is not incorporated with the
Si-containing compound will be so large that it will become
difficult to obtain sufficient effects by this invention.
[0064] In this invention, while it is not apparent how improved
catalytic performance reveals, since an aqueous dispersion in which
the Mo-containing compound and the Si-containing compound are
incorporated in an aqueous solution is used, Mo is retained in the
Si-containing compound first. When the supply source compounds for
respective component elements other than Mo and Si, such as Co, Ni,
Fe, etc. are added thereto, Mo retained by Si is gradually
released, so that a precursor of a composite oxide comprising Mo
and component elements other than Mo and Si, such as Co, Ni and Fe
is formed uniformly. And in forming a composite oxide catalyst by
carrying out incorporation in an aqueous solution and heating, the
homogenized precursor also forms a composite oxide as a constituent
component of the catalyst. This is considered to contribute to
improvement in the catalytic performance such as the raw material
conversion and the selectivity.
[0065] As the composite oxide, a composite oxide containing
molybdenum, i.e. a composite oxide of molybdenum and various metals
of component elements other than Mo and Si can be cited. As
specific examples, an Mo--Bi composite oxide, Mo--Co composite
oxide, Mo--Ni composite oxide, Mo--Fe composite oxide, Mo--Mg
composite oxide, Mo--Ca composite oxide, Mo--Zn composite oxide,
Mo--Ce composite oxide, Mo--Sm composite oxide, Mo--Na composite
oxide, Mo--K composite oxide, Mo--Rb composite oxide, Mo--Cs
composite oxide, Mo--Tl composite oxide, Mo--B composite oxide,
Mo--P composite oxide, Mo--As composite oxide, Mo--W composite
oxide, etc. can be cited.
[0066] This composite oxide catalyst is produced by the steps
including incorporation and heating in an aqueous solution of
supply source compounds of the respective component elements
forming the composite oxide catalyst.
[0067] As the supply source compounds, the following can be cited
as specific examples.
[0068] If Bi is used as the component element, as its supply source
compound, bismuth nitrate, bismuth oxide, bismuth subcarbonate, or
the like may be used.
[0069] It may be supplied as bismuth subcarbonate which contains Na
or X component (at least one kind of element selected from the
group consisting of Mg, Ca, Zn, Ce and Sm) in the form of solid
solution. Bismuth subcarbonate which contains Na in the form of
solid solution can be produced by dripping and mixing an aqueous
solution of a water-soluble bismuth compound such as bismuth
nitrate into e.g. an aqueous solution of sodium carbonate or sodium
bicarbonate, and rinsing and drying the obtained precipitate.
Bismuth subcarbonate which contains X component in the form of
solid solution can be produced by dripping and mixing an aqueous
solution comprising water-soluble compounds such as bismuth nitrate
and a nitrate of X component into e.g. an aqueous solution of
ammonium carbonate or ammonium bicarbonate, and rinsing and drying
the obtained precipitate. If sodium carbonate or sodium bicarbonate
is used instead of ammonium carbonate or ammonium bicarbonate, it
is possible to produce bismuth subcarbonate which contains Na and X
component in the form of solid solution.
[0070] The Bi or the composite carbonate compound of Bi and Na is
preferably used in the form of powder. These compounds as raw
materials for producing catalysts may be particles larger than
powder. But in view of the heating step for thermal diffusion, they
are preferably smaller particles. Thus, if the composite carbonate
compound of Bi and Na is not powder, it is desirably subjected to
pulverizing treatment before the heating step.
[0071] Further, if Na is used as a component element, as its supply
source compound, sodium nitrate or borax may be used. It is also
possible to supply it in the form of solid solution contained in
bismuth subcarbonate. If a composite carbonate compound of Bi and
Na is used, it is possible to further improve the catalytic
performance of the composite oxide catalyst obtained.
[0072] If Fe is used as a component element, as its supply source
compound, ferric nitrate, ferric sulfate, ferric chloride, ferric
acetate or the like may be used. If Co is used as a component
element, as its supply source compound, cobalt nitrate, cobalt
sulfate, cobalt chloride, cobalt carbonate, nickel acetate or the
like can be cited. If Ni is used as a component element, as its
supply source compound, nickel nitrate, nickel sulfate, nickel
chloride, nickel carbonate, nickel acetate or the like can be
cited.
[0073] If X component (at least one kind of element selected from
the group consisting of Mg, Ca, Zn, Ce and Sm) is used as a
component element, as its supply source compound, a nitrate
compound, sulfate compound, chloride, carbonate compound or acetate
compounds of these elements can be cited. As described above, it
may be supplied in the form of solid solution contained in bismuth
subcarbonate.
[0074] If K is used as a component element, as its supply source
compound, potassium nitrate, potassium sulfate, potassium chloride,
potassium carbonate, potassium acetate or the like can be cited. If
Rb is used as a component element, as its supply source compound,
rubidium nitrate, rubidium sulfate, rubidium chloride, rubidium
carbonate, rubidium acetate or the like can be cited. If Cs is used
as a component element, as its supply source compound, cesium
nitrate, cesium sulfate, cesium chloride, cesium carbonate, cesium
acetate or the like may be used. If Tl is used as a component
element, as its supply source compound, thallous nitrate, thallous
chloride, thallium carbonate, thallous acetate or the like can be
cited.
[0075] If B is used as a component element, as its supply source
compound, borax, ammonium borate, boric acid or the like can be
cited. If P is used as a component element, as its supply source
compound, ammonium phosphomolybdate, ammonium phosphate, phosphoric
acid, phosphorus pentoxide or the like can be cited. If As is used
as a component element, as its supply source compound, diarceno 18
ammonium molybdate, diarceno 18 ammonium tungstate or the like can
be cited. If W is used as a component element, as its supply source
compound, ammonium paratungstate, tungsten trioxide, tungstic acid,
phosphotungstic acid or the like can be cited.
[0076] As a supply source compound for Si, one used in the
preparation of the Mo/Si incorporated aqueous dispersion is used.
But besides this aqueous dispersion, the above raw material
compounds may be added.
[0077] Specific examples of the process for producing the composite
oxide catalyst shown by the general formula (I) are shown below. At
the time the above patent documents and others became known, it is
believed that from these specific examples, other specific examples
were obvious to a person of ordinary skill in the art.
[0078] First, an Mo-containing compound such as ammonium
paramolybdate and an Si-containing compound such as fumed silica
are incorporated in an aqueous solution to manufacture an
incorporated dispersion.
[0079] With this Mo/Si incorporated dispersion as a supply source
compound for Mo and Si, supply source compounds for e.g. Fe, Co,
Ni, Mg, Ca, Zn, Ce, Na, K, Rb, Cs, Ti, B, P, As or W, for example,
their water-soluble salts are added. And the supply source compound
for Bi and the supply source compound for Na, preferably composite
carbonate compounds of Bi and Na are added.
[0080] And after the suspension or slurry obtained has been
agitated sufficiently, it is dried. The dried particulate or
cake-like one is subjected to heat treatment for a short time in a
temperature range of 250-350.degree. C. in the air. The primary
heat treated product thus obtained is formed into a desired shape
by such a method as extrusion molding, tablet molding or carrier
molding. Next this molded product is preferably subjected to final
heat treatment under the temperature conditions of 450-650.degree.
C. for about 1-16 hours. Thus, the composite oxide catalyst
according to this invention is produced.
[0081] If bismuth subcarbonate containing Na is used as a supply
source compound for Bi and Na, in the primary heat-treated product
obtained by the short heat treatment, while iron, cobalt and nickel
had already formed salts with acidic oxides, most part of the
bismuth subcarbonate containing Na still showed the form of raw
materials. This means that the addition timing of the bismuth
subcarbonate is not limited to before the short-time heat treatment
but may be after the short-time heat treatment.
[0082] On the other hand, as for the addition timing of the Mo/Si
incorporated aqueous dispersion, since it is supplied as an aqueous
dispersion, the effect is exhibited by adding in the step before
the short-time heat treatment.
[0083] The adding amounts of the respective supply source compounds
in the above producing process may be set according to the
constitution ratio of the constituent elements of the composite
oxide catalyst expressed by the above general formula (I).
[0084] If the composite oxide catalyst expressed by the general
formula (I) is produced by a process comprising incorporating the
supply source compounds of the respective component elements into a
composite in an aqueous solution and subjecting the composite to
heat treatment, it is prepared by, after going through a pre-step
in which a catalytic precursor is produced by heat-treating a raw
material salt solution containing at least one of molybdenum
equivalent to a partial atomic ratio (a.sub.1) of the entire atomic
ratio (a) of the molybdenum of the general formula (I), iron,
nickel and cobalt, and silica, or a dried product obtained by
drying it, going through an after-step in which the catalytic
precursor, molybdenum equivalent to the remaining atomic ratio
(a.sub.2) in which the ratio a.sub.1 is subtracted from the whole
atomic ratio (a) of the general formula (I), and a bismuth compound
are incorporated together with an aqueous solvent, dried and
calcined.
[0085] The ignition loss of the catalyst precursor obtained after
heat treatment is preferably 0.5-5 wt %, more preferably 1-3 wt %.
By determining the ignition loss in this range, it is possible to
obtain a catalyst that is high in the raw material conversion and
the selectivity. The ignition loss is a value given by the
following formula: Ignition
loss(%)=[(W.sub.0-W.sub.1)/W.sub.0].times.100
[0086] W.sub.0: weight (g) of the catalyst precursor after drying
three hours at 150.degree. C. to remove adhering water content
[0087] W.sub.1: weight (g) of the catalyst precursor after heating
it another two hours at 500.degree. C. after removing adhering
water content
[0088] The entire atomic ratio a of the molybdenum in the catalyst
of this invention is 12, which is divided into the atomic ratios
a.sub.1 and a.sub.2 for the pre- and after-steps and incorporated.
The values of the atomic ratios a.sub.1 and a.sub.2 at this time
are preferably in the following relation. That is, a.sub.1 is a
value that satisfies 1<a.sub.1/(c+d+e)<3, and a.sub.2 is a
value that satisfies 0<a.sub.2/b<8.
[0089] Next, as supply source compounds containing Bi and halogens,
as essential components, and as optional components, Na, and/or
component elements consisting of one or two or more selected from
Mg, Ca, Zn, Ce and Sm (hereinafter abbreviated to "supply source
compounds for Bi or the like"), a composite carbonate compound of
Bi containing component elements consisting of halogens as
essential components, and Na and/or one or two or more selected
from Mg, Ca, Zn, Ce and Sm as optional components (which are
hereinafter abbreviated to "halogens") can be cited. As examples
thereof, (water-insoluble) bismuth subcarbonate containing halogens
or the like can be cited. This compound can be produced by dripping
and mixing a water-soluble bismuth compound such as bismuth nitrate
into a mixed solution of an aqueous solution of a carbonate and/or
a bicarbonate such as ammonium carbonate or ammonium bicarbonate,
and an aqueous solution of a water-soluble halogenated substance
such as halogenated ammonium, and rinsing and drying the thus
obtained precipitate.
[0090] In order for it to contain Na, an aqueous solution of sodium
carbonate or sodium bicarbonate may be used as a carbonate and/or a
bicarbonate, and as a halogenated substance, an aqueous solution of
halogenated sodium may be used. Further, in order for it to contain
one or two or more selected from Mg, Ca, Zn, Ce and Sm, an aqueous
solution or the like of nitrates of these elements may be used by
mixing in an aqueous solution of a water-soluble bismuth compound
such as bismuth nitrate. The addition amount of Bi, Na, Mg, Ca, Zn,
Ce or Sm at this time is adjusted according to the content of the
composite oxide catalyst. The amount of the halogens is adjusted
according to the below-described amount.
[0091] Bismuth subcarbonate containing the water-insoluble halogens
or the like is preferably used in the form of powder. These
compounds as raw materials for producing the catalyst may be of
larger particles than powder, but in view of the heating step in
which heat diffusion is carried out, they are preferably of small
diameters. Thus, if these compounds as raw materials are not of
small particles, they should be pulverized before the heating
step.
[0092] Specific examples of the producing method of the composite
oxide catalyst shown by the above general formula (1) are shown
below, e.g. for the case in which Cl is used as a halogen. At the
time when the above-described patent documents are known, from
these specific examples, other specific examples are believed to
have been obvious to a person of ordinary skill in the art.
[0093] First, to a suitable supply source compound for Mo, such as
an aqueous solution of ammonium paramolybdate, a supply source
compound for Fe, Co and Ni, such as an aqueous solution of their
respective nitrates is added. Further, supply source compounds for
Na, K, Cs, Rb, Tl, B, P, As and W, such as their respective
water-soluble salts are added to this aqueous solution. Further, as
necessary, a supply source compound for Si such as particulate or
colloidal silica or fumed silica is added. Thus, a supply source
compound aqueous solution or suspension for Mo or the like is
prepared.
[0094] Next, as a composite carbonate compound of Bi containing
halogens or the like, bismuth subcarbonate containing halogens or
the like is prepared.
[0095] This is obtained by preparing an aqueous solution of a
bismuth-containing compound, e.g. bismuth nitrate, dripping and
mixing it into a mixed solution of an aqueous solution of a
Cl-containing compound such as ammonium chloride and an aqueous
solution of a carbonate ion or bicarbonate ion-containing compound
such as ammonium carbonate or ammonium bicarbonate, and rinsing and
drying the thus obtained precipitate. In order for it to contain Na
as an optional component, sodium chloride may be used as a
Cl-containing compound, or as a carbonate ion- or bicarbonate
ion-containing compound, sodium carbonate or sodium bicarbonate may
be used. In order for it to contain Mg, Ca, Zn, Ce, Sm or the like,
an aqueous solution of e.g. nitrates thereof may be used by mixing
with an aqueous solution of bismuth nitrate. By this preparation
method, Na and Mg, Ca, Zn, Ce or Sm is contained in bismuth
subcarbonate containing halogens or the like.
[0096] Next, powder of bismuth subcarbonate containing halogens or
the like is mixed into an aqueous solution or suspension of the
supply source compound for Mo or the like. And after sufficiently
agitating the suspension or slurry obtained, it is dried. The dried
granular or cake-like one is subjected to a short-time heat
treatment in the air in the temperature range of 250-350.degree.
C.
[0097] The thus obtained primary heat-treated product is formed
into a desired shape by extrusion molding, tablet molding or
carrier molding. Next, the thus molded product is preferably
subjected to final heat treatment under the temperature conditions
of 450-650.degree. C. for 1-16 hours. The composite oxide catalyst
according to this invention is thus produced.
[0098] In the primary heat-treated product obtained by such
short-time heat treatment, while iron, cobalt and nickel had
already formed salts with acidic oxides, most part of the bismuth
subcarbonate containing halogens or the like was in the form of raw
material. This means that the addition timing for the bismuth
subcarbonate containing halogens or the like is not limited to
before the short-time heat treatment, but may be after the
short-time heat treatment.
[0099] Thus, besides the method in which, as described above,
comprehensive integration and short-time or long-time heat
treatment are carried out, i.e. after mixing all of the supply
source compounds, the mixture is heated, a method may be used in
which after integrating and heating the supply source compounds
other than the composite carbonate compound of Bi containing
halogens or the like, the supply source compound for Si in an
aqueous solution, the composite carbonate compound of Bi containing
halogens or the like and the supply source compound for Si are
mixed, and after molding, they are incorporated and heated. Since
Si plays the role of a carrier, there will be no problem no matter
in whichever stage it is added.
[0100] The addition amounts of the respective supply source
compounds in the above producing method may be set according to the
constituent ratio of the constituent elements of the composite
oxide catalyst shown by the general formula (1).
[0101] In producing powder of bismuth subcarbonate containing
halogens or the like, the addition amounts of the Bi-containing
compound, Na-containing compound and a compound containing at least
one kind of Mg, Ca, Zn, Ce and Sm may be set so that the amounts of
Bi, Na, Mg, Ca, Zn, Ce or Sm will meet the constituent ratio of the
constituent elements of the composite oxide catalyst expressed by
the general formula (I). For the addition amount of the
Cl-containing compound, it is necessary to introduce it in a
greater amount because not all of Cl introduced remains in the
composite oxide catalyst. Specifically, it is preferably added such
that the Cl amount will be 25-50000 wt ppm, preferably 50-5000 wt
ppm, more preferably 100-1000 wt ppm, with respect to Bi. If it is
less than 25 wt ppm, when bismuth molybdate crystals are formed, it
will not sufficiently contribute to the promotion of thermal
diffusion, so that the lattice deficiency of oxygen in the bismuth
molybdate crystals may not increase sufficiently. On the other
hand, if it is greater than 50000 wt ppm, deterioration in the
catalyst performance may result.
[0102] The atomic number of halogens in the composite oxide
catalyst expressed by the general formula (I) in the above
producing process, when Mo=12, is preferably 0-0.5, more preferably
0.0005-0.5 as described above. If the value j is greater than 0.5,
the catalyst performance may decrease. On the other hand, the value
j may be zero, that is, halogens may not be present in the
composite oxide catalyst expressed by the general formula (1),
which is obtained by the above producing process. If the value j
exceeds 0 and is less than 0.0005, this is less than the
measurement limit in the combustion absorption ion chromatography
for measuring halogen amounts, and is judged as the value is 0.
Even if the value is in the range of 0-0.0005, since halogens are
added during preparation of the catalyst in the above producing
process, it sufficiently contributes to the promotion of thermal
diffusion when forming bismuth molybdate crystals, thus
sufficiently increasing the lattice deficiency of oxygen in the
bismuth molybdate crystals. Thus, in this producing process, even
if the halogen amount in the composite oxide catalyst finally
obtained is not more than the detection limit, the object of this
invention is achieved.
[0103] The composite oxide catalyst produced in this process can be
used for various vapor phase catalytic oxidation reactions carried
out in the presence of molecular oxygen.
[0104] As specific examples of the vapor phase catalytic oxidation
reaction mentioned here, as described above, the reaction in which
acrolein or methacrolein is produced from propylene, isobutene or
tertiary butanol, the reaction in which acrylonitrile or
methacrylonitrile is produced from propylene or isobutene in the
presence of ammonia, the reaction in which butadiene is produced
from butene, etc. can be cited.
[0105] The vapor phase catalytic oxidation reaction using the
composite oxide catalyst according to this invention is carried out
by introducing as the raw material gas composition a mixture gas
comprising 1-10 vol % of propylene, 5-18 vol % of molecular oxygen,
0-60 vol % of steam, and 20-70 vol % of inert gas such as nitrogen
or carbon dioxide gas onto the catalyst prepared as described above
in the temperature range of 250-450.degree. C. under the pressure
from atmospheric pressure to 10 atm for the contact period of
0.5-10 seconds.
EXPERIMENT EXAMPLES
[0106] The definitions of the propylene conversion, acrolein
selectivity, acrylic acid selectivity, acrolein yield, acrylic acid
yield, and total yield are as follows: Propylene conversion(molar
%)=(molar number of the reacted propylene/molar number of the
supplied propylene).times.100 Acrolein selectivity(molar %)=(molar
number of the acrolein produced/molar number of the reacted
propylene).times.100 Acrylic acid selectivity(molar %)=(molar
number of the acrylic acid produced/molar number of the reacted
propylene).times.100 Acrolein yield(molar %)=(molar number of the
acrolein produced/molar number of the supplied propylene).times.100
Acrylic acid yield(molar %)=(molar number of the acrylic acid
produced/molar number of the supplied propylene).times.100 Total
yield(molar %)=acrolein yield(molar %)+acrylic acid yield (molar %)
<Effect Confirmation Experiments by Physical Properties Such as
Specific Surface Area>
Experiment Example 1
[0107] First, 94.1 g of ammonium paramolybdate was dissolved in 400
ml of pure water under heating. Next, 7.18 g of ferric nitrate,
25.8 g of cobalt nitrate and 37.8 g of nickel nitrate were
dissolved in 60 ml of pure water under heating. These solutions
were gradually mixed while agitating. Next, 0.85 g of borax and
0.36 g of potassium nitrate were dissolved into 40 ml of pure water
while heating, and added to the above slurry. Next, 48 g of
heat-decomposed silica (fumed silica)(having an average primary
particle diameter of 40 nm) was added and sufficiently agitated.
Next, 58.1 g of bismuth subcarbonate which contains 0.57% Na in the
form of solid solution was added and mixed by agitating. After heat
drying of the slurry, it was subjected to thermal treatment at
300.degree. C. for an hour in an aerial atmosphere. The particulate
solid obtained was formed into tablets having a diameter of 5 mm
and a height of 4 mm by the use of a small molding machine. Next,
they were calcined at 500.degree. C. for four hours to form a
composite oxide catalyst.
[0108] The atomic ratio of the composite oxide catalyst as
calculated from raw materials used was as follows:
Mo:Bi:Co:Ni:Fe:Na:B:K:Si=12:5:2:3:0.4:0.39:0.2:0.08:18
Experiment Example 2
[0109] 94.1 g of ammonium paramolybdate was dissolved in 400 ml of
pure water under heating. Next, 7.18 g of ferric nitrate, 25.8 g of
cobalt nitrate and 37.8 g of nickel nitrate were dissolved in 60 ml
of pure water under heating. These solutions were gradually mixed
while agitating.
[0110] Next, 0.85 g of borax and 0.36 g of potassium nitrate were
dissolved into 40 ml of pure water while heating, and added to the
above slurry. Next, 48 g of heat-decomposed silica (having an
average primary particle diameter of 40 nm) was added and
sufficiently agitated. After heat drying of the slurry, it was
subjected to thermal treatment at 300.degree. C. for an hour in an
aerial atmosphere. The particulate solid obtained was pulverized
and dispersed in a solution of 150 ml of pure water to which 10 ml
of ammonia solution was added. Next, 58.1 g of bismuth subcarbonate
which contained 0.52% of Na in the form of solid solution was added
and mixed by agitating. After heat drying of the slurry, the
particulate solid obtained was formed into tablets having a
diameter of 5 mm and a height of 4 mm by use of a small molding
machine. Next, they were calcined at 500.degree. C. for four hours
to form a catalyst.
[0111] The catalyst was a composite oxide having the following
atomic ratio as calculated from the raw materials used:
Mo:Bi:Co:Ni:Fe:Na:B:K:Si=12:5:2:3:0.4:0.37:0.2:0.08:18
Experiment Example 3
[0112] 54 g of ammonium paramolybdate was dissolved in 250 ml of
pure water under heating. Next, 7.18 g of ferric nitrate, 25.8 g of
cobalt nitrate and 37.8 g of nickel nitrate were dissolved in 60 ml
of pure water under heating. These solutions were gradually mixed
while agitating.
[0113] Next, 48 g of heat-decomposed silica was added and
sufficiently agitated. After heating and drying the slurry, it was
subjected to thermal treatment at 300.degree. C. for an hour in an
aerial atmosphere. The particulate solid obtained as a catalyst
precursor (ignition loss: 1.3 wt %) was pulverized, and dispersed
in a solution which 40.1 g of ammonium paramolybdate was dissolved
in 150 ml of pure water adding 10 ml of an ammonia solution. Next,
0.85 g of borax and 0.36 g of potassium nitrate were dissolved into
40 ml of pure water, and added to the slurry. Next, 58.1 g of
bismuth subcarbonate which contained 0.45% of Na in the form of
solid solution was added and mixed by agitating.
[0114] After heat drying of the slurry, the particulate solid
obtained was formed into tablets having a diameter of 5 mm and a
height of 4 mm by the use of a small molding machine. Next, they
were calcined at 500.degree. C. for four hours to form a
catalyst.
[0115] The catalyst was a composite oxide having the following
atomic ratio as calculated from the raw materials used:
Mo:Bi:Co:Ni:Fe:Na:B:K:Si=12:5:2:3:0.4:0.35:0.2:0.08:18
[0116] The atomic ratios a.sub.1 and a.sub.2 of molybdenum during
preparation were 6.9 and 5.1 respectively.
Comparative Experiment Example 1
[0117] Except that colloidal silica was used as the silica raw
material, preparation of a composite oxide catalyst was made in the
same manner as in Experiment Example 1. Table 1 shows the results
of measurement of physical properties of the composite oxide
catalyst obtained such as the specific surface area, and the
results of oxidation reaction of propylene carried out using the
composite oxide catalyst obtained.
Comparative Experiment Example 2
[0118] Except that in preparing a catalyst having the same
composition as in Experiment Example 2, the bismuth raw material
was added simultaneously with the other raw materials, and
colloidal silica was used as the silica raw material, preparation
was made in the same manner as in Experiment Example 2. The results
of measurement of physical properties of the composite oxide
catalyst obtained such as the specific surface area, and the
results of oxidation reaction of propylene carried out using the
composite oxide catalyst obtained are shown in Table 1.
Comparative Experiment Example 3
[0119] A catalyst having the same composition as in Experiment
Example 3 was prepared as follows. 94.1 g of ammonium paramolybdate
was dissolved in 400 ml of pure water under heating. Next, 7.18 g
of ferric nitrate, 25.8 g of cobalt nitrate and 37.8 g of nickel
nitrate were dissolved in 60 ml of pure water under heating. These
solutions were gradually mixed while agitating.
[0120] Next, 0.85 g of borax and 0.36 g of potassium nitrate were
dissolved into 40 ml of pure water while heating, and added to the
above slurry. Next, 240 g of colloidal silica (SiO.sub.2 content 20
wt %) was added and sufficiently agitated. After heat drying of the
slurry, it was subjected to thermal treatment at 300.degree. C. for
an hour in an aerial atmosphere. The particulate solid obtained was
pulverized and dispersed in a solution of 150 ml of pure water
adding 10 ml of an ammonia solution. Next, 58.1 g of bismuth
subcarbonate which contains 0.45% of Na in the form of solid
solution was added and mixed by agitating. After heat drying of the
slurry, the particulate solid obtained was formed into tablets
having a diameter of 5 mm and a height of 4 mm by the use of a
small molding machine. Next, they were calcined at 500.degree. C.
for four hours to form a catalyst. Using this composite oxide
catalyst, which was produced in the same manner as in Experiment
Example 3 except that the supply source of the molybdenum component
was added not separately from but simultaneously with the X, Y and
Z components and prepared, and that as the silica raw material,
colloidal silica was used, oxidation reaction of propylene was
carried out in the same manner as in Experiment Example 3. The
results thereof are shown in Table 1.
(Measurement of Physical Properties of the Composite Oxide Catalyst
of Experiment Examples 1-3 and Comparative Experiment Examples
1-3
[0121] The specific surface area, pore volume and pore distribution
of the composite oxide catalysts prepared as above were measured as
follows. The results are shown in Table 1.
[0122] The specific surface area was measured by BET method using
nitrogen absorption. As the measuring device, Type AMS-8000 made by
Ohkura Riken was used.
[0123] The pore volume and pore distribution were measured by a
mercury charging method. For the measuring device, Pore Sizer
9310-PC2 made by Shimadzu was used.
(Oxidation Reaction of Propylene)
[0124] Using the composite oxide catalysts prepared as above,
oxidation reaction of propylene was carried out and the propylene
conversion, acrolein yield and acrylic acid yield were
calculated.
[0125] Oxidation reaction of propylene was carried out by charging
20 ml of composite oxide catalyst into a reaction tube with a
jacket for a nitrate heating media and having an inner diameter of
15 mm and made of stainless steel, and passing a raw material gas
having 10% of propylene concentration, 17% of steam concentration
and 73% of air concentration under atmospheric pressure in a
reaction temperature of 310.degree. C. with the contact period at
2.0 seconds for Experiment Example 1 and Comparative Experiment
Example 1, 305.degree. C. with the contact period at 1.8 seconds
for Experiment Example 2 and Comparative Experiment Example 2, and
300.degree. C. with the contact period at 1.8 seconds for
Experiment Example 3 and Comparative Experiment Example 3. The
results are shown in Table 1.
[0126] In Table 1, the rate of the pore volume was the rate of the
volume of the pores having diameters in the range of 0.03-0.1 .mu.m
or in the range of 0.1-1 .mu.m relative to the entire pore volume.
TABLE-US-00001 TABLE 1 Rate of Rate of Yield Specific pore pore
Yield of surface Pore volume volume Propylene of acrylic area
volume (0.03.about.0.1 .mu.m) (0.1.about.1 .mu.m) conversion
acrolein acid EEI* 1 18.8 0.35 68 23 98.2 90.3 4.5 EEI* 2 17.7 0.36
63 28 98.0 90.3 4.3 EEI* 3 17.0 0.36 60 35 99.0 90.7 4.6 CEE** 1
29.0 0.32 70 10 98.1 88.2 4.1 CEE** 2 28.9 0.32 69 10 95.5 86.4 3.3
CEE** 3 27.5 0.33 68 11 96.5 87.3 3.4 *Experiment Example according
to the Invention **Comparative Experiment Example
[0127] For the composite oxide catalysts obtained in Comparative
Experiment Examples 1-3, the specific surface area was excessive,
the pore volume rate for 0.1-1 .mu.l m was too small, and the
acrolein yield and the acrylic acid yield were low compared with
those of Experiment Examples 1-3.
<Effect Confirmation Experiment as to the Addition Timing of the
Bi Raw Material)
Experiment Example 4
[0128] 94.1 g of ammonium paramolybdate was dissolved in 400 ml of
pure water under heating. Next, 7.18 g of ferric nitrate, 25.8 g of
cobalt nitrate and 37.8 g of nickel nitrate were dissolved in 60 ml
of pure water under heating. These solutions were gradually mixed
while agitating.
[0129] Next, 0.85 g of borax and 0.36 g of potassium nitrate were
dissolved into 40 ml of pure water while heating, and added to the
above slurry. Next, 64 g of silica was added and sufficiently
agitated. After heat drying of the slurry, it was subjected to
thermal treatment at 300.degree. C. for an hour in an aerial
atmosphere. The particulate solid obtained was pulverized and
dispersed in a solution of 150 ml of pure water adding 10 ml of an
ammonia solution. Next, 58.1 g of bismuth subcarbonate which
contained 0.45% of Na in the form of solid solution was added and
mixed by agitating. After heat drying of the slurry, the
particulate solid obtained was formed into tablets having a
diameter of 5 mm and a height of 4 mm by the use of a small molding
machine. Next, they were calcined at 500.degree. C. for four hours
to form a catalyst.
[0130] The catalyst was a composite oxide having the following
atomic ratio as calculated from the raw materials used:
Mo:Bi:Co:Ni:Fe:Na:B:K:Si=12:5:2:30.4:0.35:0.2:0.08:24
(Oxidation Reaction of Propylene of Experiment Example 4)
[0131] Oxidation reaction of propylene was carried out by charging
20 ml of composite oxide catalyst into a reaction tube with a
jacket for a nitrate heating media and having an inner diameter of
15 mm and made of stainless steel, and passing a raw material gas
having 10% of propylene concentration, 17% of steam concentration
and 73% of air concentration under atmospheric pressure in a
reaction temperature of 310.degree. C. with the contact period at
1.8 seconds. The results are shown in Table 2.
Comparative Experiment Example 4
[0132] Using a composite oxide catalyst having the same composition
as in Experiment Example 3 and prepared in the same manner as in
Experiment Example 3 except that a Bi raw material was added
simultaneously with the other raw materials, oxidation reaction of
propylene was carried out in the same manner as in Experiment
Example 4. The results of the reaction are shown in Table 2.
TABLE-US-00002 TABLE 2 Propylene Yield of Yield of conversion
acrolein acrylic acid EEI* 4 98.5 90.6 4.5 CEE** 4 96.6 88.8 3.8
*Experiment Example according to the Invention **Comparative
Experiment Example
<Effect Confirmation Experiment as to the Addition Timing of the
Mo Component>
Experiment Example 5
[0133] 54 g of ammonium paramolybdate was dissolved in 250 ml of
pure water under heating. Next, 7.18 g of ferric nitrate, 31.8 g of
cobalt nitrate and 31.8 g of nickel nitrate were dissolved in 60 ml
of pure water under heating. These solutions were gradually mixed
while agitating.
[0134] Next, 64 g of silica was added and sufficiently agitated.
After heat drying of the slurry, it was subjected to thermal
treatment at 300.degree. C. for an hour in an aerial atmosphere.
The particulate solid obtained as a catalyst precursor (ignition
loss: 1.4 wt %) was pulverized, and dispersed in a solution which
40.1 g of ammonium paramolybdate was dissolved in 150 ml of pure
water adding 10 ml of an ammonium solution. Next, 0.85 g of borax
and 0.36 g of potassium nitrate were dissolved into 40 ml of pure
water under heating, and added to the slurry. Next, 58.1 g of
bismuth subcarbonate which contained 0.45% of Na in the form of
solid solution was added and mixed by agitating.
[0135] After heat drying of the slurry, the particulate solid
obtained was formed into tablets having a diameter of 5 mm and a
height of 4 mm by the use of a small molding machine. Next, they
were calcined at 500.degree. C. for four hours to form a
catalyst.
[0136] The catalyst was a composite oxide having the following
atomic ratio as calculated from raw materials used:
Mo:Bi:Co:Ni:Fe:Na:B:K:Si=12:5:2.5:2.5:0.4:0.35:0.2:0.08:24
[0137] The atomic ratios a.sub.1 and a.sub.2 of molybdenum during
preparation were 6.9 and 5.1 respectively.
(Oxidation Reaction of Propylene of Experiment Example 5)
[0138] Oxidation reaction of propylene was carried out by charging
20 ml of composite oxide catalyst into a reaction tube with a
jacket for a nitrate heating media and having an inner diameter of
15 mm and made of stainless steel, and passing a raw material gas
having 10% of propylene concentration, 17% of steam concentration
and 73% of air concentration under atmospheric pressure in a
reaction temperature of 305.degree. C. with the contact period at
1.8 seconds. The results are shown in Table 3.
Comparative Experiment Example 5
[0139] A catalyst having the same composition as in Experiment
Example 5 was prepared as follows. 94.1 g of ammonia paramolybdate
was dissolved in 400 ml of pure water under heating. Next, 7.18 g
of ferric nitrate, 31.8 g of cobalt nitrate and 31.8 g of nickel
nitrate were dissolved in 60 ml of pure water under heating. These
solutions were gradually mixed while agitating.
[0140] Next, 0.85 g of borax and 0.36 g of potassium nitrate were
dissolved into 40 ml of pure water while heating, and added to the
above slurry. Next, 64 g of silica was added and sufficiently
agitated. After heat drying of the slurry, it was subjected to heat
treatment at 300.degree. C. for an hour in an aerial atmosphere.
The particulate solid obtained was pulverized and dispersed in a
solution of 150 ml of pure water adding 10 ml of an ammonia
solution. Next, 58.1 g of bismuth subcarbonate which contained
0.45% of Na in the form of solid solution was added and mixed by
agitating. After heat drying of the slurry, the particulate solid
obtained was formed into tablets having a diameter of 5 mm and a
height of 4 mm by the use of a small molding machine. Next, they
were calcined at 500.degree. C. for four hours to form a catalyst.
Using this composite oxide catalyst, which was prepared in the same
manner as in Experiment Example 5 except that the supply source of
the molybdenum component was added not separately from but
simultaneously with the X, Y and Z components and prepared,
oxidation reaction of propylene was carried out in the same manner
as in Experiment Example 5. The results of the reaction are shown
in Table 3. TABLE-US-00003 TABLE 3 Propylene Yield of Yield of
conversion acrolein acrylic acid EEI* 5 99.1 90.8 4.7 CEE** 5 95.4
87.8 3.6 *Experiment Example according to the Invention
**Comparative Experiment Example
<Effect Confirmation Experiment as to the Addition of
Halogens>
Experiment Example 6
[0141] 94.1 g of ammonium paramolybdate was dissolved in 400 ml of
pure water under heating. Next, 7.18 g of ferric nitrate, 25.8 g of
cobalt nitrate and 38.7 g of nickel nitrate were dissolved in 60 ml
of pure water under heating. These two solutions were gradually
mixed while agitating. Next, to this mixed solution, a solution in
which 0.85 g of borax and 0.36 g of potassium nitrate were
dissolved into 40 ml of pure water while heating, was added and
sufficiently agitated to prepare an aqueous solution of a supply
source compound for Mo or the like.
[0142] Next, 100 g of bismuth nitrate was dissolved into ion
exchange water which was made acidic with nitric acid. Also, 42.0 g
of sodium carbonate and 0.3 g of sodium chloride were dissolved
into ion exchange water under heating. These two solutions were
gradually mixed while sufficiently agitating. After mixing by
agitation, the white precipitate obtained was washed, filtered and
dried. The contents of Cl and Na in the bismuth subcarbonate
obtained, which contained halogens or the like, were 0.18 wt % and
0.52 wt %, respectively.
[0143] Next, to an aqueous solution of the supply source compound
for Mo or the like, 58.1 g of powder of the bismuth subcarbonate
containing 64 g of silica were added and mixed together by
agitating.
[0144] Next, after heat drying of the slurry, it was subjected to
thermal treatment at 300.degree. C. for an hour in an aerial
atmosphere. The particulate solid obtained was formed into tablets
having a diameter of 5 mm and a height of 4 mm by the use of a
small molding machine. Next, they were calcined at 500.degree. C.
for four hours in a muffle furnace to form a composite oxide
catalyst.
[0145] The composition ratios of the metal ingredients of the
composite oxide catalyst as calculated from the raw materials used
was as shown in Table 4. On the other hand, the Cl content in the
composite oxide catalyst was measured by the following method. The
atomic ratio thereof is shown in Table 4.
[0146] Oxidation reaction of propylene was carried out by charging
20 ml of composite oxide catalyst into a reaction tube with a
jacket for a nitrate heating media and having an inner diameter of
15 mm and made of stainless steel, and passing a raw material gas
having 10% of propylene concentration, 17% of steam concentration
and 73% of air concentration under atmospheric pressure with the
contact period at 2.3 seconds. At a reaction temperature of
310.degree. C., the oxidation reaction results shown in Table 5
were obtained.
(Measurement Method of the Cl Content)
[0147] Measurement was made using combustion absorption ion
chromatography. That is, a combustion improver was added to the
analysis specimens, heated to 100.degree. C. to let the gas
produced absorbed into pure water, and determination was made by
ion chromatography.
Comparative Experiment Example 6
[0148] 100 g of bismuth nitrate was dissolved into ion exchange
water which was made acidic with nitric acid. Also, 42.0 g of
sodium carbonate was dissolved into ion exchange water under
heating. These two solutions were gradually mixed while
sufficiently agitating. After mixing by agitation, the white
precipitate obtained was washed, filtered and dried. The Na content
of the bismuth subcarbonate obtained was 0.53 wt %.
[0149] A composite oxide catalyst was prepared in the same manner
as in Experiment Example 6 except that instead of the bismuth
subcarbonate of Experiment Example 6, which contained halogens or
the like, the above bismuth subcarbonate powder containing Na was
used, and oxidation reaction of propylene was carried out. The
composition ratios of the metal ingredients of the composite oxide
catalyst, and the reaction results at the reaction temperature of
310.degree. C. are shown in Table 5.
Experiment Example 7
[0150] 100 g of bismuth nitrate and 25 g of magnesium nitrate were
dissolved into ion exchange water which was made acidic with nitric
acid. Also, 38.1 g of ammonium carbonate and 0.3 g of ammonium
chloride were dissolved into ion exchange water under heating.
These two solutions were gradually mixed while sufficiently
agitating. After mixing by agitation, the white precipitate
obtained was washed, filtered and dried. The Cl and Mg contents of
the bismuth subcarbonate obtained, which contained halogens or the
like, were 0.09 wt % and 0.83 wt %, respectively.
[0151] A composite oxide catalyst was prepared in the same manner
as in Experiment Example 6 except that instead of the bismuth
subcarbonate which contained the halogens or the like described in
Experiment Example 6, bismuth subcarbonate containing the above
halogens or the like was used, and oxidation reaction of propylene
was carried out. The composition ratios of the metal ingredients of
the composite oxide catalyst, and the oxidation reaction results at
the reaction temperature of 310.degree. C. are shown in Table
5.
Comparative Experiment Example 7
[0152] 100 g of bismuth nitrate and 25 g of magnesium nitrate were
dissolved into ion exchange water which was made acidic with nitric
acid. Also, 38.1 g of ammonium carbonate was dissolved into ion
exchange water under heating. These two solutions were gradually
mixed while sufficiently agitating. After mixing by agitation, the
white precipitate obtained was washed, filtered and dried. The Mg
content of the bismuth subcarbonate obtained, which contained Mg,
was 0.83 wt %.
[0153] A composite oxide catalyst was prepared in the same manner
as in Experiment Example 6 except that instead of the bismuth
subcarbonate which contained the halogens or the like described in
Experiment Example 6, the above bismuth subcarbonate, which
contained Mg, was used, and oxidation reaction of propylene was
carried out. The composition ratios of the metal ingredients of the
composite oxide catalyst, and the reaction results at the reaction
temperature of 310.degree. C. are shown in Table 5.
Experiment Example 8
[0154] 100 g of bismuth nitrate and 25 g of calcium nitrate were
dissolved into ion exchange water which was made acidic with nitric
acid. Also, 42 g of sodium carbonate and 0.3 g of sodium chloride
were dissolved into ion exchange water under heating. These two
solutions were gradually mixed while sufficiently agitating. After
mixing by agitation, the white precipitate obtained was washed,
filtered and dried. The Cl, Na and Ca contents of the bismuth
subcarbonate obtained, which contained halogens or the like were
0.09 wt %, 0.45 wt % and 0.30 wt %, respectively.
[0155] A composite oxide catalyst was prepared in the same manner
as in Experiment Example 1 except that instead of the bismuth
subcarbonate which contained the halogens or the like described in
Experiment Example 6, the bismuth subcarbonate which contained the
above halogens or the like was used, and oxidation reaction of
propylene was carried out. The composition ratios of the metal
ingredients of the composite oxide catalyst, and the oxidation
reaction results at the reaction temperature of 310.degree. C. are
shown in Table 5.
Experiment Examples 9-12
[0156] Except that bismuth subcarbonate containing halogens or the
like was prepared such that the kinds and amounts of metals
composited in bismuth subcarbonate containing halogens and the
amounts of chloride ions will be of the values shown in Table 6,
the composite oxide catalysts shown in Table 4 were prepared in the
same manner as in Experiment Example 6. And using these catalysts,
reactions under the same conditions as in Experiment Example 6 were
carried out. Composition ratios of the metal ingredients in the
composite oxide catalysts and the results of oxidation reaction at
a reaction temperature of 310.degree. C. are shown in Table 5.
Comparative Experiment Example 8
[0157] 100 g of bismuth nitrate and 25 g of calcium nitrate were
dissolved in ion exchange water acidified with nitric acid. Also,
42 g of sodium carbonate was dissolved in ion exchange water while
heating. These two solutions were gradually mixed together while
agitating. After agitating and mixing, the white precipitate
obtained was washed, filtered and dried. The Ca and Na contents of
the bismuth subcarbonate obtained, which contained Ca, were 0.30 wt
% and 0.45% respectively.
[0158] Except that the above bismuth subcarbonate powder containing
Ca was used instead of the bismuth subcarbonate containing halogens
described in Experiment Example 6, a composite oxide catalyst was
prepared in the same manner as in Experiment Example 6 and
oxidation reaction of propylene was carried out. The composition
ratios of the metal ingredients of the composite oxide catalyst and
the oxidation reaction results at a reaction temperature of
310.degree. C. are shown in Table 5.
(Results)
[0159] As will be apparent from the results of Experiment Example 3
and Comparative Experiment Example 6, by adding Cl to the composite
oxide catalysts, it was possible to improve the propylene
conversion by 0.3% without influencing the selectivity.
[0160] Also, as is apparent from the results of Experiment Example
7 and Comparative Experiment Example 7, by adding Cl to the
composite oxide catalyst, it was possible to improve the propylene
conversion by 0.8% while suppressing lowering of selectively, so
that it was possible to improve the total yield by 0.4%.
[0161] Further, as will be apparent from the results of Experiment
Example 8 and Comparative Experiment Example 8, by adding Cl to the
composite oxide, it was possible to improve the selectivity by 0.3%
and the propylene conversion by 0.2%, so that it was possible to
improve the total yield by 0.5%.
[0162] Further, effects similar to those in Experiment Example 8
were confirmed in Experiment Examples 9-12 too. TABLE-US-00004
TABLE 4 Composition of catalyst (atomic ratio) Mo Bi Co Ni Fe Na Mg
Ca Zn Ce Sm B K Cl Si EEI* 6 12 5 2 3 0.4 0.4 -- -- -- -- -- 0.2
0.08 0.02 24 EEI* 7 12 5 2 3 0.4 0.1 0.4 -- -- -- -- 0.2 0.08 0.01
24 EEI* 8 12 5 2 3 0.4 0.35 0.1 -- -- -- 0.2 0.08 0.01 24 EEI* 9 12
5 2 3 0.4 0.35 0.2 -- -- -- -- 0.2 0.08 0.01 24 EEI* 10 12 5 2 3
0.4 0.35 -- -- 0.06 -- -- 0.2 0.08 0.01 24 EEI* 11 12 5 2 3 0.4
0.35 -- -- -- 0.03 -- 0.2 0.08 0.01 24 EEI* 12 12 5 2 3 0.4 0.35 --
-- -- -- 0.03 0.2 0.08 0.01 24 CEE** 6 12 5 2 3 0.4 0.4 -- -- -- --
-- 0.2 0.08 -- 24 CEE** 7 12 5 2 3 0.4 0.1 0.4 -- -- -- -- 0.2 0.08
-- 24 CEE** 8 12 5 2 3 0.4 0.35 -- 0.1 -- -- -- 0.2 0.08 -- 24
*Experiment Example according to the Invention **Comparative
Experiment Example
[0163] TABLE-US-00005 TABLE 5 Acrylic Yield of Propylene Acrolein
acid Yield of acrylic Total conversion selectivity selectivity
acrolein acid yield EEI* 6 99.0 91.9 4.6 91.0 4.6 95.6 EEI* 7 98.9
92.9 2.4 91.9 2.4 94.3 EEI* 8 99.2 92.2 4.3 91.5 4.3 95.8 EEI* 9
99.2 92.7 3.6 92.0 3.6 95.6 EEI* 10 99.0 93.5 2.9 92.6 2.9 95.5
EEI* 11 99.3 91.9 4.2 91.3 4.2 95.5 EEI* 12 99.2 91.7 4.3 91.0 4.3
95.3 CEE** 6 98.7 91.9 4.5 90.7 4.4 95.1 CEE** 7 98.1 91.6 4.1 89.9
4.0 93.9 CEE** 8 98.9 91.7 4.7 90.7 4.6 95.3 *Experiment Example
according to the Invention **Comparative Experiment Example
[0164] TABLE-US-00006 TABLE 6 Na Cl content content Content (wt %)
(wt %) Kind (wt %) EEI* 9 0.09 0.45 Mg 0.3 EEI* 10 0.09 0.45 Zn 0.3
EEI* 11 0.06 0.45 Ce 0.3 EEI* 12 0.06 0.45 Sm 0.3 *Experiment
Example according to the Invention **Comparative Experiment
Example
<Effect Confirmation Experiments as to Use of Mo/Si Incorporated
Dispersion>
Experiment Example 13
[0165] 94.1 g of ammonium paramolybdate was dissolved into 400 ml
of pure water under heating. Next, 64 g of Aerosil (made by Nippon
Aerosil) was added into 256 ml of pure water and agitated. These
two solutions (slurry) were gradually mixed and agitated
sufficiently until they turn pale yellow to obtain a water
dispersion. Next, 8.97 g of ferric nitrate, 32.3 g of cobalt
nitrate and 32.3 g of nickel nitrate were dissolved into 60 ml of
ion exchange water under heating, and the mixture was gradually
mixed into the above water dispersion and agitated. To this
mixture, solution in which 1.69 g of borax and 0.45 g of potassium
nitrate were dissolved into 40 ml of ion exchange water while
heating was added and sufficiently agitated.
[0166] Next, 100 g of bismuth nitrate was dissolved into ion
exchange water acidified with nitric acid. Also, 42.0 g of sodium
carbonate was dissolved into ion exchange water while heating.
These solutions were gradually mixed together while sufficiently
agitating. After mixing by agitating, the white precipitate
obtained was washed, filtered and dried. The Na content of the
bismuth subcarbonate obtained was 0.53 wt %.
[0167] 34.7 g of this white bismuth subcarbonate, in which was
composited 0.53 wt % of Na, was added to the above mixture and
agitated and mixed. Next, after this slurry has been heated and
dried, it was subjected to thermal treatment at 300.degree. C. for
an hour in an aerial atmosphere. The particulate solid obtained was
formed into tablets having a diameter of 5 mm and a height of 4 mm
by the use of a small molder. Next, calcining was carried out at
500.degree. C. for four hours in a muffle furnace to form a
catalyst.
[0168] The composition ratios of the metal ingredients of the
catalyst calculated from the raw materials used was as follows.
Mo:Bi:Co:Ni:Fe:Na:B:K:Si=12:3:2.5:2.5:0.5:0.4:0.4:0.1:24
[0169] Oxidation reaction of propylene was carried out at the
reaction temperature of 310.degree. C. by charging 20 ml of this
catalyst into a reaction tube with a jacket for a nitrate heating
media and having an inner diameter of 15 mm and made of stainless
steel, and passing a raw material gas having 10% of propylene
concentration, 17% of steam concentration and 73% of air
concentration under atmospheric pressure with the contact period at
2.0 seconds. The reaction results shown in Table 7 were
obtained.
Comparative Experiment Example 9
[0170] 94.1 g of ammonium paramolybdate was dissolved into 400 ml
of ion exchange water while heating. Next, 8.97 g of ferric
nitrate, 32.3 g of cobalt nitrate and 32.3 g of nickel nitrate were
dissolved into 60 ml of ion exchange water under heating. These
solutions were gradually mixed together by sufficiently agitating.
To this mixture, solution in which 1.69 g of borax and 0.45 g of
potassium nitrate were dissolved into 40 ml of ion exchange water
while heating was added and sufficiently agitated. Next, 58.1 g of
the white bismuth subcarbonate used in Experiment Example 13, in
which 0.53 wt % of Na was composited, was added, and further slurry
in which 64 g of Aerosil (made by Nippon Aerosil) was added to 256
ml of pure water and agitated was added, and agitated and
mixed.
[0171] Next, after this slurry has been heated and dried, it was
subjected to thermal treatment at 300.degree. C. for an hour in an
aerial atmosphere. The particulate solid obtained was formed into
tablets having a diameter of 5 mm and a height of 4 mm by the use
of a small molder. Next, calcining was carried out at 500.degree.
C. for four hours in a muffle furnace to form a catalyst. The
composition ratios of the metal ingredients of the catalyst
calculated from the raw materials used was as follows.
Mo:Bi:Co:Ni:Fe:Na:B:K:Si=12:3:2.5:2.5:0.5:0.4:0.4:0.1:24
[0172] Oxidation reaction of propylene was carried out at the
reaction temperature of 310.degree. C. by charging 20 ml of this
catalyst into a reaction tube with a jacket for a nitrate heating
media and having an inner diameter of 15 mm and made of stainless
steel, and passing a raw material gas having 10% of propylene
concentration, 17% of steam concentration and 73% of air
concentration under atmospheric pressure with the contact period at
2.0 seconds. The reaction results shown in Table 7 were obtained.
TABLE-US-00007 TABLE 7 Acrylic Yield of Propylene Acrolein acid
Yield of acrylic Total conversion selectivity selectivity acrolein
acid yield (%) (%) (%) (%) (%) (%) EEI* 13 98.6 93.7 3.4 92.4 3.4
95.8 CEE** 9 98.1 94.5 2.5 92.7 2.5 95.2 *Experiment Example
according to the Invention **Comparative Experiment Example
(Results)
[0173] As will be apparent from the results of Experiment Example
13 and Comparative Experiment Example 9, by using a predetermined
Mo/Si incorporated dispersion, it was possible to improve the
propylene conversion by about 0.5%, improve the total of the
acrolein selectivity and the acrylic acid selectivity by about
0.1%, and improve the total yield by 0.6%.
<Confirmation Experiment of Effect when Aggregated Particles
have Been Subjected to Dispersion Treatment>
Experiment Example 14
[0174] 94.1 g of ammonium paramolybdate was dissolved into 400 ml
of ion exchange water under heating. Next, 8.97 g of ferric
nitrate, 32.3 g of cobalt nitrate and 32.3 g of nickel nitrate were
dissolved into 60 ml of ion exchange water under heating. These
solutions were gradually mixed together while agitating. To this
mixture, 64 g of Aerosil (made by Nippon Aerosil) was added and
agitated. The aqueous suspension obtained was subjected to
dispersion treatment for 20 minutes in a homogenizer (LK-21, made
by YAMATO). The aggregated particles in the dispersion thus
subjected to dispersion treatment had an average particle diameter
of 0.6 .mu.m. The average particle diameter of the aggregated
particles in the dispersion was measured with LMS-24 made by
Seishin Enterprise.
[0175] Next, 100 g of bismuth nitrate was dissolved into ion
exchange water acidified with nitric acid. Also, 42.0 g of sodium
carbonate was dissolved into ion exchange water under heating.
These solutions were gradually mixed together while agitating.
After agitating and mixing, the white precipitate obtained was
washed, filtered and dried. The Na content of the bismuth
subcarbonate obtained which contained Na was 0.53 wt %.
[0176] Next, to the aqueous suspension after the dispersion
treatment, a solution in which 1.69 g of borax and 0.45 g of
potassium nitrate were dissolved into 40 ml of ion exchange water
under heating was added and sufficiently agitated. Further, 34.7 g
of the above bismuth subcarbonate which contained Na was added and
sufficiently agitated and mixed under the atmospheric pressure.
Next, after the slurry had been heated and dried, it was subjected
to thermal treatment at 300% for an hour in an aerial atmosphere.
The particulate solid obtained was formed to tablets having a
diameter of 5 mm and a height of 4 mm by the use of a small molding
machine, and next, it was calcined in a muffle furnace at
500.degree. C. for four hours to obtain a composite oxide
catalyst.
[0177] The composition ratios of the metal ingredients of the
composite oxide catalyst calculated from the raw materials was as
follows.
Mo:Bi:Co:Ni:Fe:Na:B:K:Si=12:3:2.5:2.5:0.5:0.4:0.4:0.1:24
[0178] Oxidation reaction of propylene was carried out by charging
20 ml of this composite oxide catalyst into a reaction tube with a
jacket for a nitrate heating media and having an inner diameter of
15 mm and made of stainless steel, and passing a material gas
having 10% of propylene concentration, 17% of steam concentration
and 73% of air concentration at atmospheric pressure with the
contact period at 2.0 seconds. At a reaction temperature of
310.degree. C., the reaction results shown in Table 8 were
obtained.
Comparative Experiment Example 10
[0179] Except that dispersion treatment using a homogenizer (LK-21
made by YAMATO) was not carried out, a composite oxide catalyst was
prepared in the same manner as in Experiment Example 14, and
oxidation reaction of propylene was carried out. The composition
ratios of the metal ingredients of the composite oxide catalyst
calculated from the raw material was as follows.
Mo:Bi:Co:Ni:Fe:Na:B:K:Si=12:3:2.5:2.5:0.5:0.4:0.4:0.1:24
[0180] Also, the reaction results at a reaction temperature of
310.degree. C. was as follows:
(Results)
[0181] As will be apparent from the results shown in Experiment
Example 14 and Comparative Experiment Example 10, by carrying out
dispersion treatment, it was possible to improve the propylene
conversion by about 0.9% while substantially keeping the acrolein
selectivity and the acrylic acid selectivity, so that it was
possible to improve the total yield by about 0.7%. TABLE-US-00008
TABLE 8 Acrylic Yield of Propylene Acrolein acid Yield of acrylic
Total conversion selectivity selectivity acrolein acid yield (%)
(%) (%) (%) (%) (%) EEI* 14 98.5 92.3 4.7 90.9 4.6 95.5 CEE** 10
97.6 92.5 4.6 90.3 4.5 94.8 *Experiment Example according to the
Invention **Comparative Experiment Example
<Effect Confirmation Experiment when Fumed Silica was Subjected
to Dispersion Treatment>
Experiment Example 15
[0182] The aqueous suspension in which 320 g of Aerosil (made by
Nippon Aerosil) was added to 1280 ml of ion exchange water so as to
be suspended was subjected to dispersion treatment for 20 minutes
in a homogenizer (LK-21 made by YAMATO). The fumed silica
dispersion after dispersion treatment had an average particle
diameter of 0.3 .mu.m. The average particle diameter of the fumed
silica dispersion was measured with LMS-24 made by Seishin
Enterprise.
[0183] 94.1 g of ammonium paramolybdate was dissolved into 400 ml
of ion exchange water under heating. Next, 8.97 g of ferric
nitrate, 32.3 g of cobalt nitrate and 32.3 g of nickel nitrate were
dissolved into 60 ml of ion exchange water under heating. These
solutions were gradually mixed together while sufficiently
agitating. To this mixture, solution in which 1.69 g of borax and
0.45 g of potassium nitrate were added to 40 ml of ion exchange
water was added and sufficiently agitated.
[0184] Next, 100 g of bismuth nitrate was dissolved into ion
exchange water acidified with nitric acid. Also, 42.0 g of sodium
carbonate was dissolved into ion exchange water under heating.
These solutions were gradually mixed together while agitating
sufficiently. After agitating and mixing, the white precipitate
obtained was washed, filtered and dried. The Na content of the
bismuth subcarbonate obtained which contained Na was 0.53 wt %.
[0185] Next, 34.7 g of the bismuth subcarbonate obtained, which
contained Na, and 320 g of the fumed silica dispersion were added
to an aqueous solution of the above supply source compound, and
agitated and mixed. Next, after this slurry has been heated and
dried, it was subjected to thermal treatment at 300.degree. C. for
an hour in an aerial atmosphere. The particulate solid obtained was
formed to tablets having a diameter of 5 mm and a height of 4 mm by
the use of a small molding machine. Next, it was calcined in a
muffle furnace at 500.degree. C. for four hours to obtain a
composite oxide catalyst.
[0186] The composition ratios of the metal ingredients of the
composite oxide catalyst calculated from the raw materials was as
follows.
Mo:Bi:Co:Ni:Fe:Na:B:K:Si=12:3:2.5:2.5:0.5:0.4:0.4:0.1:24
[0187] Oxidation reaction of propylene was carried out by charging
20 ml of this composite oxide catalyst into a reaction tube with a
jacket for a nitrate heating media and having an inner diameter of
15 mm and made of stainless steel, and passing a material gas
having 10% of propylene concentration, 17% of steam concentration
and 73% of air concentration at atmospheric pressure with the
contact period at 2.0 seconds. At a reaction temperature of
310.degree. C., the reaction results shown in Table 9 were
obtained.
Comparative Experiment Example 11
[0188] 320 g of Aerosil (made by Nippon Aerosil) was added to 1280
ml of ion exchange water so as to be suspended. The average
particle diameter of the suspension was 52 .mu.m.
[0189] Except that the suspension of Aerosil as mentioned above was
used as the supply source compound for Si, a composite oxide
catalyst was prepared in the same manner as in Experiment Example
15, and oxidation reaction of propylene was carried out. The
composition ratios of the metal ingredients of the composite oxide
catalyst calculated from the raw materials was as follows.
Mo:Bi:Co:Ni:Fe:Na:B:K:Si=12:3:2.5:2.5:0.5:0.4:0.4:0.1:24
[0190] The reaction results at a reaction temperature of
310.degree. C. were as shown in Table 9.
Comparative Experiment Example 12
[0191] Except that 64 g of Aerosil (made by Nippon Aerosil) powder
was used as the supply source compound for Si, a composite oxide
catalyst was prepared in the same manner as in Experiment Example
15, and oxidation reaction of propylene was carried out. The
composition ratios of the metal ingredients of the composite oxide
catalyst calculated from the raw materials was as follows.
Mo:Bi:Co:Ni:Fe:Na:B:K:Si=12:3:2.5:2.5:0.5:0.4:0.4:0.1:24
[0192] The reaction results at a reaction temperature of
310.degree. C. were as shown in Table 9. TABLE-US-00009 TABLE 9
Acrylic Yield of Propylene Acrolein acid Yield of acrylic Total
conversion selectivity selectivity acrolein acid yield (%) (%) (%)
(%) (%) (%) EEI* 15 99.0 95.2 1.6 94.2 1.6 95.8 CEE** 11 98.0 94.7
2.4 92.8 2.4 95.2 CEE** 12 97.9 95.2 2.1 93.2 2.1 95.3 *Experiment
Example according to the Invention **Comparative Experiment
Example
(Results)
[0193] As will be apparent from Experiment Example 12 and
Comparative Experiment Examples 11 and 22, by using predetermined
fumed silica, it was possible to improve the propylene conversion
by 1.0-1.1% while substantially keeping the acrolein selectivity
and the acrylic acid selectivity, so that it was possible to
improve the total yield by 0.5-0.6%.
EFFECT OF THE INVENTION
[0194] As described above, according to this invention, as a
catalyst used for selective reaction such as vapor phase catalytic
oxidation reaction for producing acrolein or methacrolein from
propylene, isobutene or tertiary butanol, vapor phase catalytic
ammooxidation reaction for producing acrylonitrile or
methacrylonitrile from propylene or isobutene, and vapor phase
catalytic oxidative dehydrogenation reaction for producing
butadiene from butene, it is possible to provide a catalyst which
has improved catalytic performance such as the raw material
conversion and selectivity.
* * * * *