Organic compounds -- part of the class 532-570 series – Organic compounds – Carboxylic acids and salts thereof
Reexamination Certificate
2000-05-11
2003-06-24
Killos, Paul J. (Department: 1623)
Organic compounds -- part of the class 532-570 series
Organic compounds
Carboxylic acids and salts thereof
C562S538000, C562S545000, C562S546000, C502S325000
Reexamination Certificate
active
06583316
ABSTRACT:
TECHNICAL FIELD TO WHICH THE INVENTION BELONGS
This invention relates to catalysts for production of unsaturated aldehyde and unsaturated carboxylic acid and to a process for producing unsaturated aldehyde and unsaturated carboxylic acid. More particularly, the invention relates to improved catalysts for producing unsaturated aldehyde and unsaturated carboxylic acid at high yield and with stability over a prolonged period, by vapor phase oxidation of at least one compound selected from the group consisting of propylene, isobutylene, t-butanol and methyl-t-butyl ether; and also to a process for producing unsaturated aldehyde and unsaturated carboxylic acid using the improved catalysts.
CONVENTIONAL TECHNOLOGY
A number of improved catalysts have been proposed for high efficiency production of unsaturated aldehyde and unsaturated carboxylic acid by vapor phase catalytic oxidation reaction of propylene, isobutylene, t-butanol or methyl-t-butyl ether. The most of those proposed catalysts contain molybdenum, bismuth and iron as their chief components.
However, those catalysts still are subject to problems which need to be solved, in respect of yields of unsaturated aldehyde and unsaturated carboxylic acid and the catalyst life. Molybdenum in a catalyst is apt to sublime, which induces irreversible degradation in the catalytic activity. The intended oxidation reaction is extremely exothermic and in the catalyst layers, in particular, at the local abnormally high temperature zone which is referred to as hot spot, molybdenum sublime vigorously. Particularly in heavy load operation aiming at high productivity, naturally the heat accumulation at the hot spot increases to prolong the period during which the catalyst is used under high temperatures. Considering these factors, catalysts having high activity and exhibiting stable performance over a long period are in demand.
On the other hand, various proposals have been also made as to complex oxides whose essential components are cerium and zirconium. Most of these complex oxides are known as additive components to waste gas-combustion catalysts, but it is entirely unknown that such complex oxides whose essential components are cerium and zirconium exhibit effective catalytic activity in production of unsaturated aldehyde and unsaturated carboxylic acid through vapor phase catalytic oxidation of propylene, isobutylene, t-butanol or methyl-t-butyl ether, when used in combination with molybdenum-bismuth-iron-containing catalysts.
OBJECTS OF THE INVENTION
One of the objects of the present invention is to provide catalysts which are useful in production of unsaturated aldehyde and unsaturated carboxylic acid at high yield.
A further object of the present invention is to provide catalysts for unsaturated aldehyde and unsaturated carboxylic acid production, which have long catalyst life and enable stable operation over prolonged period.
Still another object of the present invention is to provide catalysts for unsaturated aldehyde and unsaturated carboxylic acid production which enable stable operation over prolonged period, even under heavy load operation aiming at high productivity.
An additional object of the present invention is to provide a process for producing unsaturated aldehyde and unsaturated carboxylic acid at high yield and with stability over prolonged period, using the above catalysts.
MEANS TO SOLVE THE PROBLEMS
We have discovered that a composition, in which a complex oxide known as catalyst for unsaturated aldehyde and unsaturated carboxylic acid production, containing molybdenum, bismuth and iron as the essential components, is combined with a complex oxide whose essential components are cerium and zirconium, exhibits high catalytic activity in the intended reaction and excellent stability; and that the use of such a composition as a catalyst in said reaction accomplishes the above objects.
Thus, according to the invention, as a catalyst for producing unsaturated aldehyde and unsaturated carboxylic acid through oxidation of at least one compound selected from the group consisting of propylene, isobutylene, t-butanol and methyl-t-butyl ether with molecular oxygen or a molecular oxygen-containing gas at vapor phase, a complex oxide composition characterized by comprising
(A) a complex oxide containing as essential components molybdenum, bismuth and iron, which is known per se as a catalyst for said vapor phase catalytic oxidation reaction, and
(B) a complex oxide containing cerium and zirconium as the essential components, is provided.
According to the present invention, there is also provided, as a catalyst for producing unsaturated aldehyde and unsaturated carboxylic acid through oxidation of at least one compound selected from the group consisting of propylene, isobutylene, t-butanol and methyl-t-butyl ether with molecular oxygen or a molecular oxygen-containing gas at vapor phase, a complex oxide composition which is characterized by having a composition expressed by the following general formula (3):
Mo
a
W
b
Bi
c
Fe
d
Ce
e
Zr
f
A
g
B
h
C
i
D
j
E
k
G
l
O
x
(3)
(wherein Mo is molybdenum; W is tungsten: Bi is bismuth;
Fe is iron; Ce is cerium; Zr is zirconium; A is at least an element selected from nickel and cobalt; B is at least an element selected from alkali metals and thallium; C is at least an element selected from alkaline earth metals; D is at least an element selected from phosphorus, tellurium, antimony, tin, lead, niobium, manganese, arsenic and zinc; E is at least an element selected from silicon, aluminium and titanium; G is at least an element selected from the group consisting of lanthanoide series except cerium; yttrium, copper, indium, chromium and germanium; and O is oxygen; a, b, c, d, e, f, g, h, i, j, k, l and x denote the atomic ratios of Mo, W, Bi, Fe, Ce, Zr, A, B, C, D, E, G and O, respectively, and where a is 12, b is 0-10, c is 0.1-10, d is 0.1-20, e is 0.01-30, f is 0.01-42, g is 2-20, h is 0.001-10, i is 0-10, j is 0-4, k is 0-30, l is 0-7, and x is a numerical value determined by degree of oxidation of each of the elements)
and the cerium and zirconium therein forming a complex oxide.
According to the invention, furthermore, there is provided a process for producing unsaturated aldehyde and unsaturated carboxylic acid through vapor phase oxidation of at least one compound selected from the group consisting of propylene, isobutylene, t-butanol and methyl-t-butyl ether with molecular oxygen or a molecular oxygen-containing gas, in the presence of a catalyst, the process being characterized in that it uses the above-defined complex oxide composition as the catalyst.
EMBODIMENTS OF THE INVENTION
Catalyst (I) for unsaturated aldehyde and unsaturated carboxylic acid production according to the invention is a complex oxide composition which is characterized by comprising
(A) a complex oxide containing as essential components molybdenum, bismuth and iron, which is known per se as a catalyst for producing unsaturated aldehyde and unsaturated carboxylic acid through said vapor phase catalytic oxidation reaction of propylene, isobutylene, t-butanol and methyl-t-butyl ether, and
(B) a complex oxide containing cerium and zirconium as the essential components.
Catalyst (II) for unsaturated aldehyde and unsaturated carboxylic acid production according to another embodiment of the present invention is a complex oxide composition which is characterized by having the composition as expressed by above general formula (3), in which cerium and zirconium form a complex oxide.
First, the Catalyst (I) shall be explained. The component (A) corresponds to a catalyst containing molybdenum, bismuth and iron as the essential components, which is known as a catalyst for unsaturated aldehyde and unsaturated carboxylic acid production by vapor phase oxidation reaction of propylene, isobutylene, t-butanol or methyl-t-butyl ether. While any of known catalysts containing molybdenum, bismuth and iron as the essential components can be used as the component (A), those preferred are expressed by the following general for
Onodera Hideo
Tanimoto Michio
Killos Paul J.
Nippon Shokubai Co. , Ltd.
Sherman & Shalloway
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