Method for the preparation of methacrylic acid
AssigneeUbe Industries, Ltd.
InventorsSumio Umemura, Kyoji Ohdan, Kenichi Suzuki, Fumio Adachi
Life of this patent
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Abstract
Methacrylic acid can be produced from methacrolein with a high reaction percentage of methacrolein and a high selectivity percentage of methacrylic acid, by bringing a reaction feed containing methacrolein and molecular oxygen into contact with an oxidation catalyst at a temperature of 200 to 450.degree. C, the oxidation catalyst comprising oxides of molybdenum, phosphorus, calcium, at least one element selected from the group consisting of arsenic, bismuth, tin, titanium, tantalum and boron and, optionally, at least one element selected from the group consisting of antimony, niobium and magnesium.
Claims10
A method for the preparation of methacrylic acid by oxidation of methacrolein, comprising bringing a reaction feed containing methacrolein in vapor phase and molecular oxygen into contact at a temperature of 200.degree.-450.degree. C with an oxidation catalyst consisting of an oxide composition of the formula (I):
- [mo.sub.a P.sub.b Ca.sub.c X.sub.d O.sub.e ] Mo.sub.a P.sub.b Ca.sub.c As.sub.d O.sub.e (I)
- wherein the subscripts a, b, c and d respectively denote the numbers of the respective element atoms, said numbers being within the ranges, a-5 to 15, b = 1 to 3,c = 0.1 to 3, d = 0.1 to 3, and the subscript e represents the number of oxygen atoms which corresponds to the oxides formed from the above mentioned elements and satisfies the average valency of the elements, said number e being within the range of 16 to 60.
A method for the preparation of methacrylic acid by oxidation of methacrolein, comprising bringing a reaction feed containing methacrolein in vapor phase and molecular oxygen into contact at a temperature of 200.degree.-450.degree. C with an oxidation catalyst consisting of an oxide composition of the formula (II):
- [mo.sub.a P.sub.b Ca.sub.c X.sub.f Y.sub.g O.sub.e ] Mo.sub.a P.sub.b Ca.sub.c As.sub.f Y.sub.g O.sub.e (II)
- wherein Y represents at least one member selected from the group consisting of antimony, niobium and magnesium atoms, the subscripts a, b, c, f and g respectively denote the numbers of the respective element atoms, said numbers being within the ranges, a = 5 to 15, b, = 1 to 3, c = 0.1 to 3, f = 0.1 to 3 and g = 0.1 to 3, and the subscript e represents the number of oxygen atoms which corresponds to the oxides formed from the above mentioned elements and satisfies the average valency of the elements, said number e being within a range of 16 to 68.
A method for the preparation of methacrylic acid by oxidation of methacrolein, comprising bringing a reaction feed containing methacrolein in vapor phase and molecular oxygen into contact at a temperature of 200.degree.- 450.degree. C with an oxidation catalyst consisting of an oxide composition of the formula (III):
- mo.sub.a P.sub.b Ca.sub.c As.sub.h Z.sub.i O.sub.e (III)
- wherein Z represents at least one member selected from the group consisting of bismuth, tin, titanium, tantalum, boron, antimony, niobium and magnesium atoms, the subscripts a, b, c, h and i respectively represent the numbers of the respective element atoms, said numbers being within the following ranges, a=5 to 15, b=1 to 3, c=0.1 to 3, h=0.1 to 3, and i =0.1 to 3, and the subscript e represents the number of oxygen atoms which correspond to the oxides formed from the above mentioned elements and satisfies the average valency of the elements involved, the number e being within a range of 16 to 68.
Dependencies are inferred from the claim text.