Mitsubishi Rayon Company, Limited

Hideo Matsuzawa

Hiromichi Ishii

Masao Kobayashi

Kantaro Yamada

Kazuya Okada

Kazuhiro Ishii

Masaaki Kato

Minoru Ikeda

Masato Otani

Hiroshi Matsumura

Teruhiko Yoshioka

Takashi Tokutomi

Yukinobu Sugimoto

Hasao Kobayashi

Shuji Uchida

Hiroshi Sonobe

The gas phase catalytic oxidation of an unsaturated aldehyde with molecular oxygen at 200.degree. to 500.degree. C. to give the corresponding unsaturated carboxylic acid is conducted in the presence of a catalyst represented by the following formula:

Process for the preparation of unsaturated carboxylic acids

At least one olefinic hydrocarbon of 3 to 4 carbon atoms is oxidized catalytically in the gas phase in the presence of molecular oxygen at 200.degree.-450.degree. C. to produce the corresponding aldehyde and acid over a calcined catalyst of the formula Mo.sub.a Sb.sub.b Bi.sub.c Fe.sub.d Ni.sub.e Sn.sub.f X.sub.g Y.sub.h O.sub.i wherein X is at least one alkali metal selected from the group consisting of potassium, rubidium and cesium; Y is at least one metal selected from the group consisting of cobalt, uranium, germanium, tungsten and titanium; a to h are atomic ratios wherein a=12, b=0.2 to 20, c=0.2 to 12, d=0.2 to 12, e=0.2 to 12, f=0 to 20, g=0.01 to 4 and h=0 to 6; and i is determined according to the oxidation states of the metal atoms in the catalyst.

Process for producing unsaturated aldehydes, and unsaturated fatty acids

The gas phase catalytic oxidation of an unsaturated aldehyde with molecular oxygen at 240.degree. to 450.degree. C. to give the corresponding unsaturated carboxylic acid is conducted in the presence of a catalyst of the following formula:

Catalytic process for the preparation of unsaturated carboxylic acid

A method of removing chromium ion from an aqueous solution of an organic acid of an acid concentration of up to 95% which comprises treating the solution with a cation exchange resin at a temperature higher than 55.degree. C.

Method for removing chromium ions from aqueous solutions of organic acids

An olefin having 4 carbon atoms or t-butyl alcohol is catalytically oxidized in the gas phase with molecular oxygen at 200.degree. to 450.degree. C. to give the corresponding unsaturated aldehyde, unsaturated carboxylic acid and/or conjugated diene in the presence of a catalyst having the formula:

Process for producing unsaturated aldehydes and unsaturated carboxylic

A phosphorus-molybdenum-alkali metal-containing catalyst for the gas-phase oxidation of an unsaturated aldehyde to an unsaturated carboxylic acid is regenerated by treating it with an aqueous solution containing ammonia and hydrogen peroxide or ozone.

Method for regenerating an oxidation catalyst

A method for separating and purifying methacrylic acid is disclosed in which an aqueous solution (A) of methacrylic acid containing acetic acid is brought into contact under counter-current flow with a mixed solvent (B) of methyl methacrylate and toluene in a ratio of from 3 : 2 to 1 : 9 by weight, to extract substantially the whole amount of methacrylic acid in solution (A) into mixed solvent (B); after which the methacrylic acid is separated and purified by distillation.

Method of separating and purifying methacrylic acid

The gas phase catalytic oxidation of an unsaturated aldehyde with molecular oxygen at 240.degree. to 450.degree. C to the corresponding unsaturated carboxylic acid is conducted in the presence of a catalyst of the formula:

Catalytic process for the preparation of an unsaturated carboxylic acid

An olefin having 4 carbon atoms or t-butyl alcohol is catalytically oxidized in the gas phase with molecular oxygen at 200 to 450.degree. C to give the corresponding unsaturated aldehyde, unsaturated carboxylic acid and/or conjugated diene in the presence of a catalyst having the formula:

At least one compound from the group of unsaturated hydrocarbons of three to four carbon atoms and t-butyl alcohol is oxidized catalytically in the gas phase in the presence of molecular oxygen at 200.degree.-450.degree. C to produce the corresponding aldehyde or acid over a calcined catalyst of the formula Mo.sub.a Sb.sub.b Bi.sub.c Fe.sub.d Ni.sub.e Sn.sub.f X.sub.g Y.sub.h O.sub.i wherein X is at least one of potassium, rubidium or cesium, Y is at least one of cobalt, uranium, germanium, tungsten or titanium, a to h are atomic ratios wherein a=12, b=0.2 to 20, c=0.2 to 12, d=0.2 to 12, e=0.2 to 12, f=0 to 20, g=0.01 to 4 and h=0 to 6 and i is a value determined by the oxidation state of the metal atoms in the catalyst.An embodiment of the calcined catalyst of the invention has the formula Mo.sub.a Sb.sub.b Bi.sub.c Fe.sub.d Ni.sub.e Sn.sub.f X.sub.g Y.sub.h Z.sub.j O.sub.i wherein X and y are as defined above and Z is palladium and a to j are atomic ratios wherein a=12, b=0.2 to 20, c=0.2 to 12, d=0.2 to 12, e=0.2 to 12, f=0 to 20, g=0.01 to 4, h=0.01 to 3, j=0.01 to 3 and i assumes a value determined by the oxidation states of the metal atoms in the catalyst.

The gas phase catalytic oxidation of an unsaturated aldehyde with molecular oxygen at 240.degree. to 390.degree. C to give the corresponding unsaturated carboxylic acid is conducted in the presence of a catalyst represented by the following formula:

Catalytic process for the preparation of unsaturated carboxylic acids

Acrylic acid or methacrylic acid is prepared by vapor-phase catalytic oxidation of acrolein or methacrolein, with molecular oxygen at a temperature of from 240.degree. to 450.degree. C in the presence of a catalyst represented by the formula:

Process and catalyst for preparing unsaturated carboxylic acid

An olefin having 4 carbon atoms or t-butyl alcohol is catalytically oxidized in the gas phase with molecular oxygen at 200.degree. to 450.degree. C to give the corresponding unsaturated aldehyde, unsaturated carboxylic acid and/or conjugated diene in the presence of a catalyst having the formula:

T-Butyl alcohol is produced by reacting isobutylene with an aqueous organic acid solution in the presence of an acidic ion-exchanger. t-Butyl alcohol can be produced by this process from a mixed gas containing isobutylene and n-butene. The process is also applicable for separation of isobutylene from a mixed gas containing isobutylene and n-butene.

Process for producing tertiary butyl alcohol

Methacrolein is produced by catalytically oxidizing t-butyl alcohol with oxygen by using a catalyst system of MoSbBiFeNi-alkali. Propylene or isobutylene can also be catalytically oxidized with the same catalyst system to produce acrolein or methacrolein. Methacrolein and 1,3-butadiene can simultaneously be produced by catalytically oxidizing a mixture of isobutylene and n-butene with the same catalyst.

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Otake, Japan

Hideo Matsuzawa