Nippon Shokubai Co., Ltd.

Nippon Shokubai Kagaku Kogyo Co., Ltd.

Ikuo Kurimoto

Yukio Aoki

Hideo Onodera

Michio Tanimoto

Tatsuya Kawajiri

Yoshiyuki Nakanishi

Hideto Hashiba

Shigeru Ohno

Youjirou Takahashi

Shigemi Osaka

Hiroyuki Uhara

Shinichi Uchida

Yoji Akazawa

Toshimasa Kushihara

Junichi Toyoda

Hiroyuki Tazaki

Hisashi Yoshikawa

A catalyst for the production of unsaturated aldehyde and unsaturated carboxylic acid by the vapor-phase catalytic oxidation of at least one compound selected from the group consisting of propylene, isobutylene, t-butanol and methyl-t-butyl ether and a method for the production of unsaturated aldehyde and unsaturated carboxylic acid by the use of this catalyst are provided. The catalyst of this invention comprises (A) a catalyst having Mo, Bi and Fe as essential components and used for the production of unsaturated aldehyde and unsaturated carboxylic acid by vapor-phase catalytic oxidation of propylene, isobutylene, t-butanol and/or methyl-t-butyl ether and (B) a solid acid having acid strength (Ho) of not more than -11.93. Since this catalyst excels in catalytic activity and service life, it allows unsaturated aldehyde and unsaturated carboxylic acid to be produced stably at a high yield for a long time.

Catalyst for production of unsaturated aldehyde and unsaturated

A catalyst for the production of methacrylic acid by the vapor-phase catalyst oxidation and/or oxidative dehydrogenation of at least one compound selected rom the group consisting of methacrolein, isobutyl aldehyde, and isobutyric acid and a method for the production of methacrylic acid by the use of this catalyst are provided. The catalyst of this invention comprises (A) a composite oxide having Mo and P as essential components and used for the production of methacrylic acid by vapor-phase catalytic oxidation and/or oxidative dehydrogenation of methacrolein, isobutyl aldehyde, and/or isobutyric acid and (B) a solid acid having acid strength (Ho) of not more than -11.93. Since this catalyst excels in catalytic activity and service life, it allows methacrylic acid to be produced stably at a high yield for a long time.

Catalyst for production of methacrylic acid and method for production of

Process for producing methacrolein and methacrylic acid

A method for the production of methacrylic acid comprising the steps of simultaneously introducing at least one compound selected from the group consisting of methacrolein and isobutyl aldehyde and a molecular oxygen-containing gas into a heat exchanger type shell-and-tube reaction vessel packed with an oxide catalyst containing molybdenum and phosphorus thereby effecting catalytic vapor-phase oxidation reaction and/or catalytic vapor-phase oxidative dehydrogenation reaction and consequently forming methacrylic acid, which method is characterized by having the empty space in the gas outlet part of said reaction vessel with a solid filler.

Method for production of methacrylic acid

A process for producing methacrylic acid, which comprises

Process for producing methacrylic acid

A catalyst for the production of methacrylic acid composed of an inert carrier and a catalytically active substance. The catalytically active substance layer being composed of oxides represented by the following formula (I)

Catalyst for the production of methacrylic acid

An improved process for producing maleic anhydride which comprises catalytically oxidizing benzene with a molecular oxygen-containing gas in the vapor phase in a multitubular heat-exchanger-type reactor. The process is characterized in that

Process for producing maleic anhydride

In a method for the preparation of pyromellitic acid or its anhydride by catalytic vapor phase oxidation of a tetra-C.sub.1 -C.sub.4 -alkylbenzene using a catalyst comprising catalytically active material composed of 1 to 20 parts by weight of V.sub.2 O.sub.5, 99 to 80 parts by weight of TiO.sub.2 and/or SnO.sub.2 and/or ZrO.sub.2, and per one hundred parts by weight of V.sub.2 O.sub.5, TiO.sub.2 and/or SnO.sub.2 and/or ZrO.sub.2 0.02 to 10 parts by weight, calculated as P.sub.2 O.sub.5, of a phosphorus compound, 0.01 to 5 parts by weight, calculated as Nb.sub.2 O.sub.5, of a niobium compound, 0 to 1.2 parts by weight, calculated as oxide, of at least one metal selected from the group consisting of potassium, cesium, rubidium and thallium, and 0 to 10 parts by weight, calculated as Sb.sub.2 O.sub.3, of an antimony compound, and an inert carrier supporting said catalytically active material thereon, the improvement in which said catalyst is divided into at least two layers, a layer on the gas inlet side and a layer on the gas outlet side, and (i) the content of potassium, cesium, rubidium or thallium is higher in the catalyst layer on the gas inlet side than in the catalyst layer on the gas outlet side, or (ii) the content of the phosphorus compound is lower in the catalyst layer on the gas inlet side than in the catalyst layer on the gas outlet side, or (iii) the surface area of TiO.sub.2 and/or SnO.sub.2 and/or ZrO.sub.2 is lower in the catalyst layer on the gas inlet side than in the catalyst layer on the gas outlet side.

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Himeji, Japan

Ikuo Kurimoto