Mitsubishi Chemical Corporation

Kazuharu Tazawa

Isao Teshigahara

Takanori Taniguchi

Takuya Nakamura

Nariyasu Kanuka

Teruo Saito

Yoshimune Abe

Mitsunobu Ito

Atsuhisa Maeda

A ring-shaped catalyst may have a straight body part and a hollow body part, which is used when a gas-phase catalytic oxidation reaction of a material substance is conducted to produce a target substance, wherein a length of the straight body part is shorter than a length of the hollow body part and at least at one end part, a region from an end part of the straight body part to an end part of the hollow body part is concavely curved.

Catalyst and catalyst group

An object of the present invention is to provide a catalyst ensuring that when a gas-phase catalytic oxidation reaction of a material substance is conducted using a catalyst to produce a target substance, the pressure loss and coking are suppressed and the target substance can be produced in high yield. The present invention is related to a ring-shaped catalyst having a straight body part and a hollow body part, which is used when a gas-phase catalytic oxidation reaction of a material substance is conducted to produce a target substance, wherein a length of the straight body part is shorter than a length of the hollow body part and at least at one end part, a region from an end part of the straight body part to an end part of the hollow body part is concavely curved.

An object of the present invention is to provide a catalyst ensuring that in the case of causing gas-phase catalytic oxidation of an unsaturated aldehyde and an oxygen-containing gas with use of the catalyst to produce a corresponding unsaturated carboxylic acid, the pressure loss can be kept low and an unsaturated carboxylic acid can be produced with high selectivity. The present invention relates to a ring-shaped or columnar catalyst, which is used at the time of producing a corresponding unsaturated carboxylic acid by causing gas-phase catalytic oxidation of an unsaturated aldehyde and an oxygen-containing gas, wherein the outer peripheral edge part is inclined relative to the center line.

Catalyst, acrylic acid production method, and catalyst production method

A process for producing a catalyst which has a high mechanical strength and is capable of producing an unsaturated aldehyde and an unsaturated carboxylic acid constantly over a long period of time and in good yield; and, a method for producing an unsaturated aldehyde or carboxylic acid from catalytic oxidation of an olefin, a tertiary butyl alcohol, or a methyl tertiary butyl ether substrate with a gas that contains molecular oxygen and the produced catalyst.

Process for producing catalyst for production of unsaturated aldehyde and unsaturated carboxylic acid

A method for compression molding a cylindrical tablet is presented, the method being capable of preventing the occurrence of cracks and the breakage of core punches. The method for compression molding a cylindrical tablet is achieved by using a rotary powder compression molding machine provided with a die and upper and lower punches fitted to a rotary table and a core punch penetrating the punch end of a lower punch. The compression molding method being characterized by using the core punch in which the difference between the smallest diameter of the core punch at the protion for forming the center opening of the cylindrical tablet and the reference diameter of the portion in design is within 0.04 mm.

Method for compression-molding a cylindrical tablet

A method for packing a solid catalyst is provided, whereby the pressure loss of a reaction tube packed with the catalyst can be reduced. The method is characterized in that prior to packing a solid catalyst in a reactor, the solid catalyst is sieved to remove a cracked catalyst. For example, sieving is carried out against a solid catalyst of a columnar or cylindrical shape having an outer diameter A being larger than the length B in the axial direction by using a sieve having a sieve mesh with a width C satisfying the condition of A&#x3e;C&#x3e;B and a length being at least the width, or against a solid catalyst of a columnar or cylindrical shape with an outer diameter A being from 1 to 0.5 time the length B in the axial direction by using a sieve having a sieve mesh with a width C satisfying the condition of A&#x3e;C&#x3e;0.5B and a length being at least the width.

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Tokyo, Japan

Kazuharu Tazawa