Nippon Kayaku Kabushiki Kaisha

Shogo Yasuda

Ryota Hiraoka

Tomoyuki Kawamura

Takanori Nakano

Provided is a method for producing an unsaturated aldehyde including subjecting an alkene to partial oxidation using a fixed bed multi-tube reactor to produce the corresponding unsaturated aldehyde, in which n catalyst layers (n is 2 or more) in a gas flow direction in a reaction tube are provided, when a filling length of the catalyst layers from a first catalyst layer to an (n−1)th catalyst layer from a gas inlet side of the reaction tube is L, and a filling length of an nth catalyst layer from the gas inlet side of the reaction tube is Ln, a relationship between L and Ln satisfies the following equation (1): and

Method for producing unsaturated aldehyde

Provided is a method for producing at least one of an unsaturated aldehyde and an unsaturated carboxylic acid from an alkene by an oxidation reaction, in which a n-layered catalyst layer (n&#x2265;2) is provided in a gas flow direction in a reaction tube, two or more kinds of catalysts having different activities are used; and the catalysts are packed in such a manner that dT&#x2264;20&#xb0; C. is satisfied, when a difference between a temperature PTof an exothermic peak in a n-th layer as counted from a gas inlet and a minimum value mTof a temperature of a catalyst layer which appears between an exothermic peak in a (n-1)th layer and an exothermic peak in a n-th layer from the gas inlet is represented as dT (=PT&#x2212;mT), and the change rate of dT is 2.5 or less at a reaction bath temperature within a range of &#xb1;6&#xb0; C. of a reaction bath temperature at which the highest yield is obtained.

Method for producing at least one of unsaturated aldehyde and unsaturated carboxylic acid and catalyst for producing at least one of unsaturated aldehyde and unsaturated carboxylic acid

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Yamaguchi, Japan

Shogo Yasuda