METHOD FOR PRODUCING UNSATURATED ALDEHYDE

摘要

PROBLEM TO BE SOLVED: To provide a method for producing an unsaturated aldehyde by which a reaction can be continued over a long period while maintaining high yield irrespective of where hot spot parts are formed and even if the raw material gas concentration is high when an unsaturated aldehyde and/or an unsaturated carboxylic acid are produced by the gas-phase catalytic oxidation reaction using a fixed-bed multitubular reactor filled with a molybdenum catalyst. SOLUTION: The method for producing the unsaturated aldehyde comprises using a granular catalyst which is an oxide or a compound oxide consisting essentially of molybdenum, bismuth and iron and having an outside diameter D1 comprising a hole part with an opening having an inside diameter D2 as the catalyst. The interior of each reaction tube in the fixed-bed multitubular reactor is divided in the tubular axis direction to provide a plurality of reaction zones and the catalyst having the different D2 is filled in at least two of the reaction zones. COPYRIGHT: (C)2004,JPO