REACTION TUBE, PROCESS FOR PRODUCING CATALYST AND PROCESS FOR PRODUCING UNSATURATED ALDEHYDE AND UNSATURATED CARBOXYLIC ACID

摘要

In a gas phase catalytic oxidation method for producing an unsaturated aldehyde and an unsaturated carboxylic acid which comprises packing a catalyst containing an additive into a reaction tube and heating a gas passing through the reaction tube while maintaining the temperature at the outlet higher than the temperature at the inlet of the catalyst precursor layer of the gas, a catalyst with excellent performance which little suffers from lowering in catalytic performance caused by the thermal decomposition of the additive, etc. in the step of heating the catalyst can be conveniently produced at a high reproducibility.