| abstract |
PROBLEM TO BE SOLVED: To provide a method for producing acrolein and acrylic acid by vapor-phase oxidation of propylene in the presence of a molybdenum-bismuth-iron-based composite oxide catalyst, wherein sublimation of a molybdenum component is suppressed, Acrolein and acrylic acid in a stable and high yield over a long period of time. SOLUTION: The Fe / (Co + Ni) ratio is kept constant, Using a plurality of types of molybdenum-bismuth-iron-based composite oxide catalysts in which the amounts of Co and Ni are changed, the above-mentioned plurality of types of composite oxides are moved from the raw material gas inlet side to the outlet side of the fixed bed reactor. By filling the catalyst such that the amount ratio of Co / (Co + Ni) becomes small, the inside of the reactor is divided into two or more reaction zones, and an oxidation reaction of propylene is performed. |