| 摘要 |
The present invention concerns a method for producing acrolein and acrylic acid by carrying out vapor phase catalytic oxidation of propylene with molecular oxygen or a gas containing molecular oxygen using a oxidation catalysts comprising Mo, Bi and Fe as an essentially element and a fixed bed multitubular reactor, which comprises a) using a plurality of supported catalysts having different activities, which was obrtained, for example, by different calcination method in the production process of the supported catalysts, b) setting a catalyst layer in a reaction tube, which is formed by dividing it into plural portions in the tube axial direction, and c) arranging the aforementioned plural supported catalysts in such order that the activity becomes high toward the outlet from the inlet of the material gas in the reaction tube axial direction. According to the present invention, the generation of hot spot can be avoided and over oxidation reaction can be avoided and the acrolein and acrylic acid are produced constantly for a prolonged period of time. |
