PROCESS FOR THE PREPARATION OF ACROLEIN AND ACRYLIC ACID.

摘要

A process for the preparation of acrolein and acrylic acid by catalytic vapor-phase oxidation of propylene with molecular oxygen or a gas containing molecular oxygen in the presence of an oxidation catalyst containing Mo, Bi and Fe as the essential components in a fixed-bed multi-tubular reactor, characterized by a) using two or more supported catalysts different from each other in activity and prepared by modifying the firing operation employed in the production of the catalyst, b) dividing the tubular reactor in the axial direction to form two or more catalyst zones, and c) arranging the supported catalysts in such an order that the activity increases in the axial direction of the tubular reactor from the inlet side of the feedstock gas toward the outlet side thereof. According to the process, the occurrence of a hot spot can be avoided and acrolein and acrylic acid can be prepared stably over a long time.