PROCESS FOR PRODUCING(METH)ACROLEIN AND/OR(METH)ACRYLIC ACID

摘要

A process for producing (meth)acrolein and/or (meth)acrylic acid in high yield by the catalytic vapor−phase oxidation of either of isobutylene or the like and propylene with molecular oxygen in a fixed−bed tubular reactor in the presence of a solid oxidation catalyst, wherein the temperature in the hot spot region is sufficiently controlled. The process comprises passing oxygen and a feed gas comprising either of isobutylene or the like and propylene through a layer of a solid oxidation catalyst packed in a fixed−bed tubular reactor, and is characterized in that before the feed gas passing, oxygen and a gas containing either of isobutylene or the like and propylene in a lower concentration than that in the feed gas are passed for 1 hour or longer.