PREPARATION OF ACROLEIN OR METHACROLEIN BY ACTALYTIC GAS-PHASE OXIDATION OF PROPENE OR ISOBUTENE

摘要

A process for the catalytic gas-phase oxidation of propene or isobutene to acrolein or methacrolein in a tubular fixed bed reactor or catalytically active oxides with a >/=90% conversion of the initial olefin on a single passage, wherein the temperature of the gases containing the reactants in the direction of flow along the tubes from their entrance until the conversion of the initial olefin is from 30 to 70% is from 360 DEG to 420 DEG C. and is then adjusted to from 360 DEG to 300 DEG C. until the conversion of the initial olefin is from 80 to 90% and is thereafter maintained at from 330 DEG to 390 DEG C. until the gases emerge from the tubes, is described.