METHOD AND DEVICE FOR THE TWO-STEP PRODUCTION OF ACRYLIC ACID

摘要

alpha,beta-ethylenically unsaturated aldehydes and/or carboxylic acids are prepared by means of a two-stage catalytic gas-phase oxidation in which a gas mixture comprising at least an alkane or alkene having from three to six carbon atoms and oxygen is subjected to a catalytic oxidation reaction, in the first stage ( 1 ). Oxygen is added to the gases produced in the first stage ( 1 ) and the resulting mixture is introduced into the second stage ( 2 ) in which it is subjected to a further catalytic oxidation reaction. In the process of the present invention, a signal which correlates with the oxygen content of the reaction gases before and/or after the addition of oxygen between the first and second stages ( 1, 2 ) is generated and the oxygen addition is regulated as a function of the signal. Also provided are an apparatus for regulating a process for preparing alpha,beta-ethylenically unsaturated aldehydes and/or carboxylic acids and an apparatus for preparing these substances using the regulating apparatus of the present invention.