FIELD: chemistry.
SUBSTANCE: method involves: a) heterogeneously catalysed vapour-phase partial oxidation of a starting organic compound selected from propylene, propane, isobutylene, isobutane, acrolein or methacrolein with molecular oxygen in a parallel-functioning system of oxidation reactors containing catalysts, which results in formation of two gas streams respectively containing the desired compound and respectively formed in one of two systems of oxidation reactors, and b) subsequent extraction of the desired product from two streams of the obtained gas to form at least one stream of crude desired product according to which c) before extraction of two from two streams, the obtained gas is mixed with each other into a mixed stream. In case of change in selectivity of formation of the desired product and/or by-products during operation the entire amount or partial amount of catalyst is replaced in parallel with fresh catalyst not in all parallel-functioning systems of oxidation reactors in which end products contained in the mixed stream are formed.
EFFECT: improved method of obtaining acrolein, acrylic acid, methacrolein or methacrylic acid as the desired product.
2 cl, 4 tbl, 2 ex
