PROCESS FOR REMOVAL OF ACRYLIC ACID FROM THE PRODUCT GAS MIXTURE OF A HETEROGENEOUSLY CATALYZED PARTIAL GAS PHASE OXIDATION OF AT LEAST ONE C3 PRECURSOR COMPOUND

摘要

A process for removal of a crude acrylic acid from a product gas mixture which comprises glyoxal as a by-product from a heterogeneously catalyzed partial gas phase oxidation of at least one C₃ precursor compound, which comprises the absorption of the acrylic acid in a high-boiling absorbent and the rectificative workup of the resulting adsorbate, and in which absorbent present in the bottoms liquid withdrawn from the bottom space of the absorption column is distilled off in a distillation unit and recycled into the absorption, before high boilers which remain are discharged, and in which the glyoxal content of the crude acrylic acid is reduced by restricting the high boiler residence time in the distillation unit.