Patent ID: 7211698
Filing Date: 2007-05-01
Classification: C07C

Abstract:
1. A process for distillatively working up an aqueous composition which comprises 1,1,2,2-tetramethoxyethane, glyoxal dimethyl acetal and methanol, wherein the composition is worked up to form at least one low boiler fraction, at least one medium boiler fraction and at least one high boiler fraction in a dividing wall column in which a dividing wall is arranged in the longitudinal direction of the column to form an upper common column region, a lower common column region, a feed section having rectifying section and stripping section and a withdrawal section having rectifying section and stripping section, the dividing wall is arranged between the upper and the lower common column region and the aqueous composition is fed to the middle region of the feed section, and at least one medium boiler fraction comprising aqueous 1,1,2,2-tetramethoxyathane is obtained as a sidestream from the middle region of the withdrawal section, at least one high boiler fraction comprising glyoxal dimethyl acetal from the lower common column region and at least one low boiler fraction comprising methanol from the upper common column region.