Patent ID: 7226527
Filing Date: 2007-06-05
Classification: B01D,C07C,Y10S

Abstract:
1. A process for recovering crude 1,3-butadiene from a C 4 fraction by extractive distillation using a selective solvent, which is carried out in a dividing wall column in which a dividing wall is arranged in the longitudinal direction of the column to form a first subregion, a second subregion and a lower common column region and which is preceded by an extractive scrubbing column, wherein the C a stream taken off at the top from the first subregion of the dividing wall column is fed to the extractive scrubbing column in its upper region, a countercurrent extraction is carried out in the extractive scrubbing column by treatment with a first substream of the selective solvent in the upper region of the extractive scrubbing column, the components of the C a bottom stream from the extractive scrubbing column is recirculated to the upper region of the first subregion of the dividing wall column, a second substream of the selective solvent is fed to the dividing wall column in the middle region of the second subregion, selective solvent laden with 1,3-butadiene together with components of the C the product is taken off at the top from the second subregion of the dividing wall column as crude 1,3-butadiene.