VERFAHREN ZUR GEWINNUNG VON 1,3-BUTADIEN.

摘要

Recovery of 1,3-butadiene (I) from a C4 hydrocarbon stream contg. (I) and small amts. of propyne and C5 hydrocarbons is effected by (a) subjecting the feed to extractive distn. with a selective solvent to obtain a crude butadiene stream, (b) feeding the crude butadiene vapour into a 1st distn. column, (c) passing an overhead liq. stream contg. (I) and lighter impurities from the 1st column to the middle of a 2nd column, (d) passing a liq. side stream contg. (I) and heavier impurities from the stripper section of the 1st column to the bottom of the 2nd column, (e) withdrawing a heavy impurity bottoms stream from the 1st column, (f) withdrawing a light impurity overhead stream from the 2nd column, (g) withdrawing (I) from the stripper section of the 2nd column, and (h) recycling the bottoms stream from the 2nd column to the 1st column in the vicinity of the side stream outlet.