Butadiene recovery - from hydrocarbon mixtures by extractive distillation

摘要

Recovery of butadiene from mixts. of this with other C4 hydrocarbons by subjecting the mixt. to extractive distillation with a polar solvent (esp. acetonitrile contg. ca. 10% water), passing the solvent (opt. after partial discharge of dissolved material) to a first stripping zone working at a lower pressure than the extractive distillation zone, to give a butadiene-enriched vapour steam, compressing this stream and recycling part of it to the extractive distillation zone and passing the remainder to a second stripping zone from which substantially pure butadiene is obtd.