Isolation of butadiene from a C4-hydrocarbon mixture

摘要

A process for isolating butadiene, with the aid of a selective solvent, from a C4-hydrocarbon mixture which contains butadiene and small amounts of styrene and may contain oxygen, hydrocarbons more soluble than butadiene in the selective solvent and hydrocarbons less soluble than butadiene in the selective solvent, in which process the C4-hydrocarbon mixture is separated by extractive distillation into a distillate which contains the less soluble hydrocarbons, a stream of butadiene and a stream containing the more soluble hydrocarbons, and in which a mixture of styrene and C4-hydrocarbons is removed from the C4-hydrocarbon mixture in a distillation zone upstream of the extractive distillation, the top product of the said distillation zone being fed to the extractive distillation.