ISOLATION OF A CONJUGATED DIOLEFIN FROM A C.SUB.4- OR C.SUB.5- HYDROCARBON MIXTURE

摘要

A process for isolating a conjugated diolefin from a C4- or C5-hydrocarbon mixture containing the diolefin, by single-stage or multi-stage extractive distillation using a selective solvent, wherein the selective solvent is a solvent mixture which comprises: a) from 50 to 98 percent by weight of an N-alkyl-substituted lower aliphatic acid amide or of an N-alkyl-substituted alicyclic acid amide having 5 ring members and b) from 2 to 50 percent by weight of a lower aliphatic carboxylic acid ester or carbonic acid ester boiling at from 30.degree.C to 200.degree.C.