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 75 to 98 per cent by weight of an N-alkylsubstituted lower aliphatic acid amide or of an N-alkylsubstituted alicyclic acid amide having 5 ring members, boiling at from 140 to 260.degree.C, or butyrolactone or methoxypropionitrile and b) from 2 to 25 per cent by weight of acetonitrile.