Verfahren zur Zerlegung von C?-Kohlenwasserstoffgemischen

摘要

1284233 Separating C 5 -hydrocarbons FAKBENFABRIKEN BAYER AG 19 Aug 1969 [24 Aug 1968] 41351/69 Heading C5E C 5 -Hydrocarbon mixtures comprising cyclic, branched and normal paraffins, olefins and diolefins are separated by the following process sequence: (1) the original mixture is separated by liquid-liquid extraction using a selective solvent into (a) a raffinate comprising paraffins and olefins and (b) a solvent extract comprising diolefins; (2) the solvent extract (b) is subjected to extractive distillation to produce (c) a head product comprising isoprene and cyclopentene (which may be separated by conventional distillation) and (d) a residue comprising selective solvent and residual C 5 -diolefins; (3) the selective solvent is separated from residue (d) by liquid-liquid extraction using a second solvent selective for the diolefins; and (4) the second solvent is separated from the diolefins by conventional distillation; a proportion of the C 5 -hydrocarbon vapours obtained as a head product in step (4) being used to provide heat for extractive distillation step (2). The selective solvent in step (1) is suitably N-methyloxazolidone or 1-oxo-1-methyl phospholine, the latter solvent containing 2% water being used in the example; and the second solvent in step (3) is suitably hexane or heptane. The process is described with the aid of a detailed flow-sheet.