| 摘要 |
1405077 Extractive distillation METALLGESELLSCHAFT AG 22 Feb 1973 [22 Feb 1972] 8856/73 Heading BIB [Also in Division C5] In the extractive distillation of a feed 18 in a plate column 13 the solvent-extract mixture is withdrawn from the lowermost plate 4 of the column and heated by indirect heat exchange at 1 with hot liquid regenerated solvent 14 which has been separated from the solvent in a separate solvent stripping column 16 and the heated solvent-extract mixture is subsequently fed to the reboiler 12 of the extractive distillation column. In Examples 1 and 2 benzene is separated from thermally cracked gasoline using N methylpyrrolidone as the extractive solvent. In Example 3 a mixture comprising benzene, toluene, xylene, non- aromatic hydrocarbons and butyrolactone and which has been obtained in a liquid-liquid extraction process is extractively distilled to provide an overhead comprising the benzene and non-aromatic components, which is recycled to the liquid-liquid extraction, and a toluene-xylene-butyrolactone extract, which is separated in a solvent stripping column, |
