| 摘要 |
1437470 Separation of vinyl aromatics from mixtures by extractive distillation SNAMPROGETTI SpA 23 Nov 1973 [29 Nov 1972] 54626/73 Heading C5E Vinyl aromatic hydrocarbons are separated from hydrocarbon mixtures comprising other aromatic hydrocarbons by extractive distillation using a solvent mixture comprising 1-30% by weight of water, and one or more polar solvents boiling above 150‹ C. and selected from aldomorpholines (e.g. N-formyl morpholine), ketomorpholines, sulpholane N-methyl pyrrolidone. A feed 1, e.g. a C 8 or C 6-8 cut produced from the steam cracking of naphtha, is extractively distilled at 9 using a solvent mixture 2 to produce an overhead 3, which is separated into a water stream 17 and a hydrocarbon stream 16, and an extract 4 comprising styrene, o-xylene and solvent mixture. The extract 4 is extractively distilled in a second column 10 to provide an overhead 6 which is enriched in oxylene and which is recycled to the column 9 and a bottoms 7. the bottoms 7 is stripped at 12 to provide a solvent stream 14 and an overhead which is separated into a styrene product 8, e.g. containing 99À8% styrene and an aqueous stream 18. |
