| 摘要 |
In the separation of a mixture of hydrocarbons, in which the less soluble materials (raffinate) are more volatile than water, e.g. the separation of aromatics from non-aromatics, by solvent extraction with a water-miscible solvent boiling higher than the hydrocarbons, the raffinate is washed with an aqueous medium at least a portion of which is thereafter introduced into the fractionating solumn in which any less-soluble materials are removed from the extract prior to stripping the aromatics, such less-soluble materials preferably being returned as reflux to the extraction. In a modification, the water is at least partially freed by stripping of less readily soluble hydrocarbons and is then introduced, preferably in the vapour phase, into the solvent stripper. A combination of the two embodiments may be used. The use of sulpholane and glycol type solvents is referred to for separating aromatics from reformates, cracked gasolines and coal products. Specifications 625,505, 659,241 and 764,650 are referred to. |
