METHOD OF OIL FRACTION SELECTIVE REFINING Russian patent published in 1996 - IPC

FIELD: oil refining. SUBSTANCE: oil fraction is added to middle part of extractor and contacted with solvent which is added to its upper part in the presence of antisolvent. The latter is added to bottom part of extractor followed by solvent regeneration from raffinate and extractive solutions and raffinate and extract were obtained. Raffinate is distilled off and vapor zone is isolated and after cooling the first part of raffinate and liquid phase were obtained. Part of the first fraction is cooled to temperature not exceeding that at raffinate solution outlet from extractor top and added to extractor between raw and antisolvent addition. Remained part of liquid phase is removed as the second raffinate fraction. EFFECT: improved method of oil refining. 9 tbl, 2 dwg