METHOD OF OILY FRACTION SELECTIVE REFINING Russian patent published in 1998 - IPC

FIELD: chemical technology. SUBSTANCE: method involves countercurrent contact of raw feeding to middle part of extractor with solvent adding to upper part of extractor in the presence of antisolvent feeding to bottom part of extractor followed by solvent regeneration from rafinate and extractive solutions and rafinate and extract producing. Part of rafinate solution removing from upper zone of extractor is recovered to bottom zone of extractor (but not above zone of raw addition) at temperature not exceeding of that of raw feeding and not lower of that of antisolvent feeding. Part of extract is recovered in extractor between addition of solvent and rafinate solution at temperature not exceeding of that solvent feeding and not lower of that antisolvent feeding. EFFECT: increased rafinate yield in process of liquid extraction. 2 dwg, 9 tbl