METHOD OF LIQUID EXTRACTION Russian patent published in 1998 - IPC

FIELD: liquid extraction in petroleum processing and chemistry. SUBSTANCE: process includes introducing initial component mixture between raffinate and extract sections of extractor, supplying basic solvent into extractor to create therein flow of extract solution and "washing off" solvent or antisolvent to excite flow of raffinate solution, and withdrawing final extract, basic, and intermediate raffinate solutions from extractor followed by recovery of solvents therefrom to form extract and two raffinates. Raffinate solution stream is divided into two portions in intermediate cross-section of extract section to form two zones where raffinate and extract solutions come into countercurrent contact with each other. One portion of raffinate solution and extract solution are in contact in the zone adjacent to initial mixture-into-extractor introduction site. In the other zone, remaining part of raffinate solution is brought in contact with extract solution formed by way of introducing additional amount of solvent into extractor in the cross-section where intermediate raffinate solution is withdrawn. EFFECT: enhanced process efficiency. 2 dwg, 2 tbl