MEMBRANE PROCESS FOR TREATING MIXTURE CONTAINING DEWAXED OIL AND DEWAXING SOLVENT

摘要

PURPOSE: To effect separation in excellent selectivity and in a high amount of a permeate by bringing a charge containing a dewaxed oil and a dewaxing solvent into contact with a non-rigid silicone elastomer separation membrane layer treated with e.g. a polyisocyanate. ;CONSTITUTION: A charge containing a dewaxing solvent and a dewaxed oil is brought into contact with and passed through a separation membrane diaphragm containing a non-rigid silicone elastomer separation layer crosslinked or chain-extended with a polyisocyanate, a poly(carbonyl chloride) or a silane of the formula [wherein R is H, an alkyl, an aryl or the like; A is OH, NH₂ or OR' (wherein R' is R) or the like; and a is 2-4]. The pressure drop across the both surfaces of the membrane is maintained to form a low-pressure-side permeated product having an increased content of a dewaxed oil and a decreased content of a dewaxing oil, and the pressure on the low-pressure discharge side of the membrane is maintained at a value higher than the vapor pressure of the permeated product to accumulate the permeated product in the liquid phase. The pressure on the high-pressure retentate side of the membrane is maintained at a value higher than the vapor pressure of the charge to accumulate a mixture of the dewaxing solvent and the dewaxed oil and the retentate as the liquid phase.;COPYRIGHT: (C)1993,JPO