PROCESS FOR CONVERTING HYDROPHILIC,WATER CONTAINING REGENERATED CELLULOSE MEMBRANES TO MEMBRANES USEFUL FOR SEPARATING ORGANIC LIQUIDS

摘要

A hydrophilic, water-containing regenerated cellulose membrane is sequentially permeated under differential pressure with solvents of decreasing polarity so as initially to displace water in the membrane with a first solvent, and the or each other solvent in the sequence displacing the previous solvent. Each solvent has bulk liquid-liquid miscibility with the adjacent solvent(s) in the sequence, and the final solvents of the sequence exhibits bulk liquid-liquid miscibility with a material ultimately desired to be selectively permeated through the membrane. The first solvent is a lower (C1-C4) alcohol or acetone. The resulting membrane is practically suitable for at least partially separating, by permeation, a solvent used in dewaxing a waxy hydrocarbon oil from a solution of the oil and solvent.