DEACIDIFICATION OF SOYBEAN OIL BY MEMBRANE TECHNOLOGY

After extracting free fatty acids (FFA) from a model crude vegetable o il with methanol, FFA were separated from methanol by nanofiltration. Of the several commercially available membranes that were evaluated, t he best resulted in FFA rejection of >90% and flux of >25 Lm(-2) h(-1) . A combination of high-rejection and low-rejection membranes resulted in a retentate stream of 35% FFA and a permeate stream with less than 0.04% FFA, which can be recycled to the extractor. No alkali is requi red, no soapstock is formed, and almost all streams within the membran e process are recycled with little discharged as effluent.