Degumming of crude soybean oil by ultrafiltration using polymeric membranes

In this study, the ability of two ultrafiltration polymeric membranes to pe rform the degumming of a crude soybean oil/hexane mixture is tested. The pe rformance of both membranes is defined in terms of their permeation flux, p ermeate color, and rejection of phospholipids. One of the membranes was syn thesized in our laboratories from polyvinylidenefluoride (PVDF); the other one is a commercially available membrane made of polyimide. The degumming e xperiments were done in a stirred dead-end ultrafiltration cell pressurized with N-2. Results show that tested membranes are suitable for removing pho spholipids from the crude oil/hexane miscella in the range of temperature a nd transmembrane pressure utilized in this work. Both membranes have high s electivity regarding phospholipids and produce a moderate reduction in perm eate color. The PVDF membrane gives permeate fluxes up to threefold larger than those obtained with polyimide membrane at the same operational conditi ons, making the former more suitable for use at industrial scale.