Reversed micellar-enhanced ultrafiltration removal of oil from concentrated phospholipids

Abstract

The de-oiling of concentrated phospholipids through ultrafiltration (UF) enhanced by reversed micelles using a polyethersulfone (PES) membrane was examined. Phospholipids could form reversed micellar structures with larger molecular weights in non-polar solvents, which were significantly different from oils and solvents with smaller molecular weights confirming the feasibility of membrane separation. Under the conditions of membrane retentate molecular weight of 50 kDa, transmembrane pressure difference of 0.30 MPa, inlet crossflow velocity of 2.78 × 10−4 m·s−1, temperature of 333.15 K, phospholipid feed concentration of 26.12 kg·m−3% and cycle ratio of 20:1, the retentate phospholipid content and phospholipid yield were 84.97% and 96.4%, respectively, and the permeate flux was 4.65 × 10−6 m·s−1. Phospholipids increased the hydrophobicity of the membrane surface and promoted concentrated phospholipid de-oiling. Finally, a mathematical model was established based on the two-dimensional concentration polarization mechanism indicating that permeate flux was mainly controlled by the convective transfer flow rate.