Sunflower oil miscella degumming with polyethersulfone membranes: Effect of process conditions and MWCO on fluxes and rejections

The aim of this work was to study the removal of phospholipids from sunflower oil miscella by membrane filtration using a cross-flow UF pilot-plant. Two tubular polyethersulfone membranes with different MWCO (4000 and 9000 Da) were compared. A sunflower oil miscella with an oil content of about 30% w/w was used as feed and the following operating conditions were employed: 40 °C, 5 m/s, and 0.4–1.2 MPa. Both membranes presented approximately the same rejection of phospholipids (95–97%), although the 9000 Da membrane showed higher miscella permeate flux, lower oil rejection and higher free fatty acids rejection. The influence of operating parameters, i.e. temperature, feed flow rate, and applied pressure, on fluxes and rejections was studied with the 9000 Da membrane. The results were then evaluated in order to choose the best operating conditions to concentrate a sunflower oil miscella using this membrane up to a VCR of 3.2.