Bench-scale membrane degumming of crude vegetable oil: Process optimization

Crude vegetable oils contain various minor substances such as phospholipids, coloring pigments, and free fatty acids (FFA) that may affect the quality of the finished oil. Reduction of energy costs and waste disposal are major concerns for many oil refiners who are looking for alternative methods to improve conventional refining methods, and during the last decade, energy-efficient membrane separation technology has evolved dramatically. This paper reports the cross-flow bench-scale crude vegetable oil membrane degumming test results using newly available, modified, hexane-resistant, high flux, and high selectivity non-aqueous membranes. Two membranes (DS-7 and AN03) were evaluated for their flux and rejection properties. Process parameters including pressure, temperature, feed velocity and volumetric concentration factor were examined. A 99.6% rejection of phospholipids and a flux of 26.8 1/m(2) h were achieved at pressure 300 psi, temperature 40 degrees C, and feed velocity 220 1/h using DS-7 membrane, and significant reduction of coloring pigments was observed as well. Membrane fouling presented no big problem.