Vegetable Oil Degumming with Polyimide and Polyvinylidenfluoride Ultrafiltration Membranes

C. PAGLIERO; N.A. OCHOA; J. MARCHESE; M. MATTEA

JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY

Wiley & Sons

Lugar: Londres; Año: 2004 vol. 79 p. 148 - 152

0268-2575

The removal of phospholipids ('degumming') is the first step in the process of refining crudevegetable oü. Membrane separation has been often proposed as an alternative to the conventionalprocedure (water degumming). Until now, the instability of polymeric membranes in organic solvents hasbeen the major obstacle in applying this technique. In this work, a local synthesized polyvinylidenefluoride(PVDF) and a commercial polyimide (PI) membrane were evaluated for their flux and rejection propertiesduring degumming of soybean oil in a laboratory-scale cross-flow ultrafiltration cell. Degummingexperiments were done at different temperatures and feed flows, keeping constant both the feedconcentration and the transmembrane pressure. PVDF and PI membranes gave selectivity values andpermeate color that did not differ significantly from each other. Retention coefficients larger than 98%were obtained in al1 cases. In every experiment, a decline in permeate flux with time occurred at thebeginning of the degumming process. By increasing the feed rate, a higher permeate flux was obtained.The results show that the PVDF membrane had a higher productivity than the PI one