Sunflower Oil/Hexane Separation by Composite Polymeric Membranes

C. PAGLIERO; N. A. OCHOA; P. MARTINO ; J. MARCHESE

JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY (JAOCS)

SPRINGER

Lugar: Berlin; Año: 2011 vol. 88 p. 1813 - 1819

0003-021X

Abstract. Vegetable oil extraction, as performed today by the oilseed crushing industry, usually involves a solvent extraction step with commercial hexane. After this step, the vegetable oil/hexane mixture (miscella) must be treated to separate its components by distillation. Membrane separation technology may be a better option provided that solvent resistant membranes with good permeation properties can be obtained to replace or combine with conventional evaporation technology. Two tailor-made flat composite membranes poly(vinylideneflouride) (PVDF) and a commercially available composite membrane (MPF-50) were used to separate a crude sunflower oil-hexane mixture. The effects of temperature, cross flow velocity (v), transmembrane pressure (Äp) and feed oil concentration (Cf) on membrane selectivity and permeation flux were determined. The PVDF-SI membrane achieved the best results being stable in commercial hexane and having promising permselectivity properties to separate vegetable oil/hexane miscella. Improved separation performance was obtained at Cf=25%, Äp=7.8 bar, T=30°C, and v=0.8 m/s, achieving a limiting permeate flux of 12 Lm-2h-1 and 46.2% oil retention. Low membrane fouling was observed in all experimental conditions studied.