Separation of Sunflower Oil from Hexane by Use of Composite Polymeric Membranes

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

JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY (JAOCS)

SPRINGER

Año: 2011 vol. 88 p. 1813 - 1819

0003-021X

Vegetable oil extraction, as performed today by the oilseed-crushing industry, usually involves solvent extraction with commercial hexane. After this step, the vegetable oil–hexane mixture (miscella) must be treated toseparate its components by distillation. If solvent-resistantmembranes with good permeation properties can be obtained, membrane separation may replace, or be used in combination with, conventional evaporation. Two tailormade flat composite membranes, poly(vinylidene fluoride) (PVDF–Si and PVDF–CA) and a commercially availablecomposite membrane (MPF-50), were used to separate acrude sunflower oil–hexane mixture. The effects of temperature,cross-flow velocity (v), transmembrane pressure (Dp), and feed oil concentration (Cf) on membrane selectivityand permeation flux were determined. The PVDF–Simembrane achieved the best results, being stable in commercial hexane and having promising permselectivityproperties for separation of vegetable oil–hexane miscella.Improved separation performance was obtained at Cf =25%, Dp = 7.8 bar, T = 30 C, and v = 0.8 m s-1; alimiting permeate flux of 12 Lm-2 h-1 and 46.2% oilretention were achieved. Low membrane fouling was observed under all the experimental conditions studied.