Separation of soybean oil/n-hexane and soybean oil/n-butane mixtures using ceramic membranes

This study aimed to investigate the separations of mixtures of refined soybean oil/n-hexane, crude soybean oil/n-hexane (industrial miscella) and refined soybean oil/pressurized n-butane using membrane technology. Commercial ceramic membranes with molecular weight cut-offs between 5 and 10 kDa were employed, varying the mass ratios of the oil/solvent, from 1:1 to 1:3 (w/w). Oil rejections up to 100%, total permeate fluxes (oil + solvent) up to 42.97 kg/m(2)h with oil permeate fluxes up to 1.4 kg/m(2)h were obtained. The industrial miscella showed the same behavior observed for the synthetic mixtures presenting an increase in the oil rejection with a decrease in total permeate flux. In the separation of the oil/n-butane mixtures, higher oil rejections were obtained when compared to the system oil/n-hexane. The results presented in this work indicate the potential applicability of membrane technology in vegetable oil processing and biodiesel industries in the solvent recovery step. (C) 2014 Elsevier Ltd. All rights reserved.