In this work, the separation of refined soybean oil/n-hexane mixtures was investigated using a commercial hollow fiber ultrafiltration membrane 50 kDa. Three alcohols with different chain lengths were tested for the conditioning of the membrane; n-propyl alcohol showed the highest n-hexane permeate flux after conditioning. There was a decrease in the rejection and an increase in permeate flux over time. This behavior may be related to swelling and membrane plasticization by the oil. Rejections from 10.0 to 28.7% and total permeate fluxes from 12.2 to 65.3 kg/m²h were observed. An increase in the oil/n-hexane mass ratio and the pressure caused an increase in the rejection and permeate total flux for most assays. No degradation was observed in the membrane module.
Soybean oil; n-Hexane; Solvent recovery; Hollow fiber; Ultrafiltration; Membrane conditioning