Solvent Recovery from Canola Oil/Hexane Miscella Using Nanofiltration Membrane Process

High energy consumption during the recovery of solvent from oils miscella in traditional method, the experts urged is to find new ways to reduce energy consumption in oil extraction industry. Therefore in this study, the nanofiltration (NF) membrane potential to recycle of the hexane solvent from oil/hexane miscella of canola has been studied. In this work, the effect of transmembrane pressure (1.5, 2.0 and 2.5 MPa at three levels) and temperature (20, 30 and 40°C at three levels) on the efficiency of NF process was investigated. The polyamide tubular AFC40 membrane manufactured by PCI membrane systems in a pilot plant system was used in study. Results of temperature and pressure effects on the flux of pure hexane showed that hexane flux increases with increasing operating temperature and pressure. The advantages of using this type of membrane was the stability of the polyamide membrane against solvent and the results of flux profiles versus time showed little change over time in hexane flux is found. According to the type and membrane pore size used in this study were showed that only hexane able to pass through the pores of the membrane and entered in the permeate stream and other compounds found in miscella (including free fatty acids and triglycerides) as retentate back into the feed tank. The results mean the canola miscella flux was increases with increasing temperature and pressure. Because the select the appropriate type and pores size of membrane, fouling of the membrane removed with several times circulation with pure solvent through a membrane and the membrane can be re-used. According to the results, can be propose 30°C and 2.5 Mpa, as the best temperature and pressure for NF process of canola oil/hexane miscella in oil extraction industry.