Extraction of Rice Bran Oil Using Supercritical Carbon Dioxide and Propane

摘要

Extraction of rice bran lipids was performed using supercritical carbon dioxide(SC-CO_2)and liquid propane.To provide a basis for extraction efficiency,accelerated solvent extraction with hexane was performed at 100 deg C and 10.34 MPa.Extraction pressure was varied for propane and SC-CO_2 extractions.Also,the role of temperature in SC-CO_2 extraction efficiency was investigated at 45,65,and 85 deg C.For the SC-CO_2 experiments,extraction efficiencies were proportional to pressure and inversely proportional to temperature,and the maximal yield of oil achieved using SC-CO_2 was 0.222 +-0.013 kg of oil extracted per kg of rice bran for conditions of 45 deg C and 35 MPa.The maximal yield achieved with propane was 0.224 +-0.016 kg of oil per kg of rice bran at 0.76 MPa and ambient temperature.The maximum extraction efficiencies of both SC-CO_2 and propane were found to be significantly different from the hexane extraction baseline yield,which was 0.261 +-0.005 kg oil extracted per kg of rice bran.A simulated economic analysis was performed on the possibility of using SC-CO_2 and propane extraction technologies to remove oil from rice bran generated in Mississippi.Although the economic analysis was based on the maximal extraction efficiency for each technology,neither process resulted in a positive rate of return on investment.