Using FFA and gan three ester in supercritical CO2 dissolved differences in performance, through the extraction temperature and pressure control, to removing the FFA in oils and fats.The commonly used methods are partial pressure extraction, two stage separation and distillation column chromatography.Partial pressure extraction is successively adopt different pressure was carried out on the same batch of oil extraction, oils with different content of FFA.Zhao Weiqi equal pressure extraction of rice bran oil, palm oil planttwo pieces found FFA focused primarily on 15 mpa pressure component extraction, and during the next 35 mpa pressure FFA content in the extracted oil is low.Zhang with two separate kettle, such as separation of FFA in the wheat germ oil, acid value of 7189), by adjusting the two separate reactor pressure and temperature, in the first level of isolated oil acid value decreased to 110, the first secondary oil acid value increased to 4917, the acid effect is obvious.Using extraction kettle in combination with two separate kettle to separation, Chinese prickly ash seed oil with high acid value found in the extraction kettle 30 mpa pressure, temperature 40 ℃, the separation of reactor pressure 13 mpa, temperature 35 ℃ separation reactor pressure of 5 mpa, the temperature of 40 ℃, bucket elevatorthe separated oil acid value in the extraction kettle fell to 415, separate kettle Ⅰ ceding oleic acid value is 10216, separate kettle Ⅱ divided oleic acid value as high as 21013.Bondioli using tertiary distillation column to reduce levels of FFA in the olive oil, found under the pressure of 13 mpa, 50 ℃ and 40 ℃ / 30 ℃ temperature gradient.The yield of refined oil (8918%), high low acid value (018).You can see from the above experiment: FFA in low density SC2CO2 solubility than glyceride.Therefore, should be increased by reducing the pressure or temperature to change SC2CO2 density, to achieve effective separation of fatty acids.
8, membrane separation, acid...