Extracting oils and fats - from exhausted adsorbent with supercritical carbon di:oxide

摘要

In extn. of oils and fats, esp. of paraffinic and glycidic oils and fats from exhausted adsorbents, e.g. fuller's earth, C and/or SiO2 gel, the fats and/or oils are extracted with supercritical CO2. Extn. is carried out at 31-100 (35-75) deg. C and/or the sepn. temp. is 0-100 deg. C; the pressure is 200-750 (300-500) bars and/or the sepn. pressure is 32-120 bars. Addtional extractants, e.g. NO and/or ethane and/or propane, may be used. The extracted fats and/or oils are sepd. from the CO2, eg. by pressure release, and the CO2 is re-used, pref. in a closed cycle, for extn. of fuller's earth. ADVANTAGE - Good quality oils and fats, suitable for food, are released, and the adsorbents can be re-used. Ext. is controlled so that only neutral fats are extracted, leaving free fatty acids and other polar substances in the fuller's earth.