| Vegetable oil deacidification is an important step in oil processing. This has led to research in various methods for carrying out the process. An alternative method that combines supercritical carbon dioxide and synthetic membranes (nanofiltration) is investigated in this work.; A specialized, high pressure, membrane cell was designed, fabricated, and then coupled to two ISCO SFE systems. The cell consisted of three major components. The first was a base with internal threaded walls and a grooved bottom that serves as an outlet for permeate and a support surface for a porous metal disc to support the membrane. The second part was a cell body with threaded connections into the base, and the third part was a threaded top cap connected to the cell body; it also held an inlet hex-nut assembly. The cell capacity was 67 mL. A SFE syringe pump provided the pressure on the feed side of the membrane while a second SFE pump maintained the desired back pressure on the permeate side of the membrane.; A model oil consisting of soybean oil triacylgycerols (TAGS) and added free fatty acids (FFA as oleic acid) was used. An evaluation of the solubility of soybean oil, oleic acid and linoleic acid in supercritical carbon dioxide provided the appropriate temperature and pressure conditions to use for the membrane separation. Data obtained from the solubility tests showed the best operational conditions in terms of temperature and pressure 45°C and 306 atm, respectively. |
