HYDROLYSIS OF VEGETABLE-OILS IN SUBCRITICAL AND SUPERCRITICAL WATER

Water, in its subcritical state, can be used as both a solvent and rea ctant for the hydrolysis of triglycerides. In this study, soybean, lin seed, and coconut oils were successfully and reproducibly hydrolyzed t o free fatty acids with water at a density of 0.7 g/mL and temperature s of 260-280 degrees C. Under these conditions the reaction proceeds q uickly, with conversion of greater than 97% after 15-20 min. Some geom etric isomerization of the linolenic acids was observed at reaction te mperatures as low as 250 degrees C. Reactions carried out at higher te mperatures and pressures, up to the critical point of water, produced either/or degradation, pyrolysis, and polymerization, of the oils and resultant fatty acids.