Processing of Unsaturated Fatty Acids in Supercritical Carbon Dioxide

Currently, lipids derived from plants, animals, and microorganisms are being considered as promising renewable feedstocks to synthesize a wide range of fuels and chemicals. For example, many lipid sources contain unsaturated fatty acids, which can be oxidized to form a variety of products such as diacids and epoxides. These chemicals are valuable intermediates for the formulation of pharmaceuticals, herbicides, detergents, plasticizers, lubricants, paints, and other useful products. The use of supercritical fluids, such as carbon dioxide (SC-CO₂), in processing lipid components is being heavily researched; however, experimental solubility data primarily exists for lipids composed of higher molecular weight fatty acids such as oleic acid. In this research, the solubility of small-chain fatty acids in SC-CO₂ was determined experimentally and the applicability of common solubility models was evaluated. Additionally, this paper will show how supercritical carbon dioxide can be used to enhance fatty-acid oxidation with potassium permanganate.