Submitted to: Supercritical Fluids International Symposium
Publication Type: Abstract Only
Publication Acceptance Date: 3/31/1996
Publication Date: N/A
Technical Abstract: Reaction chemistry in supercritical fluid media holds considerable promise in the preparation of derivatives for analysis, structural identification of unknown compounds, and mixtures, and for enhancing the solubility of solute in supercritical fluids. In our laboratory, lipase-initiated catalysis in SC-CO2 has been shown to be a facile route for the production of esters, monoglycerides, and for conducting interesterifications. Esters can be conveniently synthesized by blending both reactants with the aid of syringe pumps before transesterification is accomplished over an enzyme bed packed in a conventional SFE cell. A simple agitated microautoclave system can be fashioned from commercial SFE instrumentation, permitting the synthesis of simple esters in over 90% yield in less than 15 minutes. Monoglyceride synthesis is facilitated by using two syringe pumps, one to a vegetable oil, while the other delivers an excess of glycerol into a tee arrangement, with subsequent transport of the mixture across the enzyme-laden bed. A similar dual syringe pump approach has also been used for mixing and transporting oils for enzymatic interesterification. As in similar reactions conducted in the condensed state, high water concentrations are inhibitory to enzyme activity and alcoholic reagent addition must be optimized with respect to oil flow and enzyme mass for optimal production of esters.