Enzymatic Esterification of Glycerol and Stearic Acid in Non-conventional Media.

Ionic liquids as trihexyl-tetradecyl-phophonium-dicyanamide (Cyphos 105) and cocosalkyl-pentaethoxi-methyl-ammonium-methosulfate (Ammoeng 100) were applied for the esterification of stearic acid and glycerol using Candida antarctica lipase (Novozyme 435). When only ILs were applied as solvents at 1:15 initial substrate molar ratio the conversion was 76 and 78 % in the case of two kinds of ILs, respectively. Mixed the ILs and supercritical CO2 the conversion reached 79 and 86 %. The conversion was found highest in supercritical CO2, reached 90 %. Moreover formation of glycerol-di-stearate is much lower in the case of ILs comparing with SCCO2.