Synthesis of oleic acid esters catalyzed by immobilized lipase

Lipase-catalyzed syntheses of oleic acid esters with various primary alcohols have been performed in a batch stirred tank reactor in an almost nonaqueous medium without organic solvents. For all syntheses 50 degrees C was found to be the optimal temperature. Initial reaction rates were influenced by the alcohol chain length. The study of the pressure stability of the immobilized lipase from Rhizomucor miehei (lipozyme IM) showed that the lipase preparation is quite stable; it does not lose its activity when it is exposed to carbon dioxide at 300 bar for 24 h. Esterification rates at high pressure were determined, and it was found that they were higher than at atmospheric pressure. The highest rate and maximal conversion were near the critical point of carbon dioxide.