A utilização de lipases imobilizadas em reações de esterificação em meio não aquoso

Abstract

The purpose of this work was to study the performance of two lipases, Lipozyme and Novozym 435, in lipase-catalyzed esterifications in nonaqueous medium. The focus of this study was the enzimatic synthesis of n-butyl oleate. A pervaporation reactor was set up to carry out the reactions. Pervaporation selectively removes water from the reaction mixture using a nonporous polymeric membrane, cellulose acetate. Conversions were determined by the cupric acetate method. In the synthesis of n-butyl oleate catalized by Lipozyme, the lipase activity decreased with an increase in the reaction temperature. Maximum activity was achieved at 30°C. At 60°C the activity was minimal. The decrease in reaction mixture viscosity by addition of a solvent caused a great increase in conversion. On the other hand, increments on the amount of enzime used in the reaction mixture did not affect the formation of products. In the synthesis of n-butyl oleare using Novozym 435, the enzimatic activity was the same in the range between 30°C-60°C. The conversion was directly proportional to the amount of enzyme until the limit of 10% (m/m) on oleic acid. Changes on the viscosity and amount of butanol did not affect the reaction productivity