Empirical Modeling of the Enzymatic Methanolysis of Canola Oil

A statistics based design of experiments Central Composite Design, CCD was used in the present work to develop an empirical model for describing, quantitatively, the methanolysis reaction of canola oil by the commercially immobilized Candida antarctica lipase, i.e. Novozym 435 in a solvent-free system. The reaction factors under study were the amount of enzyme x1, temperature of operation x2 and the molar ratio of methanol to canola oil x3. The yield of methyl ester was evaluated using a second-order polynomial multiple regression model. An analysis of variance ANOVA showed a high coe cient of determination R2 value of 0.987, thus, ensuring a satisfactory adjustment of the regression model with the experimental data. The positive sign for the coe cients of the amount of enzyme and the temperature of the reaction indicated that the yield of the methyl ester increased with increased levels of x1 from 3 to 5 and factor x2 from 25 to 35 C. The negative e ect of the methanol to canola oil ratio on the methyl ester yield indicated that the response level decreased as this factor x3 increased. The methyl ester yield, 84.42%, as the highest value obtained through experiment that was in agreement with the predicted yield 89.15%, resulted with use of the optimized operative parameters when enzyme amount, reaction temperature and methanol to canola oil molar ratio were 5%, 38 C and 3, respectively.