Effects of Process Parameters on Biodiesel Production from Refined Soy Oil.

In this study, the effects of process variables such as methanol-to-oil molar ratio, catalyst amount, and reaction temperature on the transesterification of the refined soy oil to biodiesel were investigated. Methanol with potassium hydroxide (KOH) as a homogenous catalyst was used for the transesterification process at a time of 1hr and 250rpm stirring speed. Factorial design was applied at two levels of methanol-to-oil molar ratio of (1:1-6:1), catalyst % of (0.5-1.0) and reaction temperature of (3550oC) as independent variables and refined soy oil biodiesel yield as dependent variable (response). A statistically significant (P<0.0001) linear regression model was obtained for biodiesel production (using Design-Expert ® statistical program (v.8.0.2) and verification experiment confirmed the validity of the predicted model. In addition the fuel properties of the produced biodiesel were investigated and compared with the standards. The optimum combinations for transesterification to achieve a maximum biodiesel yield of 97% were found to be methanolto-oil molar ratio, 6:1; catalyst amount of 1.0% and a reaction temperature of 35 o C