PROCESS OPTIMIZATION OF BIODIESEL PRODUCTION USING ALKALINE CATALYSTS英文电子书.pdf

PROCESS OPTIMIZATION OF BIODIESEL PRODUCTION USING ALKALINE CATALYSTS A. Singh, B. He, J. Thompson, J. Van Gerpen ABSTRACT. The most commonly used method for biodiesel preparation is via transesterification of vegetable oil using alkaline catalysts. Biodiesel yield and oil conversion are affected by operating conditions including the catalyst formulation and concentration. Application of alkaline catalysts can also lead to undesired soap formation. This study evaluated the alkaline catalyst effects on biodiesel yield and soap formation in transesterifying methanol and canola oil at different catalyst concentrations, reaction temperatures, and methanol-to-oil molar ratios. Four different alkaline catalysts, i.e., potassium hydroxide, sodium hydroxide, potassium methoxide, and sodium methoxide, were studied and compared on molar basis through a 4-factor 3-level experimental design. It was observed that methoxide catalysts led to better biodiesel yields than hydroxide catalysts. The methoxide catalysts not only accelerated the reaction but also elevated the conversion equilibrium. Based on statistical optimization, the operating conditions for maximizing biodiesel yield and minimizing soap formation were potassium methoxide as catalyst at 0.2 mol/mol (1.59%wt), reaction temperature of 50 C, and methanol-to-oil molar ratio of 4.5:1. Experimental verification gave 95.8% biodiesel yield and 0.75%wt soap. Keywords. Biodiesel, Alkaline catalyst, Transesterification, Canola oil. everal ways have been researched and demonstrated in the system by reacting with esters and triglycerides for preparing biodiesel from virgin and waste vege- directly. On the other hand, the water problem can be avoided table oi