Hem Joshi1, Terry Walker1, and Bryan R. Moser2. (1) Biosystems Engineering, Clemson University, 111 Biosystems Research Complex (BRC), Clemson, SC 29634, (2) National Center for Agricultural Utilization Research, United States Department of Agriculture, Agricultural Research Service, Room 2201, 1815 N University St, Peoria, IL 61604
Canola oil was transesterified using a 1:1 mole mixture of methanol and ethanol (M/E) with potassium hydroxide (KOH) catalyst. Effect of catalyst concentration (0.5 to 1.5 % wt/wt), mole ratio of M/E to canola oil (3:1 to 20:1) and reaction temperature (25 to 75 °C) on the percentage yield measured after 2.5 and 5.0 minutes were optimized using a central composite design. Maximum percentage yield of 98 % was predicted for catalyst concentration of 1.1 wt % and M/E to canola oil mole ratio of 20:1 at 25 °C at 2.5 minutes, whereas a maximum percentage yield of 99 % was predicted for a catalyst concentration of 1.15 wt % and all mole ratios of reactants at 25 °C at 5 minutes. Statistical analysis demonstrated that, increasing catalyst concentration and mole ratio of reactants resulted in curvilinear and linear trends in percentage yield, both at 2.5 minutes and 5 minutes. However, reaction temperature, which affected percentage yield at 2.5 minutes linearly, was insignificant at 5 minutes. The resultant mixed methyl/ethyl canola esters exhibited enhanced low temperature performance and lubricity properties in comparison to neat canola oil methyl esters and also satisfied ASTM D 6751 and EN 14214 standards with respect to oxidation stability, kinematic viscosity, and acid value.
