Optimization of Biodiesel Production from Castor Oil by Response Surface Methodology

This work investigated the possibility of using response surface methodology based on a four factor five level central composite design to optimize biodiesel production from castor oil.The reaction variables were oil: ethanol ratio, lipozyme concentration, time and temperature.The properties of the biodiesel produced were assessed.The linear coefficient of lipozyme 2 concentration (B), temperature (D), the quadratic coefficient of lipozyme concentration (B ), time 2 2 (C ), temperature (D ), the interaction of oil/ethanol ratio and lipozyme concentration (A*B), the interaction of lipozyme concentration and time (B*C) had significant effect on the biodiesel yield (p<0.05).The other variableswere not significant (p>0.05).The specific gravity was (0.91), refractive index (1.41+ 0.01), viscosity (14.1), cetane number (53.9), calorific value (38.0+ o o 0.10), flash point (150 C), cloud point (7 C) iodine value (101 + 0.53), acid value (0.57 + 0.01), and saponification value (180+0.25).Maximum yield was found to be 93.0%under the conditions of oil: ethanol ratio of (1:7.14),lipozyme concentration (40 U), time (165 min) and temperature o 50 C.The properties of the biodiesel produced were largely in conformity with ASTM D6751 standards.