Studying the ultrasonic assisted transesterification of castor oil by using factorial design for optimization of biodiesel production

Abstract

This work presents the biodiesel production from castor oil with methanol in presence of potassium hydroxide as catalyst at room temperature using ultrasonic bath. A factorial design of experiments and a central composite design have been used to evaluate the influence of operating conditions on biodiesel synthesis from inedible castor oil. The response chosen was viscosity while the variables studied were catalyst concentration and the methanol/vegetable oil molar ratio at room temperature in an ultrasonic bath. The methanol/vegetable oil molar ratio is the most important factor, having a negative influence on viscosity.
The catalyst concentration has a small negative influence on viscosity and this is attributed to the presence of ultra-sonification. A second order model was obtained to predict the produced biodiesel viscosity. Within the experimental range studied the model matched the results from the experiments.