Advanced supercritical Methyl acetate method for biodiesel production from Pongamia pinnata oil

At present, alkali-catalyzed transesterification process is widely used in biodiesel production. However, in this process up to 88% of total production cost is for the feedstock, due to the requirement of using low free fatty acid (FFA) content feedstocks that are commonly attributed to refined edible plant-oils. This work was, therefore, carried out to know the potential use of non-edible Pongamia pinnata oil in biodiesel production. Instead of using a transesterification, this work applied an interesterification process called one-step supercritical methyl acetate method under reaction condition of 300 degrees C/20 MPa/45 min/42 M ratio in methyl acetate to oil. In this glycerol-free method, 10wt% aqueous acetic acid was added as an additive to proceed the interesterification process under such reaction condition. It was found out that high FFA content in Pongamia pinnata oil did not give any adverse effect on the process as the highest yield of 96.6wt% FAME and 11.5wt% triacetin (total 108.1wt%) was achievable. Both products were miscible and their evaluation on biodiesel properties showed the compliance towards biodiesel standards. (C) 2015 Elsevier Ltd. All rights reserved.