Parametric study and optimization of in situ transesterification of Jatropha curcas L assisted by benzyltrimethylammonium hydroxide as a phase transfer catalyst via response surface methodology

In the present work, non-edible oil source, Jatropha curcas oil was used with base catalyzed methanol and ethanol to produce biodiesel using in situ transesterification assisted by Benzyltrimethylammonium hydroxide (BTMAOH) as a phase transfer catalyst (PTC). Experimental investigation showed that base catalyzed in situ transesterification reaction rate was enhanced with the use of BTMAOH as a PTC. During the experiment fast formation of biodiesel was observed in relatively shorter time for PTC assisted reaction as compared to the reaction in the absence of PTC. The effect of individual reaction parameters was investigated using response surface methodology (RSM). Optimum operating conditions were also found statistically. Weight fractions of 89 ± 0.7% fatty acid methyl esters (FAME) yield and 99.4 ± 0.4% fatty acid ethyl esters (FAEE) yield were produced at optimum reaction condition. The fuel quality of FAME and FAEE was investigated against the fuel quality specification set by ASTM D6751 and EN-14214 standards.

► Higher yields of biodiesel were obtained when the reaction was catalyzed with NaOH in the presence of BTMAOH as a PTC.
►  Model equations and optimum operating conditions for biodiesel yields were statistically established using RSM.
► Use of BTMAOH as a PTC is promising to enhance the reaction rate of alkaline in situ transesterification.
► Higher biodiesel yield was obtained using in situ ethanolysis as compared to in situ methanolysis.
► Reaction mechanism of BTMAOH as a PTC is developed for in situ transesterification of Jatropha curcas L.