Biodiesel proauction by in situ transesterification of Jatropha Curcas L. seeds

The main disadvantage of using biodiesel is its price, which is due to high costs of raw material and oil conditioning to obtain biodiesel by conventional transesterification, which prevents it from competing with fossil fuels. An alternative method was investigated to obtain biodiesel by in-situ transesterification or reactive extraction (RE) from Jatropha Curcas L. seeds. This alternative process seeks to reduce stages in the production process, and thus, reduce operational costs with respect to the conventional method. The influence of temperature, catalyst mass concentration (g NaOH/g oil), and methanol to oil molar ratio, in order to maximize yield and FAME concentration of biodiesel obtained, was determined through a central composite design (DCC) with response surface methodology. The most appropriate conditions to obtain biodiesel by in-situ transesterification occur at 44 degrees C, with a mass concentration of catalyst 1,2 g NaOH/100 g oil, and with a methanol to molar ratio of 135:1 with the presence of hexane, keeping constant stirring speed (635 rpm) and reaction time (3h). In these conditions, a yield of 71,99% w/w (g biodiesel/g oil) and a FAME content of 90,36% w/w (g FAME/g biodiesel) were reached. The results of this study provide an alternative process for obtaining biodiesel without the need of extraction and pretreatment stages employed in the traditional method, in addition to reducing excess washes in the conventional process, which increase process costs and environmental impact.