Biodiesel production from Sterculia striata oil by ethyl transesterification method

Biodiesel is an alternative to fossil fuels. Its industrial production relies on vegetable oil transesterification with a short-chain with ethanol using sodium hydroxide (NaOH) as the catalyst. The growing demand for biofuels has motivated studies on new vegetable oil sources. Sterculia striata (Chicha) seeds are particularly interesting in this sense-their mass consists of about 40% oil, so it is possible to convert them into biodiesel in high yield. Hence, this manuscript aimed to investigate how process variables affect biodiesel production from chicha oil. Application of a factorial design technique aided analysis of four process variables: temperature (30-70 °C), oil/alcohol molar ratio (1:6-1:10), catalyst amount (0.5-1.5% w/w), and reaction time (0.5-2.0 h). The resulting biodiesel met most of the standard requirements; however, its density lay above the values established by the Brazilian petroleum agency. Considering variables evaluated the best conditions were temperature = 30 °C, oil/alcohol molar ratio = 1:10, 1.5% catalyst in relation to oil (w/w), and reaction time = 30 min.