Biodiesel production from a non-edible source of royna (Aphanamixis polystachya) oil

Abstract

Background: Rapid consumption of fossil fuels as well as rising environmental deterioration caused by extreme CO2 emissions has become crucial in searching for a clean and renewable energy source such as biodiesel. The current work is an attempt to produce biodiesel from a potential non-edible feedstock of Aphanamixis polystachya, locally known as ‘Royna’ seed oil in Bangladesh. Methods: Royna oil was extracted from the seed by Soxhlet extraction method. Biodiesel was synthesized by a three-step process: saponification of oil, followed by acidification of the soap, and esterification of the free fatty acid (FFA). Results: The result presented showed that royna seed was found to be rich in oil with a maximum yield of 51% (w/w). Several reaction parameters were optimized during biodiesel production in their percentage proportion of oil to a catalyst (1:2), soap to HCl (1:1.5), FFA to an alcohol molar ratio (1:7), and catalyst (1 wt%). As a result, the highest yield of 97% was obtained from 7.5 wt% FFA content oil at 70 °C for 90-min reaction time. ASTM verified standard methods were employed to analyze the physicochemical properties of the as-prepared biodiesel. The structural and surface properties of the royna oil and as-prepared biodiesel were determined by 1H NMR and FTIR spectroscopic methods indicating a complete conversion of oil to biodiesel. Conclusions: The study investigated the promising viability of royna oil to biodiesel using a three-step conversion route along with the heterogeneous catalysis system to circumvent the current environmental issues.