Transesterification of Used Cooking Oils Catalyzed by CsTPA/SBA15 Catalyst System in Biodiesel Production

Abstract

An environmentally beneficial, facile and clean method for the production of Biodiesel from Used Cooking Oils have been developed. Owing to corrosion and re-usability problems associated with the alkali catalysts like NaOH and KOH, a novel Heteropolyacid Cesium substituted do-decatungstophosphoric acid (CsTPA) on SBA 15 was synthesized. A process for the production of Biodiesel from Used Groundnut Oil(UGO), Used Sunflower Oil(USO) and Used Palm Oil(UPO) has been studied and the reaction conditions that affect the yield and purity of product esters like the concentration of catalyst, methanol:oil molar ratio, reaction time and temperature were optimized. Performance of the catalyst was compared with that of the conventional alkali catalysts and it was found that the proposed heteropolyacid catalyst system gave higher yield of 91.5% for UPO. The catalyst activity did not vary much even after reusing the recovered catalyst system for up to three runs. The fuel properties for the Used Cooking Oil esters produced were found to be in agreement with ASTM standards. Comparative performance and emission study of UCOs with diesel was carried out to check the effect of CO, CO2 and NOx.