α‐ZrP nanoparticles as an efficient nanocatalyst in the simultaneous esterification and transesterification reaction of waste cooking oil with high free fatty acid content for biodiesel production

Abstract Biodiesel is renewable and green energy. In this study, solid acid hexagonal α-zirconium phosphate (α-ZrP) nanoparticles, as recyclable and effective catalyst, were prepared by reflux method, and this solid acid catalyst was utilized for esterification and transesterification of waste cooking oil (WCO) that comprise high free fatty acid (FFA) with methanol in order to produce biodiesel. The catalyst was characterized by several physicochemical procedures. Quality estimation of WCO methyl ester demonstrated good compliance with both international standards (EN14214 and ASTM D6751). The results proved that α-ZrP is an effective catalyst for simultaneous esterification and transesterification of WCO.