Zahra Abbasi - Faculty of Science, Ayatollah Boroujerdi University, Lorestan, Iran
Elisa I. Garcia-Lopez - Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Viale delle Scienze, ۹۰۱۲۸ Palermo, Italy
Giuseppe Marcì - “Schiavello-Grillone” Photocatalysis Group, Department of Engineering, University of Palermo, Viale delle Scienze, ۹۰۱۲۸ Palermo, Italy
Mehdi Ahmadi - Environmental Technologies Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran

Diesel fuel can be substituted with biodiesel fuel. Burning biodiesel results in less pollution because its source is vegetable or animal fat. Waste cooking oil (WCO) was utilized in this study as a raw source to produce biodiesel. In the WCO under study, the percentage of free fatty acids (FFAs) was ۴.۰۹%. The process of turning used cooking oil waste into biodiesel involved two steps. The initial phase was studying the photocatalytic esterification of methanol with FFAs in WCO under visible irradiation using Cr (x%)-TiO۲. Triglycerides and methanol were transesterified in the second stage, which was catalyzed by NaOH. When TiO۲ was present, efficiency was shown to increase by ۱۰% when compared to the absence of a photocatalyst. Cr-TiO۲ photo-esterification reaction has an equivalent order of one. The realisation of the reaction under mild conditions was confirmed by the activation energy of ۳۱.۳۶ kJ/mol needed for the Cr-TiO۲ photocatalyst to photo-esterify WCO. Our hypothesis for the esterification process took into account the formation of H+, CH۳OO·, and R-COOH on the photocatalyst surface. OH- was thought to be the active species in the transesterification reaction process. The density of the produced biodiesel was ۰.۸۹ g.cm-۳, per the data that were obtained. For biodiesel, the results yield a falling point of -۵ and a cloud point of ۰, respectively. The biodiesel made from waste oil had a viscosity of ۴.۱ mm۲.s−۱, which was within the standard range. The biodiesel sample made from waste oil has an acid value of ۰.۳۸ mg KOH

Biodiesel, Two dimensional, photocatalyst, Waste oil, Kinetics, Esterification