Boosted conversion of restaurant waste oil into biodiesel using Fe3O4@UiO-66-NH2 magnetic heterogeneous nanocatalyst and its application on the diesel engine: Optimization via RSM

In this scientific study, Fe3O4@UiO-66-NH2 nanoparticles were prepared and applied as an efficient and magnetic nanocomposite to synthesize biodiesel from restaurant waste oil via microwave irradiation. Various techniques were employed to describe the nanocomposite structure, such as FTIR, BET, SEM, XRD, CO2-TPD, TEM, EDX/Mapping, and VSM. The greatest biodiesel efficiency via Fe3O4@UiO-66-NH2 under optimal circumstances including methanol to waste oil proportion of 11.38:1, time of 8.84 min, nanocatalyst amount of 3.27%, and stirring speed of 723.38 rpm) was 98.72%, which is a substantial performance. Besides, the Fe3O4@UiO-66-NH2 nanocatalyst was applied in seven reutilizing processes with a remarkable output, hence after the 7th round, its methyl ester purity was more than 90%, confirming the high reusability of the Fe3O4@UiO-66-NH2 nanocatalyst. In addition, kinetic and thermodynamic examinations of transesterification of waste oil applying Fe3O4@UiO-66-NH2 nanocatalyst were executed, and the outputs demonstrated that the reaction is endothermic. Moreover, different proportions of biodiesel and diesel at various torques were experimented on the compression-ignition engine performance (i.e. EGT, BTE, and BSFC) also the emission of harmful pollutants (i.e., CO2, CO, UHC, and NOx). The outputs indicated that adding biodiesel and Fe3O4@UiO-66-NH2 nanocatalyst to diesel has favorable impacts on the diesel engine characteristics.