Zinc aluminate nanoparticles: Preparation, characterization and application as efficient and economic catalyst in transformation of waste cooking oil into biodiesel

In this study, an efficient and economic transesterification process for waste cooking oil (WCO) using methanol was contemplated. The process was preceded using zinc aluminate nanoparticles as heterogeneous catalyst. High purity porous ZnAl2O4 nanoparticles with polycrystalline nature were effectively prepared using co-precipitation technique at two annealing temperatures of 700 and 800 degrees C. The prepared ZnAl2O4 nanoparticles were described using FTIR, XRD, EDX, and SEM spectroscopy. The structure, morphological and chemical properties of the ZnAl2O4 catalyst annealed at 800 degrees C showed high reactivity compared to that annealed at 700 degrees C. The transesterification process parameters were studied, including catalyst dose, conversion temperature, time of the process, and the ratio of oil to methyl alcohol. The optimized process conditions were produced a maximum biodiesel yield of 94.88% after 3 hat 100 degrees C using 5 wt% catalyst and 1:18 oil/methanol ratio. The physicochemical properties of the obtained biodiesel were in accordance with the biodiesel standards D-6571 (ASTM) and the Egyptian standards EN 14214. (C) 2019 Elsevier B.V. All rights reserved.