Optimization of the Sono-Biodiesel in the Attendance of ZnO Nanoparticles, Process Yield Enhancement: Box Behnken Design

The growing fuel demands and drastic restrictions of politics on greenhouse gas emissions are motivating bioenergy research. In this paper, the yield improvement of the produced biodiesel from canola oil using the transesterification process, in attendance of ZnO nanocatalyst and ultrasound waves, was investigated. The crystal size, morphology, and particle size of the prepared nanoparticles were recognized by applying X-ray diffraction (XRD), scanning electron microscopy (SEM), and transverse electron microscopy (TEM) analyses, respectively. The size of ZnO nanoparticles was 45 nm with a hexagonal-shaped structure. The response surface methodology (RSM) and the Box Behnken design (BBD) were employed to analyze the impact of the independent variables on biodiesel production yield. The reliability of the proposed model was verified by applying the analysis of variance (ANOVA) to evaluate response. Regarding the yield, satisfactory accordance was obtained between the calculated and prognosticated data from RSM, with R^2= 0.9910 and R^2 adj= 0.9748. The optimum reaction conditions were acquired at a methanol to oil molar ratio of 11.19:1 mol: mol, ultrasound irradiation time of 31.98 min, and nanocatalyst amount of 3.17 wt.%. The optimum value for the sono-biodiesel yield was achieved equal to 90.16%. Moreover, the kinetic study exhibited that the values of activation energy and Arnius frequency factor were achieved 46.23 kJ mol^-1 and 5.83× 105 min^-1, respectively. Accordingly, this research indicated that ZnO nanoparticles can be utilized as a promising and efficient heterogeneous catalyst for biodiesel production.