Synthesis of MgO/ZSM-5 catalyst and optimization of process parameters for clean production of biodiesel from Spirulina platensis

摘要

With the further expansion of the fossil crisis and the increasing demand for biodiesel, it is imperative to develop highly reusable catalysts. Therefore, in this study, the completed synthesis of MgO/ZSM-5 catalysts via impregnation and ultrasonic dispersion methods were achieved to be applied in the clean production from Spirulina platensis-derived biodiesel. Physiochemical analyses including thermogravimetry (TG), temperature programmed desorption of CO2 (CO2-TPD), X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR) and Brunauer-Emmett-Teller surface area (BET) were used to define the basicity, structure, composition and morphology of synthesized catalysts. The optimum process conditions obtained by Taguchi method were as follows, the molar ratio of ethanol to oil was 15/1, the catalyst concentration was 3 wt%, and the yield of biodiesel reached 92.1% after 1 h reaction at 75 degrees C. The optimal catalyst had strong stability and catalytic activity in the repeated cycle test, even after five cycles, the yield of biodiesel was still above 85%. The transesterification of Spirulina oil catalyzed by MgO/ZSM-5 catalyst accorded with the pseudo-first-order kinetics, and the activation energy was 49.67 kJ/mol. Finally, the economic feasibility analysis of biodiesel illustrated that the new supported catalyst can effectively reduce the cost of production and provide favorable support for the future continuously industrial production. (C) 2020 Elsevier Ltd. All rights reserved.