Efficient and green production of biodiesel catalyzed by recyclable biomass-derived magnetic acids

Abstract

Biomass-based catalysts are considered as non-toxic, non-corrosive and eco-friendly solid materials. In the present study, all investigated biomass-derived magnetic sulfonic acid catalysts were synthesized from renewable chitosan, and characterized by XRD, FT-IR, TGA, VSM, SEM, TEM, and BET. Biodiesel was prepared by esterification of oleic acid and methanol to test the catalytic performance of the catalysts. Among the employed catalytic materials, a novel magnetic catalyst (FCHC-SO3H) was found to show predominant catalytic performance to produce biodiesel. Under the optimum reaction conditions (15/1 methanol/oleic aicd mole ratio and 4 wt% catalyst dosage at 80 °C for 3 h), a high biodiesel yield of 96.7% was obtained over FCHC-SO3H. It was found that the reaction catalyzed by the FCHC-SO3H material obeyed the first-order kinetics with low activation energy of 37.5 kJ/mol. In addition, the catalyst could be reused for five consecutive recycles, while maintaining good activity and stability. Therefore, FCHC-SO3H can be a promising catalyst for efficient production of biodiesel from highly acidic feedstocks.