A sustainable protocol for production of biodiesel by transesterification of soybean oil using banana trunk ash as a heterogeneous catalyst

Due to the world wide attention regarding depletion of non-renewable resources, detrimental effect of toxic chemicals to the environment and uncontrollable up surge of waste materials, scientific community is showing substantial focus on valorization of waste into various significant products. In this study, Musa acuminata banana trunk ash (MBTA) was utilized as a waste biomass-derived heterogeneous catalyst for transesterification of soybean oil to biodiesel at ambient temperature. To characterize the solid catalyst, different analytical and spectroscopic techniques were adopted that enabled to investigate its chemical composition and morphology. EDX, XRF, and XRD analysis revealed the presence of several oxides of alkali metals and alkaline earth metals besides carbon in the ash sample. A high conversion of biodiesel (98.39%) was achieved under our optimized reaction conditions using the waste biomass catalytic system. The catalyst was recoverable up to 5 times without much depreciation in its catalytic activity. The catalyst being a waste-material is therefore cheap, easily-to-prepare, biodegradable, recyclable, and environmentally benign which makes it a prospective candidate for "green catalyst" in biodiesel synthesis.