Microwave-assisted synthesis of glycerol carbonate by transesterification of glycerol using Mangifera indica peel calcined ash as catalyst

Abstract

For the first time, application of Mangifera indica peel calcined ash (MIPCA)-a biomass-derived heterogeneous solid base catalyst is researched for glycerol transesterification with dimethyl carbonate (DMC) to synthesize glycerol carbonate (GC) under microwave irradiation. The appreciable high basicity due to the presence of K2O, CaO and MgO; substantial surface area and mesoporous nature of MIPCA efficiently facilitates the glycerol conversion. Furthermore, the catalyst being biowaste, is hence readily available, economical, biodegradable and environmentally benign. Under the optimum reaction conditions of 3:1 M ratio of DMC: glycerol, 6 wt% catalyst concentration, 80 °C temperature and 50 mins time, microwave irradiation exhibits high conversion (98.1 ± 0.6 %) and improved selectivity (100 %). 1H and 13C NMR were used to characterise the synthesised GC. The catalyst's reusability ensures that it sustains its catalytic activity for up to five consecutive cycles, which is crucial for glycerol to GC transesterification.