Biodiesel Production Using a Banana Peel Extract-Mediated Highly Basic Heterogeneous Nanocatalyst

Greener methods for the production of nanoparticles (NPs) are highly investigated to minimize the harmfulness of chemical synthetic processes. In this study, CaO (calcium oxide) NPs were synthesized using extracts of banana (Musa acuminata) leaves. The precipitate of Ca(OH)2 (calcium hydroxide) obtained from the precursor Ca(NO3)2 (calcium nitrate) was calcined at 900 °C in a muffle furnace to form CaO. The catalytic activity of the prepared CaO was studied in transesterification of soybean oil. From the 1H-NMR analysis, a high soybean oil conversion of 98.0% was obtained under the optimum reaction conditions of 8 wt% of catalyst loading, 2 h reaction time, and a 15:1 methanol to oil molar ratio at 65 °C temperature. 1H-NMR, 13C-NMR, and FT-IR spectroscopic studies of the product proved the formation of biodiesel. The CaO nanocatalyst was characterized using XRD, SEM-EDS, TEM, FT-IR, XPS, and BET analyses. The average diameter of the catalyst was determined as 46.2 nm from TEM analyses. The catalyst can be used successfully even after five active reaction cycles without substantial loss in the activity of the catalyst.