Optimization study on the conversion of restaurant waste oil to fatty acid methyl esters using a modified catalyst derived from banana peel

Accumulated banana peels and restaurant oil poses environmental threat, and necessitates innovative strategies for its management and utilization. We produced restaurant waste oil biodiesel using banana peels-based heterogeneous catalyst. The catalyst was characterised using Fourier Transform Infrared Spectroscopy (FT-IR), X-Ray Diffraction (XRD), Thermo Gravimetric Analysis (TGA), and Scanning Electron Microscopy - Energy dispersive x-ray analysis (SEM-EDX). Taguchi design approach was employed to model and optimize the transesterification process by varying reaction time, reaction temperature, methanol-to-oil ratio, and catalyst concentration. The highest biodiesel yield of 99.8% was achieved in 80 mins, 35 °C, 2.5 wt% of catalyst, and a methanol-to-oil ratio of 12:1. Under optimal conditions, the predicted yield was 98.2%, with a methanol-to-oil ratio of 9:1, a catalyst loading of 3.5 wt%, and a reaction time of 80 mins at 35°C. These developments can address issues related to environmental pollution and sustainable fuel generation, as well as support a circular economy. Future studies should investigate various modifications of banana peel catalysts, such as varying the calcination temperature and the type of metal oxides used for impregnation, to improve catalytic activity and stability.