Biodiesel Synthesis and Characterization from Waste Castor Oil Seed Biomass Utilizing Afzelia Africana Seed Husk Derived Nano Catalyst for Enhanced Transesterification Efficiency

Abstract

This study focused on the production of biodiesel from castor seed oil using Afzelia Africana seed husk ash (AASHA) as a heterogeneous catalyst. The physicochemical properties of the castor seed oil and the catalyst were characterized. The effects of process variables such as methanol/oil molar ratio, catalyst concentration, reaction temperature, reaction time, and agitation speed on the biodiesel yield were investigated. Response surface methodology (RSM) was employed to optimize the production process. The optimal conditions were found to be: methanol/oil molar ratio of 10.4:1, catalyst concentration of 2.19 wt%, reaction temperature of 63°C, reaction time of 1.5 hours, and agitation speed of 394 rpm, which resulted in a biodiesel yield of 90.9%. The properties of the produced biodiesel, such as density, viscosity, flash point, cetane number, and acid value, were within the American Society for Testing and Materials (ASTM) standards for biodiesel. Gas chromatography-mass spectrometer (GC-MS) analysis confirmed the conversion of the fatty acids in the castor seed oil to their corresponding methyl esters. The Fourier Transform Infrared Spectroscopy (FTIR) analysis further supported the successful transesterification of the oil. The study demonstrates the feasibility of using AASHA as an effective and eco-friendly catalyst for the production of high-quality biodiesel from castor seed oil.