From waste to fuel: Waste-derived CH3ONa modified ZSM-5 catalyst for efficient biodiesel production from waste cooking oil (WCO)

This study explores the production of biodiesel from waste cooking oil (WCO) using a novel Na-alkoxide-modified ZSM-5 catalyst synthesized from pure silica extracted from coal fly ash. This approach mitigates both the high cost of conventional biodiesel production and the environmental impact of waste disposal. The ZSM-5 catalyst was modified via refluxing with aqueous sodium methoxide, enhancing its basicity and catalytic efficiency. Characterization techniques (XRD, SEM, and FTIR) confirmed the successful incorporation of sodium methoxide and structural modifications. Transesterification was conducted using the modified catalyst, WCO, and methanol, yielding biodiesel characterized by 1 H NMR, 13 C NMR, FTIR, and GC-MS, alongside physicochemical property analysis. NMR confirmed a high triglyceride-to-methyl ester conversion of 96.6%, exceeding the EN 14214 standard of 96.5%. GC-MS identified the fatty acid methyl esters (FAMEs), aligning with WCO-derived biodiesel profiles. This study highlights the viability of a waste-derived catalyst for cost-effective, sustainable biodiesel production, offering an environmentally friendly alternative to conventional methods.