Renewable feedstocks and agricultural catalysts: Transforming biodiesel production

The sustainability of the energy supply has grown significantly from economic, environmental and public health standpoint. This has accelerated the search for renewable and sustainable energy alternatives. Due to challenges with feedstock availability, land use, the food vs. fuel dilemma and generation costs, biodiesel's economic and environmental sustainability is debatable. Apart from feedstock concerns, the cost of biodiesel is greatly impacted using catalysts. Recent studies have demonstrated that agricultural waste can be converted into efficient heterogeneous catalysts that are both cost-effective and environmentally sustainable. These waste-derived catalysts have achieved biodiesel yields of 85–98 % while reducing catalyst preparation costs by approximately 30–60 % compared with conventional catalysts. This review comprehensively summarises recent advances in the conversion of agricultural residues into efficient catalysts for biodiesel production. It includes important components like life cycle assessments (LCA), feedstock development, catalyst synthesis, comparative performance and economic viability. Significant developments in the catalytic use of many agricultural by-products are carefully examined.