Mojapelo, NASeroka, Ntalane SKhotseng, L2025-03-192025-03-192025-030961-95341873-2909https://doi.org/10.1016/j.biombioe.2025.107664http://hdl.handle.net/10204/14181The world energy crisis and environmental issues resulting from fossil fuel depletion and increased greenhouse gas emissions have prompted extensive study into alternative, ecologically friendly energy sources. Interest in environmentally friendly and renewable energy, such as biodiesel, has grown significantly over fossil fuels. Biodiesel is a promising fuel alternative to petroleum diesel because it offers economic and ecological benefits. It is produced from the transesterification or esterification of suitable oil feedstocks and catalysts. Commercial homogeneous catalysts face numerous obstacles, including product separation and soap formation due to the interaction between high-FFA feedstock with homogeneous base catalysts. Thus, biochar-based magnetic heterogeneous catalysts in biodiesel production have received attention from researchers due to their simple separation process, large surface area, and faster catalyst recovery. In addition, many researchers have explored using cosolvents with heterogeneous catalysts to enhance biodiesel yield by minimizing the phase resistance between oil and alcohol. This review investigates recent improvements in biochar-magnetic bifunctional heterogeneous catalysts for biodiesel production, focusing on their ability to integrate esterification and transesterification reactions in a single step. The influence of oil feedstock properties, cosolvents, and catalyst preparation methods on biodiesel yield is thoroughly examined. Furthermore, the role of biochar derived from waste materials in improving the performance of magnetic solid-acid and base catalysts is extensively investigated. The findings highlight the ability of these catalysts to streamline biodiesel production, overcome key challenges, and contribute to the development of more sustainable energy alternatives.FulltextenBiodieselBiochar magnetic heterogeneous catalystTransesterificationCosolventsArticleN/A