Overview on catalyst and co-solvents for sustainable biodiesel production

Globally there is a quantum rise in production of biodiesel due to its ability to mitigate greenhouse gases. However, the production of biodiesel faces a major hurdle in obtaining high purity and easy separation of the main product from glycerol. Researchers worldwide are focusing on finding new sophisticated materials that may help to develop a sustainable eco-efficient process. Only a limited number of review articles have been published that cover the use of a catalyst and co-solvent for easy separation of biodiesel from glycerol. In this paper, assessment of various catalysts (homogeneous and heterogeneous), ionic liquids and deep eutectic solvents (green solvents) for biodiesel production is reviewed. This will help researchers to find an excellent combination and economic feasibility for biodiesel manufacturing meeting environmental standards. This will provide a solid background for future research.