A Review of the Emission, Performance, Combustion, and Optimization Parameters in the Production of Biodiesel from Waste Cooking Oil

With the rising consumption of energy comes the challenge of the depletion of fossil fuels. Fossil fuels are non-renewable and finite energy sources with increasing energy demand as a result of the rise in human population and industrialization. This concern has led researchers to seek alternative energy sources that are both economically, technically viable, and environmentally beneficial. Biodiesel is considered an alternative source of energy supply. It is non-toxic, biodegradable, carbon-neutral, and ecologically friendly. However, the high cost of producing biodiesel from feedstocks impedes its commercialization. Hence, WCO used in the production of biodiesel helps to reduce the overall cost of production. The characteristics of the performance, emission, and combustion of the biodiesel produced from the transesterification of WCO are reviewed in this study.  The molar ratio of methanol to oil, the concentration of the catalyst, reaction temperature, and time were used to investigate the optimization parameter required in the synthesis of biodiesel from WCO. The number of times the catalyst can be reused while maintaining a good catalytic activity in biodiesel production was also studied. The optimization models and techniques for the prediction of biodiesel yield were also studied.