Recent advances on biodiesel production from waste cooking oil (WCO): A review of reactors, catalysts, and optimization techniques impacting the production

The continued economic growth registered since the 1970 s has contributed to an increase in the demand and supply of energy in the main end-use sectors: electricity, heating, cooling, and transportation. This has instigated the search for alternative energy sources with less carbon footprint than that of fossil fuels. In the transportation sector, biodiesel has been reported as a promising alternative to conventional fuels. However, despite its widespread commercialization, cost of biodiesel feedstocks is still a significant problem. This paper reviews the utilization of waste cooking oil as a feedstock for biodiesel production using transesterification, in addition to pathways to increase the quality and efficiency of biodiesel production and decrease its production costs. We have explored pertinent topics such as reactor types, catalysts, other parameters affecting biodiesel production, as well as vital optimization techniques that can be utilized to enhance biodiesel production from waste cooking oil. Finally, we have attempted to present the existing gaps and future challenges in this field, which when circumvented could make this longstanding process more economically viable.