Progress and facts on biodiesel generations, production methods, influencing factors, and reactors: A comprehensive review from 2000 to 2023

• Published in: Energy conversion and management 2024-02, Vol.302, p.118157, Article 118157
• Main Authors: Singh, Narender, Saluja, Rajesh Kumar, Rao, H. Jeevan, Kaushal, Rajneesh, Gahlot, Neeraj Kumar, Suyambulingam, Indran, Sanjay, M.R., Divakaran, Divya, Siengchin, Suchart
• Format: Article
• Language: English
• Subjects: Biodiesel yield; Microreactor; Renewable energy; Supercritical process; Transesterification; Ultrasonication
• ISSN: 0196-8904; 1879-2227
• DOI: 10.1016/j.enconman.2024.118157

[Display omitted] •Biodiesel's Generational Evolution: 2000–2022.•Progress in Sustainable Biodiesel Production Methods.•Influencing Factors Explored: Policies to Feedstocks.•Diverse Feedstock Sources Enabling Efficiency.•Reactor Technologies Shaping Biodiesel's Future. In response to the increasing demand for diesel fuel and its shortage, biodiesel has emerged as a potential alternative. This review thoroughly examines the physicochemical characteristics of biodiesel from several generations using a variety of feedstocks. The study reveals that biodiesel with low concentrations of polyunsaturated fatty acid methyl esters (FAME) and long-chain saturated FAME exhibits favorable characteristics, including improved performance, oxidation stability, and operability at low temperatures. Many technologies have been used to produce biodiesel, but the transesterification process has proven to be the most cost-effective and efficient approach, producing the maximum amount of biodiesel, making it the technique of choice for commercial bio-production. The paper presents an in-depth examination of biodiesel production methods, explaining production patterns influenced by elements such as reactant mass transfer restrictions, feasibility in upstream processes, and downstream processing ease. Furthermore, third generation feedstocks, especially algae-based sources, outperform their predecessors due to their higher energy content, significant oil content, and ecologically harmless characteristics. The article additionally covers a variety of catalysts, including ionic liquid catalysts, enzyme catalysts, nano catalysts, and heterogeneous and homogeneous acid/base catalysts. Following a detailed evaluation of various reactor designs, the research concludes that using a supercritical method has tremendous promise for biodiesel synthesis. This comprehensive overview not only examines the benefits and drawbacks of various biodiesel production methods, but it also contributes to a better understanding of the factors influencing biodiesel production trends, thereby encouraging the development of sustainable and efficient biodiesel technologies.