Review on second-generation synthetic fuel: feedstocks, potential production, deployable technologies, and challenges

ABSTRACTRecent advancements in energy conversion technologies have effectively addressed global challenges like fuel dependency, production costs, waste management, and pollution control. Utilizing natural waste to generate synthetic fuels represents a viable strategy for improved energy conservation, pollution mitigation, cost-effectiveness, sustainable production, and socio-economic development. Synthetic fuels are gaining global prominence as they reduce crude oil consumption, especially in the transportation and industrial sectors. This research meticulously reviews technologies available for synthesizing fuels from biological waste and enhancing feedstock quality. This study highlights the increasing adoption of algae as a feedstock for biofuel extraction via photobioreactors. Moreover, bioethanol and biobutanol can be derived from grasses through the lignocellulosic process. A pressing concern is the disposal of Municipal Solid Waste (MSW); however, biodiesel ester and biogas can be procured from MSW via transesterification and advanced gasification processes. While refined fuel production offers potential solutions to climate change and resource utilization challenges, specific issues persist. These include high production costs, significant power consumption, extended processing times, and inconsistent feedstock collection. Nonetheless, this study emphasizes the potential of advanced biofuel production from second-generation feedstocks. Such biofuels serve as promising carbon-based chemical sources for industrial and transportation applications, filling gaps left by conventional fuels.KEYWORDS: Synthetic fuelalcohol, Biodieselfeedstockmethanoltransesterification Nomenclature ASTM=American Society for Testing and MaterialsBTU=British Thermal UnitCaO=Calcium OxideCH4=MethaneCO2=Carbon DioxideCO=Carbon MonoxideCI=Compression IgnitionCNG=Compressed Natural GasDB=Diesel-Biodiesel blendFFA=Free Fatty AcidFT=Fischer-Tropsch fuelFAME=Fatty Acids and Methyl EstersH2=HydrogenH2O=WaterH2S=Hydrogen SulphideHCl=Hydrochloric acidH2SO4=Sulphuric AcidIC=Internal CombustionKOH=Potassium HydroxideLPG=Liquefied Petroleum GasMTBE=Methyl Tert-Butyl EtherNH3=AmmoniaNOx=Oxides of NitrogenNaOH=Sodium HydroxideNaOCH3=Sodium MethoxideOECD=Organization for Economic Cooperation and DevelopmentPAH=Polycyclic Aromatic HydrocarbonR&D=Research & DevelopmentDisclosure statementNo potential conflict of interest was reported by the author(s).Additional informationNotes on contributorsShobhit KhannaShobhit Khanna is working as a Senior Education Officer in defence, India and having 13 years of experience in designing and implementing effective training programs and curriculum for various academies that are not just academically rigorous but also attuned to the practical requirements of the real world. He has completed his Master’s degree in Thermal Engineering from IIT Madras. He is pursing Doctoral degree in the field of Mechanical Engineering from Amity University Madhya Pradesh, Gwalior, India. He has also been involved in various Projects, seminars/webinar and FDP programme, funded by Government of India.Rabindra PrasadDr. Rabindra Prasad is presently working as an Assistant Professor at Amity School of Engineering and Technology (ASET), Gwalior. He has completed his PhD in Mechanical Engineering from IIT (BHU) Varanasi and has published researc papers in journals of repute.C.P. JawaharDr. C. P. Jawahar is presently working as Professor and Dean, Faculty of Technology at Kalinga University,Raipur. His research areas includes renewable energy and thermal sciences. He is a Certified Energy Auditor by Bureau of Energy Efficiency, Ministry of Power, Government of India and has published 60 research papers in reputed international journals and conferences.Zafar SaidDr. Zafar Said is an Associate Professor with the Department of Sustainable Renewable Energy Engineering at the University of Sharjah. He works in the fields of Renewable Energy, Solar Energy, Heat Transfer, AI, optimization, Nanofluids, BTMS, NePCM, Energy Storage and nanolubricants. He has published over 250+ papers as per Web of Science, including in Progress in Energy and Combustion, Physics Reports, Advanced Energy Materials, Journal of Material Chemistry A, Nano Energy, Renewable and Sustainable Energy Reviews, 3 books, 30 book chapters, and 30 conference papers), with about 15100+ citations and an H-index of 71. As per Web of Science, he has 7 Hot Papers and several highly cited papers in the cycle 2019-2023. He is also ranked in World's Top 2% Scientists 2020, 2021, 2022, and 2023 by Elsevier BV and Stanford University) in the field of Energy. He was honored with several prestigious awards, including the 2022 Rising Star Science Star award by Research.com.