PhD Advisor:  Professor James W. G. Turner

Abstract:
Decarbonizing transport fuels requires pathways that reduce life-cycle greenhouse gas emissions while remaining compatible with existing internal combustion engine infrastructure. Ethanol and methanol are promising low-carbon fuels due to their high knock resistance and clean-burning potential, but conventional production routes often vent biogenic CO2 and underuse agricultural residues, limiting overall carbon utilization. This thesis develops a circular bio-e-fuel pathway that integrates biomass fermentation, residue gasification, and CO2 hydrogenation with low-carbon electrolytic H2 to produce hydrous ethanol, bio-e-methanol, and e-methanol while maximizing biogenic carbon utilization.

A unified Aspen Plus model was developed to quantify mass and energy flows and provide harmonized inputs for well-to-tank life-cycle assessment (WTT-LCA) and techno-economic analysis (TEA). The pathway was evaluated for sugar cane in Brazil, sugar beet in France, corn in the United States, and date palm in Saudi Arabia, reflecting region-specific biomass availability, electricity systems, and policy contexts. WTT-LCA was used to assess climate and midpoint impacts under different electricity scenarios, while TEA examined levelized costs, profitability, and key economic uncertainties. CFR engine testing of hydrous ethanol–methanol blends derived from the process models was also conducted to connect fuel production performance with real-world combustion and emissions. Overall, the thesis provides a region-specific framework for comparing circular e-fuel pathways across process feasibility, environmental performance, economic viability, and end-use engine behavior.

Bio:
Renston Jake Fernandes is a Ph.D. candidate in Environmental Science and Engineering at King Abdullah University of Science and Technology (KAUST) in Saudi Arabia, affiliated with the Clean Energy Research Platform (CERP). His research focuses on circular carbon fuels, clean combustion, and the techno-economic and environmental assessment of sustainable fuel pathways. His work has also explored integrated pathways for producing e-methanol from Saudi Arabian biomass resources, particularly date palm fruit and waste, by combining process modelling, life cycle assessment, and techno-economic analysis to support low-carbon fuel strategies in the region.