Net-Zero Propulsion and Supply-Chains Management of Sustainable Aviation Fuels Towards Delivering a Green Aviation

<p dir="ltr">1st year PhD confirmation review report:</p><p dir="ltr">Sustainable aviation fuel (SAF) research is essential for decarbonizing aviation by improving fuel production, combustion efficiency, scalability, and reducing costs. The main aim of this research is to investigate lean flammability limits and to conduct lifecycle assessment (LCA) on the most technologically significant SAF supply-chains. The proposed research aims to address the main gaps identified in the literature review on lean blowout (LBO) and SAF supply-chain management.</p><p dir="ltr">The LBO behaviour of several fuels, including SAF and SAF surrogates, will be experimentally studied using a bluff-body stabilized swirl spray burner and optical diagnostics. As SAF are a new technology, this research will yield completely novel results and provide data for computational models. The effect of secondary dilution air will be explored to investigate the potential of enabling stable combustion under leaner conditions, improving fuel efficiency. Preliminary results on LBO of ethanol with secondary dilution air showed a correlation between dilution air and increased flammability limits. To explore this further, diagnostic techniques and additional tests will be conducted to evaluate the effects on other identified fuels.</p><p dir="ltr">LCA will be carried out on identified SAF feedstock supply chains and conversion processes. This research will provide a new comprehensive analysis using location specific data, covering direct and indirect environmental effects. Cradle-to-cradle LCA will be performed, incorporating models for soil carbon flows, combustion, and the utilization of byproducts. A prospective LCA will be conducted, considering future improvements in feedstock production, SAF conversion, and combustion performance. Since no significant cradle-to-cradle or prospective LCAs exist for SAF, this research will offer a novel analysis. Preliminary LCA results of fast pyrolysis using corn stover showed a 57% reduction in global warming potential compared to fossil based aviation fuel, with further reductions when wind energy was used. Scenarios involving green hydrogen and carbon capture will also be explored.</p><p dir="ltr">Multi-criteria decision analysis (MCDA) will be carried out using a novel combination of methodologies, weighting distributions, and criteria with the aim of aiding stakeholder decision-making and reducing bias through mathematical validation.</p>