Techno-Economic Analysis (TEA) of Civilian Sustainable Aviation Fuel (SAF) – A systematic review of Hydrotreated Esters and Fatty Acids (HEFA) and Lignocellulosic Biomass Conversion (LCBC) Strategies

This comprehensive review synthesizes current research to systematically evaluate the viability of Hydroprocessed Esters and Fatty Acids (HEFA) and Lignocellulosic Biomass Conversion (LCBC) pathways for sustainable aviation fuel (SAF) production, with additional comparison to emerging battery-electric propulsion systems. The analysis reveals that most techno-economic assessments disproportionately emphasize capital investment and feedstock costs, while critically underrepresenting transportation logistics and co-product valorization – factors shown here to reduce minimum selling price (MFSP) by up to 67 %. Statistical analysis (χ2 = 141.6, p < 0.0001) confirms this research bias. Yield optimization emerges as an effective strategy for lowering MFSP, surpassing plant capacity expansion, with HEFA pathways achieving higher average SAF yields (62 % vs. 57 % for LCBC) and superior energy efficiency (as low as 19.6 kWh/MT feedstock/h for HEFA compared to up to 620.7 kWh/MT for LCBC). However, LCBC offers greater carbon neutrality, achieving up to 94 % greenhouse gas reduction and lower lifecycle emissions. The review introduces a comprehensive efficiency metric that incorporates all significant energy inputs – including hydrogen, natural gas, steam, and indirect energy for feedstock logistics – as well as greenhouse gas emissions, providing a more accurate assessment of process and environmental performance. Catalyst innovation and policy incentives are identified as decisive levers, with the potential to reduce SAF production costs by up to 26 % and increase project profitability by over 50 % respectively. These findings establish a robust framework for SAF pathway assessment and optimization, highlighting the need for future research and policy to prioritize advanced feedstock processing, supply chain optimization, co-product valorization, and integrated techno-economic and sustainability modeling to accelerate the deployment of cost-competitive, scalable SAFs and support aviation industry's decarbonization goals.