Alternative pathways to sustainable aviation fuel from CO2 and H2: an enviro-economic assessment

With air transportation responsible for 2% of the total GHG emissions and 10% of the fuel consumption worldwide, sustainable aviation fuel (SAF) is considered a key enabler to reach net-zero aviation by 2050. In this work, we carry out an enviro-economic comparison between a one-step Fischer-Tropsch process (1sFT) and a methanol-to-jet process (MTJ). 1sFT is based on a novel Mn-Fe-K catalyst promoting direct conversion of CO2 and H2 to liquid hydrocarbons. In MTJ, methanol is produced first, followed by methanol-to-olefin conversion, oligomerization, and hydro-processing. Our analysis considers 1 MJ of liquid fuel as functional unit and the following key performance indicators: levelized cost of production, global warming potential, and monetized endpoint environmental impacts. Our results suggest that 1sFT outperforms MTJ by 23-36%, depending on H2 and CO2 costs. 1sFT is also found to be superior to MTJ from an environmental point of view, with up to 33% reduction in GWP and 28% reduction in monetized environmental externalities on a well-to-wake basis.