Enviro-economic assessment of sustainable aviation fuel production from direct CO2 hydrogenation

The aviation industry is responsible for 2% of the total GHG emissions and 10% of the fuel consumption worldwide and sustainable aviation fuel (SAF) is considered a key step towards achieving net-zero aviation. In this work, we carry out an enviro-economic comparison of a one-step Fischer-Tropsch process (1sFT), based on a novel Mn-Fe-K catalyst, whereby CO2 and H2 are directly converted to liquid hydrocarbons, with a two-steps FT process (2sFT), in which a reverse water gas shift reactor is used to produce syngas, followed by a conventional FT process. 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 end-point environmental impacts. Our results suggest that the fuel blend from 1sFT has a minimum selling price 20% lower than the fuel blend from 2sFT, due to a lower capital cost and a higher selectivity towards liquid hydrocarbons. 1sFT is also found to be superior to 2sFT from an environmental point of view, with 30% lower GWP and 70% lower externalities cost.