Turning CO2 from fuel combustion into e-Fuel? Consider alternative pathways

Abstract

Carbon capture and utilisation technologies for the separation and conversion of CO2 into chemical products via electrochemical processes (i.e., so called electro-fuels/e-Fuels, or electro-chemicals/e-Chemicals) are envisaged to be an option in the forthcoming decarbonisation of energy and industry, but their effectiveness in terms of carbon emissions avoidance is debated. This work challenges the exploitation of CO2 from fuel combustion for the synthesis of e-Fuels, as opposed to alternative pathways. The investigated conversion routes refer to a case study for the abatement of CO2 emissions from a refinery fuel gas via production of synthetic fuels based on: (i) hydrogenation of CO2 with green H2 (i.e., e-Fuel); or (ii) electrified heating and electrified reforming of the fuel gas. For both options, two products are compared: methanol and Fischer–Tropsch syncrude. The study shows that avoiding CO2 emissions by turning CO2 from fuel combustion into an e-Fuel results in higher electricity demand, higher capital costs, and higher fuel costs than the electrification of heat supply and the direct conversion of the original fuel into a higher value synthetic fuel via electrified reforming.