What e-fuels are and their production steps
E-fuels, or electrofuels, are synthetic fuels produced by combining hydrogen (typically from electrolysis) with captured carbon dioxide or carbon monoxide. They are designed to mimic conventional liquid or gaseous fuels but are manufactured using low-carbon electricity and captured carbon, reducing lifecycle emissions when produced sustainably.
Basic production pathway
- Hydrogen production: water electrolysis using renewable electricity produces low-carbon hydrogen.
- CO2 sourcing: CO2 is obtained from point-source capture, direct air capture, or industrial waste streams.
- Synthesis: hydrogen and CO2 are converted into hydrocarbons through catalytic processes such as Fischer-Tropsch synthesis, methanol synthesis, or methanation.
- Refining and shaping: the synthetic hydrocarbons are processed into fuels like synthetic gasoline, diesel, jet fuel, or methane for specific end uses.
Common e-fuels
- E-diesel and e-gasoline: liquid hydrocarbons that can often be used in existing internal combustion engines with little or no modification.
- E-kerosene: synthetic jet fuel that can replace fossil jet fuel for aviation.
- Synthetic methane: compatible with natural gas systems or for power generation.
Benefits and challenges
- Benefits: compatibility with existing transport infrastructure and engines, potential for deep emissions cuts when produced with renewable energy and low-carbon CO2.
- Challenges: high energy input per unit of fuel, dependence on abundant low-cost renewable electricity and low-carbon hydrogen, and currently higher costs than fossil fuels.
Best-fit applications
E-fuels are especially promising for sectors where batteries or direct electrification are impractical—such as long-haul aviation, shipping, and some heavy transport—because they offer high energy density and the ability to use existing fuel logistics.
Conclusion
E-fuels replicate conventional fuels but are produced from renewable electricity and captured carbon. They offer a pathway for decarbonizing hard-to-electrify sectors, although cost and energy requirements mean they are likely to be targeted to specific high-value uses as deployment scales.