Techno-economic Assessment of the Production of Synthetic Jet Fuel by Electrolysis and Fischer-Tropsch Synthesis

Kurzfassung

Future aviation will continue to depend on energy carriers with a high energy density. The “Power-to-Fuel” technology is an approach to produce synthetic jet fuels from renewable energy (solar, wind). The German Aerospace Center investigates and evaluates the technical and economic performance of production processes based on these renewable energies and CO2. One process concept comprises the generation of H2 by water electrolysis from fluctuating renewable power sources. CO2 – e.g. sequestrated from industrial resources – reacts with H2 by the reverse water-gas-shift reaction to form syngas. Syngas is than synthesized to long chained hydrocarbons by the Fischer-Tropsch synthesis. The downstream product separation and upgrading section allows the production of gasoline, kerosene and diesel. A flowsheet simulation model of the proposed concept was set up and a pinch point analysis was conducted. The feed capacity was set to 1 GW(LHV) of H2 and offshore wind power was selected as the feedstock electricity. The process performance is evaluated by the Power-to-Fuel efficiency, which is the fraction of the total electrical energy input chemically bound into liquid hydrocarbons. A baseline Power-to-Fuel efficiency of 44 % was calculated. The carbon conversion was 73 %. The sensitivity of various operation conditions was analyzed. A Power-to-Fuel efficiency of up to 62 % was found, when a high temperature solid oxide electrolyzer is applied. The higher efficiency is obtained by the use of the process excess heat by the electrolyzer. For systems based on a stationary power input, production cost in the range from 5 $/GGE to 9 $/GGE were found. The production cost range from 12 $/GGE to 21 $/GGE when the system is powered by a renewable fluctuating energy source. The sensitivity of the full load hours, electrolyzer capital cost and electricity prices were analyzed and their effect on the production costs will be presented at the conference.