(701f) CO2-to-Sustainable Synthetic Fuel Process: Scenario-Based Techno-Economic and Carbon Footprint Analysis

Carbon dioxide can be efficiently utilized through liquid hydrocarbons as an energy carrier, making it a viable solution for transitioning from a linear carbon flow to a circular one. Synthetic fuel is crucial due to challenges in decarbonizing the sector, such as aviation transport, and ensuring fuel production regardless of infrastructure availability.

This work discusses the sustainable synthetic fuel (SSF) production system, considering various aspects, including technical readiness, energy, economics, carbon intensity, and carbon footprint. A conceptual process flow was developed by integrating mature and promising chemical operational units. The Fischer-Tropsch-based synfuel-making route was studied by incorporating different types of electrolyzers. The first process was designed by the proton exchange membrane electrolysis cell (PEMCE) to produce hydrogen, which was technically viable. The second process was designed by the high-temperature solid oxide electrolysis cell (SOEC) to coproduce hydrogen and carbon monoxide, which can replace the water-gas shift reactor. After deriving the process flowsheet, multiple scenarios for SSF production were illustrated by comparing carbon footprint analysis results based on energy origin. The study parametrically investigated factors such as the cost of electricity and natural gas, scale of CO₂ utilization, origin of the captured CO₂, and internal recycling flow. Through the work, we revealed the bottlenecks of the SAF-making process to be economically viable and environmentally benign.