Process Simulation, Integration and Energy Analysis of Direct Air Capture and Green Fischer–Tropsch Fuel Production

Direct Air Capture (DAC) technology provides a promising way for extracting carbon dioxide (CO2) directly from the atmosphere, enabling its use in either long-term sequestration or as a carbon source for synthetic green fuel production. In this study, CO2 captured via DAC is combined with green hydrogen (H2) to synthesize gasoline, targeting decarbonization of the transportation sector. To maximize system efficiency, a process integration strategy is employed. Tail gas and by-product oxygen from the electrolysis unit are recycled in the Allam cycle, a high-efficiency oxy-fuel combustion system, and in a Rankine cycle (RC) to generate electricity. The integration enhances both mass and energy utilization, boosting overall process performance. The process is modelled and integrated to evaluate its energy performance. Energy analysis of the green Fischer–Tropsch (FT) fuel pathway highlights the potential of DAC-based synthetic fuels as a solution for reducing CO2 emissions.