Efficient solar hydrocarbon fuel production by integrating Fischer-Tropsch synthesis with high-temperature solid oxide co-electrolysis and electrolysis

Solar production of syngas from water and carbon dioxide followed by solar-driven Fischer-Tropsch synthesis is promising technology to produce syngas with zero carbon emission. A solar-driven integrated system by coupling solid oxide electrolysis cells with Fischer-Tropsch process is proposed for green hydrocarbons production. The proposed system is numerically modeled, developed and verified in this study. The effect of the solid oxide electrolysis cell temperature and current density on the system performance, especially the solar-to-fuels efficiency, is investigated parametrically. The results show that the solar-to-fuels efficiency increases with rise in the solid oxide electrolysis cell temperature. In addition, there is an optimum solar-to-fuels efficiency by varying current density. A maximum solar-to-fuels efficiency of 12.8% is obtained, which is more than 2.82% higher than the benchmark efficiency of solar hydrocarbons production system utilizing high-temperature co-electrolysis only. Moreover, a preliminary techno-economic analysis is performed to investigate the techno-economic feasibility of the proposed system. Based on the analysis, the levelized cost of the fuel for the proposed system is 1.944 Euro/kg. This study does not only verify the thermodynamic feasibility of the system but also provides a baseline for further optimization.