Green liquid fuel and synthetic natural gas production via CO2 hydrogenation combined with reverse water-gas-shift and Co-based Fischer-Tropsch synthesis

Abstract

In recent years, significant attention has been paid to the CO2 mitigation via the power-to-liquids (PTL) and power-to-gas (PTG) processes because they can efficiently transform CO2 into high-value products such as liquid hydrocarbons and synthetic natural gas (SNG), and provide a promising solution for the storage of the intermittent renewable energy. Herein, we suggested a PTL process and a PTL/PTG process combined with the reverse-water-gas-shift (RWGS) and Co-based Fischer-Tropsch synthesis (FTS), which respectively produce liquid hydrocarbons only and the combination of liquid hydrocarbons and high-calorie SNG, based on the previous study regarding the PTL and PTL/PTG processes composed of Fe-based FTS. We conducted the process modelling and comparative techno-economic analysis to determine the key performance of the proposed PTL and PTL/PTG processes including the CO2 mitigation rate, energy efficiency, total product cost and CO2 mitigation cost. The proposed PTL and PTL/PTG processes can be regarded as feasible technical solutions to convert wasted CO2 into high-value liquid hydrocarbons and SNG. Additionally, the indirect PTL and PTL/PTG processes were helpful for improving the production of liquid hydrocarbons. Meanwhile, the direct PTL/PTG processes and indirect PTL processes favor the energy efficiency and CO2 mitigation.