Renewable methanol synthesis from renewable H₂ and captured CO₂: How can power-to-liquid technology be economically feasible?

With the growing concern about environmental issues including high CO₂ emission, which is the main contributor to global warming resulting in climate change, CO₂ utilization technologies have received much attention. Among diverse technologies, renewable methanol synthesis using H₂ generated from the water electrolysis and the CO₂ captured from various industrial processes as well as the atmosphere has received significant attention. In this context, the technical and economic feasibility analysis of renewable methanol synthesis was conducted in this study. Using a commercial process simulation program, Aspen HYSYS®, parametric studies were conducted to investigate the effects of diverse operating parameters, such as the reaction pressure, temperature, and H₂/CO₂ ratio, on the technical performance of this process. Under the optimum conditions of 100 bar and 493 K derived from thermodynamic studies, an economic analysis was performed to estimate the unit methanol production costs at different methanol production capacities using itemized cost estimation, sensitivity analysis, and predictive cost analysis. Predictive cost analysis was conducted to determine how the unit methanol production cost could be rendered reasonable compared to the existing one, which indicated that decreasing the renewable H₂ production cost as well as increasing in the CO₂ tax credit for a methanol production capacity of 100 ton per day would make the renewable methanol synthesis an economically feasible process.