Thermodynamics, economic and carbon emission analysis of power-to-methanol process through alkaline electrolysis and monoethanolamine (MEA) carbon capture

The integration of renewable power for hydrogen production, carbon capture, and methanol synthesis process presents a novel approach to produce green methanol and promote renewable energy utilization. There are few studies on full process modeling, and the impact of CO₂ boundaries on carbon emissions and levelized costs has not been thoroughly analyzed. A complete modeling of the renewable power-to-methanol process was conducted in this work, considering energy, exergy, economy, and the environment perspectives. Thermodynamic and economic models were established, and a life cycle assessment model was conducted to evaluate the CO₂ emissions. The renewable power-to-methanol process achieved energy and exergy efficiencies of 36% and 30%, respectively. The methanol levelized cost is 840.50 $/ton. The main factor affecting the levelized cost is the price of renewable energy. Different CO₂ calculation boundaries lead to opposite carbon emissions results.