CO ₂ Capture and Utilization in Power Stations for Power-Heat-Methanol Polygeneration

This study presents a novel polygeneration configuration for simultaneous power, heat, and methanol generation, with integrated CO2 capture and utilization. The configuration builds upon a decarbonization power station, where captured high-purity CO2 is used as feedstock for methanol synthesis via CO2 hydrogenation. Furthermore, deep integration is implemented, enabling fully recoverable heat from both decarbonization and hydrogenation processes, to maximize overall thermo-economic performance. On the basis of a systematic retrofit of a typical 300 MW power station, thermodynamic assessment indicates that the proposed configuration converts coal (31.3 kg/s) and hydrogen (4.38 kmol/s) into 117.9 MW of power, 333.5 MW of heat, and 40.6 kg/s of methanol. Recoverable heat accounts for 66.6% of the total heat generation, while methanol conversion reaches 78.2%. Economic assessment shows that the gross cost of power generation (CPG) of the power section is increased from $38.8/MWh (reference) to $116.6/MWh, due to the decreased power generation and increased total investment. Nevertheless, the net CPG of the proposed configuration is reduced to $77.8/MWh, as the economic gains from the heating subsystem offset the gross CPG. By utilizing CO2 feedstock, power for gas compression, and heat for methanol distillation from the power station, the cost of methanol generation (CMG) of the methanol section is reduced from $1141.2/t (reference) to $1005.6/t, demonstrating strong economic competitiveness for industrial deployment.