Perspectives of oxy-coal power plants equipped with CO₂ capture, utilization, and storage in terms of energy, economic, and environmental impacts

CO₂-free power plants (PPs) with renewable electricity have promising sustainability implications, but the impact of their widespread use is yet to be determined. Here, the effect of an oxy-coal PP equipped with CO₂ capture, water electrolysis, and CO₂ methanation on electricity efficiency, CO₂ emission rate, CO₂ capture cost, and global surface temperatures (T_g) was investigated. By exploiting surplus electricity from renewable sources for electrolysis, we estimated that 5 % of the CO₂ emitted from the coal PP was methanized. The process flow diagram of a 500 MW_e decarbonized oxy-coal PP was constructed and its impact on energetic, economic, and environmental values was evaluated. The results were applied to a model of the global carbon cycle to predict T_g considering the prospective global population and carbon emission rate (r_ff) of fossil fuels by 2050. An 80 % replacement of conventional coal PPs worldwide by decarbonized oxy-coal PPs contributed to reducing r_ff by 6.1 Gt_CO2/y in 2050 and lowering T_g by 0.09 °C. The additional capital cost to replace 80 % of conventional coal PPs with decarbonized oxy-coal PPs, including associated geological storage costs, was estimated to be $43/t_CO2. This study elucidates the promise and limitations of coal PPs designed for CO₂ capture, utilization, and storage (CCUS). Combining CCUS technologies with global warming estimates can be extended to examine the economic and climatic impact of CCUS under various CO₂ emission sources.