Perspectives of oxy-coal power plants equipped with CO2 capture, utilization, and storage in terms of energy, economic, and environmental impacts
Semie Kim, Young‐Il Lim, Doyeon Lee, Won Chul Cho, Myung Won Seo, Jae Goo Lee, Yong Sik Ok
Abstract
CO 2 -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 CO 2 capture, water electrolysis, and CO 2 methanation on electricity efficiency, CO 2 emission rate, CO 2 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 CO 2 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 CO 2 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 CO 2 emission sources.