Evaluation and improvements on the flexibility and economic performance of a thermal power plant while applying carbon capture, utilization & storage

Abstract

To investigate the impact of carbon capture, utilization & storage (CCUS) on thermal power plants' flexibility and economic performance and provide feasible solutions, an analysis was conducted based on a typical 630 MW thermal power plant and a provincial thermal power installation. Taking the 630 MW coal-fired power plant as an example, solar-assisted and low-pressure turbine (LPT) zero-output schemes were proposed to enhance the flexibility of the plant. Additionally, economic sensitivity analysis was carried out for the CCUS-enhance oil recovery (EOR) process, followed by the proposal of the CO2-to-methanol pathway in a province located in northwest China. The results showed that the power output space after applying a carbon capture unit scheme was reduced from 178 to 619 MW to 311–439 MW, but this was restored to 92.97 MW-560.89 MW by using the two proposed performance enhancement schemes, thereby significantly improving the flexibility of the plant. Under the conventional CCUS-EOR pathway, the electricity price increased by approximately 12.59 $/MWh-15.65 $/MWh. However, if the CO2-to-methanol pathway were adopted, the most economically beneficial scheme would achieve a mere 0.54 $/MWh, leading to almost zero-cost decarbonization of thermal power plants.