Performance Prediction of High-Temperature CO₂ Capture System Utilizing Lithium Silicate for Pulverized Coal-Fired Power Plant

Lithium silicate is a solid CO₂-sorbent that can be used repeatedly, and uniquely features absorption of CO₂ at temperatures between 500°C and 600°C with an exothermic reaction and regeneration at temperatures above 700°C with an endothermic reaction. This paper introduces the conceptual model and feasibility study of the CO₂ capture system utilizing the lithium silicate applicable to a pulverized coal-fired power plant. In this system, assuming a moving bed, the sorbent reactor is installed in a 500MW boiler and absorbs CO₂ in the flue gas, and after the absorption process, recirculation of CO₂ transports the heat for regeneration. To design the system, unsteady state numerical analysis was used to predict the reactor performance in a 60-minute cycle for absorption and regeneration, which includes the reaction rate based on experimental data. The analysis result indicates that about 20% of CO₂ can be captured from flue gas without significant loss in the power generation efficiency.