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.Copyright © 2005 by ASME