Continuous operation of the potassium-based dry sorbent CO2 capture process with two fluidized-bed reactors

Abstract

The dry sorbent CO2 capture process is an advanced concept to efficiently remove CO2 from flue gas with two fluidized-bed reactors. This paper summarizes the results of performance of the two fluidized-bed reactors in the continuous solid circulation mode to investigate the feasibility of using potassium carbonate-based solid sorbent (Sorb KX35). The parameters such as gas velocity, solid circulation, carbonation temperature, and water vapor content were investigated during several continuous operations of two fluidized-bed reactors. The CO2 removal increased as gas velocity was decreased and as solid circulation rate was increased. The CO2 removal ranged from 26% to 73% was rather sensitive to the water vapor content among other parameters. A 20 h continuous operation conducted in a bench scale fast fluidized-bed reactor system indicated that the spray-dried potassium-based sorbent, Sorb KX35 having superior attrition resistance and high bulk density, had a promising CO2 removal capacity of 50-73% at steady state and was able to regenerate and reuse. The results from this work are good enough to prove the concept of the dry sorbent CO2 capture process to be one of viable methods for capturing CO2 from dilute flue gas of fossil fuel-fired power plants.