Modeling the carbonator of a Ca-looping process for CO2 capture from power plant flue gas

The calcium-looping process is a promising technique for CO2 capture from coal-fired power plants and for reducing GHG emissions from the power generation sector. This paper presents a calculation model of the carbonator, the key reactor of the Ca-looping process, where CO2 is captured as a result of its reaction with CaO. The model presented is based on the Kunii–Levenspiel theory for circulating fluidized bed and on the recent findings on the properties of CaO as a CO2 sorbent, while taking into account the effects of coal ash and sulfur species.This model can be used for process optimization and for the prediction of the performance of power plants based on the Ca-looping process. Also presented in this paper are the results of a sensitivity analysis of the primary parameters that influence the performance of the carbonator. These results confirm the feasibility of the Ca-looping process with reactors of reasonable size for industrial applications and highlight the importance of the properties of the Ca-based sorbent as they highly affect the carbonator's performance.

► New model of a carbonator reactor for CO2 capture from combustion flue gas.
► Effects of coal ash and sulfur species included.
► Effects of main operating parameters on CO2 capture efficiency assessed.
► Important effects of parameters describing sorbent properties quantified.
► Simplified methodology for preliminary fast calculation described.