Experimental Characterization and Mechanistic Simulation of CO2 Adsorption/Desorption Processes for Potassium Promoted Hydrotalcites Sorbent

Abstract

The elevated temperature pressure swing adsorption (PSA) based on potassium promoted hydrotalcite-like compounds (K-HTlc) is one of the most promising technologies for pre-combustion CO2 capture. K-HTlc could achieve a fast part of reversible CO2 capacity under desorption conditions of low inert purge flow rate and short purge time. The CO2 breakthrough capacity is 1.01 mmol/g and 0.6 mmol/g at 1.2 MPa (CO2 partial pressure) for 400 o C and 300 o C, respectively. A one-dimensional isotherm column model was developed to describe the K-HTlc performance and CO2 transportation in a single column during PSA process. The results indicated that the simulation results agreed well with the experimental results. The CO2 desorption process of K-HTlc should be characterized as a fast and a followed slow process which is origin from the chemisorption characteristics and was validated by the model results. The presented model could be further applied in the practical industrial PSA.