Steam Regeneration of Amine Impregnated Silica Based Sorbents for Post Combustion CO2 Capture

Abstract

In this study, an experimental investigation of CO2 capture using amine functionalized mesoporous silica based sorbents was carried out. Polyethyleneimine (PEI) impregnated silica sorbents were synthesized and tested in TGA under different adsorption temperatures and partial pressures of CO2. Sorbent characterization was carried out using N2 adsorption-desorption isotherms, FTIR, SEM and elemental analysis. Multiple cycles study was conducted to examine the effect of presence of O2 (0-5%) in flue gas on CO2 adsorption performance of sorbent. A separate packed bed study was conducted to study the effect of different concentrations of moisture (5.27–14.74%) in flue gas on CO2 adsorption and energy requirements for sorbent regeneration. A major study that was undertaken was to test the performance and stability of sorbent under steam stripping conditions. Steam was used for sorbent regeneration in a multiple cycle study and characterization of used sample was carried out to study any change in sorbent properties. Steam at different temperatures was used to study CO2 desorption. Desorption kinetics for steam and inert gas stripping was compared. It was observed that the sorbent performance was stable under steam environment along with improved desorption kinetics over inert gas stripping. No steam condensation or amine leaching was observed in this study.