Investigation of Porous Silica Supported Mixed-Amine Sorbents for Post-Combustion CO2 Capture

Abstract

Prospective post-combustion CO2 capture sorbents were prepared by the immobilization of a low-molecular-weight, branched polyethyleneimine (PEI) and 3-(aminopropyl)triethoxysilane (APTES) within a commercially available porous PQ Corporation CS-2129 silica support to investigate (i) CO2 adsorption properties of the supported mixed-amine (PEI+APTES) sorbents in both pure CO2 environments and simulated flue gas conditions, (ii) their thermal and hydrolytic stability over numerous adsorption and desorption cycles, and (iii) their equilibrium and kinetic adsorption behavior. Initial CO2 adsorption–desorption measurements via thermogravimetric analysis (TGA) were conducted in pure CO2 to measure dry, near-equilibrium CO2 adsorption capacities, together in calculating amine efficiencies, which was recognized in being a meaningful criterion in evaluating sorbent performance for selecting the “most favorable” mixed-amine (PEI+APTES) composition. The as-prepared materials containing various weight ratios of PEI to...