Polyetheramine improves the CO2 adsorption behavior of tetraethylenepentamine-functionalized sorbents

Abstract

To accomplish efficient CO2 capture from coal-fired power plants, the polyetheramine of poly(propylene glycol)bis(2-aminopropyl ether) (A), with high electron cloud density, was codispersed with tetraethylenepentamine (TEPA) to prepare solid amine sorbents. The effects of the mass ratio of TEPA to A and adsorption temperature, as well as CO2 adsorption isotherms, were investigated. The regeneration, adsorption and desorption kinetics for TEPA-functionalized MCM-41 before and after A codispersion were also studied. A improved the adsorption performance of TEPA-functionalized MCM-41 not only at 60 °C, but also at lower temperatures. When the mass ratio of TEPA to A was 50% to 10%, the breakthrough time and equilibrium adsorption capacity were 14 min and 3.58 mmol/g, respectively, at 30 °C, and 12 min and 3.09 mmol/g, respectively, at 60 °C, values that are significantly better than the values for TEPA-functionalized MCM-41. The adsorption heat of co-functionalized MCM-41 was approximately 11–13 kJ/mol in the temperature range of 30–50 °C, showing a typical physisorption characteristic. In addition, CO2-TPD results indicated that co-functionalized sorbent showed faster desorption rate and lower regeneration energy consumption. After ten regenerations, the equilibrium adsorption capacity was 2.93 mmol/g, representing 94.8% of the fresh sorbent capacity.