Amine-functionalized mesoporous monolithic adsorbents for post-combustion carbon dioxide capture

Abstract Amine-functionalized solid adsorbents have significant application potential in post-combustion CO2 capture due to the advantages of high capacity, low regeneration cost and long-term stability. Although the powdery adsorbents exhibit higher CO2 uptake capacity, the poor strength and large pressure drop limit their practicability. Monolithic adsorbent is considered as a good choice to solve these problems, but still facing the bottle-neck of insufficient CO2 capacity. In this work, a facile and feasible gel-casting method was proposed to fabricate monolithic adsorbents with high CO2 capacity, excellent mechanical strength, and good cycling stability. MCM-41 with rich mesoporous structure was immobilized by polymerization of organic polymer to construct monolithic adsorbents supports with high specific surface area (∼1088 m2 g-1) and mechanical strength. The 70T-MM-550 monolithic adsorbent impregnated with TEPA achieved high adsorption capacity of 151.1 mg g-1 at 75 ℃ under 1 atm pure CO2. The monolithic adsorbents also showed good reversibility of CO2 adsorption under mild conditions, where the adsorption capacity decreased only by 2.8% after five regeneration cycles. In addition, the radial and axial compressive strength of 70T-MM-550 is over 200 N cm-1 and 4.5 MPa, respectively. In consideration of the high CO2 capture performance and mechanical properties of the monolithic adsorbents, the findings here open a new avenue for designing efficient monolithic CO2 adsorbents with industrially potential.