Development of strategies for the regeneration of polyethylenimine based CO2 adsorbents

Adsorption is considered to be one of the more promising technologies for capturing CO2 from flue gases. It has been demonstrated that amine polymers, such as polyethylenimine, immobilised on variable porous substrates, silica, zeolites and fly ash, are effective adsorbents for CO2. The ease of regeneration and the lifetime of the adsorbents are critical factors in determining the efficiency and therefore feasibility for use as CO2 capture technologies. In this paper two approaches, thermal swing desorption over a range of temperatures and time in an atmosphere of CO2 and thermally assisted pressure swing desorption, are explored for the regeneration of the PEI based adsorbents. The advantages and disadvantages, for example irreversible carbamate formation, will be described for both regeneration techniques with conclusions drawn to their feasibility and influence on adsorbent lifetime.