(80b) Preparation of new organic-inorganic hybrid adsorbents for post-combustion CO2 capture

Recently, separation and sequestration of anthropogenic CO2 from power plant flue gas has been spotlighted due to the growing consensus on its effect on the global climate change. Among several known strategies to remove CO2 from the flue gase, adsorption processes by solid adsorbents have been widely studied. With a particular interest in this approach, we have focused on the potential of hyperbranched aminosilica (HAS) materials as sorbents. This inorganic-organic hybrid material was prepared by ring-opening polymerization of aziridine on mesoporous SBA-15 silica, thereby directly while incorporating aminopolymers onto the silica support. High amine content in the first generation HAS adsorbent lead to a high adsorption capacity of CO2 up to 3.1 mmol/g at 25 °C in the presence of humidified, simulated flue gas, along with adequate regenerability. Following these initial efforts, these novel material have been more deeply characterized with the aim of understanding and improving its CO2 capture ability. This talk will present assessment of the CO2 adsorption capacity of the HAS material as a function of the operating temperature, organic loading, polymer molecular weight, the ratio of 1°:2°:3° amines, and other factors. Experimental conditions such as the reaction temperature and solvents used during synthesis were modified to evaluate an effect of these variables on the composition and structure of the HAS sorbent. Based on these data, we present optimized synthesis methods that enhance the equilibrium capacity of CO2 using the HAS hybrids.