(484f) Synthesis and Characteristics of Amine Functionalized Biopolymers for CO2 Capture

The increase in the atmospheric concentration of CO₂ is considered as one of the major causes of global warming. Separation and recovery of CO₂ from large CO₂ emission point source have been investigated. Recently, there are many reports on amine loaded mesoporous silicas having high CO₂ adsorption capacity. However, toxic and expensive chemicals are used to synthesize mesoporous silicas. Additionally, most reports on amine loaded mesoporous silicas discuss the CO₂ adsorption characteristics for “powder” form mesoporous silicas. Mesoporous silicas seem to be less reliable now because the adsorbent must be in the form of bead, granule or pellet to use in actual CO₂recovery processes. Therefore, alternative adsorbent “beads” made from low-cost and eco-friendly chemicals should be developed.

In this study, highly porous amine functionalized biopolymer beads were synthesized and CO₂ adsorption performance was evaluated. As a result, it was found that the polyethyleneimine functionalized beads had high CO₂ adsorption capacity with high adsorption rate. The CO₂ adsorption capacity reached 2.3 mmol/g in the absence of water vapor and 3.6 mmol/g in the presence of water vapor at 313 K and 15 kPa of CO₂.

In general, amine impregnated materials show high CO₂ adsorption capacities but lower adosorption rate. On the other hand, amine grafted materials have the advantage of physical and chemical stability of loaded amines, high amine efficiency and adsorption-desorption rate. The adsorption characteristics of our material show advantages of both amine impregnated and grafted materials, i.e., relatively high adsorption capacity and fast adsorption rate. The results suggest that this material has potential for effective CO₂ adsorbent.