Synthesis of porous polymer based solid amine adsorbent: Effect of pore size and amine loading on CO adsorption.

A series of porous polymers was synthesized by a suspension polymerization of divinylbenzene (DVB) and ethylene glycol dimethyl acrylate (EGDMA), which was further functionalized with polyethyleneimine (PEI) for CO capture. The results showed that the synthesized DVB and EGDMA (DE) copolymers were an effective support for loading PEI because of its larger pore size and specific surfaces area. It was found that DE (30, 10) loaded with 30wt% PEI exhibited a higher CO adsorption amount of 3.28mmol/g at 25°C under dry condition. The CO adsorption capacity would decline gradually as the temperature continuously raised, for the reaction between CO and amine groups was an exothermic reaction. The kinetics study showed that Avrami kinetic model could accurately describe the whole CO adsorption process, suggesting that both physical adsorption and chemical adsorption were involved with the CO adsorption process. The intraparticle diffusion and Boyd's film diffusion models were applied to investigate the CO diffusion mechanism, the intraparticle diffusion model could well distinguish the rate-limiting step during CO adsorption process. This solid amine adsorbent could be regenerated with nitrogen stream at 75°C, and it kept stable CO adsorption capacity after eight adsorption-desorption cycles. All these features indicated that this porous polymer based adsorbent has a high potential for CO capture and separation from flue gas.