Preparation and kinetic study of organic amine-loaded ion-exchange resin as CO_2 adsorbents

摘要

Organic amine adsorbents prepared by template method using ion exchange resin (D001) as support and polyethyleneimine (PEI) as a modifier, and the preparation process was optimized by orthogonal experiment plan. The results showed that adsorbents prepared under conditions (the copper ion concentration was 0.2 mol/L, the ultrasonic time was 3 hr, and the PEI loadings were 30%) had an excellent CO_2 adsorption properties. The effects of temperature and gas influent velocity on CO_2 adsorption properties were investigated in a fixed bed reactor. When PEI loadings were 30%, the adsorption temperature was 65°C and the gas influent velocity was 40 ml/min, organic amine adsorbents performed a better PEI dispersion, stability, and CO_2 adsorption capacity. Maximum CO_2 adsorption capacity was 4.00 mmol/g. Besides, the CO_2 adsorption capacity decreased by only 10% after 10 cycles of adsorption-desorption tests, attribute to a small amount of PEI was volatilize during the regeneration process. The external diffusion was eliminated by increasing the gas influent velocity, and the adsorption data were well fitted the Weber-Morris particle diffusion model, indicating that CO_2 adsorption was controlled by internal diffusion.