Abstract: The CaO/FA sorbents sorbents were prepared by calcination reaction and hydration reaction using calcium hydroxide and fly ash from Coal-fired power plant waste. The CO2 adsorption capacity of CaO/FA sorbents was investigated in a fix-bed reactor within the temperature range of 350~650℃. The effect of different mass ratio of CaO and fly ash were investigated. The morphological properties of those sorbents before and after the carbonation reaction were characterized by using XRD, SEM and N2 adsorption-desorption. And the deactivation model was used to analysis the experimental breakthrough data. The results indicated that, the sorbents have high BET surface area and large pore volume after hydration reaction, with the rise of carbonation reaction temperature, the CO2 adsorption capacities of CaO/FA sorbents also on the increased. All of CaO/FA sorbents have the minimum of CO2 adsorption capacity when the carbonation temperature at 350℃. When the reaction temperature is within the range of 450~650℃, the CO2 adsorption capacity of those sorbents increased but not obviously. It was found that, CaO/FA sorbents showed a higher CO2 adsorption capacity when the mass ratio of CaO and fly ash was 3:1 and the reaction temperature reach to 650℃, the maximum CO2 adsorption amount reached 227.13mg/g. The CaO/FA sorbents have high and stable adsorption capacity after 9 cycles. In addition, the CO2 breakthrough curves of CaO/FA sorbents are well predicted with the deactivation model, and obtained good adsorption and deactivation rate constants.

Key words: carbonation reaction, fix-bed reactor, deactivated model, CO2 capture