CaO/FA吸收剂高温吸收CO2及穿透特性

利用完全煅烧后的CaO和粉煤灰（Fly Ash）为材料制备了CaO/FA吸收剂。在350~650℃温度范围内对其碳酸化反应特性进行了研究。考察了不同质量比的CaO/FA吸收剂吸收CO2的性能。利用XRD、N2吸附等表征手段对吸收剂反应前后产物进行了表征。结果表明：通过水合反应过程，吸收剂比表面积增大，孔径在5~40nm范围内属于中孔，有利于减小CO2向颗粒内部的扩散阻力。CaO/FA吸收剂CO2吸收量随温度的升高而增加。当CaO与粉煤灰的质量比为3:1时制备的吸收剂具有最好的CO2吸收能力，在650℃时其最大CO2吸收量达到了227.13mg/g。通过多次循环试验后，吸附剂仍保持较高的CO2吸收量与稳定吸收性能。失活模型可以很好地预测CaO/FA吸收剂吸收CO2的过程，并得到了理想的吸收速率常数和失活速率常数。

High-temperature absorption of CO2 and breakthrough characteristics of CaO/FA sorbents

The CaO/FA sorbents were prepared by calcination and hydration reaction using calcium hydroxide and fly ash from Coal-fired power plant waste.The CO2 absorption capacity of CaO/FA sorbents in a fix-bed reactor in temperature range of 350—650℃,and effect of mass ratio of CaO and fly ash on it was investigated.The morphological properties of those sorbents before and after absorbing CO2 were characterized by using XRD,SEM and N2 adsorption-desorption.And a deactivation model was used to fit breakthrough data obtained.The results indicated that,the sorbents have high BET surface area and large pore volume after hydration reaction,CO2 absorption capacity of CaO/FA sorbents increases with rise of reaction temperature,and have the minimum value at 350℃ for all of CaO/FA sorbents.Its increase become not so obvious when the reaction temperature is in the range of 450—650℃.It was also found that CaO/FA sorbents show a maximum CO2 absorption capacity 227.13 mg·g-1 at 650℃ if the mass ratio of CaO and fly ash was 3∶1.After 9 use cycles the CaO/FA sorbents still have high and stable absorption capacity.In addition,CO2 breakthrough curves of CaO/FA sorbents can well be fitted with a deactivation model,and the absorption and deactivation rate constants were obtained.