钙基CO_2吸收剂循环反应特性的试验与模拟

Experimental Research and Modeling of Multiple Carbonation/Calcination Cycle of Ca-based CO_2 Sorbents

合成了3种不同质量配比的钙基CO2吸收剂CaO/Ca12Al14O33,并对CaO/Ca12Al14O33、石灰石、白云石的循环煅烧/碳酸化特性进行试验研究,以考察吸收剂的转化率随循环反应次数的变化规律。试验结果表明,3种吸收剂反应活性均随循环反应次数的增加而降低;在850℃煅烧温度下,CaO/Ca12Al14O33(75%/25%)吸收剂在第10次循环后其循环转化率保持在51.7%左右;在900℃煅烧温度下,吸收剂活性下降较快,CaO/Ca12Al14O33的反应活性高于石灰石和白云石,且当CaO和Ca12Al14O33的质量比为75%/25%时最优。建立了吸收剂的循环转化率模型以及循环碳酸化过程动力学模型,为反应器的设计提供理论依据。

A Ca-based CO2 sorbent, CaO/Ca12Al14O33, with three different weight ratios was synthesized. The cyclic reaction characteristic of CaO/Ca12Al14O33, limestone and dolomite with CO2 were investigated by using TGA. Experimental results indicate that the cyclic conversions of the three absorbents decrease with an increase in cyclic reaction numbers and the cyclic conversion of CaO/Ca12Al14O33 （75%/25%） retains 51.7% after 10th cycle at 850 ~C calcination temperature. The conversion of the sorbents decreases more evidently at more rigorous calcination condition with 900℃. The capability of CaO/Ca12Al14O33 is better than that of dolomite and limestone and CaO/Ca12Al14O33 achieves the best performance with an optimal mass ratio of 75%/25%. The kinetic models of cyclic conversion and carbonation for the sorbents were developed to offer basic theory for reactor design.