钙基吸收剂循环锻烧/碳酸化反应过程特性研究

在常压煅烧/碳酸化反应器系统上，研究随着循环反应次数N的变化操作条件对钙基吸收剂循环煅烧/碳酸化反应（CCR）吸收CO2过程中碳酸化转化率XN的影响规律，操作条件包括碳酸化温度TCAR、煅烧温度TCAL、颗粒粒径d等。给出了综合碳酸化转化率YN的定义，并用YN比较不同钙基吸收剂吸收CO2能力的大小。结果表明：TCAR为700℃时石灰石的XN最高，白云石则在650℃时XN最高，在650～700℃时白云石的XN远高于石灰石，但它们的YN相差不大；当TCAL超过1050℃时石灰石的XN急剧衰减，而白云石的XN则衰减程度不大，在高温煅烧时白云石的YN比石灰石更高；随粒径的增大，石灰石的XN逐渐减小，而白云石则存在最佳的粒径分布使XN最大，粒径的变化对石灰石的XN影响更大。随循环CCR反应次数的增加，石灰石煅烧产物的微观结构变化较大，而白云石则变化较小。

Carbonation Characteristics in Calcium-sorbents Cyclic Calcination/Carbonation Reaction Process

In the Ca-based sorbents cyclic calcination/ carbonation reaction (CCR) process for CO2-absorbing, the effect of operating parameters including carbonation temperature (TCAR), calcination temperature (TCAL) and particle size (d) on carbonation conversion XN was experimentally investigated with a increasing number of cycles in an atmospheric CCR system. And the general carbonation conversion YN was proposed in order to compare CO2-absorbing capacity of the different Ca-based sorbents. The experimental results show that when TCAR is about 700 ℃ XN for limestone is maximum, and the optimum TCAR for dolomite is about 650℃. Although XN for limestone is much higher than dolomite, the difference of their YN is little when TCAR is in 650~700 ℃. And if TCAL is beyond 1050 ℃ XN for limestone decays sharply, but it is negligible to dolomite. XN for dolomite is far higher than limestone in the high TCAL. XN for limestone decreases with the particle size increasing, and there is an optimum particle size range with particle size increasing which XN for dolomite reaches maximum in. The particle size plays a more important role in limestone carbonation process than dolomite. The microstructure of calcines derived from limestone changes a lot with number of cycles, but the change is not so obvious for dolomite.