A kinetic study of gaseous potassium capture by coal minerals in a high temperature fixed-bed reactor
A kinetic study of gaseous potassium capture by coal minerals in a high temperature fixed-bed reactor
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DOI：
10.1016/j.fuel.2008.05.003
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发表时间：
2008-11
期刊：
影响因子：
7.4
通讯作者：
Yuanjing Zheng;P. Jensen;A. Jensen
中科院分区：
文献类型：
--
作者：
Yuanjing Zheng;P. Jensen;A. Jensen
在实验室规模的高温固定床反应器中，采用单颗粒吸附剂，研究了气态氯化钾与煤矿物的反应。所用的煤炭矿物包括高岭土、莫来石、二氧化硅、氧化铝、烟煤灰和褐煤灰，这些矿物形成了长圆柱状的球团。高岭土和烟煤灰分中都含有大量的硅和铝，表现出良好的钾捕集特性。实验结果表明，高岭土对钾的捕获量与气体含氧量无关。当温度高于450°C时，高岭土释放出水并形成偏高岭土。在900-1300℃范围内，偏高岭土颗粒所吸收的钾量随着反应温度的升高而减少，直到1500℃时，随着反应温度的升高而增加。在低于1300℃时，预制的莫来石与KCl2不发生反应，但在1300-1500℃温度范围内，莫来石的增重仅略小于高岭土。
The reactions between gaseous potassium chloride and coal minerals were investigated in a lab-scale high temperature fixed-bed reactor using single sorbent pellets. The applied coal minerals included kaolin, mullite, silica, alumina, bituminous coal ash, and lignite coal ash that were formed into long cylindrical pellets. Kaolin and bituminous coal ash that both have significant amounts of Si and Al show superior potassium capture characteristics. Experimental results show that capture of potassium by kaolin is independent of the gas oxygen content. Kaolin releases water and forms metakaolin when heated at temperatures above 450°C. The amounts of potassium captured by metakaolin pellet decreases with increasing reaction temperature in the range of 900–1300°C and increases again with further increasing the temperature up to 1500°C. There is no reaction of pre-made mullite with KCl at temperatures below 1300°C. However, the weight gain by mullite is only slightly smaller than that by kaolin in the temperature range of 1300–1500°C. A simple model was developed for the gas–solid reaction between potassium vapor and metakaolin pellet at 900°C.