CaCl2添加对热解煤中汞析出规律影响的实验研究

在程序升温热解反应装置上，研究了低氯煤中添加不同氯含量（质量分数0.1%、0.3%、0.5%）的CaCl₂对煤热解过程中汞析出规律的影响。实验结果表明，温度是影响汞析出的关键因素；随着氯添加量的增加，Hg²⁺析出比例呈上升趋势，且汞的最佳析出温度降低，汞的释放率也有所降低；随着热解气氛中O₂比例的增加，Hg²⁺比例也略有增加；较高的升温速率能加快汞的释放，也能提高Hg²⁺的比例。低氯煤中添加氯化钙能够强化单质汞的氧化。

Experimental study on mercury release behavior during coal pyrolysis with calcium chloride addition

Mercury release and speciation behavior during coal pyrolysis with the addition of calcium chloride in different chlorine contents of 0.1%,0.3% and 0.5% in mass was studied in a temperature-programmed tube furnace. The concentration of gaseous mercury was monitored online with an online mercury analyzer. The results show that the temperature is a key factor for the mercury releasing during coal pyrolysis. With the rising of calcium chloride addition in coal, the percentage of Hg²⁺ increases, while the temperature of maximum mercury releasing and the release of total mercury decrease. The percentage of Hg²⁺ also increases to some degrees with the increase of O₂ percentage raised. Higher heating rate can promote the mercury release in coal and enhance the proportion of Hg²⁺ in flue gas. The study indicates that the calcium chloride addition into the low-chlorine coal can enhance the oxidation of Hg⁰.