含铁煤热解过程中HCN形成的主要影响因素

煤中矿物质和外加含铁化合物对氮氧化物主要前驱体之一HCN在热解过程中的释放具有重要的作用。使用固定床反应器进行了程序升温过程中Ar气氛下的神东、平朔和常村原煤以及相应的脱灰煤、浸渍法加铁煤和沉淀法加铁煤的热解实验，重点研究了HCN释放的影响因素。实验结果表明，煤中的矿物质和外加铁对HCN释放的作用较大程度上取决于煤的变质程度，变质程度越低的煤影响越明显；矿物质和含铁化合物的作用主要出现在升温时挥发分释放的过程，并且因添加方式不同以及煤种不同而对HCN的形成与释放具有不同的作用规律；沉淀法添加的铁在变质程度较低的煤中分散效果较好，对HCN生成量的减少作用明显。同时热解反应温度、煤样粒度和恒温阶段停留时间的长短对HCN释放也有影响。

Key factors influencing the release and formation of HCN during iron-containing coal pyrolysis

Minerals inherently presented in coal and iron containing compounds externally added have an important influence on the formation and release of HCN—one of the NOx precursors during coal pyrolysis. The experiments on the pyrolysis of raw coal and demineralized coal with different carbon contents and iron containing compounds were carried out in a fixed bed quartz reactor with the temperature programmed. The influencing factors of HCN formation and release during coal pyrolysis were examined. The results show that the effect of iron containing compounds in coal on HCN release depends on the coal types. And the iron added to coal by impregnation and precipitation method can significantly reduce the formation of HCN for lower coalification coals . Additionally, the effects of particle size and reaction time on HCN formation during pyrolysis of coal with iron were also studied.