MgO对喷吹煤粉热解率的影响

Effect of MgO on pyrolysis rate of pulverized injection coal

利用电弧等离子体高温热解装置模拟高炉喷吹煤粉高温热解试验,对其热解后的固相残留物采用XRD和红外光谱方法进行检测分析,考察了在混合煤粉中添加助燃催化剂MgO对煤粉的热解率的影响和及其助燃机理。通过分析试验结果得出:在混合煤中添加MgO有助于提升煤粉的热分解能力,当MgO的质量分数在8.01%时煤粉热解率达到了62.17%,与原煤分解率47.51%相比增加了近15%,对混合煤粉的热分解具有比较明显的催化作用;同时MgO的加入使煤粉残留物芳香片层的堆垛高度和芳香碳环的缩合程度均有所提高;MgO能够促进煤粉发生脱碳裂解反应使芳香烃网络分子断裂,生成小分子含氧基团从而促进分解和燃烧。

The high-temperature pyrolysis of pulverized coal injection in blast furnace was simulated by arc plasma pyrolysis equipment.The pyrolysis solid-phase residue was analyzed by XRD and IR.The effect of MgO on coal pyrolysis rate and its combustion mechanism were investigated.The results show that the addition of MgO in the mixed coal can improve the thermal decomposition of coal.When the addition of MgO content is 8.01 mass%,the pyrolysis rate of pulverized coal reaches 62.17% which increases by nearly 15%compared with the raw coal pyrolysis rate of 47.51%.So the addition of MgO has obvious catalytic effect on the thermal decomposition of mixed pulverized coal.With the addition of MgO,the stacking height of aroma flakes and the condensation degree of aromatic carbocycles are improved.MgO can promote the decarburization reaction of pulverized coal to break the network of aromatic hydrocarbons,resulting in small molecular oxygen-containing groups to promote decomposition and combustion.