Abstract:

According to gasification behavior of coal chair in high temperature flue gas, high temperature reaction characteristics of coal char in high temperature flue gas, using FactSage 6.1 was calculated and gasification behavior was analyzed using thermogravimetric analyzer. Dynamic precipitation characteristics of gas products under different temperatures, gas ratios and particle sizes were further studied by conducting the settling furnace experiments. At the same time the evaluation indexes, including α, β and LHV values were calculated as well. The results showed that with the increase of temperature, the contents of gas products H₂ and CO increase, the values of β, α and LHVincrease, and the contents of CH₄ and CO₂ decrease. At a constant temperature of 1200℃, the values of β and α increased from 10.80% and 5.21% at a CO₂/CO ratio of 10∶70 to 24.71% and 41.06% at a CO₂/CO ratio of 50∶30, respectively. Moreover, with the increase of CO₂/CO ratio, the inhibition of the coal char gasification reaction was weakened by high temperature flue gas. By comparing the effects of reaction temperature and particle size of coal char on gasification, it can be concluded that the effect of reaction temperature on gasification reaction in coal char is much larger than the size of coal char. The feasibility of preparing high-quality flammable gas by spraying coke into high temperature flue gas was verified by experiments.

Key words: coal char, high temperature flue gas, gas product, settling furnace

摘要：

针对高温烟气中煤焦的气化行为，本文采用FactSage 6.1计算了煤焦在高温烟气下的高温反应特性，并利用热重分析仪分析了煤焦气化行为。通过沉降炉实验进一步研究了不同温度、气体配比、粒径条件下气体产物的动态析出特性，同时计算了评价指标α、β、LHV值。结果表明：随着温度的升高，气体产物H₂和CO的含量增加，β、α、LHV值增大，CH₄和CO₂的含量下降。在温度为1200℃时，β、α值分别由CO₂/CO比为10∶70时的10.80%、5.21%增加到CO₂/CO比为50∶30时的24.71%、41.06%。同时，随着CO₂/CO比值的增大，高温烟气对煤焦气化反应抑制减弱。通过对比反应温度和粒径对煤焦气化反应的影响，得出反应温度远大于粒径对煤焦气化反应的影响。通过实验验证了向高温烟气中喷吹煤焦制备高品质可燃气体方法的可行性。

关键词: 煤焦, 高温烟气, 气体产物, 沉降炉