Abstract In order to study the high-temperature pyrolysis behavior of bituminous coal in the drop tube furnace (DTF) and better utilization of the obtained char, a typical Shenhua bituminous coal (SH) was pyrolyzed in a DTF at the temperatures of 1000–1300 °C (100 °C increments). The obtained char was then characterized using BET and FTIR methods, while its combustion, gasification and pollutant emission characteristics were explored by a thermogravimetric analyzer and online flue gas analyzer. Results show that higher pyrolysis temperature leads to more CO and less CH4 for the increased free radical rearrangement by high heating rate and carbon reduction reactions at high temperatures. Pyrolysis generally decomposes the functional groups, increases the volume of char pores, and upgrades the rank of coal. The combustion activation energy increases from 22.99 kJ/mol to 27.42 kJ/mol and the gasification is hindered with the higher pyrolysis temperature. It is notable that the NOx and SO2 emissions of the obtained char combustion are both below 30 mg/s-MJ. High-temperature pyrolysis can enhance the evolution of NH3 and HCN as volatiles, thus decreasing the NOx formation in further char combustion stages while partly decomposing the organic and inorganic sulfur compounds to impact the SO2 emission.

中文翻译：

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烟煤在下降管式炉中的高温热解行为和所得焦炭的进一步表征

摘要 为了研究烟煤在下降管式炉（DTF）中的高温热解行为和得到的焦炭的更好利用，将典型的神华烟煤（SH）在 DTF 中在 1000-1300 的温度下进行热解。 °C（100 °C 增量）。然后使用 BET 和 FTIR 方法对获得的炭进行表征，同时通过热重分析仪和在线烟气分析仪探索其燃烧、气化和污染物排放特性。结果表明，较高的热解温度会导致更多的 CO 和更少的 CH4，因为高温下的高加热速率和碳还原反应会增加自由基重排。热解通常会分解官能团，增加炭孔体积，并提升煤的等级。燃烧活化能从 22.99 kJ/mol 增加到 27.42 kJ/mol，热解温度升高阻碍了气化。值得注意的是，所得炭燃烧的 NOx 和 SO2 排放均低于 30 mg/s-MJ。高温热解可以促进 NH3 和 HCN 作为挥发物的释放，从而减少进一步炭燃烧阶段的 NOx 形成，同时部分分解有机和无机硫化合物以影响 SO2 排放。