Abstract The combustion behaviors of chars derived from coal pyrolysis under a CO-containing atmosphere were analyzed by thermogravimetry, and the structural changes of char samples prepared under different pyrolysis conditions (temperature and atmosphere) were characterized by scanning electron microscopy, X-ray diffraction, and CO2 adsorption methods. The apparent activation energies (Ea) of char-N2 and char−CO under non-isothermal combustion conditions were obtained by the Flynn–Wall–Ozawa method. Char-N2 exhibited higher combustion reactivity than char−CO, a more developed micropore structure, a more ordered carbon microcrystalline structure, and a higher Ea at the same pyrolysis temperature. In a CO-containing pyrolysis atmosphere, the carbon particles precipitated by the disproportionation reaction blocked the pores (inhibiting the escape of volatiles), reduced the number of active char sites, and increased the order of the carbon structure. The volatile content significantly influenced the Ea only during the initial conversion rate of char combustion. Based on the high reactivity of the disordered carbon structure, chemical reaction is the likely limiting factor of char-N2 combustion, whereas diffusion should mainly limit char−CO combustion.

中文翻译：

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含 CO 气氛下煤热解焦炭的燃烧行为

摘要 采用热重法分析了煤在含 CO 气氛下热解得到的焦炭的燃烧行为，并通过扫描电镜、X 射线衍射、X 射线衍射等表征了不同热解条件（温度和气氛）下制备的炭样品的结构变化。和 CO2 吸附法。非等温燃烧条件下炭-N2 和炭-CO 的表观活化能（Ea）通过Flynn-Wall-Ozawa 方法获得。在相同的热解温度下，Char-N2 表现出比 char-CO 更高的燃烧反应性、更发达的微孔结构、更有序的碳微晶结构和更高的 Ea。在含 CO 的热解气氛中，歧化反应析出的碳颗粒堵塞了孔隙（抑制了挥发物的逸出），减少了活性炭点的数量，增加了碳结构的有序性。挥发物含量仅在炭燃烧的初始转化率期间显着影响 Ea。基于无序碳结构的高反应性，化学反应可能是 char-N2 燃烧的限制因素，而扩散应主要限制 char-CO 燃烧。