中温下热解对半焦燃烧反应性的影响

The Impact of Medium-level Temperature Pyrolysis on Semicoke Combustion Reactivity

用热天平(TGA)和粉末X射线衍射方法(XRD)分别测量了两种低变质程度烟煤和一种无烟煤的半焦在400～1 400 ℃热解过程中燃烧反应性及其结构的变化,探讨了低变质煤的反应性变化的原因.研究发现,半焦反应性下降主要与热解过程中半焦晶格化与矿物质催化作用的逐渐消失有关,温度低于900 ℃,原煤脱去大部分挥发份形成的半焦进一步热解时,晶格化现象不很显著,但反应性明显下降,反应性的降低主要与煤中矿物质在热解过程中的失活有关.

By employing the method of thermogravimetric analysis and powder X-ray diffraction measured respectively were the combustion reactivity and structural changes of the semicoke of two low-rank bituminous coals and one type of anthracite during the process of pyrolysis at 400～1400 ℃.The cause of the variation in reactivity of the low-rank coals was also discussed.A study has revealed that the lowering of semicoke reactivity is mainly due to the semicoke crystal-lattice growth and the gradual disappearance of catalytic action of minerals during the pyrolysis process.At a temperature lower than 900 ℃ during the further pyrolysis of the semicoke formed by raw coal being deprived of a majority of volatile matter the crystal-lattice growth phenomenon is not very significant.However,there emerged a marked reduction of reactivity,which is mainly related to the loss of activity of minerals in coal during the pyrolysis process.