钙、钠添加剂对平朔煤热解特性的影响

Effect of calcium and sodium additives on the pyrolysis characteristics of Pingshuo demineralized coal

采用盐酸、氢氟酸分步酸洗脱除平朔原煤中灰分,再用浸渍法向脱灰煤中添加Ca(Ac)_2和NaAc,制得实验样品。利用固定床反应器对实验样品进行热解实验,气相色谱在线检测气相产物,热天平分析热解过程热量的变化。结果表明:添加钙盐和钠盐对煤热解过程中形成的H_2、CH_4、CO等可燃产物起始温度、最大温度和累积产率均有不同程度的影响,热解气体的组成分布也随添加物的存在而不同。负载钙盐和钠盐均使热值最高的H_2累积释放量增加了10%以上。DTA分析显示,添加剂及负载量的不同对煤热解过程中的热量变化具有不同的影响,其热效应的变化与热解气体的释放有着密切的关联。

The minerals in Pingshuo raw coal were removed by hydrochloric and hydrofluoric acid washing method. Coals loaded calcium and sodium were obtained by impregnating the demineralized coal in the Ca （Ac）2 or NaAc solution. The pyrolysis experiments of coal samples were carried out in a fixed - bed reactor. The gaseous products form coal pyrolysis were analyzed by gas chromatography. The heat changes during pyrolysis was measured by ther- mal analytical balance. The experimental results show that calcium and sodium in coal sample decrease the initial temperature and increase the total gaseous products yield during changed and the H2 accumulated yield in pyrolysis gas of coals pyrolysis. The gas component from coal pyrolysis is loaded calcium and sodium are 10% more than that from demineralized coal. DTA analysis show that the types and amounts of additive loaded are the main factors influencing thermal effects during coal pyrolysis, the changes of the thermal effect and the release of pyrolysis gases are closely related.