典型煤种高温热解/气化下As/Cd/Pb/Zn的迁移转化规律

Trace Elements Migration Transformation Rule of As/Cd/Pb/Zn During Typical Coal Pyrolysis and Gasification Under High Temperature

在管式炉上对锡盟褐煤、西武匠烟煤和南陈铺无烟煤等典型煤种热解气化过程中痕量元素As/Cd/Pb/Zn的迁移转化规律开展研究.3种煤在气化过程中,随着温度的升高,其痕量元素的释放率有不同程度（10%~36%）的提高.相对于热解,Cd倾向于在低温下释放,CO_2气化气氛明显促进了Cd在高温区的释放;Pb在800~1,200,℃下释放强烈,与热解情况一致;而Zn和As与温度呈线性关系,对温度敏感性不大.研究表明,As和Cd的释放率随着煤化程度的提高而下降,下降幅度最大可分别达到15%,和30%,;而Pb和Zn则与煤化程度没有明确的关系.相对N_2热解,CO_2气化气氛对4种痕量元素的释放均有不同程度的促进作用,且对南陈铺无烟煤痕量元素释放的促进作用大于锡盟褐煤和西武匠烟煤.

Three kinds of coal, Ximeng lignite, Xiwujiang bituminous coal and Nanchenpu anthracite, were used to study the trace elements migration transformation rule of As/Cd/Pb/Zn in the process of coal pyrolysis and gasifica- tion. It was found that the trace elements release rate was improved by 10%--36% with the increase of temperature during coal gasification. Cd tends to be released under low temperature, and CO2 gasification atmosphere signifi- cantly promotes the release of Cd under high temperature. Pb is released significantly at 800 ℃-1 200 ℃. Zn and As are released linearly with the rising temperature, showing little sensitivity to temperature. The results also show that the release rates of As and Pb decrease with the increase of coal rank, and the maximum decrease reaches 15% and 30%, respectively, while the release rates of Pb and Zn have little to do with coal rank. CO2 gasification at- mosphere promotes the trace elements release rate to different degrees, and the promotion of trace elements release rate on Nanchenpu anthracite is greater than that on Ximeng lignite and Xiwujiang bituminous coal.