真空条件下高分辩质谱对不同煤质热解释放CO_2分析

煤的热解机理和热解物质的形成与释放特征是煤田火灾研究领域的重要基础问题.本文以淮北不同煤种(烟煤,无烟煤,天然焦)为研究对象,在高真空条件下对样品进行热解,利用分子泵即时将热解气体产物抽入高分辨质谱检测器,在线分析热解过程中CO2的释放规律.研究结果表明:天然焦热解过程中产生的CO2,主要是样品和体系中残留以及吸附在煤微孔隙中O2分子反应生成;烟煤和无烟煤热解产生的CO2,主要是其内部含氧官能团在受热过程中分解形成,为不同煤种自燃发火防治提供资料.

Release of Carbon-dioxide during Pyrolysis of Different Rank Coal Samples with High-precision Mass-spectrum under Vacuum Condition

The different rank coals including anthracite, bituminite and cokenite were collected from the Huaibei coalfield and pyrolysis experiments were carried out under Vacuum Condition. The gases including carbon-dioxide released were determined by High Resolution Mass Spectrometer. The characteristics of carbon-dioxide were analyzed, and the results showed that the carbon-dioxide from nature-coke was due to the reaction between oxygen absorbed in micropore of nature-coke and carbon from system, while the carbon-dioxide from anthracite and bituminite was mainly due to the decomposition of oxygen-bearing functional groups during coal pyrolysis.