低阶煤中含氧官能团干燥前后的演变规律
Transition of the oxygen-containing functional groups of low rank coal during drying process
-
摘要: 采用傅里叶红外光谱法对经不同干燥过程前后低阶煤中官能团进行研究,基于拟合处理方法分析了煤中主要官能团在干燥过程中的变化规律。结果表明,在低温干燥和高温干燥过程中,随干燥温度的增加,低阶煤中主要官能团均呈现先减少后增加的趋势。当低温干燥温度超过190℃,高温干燥温度超过600℃时,煤中主要官能团增多,表明该煤被严重氧化。在模拟烟气干燥过程中,亚甲基是低阶煤脂肪烃结构中最易被氧化的部分,烟气中含氧量越高,煤受氧气氧化作用越强。在高温600℃模拟烟气干燥过程中,干燥介质中的氧气主要氧化煤分子结构中的芳香烃,干燥后低阶煤的自燃倾向性最弱,不易发生复吸现象。Abstract: The variations in the main functional groups of two different low rank coals during drying process were in- vestigated using Fourier-transform infrared spectrometer based on the curve-infrared analysis. The results show that the main functional groups of the coals decrease first and then increase with the increase of temperature during the low and high temperature drying process. When above 190 ℃ in the low temperature drying process and above 600 ℃ in the high temperature drying process,the main functional groups of the coals are seriously oxidized. Methylene contained in the aliphatic hydrocarbon structures of the low rank coal is very apt to be oxidized during the drying process. The high- er the oxygen content in drying agent,the more highly oxidized the coal during the simulated flue gas drying process. The low rank coal dried under 600 ℃ has the weakness of spontaneous combustion tendency and re-absorption feature during the high temperature flue gas drying process. Meanwhile,the aromatic hydrocarbon of the coal molecular struc- tures can be oxidized by the oxygen of drying agent.
下载: