摘要
以先锋褐煤(XF)为原料,在高压反应釜中考察了水热处理过程中褐煤的结构变化,通过13C固体核磁共振(NM R)和傅里叶变换红外光谱进行了分析表征。结果表明,在低于240℃的水热处理条件下,煤有机分子结构中的弱化学键有一定断裂,含氧官能团逐步减少;水中氢以离子形态迁移至褐煤中,处理后褐煤结构中甲基比例先增加后减少,次甲基比例由原煤的4.80%增加至XF-240的13.16%;释放的气体中主要是CO_2,烃类气体组分随处理温度的升高略有增加。当水热处理温度高于240℃时,褐煤中部分共价键开始断裂,释放的烃类气体(C1-4)由240℃时的2.13%增加至300℃时的8.59%,脂肪碳比例由XF-240的44.83%降低至XF-300的39.49%,与氧连接的碳比例由XF-240的12.57%降低至XF-300的1.49%。水热处理对褐煤的脱氧提质效果显著,300℃时氧含量降低约30%,芳香碳比例增加至60.50%,比原煤提高19%。
Xianfeng lignite（ XF） was used as rawmaterial to investigate its structural evolution during hydrothermal treatment in a 500 m L autoclave. The structure was characterized by solid state 13C nuclear magnetic resonance（ NMR） and Fourier transform infrared spectroscopy（ FT-IR）. The results showthat the carbon contents increase and oxygen contents decrease after hydrotnermal treatment. The weak bonds in lignite are broken and the oxygen functional groups decrease gradually during hydrothermal treatment below240 ℃.Hydrogen is donated from water to lignite through ionic pathway and transferred into lignite. The methyl carbon increases at 200 ℃ and then decreases. The methenyl carbon increases from 4. 80% in XF to 13. 16% in XF-240. The released gas is mainly CO2 during hydrothermal treatment. The hydrocarbon composition in released gas increases with the treated temperature. The covalent bonds are broken above 240 ℃. The hydrocarbon composition in released gas increases from 2. 13% at 240 ℃ to 8. 59% at 300 ℃. The aliphatic carbon in lignite deceases from 44. 83% in XF-240 to 39. 49% in XF-300. The oxygen-linked carbon in lignite decreases from 12. 57% in XF-240 to 1. 49% in XF-300. Hydrothermal treatment plays a role in deoxygenation and upgrading of rawlignite. The oxygen contents decrease by about 30% and the aromatic carbon increases to 60.50% at 300 ℃.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2016年第2期129-137,共9页
Journal of Fuel Chemistry and Technology
基金
国家重点基础研究发展规划(973计划
2011CB201304)项目资助~~
