Fourier transform infrared spectroscopy(FTIR)and Carbon-13 nuclear magnetic resonance(^(13)C NMR)techniques were applied to establish the molecular models of anthracite combusted at 490℃ and 690℃(490-C and 690-C).Th...Fourier transform infrared spectroscopy(FTIR)and Carbon-13 nuclear magnetic resonance(^(13)C NMR)techniques were applied to establish the molecular models of anthracite combusted at 490℃ and 690℃(490-C and 690-C).The evolution laws of functional groups were investigated based on the constructed models and quantitative changes calculated by FTIR results.The content of aromatic groups kept decreasing before 500℃;-CH_(3)/-CH_(2)-showed a rising trend during combustion;and the content of oxygen functional groups kept declining before 400℃.The chemical formulas of 490-C and 690-C were C_(217)H_(106)O_(12)N_(2)S_(2) and C_(201)H_(59)O_(8)N_(3)S_(2),respectively.690-C model was more compact than that of original anthracite and 490-C due to the spilt of carbon skeleton and the shedding of aliphatic chains during combustion.Total sulfur content in anthracite showed a sudden rise at 690℃ which could be attributed to the generation of organic thiophene;one more pyrrole in 690-C model resulted from the conversion of pyridine at such high temperature.展开更多
基金supported by Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering(Grant No.2019-KF-13)。
文摘Fourier transform infrared spectroscopy(FTIR)and Carbon-13 nuclear magnetic resonance(^(13)C NMR)techniques were applied to establish the molecular models of anthracite combusted at 490℃ and 690℃(490-C and 690-C).The evolution laws of functional groups were investigated based on the constructed models and quantitative changes calculated by FTIR results.The content of aromatic groups kept decreasing before 500℃;-CH_(3)/-CH_(2)-showed a rising trend during combustion;and the content of oxygen functional groups kept declining before 400℃.The chemical formulas of 490-C and 690-C were C_(217)H_(106)O_(12)N_(2)S_(2) and C_(201)H_(59)O_(8)N_(3)S_(2),respectively.690-C model was more compact than that of original anthracite and 490-C due to the spilt of carbon skeleton and the shedding of aliphatic chains during combustion.Total sulfur content in anthracite showed a sudden rise at 690℃ which could be attributed to the generation of organic thiophene;one more pyrrole in 690-C model resulted from the conversion of pyridine at such high temperature.
