FTIR study of structural characteristics of different chemical components from Yimin Lignite

Structural characteristics of different chemical components of Yimin lignite were analyzed by using Fourier transform infrared spectroscopy (FTIR),the curve-fitting analysis was employed to characterize the infrared spectrum different chemical components of Yimin lignite by using origin 7. 5 software,and the FTIR structure parameters were also calculated. The results were obtained as following:for the demineralized coal,comparing with the raw coal,the car- boxyl vibration peak became sharp,two adjacent hydrogen increased and four adjacent hydrogen decreased,aliphatic CH2 vibration decreased and aliphatic CH3 vibration increased,FTIR structural parameters I1 ,I2 and A all increased, which demonstrated its good hydrocarbon generation capacity;for humic acid and asphaltene,they have more carboxyl- ic acid and OH-π hydrogen bond,more two adjacent hydrogen and five adjacent hydrogen,more aliphatic CH vibra- tion and less CH2 vibration,the humic acid has the most aliphatic hydrogen,indicating that the aliphatic hydrocarbons in humic acid and asphaltene is short and high branched;for the residue,it has more aromatic C C vibration,and the aliphatic chain is long and less branched.