Construction Of Molecular Model And Research On The Distribution Of The Organic Sulfur In Xinyu Coking Coal

Xinyu coking coal was separated to four group components, i.e.heavy component, loose medium component, and dense medium component, to study the distribution of the organic sulfur and construction of molecular model. We performed sequential thermal dissolution extraction of group components and get the residues by extracting the soluble small molecule. The extracts were tested via GC/MS and analysis of the distribution and dissolution regularities of small soluble molecules and the thermally dissolution residues were analyzed via FT-IR, XPS, and 13 C NMR to get the feature information of residues framework structure. Using Gaussian 09 W software to simulate the optimization structure and calculated the IR spectra of the framework structure model. The results indicated that:3 sulfur-containing compounds were detected in thermal dissolution extracts from HC, LMC, and DMC. They are naphthalene [2,3-d] thiophene, 3-methyl dibenzothiophene, and 4, 9-two methyl naphthalene and [2,3-b] thiophene. Thiophenic sulfur is the main form of organic sulfur, their contents are 81.68%, 85.72%, and 83.80%, followed by sulfoxide sulfur and mercaptan/thioether.Carbon atoms of thermal dissolution residues framework structure are mainly for C=C and C-H forms, and their contents（amount of substance fraction, the same below） are 89.51%, 87.89%, and 90.02%, followed by C-O. Oxygen atoms existed as the form of hydroxyl and ether oxygen bond, their contents are 66.52%, 63.74%, and 76.51%; secondly for COO- and C=O. Pyrrole-type nitrogen is the main form of nitrogen atorm in each group component, their contents are 52.99%, 60.23%, and 57.46%, then pyridine-type nitrogen.The aromaticity of thermal dissolution residues framework structure are 0.699, 0.712, and 0.708, aliphatic carbon content are 24.3%, 25.8%, and 25.8%, aliphatic hydrogen and aromatic hydrogen ratio are 1.89, 1.75, and 1.27, and the XBP are 0.24, 0.22, and 0.22. Aromatic unit mainly for 2-3 ring condensed polycyclic aromatic and the subsidiary role of four-ring, The structural formulas of group components framework structure model are C₂₈₈H₁₈₄O₅N₄S₃, C₂₅₄H₁₇₀O₅N₄S₄, and C₂₇₆H₁₇₉O₅N₄S₄, and the relative molecular mass are 3872, 3482, and 3755. The calculated IR spectrogram is well consistent with that of the experimental results after optimal calculation, and molecular models of thermally dissolution residues were constructed.