Macromolecular structure characterization and its model construction of high-sulfur coal in Jincheng

Abstract

To understand and characterize the structure characteristics of high-sulfur coal at molecular level is of key significance for clean and efficient utilization of high-sulfur coal. The molecular structure of Jincheng high-sulfur coal was characterized by proximate analysis, ultimate analysis, high-resolution transmission electron microscopy, laser desorption time of flight mass spectrometry, 13C nuclear magnetic resonance spectroscopy and X-ray photoelectron spectroscopy. The results show that the aromatic lamellar length of Jincheng high-sulfur coal has a wide distribution range, and the form of 2×2 and 3×3 is the majority; in the heteroatomic structure, the nitrogen atoms are mainly pyridine nitrogen and pyrrole nitrogen, the sulfur atoms exist in the form of mercaptan, thioether, thiophene, sulfoxide and sulfone structures, and the oxygen atoms mainly exist in the hydroxyl group, carbonyl group, and ether oxygen, and the length of the adipose side chain in the structure is short, the degree of branched chain is low. According to the aromatic carbon skeleton information provided by the high-resolution image, 327 aromatic layers were selected as the basic skeleton of the structural model, which was optimized after the addition of aliphatic structure and heteroatomic functional groups in turn. The molecular structure model of high-sulfur coal was obtained in accordance with the above experimental data. The model consists of 95 individual molecules, 18 882 atoms in total. The molecular formula is C12119H6279O214N118S152 and the molecular weight is 161 647 Da. The molecular structure model can be applied to further study the physical and chemical properties and reactivity of high-sulfur coal.

Keywords

• high-sulfur coal
• structure characteristics
• basic skeleton
• macromolecular structure
• molecular structure of model