关键词: Macromolecular model of coal, Spectral simulation, Reaction molecular dynamics, Coal gasification

Abstract: Understanding the structure of coal is helpful to understand the diverse reactivity of coal at a molecular scale and offer support for clean and effective utilization of coal. The physical properties of a typical coal from east of Ningxia were characterized by some analysis methods such as elemental analysis, FT-IR, XPS, and ¹³C NMR. And the key parameters of the microstructure of the coal sample were obtained such as the type, valence and chemical bond and so on. The molecular composition of coal has been established as C₂₀₂H₁₅₃O₃₈N₃S₂, and a three-dimensional representation of its molecular structure was created. The molecular dynamics approach utilizing reactive force fields was employed to model the process of coal gasification. The influence of reaction force fields and temperature on coal gasification process were investigated, and the main small molecule products in different atmospheres were tracked. It was indicated that the consumption and consumption rate of raw coal and the production of primary products increased with increasing of the temperature. All carbon elements in coal were converted into fragments with less than three carbon atoms at the H₂O atmosphere and 3500 - 4000 K, and the C₁ content can reach 97.73% at 4000 K. It was proved indirectly that the gasification reaction process had been completed. In mixed atmospheres, the gasification condition closest to industrial scenarios was 500H₂O + 1500CO₂, yielding a CO/H₂ ratio of 3.52, matching actual outcomes. Molecular dynamics simulation of gasification process based on coal macromolecules is conducive to reveal gasification reaction mechanism.

Key words: Macromolecular model of coal, Spectral simulation, Reaction molecular dynamics, Coal gasification