Multiscale analysis of zhundong coal molecular structure and development of models for clean and efficient utilization
准东煤分子结构多尺度解析与清洁高效利用模型构建

摘要

准东煤作为新疆高挥发分、低灰分煤炭资源的典型代表，其微观分子结构解析有助于其清洁高效利用的定向设计。本研究以准东原煤为对象，采用实验室分析进行多尺度结构解析，在满足元素组成、芳碳率、桥周碳比及表面官能团定量分布的约束下，在现有结构模型研究基础上，构建了一个满足多实验参数约束的“芳香簇—脂肪链—杂原子”平面大分子模型。结果表明：准东煤芳香单元以萘环为主，脂肪部分由亚甲基主链及甲基、次甲基、氧接脂碳组成，边缘含氧官能团以酚羟基和羧基为主，氮主要以吡咯型五元氮杂环形式嵌入芳环体系。该模型在化学位移与键合环境层面均与实验误差<1.5%，可为后续燃烧、热解、气化及沾污行为的反应分子动力学模拟提供可直接调用的结构模板。

Abstract

As a representative of Xinjiang's high-volatility, low-ash coal resources, the microstructural analysis of Zhundong coal facilitates targeted design for its clean and efficient utilization. This study employs laboratory analysis to conduct multiscale structural characterization of raw Zhundong coal. Building upon existing structural models and constrained by elemental composition, aromatic carbon content, bridged-to-peripheral carbon ratio, and quantitative distribution of surface functional groups, a planar macromolecular model incorporating “aromatic clusters-aliphatic chains-heteroatoms” was constructed to satisfy multiple experimental parameter constraints.
Results indicate that aromatic units in Zhundong coal predominantly feature naphthalene rings, while aliphatic segments consist of methylene backbones and methyl, methylene, or oxygen-substituted aliphatic carbons. Peripheral oxygen-containing functional groups are mainly phenolic hydroxyl and carboxyl groups, with nitrogen primarily embedded in the aromatic ring system as pyrrole-type five-membered nitrogen heterocycles. This model exhibits experimental errors <1.5% in both chemical shifts and bonding environments, providing a directly applicable structural template for subsequent reaction molecular dynamics simulations of combustion, pyrolysis, gasification, and fouling behaviors.