Abstract It is difficult to directly use Zhundong (ZD) coal because of its high alkali metal content and the associated slagging and fouling problems. Therefore, in this study, hydrothermal (HT) treatment was introduced to remove the alkali metals and upgrade ZD coal at 150–350 °C. The physicochemical structure and gasification characteristics of ZD coal were investigated. The results showed that the properties of the upgraded coal were effectively improved and the coal rank increased after HT upgrading. Additionally, alkali metals Na and K were notably removed, reaching approximately 98% and 82% at 350 °C, respectively. BET analysis indicated that the pore structure was initially enriched at 150–300 °C and then deteriorated at 300–350 °C. The XRD and Raman results revealed that the microcrystalline structure tended to be more aromatic and graphitized, and the chemical structure became dense, orderly and stable. In addition, the CO 2 gasification reaction curve shifted to the high-temperature region as the HT temperature increased. The gasification reactivity exhibited a decreasing trend, and the results were verified by dynamic analysis. Moreover, the comprehensive influence of different factors on the gasification reactivity was explored via a potential mechanism analysis, and a multiple linear regression model of gasification reactivity was established.

中文翻译：

---

水热改质对准东煤理化结构及气化特性的影响

摘要 准东（ZD）煤碱金属含量高，存在结渣和结垢问题，难以直接利用。因此，在本研究中，引入水热 (HT) 处理以去除碱金属并在 150–350 °C 下升级 ZD 煤。研究了ZD煤的理化结构和气化特性。结果表明，HT改质后煤的性质得到有效改善，煤品级提高。此外，碱金属 Na 和 K 被显着去除，在 350 °C 时分别达到约 98% 和 82%。BET 分析表明，孔隙结构最初在 150-300°C 富集，然后在 300-350°C 恶化。XRD和Raman结果表明，微晶结构趋于芳香化和石墨化，化学结构变得致密、有序和稳定。此外，随着HT温度的升高，CO 2 气化反应曲线向高温区移动。气化反应活性呈下降趋势，结果经动力学分析验证。此外，通过潜在机理分析探索了不同因素对气化反应性的综合影响，建立了气化反应性的多元线性回归模型。气化反应活性呈下降趋势，结果经动力学分析验证。此外，通过潜在机理分析探索了不同因素对气化反应性的综合影响，建立了气化反应性的多元线性回归模型。气化反应活性呈下降趋势，结果经动力学分析验证。此外，通过潜在机理分析探索了不同因素对气化反应性的综合影响，建立了气化反应性的多元线性回归模型。