The present research shows the combustion characteristics of different specific gravity fractions of high ash thermal coal. Coal with different mean specific gravity (SG_M) ranging from 1.25 to 2.0 was produced using the float–sink experiment. All SG_M coals were characterized with proximate analysis, ultimate analysis, higher heating value, ash analysis, Brunauer–Emmett–Teller analysis and Fourier-transform infrared spectroscopy (FTIR). Combustion experiments were performed with thermogravimetric analysis to identify the impact of SG_M. Experimental results inferred that ignition temperature ranged from 285 to 408 °C as SG_M varied from 1.25 to 2.0. The combustion rate of 1.25 SG_M coal was found to be the highest due to the strong or moderate presence of hydrocarbons like alkane, alkene, aldehyde and alcoholic, as observed from FTIR. Activation energy ranged from 121.81 to 54.60 kJ/ mol as SG_M of coal increased from 1.25 to 2.0. Thermodynamic analysis inferred that 1.65 SG_M coal had the highest ΔS (− 158.21 J/mol. K) and minimum ΔH (48.93 kJ/ mol), inferring ease of decomposition and higher combustion reactivity.

本研究展示了不同比重高灰分动力煤的燃烧特性。使用浮沉实验生产出平均比重 (SG _M ) 范围为 1.25 至 2.0 的煤炭。所有 SG _M煤均通过工业分析、元素分析、高热值、灰分分析、Brunauer-Emmett-Teller 分析和傅里叶变换红外光谱 (FTIR) 进行表征。通过热重分析进行燃烧实验，以确定 SG _M的影响。实验结果推断，当SG _M在1.25 到2.0 之间变化时，着火温度在285 到408 °C 之间。从 FTIR 观察到，由于烷烃、烯烃、醛和醇等碳氢化合物的强或中度存在，1.25 SG _M煤的燃烧率最高。当煤的SG _M从1.25 增加到2.0 时，活化能范围从121.81 kJ/mol 到54.60 kJ/mol 。热力学分析推断，1.65 SG _M煤具有最高的 ΔS（− 158.21 J/mol.K）和最小的 ΔH（48.93 kJ/mol），推断其易于分解且燃烧反应性较高。