煤热解气体主产物及热解动力学分析

Main gases and kinetics of coal pyrolysis

为了研究不同煤化程度煤的热解气相产物、热解动力参数，采用热重–红外光谱–质谱(TG-IR-MS)联用技术对4种不同热演化程度的煤进行了热解实验。实时记录了4种煤样在30~1100℃、10℃/min升温速率、氦气气氛下热解过程中释放的各种气体成分及其释放量的变化趋势。研究结果表明，随煤热演化程度升高，煤的失重率和最大失重速率逐渐降低，与煤的干燥无灰基挥发分呈正相关关系；随着热解温度的升高，煤中逐渐释放出水、甲烷、二氧化碳、氢气和二氧化硫等小分子气体，且随着煤化程度的升高，各种气体的释放峰逐渐向高温处偏移，说明煤的热稳定性逐渐升高。不同变质程度煤的热解动力学分析结果表明，随着煤变质程度增高，其活化能逐渐降低，说明其热效应强度和发生热解反应的能力在逐渐降低。

In order to study the gas products and kinetic parameters of coal pyrolysis, the pyrolysis experiment was carried out for four coal samples with different thermal evolution using Thermo Gravimetric-Infrared-Mass spectrometry (TG-IR-MS). The variation trend of components and amount of released gases of four kinds of coal samples during pyrolysis at temperature range of 30℃ to 1 100℃ with the heating rate of 10℃/min under helium atmosphere was recorded in real time. The thermal analysis results showed that the weight loss rate and the maximum weight loss rate of coal decreased gradually with the increase of the thermal evolution degree, and was positively related to the voltile of dry ash-free basis. Some small-molecule gases like H2O, CH4, CO2, H2 and SO2 were released gradually with pyrolysis temperature. With the increase of the coalification degree, the peaks of released gases gradually shifted to higher temperature. Pyrolysis kinetic analysis of coals with different coalification degree showed that the activation energy decreased with the metamorphism degree, illustrating that the heat effect strength and the ability of pyrolysis reactions decreased gradually.