School of Geology and Mining Engineering, Xinjiang University
Petrochina Research Institute of Petroleum Exploration and Development
No.156 Coalfield Geological Exploration Team, Coalfield Geology Bureau of Xinjiang Uygur Autonomous Region

吐哈盆地褐煤的热解和燃烧特性研究利于煤的清洁高效利用及煤炭地下气化的开展,为探究吐哈盆地褐煤煤粉颗粒的热解特性和燃烧特性及动力学特性,通过热重实验、热解特征指数计算、综合燃烧指数计算及动力学软件KineticsNeo模型拟合法,研究了煤粉在不同升温速率(5℃/min,10℃/min,20℃/min)和不同粒径(大于0.8mm,0.2mm~0.6mm,小于0.1mm)下分别在氮气气氛中的热解特性和空气气氛中的燃烧特性,获得了不同条件下煤粉颗粒热解和燃烧过程的动力学参数。结果表明:升温速率升高有利于煤粉颗粒热解和燃烧,显著提升了热解和燃烧性能;煤粉颗粒粒径增大有利于煤粉热解,不利于煤粉燃烧;不同粒径煤样热解和燃烧焦产率没有明显区别,粒径增加对于挥发分释放的影响不大;热解与燃烧过程中活化能与指前因子分别在一次热解阶段和干燥挥发阶段较高,说明在这两个阶段反应速率较慢,单位时间内化学反应程度较高。

The study on pyrolysis and combustion characteristics of lignite in Turpan-Ha-mi Basin is beneficial to the clean and efficient utilization of coal and the development of under-ground coal gasification. Under this background, the kinetic characteristics of pyrolysis and com-bustion of lignite particles in the Turpan-Hami Basin were explored using a combination of ther-mogravimetric experiments, calculation of pyrolysis characteristic parameters and comprehensive combustion indices, and the Kinetics Neo model fitting method. Specifically, the pyrolysis and combustion characteristics of pulverized coal were investigated under various heating rates (5 ℃/min, 10 ℃/min, 20 ℃/min) and particle sizes (more than 0.8 mm, 0.2 mm-0.6 mm and less than 0.1 mm) in both nitrogen and air atmospheres. Based on these, the kinetic parameters of coal pyrolysis and combustion processes under different conditions were obtained. The results indicate that an increase in heating rate enhances the pyrolysis and combustion processes of small coal par-ticles, leading to a significant improvement in their pyrolysis and combustion performance. Meanwhile, the increase in particle size of pulverized coal facilitates pulverized coal pyrolysis, but not conducive to pulverized coal combustion. Besides, there is no significant difference in char yield among coal samples with different particle sizes during the pyrolysis and combustion, and the increase in particle size has minimal impact on the release of volatile matter. Moreover, dur-ing the pyrolysis and combustion of lignite, the activation energy is relatively higher in the prima-ry pyrolysis stage while pre-exponential factor is relatively higher during the dry volatilization stage. This observation suggests that the overall reaction rate in these two stages is slow, and the chemical reaction degree per unit time is high.

国家自然科学基金资助项目(42002188)和中国石油天然气股份有限公司科技重大专项(2019E-25).

白志豪,陈 浩,韦 波,等.吐哈盆地褐煤的热解和燃烧特性及动力学分析[J].煤炭转化,2023,46(5):21-30

DOI:10.19726/j.cnki.eb-cc.202305003.BAI Zhihao,CHEN Hao,WEI Bo,et al.Pyrolysis and combustion characteristics and kinetic analysis of lignite in Turpan-Hami Basin[J].Coal Conversion,2023,46(5):21-30