煤质技术2024，Vol.39Issue(1)：21-28,8.DOI:10.3969/j.issn.1007-7677.2024.01.003
流化床热解试验的褐煤碎裂特性研究
The fragmentation characteristics of lignite during pyrolysis experiment in a fluidized bed
摘要
Abstract
In the process of fluidized bed pyrolysis of lignite,it was easy to break and pulverize to produce dust,which seriously affected the comprehensive utilization of lignite grading processing and utilization.Therefore,it was necessary to study the fragmentation characteristics under the interaction of thermal and mechanical forces,in order to provide data reference for the development of coal conversion and utilization technologies such as pyrolysis,combus-tion,and gasification.Two kinds of lignite from Inner Mongolia were selected to study the effects of particle size,heating temperature,heating rate,residence time and fluidization number on the fragmentation characteristics of lig-nite by using a micro fluidized bed pyrolysis experimental device.The experimental results show that the particle size of semi-coke produced by lignite pyrolysis is mainly distributed in the range of original particle size and low-grade par-ticle size.The particle size change rate and pulverization rate of particles increase with the increase of feed particle size.The increase of final heating temperature and heating rate aggravates the fragmentation degree of coal samples.The extension of residence time will gradually increase the degree of particle fragmentation to stable particle size.The increase of fluidization number will promote particle pulverization and have more obvious influence on fine particle for-mation.In fluidized bed pyrolysis,thermal and mechanical forces are the main and auxiliary forces that generate pul-verization,respectively,the fragmentation form of lignite under the action of thermal force was the spalling of fine particles in the periphery and the internal fragmentation into large particles.By analyzing the semi focal structure at different temperatures through scanning electron microscopy,it can be inferred that,with the precipitation of vola-tiles,the pore structure of semicoke gradually develops,and finally the pore structure was destroyed until collapse and fragmentation due to the effect of agglomeration expansion force and thermal stress.关键词
褐煤/碎裂特性/流化床/热解试验/粒度变化率/粉化率/流化数/半焦孔隙结构Key words
lignite/fragmentation characteristics/fluidized bed/pyrolysis experiment/the change rate of particle size/pulverization rate/fluidization number/pore structure of semicoke分类
矿山工程引用本文复制引用
常赵刚..流化床热解试验的褐煤碎裂特性研究[J].煤质技术,2024,39(1):21-28,8.基金项目
煤科院科技发展基金资助项目(2021CX-Ι-01) （2021CX-Ι-01）
