大城烟煤大尺度热解特性研究

摘要

煤炭地下气化技术能够对煤层进行原位气化,参与反应的煤块来自于煤层的热破碎过程,煤块尺度大.为研究大尺度块煤的热解特性,对大城烟煤进行CO2和N2气氛下.尺度为5cm.8cm.10cm的热解实验.结果表明:不同气氛与尺度对热解活化能无明显影响,以外温为基础时热解反应活化能为120kJ/mol左右,以内温为基础时活化能为50kJ/mol左右;随着尺度的增加,热解所得有效气体组分升高;增加热解反应停留时间可以增加热解反应效率;CH4的逸出从300℃开始持续增加,N2气氛下CH4含量在700℃达到峰值,CO2气氛下则继续上升.H2的逸出均从500℃以上开始,并且随着温度的升高,在N2气氛与CO2气氛下热解过程中,在700℃.750℃时,H2释放量达到最大值.%Coal underground gasification technology can realize coal seam in-situ gasification,the large size lump coal participates the reaction comes from the thermal crushing process of the coal seam.In order to study the pyrolysis characteristics of large size lump coal,pyrolysis experiment was carried out with 5cm,8cm and 10cm lump coal in the atmosphere of CO 2 and N 2.The results show that the activation energy of pyrolysis is about 120kJ/mol when the temperature is based on the external temperature,and it is about 50kJ/mol on the internal temperature;with the increase of coal size,the effective gas components increase;the pyrolysis efficiency increases with pyrolysis reaction residence time;the CH 4 emission starts to increase at 300℃,and reaches the peak at 700℃ in N 2 atmosphere,while it will continue to increase in CO 2 atmosphere.The H 2 emission is above 500℃ and reaches the maximum value at 750℃ and 700℃,during the pyrolysis in N 2 and CO 2 atmosphere of with a rising temperature.