摘要
采用热重-红外(TG-FTIR)联用技术研究了煤焦油渣在不同升温速率(8、25、50℃/min)下的热解特性,得到热解反应特征参数;并利用Freeman-Carroll模型对热解过程进行动力学分析。结果表明:升温速率对煤焦油渣热解反应特征参数具有正相关的影响;对于热解过程,热重曲线呈现明显的三段式分布,升温速率对挥发分的总析出量影响不大;适当提高升温速率使热解产物释放更加集中,挥发分释放更加剧烈,热解速率加快;但过高的升温速率则使挥发分短时间集中释放,颗粒内挥发分与煤焦的接触几率增大,促进了二次反应,二次反应产物沉积在煤焦表面,反而使煤焦产率增大;煤焦油渣的热解反应活化能随升温速率的增加而增大,呈正相关性,适宜的升温速率有利于挥发分的析出和二次反应的发生;热解反应动力学参数在整个反应区间线性拟合效果较好,不同升温速率下的活化能和指前因子存在较好的动力学补偿关系。
In order to obtain mechanisms of pyrolysis of coal tar residue and provide directions for its industrial reuse,the thermogravimetric(TG)analysis method was adopted to study the pyrolysis process of coal tar residue under different heating rates,and the characteristic parameters were discussed.Kinetic analysis was performed by employing the Freeman-Carroll method.The results show that heating rate has positive effects on characteristic parameters.For pyrolysis process,TG data fit linearly in three different but continuous regions.Thermogravimetric curves show an obvious three-stage distribution,and heating rate has few effects on total amount of volatiles.Properly increasing heating rate makes the release of pyrolysis products more concentrated,and the release of volatiles more intense,which accelerates the pyrolysis process.However,excessively high heating rate will cause volatiles to be released in short time,increase the contact probability of volatiles in particles with coal char,and promote occurrence of secondary reactions.The activity energy of pyrolysis increases with conversion rate.For pyrolysis process,the data fit linearly quite well over the whole reaction process.At different heating rates,there was a good dynamic compensation relationship between activation energy and pre-exponential factor.
作者
常秋连
CHANG Qiulian(China Coal Technology&Engineering Group Clean Energy Company Limited Department,Beijing 100013,China)
出处
《石油学报（石油加工）》
EI
CAS
CSCD
北大核心
2021年第4期924-931,共8页
Acta Petrolei Sinica(Petroleum Processing Section)
基金
国家重点研发计划项目(2017YFB0602803)
天地科技股份有限公司科技创新创业专项项目(2019-TD-MS011)基金资助
