摘要
COREX炉内加入的块煤会热解并析出焦油,焦油析出包含了热解缩聚反应及分子扩散的不同过程。考虑到在实验室高温条件下煤焦油的析出特点,提出块煤中焦油析出是一个集非等温与等温、化学反应与分子扩散于一体的过程。基于焦油析出初期、中期和后期的理化特点,分别建立了非等温的收缩核模型、一级热解反应模型和反Jander方程描述的分子扩散模型。由此三个模型得到的拟合结果与试验数据均呈现出良好的线性相关性,给出了不同控制过程的时间转换点,验证了模型的合理性。由拟合结果,分别计算了上述控制过程的热解速率常数krea、焦油分子扩散系数D、活化能Ea等动力学参数,为深入研究煤焦油析出过程的机理提供了必要的基础。分段法有很大的普适性,可以应用在其他过程的动力学研究中。
Tar precipitation processes in COREX are usually due to pyrolytic condensation polymerizing reaction and molecular diffusion happened in coal. Based on physical and chemical features of tar precipitation in the initial, middle and last reaction stages, three models including non-isothermal shrinking core model, first order pyrolysis reaction model and molecular diffusion model described by anti-Jander equation were established. The modeling results and experimental data show good linear correlation. The conversion time points of different controlling processes were studied, and the three models were proved to be reasonable. The kinetic parameters such as krea, D and Ea were calculated by the modeling results, which provide a foundation for further study on the mechanism of tar precipitation.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2014年第4期738-744,共7页
Journal of Chemical Engineering of Chinese Universities
基金
国家自然科学基金(51274026)
钢铁冶金新技术国家重点实验室自主研发课题(41603003)
钢铁联合研究基金(50874129
50934007)
关键词
反应过程动力学
分段法
煤焦油
过程动力学参数
反应工程学
kinetics of reacting process
phasewise analysis
coal tar
kinetic parameters
reaction engineering
