摘要
采用热重分析的方法研究了稀酸水解木素在不同升温速率时的热解特性及升温速率对热解反应的影响，并根据微分热重曲线，建立了动力学模型，计算了热解反应的动力学参数．结果表明：200～450℃温度区间是水解木素热解的主要阶段；随着升温速率的增大，热重曲线向高温区移动，升温速率为10、20和30℃／min时，失重速率分别在311．9、323．8和338．1℃左右出现最大值，且微分热重曲线均只出现一个较大的失重峰．根据Coats-Redfern法，稀酸水解木素在不同升温速率下的热解可用两个一级反应表示，随着升温速率的提高，活化能有所降低，低温区稀酸水解木素的活化能在18．27～18．47kJ／mol之间，高温区的在74．45～84．37kJ／mol之间．
The pyrolysis characteristics of lignin hydrolyzed by dilute acid at different heating rates were investigated by means of thermogravimetry, and the effect of heating rate on the pyrolysis was analyzed. Afterwards, a dynamic model describing the pyrolysis process was established according to the differential thermogravimetric curves, and the corresponding kinetic parameters were calculated. The results show that （ 1 ） the pyrolysis mainly occurs at 200 - 450 ℃ ; （ 2 ） with the increase of heating rate, the thermogravimetric curve shifts to the high-temperature range; （3） at the heating rates of 10, 20 and 30 ℃/min, the mass loss reaches the peak value at 311.9, 323.8 and 338.1℃, respectively, with only one obvious mass loss peak occurring at the differential thermogravimetric curves; （4） according to the Coats-Redfern method, the pyrolysis can be described by two first-order reactions; and （5） the activation energy, 18.27 - 18.47 kJ/mol at low-temperature range and 74. 45 - 84.37 kJ/mol at high- temperature range, slightly decreases with the increase of heating rate.
出处
《华南理工大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2009年第6期22-26,共5页
Journal of South China University of Technology(Natural Science Edition)
基金
国家重点基础研究发展计划项目(2007CB210201)
国家自然科学基金资助项目(20576043)
中国科学院可再生能源与天然气水化合物重点实验室基金资助项目(0807K1)
关键词
木素
热解
热重分析
动力学
lignin
pyrolysis
thermogravimetric analysis
kinetics
