没食子酸的热解与燃烧动力学特性研究

Characteristic Study on Pyrolysis and Combustion Kinetics of Gallate

目的对可水解鞣质的有机酸类单体没食子酸进行热解特性及燃烧特性分析,求解相关动力学参数。方法热重分析仪上,在氩气(Ar)气氛下5℃·min-1的升温速率进行没食子酸热解特性研究;模拟空气(N2∶O2=4∶1)气氛下,5℃·min-1、10℃·min-1和20℃·min-1升温速率,对没食子酸进行燃烧特性分析。结果没食子酸的热解分为失水、过渡、快速裂解、炭化四个阶段;没食子酸的燃烧分为失水、过渡、挥发分的释放、固定碳的燃烧四阶段。另外,在模拟空气气氛下,伴随升温速率的不同其燃烧起始温度、挥发分释放温度区间、热失重速率峰极值时所对应的温度及难挥发分及固定炭的燃烧的终止温度、挥发分指数、燃烧指数和动力学计算结果均不同。结论气氛及升温速率均为没食子酸热解过程的重要因素,且没食子酸热解过程符合FC方程模型,线性良好。

Objective To analyze the pyrolysis and combustion characteristics of hydrolyzable tannin organic acid monomer gallate so as to solve the relevant kinetic parameters. Methods Using thermogravimetric analyzer, under argon （At） atmosphere, 5 ℃·min^-1 of heating rate, the pyrolysis characteristics of gallate was studied. Under simulation air（ N2 ： O2 = 4：1 ） ,5℃·min^-1,10 ℃·min^-1 and 20℃·min^-1 of heating rate,the combustion characteristics was analyzed. Results The pyrolysis of gallate included four stages, named water loss, transition, quick cracking and carbonization. The combustion of gallate included four stages, named water loss, transition, volatile release and fixed carbon combustion. Additionally, under stimulation air, with different heating rates, corresponding to the starting temperature, the temperature range of volatile release and the peak value of thermal weight loss rate, the related temperature and the terminal tempera- ture of difficult volatiles and fixed carbon combustion, volatile index, combustion index and kinetic calculation results were all different. Conclusion The atmosphere and heating rate are the key factors of gallate pyrolysis. The gallate pyrolysis is complied with FC equation and presents good linear relationship.