沈阳农业大学学报2017，Vol.48Issue(6)：697-704,8.DOI:10.3969/j.issn.1000-1700.2017.06.009
谷子秸秆的热解特性及傅里叶红外光谱分析
Pyrolysis Characteristics and Fourier Transform Infrared Spectroscopy Analysis of Millet Straw
摘要
Abstract
In order to further explore the process and mechanism of the pyrolysis of millet straw, the pyrolysis characteristics of millet straw were analyzed by thermal gravimetric analyzer (TGA) at 5 (5, 10, 15, 20, 25℃·min-1) different heating rates. The activation energies and their deviations of the millet straw were calculated using Flynn-Wall-Ozawa(FWO) method and Kissinger-Akahira-Sunose (KAS) method at 13 (15%-75%) degrees of conversion. The organic structure of the pyrolysis residue of millet straw was analyzed by fourier transform infrared spectroscopy (FTIR) at different final temperatures (the temperature after hemicellulose reaction, the temperature corresponding to the peak value, the temperature after cellulose reaction). The results showed that the pyrolysis process of millet straw can be divided into four stages, and the pyrolysis trends are similar at the five heating rates, but the thermal hysteresis occurred with the increase of the heating rate. The activation value of the KAS method is 52.93-103.95kJ·mol-1, and the activation value of the FWO method is 54.85-104.31kJ·mol-1. The activation values obtained by FWO method is slightly higher than that of KAS. The difference in the numerical value is because the approximate values selected in the calculation process are different. Although the accuracy of the two methods is different, the activation energies calculated by both methods decrease first and then increase with the increase of the conversion rate. The highest activation energy appears at a conversion rate of 75%, which is in the later stage of pyrolysis reaction, at this time the reaction is relatively difficult, which indicates that lignin decomposition is relatively difficult. The overall trend of the infrared spectra of the millet straw is consistent at the same heating rates and different final temperatures, the position of the absorption peak of the main group changed little, but the intensity of the absorption peak was significantly different. When the final temperature exceeds 400 ℃, some of the individual absorption peaks disappear slowly, at this time, the macromolecular polymer of millet straw has been decomposed into small molecule. The heating rate has little effect on the whole pyrolysis process. At different heating rates, when the final temperature of pyrolysis is similar, the composition of the residue is similar, and the curve of the spectrum is also consistent. This study provides a reasonable scientific basis for the design of biomass pyrolysis reactor.关键词
谷子/热解/动力学/活化能/傅里叶红外光谱Key words
millet/pyrolysis/kinetics/activation energy/FTIR分类
能源科技引用本文复制引用
鄂爽,巴浩楠,马瑞洁,陈东雨,刘璐,高冬笑,黄顺朝..谷子秸秆的热解特性及傅里叶红外光谱分析[J].沈阳农业大学学报,2017,48(6):697-704,8.基金项目
辽宁省自然科学基金项目(2015020648) （2015020648）
