基于热重红外联用分析的纤维素热裂解机理研究

Mechanism study of cellulose pyrolysis using thermogravimetric analysis coupled with infrared spectroscopy

在用红外固体压片法研究纤维素多糖结构的基础上，利用热重红外联用技术在线分析研究了纤维素在20K／min升温速率下的热裂解行为．结果表明，纤维素的热分解主要发生在550～670K，680K以后热失重很缓慢，在此温度下固体残留物的质量分数为14．7％．在线红外分析结果表明，纤维素热裂解过程中先析出游离水，随后发生解聚和脱水反应，主要的苷键和碳碳键断开形成各种烃类、醇类、醛类和酸类等物质，随后这些大分子物质二次降解为甲烷和一氧化碳为主的气体产物．

Based on the investigation of the polysaccharide structure of cellulose by using Fourier transform spectrum analysis, the pyrolysis behavior of cellulose was studied at a heating rate of 20 K/min by thermogravimetric （TG） analysis coupled with Fourier transform infrared spectroscopy （FTIR）. Experimental results showed that the decomposition of cellulose mainly occured at the temperature range of 550-670 K. The weight loss became quite slow when temperature increased further up to and above 680 K and the amount of residue finally reached to a mass percent of 14.7%. FTIR analysis showed that free water released out first during cellulose pyrolysis, followed by the depolymerization and dehydration. Glucosidic bond and carbon-carbon bond broke into a series of hydrocarbons, alcohols, aldehydes, acids, etc. Subsequently these large-molecule compounds decomposed further into gases, such as methane and carbon mon oxide.