基于热重红外联用分析的纤维素热裂解机理研究

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20 K/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550~670 K,680 K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.

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

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 monoxide.