摘要
利用热重分析法考察了农作物大豆、高粱、玉米、水稻秸秆及其主要成分半纤维素、纤维素和木质素等以碳酸钠为催化剂时的热解行为 .结果表明 ,秸秆的主要热解区间为 2 0 0℃～ 40 0℃ ,此温度区挥发分析出量约占整个温度区析出量的 80 %～ 90 % .半纤维素、纤维素和木质素 3种组分的热解特性差异很大 ,其中半纤维素热解主要集中在 2 5 0℃～ 340℃范围 ,纤维素在 30 0℃～ 40 0℃范围 ,而木质素的热解发生在一个相当宽的范围内 .热解温度为 60 0℃时 ,纤维素的热解转化率最高 ,半纤维素次之 ,木质素最低 .催化剂使秸秆及半纤维素的主要热解区向低温区间移动 .催化剂的加入可使半纤维素转化率略有提高 ,而对纤维素的作用与对半纤维素的作用正好相反 .催化剂对木质素的影响最为显著 ,其 DTG曲线由无催化剂时的单峰变为一大一小两个峰 ,主要热解区间向低温区移动较大 ,转化率也有所提高 .动力学研究结果表明 :秸秆、半纤维素和纤维素的热解在主要热解区间都可以用单段一级反应过程描述 。
Some typical agricultural wastes, legume, durra, rice and corn stalk, and the main components of biomass, hemicellulose, cellulose and lignin, were pyrolyzed with thermal gravimetric analysis method at different heating rates in the stream of N 2 with sodium carbonate as catalyst, respectively. The Coats Redfern method was used to analyze the pyrolysis process. The results indicate that the pyrolysis of stalks is mainly in the range of 200 ℃ and 400 ℃, and hemicellulose is easy to decompose at low temperature while the conversion of cellulose is the highest of the all. The pyrolysis of lignin covers the widest temperature range. The addition of catalyst makes the pyrolysis of the stalks, hemicellulose and lignin moving to lower temperature range, and improving the conversion but the case for cellulose is quite the reverse. The pyrolysis process of studied stalks, cellulose and hemicellulose can be described with one step first order reaction in the main pyrolysis region, while a two consecutive step first order reaction is best suitable for describing the pyrolysis of lignin.
出处
《煤炭转化》
CAS
CSCD
北大核心
2003年第3期91-97,共7页
Coal Conversion
基金
高等学校博士学科点专项科研基金资助项目 (2 0 0 0 0 14 115 )
关键词
秸秆
组分
催化热解
动力学
热重分析法
agricultural stalk,catalytic pyrolysis, thermal gravimetric analysis,kinetics
