紫茎泽兰甲酸和乙酸木素的热解  

Pyrolysis of formic acid lignin and acetic acid lignin isolated from crofton weed stem

作　　者：赵雪冰[1] 刘德华[1] 

机构地区：[1]清华大学化学工程系,北京100084

出　　处：《清华大学学报（自然科学版）》2011年第6期814-819,共6页Journal of Tsinghua University(Science and Technology)

基　　金：科技部国际合作项目(No.2010DFB40170)

摘　　要：为了利用紫茎泽兰这种外来入侵杂草,采用甲酸和乙酸溶液从其茎秆中提取了甲酸木素和乙酸木素,并在不同升温速率下对木素产品进行了差示扫描量热(DSC)和热重(TG)分析。结果表明:这2种木素具有类似的玻璃化温度(Tg),且升温速率对于玻璃化温度的测定无明显影响。2种木素在氮气氛围下的非等温热解过程可分为4个阶段,其中200～450℃为主要热解阶段。进一步的热解动力学研究发现这2种木素的热解反应在主要热解阶段的低温区(200～300℃)为表观1级反应,而高温区(300～450℃)为表观2级反应。Lignin was extracted from the stem of crofton weed,an invasive exotic plant in China,with aqueous formic acid and acetic acid used to obtain formic acid lignin and acetic acid lignin products.The lignins were analyzed by differential scanning calorimetry（DSC） and thermogravimetric analysis（TGA） at different heating rates.The lignins have similar glass transition temperatures（Tg）,but heating rate had no significant effect on the determination of Tg.Four stages were observed for the nonisothermal pyrolysis of the lignins when nitrogen was used as shielding gas.The main pyrolysis stage was found to be 200~450 ℃.Further pyrolysis kinetic studies of the lignins indicated that the thermal degradation of the two lignins can be correlated with a first-order reaction for 200~300 ℃ and a second-order reaction for 300~450 ℃.

关 键 词：紫茎泽兰 甲酸木素 乙酸木素 热解 动力学 

分 类 号：TQ351.37[化学工程]