生物质在惰性及含氧条件下热解特性

EXPERIMENTAL STUDY ON THE CHARACTERISTICS OF BIOMASS PYROLYSIS UNDER INERT AND OXIDATIVE CONDITIONS

在固定床反应器上研究粒径范围为100～150μm的稻秆、玉米秆和杉木屑3种生物质料在不同温度及含氧量中的热解特性,并采用气相色谱/质谱联用仪(GC/MS)分析焦油产物的成分。惰性气氛下的热解实验结果表明:3种生物质在380℃即基本完成其热解过程,此温度下对应的气体产量依次为杉木屑>稻秆>玉米秆,焦炭产量的顺序恰好相反,最大热解焦油生成量(质量含量)分别为:杉木屑为31%,稻秆为25%,玉米秆为22%。测试各焦油中均含有大量含氧类如酚类、酸类和脂类以及少量低环芳烃类物质。对于含氧热解,随热解携带气氛中含氧量增加.焦油产量逐渐减少,气体产量增加,5%的氧气即可降低稻秆和玉米秆约40%的热解焦油产量,而即使15%氧量浓度也仅使杉木屑焦油的产量下降17.4%,可见氧量的增加对稻秆和玉米秆热解焦油产量的影响比杉木屑的更明显。

Pyrolysis characteristic of rice straw, corn straw and fir sawdust biomass in different temperature and ox- ygen concentration have been studied in a fixed-bed reactor, tar was analyzed by gas chromatography/mass spec- trometry （GC/MS）. The results indicated that three biomass pyrolysis process have been completed at 380~C , and achieved the maximum gas yield value in order of fir sawdust 〉 rice straw 〉 corn straw, which is opposite sequence as in char yields. It is also shown that each pyrolysis tar mainly consists of oxygen-containing compounds as phe- nols, acids, ester and small amount of low-aromatic compounds. In thermal oxidative degradation condition, tar yields decreased and gas yields increased when oxygen concentration increasing. However, fir sawdust tar decrease is less sensitive than rice straw or corn straw tar as oxygen concentration increasing, rice straw and corn straw tar was obviously decomposed about 40% as 5% of oxygen present.