摘要
利用层析法对生物质焦油进行分析,比较了不同来源、不同裂化工况处理后焦油族分构成的差异,并对催化裂化过程机理进行探讨。生物质原料组成的不同导致热解焦油构成的差异,木屑焦油中芳香类和极性物的质量分数高于稻杆和稻壳焦油,热解温度越高产生的焦油芳香性越大。催化裂化后,芳香类族分在焦油中的质量分数增长近1倍,其他族分的质量分数出现不同幅度的下降,裂化温度950℃以上时,芳香类的质量分数已达50%。芳香类的转化速度较小,还存在其他族分向芳香类的转化,引起裂化后焦油芳香化程度增大,且这种趋势随焦油转化程度的增大而更为明显。
The influence of biomass tar on the overall thermal chemical process has aroused much more attention with the development of biomass gasification technology. Catalytic cracking is thought to be the most effective route for the solution of biomass tar elimination. However, the variation of tar constitution during the catalytic cracking process, which is most valuable for understanding of the process mechanism, is poorly known, ind of chromatography was used to analyze the constitution of biomass pyrolysis tar, which results in good separation effect and high accuracy. The constitution of tar from different biomass sources and different catalytic cracking conditions was compared, and also the mechanism of catalytic cracking was discussed. On account of the composition of different biomass feedstocks, the content of aromatic and polar fraction in the tar from wood chip pyrolysis is higher than those from rice straw and rice husk. With the increase of pyrolysis temperature, the content of aromatic fraction in tar also increases. After catalytic cracking, the content of aromatic fraction in tar almost doubles, and is 50% with the cracking temperature above 950℃. However, other fractions decrease to different extents. The reason lies in that the reaction rate of aromatic fraction is smaller than those of other fractions, and also there is some conversion from other fractions to aromatic fraction. During catalytic cracking, the constitution of biomass tar has the trend of aromatization, which becomes obvious with the extent of tar conversion.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2005年第5期582-585,共4页
Journal of Fuel Chemistry and Technology
基金
国家杰出青年科学基金(50025618)
国家重点基础研究发展规划(973计划
2004CB719704)。~~
关键词
焦油
生物质
催化裂化
芳香化
tar
biomass
catalytic cracking
aromatization
