基于裂解气质联用分析的生物质逐级热解研究

为探究生物质快速热解反应历程,利用裂解气质联用仪对生物质进行逐级热解实验,考察在不同温度区间热解液体产物组分的分布规律。实验结果表明,生物质的化学组成和热解温度区间对热解液体产物都有重要影响。桉木在25℃~400℃热解液体产物较少,主要是吡喃和芳香类化合物,其中5,6-二氢-4-羟基-吡喃-2-酮相对峰面积随温度升高而降低;在450℃~500℃热解液体产物种类和产量均较多,主要以酮类和芳香类化合物为主。玉米芯热解规律和桉木的相似,但在25℃~350℃主要以呋喃类化合物为主,主要热解液体产物是2,3-二氢-苯并呋喃和2-甲氧基-4-乙烯基苯酚,在400℃~450℃热解液体产物以酮类化合物为主。生物质主要化学组分在不同温度区间热解得到不同液体产物,对其进行选择性热解,能够有效实现生物质资源的综合利用。

Step-pyrolysis of biomass using pyrolysis-gas chromatography/mass spectrometry

To study biomass pyrolysis mechanism step-pyrolysis experiments were carried out to investigate the pyrolysis products distribution in different temperature ranges using pyrolysis-GC/MS. The results show that pyrolysis products are deeply influenced by chemical components of biomass and pyrolysis temperature. The liquid yield of eucalyptus pyrolysis within 25℃～400℃ is less, which were mainly pyrans and aromatics. The dominant pyrolysis product of eucalyptus is 5,6-dihydro-4-hydroxy-2H-pyran-2-one which decreases with increasing temperature. However, high liquid yield and more species are generated in 450℃～500℃ in form of ketones and aromatics. Corn cob has the similar pyrolysis property with eucalyptus. However, its liquid products are mainly furans such as 2,3-dihydro-benzofuran and 4-hydroxyl-3-methylacetophenone in 25℃～350℃, whereas ketones are the main products in 400℃～450℃. Different liquid products are produced from the major chemical components of biomass in different temperature ranges. It is possible to carry out a selective pyrolysis for the major chemical components of biomass to achieve efficiently utilization of biomass resource.