Optical and Mass Spectrometric Study of the Pyrolysis Gas of Wood Particles
Optical and Mass Spectrometric Study of the Pyrolysis Gas of Wood Particles
复制标题
木颗粒热解气的光学和质谱研究
作者：
C. Brackmann;M. Aldén;P. Bengtsson;K. Davidsson;J. Pettersson
详细的实验研究已取得的热解-生物质燃烧的第一步-单桦木颗粒。除了质谱和重量分析，热解挥发物的特征在于不同的光学技术。吸收测量表明，在紫外光谱区几乎没有特征的吸收，对较短波长的吸收持续增强。使用不同的激发波长，激光诱导荧光测量揭示了在300-500 nm的光谱区域中的一般宽光谱，这是较大烃的特征光谱特征。在颗粒热解过程中的不同时间的光学数据进行了监测，并与质谱和重量分析的结果进行了比较。尽管在吸收光谱和荧光光谱中都可以观察到甲醛，但光学技术用于区分特定分子的灵敏度相当低。激光诱导荧光测量也从加热桦木颗粒发出的热解挥发物的二维可视化，表明更高的流量沿着纤维方向比横跨。
A detailed experimental investigation has been made of the pyrolysis—the first step in biomass combustion—of single birchwood particles. In addition to mass spectrometric and gravimetric analysis, the pyrolysis volatiles were characterized by different optical techniques. Absorption measurements showed a nearly featureless absorption in the ultraviolet spectral region with a continuously stronger absorption for shorter wavelengths. Using different excitation wavelengths, laser-induced fluorescence measurements revealed generally broad spectra in the spectral region from 300–500 nm, which are characteristic spectral signatures for larger hydrocarbons. The optical data were monitored at different times in the pyrolysis process of the particles and compared with the results from the mass spectrometric and gravimetric analysis. The sensitivity of the optical techniques for differentiation between specific molecules was rather low, although formaldehyde could be observed both in absorption and fluorescence spectra. Laser-induced fluorescence measurements were also made for two-dimensional visualization of the pyrolysis volatiles emitted from heated birchwood particles, indicating much higher flows along the fiber direction than across.