Optical and mass spectrometric study of the pyrolysis gas of wood particles.
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.
Brackmann
Christian
C
Division of Combustion Physics, Lund Institute of Technology, P.O. Box 118, SE-221 00 Lund, Sweden.
Aldén
Marcus
M
Bengtsson
Per-Erik
PE
Davidsson
Kent O
KO
Pettersson
Jan B
JB
D016880:Anisotropy; D029662:Betula / Q000737:chemistry*; D004735:Energy Transfer; D005740:Gases / Q000032:analysis* / Q000737:chemistry; D006358:Hot Temperature; D007834:Lasers; D013058:Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D055095:Optics and Photonics; D010316:Particle Size; D018547:Plant Stems / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000295:instrumentation / Q000379:methods*; D014934:Wood
D005740:Gases