Time dependent production of NO from combustion of large biomass char particles

Oskar Karlström, Anders Brink, Mikko Hupa

    Research output: Contribution to journalArticleScientificpeer-review

    24 Citations (Scopus)


    In this study, the NO release during the char combustion of single biomass particles was investigated. Cylindrical biomass particles of spruce bark, short rotation coppice (SRC) poplar, Danish straw, and torrefied wood were combusted in a single particle reactor of quartz glass operating between 1073 and 1323 K and with 3-19 vol.% O-2. The initial diameter of the particles was 8 mm. Molar fractions of NO and CO2 were measured at the outlet of the reactor system. During the char combustion stage, the measured molar fractions were converted into time resolved release of NO and carbon from the char particle. To model the NO release from the single char particles, the char-N was assumed to be oxidized to NO proportionally to the experimental carbon release rate. The NO reduction reactions are lumped together such that the reduction rate is modeled as a function of an apparent activation energy, pre-exponential factor, and reaction order. The results showed good agreement between the modeled and experimental NO release rates. Initially most of the formed NO was reduced inside the char particle. As the conversion proceeded, the NO release from the char particles increased although the mass and the diameter of the particle decreased. This is attributed that the fraction of char-N being released as NO increased significantly during conversion. In the final conversion stage, all char-N was released as NO.
    Original languageUndefined/Unknown
    Pages (from-to)524–532
    Number of pages9
    Publication statusPublished - 2013
    MoE publication typeA1 Journal article-refereed


    • Biomass char
    • Combustion
    • Nitrogen oxide
    • Nitrogen oxide destruction
    • Nitrogen oxide formation

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