Comparing reaction orders of anthracite chars with bituminous coal chars at high temperature oxidation conditions

Oskar Karlström, Anders Brink, E Biagini, Mikko Hupa, L Tognotti

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    22 Citeringar (Scopus)

    Sammanfattning

    The influence of concentration of oxygen on the oxidation rates of 5 anthracite chars is investigated at gas temperatures ranging from 1223 K to 1673 K. Reaction orders and kinetic parameters are determined with a multivariable optimization method in which modeled burnout profiles are fitted to experimental burnout profiles from a 4 m isothermal plug flow reactor operating at industrially realistic heating rates, i.e., 10(4) - 10(5) K/s. The determined reaction orders are compared to reaction orders of 10 bituminous coal chars investigated at similar conditions in a previous study. The results show that the optimized reaction order of the anthracite chars is zero, while the reaction order of the bituminous coal char is one. The difference in the reaction orders cannot be explained by using the two semi-global oxidation reactions: C(O) + O-2 > CO/CO2 and C(O) > CO. However, by also considering 2C(O) > CO2 + C as a possible reaction step, the reaction order difference between the anthracite chars and the bituminous coal chars can be explained. In addition, a first attempt to apply the same multivariable optimization method to determine the reaction order for a biomass char is presented.
    OriginalspråkOdefinierat/okänt
    Sidor (från-till)2427–2434
    Antal sidor8
    TidskriftProceedings of the Combustion Institute
    Volym34
    Utgåva2
    DOI
    StatusPublicerad - 2013
    MoE-publikationstypA1 Tidskriftsartikel-refererad

    Nyckelord

    • Coal chars
    • Kinetics
    • Reaction order

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