CATALYTIC COMBUSTION OF HYDROGEN-AIR MIXTURES OVER PLATINUM: VALIDATION OF HETERO/HOMOGENEOUS CHEMICAL REACTION SCHEMES

The validity of various hetero/homogeneous chemical reaction schemes in the catalytically stabilized combustion (CST) of hydrogen/air mixtures over platinum is investigated experimentally and numerically. The work stems from the internationally intensified effort to commercialize power generation turbines operating with the ultra-low NO x CST technology. Crucial to the development of such systems is the understanding of the heterogeneous (catalytic) and the homogeneous (gas-phase) kinetics. Experiments were performed in an optically accessible catalytic channel reactor and involved planar laser induced fluorescence (PLIF) of the OH radical and line-Raman measurements of major species concentrations. The comparisons between measurements and detailed numerical predictions using elementary, reduced, or one-step mechanisms have revealed substantial differences in the performance of the reaction schemes.