An experimental and numerical investigation of the catalytic-rich/gaseous-lean combustion of H2/CO/air mixtures at 8 bar

The catalytic-rich/gaseous-lean (R/L) combustion concept was investigated experimentally and numerically for syngas fuels with H2:CO volumetric ratios 1:0, 4:1 1:2, catalytic-rich stoichiometries ?rich = 2–10 (including operation without air), pressure of 8 bar air preheat 673 K. Experiments were performed in a subscale R/L burner optical access to both gaseous-lean stages. OH-PLIF monitored the turbulent stage, OH*-chemiluminescence assessed propensity homogeneous ignition exhaust gas analysis provided NOx CO emissions. Two-dimensional simulations carried out stages, while 1-D opposed-jet code modeled exothermicity heterogeneous reactions promoted flame anchoring upstream parts stage allowed complete consumption deficient O2 reactant, process that could not be achieved by catalytic pathway alone due transport limitations. Homogeneous beneficial attaining highest possible fuel pre-conversion. catalyst only initiated gaseous but also mitigated potential emissions from at pre-conversions (lowest ?rich) CO-content mixtures. Two-sided diffusion flames established recirculation O2-rich products, which advantageous compactness. It shown cardinal fact decreasing led an increased heat transfer bypass air, reduced enthalpy stream thus lowered peak temperatures (by 400 K 1:0). reduction six-fold drop emissions, less than 5 ppmv.