The limits to self-sustaining catalytic combustion in a micro-scale channel were studied computationally using a cylindrical tube reactor. Methane-air mixtures with average velocities of 0.0375-0.96 m/sec were used. When the wall boundary condition was adiabatic, the equivalence ratio at the extinction limit monotonically decreased with increasing Re. In contrast, for non-adiabatic conditions, the extinction curve exhibited U-shaped dual limit behavior, i.e., the extinction limits increased/decreased with decreasing Re in smaller/larger Re regions, respectively. Diluting the mixture with N2 rather than oil, the fuel concentration and peak temperatures at the limit decreased substantially for mixtures with fuel/oxygen ratios even slightly rich of stoichiometric due to a transition from O coverage to CO coverage. No corresponding behavior was found for non-catalytic combustion. Exhaust gas recirculation rather than lean mixtures are preferable for minimizing flame temperatures in catalytic micro-combustors. Original is an abstract.
|Number of pages||1|
|Publication status||Published - 2002 Jan 1|
|Event||29th International Symposium on Combustion - Sapporo, Japan|
Duration: 2002 Jul 21 → 2002 Jul 26
|Other||29th International Symposium on Combustion|
|Period||02/7/21 → 02/7/26|
ASJC Scopus subject areas