Catalytic Ignition Properties and Surface Reaction Kinetics Modeling From Methane in Oxygen-Nitrogen Mixtures on Platinum

The ignition temperature and heat generation from oxidation of methane on a platinum catalyst were determined experimentally. A 127 micron diameter platinum coiled wire was placed crosswise in a quartz tube of a plug flow reactor. A source meter with a 4-wire measurement capability measured the resistance and current to calculate the average temperature of the surface reaction. Light-off temperatures varied from 730–780K for methane for a fuel-oxygen equivalence ratio of 0.3 to 1.0 at fuel percentages of 2–5% by volume. A model of the experimental system was created using Fluent coupled with Chemkin to combine an advanced chemistry solver with flow simulation. The experimental data was compared to the model results, which includes heat transfer and the surface reaction kinetics of methane on platinum. The heat transfer model obtained values within 4 Kelvin to experimental data for temperatures between 400K and 700K. At temperatures greater than 700K the model deviated with temperatures greater than the experimental by up to 60 Kelvin.