Mechanism reduction for hetero-/homogeneous combustion of syngas over platinum

Detailed catalytic and gas-phase reaction mechanisms were reduced for the hetero-/homogeneous combustion of H2/CO/ O2/N2 mixtures using the directed relation graph (DRG) method. Simulations were performed in a Pt-coated planar channel using a 2-D steady Navier Stokes code with either detailed or reduced catalytic and gas-phase reaction mechanisms for a wide range of operating conditions. Catalytic and gas-phase reaction mechanisms were treated as a unit and reduced together for fuel-lean and low-pressure fuel-rich cases, while reduced separately for high-pressure fuel-rich cases. The reduced mechanisms well reproduced the major gaseous species concentrations, gas temperatures and homogeneous ignition distances obtained with the detailed mechanisms, thus demonstrating the capacity of DRG in reducing combined catalytic/gas-phase reaction mechanisms. As such, it can provide a quick indication of the important reactions and contributions of both reaction pathways prior to simulations, and is of main interest for large scale simulations used for the design and thermal management of practical catalytic combustion systems.