Modeling of C2 Hydrocarbon Formation from Extremely Fuel-rich Combustion of CH4/air Premixtures using a Micro Flow Reactor with a Controlled Temperature Profile

In order to investigate formation of soot precursors from extremely fuel-rich combustion of methane at low temperature, species measurements of C0-C2 species were performed using gas chromatography connected to a micro flow reactor with a controlled temperature profile. Equivalence ratio of CH4/air mixtures was varied over a range of 1.7-6.0. H2, O2, CH4, CO, CO2, C2H6, C2H4 and C2H2 in exhaust gases were measured at the exit of the reactor with the maximum wall temperature of 1300 K. Detailed chemical kinetics were validated through comparison with experimental results. Chemical kinetic modeling based on AramcoMech 1.3 was conducted mainly focusing on high sensitivity reactions for production of the measured species. Rate constants were modified considering their uncertainties from literature. Validation of the modified mechanism in the present study with the measured species mole fractions were conducted. We confirmed that this modification reasonably improved predictions of mole fractions of the measured species. Especially, mole fraction of C2H4 was quantitatively predicted with the modified mechanism.