Methane/propane oxidation at high pressures: Experimental and detailed chemical kinetic modeling

Shock tube experiments and chemical kinetic modeling were performed to further understand the ignition and oxidation kinetics of various methane–propane fuel blends at gas turbine pressures. Ignition delay times were obtained behind reflected shock waves for fuel mixtures consisting of CH4/C3H8 in ratios ranging from 90/10% to 60/40%. Equivalence ratios varied from lean (ϕ = 0.5), through stoichiometric to rich (ϕ = 3.0) at test pressures from 5.3 to 31.4 atm. These pressures and mixtures, in conjunction with test temperatures as low as 1042 K, cover a critical range of conditions relevant to practical turbines where few, if any, CH4/C3H8 prior data existed. A methane/propane oxidation mechanism was prepared to simulate the experimental results. It was found that the reactions involving CH3O˙, CH3O˙2, and ĊH3 + O2/HO˙2 chemistry were very important in reproducing the correct kinetic behavior.