Updated chemical reaction mechanism for methane combustion at high pressure

Natural gas continues to be a very important fuel in the present time. Due to its high applicability in different combustion systems research in methane chemistry remains very important. Methane combustion involves a lot of reactions including H2/O2 interactions, carbon containing reactions that lead to CO2 and NOx formation. Many technologies incorporate natural gas and gas turbines in power plants that operate at elevated pressures and lean fuel conditions. The present work aims to analyze existing mechanisms at conditions of high pressure and provide an updated mechanism that also deals with lean fuel combustion. The rate constants of reactions that show sensitivity to such conditions are updated with recently published results. The study focuses on validating the mechanism with experimentally determined laminar burning velocity of CH4/Air mixtures up to 5 atm for equivalence ratio 0.6 to 1.4. Numerical simulations were performed with an in-house flame code using the above mechanism and compared with predictions of two other mechanisms from literature.