PYROLYSIS, OXIDATION AND IGNITION OF C-1 AND C-2 HYDROCARBONS - EXPERIMENTS AND MODELING

The kinetics of the oxidation of natural gas blends (CH4/C2H6) and of ethylene and ethane has been studied in a jet stirred reactor (850 les s than or equal to T/K less than or equal to 1240, 1 less than or equa l to P/atm less than or equal to 10, 0.02 less than or equal to equiva lence ratio less than or equal to 2.0) for the first time. The concent ration profiles of reactants, intermediates and products measured in a JSR have been used to validate a detailed kinetic reaction mechanism. Literature ignition delay times of CH4/C2H6 mixtures measured in shoc k tube have also been modeled as well as shock tube pyrolysis of ethyl ene. A general good agreement between the data and the model is found. The same mechanism has also been used to successfully represent the o xidation of methane, ethyne, ethene, ethane, propene, and propane in v arious conditions including JSR, shock tube and flame. The present stu dy clearly shows the importance of traces of ethane on the oxidation o f methane. The computations indicate that the oxidation of methane is initiated by its reaction with O-2 and by thermal dissociation when no other hydrocarbon is present. However, in the studied CH4/C2H6 mixtur es, ethane reacts before methane leading to the formation of OH, H and O radicals which initiate methane oxidation. The major importance of ethyl radical reactions is demonstrated by the computations.