### Methane-Air Reaction Mechanism (GRI-Mech 3.0)

In this sample, the methane-air reaction mechanism from GRI-Mech 3.0 [1] is used. The mechanism consists of 325 reactions that involve 53 species. The three following problems were solved to compare our results to independent calculations of other authors.

#### NO Emission in Methane Oxidation

Parameters of this problem are similar to that studied in [2]. We don’t concern about the main subject of the work [2] (creating a reduced reaction mechanism for NO emission) and take only the numerical data for NO reburning. A fixed pressure problem is solved.

Input values

Pressure: 1atm

Temperature: 1300K or 1600K

Table 1. Initial mole fractions

CH4 | C2H6 | O2 | NO | H2O | N2 |

2.864E-03 | 2.98E-04 | 5.09E-03 | 9.47E-04 | 2.16E-02 | 0.9692 |

Solution

Fig 1. Comparison of calculated profiles: points – data from [2], lines – Chemked calculation.

#### Thermal decomposition of CH2O at fixed pressure and fixed temperature (from the GRI-Mech collection)

Conditions of this calculation correspond to the experiments [3].

Input values

Temperature: 1805K

Mole fractions: [CH2O]: [AR] = 4 : 96

AR concentration : 1.9E-05 mole/cm^{3}

Solution

Fig 2. Normalized CH2O profile: circles – experimental data [3], line – calculation [1], crosses – Chemked calculation

#### Oxidation of methane at fixed pressure and fixed temperature (from the GRI-Mech collection)

Conditions of this calculation correspond to the experiments [4].

Input values

Pressure: 1atm

Temperature: 2454K

Mole fractions: [CH4]: [O2]: [AR] = 0.1 : 0.4 : 99.5

Solution

Fig 3. Mole fraction of CH3:

black line – experiments [4], green line – calculation [1], crosses – Chemked calculation

#### References

[1] GRI-Mech 3.0, The Gas Research Institute,

http://www.me.berkeley.edu/gri_mech/

[2] C.J.Sung, C.K.Law, and J.-Y.Chen. Augmented Reduced Mechanisms for NO Emission in Methane Oxidation. Combustion and Flame, 125, p.906 ( 2001).

[3] Y. Hidaka , T. Taniguchi, H. Tanaka, T. Kamesawa, K. Inami, and H. Kawano. Shock-Tube Study of CH2O Pyrolysis and Oxidation, Combustion and Flame, 92, p. 365 (1993).

[4] A.Y. Chang, D.F. Davidson, M. DiRosa. R.K. Hanson, and C.T. Bowman. Shock Tube Experiments for Development and Validation of Kinetic Models of Hydrocarbon Oxidation, 25th Symposium (International) on Combustion, Poster 3 - 23 (1994).