The removal of NO from oxy-fuel combustion is typically incorporated in sour gas compression purification process. This process involves the oxidation of NO to NO

2

at a high pressure of 1-3 MPa

followed by absorption of NO

2

by water. In this pressure range

the NO conversion rates calculated using the existing kinetic constants are often higher than those obtained experimentally. This study aimed to achieve the regression of kinetic parameters of NO oxidation based on the existing experimental results and theoretical models.Based on three existing NO oxidation mechanisms

first

the expressions for NO conversion against residence time were derived. By minimizing the mean-square errors of NO conversion ratio

the optimum kinetic rate constants were obtained. Without considering the reverse reaction for NO oxidation

similar mean-square errors for NO conversion ratio were calculated. Considering the reverse reaction for NO oxidation based on the termolecular reaction mechanism

the minimum mean-square error for NO conversion ratio was obtained. Thus

the optimum NO oxidation rate in the pressure range 0.1-3 MPa can be e

xpressed as follows:-d[

NO

]

/d

t

=d[NO

2

]

/d

t

=0:0026[NO

]

2

[O

2

]

-0:0034[NO

2

]

2

Detailed elementary reactions for N

2

/NO/NO

2

/O

2

system were established to simulate the NO oxidation rate. A sensitivity analysis showed that the critical elementary reaction is 2NO + O

2

⇌ 2NO

2

. However

the simulated NO conversions at a high pressure of 10-30 bar are still higher than the experimental values and similar to those obtained from the models without considering the reverse reaction for NO oxidation.