In oxy-combustion power plants, flue gas impurities such as NOR must be removed before CO2 recovery. Currently, sorbents or catalysts as well as a flue gas treatment device are required for the application of the traditional NOx control technologies. To produce NOx-lean oxy-fuel-derived CO2, an attractive option is using the existing CO2 compression and purification units (CPUs) as NO removal units instead of traditional selective catalytic reduction technology. The special condition in the CO2 CPU system, high pressure, was one of the most crucial operating parameters for NOx removal in the CO2 compression process. Appropriate pressure along with sufficient residence time of the pressurized denitrification system should be provided to achieve cost-efficient NOx removal. In this work, to simulate the dynamic process of flue gas denitrification at elevated pressures, a two-stage compression process simulation model was built based on the experimental results, and good agreement between experimental and simulated data was obtained. The optimization of the pressure of the compression process as well as residence time showed the feasibility of the system eliminating 94% of NOx with the emission concentration of 48 ppm (100 mg/m(3)) at the optimized pressure of 2.6 MPa and residence time of 223 s. This work demonstrated the possibility of the design and optimization of pressurized denitrification in an oxy-fuel CO2 compression system.