Different pragmatic approaches have recently been adopted in Paris Agreement of 2015 on the reduction of greenhouse gases, especially carbon dioxide (CO2). A viable option toward reduction of CO2 emission is to couple an exhaust gas fuel reforming reactor to an oxy-combustion power plant for in situ recycling and utilization of unwanted CO2 emission for fuel upgrade. In such a system, steam and dry fuel reforming take place simultaneously with the exhaust gases that are mainly water vapor and carbon dioxide. This study was carried out to explore the advantage of using the gas turbine high exhaust temperature and utilize the unwanted CO2 for fuel upgrade via methane-exhaust gas reforming. A numerical model was developed to study the effect of reforming temperature, gas hourly space velocity (GHSV) and reformer gas ratio (CO2/H2O) on the following performance metrics: methane conversion, fuel upgrade, and hydrogen yield in an exhaust gas-reforming reactor. Results show that the methane conversion increases with decreasing GHSV (i.e., increasing residence time) and approaches its thermodynamic equilibrium at GHSV= 1000 h(-1) Different scenarios were investigated under different reformer gas ratio (CO2/H2O). At low temperature, steam methane reforming is the dominant route for methane conversion. While at high reforming temperature, methane becomes the limiting reactant that is consumed via both steam and dry reforming. Wet exhaust gas reforming with reformer gas ratio (CO2/H2O) of 2.85 has fuel upgrade of about 25% as compared to about 19% obtained in dry exhaust gas reforming. It was further shown that the reformer gas ratio (CO2/H2O) can be manipulated to give the desired syngas ratio (H-2/CO) depending on the application. For reformer gas ratio of 2.85, the syngas ratio obtained is 1.66 at 1073 K, which is suitable for use in Fischer-Tropsch and MeOH/DME synthesis.