Detailed kinetic calculations have been carried out to evaluate candidate schemes for the removal of NO from combustion gases by injection of compounds leading to homogeneous NHi-NO reactions (i = 2, 1, 0). NO removal is calculated as a function of temperature and reaction time for prescribed initial levels of NO in otherwise equilibrated fuel lean combustion gases. Four different compositions are considered, chosen to include mixtures representative of the Thermal DeNOxProcess (injection of NH3or NH3/H2), as well as alternative mixtures (NH3/H2O2and NH2/CO, the latter chosen to simulate urea) which may have advantages for particular applications, for example in shifting the temperature for optimum NO conversion or in reducing the required reaction time.