Fossil fuel combustion is an important source of NOx, thus making the control of NO, emissions a primary issue in almost all the developed countries. This paper discusses a post-combustion process for reducing NO, emissions, Thermal DeNO(x), After introducing the general problem of postcombustion technologies for NO, abatement. the relevance of developing reliable kinetic models for a real-size plant design is discussed. Subsequently, some experimental findings are summarized together with the main issues arising from the chemical kinetics of the process. Finally, the influence of some operating parameters, with particular reference to the overall pressure (or concentration), is discussed, showing that there are no kinetic limitations to the efficiency of the process.