The purpose of this study is to show the results of a developed and tested method for the experimental minimization of NOx emissions from a circulating fluidized bed (CFB) in a lignite-fired boiler, which was using the selective non-catalytic reduction (SNCR) method. The paper shows that controlling the spatial distribution of urea and flow conditions in the boiler makes it possible to minimize NOx emissions from a power boiler. In relation to the assumed objective, the scope of the work included among others description of the research power unit, the development of a method for the experimental reduction of NOx emissions in the flue gas under steady-state and transient conditions of the power unit operation, presentation of measurement results and their analysis, determination of the influence of volume flows of air, fuel, urea, sorbent (CaCO3), boiler geometry, spatial distribution of urea, boiler heat load, flue gas temperature, fuel composition on NOx emissions. The method is described in detail in the doctoral thesis [1] of the first author.