Nitrogen oxides NOx (NO, NO2) are among the gaseous pollutants harmful to the environment and health. Their significant sources include stationary combustion sources up to a rated thermal input of 5 MW. Due to the stricter NOx emission limits applicable since 2019, existing stationary NOx sources will have to respond to these changes by intensifying existing DeNOx technology or installing new technology. The project is focused on the research and optimization of the commercially unrealized catalytic method of NOx reduction consisting in intensification of the action of reducing agents (ammonia, urea, CO) by means of high temperature activated iron compounds (eventually metallic iron), dosed directly into the hot flue gas stream and their subsequent separation. The proposed technology has the potential to achieve lower investment and operating costs over existing SCR NOx units and higher efficiency compared to SNCR NOx. The result of the project will be the design and construction of the DeNOx pilot unit installed at the pilot plant of the VŠB-TUO and the proven technology of the new catalytic NOx reduction method in flue gas.