The most serious environmental problem of the chemical industry is the emission of waste gases containing toxic substances, including nitrogen oxides. The chemical industry makes a significant contribution to the progress of the development of our country. The most serious environmental problem of the industry is the emission of exhaust gases containing toxic substances, including nitrogen oxides. The maximum allowable average daily content of nitrogen oxides in terms of N₂O₅ in the atmospheric air of populated areas should not exceed 0.1 mg/m³ while meeting the requirement for a one-time maximum content of nitrogen oxides of not more than 0.3 mg/m³. It is known that in the production of nitric acid the main problem is the emission of nitrous gases and the development of methods to reduce their emission and utilization of these gases.