The air basin of cities is subjected to considerable pollution, including waste gases generated during the production of thermal and electric energy by power plants. However, power plants are an indispensable element of the life support system on urban areas and they can not be taken out of the city, that means minimizing losses, both material and energy. Therefore, the problem of the correct choice of structural elements and operating characteristics of the process and a system for reducing air pollution is becoming very important. The paper analyzes the most well-known and practical scientific approaches to the selection of optimal measures to reduce air pollution, their advantages and disadvantages are revealed. The authors have singled out the physical and energetic approach as the most acceptable one. The approach is based on the theory of dispersed systems stability, the analysis of the main provisions which allowed us to systematize the parameters of properties, energy parameters and stability of gaseous pollutants formed during the operation of power plants and to construct a scheme for the transformation of gaseous pollutants for the process of reducing air pollution has been performed. At the same time, stability is the resultant criterion characterizing the gaseous pollutants behavior.