COMPREHENSIVE PURIFICATION OF GAS EMISSIONS FROM HEAT POWER PLANTS

Abstract

The article presents a comprehensive scientific approach to solving a pressing environmental problem – cleaning gas emissions of thermal power plants from the most common pollutants: dust, sulfur dioxide, carbon monoxide and nitrogen oxides. The relevance of the study is due to the growth in the volume of emissions of harmful substances and their critical impact on human health and the state of the environment. The proposed technology for cleaning gas emissions consists of four consecutive stages. Dust is cleaned using a cyclone-rotary dust collector, which allows capturing fine dust with an efficiency of up to 99%. For the removal of sulfur dioxide, an absorption method of neutralization is proposed, in which acidic flue gases are cleaned using alkaline wastewater from industrial enterprises. For the removal of carbon monoxide, a catalytic method is proposed. A catalyst composition based on zinc, copper, chromium and aluminum oxides has been developed. Unlike platinum analogues, it can operate in dusty gases and has low hydrodynamic resistance due to the application of a paste-like mass to the inner surfaces of the reactor tubes. The final stage of the complex purification system is the thermal neutralization of nitrogen oxides using an arc plasma torch. The processes of high-temperature decomposition have been studied and it has been established that the introduction of reducing agents, such as methane or ammonia, into the reactor allows to shift the reaction equilibrium towards the formation of molecular nitrogen and oxygen. The proposed step-by-step purification system allows to reduce the concentration of harmful compounds in the purified gases to the maximum permissible values.