ANALYSIS OF WASTE GAS CLEANING METHODS FROM SULFUR DIOXIDE

It is shown that sulfur dioxide is one of the most common components of harmful emissions into the atmosphere. It is presented that a large amount of SO2 is emitted into the atmosphere in the production of sulfuric acid, during the combustion of fuel in thermal power plants, in modern production of surfactants. Sulfur dioxide has been shown to be responsible for the formation of acid rain, which is one of the most common forms of pollution worldwide. The transport of sulfur compounds over long distances leads to the deposition of sulfur dioxide in soils and waterways. It is known that all known methods of waste gas purification are divided into three main groups: ammonia methods, SO2 neutralization methods, catalytic methods. In the general case, absorption methods are divided into open and circulating cleaning schemes. It is shown that ammonia-acid methods are economical, but require the cost of a scarce product – ammonia. The ammonia-sulfuric acid method consists in the treatment of ammonium bisulfite with sulfuric acid. When using the ammonia-phosphorus-acid method, phosphorus methods and sulfuric acid are formed. The soda method is based on the absorption of sulfur dioxide by a suspension of CaO. The lime method is based on the absorption of sulfur dioxide by a suspension of CaO. It is shown that when using a sodium hydroxide solution as an absorbent, both open-loop and circulating cleaning schemes are used. Open circuits are characterized by simple hardware design, as well as low energy for cleaning. It has been shown that catalytic methods for cleaning exhaust gases do not require the use of an absorbent. However, it is necessary to use an expensive catalyst. More often, this method is used at the first stage of cleaning, and at the second – the above methods of cleaning. A table with comparative technical and economic indicators is given. It is shown that for the production of surfactants it is better to use open-loop purification schemes. It is suggested that sodium hydroxide solution can be chosen as the absorbent. With the content of small amounts of sodium sulfite in a solution of sodium hydroxide, it can be used as a neutralizing agent in the neutralization of sulfation products.