Flue gas desulfurization and denitrification in thermal power plants is a very complex and massive system engineering, and its widespread application has brought great challenges and opportunities to the development of China's power enterprises. Due to the enormous and complex nature of this project, a wide range of mechanical equipment will be applied. Except for specific equipment that needs to be imported from abroad, most of the mechanical equipment will be completed by domestic enterprises. In this case, it will also to some extent drive the development of related industries in China and effectively promote the improvement of China's social and economic level. Finally, we can take this as an opportunity to build a professional research team for flue gas desulfurization and denitrification technology, specializing in the development of such technologies. This will not only better realize and develop desulfurization and denitrification technology, but also lay a solid foundation for the development of China's environmental protection industry.
1. The application value of flue gas desulfurization and denitrification technology in thermal power plants
Power generation in thermal power plants mainly relies on combustion, and the degree of fuel combustion can also affect the composition and content of the emitted flue gas. The main substances contained in the exhaust gas emitted by thermal power plants are sulfur dioxide, nitrogen oxides, etc. If these emitted substances are not treated in a timely and effective manner, they will float into the air, causing great pollution to the atmospheric environment and also leading to natural disasters such as acid rain. In addition, the smoke emitted from thermal power plants can pose a threat to human health. At present, there are significant differences in the methods of flue gas treatment among most thermal power plants. Therefore, it is necessary to apply flue gas desulfurization and denitrification technology in thermal power plants. Through the application and research of this technology, environmental protection can be achieved and people's health can be better guaranteed. Promote the further development and growth of thermal power plants
2. Application of flue gas desulfurization and denitrification technology in 3 thermal power plants
2.1 Flue gas desulfurization technology for thermal power plants
(1) Dry desulfurization technology. The technology of adsorbing sulfur dioxide through solid-state catalysts. At present, there are two main dry desulfurization technologies commonly used in China: oxide method and activated carbon adsorption method. The use of dry desulfurization technology can effectively improve the desulfurization rate. The problem is that the substances produced after desulfurization cannot be recovered, which is also a major drawback of dry desulfurization technology.
(2) Wet desulfurization technology. Wet desulfurization technology is exactly the opposite of the dry desulfurization technology mentioned above, which uses liquid catalysts to achieve desulfurization. Compared with dry desulfurization technology, wet desulfurization technology has better desulfurization effect, with a desulfurization rate of up to 90% or even more. It is currently a widely used technology in thermal power plants. Moreover, for wet desulfurization technology, it does not require a large investment cost from thermal power plants, and the material after desulfurization will also be applied. Therefore, it is necessary to focus on the application of this desulfurization technology. At present, there are several commonly used desulfurization technologies in thermal power plants, namely limestone gypsum flue gas desulfurization technology and seawater desulfurization technology. The limestone gypsum flue gas desulfurization technology mainly uses limestone to adsorb sulfur dioxide in flue gas, which does not require a large investment cost. Moreover, the gypsum produced after desulfurization can also be recycled, so its economic effect is very good. The seawater flue gas desulfurization technology mainly adopts the principle of acid-base neutralization, which is the chemical reaction generated by the combination of emitted sulfur dioxide and alkaline gases. For this technology, the application cost is not very high and it is relatively easy to operate, so it has also been widely used.
(3) Flue gas ammonia desulfurization technology. Its biggest advantage and feature is that it can use emissions as agricultural fertilizers, which is very in line with the current situation in China. In the application process, high concentration ammonia water is used as an adsorbent to absorb sulfur dioxide substances, thereby achieving the effect and purpose of flue gas purification. However, at present, this technology has not been applied in thermal power plants in China for two main reasons: firstly, the price of ammonia is relatively expensive, which will increase investment costs; Another difficulty is that the work after desulfurization is very difficult, which will to some extent affect the application and promotion of flue gas ammonia desulfurization technology.
2.2 Flue Gas Denitrification Technology in Thermal Power Plants
(1) SCR denitrification technology. SCR denitrification technology can achieve a denitrification rate of up to 90% in flue gas, and is currently a widely used denitrification technology. Mainly through the reaction between reducing agents and nitrogen oxides in flue gas, non-toxic and pollution-free gases and water are generated, thereby achieving environmental protection. The biggest feature of this technology is that it is very mature and the operation is particularly simple. From the current perspective of the effectiveness of flue gas control in thermal power plants, the application effect of SCR denitrification technology is very obvious, and it is also the most widely used technology.
(2) SNCR denitrification technology. SNCR denitrification technology utilizes
Catalysts and high-temperature boilers are reducing agents containing amino groups that form nitrogen gas, which reacts with nitrogen oxides to ultimately produce nitrogen gas and water. this
Although the cost of this technology is not high and the operation is not very complicated, it still has shortcomings compared to the SCR denitrification technology mentioned above
It is obvious that the denitrification rate is much lower, and the denitrification rate of this technology only reaches 30%, which is still far from the actual requirements.
(3) SNCR-SCR technology. It is a denitrification technology that combines the above two denitrification technologies, mainly utilizing high efficiency
The temperature causes the reducing agent to react with the substances in the flue gas, and then the unreacted substances are put into the SCR reactor to form a catalyst
Reaction. Under the application of this denitrification technology, the advantages of the above two denitrification technologies can be demonstrated, which can not only compensate for SNCR denitrification
The lack of technology can reduce costs and improve denitrification rates, so it has been widely used in thermal power plants.
