Denitrification is a technology that reduces nitrogen oxide (NOx) emissions from coal-fired power plants, industrial boilers, and other combustion processes. These emissions have a negative impact on the environment and human health, so measures need to be taken to reduce their release. The denitrification equipment is one of the important equipment used to achieve this goal, and the following will introduce the common denitrification equipment.
1.Selective Catalytic Reduction (SCR).SCR is a common denitrification technique that converts NOx into nitrogen and water by injecting an ammonia or urea solution into the flue gas and reacting it with a catalyst. SCR systems typically include a catalyst, an ammonia injection system, and a catalytic reactor.
2.Non-selective catalytic reduction (NSCR).NSCR is another common denitrification technique that is similar to SCR, but does not require strict chemical reaction conditions. NSCRs typically employ ammonia or urea as reducing agents and convert NOx into nitrogen and water through catalysts.
3.Selective non-catalytic reduction (SNCR).SNCR is a catalyst-free denitrification technology that reduces NOx emissions by injecting a reducing agent, usually ammonia or urea, directly into the flue gas at high temperatures. This method is usually used when the flue gas temperature is above 800°C.
4.Ammonia Injection: Ammonia Injection is a method of injecting ammonia directly into the combustion chamber or flue gas to react with NOx to form nitrogen and water. This method is commonly used in large-scale combustion equipment in industrial boilers and coal-fired power plants.
5.Low Nox burners: Low-nitrogen combustion technology reduces NOx emissions from combustion by optimizing the combustion process. This technique includes methods such as changing fuel injection, changing burner design, and optimizing combustion air distribution.
6.NOX absorption: Nitrogen oxide absorption is a technique that adsorbs NOx onto an adsorbent and removes it from flue gases. Commonly used adsorbents include activated carbon, calcium oxide, and sodium hydroxide.
7.Nox oxidation: NOx oxidation is a technology that converts NOx to NO2, thus making subsequent denitrification easier. This method typically uses oxidizing agents such as ozone or hydrogen peroxide.
These denitrification technologies can be applied individually or in combination to achieve higher denitrification efficiency. Choosing the right denitrification plant usually depends on the type, size and operating conditions of the combustion plant, as well as the stringency of NOx emissions and the requirements of environmental regulations.