DeNOx Nitrogen Oxygen Removal System SNCR
What is the DeNOx Nitrogen Oxygen Removal System?
Let's first understand what nitrogen oxides are!
Nitrogen oxide is a gas mixture of nitrogen and oxygen
Low levels of nitrogen oxides in the air can irritate your eyes, nose, throat and lungs, and severe burns can occur if your skin and eyes come into contact with high levels of nitrogen oxide gas or liquid nitrogen dioxide
The proportion of this type of pollution emitted by vehicles is not high, accounting for about 40% of all pollutants
The proportion of stationary pollution sources is about 30%
It mainly includes power plants, incineration plants, glass and cement plants, and oil refineries.
Selective Non-Catalytic Reduction，SNCR
is the process of removing nitric oxide or nitrogen oxides (NOx) from flue gas. In contrast to selective catalytic reduction (SCR), this method does not use a catalyst to assist, but its purpose is also to decompose nitrogen oxides in flue gas into nitrogen (N2) and water (H2O).
SNCR technology was first used in Japan in the 1970s. The technology is to inject a reducing agent that also contains amino groups (NHx) into the furnace temperature range of 800-1100 °C, and the reducing agent is rapidly pyrolyzed into amonia (NH3) and other by-products.
The denitration efficiency of SNCR is not as high as that of selective catalytic reduction (SCR) technology, but compared with SCR technology, it has the following advantages:
●reduce costs. SNCR technology does not need to change the equipment of the boiler, just add ammonia or urea storage tank, denitration spray gun device and injection port. Moreover, the catalyst does not need to be used in the process, which greatly reduces the use cost.
●The system is simple and occupies less space. The storage tanks for ammonia and urea can be installed on the steel frame of the boiler without requiring additional space.
●Strong usability. SNCR technology is more in line with the current transformation of small and medium boilers. While reaching 60-70% denitration efficiency, it can also save the cost of use.
Because NOx needs high temperature to be removed by the medium, the whole system will have a burner to raise the temperature to above 950 degrees, and the NOx will be removed after the gas reacts. Due to the temperature problem, many thermometers will be installed on the system, and NOx concentration meters will be installed at the inlet and outlet to verify the removal effect.