Denitration equipment | Generation and treatment of nitrogen oxides

Release time:

2022-09-29

Nitrogen oxides come from nature and human industrial production activities. Nitrogen oxides emitted by natural gas come from the decomposition of organic matter in soil and ocean, which belongs to the single cycle of nature. Anthropogenic activities emit NO as a product of complete combustion. When the fuel burns at high temperature, it generates a large amount of nitrogen oxides, such as aircraft, internal combustion engines, industrial kilns, boilers and other processes.

Causes of nitrogen oxides in exhaust gas:

1、 Air factor

In the air, nitrogen accounts for 78% and oxygen accounts for 21%. When the boiler burns, oxygen is required to fully burn. When the combustion reaches high temperature, nitrogen and oxygen in the air react to form nitrogen oxides.

2、 Fuel factor

In the industrial production process, the fuel contains nitrogen element, which reacts with oxygen during its combustion process to produce nitrogen oxides. However, select and burn the temperature to feel the level of NOx production. For example, the nitrogen oxides produced by coal and natural gas will be different. The same fuel will produce different nitrogen oxides when burned at different temperatures. The higher the combustion temperature, the more nitrogen oxides will be produced.

3、 Solution

In order to further solve the problem of enterprises controlling the emission of nitrogen oxides, we control the generator tail gas and NOx generated by boiler combustion. The process method of nitrogen oxides exceeding the standard - selective catalytic reduction (SCR) uses NH3 or urea as the reducing agent. Under a certain temperature and catalysis, NH3 is used to reduce NOx to N2 and H2O. Because NH3 is highly selective, it preferentially reduces NOx without first reacting with O2. In addition, an integrated system that can remove NOx from exhaust gas of internal combustion engine can effectively control NOx emission.

4、 PLC control system

The system is equipped with a general fault alarm lamp and a touch screen alarm prompt function, which can monitor the operation status of core components (urea metering pump, nitrogen oxide sensor). The system collects the exhaust temperature before and after the catalyst, NOx concentration before and after the catalyst, O2 concentration before and after the catalyst, smoke and gas flow, urea tank level, calculates the denitrification rate, and calculates the converted concentration of NOx emission at the outlet.

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