SCR denitration process

1、 Introduction to SCR denitration

SCR (Selective Catalytic Reduction) denitration process adopts liquid ammonia or urea as reducing agent, selectively reacts with nitrogen oxide in flue gas and generates non-toxic and non-polluting nitrogen and water, so as to realize denitration of industrial flue gas.

SCR denitration process is the elimination technology after the generation of nitrogen oxide (NOx), and SNCR denitration process is one of the two major nitrogen oxide control technologies in the world. SCR desulfurization process has low reaction temperature (300-450 ℃), denitration efficiency ≥ 80%, ammonia escape rate ≤ 3ppm, and SO2/SO3conversion rate ≤ 1%. It is a flue gas denitration technology widely used and technically perfect in power plants at home and abroad.

2、 Operating principle of SCR denitration

The flue gas containing nitrogen oxide (NOx) enters the denitration reactor through the economizer. Ammonia gas and diluted air or flue gas are mixed. Under the action of catalyst, ammonia or urea solution and nitrogen oxide have reduction reaction to generate harmless nitrogen and water. At the later stage, the mole ratio of NH3/NOX in the reactor is maintained by adding or replacing new catalyst in the reactor, so as to continuously achieve the required denitration effect.

3、 SCR denitration process flow

Ammonia SCR denitration process:

NO+NO2+2NH3 → 2N2+3H2O

NO+4NH3+O2→4N2+6H2O

NO2+4NH3+O2→3N2+6H2O

Urea SCR denitration process:

NH2CONH2+H2O→2NH3+CO2

NO+4NH3+O2→3N2+6H2O

NO+4NH3→5N2+6H2O

4、 SCR denitration advantages

SCR denitration technology has fast denitration speed, high denitration rate and low ammonia escape;

SCR denitration technology catalyst reaction temperature is low, easy to handle large amount of flue gas, strong processing capacity;

Pihua Technology has designed the control system, which can effectively ensure the stable operation of SCR denitration system.