The Low NOx technology can be devided into Low NOx combustion and flue gas clean up technolgy. For Low NOx combustion, NOx formation can be suppressed during the combustion process through optimization of combustion conditions; And flue gas clean up technology usually using reducing agents such as ammonia or urea to reduce the formed Nox into N2 and water.

Zhejiang University has originated a completely independent intellectual property rights in SNCR technology and Pallas company is also the first Chinese company finishing SNCR demonstration  . Until now, totally 6 boilers have been finished by the retrafit of SNCR technoly by Zhejiang Universiyt and Pallas company. And 3 feasibility report have been done  , 2 projects in Beijing third thermal power plant, Huzhou Waste incineration power plant have been signed.

Compared with Flue-gas denitration technology of SCR, SNCR technology has its own characteristics and advantages,like less investment and low operating costs etc.

Case:  4×410t/h coal fired boiler of Beijing Co-Generation Branch Company has been  retrafitted since 2006.The Nox emissioins of retrafitted boiler should be controlled under 350 mg/Nm3 according to the contract,. In fact the NOx emission levels always controlled below 300mg/Nm3 .The reduction efficiency can be achieved about 50%. The carbon content in fly ash is as the same level as before ,boiler efficiency has not reduced , the main performance index of boiler can be guaranted and the slagging conditions become better.

SNCR technology has been applied in the mentioned boliers based on the retrafitting of burner in 2007. The actual NOx emission levels has been controlled under 180 mg/Nm3 after the retrafitting.