SelectiveCatalytic Reduction (SCR) technology is act under catalyst agent, reductant NH3(liquid ammonia, ammonia, urea, etc.) the reduction of NOx in fluegas to non-toxic pollution-free ammonia N2 and water H2O.Its reactor is disposed between the boiler economizer outlet and inlet airpreheated, the reaction temperature is generally between 320 ℃ -400 ℃,SCR denitration technology is currently the most mature and reliable domesticand denitration technology, with high efficiency and denitration system issecurity and stability. Reaction principle is as follows:
The main reactionunder aerobic conditions:
4NH3+4NO+O2 → 4N2+6H2O
4NH3+2NO2+O2 → 3N2+6H2O
HO+NO2+2NH3 → 2N2+3H2O
When the reaction conditions are changed, there may occur the followingreaction:
4NH3+3O2 → 2N2+6H2O
2NH3 → N2+3H2
4NH3+5O2 → 4NO+6H2O
Catalyst is thecore and key of the SCR system, the design and selection of catalysts aredetermined by flue gas condition and the components. Factors affecting thedesign of the three interactions are NOx prolapse rate, NH3escape rate and catalyst volume. Mainly in the three forms of plate, bee nesttype and corrugated.
SCR technology ismainly used for coal-fired power boilers, co-generation boilers, centralheating boilers, incinerators, sintering machine, pellet furnace, coke oven,glass kilns, ceramic kilns and other kiln flue gas denitration.
(1)The technology is mature, secure, reliable,with high denitration efficiency andlow operating costs;
(2)Stable operation ,no impact on the main production equipment devices, nosecondary pollution;
(3)Unique denitration for small and medium-scale proprietary technology, a simpleinvestment, operation and management.
Highdenitration efficiency, can reach above 98% according to the requirements ofthe design;
Ammoniaescape rate ≤3ppm; SO2 / SO3 conversion rate of <1%;total equipment resistivity ≤1000Pa;
Afterthe NOx reduction to N2 and H2O, there is nosecondary pollution.