SNCR meansselective non-catalytic reduction denitration technology, that is adopt NH3\ uric and other reducing agent injected into the furnace temperature of 850-1100 ℃ area, reducing agents are rapidlythermal decomposed into NH3 and NOX and selected reactionwith the NOX in the flue gas, NOX is reduced as N2and H2O, this method is based on a stove or furnace reactor, theprocess is simple and easy to operate.
4NO + 4NH3+ O2 → 4N2 + 6H2O
4NH3 +2NO + 2O2 → 3N2 + 6H2O
6NO2 +8NH3 → 7N2 + 12H20
The chemical reactions efficiency that SNCRreduction NO depends on of NO flue gas temperature, residence time at hightemperature, including the type and quantity reducing agent injection , themixing efficiency and the content of NOX in the ammoniacompound and the like.
SNCR systemincludes six parts: storage and transportation of dry uric acid, urea solutionstorage preparation system, circulatory system, SNCR dilution and measurementsystems, distribution systems, injection systems and PCL control systems.
purchasedfinished urea under the action of heat and mechanical stirring at the same time
to dissolve a 50% solution of uric acid, 50%solution of uric acid solution then formulated about 5-10% urea solution bydilution module , into the furnace reaction by the injection module.
SNCR process ismainly used in coal-fired boilers, cogeneration boilers, central heatingboilers, incinerators, sintering machine, pellet furnace, coke oven, glassfurnace and other furnace flue gas denitrification.
(1) Without usinga catalyst, a low one-time investment, less unit area, low investment ininfrastructure;
(2) Lower thanammonia ≤1.3, low operating costs;
(3) Suit afluidized bed boiler and lower emissions reduction project requirements;
(4) Aim at thecoal boiler, can be supplemented SCR + SNCR process.
(1) Aim at Thedenitrification efficiency ≥70%, emissions ≤80mg/ Nm3
(2) lower thanammonia ≤1.3, nitrogen escape rate ≤8ppm