適用范圍：水泥、鋼鋼、電力、化工、冶金等行業。

定義：SNCR:選擇性非催化還原技術SNCR是向爐窯合適部位噴入氨基還原劑，在850~1100°C的溫度條件下,與煙氣中的N0x發生還原反應，形成無害的Nz和H20,脫硝效率30~70%。還原劑主要以
尿素、氨水為主。主要用于水泥、鋼鐵、電力、化工、治金等行業。SCR: SCR和SCNR不同的是，反應過程中有了催化劑的參與，催化劑的參與降低了反應溫度至
300~380°C，并提高了反應效率?；旌蟂NCR-SCR:混合SNCR-SCR煙氣脫硝技術是結合了SCR技術高效、SNCR技術投資省的特點而發展起來的一種新型工藝。

工藝流程：SNCR:SNCR工藝就是把含有氨基的還原劑噴入到鍋爐爐膛中850~1100°C的區域內，該還原劑快速熱解成NH3并和煙氣中的NOX進行還原反應，將N0x還原成Nz和H20。SCR:采用氨氣或無水液氨作為還原介質,把符合要求的氨氣噴入煙道中,與原煙氣充分混合后進入反應塔,在催化劑的作用下，并在有氧氣存在的條件下，選擇性地與煙氣中的NOx發生反應,生成N2H20?；旌蟂NCR-SCR:混合SNCR-SCR工藝具有兩個反應區，通過布置在鍋爐爐墻上的噴射系統，首先將還原劑噴入第一個反應區--爐膛，在高溫下，還原劑與煙氣中的N0x發生非催化還原反應,實現初步脫氮.然后，未反應完的還原劑進入混合工藝的第二個反應區--反應器,進-步脫氮.

工藝優點：SNCR:具有 最大靈活性，系統簡單，施工周期短，可以根據運行狀況靈活處理，不受機組燃料和負荷的變化影響。SCR:脫硝效率最高，可達50~85%，但投資較高。
混合SNCR-SCR :脫硝效率高，催化劑用量小，反應塔體積小、空間適應性強,脫硝系統阻力小，降低腐蝕危害,省去SCR旁路，催化劑的回收處理量減少，簡化還原劑噴射系統，提高SNCR階段的脫硝效率，方便地使用尿素作為脫硝還原劑，減小N20的生成，降低由于煤種引起催化劑大量失效的壓力。

Socope:Cement, steel, power, chemical, metallurgical and other industries.

Definition:

SNCR: Selective non-catalytic reduction technology SNCR is to provide a suitable site within the kiln, from which is injected in to the amino reductant. At the temperature of 850-1100C，reduction reaction occurs between amino reductantand NOx in the flue gas, then generates harmless N2 and H2O, the denitrification efficiency is from 30 to 70%. Reductant mainly composes of urea and ammonia

SCR: SCR is different with SCNR, With the participation of the catalyst during the reaction leads to a reduction.in the reaction temperature to 300~ 380C, and improving the reaction efficiency.
Hybrid SNCR-SCR: Hybrid SNCR-SCR flue gas denitrification technology is a new developed process which has combined the characteristics of SCR technical efficiency and SNCR technology investment savign.

Process:

SNCR: SNCR Process sprays the reductant which contains amino into the boiler furnace at the temperature of 850~1 100C region, The reductant Pyrolyzes quickly into NH3, and reduction reaction occurs between NH3 and NOx in the flue gas, the NOx dioxides into N2 and H2O.

SCR: Using ammonia or anhydrous ammonia as a reducing medium, to meet the requirements of ammonia injected into the flue, and after mixing with the orininal gas goes into the reaction tower In the of a catalyst and in the presence of oxygen, ammonia reacts witrh NOx in the flue gas selectively, then generates N2 and H2O.

Hybrid SNCR-SCR: Hybrid SNCR-SCR Process has two reaction zones. First, through the injection system which arranges on the wall of the boiler furnace, the reductant is sprayed into the first reaction zone--Furnace. At high temperatures, non-catalytic reduction reaction occurs between reductant with NOx in the flue gas, achieves preliminary denitrification. Then, the unreacted reductant goes into the mixing process of the mixing process of the second rdaction zone -Reactor ,further denitrification occurs.

Process Advantages:

SNCR: It has maximum flexibility, simple system, short construction period, It can depend of the operating Conditions flexibly and it isn't affected by unit fuel and load changes.

SCR: It has the highest denitration efficiency up to 50~ 85 %, however, the investment is higher.

Hybrid SNCR-SCR: Higher denitrification efficiency, small amount of catalyst, small reaction toewr, space adaptable, deitrification system small resiatance, reduce the corrosion hazard, eliminate SCR bypass, reduce catalyst recovery process, simplify the reductant injection system, iumprove the efficiency of denitrification in SNCR stages, easy to urea as a reductant for denitrification, reduce the production of N2O, reduce stress from coal causes catalyst amount of failure.