SNCR(選(xuan)擇(ze)性(xing)非催化還(huan)(huan)原(yuan)(yuan)(yuan)法)脫硝技(ji)術，是一種(zhong)經濟實用的NOx脫除技(ji)術,其(qi)原(yuan)(yuan)(yuan)理是以NH3、尿(niao)素[CO(NH2)2]等(deng)作為(wei)還(huan)(huan)原(yuan)(yuan)(yuan)劑，在(zai)注入到(dao)鍋爐(lu)之前(qian)霧(wu)(wu)化或(huo)者注入到(dao)鍋爐(lu)中靠爐(lu)內的熱量(liang)蒸發霧(wu)(wu)化。在(zai)適(shi)宜的溫(wen)度范圍內，氣相的氨(an)或(huo)者尿(niao)素就會分解為(wei)自由(you)基NH3和(he)(he)NH2，在(zai)特定的溫(wen)度和(he)(he)氧存在(zai)的條件(jian)下，還(huan)(huan)原(yuan)(yuan)(yuan)劑與NOx的反應(ying)(ying)優于(yu)于(yu)其(qi)他反應(ying)(ying)而(er)進行。在(zai)較高(gao)的溫(wen)度范圍(850°C~1150°C) 內，還(huan)(huan)原(yuan)(yuan)(yuan)劑(如(ru)氨(an)、CO或(huo)碳(tan)氫化合物等(deng))有選(xuan)擇(ze)性(xing)地(di)將煙氣中的NOx還(huan)(huan)原(yuan)(yuan)(yuan)生(sheng)成為(wei)N2和(he)(he)水(shui)來(lai)減少NOx排放的技術(shu)。

SNCR脫硝系統組(zu)成

SNCR脫(tuo)硝系(xi)(xi)(xi)統(tong)(tong)(tong)主要由氨(an)區（卸(xie)氨(an)、儲氨(an)）、還原劑(ji)輸送系(xi)(xi)(xi)統(tong)(tong)(tong)、計量(liang)/分配系(xi)(xi)(xi)統(tong)(tong)(tong)、噴(pen)射系(xi)(xi)(xi)統(tong)(tong)(tong)、氣源(yuan)站及(ji)其控制(zhi)系(xi)(xi)(xi)統(tong)(tong)(tong)等組成。

SNCR系(xi)統煙氣脫硝過(guo)程(cheng)是由下面四個基(ji)本過(guo)程(cheng)完(wan)成(cheng):

卸料和儲存還(huan)原劑;

在鍋爐合適位注入稀釋后(hou)的還原劑;

還原劑(ji)的計量輸出、與水(shui)混合稀(xi)釋;

還原劑與煙氣混合進行(xing)脫硝反應(ying)。