SNCR(選(xuan)(xuan)擇性非催化還原(yuan)(yuan)(yuan)法)脫硝技術，是一種經濟實用的NOx脫除技術,其(qi)原(yuan)(yuan)(yuan)理(li)是以(yi)NH3、尿素[CO(NH2)2]等作為(wei)還原(yuan)(yuan)(yuan)劑(ji)，在(zai)注入到(dao)鍋爐(lu)之前霧(wu)化或(huo)(huo)者(zhe)注入到(dao)鍋爐(lu)中(zhong)靠爐(lu)內的熱量蒸發(fa)霧(wu)化。在(zai)適(shi)宜的溫度(du)范圍(wei)內，氣相的氨或(huo)(huo)者(zhe)尿素就會分(fen)解(jie)為(wei)自由基(ji)NH3和NH2，在(zai)特(te)定的溫度(du)和氧存在(zai)的條件下，還原(yuan)(yuan)(yuan)劑(ji)與NOx的反(fan)應優于于其(qi)他反(fan)應而進(jin)行。在(zai)較高的溫度(du)范圍(wei)(850°C~1150°C) 內，還原(yuan)(yuan)(yuan)劑(ji)(如氨、CO或(huo)(huo)碳氫化合物等)有選(xuan)(xuan)擇性地將(jiang)煙氣中(zhong)的NOx還原(yuan)(yuan)(yuan)生成為(wei)N2和水來減少(shao)NOx排放的技術。

SNCR脫硝系統組成(cheng)

SNCR脫硝系(xi)(xi)統(tong)(tong)(tong)主(zhu)要由氨區（卸氨、儲(chu)氨）、還原劑輸送系(xi)(xi)統(tong)(tong)(tong)、計量/分配系(xi)(xi)統(tong)(tong)(tong)、噴射系(xi)(xi)統(tong)(tong)(tong)、氣源站及其控(kong)制(zhi)系(xi)(xi)統(tong)(tong)(tong)等(deng)組(zu)成。

SNCR系統(tong)煙氣脫硝(xiao)過程是由下(xia)面四個基本(ben)過程完成:

卸料和儲(chu)存還原劑;

在鍋(guo)爐合(he)適(shi)位(wei)注(zhu)入稀釋后(hou)的還原劑;

還(huan)原劑的計量(liang)輸出(chu)、與水混合稀釋;

還原劑(ji)與煙氣混合進行脫硝反應。