SNCR-SCR聯(lian)合脫硝工藝,綜(zong)合了(le)SNCR與SCR的(de)技術優勢,揚長避短,在SNCR的(de)基礎(chu)上(shang),與SCR相結(jie)合,可達到(dao)80%以上(shang)的(de)脫硝效率,并(bing)降低運行費用,節省投資。
SNCR脫(tuo)硝原理
SNCR(選(xuan)擇性非催(cui)化還(huan)(huan)(huan)原(yuan))煙(yan)氣(qi)脫硝技(ji)術主要(yao)使用含氮的還(huan)(huan)(huan)原(yuan)劑(ji)在850~ 1150°C溫(wen)度范(fan)圍噴入(ru)含NO的燃燒產物中,發生還(huan)(huan)(huan)原(yuan)反應,脫除NO,生產氮氣(qi)和水。該技(ji)術以(yi)爐(lu)膛為(wei)反應器,目前使用的還(huan)(huan)(huan)原(yuan)劑(ji)主要(yao)是(shi)尿(niao)素(su)和氨水。
SCR脫硝原理
SCR (選(xuan)擇(ze)性催(cui)化還原(yuan)(yuan))脫硝技(ji)術(shu)是(shi)指在催(cui)化劑和氧氣(qi)(qi)(qi)的存在下,在320-427℃溫度范圍下,還原(yuan)(yuan)劑(無水氨、氨水或尿素)有選(xuan)擇(ze)性地與煙(yan)氣(qi)(qi)(qi)中(zhong)(zhong)的NOx反(fan)應生(sheng)成無害的氮和水,從而(er)去除煙(yan)氣(qi)(qi)(qi)中(zhong)(zhong)的NOx,選(xuan)擇(ze)性是(shi)指還原(yuan)(yuan)劑NH3和煙(yan)氣(qi)(qi)(qi)中(zhong)(zhong)的NOx發(fa)生(sheng)還原(yuan)(yuan)反(fan)應,而(er)不(bu)與煙(yan)氣(qi)(qi)(qi)中(zhong)(zhong)的氧氣(qi)(qi)(qi)發(fa)生(sheng)反(fan)應。