低溫SCR煙氣脫硝催化劑開發(fā)

1、1低溫低溫SCR煙氣脫硝催化劑開發(fā)煙氣脫硝催化劑開發(fā)劉劉 越越浙江大學環(huán)境與資源學院浙江大學環(huán)境與資源學院環(huán)境高技術(shù)青年論壇環(huán)境高技術(shù)青年論壇 ，廈門，廈門， 2010.42煤炭是我國的主要能源煤炭是我國的主要能源年年 度度消耗量消耗量（億噸）（億噸）在一次能源在一次能源中的比例中的比例200617.169.4%20202560%20503350%32.0525.35192.6 探探明明可可采采儲儲量量分分布布Coal 92.6%Oil5.35%Natural gas2.05%我國可持續(xù)發(fā)展必須注重煤炭的高效潔凈利用我國可持續(xù)發(fā)展必須注重煤炭的高效潔凈利用3燃煤是我國主要的污染源燃煤是我國主要

2、的污染源80硫硫 (SO2), 60硝硝 (NOX), 60煙塵煙塵, CO2 等等排放量（萬噸）排放量（萬噸）2000201020200100020003000400050006000NOX 2000201020200100020003000400050006000 SO2 4NOx排放全球分布情況5煙氣脫硝技術(shù)現(xiàn)狀煙氣脫硝技術(shù)現(xiàn)狀NOx控制控制燃燒前燃燒前燃燒中燃燒中煙氣脫硝煙氣脫硝SCR法SNCR法催化分解法催化分解法 等離子體法等離子體法 吸收法吸收法 吸附法吸附法 選擇性催化還原脫硝（SCR）技術(shù)是脫硝效率最高以及應(yīng)用最廣泛的消除煙氣NOx的工藝。 6選擇性催化還原脫硝（選擇性催化還

3、原脫硝（SCR）工藝）工藝7傳統(tǒng)高溫SCR煙氣脫硝工藝 v催化劑體系：催化劑體系：V2O5/TiO2 、WO3-V2O5/TiO2 和和MoO3-V2O5/TiO2 低溫低溫SCR 操作溫度范圍操作溫度范圍353523 K脫硫除塵裝置之后傳統(tǒng)傳統(tǒng)SCR操作溫度范圍操作溫度范圍623673 K能耗較大，易中毒脫硫除塵裝置之前脫硫除塵裝置之前8lMnOxlCrOxlV2O5lCuOlNiO 等lTiO2lAl2O3l活性炭l沸石 等對活性物質(zhì)的保護作用；硫酸根的穩(wěn)定度低溫低溫SCR催化劑的開發(fā)是目前的研究重點催化劑的開發(fā)是目前的研究重點低溫低溫SCR研究現(xiàn)狀研究現(xiàn)狀9低溫低溫SCR研究現(xiàn)狀研究現(xiàn)狀

4、目前低溫目前低溫SCR技術(shù)實現(xiàn)工業(yè)應(yīng)用的瓶頸技術(shù)實現(xiàn)工業(yè)應(yīng)用的瓶頸 低溫下催化活性不夠理想：低溫下催化活性不夠理想： 國內(nèi)電廠和工業(yè)鍋爐大部分采用濕法脫硫技術(shù)，脫國內(nèi)電廠和工業(yè)鍋爐大部分采用濕法脫硫技術(shù)，脫硫后煙氣溫度均低于硫后煙氣溫度均低于80C，目前報道的低溫，目前報道的低溫SCR催催化劑在該溫度段活性不理想。化劑在該溫度段活性不理想。催化劑抗硫性較差：催化劑抗硫性較差： 脫硫后的煙氣中仍含有低濃度的脫硫后的煙氣中仍含有低濃度的SO2，對現(xiàn)有催化，對現(xiàn)有催化劑的毒化作用較明顯劑的毒化作用較明顯10The variation of the NO conversion for the cata

5、lysts prepared by different methodsPublished in “Journal of Hazardous Materials 145 (2007) 488494”MnOx/TiO2The variation of NO conversion with MnOx/TiO2 catalysts with different ratio of Mn/Ti at 423 K90%11Fe-Mn/TiO2Published in “Environ. Sci. Technol. 2007, 41, 5812-5817”55%95%12Fe-Mn/TiO2published

6、 byApplied catalysis B : environmental660655650645640635Fe(0.1)-MnOx(0.4)/TiO2MnOx(0.4)/TiO2 Intensity (a.u)Binding Energy (ev)470468466464462460458456454452450Fe(0.1)-Mn(0.4)/TiO2 Intensity (a.u)Binding energy (eV)Mn(0.4)/TiO2Mn 2p XPS spectraTi 2p XPS spectra 13published by Applied catalysis B : e

7、nvironmentalFe-Mn/TiO214Published by “Environ. Sci. Technol. 2007, 41, 5812-5817”Fe-Mn/TiO2400035002000150010000.00.10.20.30.4Time=30 minTime=20 minTime=10 minTime=5 min Kubelka-MunkWavenumbers (cm-1)Sample with NO+O21580144312901170abcde16031530144012751250400035002000150010000.00.10.20.30.4Time=30

8、 minTime=20 minTime=10 minTime=5 min Kubelka-MunkWavenumbers (cm-1)Sample with NO+O21580144012901275153015551625abcdeFTIR spectra of Mn(0.4)/TiO2 pretreated by exposure to NO + O2 followed by exposure to NH3FTIR spectra of Fe（0.1)- Mn(0.4)/TiO2 pretreated by exposure to NO + O2 followed by exposure

9、to NH315Fe-Mn/TiO2(a)NHOFe(g)NH3323MnOONO+H2O+NH3(a)MnOH-NOO+ONH4+24242NO (a)2NHNO NH +24222NO NH NO2N3H O+2H 第二種反應(yīng)途徑：Published by “Environ. Sci. Technol. 2007, 41, 5812-5817”16SO2氣氛下的反應(yīng)機理Published in “J. Phys. Chem. C”. 17Ce-Mn/TiO2samplesBET Surface Area(m2/g)NO conversion at 90NO conversion at 11

10、0Mn/TiO253.4753.262.1CeMn1/TiO264.1878.0896.4CeMn2/TiO279.7788.7896.8CeMn3/TiO274.8181.4695.6Ce/TiO2115.8122.8727.8Published in “Catalysis communications 9 (2008) 2217-2220”. 18Ce-Mn/TiO2NO conversion of Ce modified MnOx/TiO2 catalysts at different temperatures Published in “Catalysis communications

11、 9 (2008) 2217-2220”. 19Ce-Mn/TiO2H2-TPR profiles for various catalysts. 1-Ce(0)MnTi, 2-Ce(0.07)MnTi, 3-Ce(0.1)MnTi, 4- Ce(0.2)MnTiPublished in “Catalysis communications 9 (2008) 2217-2220”. 20Ce-Mn/TiO2NH3-TPD profiles for Ce(0)MnTi and Ce(0.07)MnTi. Published in “Catalysis communications 9 (2008)

12、2217-2220”. 21Ce-Mn/TiO2SCR activities of Mn/TiO2 and Ce doped Mn/TiO2 in the presence of SO2. Published in “Catalysis communications 10 (2009) 935-939”. 22SEM micrographs of fresh and SO2 poisoned catalysts. (A) MnTi, (B) MnTi-S, (C) MnCeTi, (D) MnCeTi-S. Ce-Mn/TiO2Published in “Catalysis communica

13、tions 10 (2009) 935-939”. 23Ce-Mn/TiO2TG and DSC curves of NH4HSO4 deposited on Mn/TiO2 (A) and Mn-Ce/TiO2 (B) catalysts. Water evaporation Water evaporation NH4HSO4 decompositionNH4HSO4 decompositionPublished in “Catalysis communications 10 (2009) 935-939”. 24X-ray diffraction spectra of Mn/TiO2 an

14、d Ce doped Mn/TiO2 before and after SCR reaction (-Anatase, -Rutile, -MnTiO3, - Ti(SO4)2, -(NH4)2SO4).Ce-Mn/TiO2Published in “Catalysis communications 10 (2009) 935-939”. 25XPS spectra for undoped and Ce doped Mn/TiO2 catalysts before and after SCR reaction in the presence of SO2 (A: Mn 2p, B: Ti 2p

15、). Ce-Mn/TiO2Published in “Catalysis communications 10 (2009) 935-939”. 26Mn-Ce復(fù)合氧化物負載于不同載體Published in “Chemosphere 78 (2010) 1160-1166”. 27Mn-Ce復(fù)合氧化物負載于不同載體Published in “Chemosphere 78 (2010) 1160-1166”. NH3-TPD profiles of Mn-Ce/TiO2 and Mn-Ce/Al2O328Mn-Ce復(fù)合氧化物負載于不同載體Published in “Chemosphere 78

16、(2010) 1160-1166”. 29Mn-Ce復(fù)合氧化物負載于不同載體Published in “Chemosphere 78 (2010) 1160-1166”. 反應(yīng)途徑反應(yīng)途徑2：反應(yīng)途徑反應(yīng)途徑3：反應(yīng)途徑反應(yīng)途徑1：常規(guī)的：常規(guī)的E-R型型SCR反應(yīng)，已被反應(yīng)，已被R.T. Yang等人所報道等人所報道30NO conversions of Mn-Ce/TiO2 in the presence of SO2 at various temperatures. NO conversions of various regenerated Mn-Ce/TiO2 samples. 反應(yīng)溫度