1 / 30

by Chen Zhi-hang Ph.D. Atmospheric Environment & Pollution Prevention Research Center

复合氧化物在催化脱硝领域中的研究及应用 Research & Application of Mixed Oxides for Selective Catalytic Reduction of NO x. by Chen Zhi-hang Ph.D. Atmospheric Environment & Pollution Prevention Research Center South China Institute of Environmental Science, MEP. Contents. Introduction

zuwena
Download Presentation

by Chen Zhi-hang Ph.D. Atmospheric Environment & Pollution Prevention Research Center

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 复合氧化物在催化脱硝领域中的研究及应用Research & Application of Mixed Oxides for Selective Catalytic Reduction of NOx by Chen Zhi-hang Ph.D. Atmospheric Environment & Pollution Prevention Research Center South China Institute of Environmental Science, MEP

  2. Contents • Introduction • Mixed-oxideCatalysts for Industrial Boiler at High Temperature • Mixed-oxideCatalysts for SCR at Low Temperature • Mixed-oxideCatalysts for Glass Kilns at Middle-low Temperature • Conclusions & Prospect

  3. Transportation Power Plant Others Introduction NOx emission Beijing Frequency Area% <5% 67.4% 5~10% 6.8% 10~25% 10.4% 25~50% 8.2% 50~75% 5.4% >75% 1.8% No data Nitrogen oxide emissions from power plants, industrial boilers, and kilns accounted for 70% in China. (Journal of Environmental Sciences, 2008, 28(12): 2470-2479) Shanghai Acid Rain Distribution in China Guangzhou

  4. Technology for DeNOx Adsorption Method SNCR • Commercialized • High efficient NH3-SCR NH3 Plasma Method SCR DeNOx SCR Reaction: Microbial Process Electrolytic Process SCR——selective catalytic reduction SNCR——selective Non catalytic reduction

  5. Mixed-oxideCatalysts for Industrial Boiler at High Temperature

  6. SCR for flue gas denitrification in power plant boilers Honeycomb Corrugated plate Flat SCR DeNOx Reactor in power plant boilers. SCR V2O5-WO3(MoO3)/TiO2 The process flow diagram of SCR denitrification in power plant boilers.

  7. Flue gas denitrification pilot test ——Small and medium-sized boiler The honeycomb SCR catalyst developed by Tsinghua University et. al. Test device for flue gas denitrification(200 Nm3/h) • National High Technology Research and Development Program of China(2006） • Guangdong-Hongkong Project of The Major Breakthroughs in Key Areas（2008） • Major Scientific and Technological Special Project of Guangdong Province (2010）

  8. SCR DeNOx Reactor Demonstration projects of SCR——Industrial boiler Demonstration projects of SCR denitrification (35 t/h chain-grate boiler in Pacific(Panyu) Textiles Limited, flow rate: 70000 Nm3/h ) SCR Denitrification tower of Pacific co.

  9. Mixed-oxideCatalysts for SCR at Low Temperature

  10. SCR at Low Temperature SCR SCR at 80~150℃ • Energy efficient and cost saving • Typical SCR catalyst has low activity under low temperature • Novel Catalyst should be developed for low temperature • Suitable temperature for catalysis(SCR at 350~450℃) • Dust (e.g., K2O, CaO, and As2O3) and SO2 deactivate the catalyst

  11. Catalysts Developed for Low-Temperature SCR[1~12] • MnOx、MnOx/TiO2、CuOx-MnOx and MnOx-CeO2 etc.. • Mn-Cu/TiO2、Mn-Cr/TiO2 catalysts showed good activity (CNO: 60％, 120oC, NO/NH3 =1 at 0.2%, GHSV=8,000 h-1) • MnOx-CeO2 exhibited well activity(100oC, CNO:~90%, NO/NH3 =1 at 0.2%，GHSV=42,000 h-1) • Sulfur dioxide and vapour resistant are weak. • Mixed-oxide catalyst may be a kind of prospective low-temperature SCR candidates [1] Catal. Commun. 8 (2007) 2096. [2] Appl. Catal. A 327 (2007) 261. [3] Catal. Commun. 8 (2007) 329. [4] Appl. Catal. B 79 (2008) 347. [5] Catal. Commun. 8 (2007) 1896. [6] Angew. Chem. Int. Ed. 40 (2001) 2479. [7] Appl. Catal. B 44 (2003) 217. [8] Catal. Today 111 (2006) 236. [9] Appl. Catal. B 51 (2004) 93. [10] Appl. Catal. B 62 (2006) 265. [11] Chem. Commun. 7 (2003) 848. [12] Ind. & Eng. Chem. Res. 45 (2006) 6444

  12. Screen of Low-temperature SCR Catalysts Activity of mixed oxides prepared by SR method Activity evaluation conditions:[NO]=[NH3]=1000 ppm[,O2]=3%,[SO2]=100 ppm,GHSV=30,000 h-1 • Cr-MnOx、Fe-MnOx are potential catalysts

  13. Cr-MnOx SCR activity at Low temperature New crystal SCR activity and XRD patterns of (a) CrOx; (b) MnOx; (c) CrOx-MnOx; (d) Cr(0.5)-MnOxcatalysts

  14. Cr(0.4)-MnOx Cr(0.5)-MnOx Cr(0.4)-MnOx Cr(0.3)-MnOx Cr(0.3)-MnOx Cr(0.2)-MnOx Cr(0.2)-MnOx Cr(0.1)-MnOx Cr(0.1)-MnOx XRD patterns and SEM images of the Cr-MnOx catalysts doped by different Cr content

  15. Mechanism studying ——Cr-MnOx Structure analysis MnO Mn3O4 Cr2O3 CrMn1.5O4 Bond length of crystals • Oxygen bridge between Cr and Mn in the form of Cr-O-Mn; • Cr-O bond in CrMn1.5O4 is shorter than those of CrOx • Mn-O bond in CrMn1.5O4 is longer than those of MnOx Cell of CrMn1.5O4

  16. Mechanism studying ——Cr-MnOx Raman spectra measurement • Raman shift of CrOx in lower wave number without presenting in mixed oxides conforms the formation of new phase; • New Raman shift appears and increases with the increasing of Cr content; • Raman shift at 539.3 and 642.7cm-1 are the characteristic shifts of Cr-O-Mn in CrMn1.5O4 Cr(0.5)-MnOx Cr(0.4)-MnOx Cr(0.3)-MnOx Cr(0.2)-MnOx Cr(0.1)-MnOx Mn3O4[16-18] Cr2O3[13-15] MnOx CrOx [13] J. Appl. Phys. 99 (2006) 053909; [14]Mater. Sci. Eng. B 118 (2005) 74; [15] J. Appl. Phys. 103 (2008) 023507; [16] J. Electrochem. Soc. 140 (1993) 3065; [17]J. Mater. Chem. 11 (2001) 1269; [18] J. Catal. 150 (1994) 94 Raman spectra of catalysts

  17. Mechanism studying ——Cr-MnOx XPS measurement Mn 2p Cr 2p O 1s regenerated used fresh XPS spectra for (A) Mn 2p, (B) Cr 2p, and (C) O 1s of the Cr(0.4)-MnOx catalysts: (a) fresh catalyst, (b) used catalyst, (c) regenerated catalyst.

  18. 10.6% 9.0% Cr5+ Cr5+ 7.3% Mn3+ 13.7% Mn3+ 7.7% 11.9% Cr3+ Cr3+ 6.4% Mn4+ 14.2% Mn4+ Mechanism studying ——Cr-MnOx XPS measurement Binding energies (eV) of core electrons of Cr(0.4)-MnOx catalysts* After 500h SCR Regenerated catalyst Normal pressure & temperature plasma treatment * Surface concentration of different Mn, Cr and O states are in parenthesis

  19. Mechanism studying ——mechanism elucidation Redox catalytic cycles over Cr(0.4)-MnOx catalysts Journal of Catalysis, 2010, 276: 56-65. Industrial & Engineering Chemistry Research, 2012, 51: 202-212. Industrial & Engineering Chemistry Research, 2014, 53: 2647–2655.

  20. Pilot test of Low-temperature SCR The Low-temperature SCR catalyst developed by Research Center for Eco-environmental Science, CAS et. al. Test device for Low-temperature SCR (Circulating fluidized bed boiler in Guangzhou Huiteng Textiles Limited, flow rate: 5000 Nm3/h ) • National Natural Science Foundation of China（2008） • National High Technology Research and Development Program of China(2009）

  21. Mixed-oxideCatalysts for Glass Kilns at Middle-low Temperature

  22. Middle-low temperature SCR for glass kilns • Middle-low temperature SCR • Work at 180~300℃ • High activity • Strong ability of sulfur tolerant The flue gas emission from glass kiln of China South Glass Group(Guangzhou) (The concentration of SO2、NOxis very high(about 500~3000mg/m3) The temperature of flue gas is low(＜ 280℃) The process flow diagram of SCR for glass kiln.

  23. Screen of Middle-low Temperature SCR Catalysts SCR activity of VM/TiO2 catalysts

  24. Effect of SO2 Effects of SO2 on NOx conversions over VM/TiO2 catalysts at 275oC. Reaction conditions: [NO]=[NH3]=1000 ppm, [O2]=3%, [SO2]=600 ppm, GHSV=60,000 h-1

  25. XPS measurement 2V20Cu/TiO2 V4+ 2V16Cu/TiO2 2V12Cu/TiO2 2V8Cu/TiO2 V5+ 2V2Cu/TiO2

  26. VCuMn/TiO2 & VCoMn/TiO2 Catalysts VCoMn/TiO2 VCuMn/TiO2 SCR activity of VCuMn/TiO2 & VCoMn/TiO2Catalysts

  27. Effect of SO2 VCoMn/TiO2 VCuMn/TiO2 Effects of SO2 on NOx conversions over VCuMn/TiO2 & VCoMn/TiO2catalysts at 250oC. Reaction conditions: [NO]=[NH3]=1000 ppm, [O2]=3%, [SO2]=600 ppm, GHSV=60,000 h-1. Advanced Materials Research, 2012, 550-553: 128-131. Journal of Fuel Chemistry and Technology, 2012, 40(4):469-474.

  28. Forming of Catalysts The vacuum refining mud machine Hydraulic extruder • Natural Science Foundation of Guangdong (2011） • National Natural Science Foundation of China （2013） • Pearl River Nova Program of Guangzhou (2014）

  29. Conclusion & Prospect • Localization of Commercial SCR catalyst has been made progress. How to reduce the cost of catalyst, establish of catalyst regeneration center. • Novel Cr-MnOx, Fe-MnOx, Mn-Zr catalysts with well low-temperature SCR activity have been developed; If we can not solve the problem of high activity at low temperature(＜120℃)，should we change our thinking. • Series of VMn, VCu, and modified catalysts are studying systematically. How to improve the activity of the catalyst under high concentration of SO2 is a huge challenge.

  30. Acknowlegment Ministry of Environmental Protection, China Ministry of Science Technology, China National Natural Science Foundation of China Natural Science Foundation of Guangdong, China Department of science and technology of Guangdong Province Department of science and information technology of Guangzhou South China University of Technology Thank you for your attention！

More Related