lnu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Deactivation of SCR Catalysts by Exposure to Aerosol Particles of Potassium and Zinc Salts
Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design. Bioenergiteknik.ORCID iD: 0000-0002-5835-865X
Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design. Bioenergiteknik.
Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design. Bioenergiteknik.
2007 (English)In: Aerosol Science and Technology, ISSN 0278-6826, E-ISSN 1521-7388, Vol. 41, no 4, p. 369-379Article in journal (Refereed) Published
Abstract [en]

Generated aerosol particle deposition has been applied in laboratory scale to induce deactivation of commercial Selective Catalytic Reduction (SCR) catalysts Of V2O5-WO3/TiO2 monolithic type. The monolithic catalyst has been exposed to the generated submicrometer particle of inorganic salts, KCl, K2SO4, and ZnCl2 at 200 degrees C in a tubular reactor. The generated particles have been deposited on the catalytic surfaces by utilization of an electrostatic field. Physical characterization of the generated aerosol particles were conducted by Scanning Mobility Particle Sizer (SMPS) and Electric Low Pressure Impactor (ELPI) with and without catalyst in order to investigate the magnitude of the particle deposition. Particle charge distribution was also evaluated with a Tandem Differential Mobility Analyser (TDMA) set up.

SCR is the most common method to commercially reduce NOx emissions from combustion processes. Catalyst lifetime is important for process economics and extending catalyst life can allow future strengthened emission legislation and diminished NOx emissions.

Verification of particle deposition has been conducted through comparison with catalyst samples exposed to commercial biomass combustion condition.

The reactivity of both fresh and exposed catalyst samples as well as commercially used samples was examined in SCR reaction and the methods of deposition as well as the influence of the different salts on catalytic performance have been explored.

Catalyst samples have been evaluated with Scanning Electron Microscopy (SEM) with respect to surface morphology of the catalyst material. The laboratory deactivated catalyst samples showed resemblance with the commercially exposed catalyst sample with respect to salts concentration and deposition of the salts particles. The obtained influence on catalyst activity was comparable with commercially obtained catalyst activity reductions at comparable potassium concentration levels.

Place, publisher, year, edition, pages
2007. Vol. 41, no 4, p. 369-379
National Category
Energy Engineering
Research subject
Technology (byts ev till Engineering), Bioenergy Technology
Identifiers
URN: urn:nbn:se:vxu:diva-4261DOI: 10.1080/02786820701203207OAI: oai:DiVA.org:vxu-4261DiVA, id: diva2:204219
Available from: 2007-12-14 Created: 2007-12-14 Last updated: 2017-12-13Bibliographically approved
In thesis
1. Study of Catalyst Deactivation in Three Different Industrial Processes
Open this publication in new window or tab >>Study of Catalyst Deactivation in Three Different Industrial Processes
2007 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Deactivation of catalysts were investigated focusing on three industrial processes: 1) Selective Catalytic Reduction (SCR) for abatement of NOx from biomass combustion using V2O5-WO3 /TiO2 catalysts; 2) Catalytic oxidation of volatile organic compounds (VOC) from printing industries using a Pt/γ-Al2O3 catalyst; and 3) Ni and Pt/Rh catalysts used in steam reforming reaction of bio-syngas obtained from biomass gasification.

The aim has been to simulate industrial conditions in laboratory experiments in order to comprehend influence of compounds affecting catalysts performance. Typical catalyst lifetimes in industrial processes are several years, which are a challenge when accelerating deactivation in laboratory scale experiments where possible exposure times are few hours or days. Catalysts can be introduced to deactivating compounds through different routes. The first method examined was gaseous exposure, which was applied to deactivate VOC oxidation catalyst through exposure of gaseous hexamethyldisiloxane. The second method involved wet impregnation and was used for impregnation of SCR catalyst with salt solutions. The third method was based on exposure and deposition of size selected particles of deactivating substances on the catalyst. The latter device was developed during this work. It was applied to monolithic SCR catalysts as well as to pellet catalysts intended for steam reforming of biomass gasification syngas. Deactivated SCR catalyst samples by size selected exposure method were verified and compared with SCR catalysts used in a commercial biomass boiler for 6 500 h.

Evaluations of fresh and deactivated samples were investigated using BET surface area; chemisorption and temperature programmed desorption (TPD); surface morphology using Scanning Electron Microscopy (SEM) and poison penetration profile through SEM with an Electron Micro Probe Analyser (EMPA) also equipped with a energy dispersive spectrometer (EDS); chemical analysis of accumulation of exposed compounds by Inductively Coupled Plasma - Atomic Emission Spectroscopy (ICP-AES); and influence on catalyst performance. The size selected generated particles of deactivating substances were characterized with respect to mean diameter and number size distribution through Scanning Mobility Particle Sizer (SMPS) and mass size distribution applying an Electric Low Pressure Impactor (ELPI). Results from catalyst characterization methods were useful tools in evaluation of catalyst deactivation routes.

Understanding deactivation processes and impact on catalyst performance is vital for further optimization of catalysts with respect to performance and lifetime. Further research in this field can provide more resistant catalysts for application in industry leading to higher commercial benefits and further application of environmental catalysts in thermo-chemical conversion of biomass.

Place, publisher, year, edition, pages
Växjö: Växjö University Press, 2007
Series
Acta Wexionensia, ISSN 1404-4307 ; 106/2007
Keywords
deactivation, catalyst, SCR, VOC, steam reforming, aerosol particle, potassium, zinc, ash salts, biomass, organosilicon
National Category
Chemical Engineering
Research subject
Natural Science, Chemistry
Identifiers
urn:nbn:se:vxu:diva-1058 (URN)978-91-7636-533-5 (ISBN)
Public defence
2007-02-02, M1083, M, Växjö univsersitet, Växjö, 13:00
Opponent
Supervisors
Available from: 2007-02-01 Created: 2007-02-01 Last updated: 2017-02-24Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full text

Authority records BETA

Larsson, Ann-CharlotteEinvall, JessicaSanati, Mehri

Search in DiVA

By author/editor
Larsson, Ann-CharlotteEinvall, JessicaSanati, Mehri
By organisation
School of Technology and Design
In the same journal
Aerosol Science and Technology
Energy Engineering

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 83 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf