Full Content is available to subscribers

Subscribe/Learn More  >

Modeling Competitive Adsorption in Urea-SCR Catalysts for Effective Low Temperature NOx Control

[+] Author Affiliations
Maruthi Devarakonda, Russell Tonkyn, Diana Tran, Jong H. Lee, Darrell Herling

Pacific Northwest National Laboratory, Richland, WA

Paper No. IMECE2010-39977, pp. 589-595; 7 pages
  • ASME 2010 International Mechanical Engineering Congress and Exposition
  • Volume 11: New Developments in Simulation Methods and Software for Engineering Applications; Safety Engineering, Risk Analysis and Reliability Methods; Transportation Systems
  • Vancouver, British Columbia, Canada, November 12–18, 2010
  • Conference Sponsors: ASME
  • ISBN: 978-0-7918-4448-9
  • Copyright © 2010 by ASME


Although the SCR technology exhibits higher NOx reduction efficiency over a wider range of temperatures among the lean NOx reduction technologies, further improvement in low-temperature performance is required to meet the future emission standards and to lower the system cost. In order to improve the catalyst technologies and optimize the system performance, it is critical to understand the reaction mechanisms and catalyst behaviors with respect to operating conditions. For example, it is well known that the ammonia coverage on catalyst surface is critical for NOx reduction efficiency. However, the level of ammonia storage is influenced by competitive adsorption by other species, such as H2 O and NO2 . Moreover, hydrocarbon species that slip through the upstream DOC during the cold-start period can also inhibit the SCR performance, especially at low temperatures. Therefore, a one-dimensional kinetic model that can account for the effects of such competitive adsorption has been developed based on steady state surface isotherm tests on a commercial Fe-zeolite catalyst. The model is developed as a C language S-function and implemented in Matlab/Simulink environment. Rate kinetics of adsorption and desorption of each of the adsorbents are determined from individual adsorption tests and validated for a set of test conditions that had all the adsorbents in the feed gas. Using the competitive adsorption model, a kinetic model for standard-SCR reaction involving NH3 and H2 O is developed and validated.

Copyright © 2010 by ASME



Interactive Graphics


Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In