Selective Catalytic Reduction (SCR) Deactivation Kinetics Study for Aging, Control and OBD Applications, 03-R8048
Printer Friendly VersionPrincipal Investigators
Gordon J.J. Bartley
Theodore M. Kostek
Reggie Zhan
Inclusive Dates: 04/01/09 – 04/01/10
Background - Urea Selective Catalytic Reduction (SCR) is one of the prevailing technologies that will be used to reduce NOx emissions from diesel engines down below 2010 and Euro-6 heavy-duty and Tier 2 light-duty emission limits. SwRI continues to perform research, development and testing work to support our clients and advance the understanding of this important technology. The current project seeks to provide data to feed into three key areas: refining model-based controls to include progressive deactivation, determining deactivation energies for use in accelerated aging cycle protocols, and evaluating proposed on-board diagnostic (OBD) methodologies.
Approach - SwRI is using its Universal Synthetic Gas Reactor® (USGR®) to perform all of the aging and testing work. The USGR has the ability to provide catalyst core samples with accurate mixtures of simulated exhaust gases under controlled conditions of concentration, flow rate and temperature. It is relatively cost-effective, less time-consuming to generate data, and more precise than engine-based approaches. Catalyst cores are aged at various temperatures for various times using a suitable aging gas mixture. Three test types are then performed at each aging point to obtain data relevant to each of the three key areas. There are three SCR catalyst formulations currently of interest. These are V/W/TiO2, Cu-zeolite and Fe-zeolite. The tests are being performed on all three formulations.
Accomplishments - SwRI has obtained samples of the three catalyst formulations from the major catalyst manufacturers, obtained test gases and set up the USGR to perform the aging and testing work. Initial reaction-order tests were performed to identify the reaction orders of the reactant gases for both the standard and fast SCR reactions. Work has now begun on the aging and testing portion of the project. There is insufficient data at this time to present any results or conclusions.
