The Open UniversitySkip to content

The use of the Continuously Regenerating Trap (CRTTM) and SCRTTM Systems to meet future emissions legislation

Allansson, R.; Blakeman, P. G.; Chandler, G. R.; Maloney, C. A.; Thoss, J. E.; Walker, A. P. and Warren, J. P. (2000). The use of the Continuously Regenerating Trap (CRTTM) and SCRTTM Systems to meet future emissions legislation. In: Fortschritt-Berichte VDI, VDI, Technical University of Vienna, Vienna, 12(420) pp. 343–355.

Full text available as:
PDF (Accepted Manuscript) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Download (14kB) | Preview
Google Scholar: Look up in Google Scholar


The progressive tightening of particulate matter (PM) legislation presents challenges to the engine development and aftertreatment communities. The Continuously Regenerating Trap (CRTTM) has been developed to enable diesel engines to meet the proposed future legislation. This passive filter system combines an oxidation catalyst with a Diesel Particulate Filter (DPF); the filter traps the PM and the oxidation catalyst generates NO2 which combusts the trapped PM at substantially lower temperatures than is possible using oxygen. This paper outlines the operating principle of the CRTTM, and describes the performance of the system. It has been shown that the very high PM conversions obtained with the CRTTM can enable even Euro 1 engines to meet the PM limits proposed for introduction in Europe in 2005. In addition, the system removes PM across the whole particle size range, including ultrafine particulates. These results will be discussed, as will in-field durability studies which have shown that the system is still capable of converting 90% of PM after very high mileage operation (up to 600,000 km). In addition to requiring very high PM conversion, the proposed future legislation requires substantial reductions in NOx emissions form heavy duty diesel vehicles. To meet these challenges the SCRTTM has been developed. This combines the CRTTM with SCR (Selective Catalytic Reduction) technology, and enables very high simultaneous conversions of CO, HC, PM and NOx to be achieved. The SCRTTM system is described, and its operating characteristics are discussed. It has been shown that the SCRTTM can potentially meet the legislative limits proposed for introduction in Europe in 2008.

Item Type: Conference or Workshop Item
Copyright Holders: 2000 Johnson Matthey and the Authors.
ISBN: 3-18-342012-0, 978-3-18-342012-4
ISSN: 0178-9449
Keywords: diesel; aftertreatment; catalyst; CRT; SCR; SCRT; particulate matter
Academic Unit/School: Faculty of Science, Technology, Engineering and Mathematics (STEM) > Engineering and Innovation
Faculty of Science, Technology, Engineering and Mathematics (STEM)
Research Group: Design and Innovation
Related URLs:
Item ID: 47903
Depositing User: James Warren
Date Deposited: 28 Nov 2016 11:27
Last Modified: 07 Dec 2018 19:28
Share this page:

Download history for this item

These details should be considered as only a guide to the number of downloads performed manually. Algorithmic methods have been applied in an attempt to remove automated downloads from the displayed statistics but no guarantee can be made as to the accuracy of the figures.

Actions (login may be required)

Policies | Disclaimer

© The Open University   contact the OU