FEV, Inc. to Show Full-Sized Pickup Truck with Solid SCR System for NOx Reduction
15 April 2009
FEV, Inc. will show its Solid Selective Catalyst Reduction (SSCR) System—based on the use of solid ammonium carbamate (NH4NH2CO2) as the reductant—installed in a Dodge Ram pickup truck at the 2009 SAE World Congress, 20-23 April in Detroit. The Solid SCR system is installed on a Dodge Ram 2500 demonstrator truck that has been used as a technology carrier during the development process.
SCR technology uses ammonia, usually provided in the form of a urea solution, for the reduction of NOx. FEV designed the Solid SCR System as a viable alternative to a liquid urea injection system. With a volume reduction of approximately 70%, the SSCR system still offers equivalent or better performance than liquid urea systems.
(Ammonium carbamate is used in the commercial production of urea. Ammonia and carbon dioxide are reacted together under a pressure of 100-200 atm to form ammonium carbonate. This is followed by the endothermic thermal decomposition of ammonium carbamate, in a concentrated solution, to give a 50-60% conversion to urea.)
SSCR is scalable and can be sized to accommodate both light and heavy-duty applications, as well as off-highway and stationary applications.
A number of companies have investigated ammonium carbamate-based SCR systems; sublimation of the carbamate is achieved by a local heater (spray or electrically warmed oil circulation). Barriers to adoption have been the energy to reach the sublimation point and the system response time, according to Pascal Granger and Vasile I. Pârvulescu in Past and present in DeNOx catalysis. Other issues can include the filling of small, pressurized containers, and the safety aspect, according to a review of mobile SCR technology presented by Dr. Eberhard Jacob of Emitec at the 2006 Aachener Kolloquium.
FEV says its SSCR system requires less energy for sublimation of the ammonium carbamate solid, which occurs at 60 °C. Sublimation is also reversible as the cooling gas reforms back to ammonia carbamate.
The potential use of a solid urea cartridge-based SCR system would reduce or eliminate the issues associated with development of a large-scale infrastructure for a liquid urea refilling. Degradation concerns are also reduced due to use of a stable solid ammonia carbamate. The solid cartridge will last three times longer than a similarly sized liquid urea system and the SSCR system eliminates the need for costly heated tanks and supply lines.
Resources
M. Krüger, P. Nisius, V. Scholz, A. Wiartalla (2003) A compact Solid-SCR System for NOx-Reduction in Passenger Cars and Light Duty Trucks. MTZ Worldwide
Past and present in DeNOx catalysis, Pascal Granger, Vasile I. Pârvulescu. Elsevier, 2007 ISBN 0444530584, 9780444530585
Eberhard Jacob (2006) Perspectives on Mobile SCR Technology
Handbook of Chemical Technology and Pollution Control, M B Hocking. Second edition, Academic Press, 2005 ISBN 0120887967, 9780120887965
Incremental progress, but progress none the less.
Posted by: ExDemo | 15 April 2009 at 08:37 AM