17 September 2008
Johnson Matthey announced that a demonstration of its SCRT® diesel retrofit technology has been launched with a fleet of grocery trucks owned by the Ralph’s supermarket chain in southern California. Johnson Matthey and its partner, Cummins Emissions Solutions, retrofitted 16 older (model year 1998-2004) Class 8 trucks with the SCRT system.
Johnson Matthey will collect data on the vehicle’s emissions performance by measuring back pressure, exhaust temperature and NOx concentrations.
The SCRT emission control system combines Johnson Matthey’s two-stage CRT particulate filter with a selective catalytic reduction (SCR) catalyst. The SCR catalyst reduces NOx by some 60 to 80% through reactions with urea, which is injected upstream of the catalyst. The particulate filter provides an over 85% PM emission reduction, as well as reductions in CO & HC emissions.
In a previous test in the Sacramento area, Johnson Matthey found that the SCRT system reduced NOx by an average of 84% compared to pre-retrofit levels. Those trucks had 2005 Cummins, 400 hp ISM engines with an EGR system.
The verification of the SCRT technology by the California Air Resources Board and the US Environmental Protection Agency is expected by the end of 2008 or early 2009, said Johnson Matthey. The system was recently granted the “emerging technology” status by the EPA, which allows commercial sales before the verification testing is completed.
Johnson Matthey has nearly 50 SCRT demonstration units running in California and Texas on both EGR and non-EGR engines.
Source: Johnson Matthey