On Road Animal Inhalation Studies

On Road CRT Studies

On Road Source Apportionment Studies


On-Road CRT Studies

Kittelson, D. B., W. F. Watts, J. P. Johnson, C. Thorne, C. McCann, M. Payne, S. Goodier, C. Warrens, H. Preston U. Zink, D. Pickles, C. Goersmann, M. V. Twigg, A. P. Walker and R. Boddy. 2008.

Effect of Fuel and Lube Oil Sulfur on the Performance of a Diesel Exhaust Gas Continuously Regenerating Trap.

Environ. Science & Technol. 42:9276-9282. Link To Paper


     The continuously regenerating trap (CRT) is a diesel exhaust emission control that removes nearly all diesel particulate matter on a mass basis, but under some circumstances oxidation of sulfur leads to the formation of nanoparticles. The objective of the four year study was to determine CRT performance under controlled, real-world, on-road conditions, and to develop quantitative relationships between fuel and lubrication oil sulfur concentration and particle number exhaust emissions. It was shown that nanoparticle emissions are minimized by the use of ultralow sulfur fuels and specially formulated low sulfur lubrication oil. Nanoparticle emissions increased with higher exhaust temperatures. Fuel and lubrication oil sulfur increased the particle concentration by, on average, 36 × 106 and 0.14 × 106 part/cm3 for each 1 ppm increase in sulfur. On the other hand there was a decrease in nanoparticle emissions by the CRT as the system aged.

Kittelson, D. B., W. F. Watts, J. P. Johnson, C. Rowntree, M. Payne, S. Goodier, C. Warrens, H. Preston U. Zink, M. Ortiz, C. Görsmann, M. V. Twigg, A. P. Walker and R. Caldow. 2006.

On-Road Evaluation of Two Diesel Exhaust Aftertreatment Devices.

J. Aerosol Science, 37:1140 - 1151. Link to Paper


     Two Diesel particulate matter emission control devices; the continuously regenerating trap (CRTTM) and the catalyzed continuously regenerating trap (CCRTTM) were evaluated using a mobile emissions laboratory. The source of emissions was the lab's engine that was fueled with 15 ppm sulfur fuel, and specially formulated, low sulfur (1300 ppm) lubrication oil. The objective was to characterize performance using real-time aerosol instrumentation, real-world dilution, and on-road driving conditions.
     The devices when combined with low S fuel and lube oil effectively removed Diesel particulate matter. The CRT produced large quantities of nuclei mode particles, the quantity of which increased as a function of exhaust temperature. The CCRT reduced the exhaust particle number concentration to levels not detectable above background storage sites, thus eliminating precursors that form nuclei mode particles. Use of low S fuel and lubrication oil prolongs the storage process. Over time it is expected that this material would be released.

Kittelson, D. B., W. F. Watts, J. P. Johnson, C. J. Rowntree, S. P. Goodier, M. J. Payne, W. H. Preston, C. P. Warrens, M. Ortiz, U. Zink, C. Goersmann, M. V. Twigg, A. P. Walker. 2006.

Driving Down On-Highway Particulate Emissions.

SAE Technical Paper Series 2006-01-0916. Link to Paper


      It has been reported that particulate emissions from diesel vehicles could be associated with damaging human health, global warming and a reduction in air quality. These particles cover a very large size range, typically 3 to 10,000 nm. Filters in the vehicle exhaust systems can substantially reduce particulate emissions but until very recently it was not possible to directly characterize actual on-road emissions from a vehicle. This paper presents the first study of the effect of filter systems on the particulate emissions of a heavy-duty diesel vehicle during real-world driving. The presence of sulfur in the fuel and in the engine lubricant can lead to significant emissions of sulfate particles \ml 30 nm in size (nanoparticles). We have demonstrated that when using low-sulfur fuel in combination with a uniquely formulated low-sulfur lubricant and a suitable filter system that the particulate emissions of a heavy-duty vehicle were reduced to the levels already present in the ambient environment.

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Last modified: 29 January 2009