Aftertreatment Technologies for Off-Highway Heavy-Duty Diesel Engines

Technical Report · Tue Jul 15 04:00:00 EDT 2008

DOI:https://doi.org/10.2172/940361· OSTI ID:940361

Kass, M D

The objective of this program was to explore a combination of advanced injection control and urea-selective catalytic reduction (SCR) to reduce the emissions of oxides of nitrogen (NOx) and particulate matter (PM) from a Tier 2 off-highway diesel engine to Tier 3 emission targets while maintaining fuel efficiency. The engine used in this investigation was a 2004 4.5L John Deere PowerTechTM; this engine was not equipped with exhaust gas recirculation (EGR). Under the original CRADA, the principal objective was to assess whether Tier 3 PM emission targets could be met solely by increasing the rail pressure. Although high rail pressure will lower the total PM emissions, it has a contrary effect to raise NOx emissions. To address this effect, a urea-SCR system was used to determine whether the enhanced NOx levels, associated with high rail pressure, could be reduced to Tier 3 levels. A key attraction for this approach is that it eliminates the need for a Diesel particulate filter (DPF) to remove PM emissions. The original CRADA effort was also performed using No.2 Diesel fuel having a maximum sulfur level of 500 ppm. After a few years, the CRADA scope was expanded to include exploration of advanced injection strategies to improve catalyst regeneration and to explore the influence of urea-SCR on PM formation. During this period the emission targets also shifted to meeting more stringent Tier 4 emissions for NOx and PM, and the fuel type was changed to ultra-low sulfur Diesel (ULSD) having a maximum sulfur concentration of 15 ppm. New discoveries were made regarding PM formation at high rail pressures and the influences of oxidation catalysts and urea-SCR catalysts. These results are expected to provide a pathway for lower PM and NOx emissions for both off- and on-highway applications. Industrial in-kind support was available throughout the project period. Review of the research results were carried out on a regular basis (annual reports and meetings) followed by suggestions for improvement in ongoing work and direction for future work. A significant portion of the industrial support was in the form of experimentation, data analysis, data exchange, and technical consultation.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN
• Sponsoring Organization: USDOE Assistant Secretary for Energy Efficiency and Renewable Energy (EE)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 940361
• Report Number(s): ORNL02-0666
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
CATALYSTS
DATA ANALYSIS
DIESEL ENGINES
DIESEL FUELS
EFFICIENCY
ENGINES
EXPLORATION
NITROGEN
OXIDATION
OXIDES
PARTICULATES
REGENERATION
SULFUR
TARGETS