Particle Emissions during Heavy-Duty Truck Parked Active Diesel Particulate Filter Regeneration

This page last reviewed April 6, 2015


Diesel particulate filters (DPFs) collect Particulate Matter (PM) and this PM must be periodically removed from the DPF or the vehicle performance will be degraded. The process of removing the PM is known as regeneration, during which there is an increase in emissions. Depending on the duty cycle of the Heavy Duty Diesel, HDD, vehicle the regeneration of the DPF can take many different forms and frequency of occurrence. The present study is concerned with active regeneration processes, which typically generate a very large number of ultrafine volatile and semi-volatile particles from both highway vehicles and parked vehicles. The need for an active regeneration occurs for vehicles that have a low exhaust temperature duty cycle, and these vehicles may or may not be able to change their duty cycle to a more aggressive and high exhaust temperature highway cycle. It is important that more information be obtained concerning “Parked” regeneration, particularly concerning the nature and importance of the very large number of ultrafine volatile and semi-volatile particles that are released in the immediate vicinity of the diesel truck. A clearer understanding during regeneration of emitted PM composition, toxicity, and exposure potential is needed if DPFs are indeed found to increase average vehicle total particle number emissions when regeneration is included (Note: Total particles include solid, volatile, and semi-volatile particles). By knowing more information concerning PM physical properties and the time and space distribution of these particles, researchers can begin to understand and evaluate the possible health effects.



  • Harry Dwyer (September, 2013). Measurement of Emissions from both Active and Parked Regenerations of a Diesel Particulate Filter from Heavy Duty Trucks. ARB Research Final Report (PDF - 13,445KB)

Publications for Peer-reviewed Journals

  • Seungju Yoon et al., 2015. Characteristics of Particle Number and Mass Emissions during Heavy-Duty Diesel Truck Parked Active DPF Regeneration in an Ambient Air Dilution Tunnel. sumbitted to Atmospheric Environment
  • Harry Dwyer et al., 2014. Ambient Emission Measurements from Parked Regenerations of 2007 and 2010 Diesel Particulate Filters. SAE Technical Paper 2014-01-2353; SAE International: Warrendale, PA.
  • David Quiros et al., 2013. Measuring particulate matter emissions during parked active diesel particulate filter regeneration of heavy-duty diesel trucks. Journal of Aerosol Science. 2014, 73, 48-62.

Conference Presentations

  • 24th CRC Real-World Emissions Workshop, March 30–April 2, 2014, San Diego, CA
  • Harry Dwyer et al., (2014). Design and performance of an Ambient Dilution Wind Tunnel Applied to Heavy Duty Diesel Truck Parked Active DPF Regeneration. in preparation
  • Air Quality Measurement Methods and Technology Conference, November 19-21, 2013, Sacramento, CA
  • David Quiros et al., (2013). Evaluation of PM Mass Emissions Associated with Active Diesel Particulate Filter Regeneration from Parked Heavy-Duty Trucks Using an Ambient-Dilution Wind Tunnel. Presentation (PDF - 998KB)