AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
Determination of Suspended Exhaust PM Mass for Light Duty Vehicles Using IPSD Method
HEEJUNG S. JUNG, Yang Li, Jian Xue, Kent Johnson, Thomas D. Durbin, Mark Villela, Liem Pham, Seyedehsan Hosseini, Zhongqing Zheng, Daniel Short, Georgios Karavalakis, Akua Asa-Awuku, Xiaoliang Wang, David Quiros, Shaohua Hu, Tao Huai, Alberto Ayala, University of California Riverside
Abstract Number: 21 Working Group: Combustion
Abstract In line with stricter PM emission standards for heavy-duty vehicles, the United States Environmental Protection Agency and the California Air Resources Board will implement stricter PM standards on light-duty vehicles. California’s new PM emission standard will be reduced to 1 mg/mile, which poses a challenge to the current gravimetric measurement method. The European Union (EU) will implement a particle number (PN) emission standard and has proposed to use the Particle Measurement Programme’s PN measurement protocol as a complementary measurement to the PM mass standard. The current EU PN standard excludes sub 23 nm particles which are mostly volatile but may be responsible for significant adverse health effects. There is limited information regarding associations between human health effects and PN emissions. Also PN and PM do not necessarily correlate with each other over a variety of test conditions, which poses questions to regulators regarding whether particle number is an appropriate metric to replace current particle mass-based measurement protocols.
This study presents determination of suspended exhaust PM mass as opposed to filter captured PM mass as a possible alternative metric to complement current gravimetric method. One example is the integrated particle size distribution (IPSD) method which combines particle size distribution with size dependent particle effective density. The method allows for simultaneous determination of particle mass, particle surface area, and particle number. As IPSD can simultaneously obtain PM as well as PN, it has the potential to explain discrepancies between current gravimetric method and particle number method. The paper presents comparison of suspended PM mass determined by the IPSD method with gravimetric PM mass. Final goal of this project is to assess repeatability and accuracy of alternative methods to determine suspended PM mass to examine appropriateness as future regulatory measurement methods.