Session: 08-01: Poster Session

Paper Number: 149561

149561 - Understanding Gasoline Particulate Filters and Particulate Mass Emission Requirements for Tier 4 

Abstract: 

With the new Tier 4 regulation introduced by the EPA, particulate mass (PM) emission requirements are tighter than ever before. Tier 3 PM requirements are 3.0 mg/mi for FTP75 and 6.0 mg/mi for US06, while LEV IV requirements are 1.0 mg/mi and 3.0 mg/mi respectively. Tier 4 will require Light Duty vehicles to meet 0.5 mg/mi separately on FTP75 and US06 certification cycles. Additionally, the EPA is introducing a new test cycle for PM certification, FTP at -7 ^oC. Cold ambient conditions of this new test cycle will further increase the engine PM emissions, requiring high filtration efficiency GPFs.

Although particulate emissions in cold temperatures have been evaluated before, it is unknown how much the new -7 ^oC test will affect engine out PM and whether current GPF technologies will be able to meet this new requirement. GPFs have been widely used in Europe and other regions in the past, but ultra-low particulate requirements are new for the U.S. Additionally other regions regulate particulate number (PN) for particulate emissions reduction, while the U.S. regulates PM. The main difference between PN and PM is the measurement method, with PN counting the number of particles while PM measures the weight of particles collected on a filter paper. Estimating GPF PM filtration performance based on PN data is possible, but difficult due to limited experience, especially for -7 ^oC. Finally, the variation across each test cycle needs to be understood to determine which test cycle will be the most challenging to meet Tier 4.

To understand the impact of these new conditions and to better understand PM and PN differences, NGK conducted PM testing with several different GPF materials across several vehicles under FTP75, US06, and FTP at -7 ^oC to determine which GPF material would be the best candidate for Tier 4.

Presenting Author: Alejandro Newberry NGK Automotive Ceramics USA, Inc

Presenting Author Biography: Alejandro Newberry is a product engineer who has been working at NGK for 2 years supporting GPF development. Before that he attended the University of Michigan where he received a bachelor's degree in chemical engineering.

Authors:

Alejandro Newberry NGK Automotive Ceramics USA, Inc
Shogo Obata NGK Automotive Ceramics USA, Inc
Anoop Reghunathan-Nair NGK Automotive Ceramics USA, Inc
Hiroaki Ishikawa NGK Automotive Ceramics USA, Inc
Kyohei Kato NGK Automotive Ceramics USA, Inc.
Kiwamu Sugiura NGK Insulators, Ltd.