Microscopy investigations of ash and particulate matter accumulation in diesel particulate filter surface pores

There has been increased focus on the environmental impact of automobile emissions in recent years. These environmental concerns have resulted in the creation of more stringent particulate matter emissions regulations in the United States and European Union. These limits have forced diesel engine manufacturers to reduce particulate matter (PM) emissions by an order of magnitude beginning in 2007. Diesel particulate filters (DPF) provide the most effective means of reducing PM emissions from diesel exhaust. DPFs can reduce over 99% of PM in the exhaust. DPF effectiveness is limited by the accumulation of ash. Ash is comprised of incombustible material from engine lubricants. Engine oil additives based on P, Zn, S, Ca, and Mg are responsible for the majority of ash. Ash accumulation in DPFs reduces their useful life by plugging the filter's inlet channels. Ash deposition leads to increased pressure drop across the DPF, which reduces the engine's performance and negatively impacts fuel economy. The process of ash accumulation in DPF channels is not well understood. This research is focused on exploring the ash interactions with DPF walls, pores, and the catalyst washcoat. Based on scanning electron microscopy analysis of ash loaded DPFs from the field and from filters loaded with ash in the laboratory, a mechanism for ash accumulation is presented.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2010

Author dc:creator

• Beauboeuf, Daniel P

Advisor dc:contributor.advisor

• Alexander Sappok and Victor Wong.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/59894

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/59894