Three-Way Catalyst Design for Urealess Passive Ammonia SCR: Lean-Burn SIDI Aftertreatment System General Motors Company

Format:

Conference/Event

Author/Creator:

Kim, Kim, author.

Contributor:

Li, Wei

Narayanaswamy, Kushal

Perry, Kevin

Viola, Michael

Conference Name:

SAE 2011 World Congress & Exhibition (2011-04-12 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2011

Summary:

Lean-burn SIDI engine technology offers improved fuel economy;however, the reduction of NOx during lean-operationcontinues to be a major technical hurdle in the implementation ofenergy efficient technology. There are several aftertreatmenttechnologies, including the lean NOx trap and activeurea SCR, which have been widely considered, but they all sufferfrom high material cost and require customer intervention to fillthe urea solution. Recently reported passive NH₃-SCR system - asimple, low-cost, and urea-free system - has the potential toenable the implementation of lean-burn gasoline engines.Key components in the passive NH₃-SCR aftertreatment systeminclude a close-coupled TWC and underfloor SCR technology. NH₃ isformed on the TWC with short pulses of rich engine operation andthe NH₃ is then stored on the underfloor SCR catalysts. Onsubsequent lean operations during the NEDC transient cycles, theNOx that breaks through the TWC converter is reduced bystored NH₃ on the SCR catalysts. The design of the TWC is crucialfor NH₃ generation and critical for HC/CO emission reduction due tothe low exhaust temperatures. In summary, the passive NH₃ SCR hasbeen demonstrated as an efficient and low cost lean NOxaftertreatment technology for lean-burn SIDI. These and otherresults including steady-state results will be presented

Notes:

Vendor supplied data

Publisher Number:

2011-01-0306

Access Restriction:

Restricted for use by site license