Evolution of Lean-NOx Traps on PFI and DISI Lean Burn Vehicles Dunton Engineering Centre, Ford Motor Company Limited

Format:

Conference/Event

Author/Creator:

Gregory, D., author.

Conference Name:

International Fuels and Lubricants Meeting and Exposition (1999-10-25 : Toronto, Canada)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 1999

Summary:

This paper charts the development of three three-way catalyst (TWC) and four lean-NOx trap (LNT) formulations in four vehicle systems over a four-year period. All LNTs were installed in an underbody location behind a close-coupled TWC on vehicles equipped with either port fuel injection (PFI) or direct injection spark ignition (DISI) engines. In addition to the standard regulatory European drive cycles, a series of steady-state tests were conducted to determine changes in LNT NOx efficiency with increasing NOx storage, and changes in the levels of individual nitrogen-containing exhaust components. Each vehicle system was subjected to a durability cycle up to an equivalent of 80,000 km. The early LNT formulations on systems 1' and 2' suffered from inadequate thermal durability with system efficiencies for NOx deteriorating to 55% after vehicle aging under lean operating drive cycle conditions (from 80% when fresh). As a result, improvements were made to the LNT formulations on systems 3' and 4'. Only minor deterioration in lean NOx performance was observed after vehicle aging on these systems ( 90% NOx efficiency after aging). These improvements have been such that ECE Stage III and IV NOx emission targets have been achieved after aging with PFI and DISI lean-burn gasoline technology, respectively

Notes:

Vendor supplied data

Publisher Number:

1999-01-3498

Access Restriction:

Restricted for use by site license