Patent ID: 6978601
Filing Date: 2005-12-27
Classification: B01D,F01N,F02D,Y02T

Abstract:
1. A diesel (compression ignition) engine having combustion management means and an exhaust gas aftertreatment system which system comprising a platinum group metal (PGM) catalyst liable to be poisoned by fuel sulfur to cause significant degradation of catalyst performance, which engine is fuelled, at least intermittently, by a fuel containing such levels of sulfur as to cause poisoning of the catalyst, wherein the combustion management means is effective to modulate the air/fuel ratio (λ) in pulses to 0.95 or richer to provide a series of peak enrichments of from 250 milliseconds to 5 seconds in duration for an aggregate time of from 10 seconds to 10 minutes, whereby the catalyst is regenerated, and wherein the exhaust gas aftertreatment system does not include a NO x trap.