Browse Publications Technical Papers 2005-01-3878
2005-10-24

Experimental Evaluation of Reformate-Assisted Diesel NOx Trap Desulfation 2005-01-3878

NOx adsorber catalysts are leading candidates for improving NOx aftertreatment in diesel exhaust. The major challenge in the use of adsorbers that capture NOx in the form of nitrates is their susceptibility to sulfur poisoning. Sulfur, which is present in diesel fuel, adsorbs and accumulates as sulfate (SO4-2) at the same adsorption sites as NOx, and, since it is more stable than nitrates, inhibits the ability of the catalyst to adsorb NOx. It is found that high temperature (> about 650 °C) in the presence of a reducing gas is required to release sulfur rapidly from the catalyst. Since the peak temperatures of diesel engine exhaust are below 400 °C, additional heat is required to remove the sulfur. This work describes a reformate-assisted “sulfur purge” method, which employs heat generated inside the NOx trap catalyst by exothermic chemical reactions between the oxygen in diesel exhaust and injected reformate (H2 + CO). Our results with a laboratory gas bench system show that catalyst desulfation is successful following a desulfation schedule with an inlet gas temperature of about 300 °C. In addition, we have examined impact of temperature, duration of exposure, and reformate-based gas compositions employed for rich-gas desulfation on NOx adsorber efficiency.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 18% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:
TECHNICAL PAPER

Lean NOx Reduction in Two Stages: Non-thermal Plasma Followed by Heterogeneous Catalysis

2000-01-2896

View Details

TECHNICAL PAPER

A Study on Diesel Emission Reduction using a High-frequency Dielectric Barrier Discharge Plasma

2003-01-1879

View Details

TECHNICAL PAPER

Non Thermal Plasma Aftertreatment of Particulates - Theoretical Limits and Impact on Reactor Design

2000-01-1926

View Details

X