Browse Publications Technical Papers 2014-01-1537
2014-04-01

Development and Demonstration of LNT+SCR System for Passenger Car Diesel Applications 2014-01-1537

The regulations for mobile applications will become stricter in Euro 6 and further emission levels and require the use of active aftertreatment methods for NOX and particulate matter. SCR and LNT have been both used commercially for mobile NOX removal. An alternative system is based on the combination of these two technologies. Developments of catalysts and whole systems as well as final vehicle demonstrations are discussed in this study.
The small and full-size catalyst development experiments resulted in PtRh/LNT with optimized noble metal loadings and Cu-SCR catalyst having a high durability and ammonia adsorption capacity. For this study, an aftertreatment system consisting of LNT plus exhaust bypass, passive SCR and engine independent reductant supply by on-board exhaust fuel reforming was developed and investigated. The concept definition considers NOX conversion, CO2 drawback and system complexity. The passive SCR significantly contributes to the total NOX conversion over a broad temperature range. In contrary to conventional LNT applications, the LNT NOX slip does not directly reduce the system NOX conversion but can be converted over the passive SCR. Thereby, the NOX adsorption duration might be prolonged, resulting in lower LNT regeneration frequency and less fuel consumption, resp. CO2 emissions. Additionally, the engine independent LNT enrichment is beneficial regarding fuel consumption in comparison to conventional engine internal enrichment.
The system has been tested in a vehicle in combination with a highly efficient Diesel engine. Results regarding CO2 and NOX as well as their dependency on temperatures are shown here.

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.
We also recommend:
TECHNICAL PAPER

Study on Optimization for LNT+SCR System of Diesel Vehicle to Comply with the LEV3 Regulations

2014-01-1529

View Details

TECHNICAL PAPER

Detection of Injected Urea Quantity and Correction for SCR Urea Dosing Control

2015-01-1038

View Details

TECHNICAL PAPER

Effects of Diesel Exhaust Fluid (DEF) Injection Configurations on Deposit Formation in the SCR System of a Diesel Engine

2016-28-0109

View Details

X