Hydrogen Effect on the DeNOX Efficiency Enhancement of Fresh and Aged Ag/Al2O3 HC-SCR in a Diesel Engine Exhaust GMDAT

Format:

Conference/Event

Author/Creator:

Kim, Kim, author.

Contributor:

Chun, Kwang Min

Gu, Hyerim

Han, Hyun Sik

Song, Soonho

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:

HC-SCR is more convenient when compared to urea-SCR, since forHC-SCR, diesel fuel can be used as the reductant which is alreadyavailable onboard the vehicle. However, the DeNOXefficiency for HC-SCR is lower than that of urea-SCR in both lowand high temperature windows. In an attempt to improve theDeNOX efficiency of HC-SCR, the effect of hydrogen wereevaluated for the fresh and aged catalyst over 2 wt.% Ag/Al₂O₃using a Euro-4 diesel engine.In this engine bench test, diesel fuel as the reductant wasinjected directly into the exhaust gas stream and the hydrogen wassupplied from a hydrogen bomb. The engine was operated at 2,500 rpmand BMEP 4 bar. The engine-out NOX was around 180ppm-200 ppm. H₂/NOX and HC₁/NOX ratios were5, 10, 20, and 3, 6, 9, respectively. The HC-SCR inlet exhaust gastemperatures were around 215°C, 245°C, and 275°C. The catalystvolumes used in this test were 2.5L and 5L for both fresh and agedcatalysts.The DeNOX efficiency of the 5L fresh catalyst was inthe range of 0-25% without hydrogen, but it increased to 14-79%when the hydrogen was added to the feed stream. The finalefficiency was a function of the hydrocarbon and hydrogenconcentrations in the exhaust gas mixtures and the HC-SCR inlettemperatures. The NOX conversion efficiency of the 5Laged catalyst, which had been aged thermally at 750°C for 25 hrs inan electrical furnace, was in the range of 6-75% with hydrogen and2-22% without hydrogen. In case of the 2.5L catalyst, theDeNOX efficiency was in the range of 8-35% for the freshcatalyst and 3-9% for the aged catalyst with hydrogen. In theabsence of hydrogen, the NOX conversion rate was in therange of 3-8% and 3-5% for the fresh and aged catalyst,respectively

Notes:

Vendor supplied data

Publisher Number:

2011-01-1278

Access Restriction:

Restricted for use by site license