NH3 Generation Characteristics of a LNT Catalyst Downstream

Title & Authors
NH3 Generation Characteristics of a LNT Catalyst Downstream
Seo, Choong-Kil;

Abstract
As diesel engines have high power and good fuel economy on top of less $\small{CO_2}$ emissions, their market shares are increasing not only in commercial vehicles but also in passenger cars. LNT, urea-SCR and combination of them have been developed for after-treatment of the exhaust gas to reduce NOx on diesel vehicles. The aim of this study is to investigate the $\small{NH_3}$ generation characteristics of LNT catalyst downstream. It was found from the experiments of the LNT catalyst that $\small{H_2}$ was useful as a reductant in SCR catalyst because it can enhance the de-NOx performance and improve $\small{NH_3}$ selectivity. The $\small{NH_3}$ generation of the LNT, when hydrothermally aged at $\small{900^{\circ}C}$ for 18 hr, increased to about 90ppm at $\small{300^{\circ}C}$ due to Pt sintering and Ba agglomeration. LNT catalyst was most sulfur poisoning at $\small{500^{\circ}C}$. The $\small{NH_3}$ slip increased due to the reduction of residence time according to SV increase.
Keywords
Diesel engine;Catalyst;Lean NOx Trap;Selective Catalytic Reduction;$\small{NH_3}$;
Language
Korean
Cited by
1.
The De-CH4Characteristics of NGOC for CH4Reduction of a CNG Bus, Journal of the Korea Society For Power System Engineering, 2016, 20, 4, 69
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