The Necessity of Optimizing the Interactions of Advanced Post-Treatment Components in Order to Obtain Compliance with SULEV-Legislation

Abstract

Fleet tests conducted on electrical vehicles around the world have very clearly shown that battery-powered cars may be regarded as zero-emission vehicles with respect to their local environments only.Emission measurements on vehicles powered by internalcombustion engines equipped with optimized exhaustpost-treatment systems have indicated the prospects the latter offer for cleaning up the environment, i.e., for yielding negative emissions, when run at their normal operating temperatures. Replacing electric cars with SULEV's is thus a matter currently under discussion. This paper will cover the functions of the various individual components of such post-treatment systems, and will show that optimizing the interactions among those components will improve their catalytic efficiencies. 10.5 sec. SULEV

Effect of temperature Ramp on hydrocarbon desorption profiles from zeolite ZSM‐12

“…Two important factors must be considered for the capture of HCs: the adsorption capacity of the adsorbent in the trap; and the desorption temperature, which must be above the minimum operating temperature of the catalyst. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] The maximum values of these factors are related to such solids properties as pore size, volume, structure, and surface area. Zeolites have been found to be the preferred adsorbents and the best candidates for this application, mainly due to their stability under severe process conditions and their thermodynamic affinity for absorbing HCs.…”

“…Placing HC traps before the TWC is the most common approach. Two important factors must be considered for the capture of HCs: the adsorption capacity of the adsorbent in the trap; and the desorption temperature, which must be above the minimum operating temperature of the catalyst . The maximum values of these factors are related to such solids properties as pore size, volume, structure, and surface area.…”

Development and application of a computer aided engineering methodology supporting the design optimization of automotive exhaust treatment systems

“…Several research studies have also shown that vehicles complying with current legislation in both EU and US, are able to certificate with future emission limits (Euro IV and SULEV) using current aftertreatment technology status, with special focal given to NOx emissions [9,11] . Of course, in order to achieve this goal, the complete system of engine, engine management and aftertreatment devices have to be optimized [18,19] . At the same time, there is an increasing interest and study in "off-cycle" emissions [20,21] as there are evidences that starting in lower temperatures or operating at higher speeds result in higher emission levels for vehicles that comply with legislation [17] .…”

“…Of course, the physical and the geometrical properties, the position of the catalytic converter in exhaust line and specific interactions with other devices and engine management affect the performance of the catalytic converter and consequently the tailpipe emissions. An indicative set of studies in this direction [18,73,36,37,38,39] pointed out the following optimization problems (washcoating excluded):…”