Paper M Sven Seifert, Dr. Francois Jayat, Alfred Reck. KVR Babu INTRODUCTION ABSTRACT. Emitec GmbH

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1 Paper M254 Benefits of LS-Design, a structured metal foil for two and three wheelers catalyst substrates, to minimize catalyst volumes, PGM loads and the route towards low NOx emissions Copyright 2 SAE India Sven Seifert, Dr. Francois Jayat, Alfred Reck Emitec GmbH KVR Babu Emitec Emission Control Technologies India Pvt. Ltd. - India ABSTRACT More efficient and durable catalytic converters for the two and three wheeler industry in developing countries are required at an affordable cost to reduce vehicle emissions, to maintain them at a low level and therefore to participate in a cleaner and healthier environment. This particularly is true nowadays, because the demand and prices of Platinum Group Metal (PGM) for catalyst are continuously increasing due to i) the world wide progressive implementation of motorcycles emission legislations similar to Euro 3 Stage requiring catalysts, ii) the need for non road Diesel vehicles to be equipped now with catalyst systems and iii) the constant increase of the world wide automobile market. A new generation of metallic substrates with structured foils for catalytic converters are proven to be capable of improving conversion behavior, even with smaller catalyst size. Specially developed foil structures, which transform a laminar exhaust gas flow into a turbulent one, significantly improve exhaust gas mixing behavior in the catalyst. This publication deals with the impact of turbulent substrate foil structure LS-Design on catalyst volume and PGM load compared to standard foils. Aged catalysts have been tested on engine test bench and vehicle roller bench, with a leading state of the art four stroke 5 cc motorcycle technologies developed for the Asian market. In comparison to the new proposed European motorcycle emission legislation stages EU 4, EU 5 and EU 6, an outlook about possible future Indian emission legislation stage after Bharat Stage III and possible consequences for the motorcycle technology is given. It is supported by results from an investigation, whose goal was to reduce further the NOx emissions of this state of the art motorcycle. INTRODUCTION The two and three wheeler vehicles with small displacement engines still remain the main transport mode, particularly in times of high petrol cost. Due to their high concentration in urban area, they are contributing to the degradation of air quality. Therefore highly efficient and durable exhaust gas catalytic converters for these vehicles are required to reduce their emissions and maintain them at a low level, in order to fulfill local emission legislation, thus contributing to a cleaner and healthier environment. Furthermore this must be done at affordable cost, at a time where PGM costs are continuously increasing due to an increasing demand and due to: The world wide progressive implementation of motorcycles emission legislations similar to Euro 3 Stage requiring catalysts. For example in China, more than 27 million motorcycles required a catalytic converter since 2 and around 4.7 millions motorcycles in Indonesia will do so in 23. The need for non road Diesel vehicles to be equipped now with catalyst systems with the introduction of Emission legislations stage EU IIIB (~ Tier4i) and Stage IV (~Tier 4) The constant increase of the world wide automobile market. A new generation of metallic substrates for catalytic converters with structured foils, which transform a laminar exhaust gas flow into a turbulent one and improve exhaust gas mixing behavior in the catalyst, has been developed with success and is mass-produced for

2 several passenger car and truck applications [,2,3]. These are also proved to be capable of improving conversion behavior of small catalysts for two wheelers [4,5] with engine displacements as low as 5 cm³ or as high as 99 cm³. The aim of this paper is, in a first part, to present the results of a technical measurement program with an Indian state of the art four stroke 5 cm³ motorcycle, homologated Bharat II which already meets Bharat III emission legislation, carried out at the Technical University of Graz: It is demonstrated that the catalyst volume and PGM Loading can be reduced thanks to the application of the LS-Design structured foil. These results will be discussed with regard to a theoretical quantification of the potential efficiency gain with LS- Design structured foil substrates. In a second part, with regard to new proposed European motorcycle emission legislation stages EU 4, EU 5 and EU 6, characterized by a further challenging reduction of the NOx emissions and a new World Harmonized Motorcycle (WMTC) driving cycle, the paper will present the results of an investigation aiming to reduce NOx emissions from the Indian 5 cc motorcycle, and thereafter draw a possible post Bharat III legislation stage. METAL TURBULENT STRUCTURED CATALYSTS It is a well known fact that catalyst effectiveness in warmed-up condition is influenced by substrate properties, i.e. by increasing the specific surface (the Geometric Surface Area: GSA) and improving contact between gas and wall, regardless of the type of catalytic reaction which takes place. This is characterized by the mass transfer coefficient β that describes the transport by diffusion of the pollutants from the core flow where their concentration is high to the catalytically active wall where their concentration is low. Flow conditions in Standard catalysts (Std) with straight and smooth channels are laminar after a first and short inlet section of the catalytic channel where the flow is not fully developed. Under laminar flow conditions the catalytic process is determined by a low mass transfer coefficient β, whose value could be five times lower than in the channel inlet section [6]. Beside the improvement of the mass transfer by mean of channel or cell size reduction, i.e. increasing the cell density for a given catalyst section, an innovative solution has been the development of turbulent metal substrates, whose foil structures introduced channel flow perturbations and therefore enhanced the mass transfer [6]. Of particular interest for the paper subject are the metal substrates with Longitudinal foil Structures (LS-Design ) LONGITUDINAL FOIL STRUCTURE (LS- DESIGN ) SUBSTRATES The substrate with longitudinal foil structure, applied in mass production [7], is characterized by LS-Counter corrugations (Figure ) built in the corrugated foil during the manufacturing process. The LS-Counter corrugations is formed by pushing a fraction of the corrugated foil into the centre of the channel, resulting in a local subdivision of the channel into two parts, aiming to recreate the inlet length like turbulent flow conditions, but also to bring the catalytically active wall to the centre of the flow where pollutant concentrations are higher. Therefore, and especially at low exhaust pollutant concentrations, the diffusion process is no longer limiting the mass transfer, which improves the total catalytic efficiency. Figure : LS-Design substrate structure LS-Design structured substrates had previously been presented in the year 99 [8,9] but no coating technologies for them were available at this time. Since the year 22 it has been possible to coat them and they are since 28 mass-produced for automotive applications. EXPERIMENTAL SETUP TEST VEHICLE The test vehicle is described in below Table. Test Vehicle Carburetion system Constant pressure carburetor Cooling system Air Exhaust gas after treatment Cold start system Transmission Vehicle reference mass [kg] Power output [kw at rpm] Three Way Catalyst (Ø4 x 6 mm, cpsi, 56 g/ft³ Pt/Rh = 5/) and secondary air induction for an exhaust gas Lambda value of about. [6] Hand choke 5 gears manual at 8 Homologation BHARAT II Table : Technical data of tested vehicle TEST SETUP Experimental setup details have been presented in [] for vehicle emission measurement and in [] for the emission measurements on engine test bench. The

3 Backpressure (mbar) original exhaust muffler has been modified in order to be able to change catalysts in the exhaust pipe several times and at the same time assure complete tightness of the exhaust system, while preserving its layout. In addition, five temperature sensors (three pre-catalyst, two post-catalysts) were inserted into the exhaust system (Figure 2). For the exhaust gas mixture condition analysis an oxygen sensor was mounted in the exhaust muffler. For emission measurements a gas sample extraction is carried out at the exhaust muffler outlet Std-22 LS-S-22 T muffler Catalyst series position T after catalyst T before catalyst Lambda T manifold 2 T manifold Mass Flow (kg/h) Figure 3: Backpressures of some tested catalysts at C Figure 2: Scheme of the exhaust system setup on tested vehicle TESTED CATALYST MATRIX All catalysts tested in this work have a diameter of 4 mm, a cell density of cpsi (cells per square inch) and a foil thickness of µm. Coating used at the time the test program was started is Platinum (Pt) - Rhodium (Rh) solution with a ratio Pt/Rh of 5/. Other characteristics of the catalysts presented in this paper are listed in Table 2. It can be seen that catalyst with LS-Design structured foils have a 5% reduced volume in comparison to Std catalysts. All catalysts have been hydro-thermally treated for 4 hours at 9 C in air. Catalysts names Std-22 Substrate type Cat. length [mm] Loadings [g/ft 3 ] 22 Std-4 Standard 6 4 Std LS-S LS-S-4 LS Design 5,8 4 LS-S Table 2: Matrix of tested catalysts Backpressure of LS structured catalysts and standard catalyst has been characterized. Results are presented in Figure 3. LS structured catalyst is giving a slightly increased backpressure in comparison to the standard catalyst, especially in the region 2 kg/h - 3 kg/h, representing the operating mass flow window over IDC and EDC. Figure 4, with the example of LS-22 catalysts, confirms the washcoat is well distributed. Figure 4: View of washcoat distribution in catalyst LS-22 (at LS counter corrugation level) PRELIMINARY RESULTS Preliminary emissions results in Indian (IDC) and European (ECE R4) Driving Cycles carried out according to the standard homologation procedures with fresh catalysts were presented in []. This preliminary study shows: The precious metal loading of the catalyst could be reduced with the help of the LS- Design structured foil metal substrates. The vehicle is very unstable due to its simple carburetor technology, which makes the emission data analysis more complex The use of fresh catalysts, due to their weak stability, could have contributed to the difficulty of the analysis. Then, results have been gained on engine test bench with aged catalysts []. The advantage of the measurement on engine test bench was the possibility to exchange the original engine carburetor system with a more sophisticated system allowing a strict control of the injected quantities of air and fuel, and then to correctly benchmark all tested catalysts. In parallel, the use of aged catalysts also eliminates the possible efficiency discrepancy resulting from unstable fresh catalysts. Three different engine operating points (Table 3), extracted from EDC were considered. The engine has been run in each operating point in lean (λ=.) and stoichiometric (λ=) modes.

4 HC Conversion rate (%) HC Conversion rate (%) CO Conversion rate (%) point # equivalent point in ECE R47 Transition st gear - 2 nd gear 2 Transition 2 nd gear - 3 rd gear 3 ~ 5 km/h - 3 rd gear Engine speed (rpm) Power (kw/h) Table 3: Description of the different engine loads. Figures 5 and 6 are showing HC and CO conversion rates for the standard and LS-S catalysts with three different PGM loadings in the three constant engine operating points run in lean mode, similar situation as in OEM configuration. The turbulent structure LS-Design improves the catalytic efficiency at reduced catalyst length (- 5%) and PGM loadings. Moreover it can be see that, at operating point #3 with the highest exhaust gas flow, conversion rates of standard catalysts are strongly limited by the diffusion process. In these flow conditions the influence of the PGM loadings is reduced. On contrary, LS-S catalysts overcome this diffusion limitation and show that even with the lower PGM loading 22g/ft³, LS-S catalyst performs better than Std-56 catalyst point # - 38 rpm point #2-5 rpm point #3-54 rpm Std-22 Std-4 Std-56 LS-S-22 LS-S-4 LS-S point # - 38 rpm point #2-5 rpm point #3-54 rpm Std-22 Std-4 Std-56 LS-S-22 LS-S-4 LS-S-56 Figure 6: Catalyst CO efficiencies at λ =. for LS- and standard type- catalysts. With a λ value of. no significant NOx conversion has been observed as expected. Therefore the three engine operating points have been run in stoichiometry mode (λ = ), in order to characterize the three way catalytic performances of the different catalysts. With the operating point #, exhaust gas temperatures were around 363 C and only low conversion rates below % - 5% for the three pollutants, whatever the catalyst structure and the PGM loading, have been observed. This can be explained by a non completed catalyst light off phase. Therefore, it was difficult to discriminate between both catalyst structures in these conditions. With operating points #2 and #3, exhaust gas temperatures are around 46 and 5 C, respectively, ensuring that catalysts have completed light off. Figures 7 to 9 are showing HC, CO and NOx conversion rates for the LS and Std catalysts for the operating point #3 with the higher exhaust gas mass flow Std Figure 5: Catalyst HC efficiencies at λ =. for LS- and standard type- catalysts. 3 2 LS-S 22 g/ft 4 g/ft³ 56 g/ft³ Figure 7: Catalyst HC efficiencies at λ = for LS- and standard type- catalysts at operating point #3.

5 NOx Conversion rate (%) CO Conversion rate (%) g/ft 4 g/ft³ 56 g/ft³ Std LS-S Figure 8: Catalyst CO efficiencies at λ = for LS- and standard type- catalysts at operating point #3. 7 Where: Where U: conversion rate C in, C out : inlet and outlet pollutant concentrations GSA: Surface Geometric Area (m²) V : Exhaust gas volume flow (m³/s)) : Mass transfer coefficient (m/s) Sh D 2 d h Equation (2) d h : Catalyst hydraulic diameter Std D 2: Binary diffusion coefficient Sh : Sherwood number g/ft 4 g/ft³ 56 g/ft³ LS-S The Sherwood number is a function of the catalyst data (length, cell density, foil thickness) and of the boundary conditions (temperature, flow velocity and pressure). Recently computational model for Sherwood numbers have been determined for LS-Design structured foil catalysts, based on a large scale laboratory test program with the model reaction of propene oxidation [2]. Figure 9: Catalyst NOx efficiencies at λ = for LS- and standard type- catalysts at operating point #3. It can be seen in these conditions that LS catalysts with reduced volume outperformed the standard catalyst for all PGM Loadings, the effects being clearer by CO and NOx conversion rates at low PGM loadings. More particularly, LS catalyst with 4 g/ft³ PGM almost performed the same than the Standard catalyst with 56 g/ft³ PGM in these conditions. This means same emission results with an absolute PGM reduction of 4% in this case. EFFECTIVENESS IMPROVEMENT WITH TURBULENT METAL SUBSTRATES Under mass transfer limited conditions, catalyst effectiveness is characterized by the emission-relevant product β x GSA as it can be seen in Equation (). c U c out in exp GSA. V Equation () Then β values and consequently the product ß x GSA for LS substrates can be calculated. Therefore it was of interest to compare the product ß x GSA for the catalysts considered in this paper, independently from the PGM loading, in order to evaluate the potential of both substrate types. It also was interesting to compare cpsi LS substrate to a 2 cpsi Std metal substrate of same volume, that also could be used to improve the converter performances. This comparison is carried out in the application conditions over IDC and EDC. Figure shows the computational product ß x GSA for the three catalyst types as a function of the channel gas flow velocity, derived from the engine speed. It can be seen that the product ß x GSA increases more strongly with the exhaust gas mass flow for LS catalyst than for Std catalyst. The product values for LS catalyst are always higher than the one for the Std catalyst, and are.5 to 2 times higher above a channel gas flow velocity of 6 m/s, corresponding to engine idle conditions. Above this velocity, the LS substrate also exhibits a higher product ß x GSA than the 2 Std catalyst. This suggests that the LS potentially would perform better than the 2 Std and Std catalyst.

6 ß. GSA Speed (km/h), Inlet T ( C), Engine Speed (rpm/5) ß. GSA Speed (km/h), Inlet T ( C), Engine Speed (rpm/5) ß. GSA The higher efficiencies of LS catalysts, presented in the chapter preliminary results, gained at three engine operating points (Table 3), with channel exhaust gas flow velocities of m/s, 6.8 m/s and 9 m/s, respectively, confirmed this theoretically higher potential of LS substrates catalysts: Std µm, 2 Std 8 µm and LS µm as a function of IDC testing time. The fifth cycle unit, corresponding to the start of emission sampling for measurement, is here considered. Figure and Figure 2 illustrate the potential of the LS catalyst in comparison to the Std catalyst. Excepted at idle, the LS catalyst has a product ß x GSA almost two times higher. It can be seen that the LS catalyst also would perform better than the 2 Std catalyst at all engine speeds excepted at idle. These computational results are indicating that the LS catalyst, with a reduced volume, potentially would better perform than the reference Std catalyst Exh. Gas Flow Velocity (m/s) LS mm, L=5.8 mm.2 4 Std µm, L=6 mm 2 Std 8 µm, L=5.8 mm.5 3 Figure : Calculated β x GSA values for three metal catalysts: Std µm, 2 Std 8 µm and LS µm as a function of Channel gas flow velocity in IDC (cycle unit #5) and EDC (cycle unit #5) conditions EDC Time (s) LS mm, L=5.8 mm Std µm, L=6 mm 2 Std 8 µm, L=5.8 mm Inlet T ( C) Speed (km/h) engine Speed (rpm/5) IDC Time (s) LS mm, L=5.8 mm Std µm, L=6 mm 2 Std 8 µm, L=5.8 mm Inlet T ( C) Speed (km/h) engine Speed (rpm/5) Figure : Calculated β x GSA values for three metal Figure 2: Calculated β x GSA values for three metal catalysts: Std µm, 2 Std 8 µm and LS µm as a function of EDC testing time. The third cycle unit of EDC (where catalysts must be light off) is here considered. VEHICLE EMISSION RESULTS According to the results of Figures 5-9 and the theoretically evaluation of LS performance potential, it would be interesting to measure the efficiency of the aged LS-S-4 catalyst in vehicle emission tests and compare it to Std-56 catalyst. This would let us know if,

7 Tail Pipe Emission (g/km) Tail Pipe HC Emission (ppm) Tail Pipe HC Emission (ppm) Tail Pipe HC Emission (ppm) in parallel to a volume reduction, a PGM loading reduction is possible (absolute 4% PGM reduction). MEASUREMENTS OVER IDC Figure 3 presents the Hydrocarbon (HC) emissions after the LS and STD catalysts and Figure 4 presents the bag result over IDC. The results confirm the potential for LS catalyst to improve the catalyst efficiency over IDC and furthermore suggest that the PGM loading could be further reduced for the LS catalyst, because LS catalyst with 4 g/ft³ outperforms the Std catalyst with 56 g/ft³ in IDC conditions MEASUREMENTS OVER EDC Figures 5 and 6 are showing the influences of the catalyst types on the tail pipe HC emission over two EDC cycle units EDC Time (s) speed Dummy EDC Time (s) speed Dummy Std - 56 LS-S 4 Figure 3: Catalyst influences on tail pipe hydrocarbon emissions over IDC testing time. The fifth cycle unit of IDC is here considered. Std - 56 LS-S 4 Figure 5: Catalyst influences on tail pipe hydrocarbon emissions over of EDC testing time. The third cycle unit of EDC is here considered ,4,2,8,6 HC CO HC + Nox EDC Time (s),4 speed Dummy,2 Std - 56 LS-S 4 Dummy Std - 56 LS-S 4 Figure 6: Catalyst influences on tail pipe hydrocarbon emissions over of EDC testing time. The sixth cycle unit of EDC is here considered. Figure 4: Catalyst Influence on bag emissions over IDC. The HC emission reduction advantage seen in Figure 5 for LS catalyst can be explained by its better light off

8 Tail Pipe HC Emission (ppm) Tail Pipe Emission (g/km) performance (Figure 8). Over the sixth and last EDC cycle unit, the Std catalyst is warm enough to catch up the efficiency level of the LS catalyst. These results confirm the theoretical potential of LS catalyst described before. These results also show that the PGM load of 4 g/ft³ for the LS catalyst could not be further reduced in EDC conditions that are characterized by higher engine loads than in IDC conditions. THE ROAD TO LOWER NO X EMISSION With regard to new proposed European motorcycle emission legislation stages EU 4, EU 5 and EU 6, characterized by a further challenging reduction of the NOx emissions and a new WMTC driving cycle, it could be of general interest to investigate what could be the next emissions legislation stage after BS 3.,6,4,2,8,6,4,2 HC CO NOx Dummy Std - 56 LS-S 4 NOx emission reduction for this Indian vehicle looks very challenging according to the above presented emission measurement results. On other hand, motorcycles with engine displacement below 5 cc with similar engine technologies are fulfilling China 3 (equivalent to EURO 3). Looking closely to the applied technical solutions, it can be observed that the engines are calibrated more rich, reducing by this mean the temperature in the combustion chamber and consequently the NOx production, but increasing HC and CO emissions and the fuel consumption. The related catalytic converters have an increased volume and use a higher cell density (3 cpsi for example). Depending on the engine out NOx emissions, two catalytic converter designs are used: Figure 7: Catalyst Influences on Bag emissions over EDC EDC Time (s) speed Dummy Std - 56 LS-S 4 Figure 8: Catalyst influences on tail pipe hydrocarbon emissions during cold start in ECE. EDC Bag results show same HC tail pipe emissions for Std and LS-S catalyst (Figure 7). This could be explained by some more HC engine out emissions during the cold start (Figure 8). LS Catalyst still shows an advantage for the reduction of CO. As expected almost no NOx conversion is observed, indicating this Indian motorcycle doesn t fulfilled Euro 3 limit (.5 g/km). If engine out NOx emissions lower than Emission limit: Secondary air induction + Oxidation catalyst (~ ml) for HC and CO treatment. If engine out NOx emissions higher than Emission limit: TWC catalyst (~ ml) for the reduction of NOx + secondary air induction + Oxidation catalyst (~ ml) for HC and CO treatment. This tells, with the assumption of a possible future convergence of Indian emission legislation with European legislation (BS 4 at least equivalent to EURO 3 for example, where NOx emission limit is.5 g/km over EDC), that the catalytic converter could be much more costly with the application of bigger catalyst volumes and higher cell densities. Hence it is proposed to try another option for the catalytic converter design on the Indian testing vehicle. The catalyst is moved to a position closer to the engine at the location of the thermocouple T manifold 2 in Figure 2. In this location exhaust gas temperature is around C higher than temperatures at series catalyst inlet position. If the NOx reduction reaction is temperature limited as the preliminary results indicated, it could be hypothesized that the so-called close coupled (CC) catalyst offers a certain NOx emission reduction potential. Bag emission results over EDC are presented in Figures 9 2. These figures show that the LS-S-4 catalyst in CC position outperforms the Std-56 catalyst for all pollutants. Figure 9 shows a positive influence of the structured metal foil with LS-Design in CC position on NOx emissions. EURO 3 limit is fulfilled with this catalyst only. Figure 2 shows very little influence of the catalyst position towards the engine on the CO emissions, while

9 Tail Pipe HC Emission ( g/km) Tail Pipe CO Emission (/ g/km) Tail Pipe NOx Emission (g/km) Tail Pipe NOx Emission (g/km) Figure 2 shows a very big influence of the close coupled position on the HC emissions for both catalysts EURO 3 Std - 56 LS-S 4 CC-Std - 56 CC-LS- S 4 Figure 9: Catalyst position influences on Bag NOx emissions over EDC EURO 3 Std - 56 LS-S 4 CC-Std - 56 CC-LS-S 4 Figure 2: Catalyst position influences on Bag CO emissions over EDC EURO 3 Std - 56 LS-S 4 CC-Std - 56 CC-LS-S 4 Figure 2: Catalyst position influences on Bag HC emissions over EDC. temperatures over IDC, where the engine load is lower, and a low catalyst volume, a non significant NOx emissions reduction has been observed only (Figure 22) Std - 56 LS-S 4 CC-Std - 56 CC-LS-S 4 Figure 22: Catalyst position influences on Bag NOx emissions over IDC. These results indicate that the installation of the catalyst in a close coupled position, combined with the use of LS- Design structured metal foil, allows the BS II certified testing vehicle to fulfill EURO 3 legislation. But would it fulfill EURO III over the new Word Harmonized Motorcycle Driving cycle (WMTC)? This still has to be checked in our next testing campaign. Today similar series vehicle produced.444 g/km NOx over WMTC [3]. This is twice the WMTC limit value and the NOx quantity produced over EDC. Simply considering this NOx emission doubling from EDC to WMTC, the presented system with the LS catalyst in CC position would deliver 8% of the NOx emission limit. Therefore an increase of the catalyst volume might be required to increase the catalytic efficiency during the second part of the WMTC with high load. Then, if not enough, the engine could be tuned to a slightly richer mode, which has a big positive influence on NOx emission reduction at the expense of CO emissions as shown in Figure 23. Then, the close coupled position and the structured metal substrate with LS-Design represent together a possible development route for new exhaust gas aftertreatment system. By taking advantages of higher exhaust gas temperatures this exhaust gas converter would fulfill more severe emission legislations and particularly lower NOx emission limits and keep the solution cost at a reasonable level. After that, emission measurements in CC position over IDC were carried out to check its potential. Unfortunately, most probably due to the lower exhaust gas

10 Tail Pipe Emission (g/km) HC CO/ NOx pipe emission (g/km) of HC (-35%), CO (-25%), HC + NOx (-24%), which indicates a potential absolute 4% PGM reduction in comparison to the standard catalyst EURO 3 Series calibration Rich tuned calibration Figure 23: Influence of a rich tuned engine on emissions over EDC. LS-S-4 Catalyst in close coupled position. (5) Vehicle emission results over the EDC show same HC tailpipe emission for LS-Design with 4 g/ft³ and the standard catalyst with 56 g/ft³ PGM while there is an advantage for LS-Design on CO reduction by -3%. As expected, no NOx conversion is observed, indicating this Indian motorcycle does not fulfill Euro 3 limit of.5 g/km. (6) To meet the required Euro 3 NOx emission target of.5 g/km the potential of LS-Design with 4 g/ft³ PGM loading has shown the capability of.3 g/km for tail pipe NOx emissions in case the catalyst is positioned closer to the engine to benefit from higher temperature. CONCLUSION Structured foil based catalysts, especially the LS- Design show high potential for cost reduction of the exhaust system due to higher conversion efficiency by using smaller substrate dimensions. Higher turbulence in the substrate causes higher mass transfer rates resulting in less loading and the possibility for less use of precious metal. Six different catalysts, three standard and three LS- Design ones with same precious metal loadings and a reduced length by -5% for the LS-Design have been tested according the backpressure and emissions efficiency for HC, CO and NOx comparing the Indian IDC and European EDC drive cycles for motorcycles. Achievements of this research using an Indian State of the Art four stroke 5 cc motorcycle can be summarized as follows: () LS-Design structured catalysts are showing a slightly increased backpressure in comparison to the standard catalyst in the region of 2 kg/h to 3 kg/h mass flow. (2) LS-Design catalysts with 22 g/ft³ loading show even better performance on HC (+7%) and CO (+9%) at λ=. than standard catalysts with 56 g/ft³ loading, at higher exhaust gas flow. No significant NOx conversion has been observed as expected at λ=.. (3) LS-Design catalysts with 4 g/ft³ PGM almost perform the same than the standards catalysts with 56 g/ft³ at λ= and higher exhaust gas flow for HC, CO and NOx conversion rates. (4) Vehicle emission results over the IDC show an outperformance of the LS-Design with 4 g/ft³ vs. the standard catalyst with 56 g/ft³ PGM according tail ACKNOWLEDGMENTS Special thanks to Dr. G. M. Bickle for proof-reading. REFERENCES. M. Ganz, S. Hackmayer, quattro GmbH, C. Kruse, A. Reck, Emitec GmbH Innovatives Katalysatorsystem für den Audi RS6, 8 Zyl, 4,2ltr, 33 KW mit LEV Zertifizierung, Wiener Motoren Symposium, April C. Lotti, V. Rossi, L. Poggio, Ferrari S.p.A.; M. Holzinger, ArvinMeritor; L. Pace, M. Presti, EMITEC GmbH: Backpressure Optimized Close Coupled PE Catalyst - First Application on a Maserati Powertrain, SAE M. Bollig, J. Liebl, R. Zimmer :BMW Group; M. Kraum, O. Seel, S. Siemund :Engelhard Technologies GmbH ; R. Brück, J. Diringer, W. Maus : Emitec GmbH: "Next generation catalysts are turbulent:development of support and coating", SAE A. Reck, F-W Kaiser, M.D. Nguyen (EMITEC): M. Korman, R. Kirchberger, M. Hirz (GUT): Metallic Substrates for Catalytic Converters in 2 & 3 Wheelers / Turbulent Catalysts meet the Requirements of the Future, VSAE Paper B. VAN EICKELS, H.-P. DUMMANN, KTM Sportmotorcycles AG, L. PACE, A. RECK, Emitec GmbH: Innovative Metallic Substrate Technology to Meet Future Emission Limits, SETC , SAE Brueck R., Hirth P., Maus W., Deutschmann O., Mladenov N., Fundamentals of Laminar and Turbulent Catalysis; Turbulent beats Laminar, 27. Internationales Wiener Motorensymposium, 26

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