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Viewing 31 to 60 of 24398
2017-03-28
Technical Paper
2017-01-0945
Markus Dietrich, Carsten Steiner, Gunter Hagen, Ralf Moos
State of the art for NOx reduction for low- and heavy-duty diesel engines is the ammonia SCR technique. Today’s SCR control approaches are model-based, relying on NOx sensors and the ammonia-providing urea dosing module. Based on model uncertainties, low ammonia storage levels on the catalyst surface are aimed to avoid ammonia slip. This leads to the disadvantage of catalyst oversizing or that the maximum catalytic potential is not exploited. The radio-frequency (RF) or microwave based catalyst state determination offers the ability to operate automotive catalysts at its optimal point. By using the catalyst canning as a resonator, knowledge about the electric properties of the catalyst can be derived from its resonance parameters. Their direct correlation to the catalyst state has already been proven for the oxidation state of a TWC, the soot loading on a DPF/GPF and the ammonia storage on vanadium and zeolite based SCR catalysts.
2017-03-28
Technical Paper
2017-01-0695
Ezio Spessa, Stefano D'Ambrosio, Daniele Iemmolo, Alessandro Mancarella, Roberto Vitolo, Gilles Hardy
In order to meet the continuously stringent standards in terms of pollutant emissions and fuel consumption from combustion engines of road vehicles, several investigations have been recently conducted about in-cylinder techniques and aftertreatment systems. In particular, the control of the fuel injected quantity and of the center of combustion (MFB50) performed cylinder-by-cylinder can effectively provide advantages in terms of pollutant formation and fuel consumption. In the present investigation, an experimental comparison among different control strategies is performed in a heavy-duty 3.0 L Euro VI diesel engine. The first control strategy is the standard one originally implemented in the ECU, whereas the other two are referred to as model-based and pressure-based combustion controls and have been implemented by means of rapid prototyping and proper hardware device connected to the ECU.
2017-03-28
Technical Paper
2017-01-0583
Farraen Mohd Azmin, Phil Mortimer, Justin Seabrook
With the introduction in Europe of drive cycles such as RDE and WLTC, transient emissions prediction is more challenging than for the NEDC. Transient predictions are used in the calibration optimisation process to determine the cumulative cycle emissions for the purpose of meeting objectives and constraints. Predicting emissions such as soot accurately is the most difficult area, because soot emissions rise very steeply during certain transients. Besides model accuracy, prediction time also is also important when applying a dynamic model because the optimisation process can take a significant amount of time to converge to a solution that satisfies all constraints. The method proposed in this paper is an evolution of prediction using a steady state global model. A dynamic model can provide the instantaneous prediction of boost and EGR that a static model cannot. Meanwhile, a static model is more accurate for steady state engine emissions.
2017-03-28
Technical Paper
2017-01-0930
Christine K. Lambert, Timothy Chanko, Mark Jagner, Jon Hangas, Xin Liu, James Pakko, Carl Justin Kamp
To meet future particle mass and particle number standards, gasoline vehicles may require particle control, either by way of an exhaust gas filter and/or engine modifications. Soot levels for gasoline engines are much lower than diesel engines; however, non-combustible material (ash) will be collected that can potentially cause increased backpressure, reduced power, and lower fuel economy. The purpose of this work was to examine the ash loading of gasoline particle filters (GPFs) during rapid aging cycles and at real time low mileages, and compare the filter performances to both fresh and very high mileage filters. Current rapid aging cycles for gasoline exhaust systems are designed to degrade the three-way washcoat both hydrothermally and chemically to represent full useful life catalysts. The ash generated during rapid aging is low in quantity although similar in quality to real time ash. Filters were also examined after a low mileage break-in of approximately 3000 km.
2017-03-28
Technical Paper
2017-01-1296
David Charles Weber, Yimin Liu, Perry MacNeille
The future of sustainable transportation is to use as much electric power as possible that is derived from sustainable sources (e.g. solar, wind, hydro). This paper evaluates the benefits of trains of vehicles that are mechanically connected together for long distance travel as a means to the attainment of coast-to-coast travel using only electric power. The technical challenges are examined.
2017-03-28
Technical Paper
2017-01-0924
Jan Schoenhaber, Nikolas Kuehn, Bastian Bradler, Joerg Michael Richter, Sascha Bauer, Bernd Lenzen, Christian Beidl
Recently, the European Union has adopted a new regulation on Real-Driving-Emissions (RDE) and also China is considering RDE implementation into the China 6 legislation. This new regulation is focused on measuring nitrogen oxides (NOx) and particulate number (PN) emissions of both light-duty gasoline and diesel vehicles under real world conditions. A supplemental RDE test procedure was developed for European type approval, which includes on-road testing with cars equipped with portable emission measurement systems (PEMS). This additional requirement will significantly affect the engine calibrations and the exhaust gas aftertreatment. In this study the impact of the new RDE regulation on two recent EU6b certified turbocharged direct injected gasoline vehicles has been investigated. A comparison of several chassis dyno drive cycles with two new defined on-road RDE trips was performed.
2017-03-28
Technical Paper
2017-01-0953
Jinyong Luo, Yadan Tang, Saurabh Joshi, Krishna Kamasamudram, Neal Currier, Aleksey Yezerets
Selective Catalytic Reduction of nitrogen oxides (NOx) with NH3 is a leading technology for lean-burn engines to meet the increasingly stringent environmental regulations worldwide. Among various SCR catalysts, Cu/CHA catalysts have been widely used in the industry, due to their desirable performance characteristics including their unmatched hydrothermal stability. While broadly recognized for their outstanding activity at or above 200oC, these catalysts may not show desired NOx conversion at lower temperatures. To achieve high NOx conversions it is desirable to have NO2/NOx close to 0.5 which is possible to achieve by DOC selection and optimization of its location. However even under such optimal gas feed conditions, sustained use of Cu/CHA below 200C leads to ammonium nitrate formation and accumulation leading to the inhibition of NOx conversion. In addition, the decomposition of accumulated NH4NO3 will lead to the formation of N2O, an undesired greenhouse gas.
2017-03-28
Technical Paper
2017-01-0674
Benjamin Matthew Wolk, Isaac Ekoto
Pulsed nanosecond discharges (PND) can achieve ignition in internal combustion engines through enhanced reaction kinetics as a result of elevated electron energies without the associated increases in translational gas temperature that cause electrode erosion. Atomic oxygen (O), including its electronically excited states, is thought to be a key species in promoting low-temperature ignition. In this paper, high-voltage (17-24 kV peak) PND are examined in oxygen/nitrogen/carbon dioxide/water mixtures at engine-relevant densities (up to 9.1 kg/m^3) through pressure-rise calorimetry and direct imaging of excited-state O-atom and molecular nitrogen (N2) in an optically accessible spark calorimeter, with the anode/cathode gap distance set to 5 mm or with an anode-only configuration (DC corona). The conversion efficiency of pulse electrical energy into thermal energy was measured for PND with secondary streamer breakdown (SSB) and similar low-temperature plasmas (LTP) without.
2017-03-28
Technical Paper
2017-01-0962
Jian Gong, Di Wang, Avra Brahma, Junhui Li, Neal Currier, Aleksey Yezerets, Pingen Chen
Three-way catalysts (TWCs) have been widely used on stoichiometric gasoline and natural gas engines for CO, hydrocarbons and NOx emissions control. Oxygen storage capacity (OSC) is a critical factor of a TWC and is closely related to the catalyst aging and performance. On natural gas engine aftertreatment development, on-board diagnostic (OBD) is required and OSC monitoring is the primary TWC OBD method. A dynamic OSC model involving two storage sites with distinct kinetics was developed and validated on the engine. The validated OSC model was utilized to study the effects of engine operating conditions (oxygen concentration and space velocity) on lean breakthrough OSC (OSB), which is monitored through OBD. Base on the simulation analysis, it was found that OSB is not a constant for a particular TWC catalyst and is dependent on space velocity and oxygen concentration.
2017-03-28
Technical Paper
2017-01-0935
Christoph Boerensen, Dirk Roemer, Christian Nederlof, Evgeny Smirnov, Frank Linzen, Felix Goebel, Brendan Carberry
The biggest challenge in emission control for compression ignited internal combustion engines is the suppression on NOx. In the US, NOx-levels have been regulated strictly for a long time, but recently the introduction of the real-world-driving legislation (RDE) aggravated the requirements in Europe dramatically; they can only be fulfilled by a system, that operates robustly under all driving conditions. Emission control is based on engine-internal optimizations to reduce the feedgas in conjunction with aftertreatment technologies, that are generally selective catalytic reduction (SCR) or lean NOx traps (LNT) based systems. Due to its ability to control high amounts of NOx, SCR is widely used in heavy-duty applications and is becoming more popular in light-duty and passenger car applications as well.
2017-03-28
Technical Paper
2017-01-0931
Michiel Van Nieuwstadt, Joseph Ulrey
While not commonly in production today, Gasoline Particulate Filters (GPFs) are likely to see widespread deployment to meet stringent EU6.2 and China particulate number (PN) standards. In many ways the operating conditions for GPFs are orthogonal to those of their diesel counterparts, and this leads to different and interesting requirements for the control strategy. We will present some generic system architectures for exhaust systems containing a GPF and will lay out an architecture for the GPF control strategy components which include: regeneration assist feature, soot estimation algorithm, GPF protection. Lastly, we will show validation data of the control strategy under different operating conditions.
2017-03-28
Technical Paper
2017-01-0602
Vladimir Vasilije Kokotovic, Colby Buckman
Abstract – Vehicle accessories electrification trend comes with new control concepts that in many cases frees up the direct engine drives. Considering that direct engine drives do not have as much flexibility as independent electric drives, it is apparent that several advantages are to be expected form electric drives. New developed high efficient electric drives can be implemented with the consideration of better fuel economy, end better performance in different engines operating regimes. In some cases that is achieved with better Start up procedure, Pressure, Flow, ”On Demand” features, or more intensive cooling when is needed (cooling “On demand”), power “On Demand”,… Electrification trend should be seen as an opportunity not only for better performance but also for better fuel economy.
2017-03-28
Technical Paper
2017-01-0939
Ashok Kumar, Krishna Kamasamudram, Neal Currier, Aleksey Yezerets
Copper and iron-zeolite SCR catalysts are widely used in US and European diesel after-treatment system to achieve drastic reduction in NOx emissions. The type of transition metal ion in zeolite has a significant impact on their key performance and durability characteristics including the response to sulfur containing exhaust gas. In this article, we made an attempt to address the impact of only the transition metal ion on various SCR catalytic functions, by using a single source of zeolite BEA in the preparation of H-, Fe- and Cu-BEA samples. Similar molar amounts of copper and iron were ion-exchanged into H-BEA and washcoated on the cordierite support by Johnson Matthey Inc. Below 300C, Fe-BEA showed lower NOx conversion than Cu-BEA despite the former catalyst more active for NO oxidation to NO2, a potential reaction intermediate. Upon sulfation, the NOx reduction activity of Cu-BEA degraded much more than Fe-BEA SCR catalysts.
2017-03-28
Technical Paper
2017-01-0950
Alexander Sappok, Paul Ragaller, Andrew Herman, Leslie Bromberg, Vitaly Prikhodko, James Parks, John Storey
The increasing use of diesel and gasoline particulate filters requires advanced on-board diagnostics (OBD) to prevent and detect filter failures and malfunctions. Early detection of upstream (engine-out) malfunctions is paramount to preventing irreversible damage to downstream aftertreatment system components. Such early detection can mitigate the failure of the particulate filter resulting in the escape of emissions exceeding permissible limits and extend the component life. However, despite best efforts at early detection and filter failure prevention, the OBD system must also be able to detect filter failures when they occur. In this study, radio frequency (RF) sensors were used to directly monitor the particulate filter state of health for both gasoline particulate filter (GPF) and diesel particulate filter (DPF) applications.
2017-03-28
Technical Paper
2017-01-0955
Hai-Ying Chen, Donna Liu, Erich Weigert, Lasitha Cumaranatunge, Kenneth Camm, Patrick Bannon, Julian Cox, Louise Arnold
The phase-in of US EPA Tier 3 and California LEV III emission standards require further reduction of tailpipe criteria pollutants from automobiles. At the same time, the mandate for reducing Green House Gas (GHG) emissions continuously lowers the exhaust temperature. Both topics pose significant challenges to emission control catalyst technologies, especially for cold start emissions. The recently developed diesel cold start concept technology (dCSC™) shows promising results. It stores NOx and HC during the cold start period until the downstream catalytic components reach their operating temperatures, when the stored NOx/HC are subsequently released and converted. The technology also has oxidation functions built in and acts as a diesel oxidation catalyst under normal operating conditions. In a US DOE funded project, the diesel cold start concept technology enabled a high fuel efficiency vehicle to achieve emissions targets well below the SULEV30 emission standards.
2017-03-28
Technical Paper
2017-01-0714
Qinglong Tang, Haifeng Liu, Mingfa Yao
Reactivity controlled compression ignition (RCCI) is a potential combustion strategy to achieve high engine efficiency with ultra-low NOx and soot emissions. Fuel stratification can be used to control the heat release rate of RCCI combustion. But the in-cylinder combustion process of the RCCI under different fuel stratification degrees has not been well understood, especially at a higher engine load. In this paper, simultaneous measurement of natural flame luminosity and emission spectra was carried out on a light-duty optical RCCI engine under different fuel stratification degrees. The engine was run at 1200 revolutions per minute under a load about 7 bar indicated mean effective pressure (IMEP). In order to form fuel stratification degrees from low to high, the common-rail injection timing of n-heptane was changed from -180° CA after top dead center (ATDC) to -10° CA ATDC, while the iso-octane delivered in the intake stroke was fixed.
2017-03-28
Technical Paper
2017-01-0123
Saiful Bari
In general, diesel engines have an efficiency of about 35% and hence, a considerable amount of energy is expelled to the ambient air. In water-cooled engines, about 25%, 33% and 7% of the input energy are wasted in the coolant, exhaust gas, and friction, respectively. The heat from the exhaust gas of diesel engines can be an important heat source to provide additional power and improve overall engine efficiency. Studies related to the application of recoverable heat to produce additional power in medium capacity diesel engines (< 100 kW) using separate Rankine cycle are scare. To recover heat from the exhaust of the engine, an efficient heat exchanger is necessary. For this type of application, the heat exchangers are needed to be designed in such a way that it can handle the heat load with reasonable size, weight and pressure drop. This paper describes the study of a diesel generator-set attached with an exhaust heat recovery system.
2017-03-28
Technical Paper
2017-01-0160
Longjie Xiao
In the background of the increasing amount of car ownership in the world, the amount of heat that is not utilized in automobile exhaust should not be ignored, and the importance of using automobile exhaust gas for power generation is gradually being realized and valued by people. However, the urban traffic environment is changeable. The frequent start and stop as well as the acceleration and deceleration of the car will lead to the fluctuation of gas temperature and flow and then the temperature fluctuation of the thermoelectric module’s hot end, which reduces the power generation efficiency of thermoelectric module. By arranging the heat conduction oil circulation at the hot end, the temperature fluctuation of the hot end of thermoelectric module can be effectively reduced, but the system volume is large, and the working fluid circulation needs additional energy supply.
2017-03-28
Technical Paper
2017-01-0593
Ivan Arsie, Rocco Di Leo, Cesare Pianese, Matteo De Cesare
The development of more affordable sensors together with the enhancement of computation features in current Engine Management Systems (EMS), makes the in-cylinder pressure sensing a suitable methodology for the on-board engine control and diagnosis. Since the 1960’s the in-cylinder pressure signal was employed to investigate the combustion process of the internal combustion engines for research purposes. Currently, the sensors cost reduction in addition to the need to comply with the strict emissions legislation has promoted a large-scale diffusion on production engines equipment. The in-cylinder pressure signal offers the opportunity to estimate with high dynamic response almost all the variables of interest for an effective engine combustion control even in case of non-conventional combustion processes (e.g. PCCI, HCCI, LTC).
2017-03-28
Technical Paper
2017-01-0795
Changhoon Oh, Wai K. Cheng
The gasoline direct injection engine (GDI) particulate emission sources are assessed under cold start conditions: the fast idle and speed/load combinations representative of the 1st acceleration in the US FTP. The focus is on the accumulation mode particle number (PN) emission. The sources are non-fuel, combustion of the premixed charge, and liquid fuel film. The non-fuel emissions are measured by operating the engine with premixed methane/air or hydrogen/air. Then the PN level is substantially lower than what is obtained with normal GDI operation; thus non-fuel contribution to PN is small. When operating with stoichiometric premixed gasoline/air, the PN level is comparable to the non-fuel level; thus premixed-stoichiometric mixture combustion does not significantly generate particulates. For fuel rich premixed gasoline/air, PN increases dramatically when lambda is less than 0.7 to 0.8.
2017-03-28
Technical Paper
2017-01-0796
J. Felipe Rodriguez, Wai K. Cheng
The NOx emissions during the crank-start and cold fast-idle phases of a GDI engine are analyzed in detail. The NOx emissions of the first 3 firing cycles are studied under a wide set of parameters including the mass of fuel injected, start of injection, and ignition timing. The results show a strong dependence of the NOx emissions with injection timing, and they are significantly reduced as the mixture is stratified. The impact of different valve timings on crank-start NOx emissions was analyzed. Late intake and early exhaust timings show similar potential for NOx reduction; 26-30% lower than the baseline. The combined strategy, resulting in a large symmetric negative valve overlap, shows the greatest reduction; 59% lower than the baseline. The cold fast-idle NOx emissions were studied under different equivalence ratios, injection strategies, combustion phasing, and valve timings. Slightly lean air-fuel mixtures result in a significant reduction of NOx.
2017-03-28
Technical Paper
2017-01-1002
Daisuke Tanaka, Ryo Uchida, Toru Noda, Andreas Kolbeck, Sebastian Henkel, Yannis Hardalupas, Alexander Taylor
Reducing engine-out particulates is one of the main issues of direct injection gasoline engines and further efforts are still needed to comply with near-future emission regulations. However, engine-out particulate emission characteristics strongly depend on fuel properties associated with the combustion design and/or calibration, due to the complicated mechanisms of particulate formation, including both physical and chemical processes. For these reasons, the purpose of this work was to gain a fundamental understanding of which fuel property parameters are responsible for particulate emission characteristics, associated with key intermediate behavior in the engine cylinder. Accordingly, engine tests were carried out using various fuels having different volatility and chemical compositions under different coolant temperature conditions. In addition, a fundamental spray and film visualization analysis was also conducted using a constant volume vessel.
2017-03-28
Technical Paper
2017-01-0702
Raouf Mobasheri, Mahdi Seddiq
The simultaneous effects of pilot fuel quantity and pilot injection timing on engine performance and amount of pollutant emission have been computationally investigated in a High Speed Direct Injection (HSDI) diesel engine. In this study, a modified parameter called “Homogeneity Factor of in-cylinder charge (HF)” has been applied to analyze the air-fuel mixing and combustion processes. For this purpose, the simulated results has been firstly compared with the experimental data and a good agreement has been achieved for simulating the in-cylinder pressure and the amount of pollutant emissions. Then, nine different strategies based on two variables (the amount of fuel mass in pilot and main injection as well as the dwell between two injections) have been investigated. The results show that employing pilot injection results in higher in-cylinder temperature and shorter auto-ignition delay which causes a rapid increase in the rate of NOx formation in early stage of combustion process.
2017-03-28
Technical Paper
2017-01-0601
Huayi Li, Kenneth Butts, Kevin Zaseck, Dominic Liao-McPherson, Ilya Kolmanovsky
The development of advanced model-based engine control strategies, such as economic model predictive control (eMPC) for diesel engine fuel economy and emission optimization, requires accurate and low-complexity models for online prediction and controller validation. This paper presents the NOx and smoke emissions modeling of a light duty diesel engine equipped with a variable geometry turbocharger (VGT) and a high pressure exhaust gas recirculation (EGR) system. Such emission models can be integrated with an existing air path model into a complete engine mean value model (MVM), which can predict engine behavior at different operating conditions for controller design and validation before physical engine tests. The NOx and smoke emission models adopt an artificial neural network (ANN) approach with multi-layer perceptron (MLP) architectures. The networks are trained and validated using experimental data collected from engine bench tests.
2017-03-28
Technical Paper
2017-01-0604
Christian Friedrich, Yves Compera, Matthias Auer, Gunnar Stiesch, Georg Wachtmeister
Improving fuel efficiency while meeting relevant emission limits set by emissions legislation, are among the main objectives of engine development. Simultaneously the development costs and development time have to be reduced steadily. For these reasons high demands regarding quality and validity of measurements at the engine test bench are rising continuously. In this paper a new methodology for efficient testing of an industrial combustion engine in order to improve the process of decision making for combustion relevant component setups will be presented. The methodology includes various modules for increasing measurement quality and validity. Modules like stationary point detection to determine steady state engine behavior, signal quality checks to monitor the signal quality of chosen measurement signals and plausibility checks to evaluate physical relations between several measurement signals ensure a high measurement quality over all measurements.
2017-03-28
Technical Paper
2017-01-1003
Ye Liu, Gang Lv, Chenyang Fan, Na Li, Xiaowei Wang
The evolution of surface functional groups (SFGs) and the graphitization degree of soot generated in premixed methane flames are studied and the correlation between them is discussed. Test soot samples were obtained from an optimized thermophoretic sampling system and probe sampling system. The SFGs of soot were determined by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy after removing the soluble impurities from the soot samples, while the graphitization degree of soot was characterized by Raman spectrum and electron energy loss spectroscopy. The results reveal that the concentration of aliphatic C–H groups and C=O groups shows an initial increase and then decrease in the sooting history. The large amount of aliphatic C–H groups and small amount of aromatic C–H groups in the early stage of the soot mass growth process indicate that aliphatic C–H groups make a major contribution to the early stage of soot mass growth.
2017-03-28
Technical Paper
2017-01-0957
Ian Smith, Thomas Briggs, Christopher Sharp, Cynthia Webb
Recent 2010 emissions standards for heavy-duty engines have established a limit of oxides of nitrogen (NOx) emissions of 0.20 g/bhp-hr; however, it is projected that even when the entire on-road fleet of heavy-duty vehicles operating in California is compliant with 2010 emission standards, the National Ambient Air Quality Standards (NAAQS) requirement for ambient particulate matter and Ozone will not be achieved without further reduction in NOx emissions. The California Air Resources Board (ARB) funded a research program to explore the feasibility of achieving 0.02 g/bhp-hr NOx emissions. This paper details the work executed to achieve 0.02 g/bhp-hr NOx emissions over the heavy-duty Federal Test Procedure (FTP) with a heavy-duty natural gas engine equipped with a three-way catalyst. A Cummins ISX-12G natural gas engine was modified and coupled to an advanced catalyst system.
2017-03-28
Technical Paper
2017-01-0968
Anand Srinivasan, Saurabh Joshi, Yadan Tang, Di Wang, Neal Currier, Aleksey Yezerets
Commercial Cu-Zeolite SCR catalyst can store and subsequently release significant amount of H2O. The process is accompanied by large heat effects. It is critical to model this phenomenon to design aftertreatment systems and to provide robust tuning strategies to meet cold start emissions and low temperature operation. The complex reaction mechanism of water adsorption and desorption over a Cu-exchanged SAPO-34 catalyst at low temperature was studied through steady state and transient experiments. Steady state isotherms were generated using a gravimetric method and then utilized to predict water storage interactions with respect to feed concentration and catalyst temperature. Transient temperature programmed desorption (TPD) experiments provided the kinetic information required to develop a global kinetic model from the experimental data. The model captures fundamental characteristics of water adsorption and desorption accompanied by the heat effects.
2017-03-28
Technical Paper
2017-01-0964
Jakob Heide, Mikael Karlsson, Mireia Altimira
Selective Catalytic Reduction (SCR) of NOx through injection of Urea-Water-Solution (UWS) into the hot exhaust gas stream is an effective and extensively used strategy in internal combustion engines. Even though actual SCR systems have 95-96% de-NOx efficiency over test cycles, real driving emissions of NOx are much higher, hence proving that there is room for improvement. The efficiency of the NOx conversion is highly dependent on the size of UWS droplets and their spatial distribution. These factors are, in turn, mainly determined by the spray characteristics and its interaction with the exhaust gas flow. The main purpose of this study is to numerically investigate the sensitivity to the modelling framework of the evaporation and mixing of the spray upstream of the catalyst. The dynamics of discrete droplets is handled through the Lagrangian Particle Tracking framework, with models that account for droplet breakup and coalescence, turbulence effects, and water evaporation.
2017-03-28
Technical Paper
2017-01-0928
Osama M. Ibrahim
Diesel oxidation catalysts based on Palladium-Tungsten (Pd-W) have been developed. The catalysts are supported by aluminum-yttrium oxides (Al2O3-Y2O3) nano-washcoat on sintered metal fibers. Surface chemical analysis is performed using a Field Emission Scanning Electron Microscope (FE-SEM) to quantify the distribution of the Al2O3-Y2O3 nano-washcoats and Pd-W catalysts on the surface of the metal fibers. Carbon monoxide (CO) and nitrogen dioxide (NO2) emissions measurements are conducted to evaluate the performance of Pd-W catalysts using sintered metal fibers coated samples. The results show that the catalysts selectively oxidize CO into CO2 and reduce NO2 into nitric oxide (NO), resulting in over 90% reduction in CO for temperatures higher than 250oC and over 90% reduction in NO2 for temperatures between 180 to 450oC. Scale-up of the exhaust remediation system was then tested on a Cummins 5.9L ISB diesel engine using the FTP transient test cycle and the 8-mode test cycle.
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