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Viewing 61 to 90 of 23233
2016-04-05
Journal Article
2016-01-0947
Junhui Li, Neal Currier, Aleksey Yezerets, Hai-Ying Chen, Howard Hess, Shadab Mulla
Typical Lean NOx Trap (LNT) catalyst composition includes precious metal components (Pt, Pd, and/or Rh), responsible for NO oxidation during lean operation and NOx reduction during rich operation. It was found that redox history of commercial LNT catalyst plays a significant role on deciding its NOx conversion under Lean/Rich cyclic condition. Further test had shown that fully formulated LNT catalyst being pre-reduced had shown much better NO reduction activity during the temperature-programmed reduction (TPRx) of NO than the same LNT catalyst being oxidized. The following study with Rh-only and Pt-only catalyst had demonstrated that Rh plays a key role on the large variation of the NO reduction function due to oxidation state change over LNT catalyst.
2016-04-05
Technical Paper
2016-01-0943
Paul Ragaller, Alexander Sappok, Leslie Bromberg, Natarajan Gunasekaran, Jason Warkins, Ryan Wilhelm
Abstract Efficient aftertreatment management requires accurate sensing of both particulate filter soot and ash levels for optimized feedback control. Currently a combination of pressure drop measurements and predictive models are used to indirectly estimate the loading state of the filter. Accurate determination of filter soot loading levels is challenging under certain operating conditions, particularly following partial regeneration events and at low flow rate (idle) conditions. This work applied radio frequency (RF)-based sensors to provide a direct measure of the particulate filter soot levels in situ. Direct measurements of the filter loading state enable advanced feedback controls to optimize the combined engine and aftertreatment system for improved DPF management. This study instrumented several cordierite and aluminum titanate diesel particulate filters with RF sensors.
2016-04-05
Technical Paper
2016-01-0945
Guanyu Zheng, Suying Zhang, Fengshuang Wang, Zhengrui Liu, Jianzhong Tao
Selective Catalytic Reduction (SCR) based on urea water solution (UWS) has become a promising technology to reduce Nitrogen Oxides (NOx) emissions for mobile applications. However, urea may undergo incomplete evaporations, resulting in formation of solid deposits on the inner surfaces including walls and mixers, limiting the transformation of urea to ammonia and chemical reaction between NOx and ammonia. Numerous design parameters of SCR system affect the formation of urea deposits [1] ; they are: exhaust condition, injector type, injector mounting angle, geometrical configurations of mixer, injection rate and etc. Research has been available in urea deposits, mixers, urea injection rates and others [2,4,5,6]. In this paper, focus is placed on improving mixing structure design from baseline design of EU IV to EU V. On-road tests indicate that deposits are highly likely to occur near locations where spray and exhaust gas interact most.
2016-04-05
Journal Article
2016-01-0942
Nicholas Custer, Carl Justin Kamp, Alexander Sappok, James Pakko, Christine Lambert, Christoph Boerensen, Victor Wong
Abstract The increasing use of gasoline direct injection (GDI) engines coupled with the implementation of new particulate matter (PM) and particle number (PN) emissions regulations requires new emissions control strategies. Gasoline particulate filters (GPFs) present one approach to reduce particle emissions. Although primarily composed of combustible material which may be removed through oxidation, particle also contains incombustible components or ash. Over the service life of the filter the accumulation of ash causes an increase in exhaust backpressure, and limits the useful life of the GPF. This study utilized an accelerated aging system to generate elevated ash levels by injecting lubricant oil with the gasoline fuel into a burner system. GPFs were aged to a series of levels representing filter life up to 150,000 miles (240,000 km). The impact of ash on the filter pressure drop and on its sensitivity to soot accumulation was investigated at specific ash levels.
2016-04-05
Technical Paper
2016-01-0939
Fabian Sonntag, Peter Eilts
Abstract There are numerous methods for accelerated ash loading of particulate traps known from literature. However, it is largely unknown if a combination of these methods is possible and which one generates the most similar ash compared to ash from real particulate filters. Since the influencing variables on the ash formation are not yet fully understood, ashing processes are carried out under carefully controlled laboratory conditions on an engine test bench. The first ashing takes place with low sulfated ash phosphorus and sulfur oil without any methods to increase the quantity of produced ash. The obtained ash is used as a reference and is compared hereinafter with the process examined. Four methods to increase the ash production ratio are investigated. The first one is an increase of the ash content of the lubrication oil through an increase of the additives in the oil. The second one is the additional generation of ash with a burner system where oil is injected into the flame.
2016-04-05
Technical Paper
2016-01-0940
Sam George, Achim Heibel
Abstract Diesel particulate filters (DPF) have become a standard aftertreatment component for a majority of current on-road/non-road diesel engines used in the US and Europe. The upcoming Stage V emissions regulations in Europe will make DPFs a standard component for emissions reductions for non-road engines. The tightening in NOx emissions standard has resulted in the use of selective catalytic reduction (SCR) technology for NOx reduction and as a result the general trend in engine technology as of today is towards a higher engine-out NOx/PM ratio enabling passive regeneration of the DPF. The novel filter concept discussed in this paper is optimized for low pressure drop, high filtration efficiency, and low thermal mass for optimized regeneration and fast heat-up, therefore reducing CO2 implications for the DPF operation.
2016-04-05
Technical Paper
2016-01-0936
Anoop Reghunathan Nair, Brett Schubring, Kiran Premchand, Andrew Brocker, Peter Croswell, Craig DiMaggio, Homayoun Ahari, Jeffrey Wuttke, Michael Zammit, Michael Andrew Smith
New Particulate Matter (PM) and Particulate Number (PN) regulations throughout the world have created a need for aftertreatment solutions that include particulate control as an option to comply with the legislation. However, limitations in other criteria emissions cannot be sacrificed to accomplish the reduction of PM/PN. For this work, three-way washcoat catalyzed wall-flow Gasoline Particulate Filters (GPF) and similarly catalyzed flow-through catalysts of common defined volume were tested. Their catalytic performance was determined by measuring NOx, CO and HC conversion efficiencies and CO2 levels over the U.S. Federal Test Procedure 75 (FTP-75) and US06 Supplemental Federal Test Procedure (US06) cycles. Analysis of the impact on CO2 emissions was also evaluated in relation to backpressure from 1-D modeling analysis. All exhaust systems used the same loading and ratio of Platinum Group Metals (PGM), but employed different cell structures in their substrates.
2016-04-05
Journal Article
2016-01-0934
Vitaly Y. Prikhodko, James E. Parks, Josh A. Pihl, Todd J. Toops
Abstract Lean gasoline engines offer greater fuel economy than the common stoichiometric gasoline engine, but the current three way catalyst (TWC) on stoichiometric engines is unable to control nitrogen oxide (NOX) emissions in oxidizing exhaust. For these lean gasoline engines, lean NOX emission control is required to meet existing Tier 2 and upcoming Tier 3 emission regulations set by the U.S. Environmental Protection Agency (EPA). While urea-based selective catalytic reduction (SCR) has proven effective in controlling NOX from diesel engines, the urea storage and delivery components can add significant size and cost. As such, onboard NH3 production via a passive SCR approach is of interest. In a passive SCR system, NH3 is generated over a close-coupled TWC during periodic slightly rich engine operation and subsequently stored on an underfloor SCR catalyst. Upon switching to lean operation, NOX passes through the TWC and is reduced by the stored NH3 on the SCR catalyst.
2016-04-05
Technical Paper
2016-01-0937
James E. Parks, John M. E. Storey, Vitaly Y. Prikhodko, Melanie M. Debusk, Samuel A. Lewis
Abstract New regulations requiring increases in vehicle fuel economy are challenging automotive manufacturers to identify fuel-efficient engines for future vehicles. Lean gasoline direct injection (GDI) engines offer significant increases in fuel efficiency over the more common stoichiometric GDI engines already in the marketplace. However, particulate matter (PM) emissions from lean GDI engines, particularly during stratified combustion modes, are problematic for lean GDI technology to meet U.S. Environmental Protection Agency Tier 3 and other future emission regulations. As such, the control of lean GDI PM with wall-flow filters, referred to as gasoline particulate filter (GPF) technology, is of interest. Since lean GDI PM chemistry and morphology differ from diesel PM (where more filtration experience exists), the functionality of GPFs needs to be studied to determine the operating conditions suitable for efficient PM removal.
2016-04-05
Technical Paper
2016-01-0935
Gerben Doornbos, Stina Hemdal, Daniel Dahl, Ingemar Denbratt
Passive selective catalyst reduction (SCR) systems can be used as aftertreatment systems for lean burn spark ignition (SI)-engines. Their operation is based on the interaction between the engine, an ammonia formation catalyst (AFC), and an SCR catalyst. Under rich conditions the AFC forms ammonia, which is stored in the SCR catalyst. Under lean conditions, the SCR catalyst reduces the engine out NOx using the stored NH3. This study compared the ammonia production and response times of a standard three way catalyst (TWC) and a Pd/Al2O3 catalyst under realistic engine operating conditions. In addition, the relationships between selected engine operating parameters and ammonia formation over a TWC were investigated, considering the influence of both the chosen load point and the engine settings.
2016-04-05
Technical Paper
2016-01-0932
Masanori Hashimoto, Yoshiyuki Nakanishi, Hiroshi Koyama, Syouji Inose, Hiroki Takeori, Takayuki Watanabe, Takeshi Narishige, Tatsuya Okayama, Yukio Suehiro
Abstract Engine technologies using efficient combustion and down-sizing turbo have become important in order to reduce automotive CO2 emissions. However, the exhaust gas temperature also becomes lower by these technologies. As a result, the catalyst performance becomes lower. Therefore it is necessary to develop low temperature active catalysts to reduce emissions. This research was focused on Pd/CeO2, and it’s able to oxidize CO at low temperatures. In order to increase the catalyst activity, the addition of some elements to the CeO2 was studied. Zn addition was found to have an advantage to reduce the CO light off temperature by 60 °C. Then, we tried to clarify the cause of improvement. As a result, it made clear that the Zn addition promotes the active oxygen release from the CeO2 surface. However, repeated engine exhaust gas tests indicated a decline in purification performance.
2016-04-05
Technical Paper
2016-01-0933
Steve Golden, Zahra Nazarpoor, Maxime Launois, Ru-Fen Liu, Pardha Maram
Abstract In the context of evolving market conditions, the three-way catalyst (TWC) design is entering an exciting new phase. It remains the main emission control strategy for gasoline powered vehicles; in the meantime a rapid period of evolving engine developments, the constrained tailpipe regulations and the material supply issues present a unique challenge to the catalyst developers. A key approach here is to achieve highly beneficial emission performance based on the ultra-low PGM levels. In this regard, we mainly focus on the materials design and have developed the advanced spinel oxides for zero precious metals (ZPGM) and synergized precious metals (SPGM) TWCs. These advanced spinel materials showed improved thermal stability compared to that of PGM based standard materials. Fundamental studies on the microstructure of spinel oxide with newly developed composition confirm the aging stability.
2016-04-05
Technical Paper
2016-01-0930
Yasunari Hanaki, Misaki Fujimoto, Junji Itou
Abstract This paper describes a new catalyst powder has been developed that provides cleaner exhaust emissions and reduces the consumption of precious metals. In recent years, precious metal usage has been increasing due to the tightening of emission regulations and the increase in automobile production worldwide. Minimizing the use of precious metals in exhaust catalysts is crucial not only for reducing the cost of vehicles but also for effective utilization of scarce resources. Iron is one of the alternative material candidates for precious metals. It was found that the Iron catalyst was activated by iron becoming the low oxidation state while iron oxide and cerium oxide synchronized in a nanostructure interface. A catalyst with improved iron support technology that enables better contact between highly dispersed particles of iron and ceria was found to exhibit higher exhaust gas cleansing performance than precious metal catalysts even after aging.
2016-04-05
Technical Paper
2016-01-0931
Akifumi Kawakami, Yuki Fukumi, Masaaki Ito, Shingo Sokawa, Satoshi Sakashita, Mychal Taylor, Mitsuhiro Ito, Masataka Yamashita, Hirofumi Sakamoto, Hiroshi Kurachi
Abstract Honeycomb substrates are widely used to reduce harmful emissions from gasoline engines and are exposed to numerous thermal shocks during their lifetime making thermal shock resistance one of the key factors in designing honeycomb substrates. More stringent emission regulations will require the honeycomb substrates to be lighter in weight to improve light-off performance and to have better thermal shock resistance than conventional honeycomb substrates to handle higher expected temperature gradients. Thermal shock resistance is generally evaluated on a substrate by evaluating the thermal strain caused by temperature gradients inside the substrate during durability testing [1,2]. During the test, a heated substrate is cooled at a surface face to generate temperature gradients while the temperature inside the honeycomb substrate is monitored by multiple thermocouples.
2016-04-05
Technical Paper
2016-01-0928
Sujay Bagi, Nishant Singh, Rob Andrew
Abstract Ash accumulation in the DPF over life results in reduced soot storage capacity, lower catalytic activity and may even alter substrate properties and lead to higher back-pressure; hence ash-cleaning of the DPF is required periodically to extend the life of the DPF and restore its catalytic performance. Several ash cleaning technologies are available which utilize pneumatic, hydraulic and wet-chemical cleaning techniques or their combinations. A batch of DPFs with various ash accumulation levels were recovered from customer field units. X-ray CT imaging was performed to understand the ash distribution in the DPF channels. Field returned DPFs were tested on Engine Dynamometer to determine the impact on overall system performance loss from fresh state. The DPFs were then cleaned using various cleaning techniques; X-ray imaging and dynamometer testing was repeated to evaluate the performance recovery.
2016-04-05
Technical Paper
2016-01-0926
Teuvo Maunula, Thomas Wolff, Auli Savimäki
The tightening pollutant emission limits require the use of active aftertreatment methods for NOx and particulate matter (PM). Diesel particulate filter (DPF) is a part of commercial aftertreatment system (ATS). PM accumulated in DPF is continuously passively or periodically actively regenerated with the assistance of efficient diesel oxidation catalysts (DOC) having a high efficiency and durability in hydrocarbon (HC), NO and CO oxidation reactions. A high HC concentration during fuel feeding in active regeneration is demanding for DOC. The deactivation in air, hydrothermal, sulfation and active regeneration conditions were evaluated with platinum (Pt-) and platinum-palladium (PtPd)-DOCs by laboratory simulations using the ageing temperature and time as primary variables. The oxidizing conditions with a high oxygen concentration without HCs were deactivating DOCs clearly more than active regeneration conditions with a low oxygen and high HC concentration at 700-800°C.
2016-04-05
Journal Article
2016-01-0925
Angus Craig, Jason Warkins, Krishna Aravelli, David Moser, Lucy Yang, Douglas Ball, Tinghong Tao, Deven Ross
Abstract A production calibrated GTDI 1.6L Ford Fusion was used to demonstrate low HC, CO, NOx, PM (particulate mass), and PN (particulate number) emissions using advanced catalyst technologies with newly developed high porosity substrates and coated GPFs (gasoline particulate filters). The exhaust system consisted of 1.2 liters of TWC (three way catalyst) in the close-coupled position, and 1.6L of coated GPF in the underfloor position. The catalysts were engine-aged on a dynamometer to simulate 150K miles of road aging. Results indicate that ULEV70 emissions can be achieved at ∼$40 of PGM, while also demonstrating PM tailpipe performance far below the proposed California Air Resources Board (CARB) LEV III limit of 1 mg/mi. Along with PM and PN analysis, exhaust system backpressure is also presented with various GPF designs.
2016-04-05
Technical Paper
2016-01-0924
Shun Nakagawa, Ichiro Tsumagari, Shinya Sato, Koichi Machida
Abstract The conventional NOx after-treatment system could not perform sufficient NOx removal since exhaust gas temperature falls down by low-fuel-consumption and waste heat recovery of a diesel engine. In order to realize a new after-treatment system with high NOx conversion rate at a low catalyst temperature, studies on adopting an ozone generator (NO oxidization promotion) and a urea reformer (ammonia addition) into the Urea SCR (Selective Catalytic Reduction) system have been conducted.
2016-04-05
Technical Paper
2016-01-0923
Martin Schneider, Bernd Danckert
Abstract Since the new “Regulations for the Prevention of Air Pollution from Ships” of the International Maritime Organization (IMO; MARPOL Annex VI Tier III) became effective, new technologies in marine applications are needed to fulfill the exhaust-gas limits. The reduction rate of the permissible emissions in the emission control areas (ECA) is about 75 % from Tier II to Tier III. To meet these limits, it is necessary to take additional measures, such as installing a Selective Catalytic Reduction (SCR) system. Because harbors are specifically in focus regarding the air quality, a hybrid propulsion system (Diesel-electric) and Exhaust Aftertreatment (EAT) to reduce the emissions and the lifecycle costs by reducing the fuel consumption were planned back in 2012. With the goal in mind of decreasing all relevant emissions, the described compact EAT consists of a Diesel Oxidation Catalyst (DOC), a Particulate Matter (PM) removal and a SCR-catalyst.
2016-04-05
Journal Article
2016-01-0921
Ashok Kumar, Kristopher Ingram, Deepesh Goyal, Krishna Kamasamudram
Abstract Exposure of hydrocarbons (HCs) and particulate matter (PM) under certain real-world operating conditions leads to carbonaceous deposit formation on V-SCR catalysts and causes reversible degradation of its NOx conversion. In addition, uncontrolled oxidation of such carbonaceous deposits can also cause the exotherm that can irreversibly degrade V-SCR catalyst performance. Therefore carbonaceous deposit mitigation strategies, based on their characterization, are needed to minimize their impact on performance. The nature and the amount of the deposits, formed upon exposure to real-world conditions, were primarily carried out by the controlled oxidation of the deposits to classify these carbonaceous deposits into three major classes of species: i) HCs, ii) coke, and iii) soot. The reversible NOx conversion degradation can be largely correlated to coke, a major constituent of the deposit, and to soot which causes face-plugging that leads to decreased catalyst accessibility.
2016-04-05
Technical Paper
2016-01-0920
Bradford A. Bruno, Ann M. Anderson, Mary Carroll, Thomas Swanton, Paul Brockmann, Timothy Palace, Isaac A. Ramphal
Abstract Aerogels are nanoporous structures with physical characteristics that make them promising for use in automotive exhaust catalysis systems: highly porous with low densities (<0.1 g/mL) and high surface area per unit mass (>300 m2/g) - features that provide favorable characteristics for catalysis of gaseous pollutants. Ceramic aerogels are also highly thermally insulating (∼0.015 W/mK) and able to withstand high temperatures. Aerogels can be made of a wide variety of ceramics (e.g. alumina, silica, titania) with other catalytically active metals (e.g. copper, cobalt, nickel) incorporated into their structures. This paper provides a brief overview of the rapid supercritical extraction (RSCE) method employed in this work for aerogel preparation, describes in detail the benchtop scale testbed and methods used to assess the catalytic activity of RSCE fabricated aerogels, and presents data on the catalytic ability of some promising aerogel chemistries.
2016-04-05
Technical Paper
2016-01-0918
Alexander Sappok, Paul Ragaller, Leslie Bromberg, Vitaly Prikhodko, John Storey, James Parks
Abstract Radio frequency (RF)-based sensors provide a direct measure of the particulate filter loading state. In contrast to particulate matter (PM) sensors, which monitor the concentration of PM in the exhaust gas stream for on-board diagnostics purposes, RF sensors have historically been applied to monitor and control the particulate filter regeneration process. This work developed an RF-based particulate filter control system utilizing both conventional and fast response RF sensors, and evaluated the feasibility of applying fast-response RF sensors to provide a real-time measurement of engine-out PM emissions. Testing with a light-duty diesel engine equipped with fast response RF sensors investigated the potential to utilize the particulate filter itself as an engine-out soot sensor.
2016-04-05
Technical Paper
2016-01-0916
Nebojsa Milovanovic, Shant Hamalian
Abstract The future emission legislations for diesel passenger cars are likely to include more dynamic test cycles than we have today, such as the World harmonized Light duty Testing Cycle (WLTC) and Real Drive Emissions (RDE) in the EU and very challenging SULEV legislations in the USA. In order to meet these emission legislations and challenging CO2 targets, more complex Exhaust Gas After Treatment Systems - EGATS and corresponding calibration strategies are needed. The calibration strategies have to provide the best possible fuel consumption and NOx emissions across the entire engine map for all tested cycles. The aim of this paper is to evaluate the effect of several EGATS configurations and calibrations on tailpipe NOx and CO2 emissions of a D segment vehicle. The experimental results and potential of various EGATS configurations and calibrations for the optimisation of fuel consumption and NOx emissions are presented and discussed.
2016-04-05
Journal Article
2016-01-0914
Yaritza M. López - De Jesús, Peter I. Chigada, Timothy C. Watling, Kaneshalingam Arulraj, Anna Thorén, Neil Greenham, Penelope Markatou
Abstract Future heavy-duty diesel (HDD) engines are designed to have higher engine out NOx, for improved fuel economy, while reduction of the emission control technology footprint is also desired. Consequently, higher NOx reduction across compact emission control systems is required. Selective catalytic reduction (SCR) catalyst coating combined with a wall flow particulate filter (SCRF®1) is a technology that enables abatement of NOx emissions in addition to oxidation of soot from diesel engine exhausts. Vanadia based-SCR is well known for NOx reduction and is active for hydrocarbon (HC) and particulate matter (PM) oxidation. This dual functionality (oxidation and reduction reactions) of the V.SCR catalysts plus the filtration achieved by the filter substrate can help certain diesel engine applications achieve the legislative limits with a reduced packaging volume.
2016-04-05
Technical Paper
2016-01-0912
MohanKumar Subramaniam, Senthilkumar Pachamuthu, Jayanth Arulanandan, Jenoris Muthiya
Abstract Exhaust after treatment devices in diesel engines play a crucial role in control of harmful emissions. The noxious emission released from diesel engines causes a variety of problems to both human beings and the environment. The currently used devices are implemented with new catalyst technologies like DOC, SCR and catalytic converter are all designed to meet stringent emission regulations. Although these devices have considerable conversion efficiency, they are not without drawbacks. The catalysts used in these devices are rarely available and are also very expensive. Diesel Particulate Filter (DPF) is the device currently employed to collect particulate matter. It also has drawbacks like high back pressure, thermal durability restrictions, regeneration issues and poor collection of smaller size particles. In the case of biodiesel these fine sized particles are emitted in larger quantity.
2016-04-05
Technical Paper
2016-01-1015
Somendra Pratap Singh, Shikhar Asthana, Naveen Kumar
Abstract Recent scenario of fossil fuel depletion as well as rising emission levels has witnessed an ever aggravating trend for decades. The solution to the problems has been addressed by investments and research in the field of fuels; such as the use of cleaner fuels involving biodiesel, alcohol blends, hydrogen and electric drivelines, as well as improvement in traditional technologies such as variable geometry systems, VVT load control strategies etc. The developments have highlighted the enormous potential present in such systems in terms of maximizing engine efficiency and emission reductions. The present paper aims at designing and implementing an intake runner system for a CI engine capable of providing flexibility with variations in operating conditions. Primarily, the design aims at altering the air flow phenomenon within the primary intake of the engine by inducing swirl in the runner through a secondary runner.
2016-04-05
Technical Paper
2016-01-1016
Yolanda Bravo, Carmen Larrosa, Jose Lujan, Héctor Climent, Manuel Rivas
Abstract Spark ignition (SI) engines are increasing their popularity worldwide since compression ignition (CI) engines have been struggling to comply with new pollutant emission regulations. At the moment, downsizing is the main focus of research on SI engines, decreasing their displacement and using a turbocharging system to compensate this loss in engine size. Exhaust gas recirculation is becoming a popular strategy to address two main issues that arise in heavily downsized turbocharged engines at full load operation: knocking at low engines speeds and fuel enrichment at high engine speeds to protect the turbine. In this research work, a fuel consumption optimization for different operating conditions was performed to operate with a cooled EGR loop, with gasoline and E85. Thus, the benefits of exhaust gas recirculation are proven for a SI gasoline turbocharged direct injection engine.
2016-04-05
Technical Paper
2016-01-1005
Yuanzhou Xi, Nathan Ottinger, Z. Gerald Liu
Abstract Regulations on methane emissions from lean-burn natural gas (NG) and lean-burn dual fuel (natural gas and diesel) engines are becoming more stringent due to methane’s strong greenhouse effect. Palladium-based oxidation catalysts are typically used for methane reduction due to their relative high reactivity under lean conditions. However, the catalytic activity of these catalysts is inhibited by the water vapor in exhaust and decreases over time from exposure to trace amounts of sulfur. The reduction of deactivated catalysts in a net rich environment is known to be able to regenerate the catalyst. In this work, a multicycle methane light-off & extinction test protocol was first developed to probe the catalyst reactivity and stability under simulated exhaust conditions. Then, the effect of two different regeneration gas compositions, denoted as regen-A and regen-B, was evaluated on a degreened catalyst and a catalyst previously tested on a natural gas engine.
2016-04-05
Technical Paper
2016-01-1006
Cary Henry, Svitlana Kroll, Vinay Premnath, Ian Smith, Peter Morgan, Imad Khalek
Abstract In this study, the criteria pollutant emissions from a light duty vehicle equipped with Dedicated EGR® technology were compared with emissions from an identical production GDI vehicle without externally cooled EGR. In addition to the comparison of criteria pollutant mass emissions, an analysis of the gaseous and particulate chemistry was conducted to understand how the change in combustion system affects the optimal aftertreatment control system. Hydrocarbon emissions from the vehicle were analyzed usin g a variety of methods to quantify over 200 compounds ranging in HC chain length from C1 to C12. The particulate emissions were also characterized to quantify particulate mass and number. Gaseous and particulate emissions were sampled and analyzed from both vehicles operating on the FTP-75, HWFET, US06, and WLTP drive cycles at the engine outlet location.
2016-04-05
Technical Paper
2016-01-1003
Fabian Fricke, Om Parkash Bhardwaj, Bastian Holderbaum, Terrence Scofield, Elmar Grußmann, Marco Kollmeier
Abstract Improvements in the efficiency of internal combustion engines has led to a reduction in exhaust gas temperatures. The simultaneous tightening of exhaust emission limits requires ever more complex emission control methods, including aftertreatment whose efficiency is crucially dependent upon the exhaust gas temperature. Double-walled (also called air-gap) exhaust manifold and turbine housing modules made from sheet metal have been used in gasoline engines since 2009. They offer the potential in modern Diesel engines to reduce both the emissions of pollutants and fuel consumption. They also offer advantages in terms of component weight and surface temperatures in comparison to cast iron components. A detailed analysis was conducted to investigate the potential advantages of insulated exhaust systems for modern diesel engines equipped with DOC and SCR coated DPF (SDPF).
Viewing 61 to 90 of 23233

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