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Viewing 31 to 60 of 22741
2015-04-14
Technical Paper
2015-01-1061
Piotr Bielaczyc, Andrzej Szczotka, Joseph Woodburn
Technology for light-duty CNG (Compressed Natural Gas) vehicles is well established, and CNG vehicles have performance comparable to their petrol-fuelled equivalents. CNG is commonly used in spark ignition (SI) engines because their powertrains are relatively easy to convert from liquid to gaseous fuels. In addition, the importance of natural gas (NG) will increase significantly as fuel for transportation. Apart from its massive availability at attractive current market prices, its particular advantages in terms of CO2 (carbon dioxide) and exhaust emissions have led to the increased interest in NG as a fuel source. The aim of this paper was to explore the influence of CNG fuel on emissions in the context of the new Euro 6 emissions requirements and to compare exhaust emissions of the vehicles fuelled with CNG and with petrol.
2015-04-14
Technical Paper
2015-01-1298
Sangram Jadhav
In this study, the optimization of experimental parameters, such as alcohol to oil molar ratio (1:08, 1:12 and 1:16), homogeneous catalyst loading (0.5, 1 and 1.5 wt %), homogeneous catalyst types (NaOH, KOH and NaOCH3) and reaction temperature (59, 64 and 69°C) on the transesterification for the production of Mangifera oil methyl ester (Biodiesel) was performed. Homogenous alkali catalyzed method has been used for biodiesel production by using homogenous catalyst such as NaOH, KOH and NaOCH3. The taguchi method was adopted as the experimental conditions from a limited number of experiments (Columns of L9 (3**4) Array) and contribution of each signal to noise factor calculated by ANOVA. The optimum experimental condition obtained from this study are; 1:16 methanol to oil molar ratio, KOH as the catalyst type, at a loading 1.5 wt% and a reaction temperature of 64°C played the most important role in the yield of Mangifera methyl ester.
2015-04-14
Technical Paper
2015-01-0986
Dieter Rauch, David Kubinski, Giovanni Cavataio, Devesh Upadhyay, Ralf Moos
For lowering the emissions of nitrogen oxides (NOx) from learn burn diesel engines, the selective catalytic reduction (SCR) with ammonia (NH3) as reducing agent has become serial standard as exhaust gas aftertreatment system. Zeolites are in use as catalyst material as they show a high SCR performance over a wide temperature window. A crucial step in the SCR reaction mechanism over zeolites is an initial adsorption of NH3 on the catalyst surface. Only then, NOX can be converted to harmless N2 and H2O by the zeolite catalyst. In this study, a Chabazite SSZ-13 with and without copper exchange was investigated. Due to NH3 adsorption, the proton conductivity of the zeolite increases distinctly. By monitoring these changes in the material properties of the catalyst material, the NH3 loading can be in operando determined. In this work, a radio frequency technique, based on the cavity perturbation method, was applied to measure these effects.
2015-04-14
Technical Paper
2015-01-0989
Steve Schiller, Mark Brandl, Bruce Hoppenstedt, Korneel De Rudder
Diesel engine NOx emissions requirements have become increasingly stringent. Engine manufacturers have shown through the use of EGR and SCR technology that these requirements can be met. However, the demands for improved fuel efficiency, lower overall cost, and potential legislation to reduce NOx levels further increase the demand for higher DEF dosing rates. To meet this demand, a new DEF mixing technology has been developed. This paper describes the development of a compact, in-pipe mixer which utilizes an optimized wire mesh along with swirling flow to permit very high dosing rates without deposit formation while maintaining excellent mixing for high NOx reduction. Utilization of this technology makes it possible to reduce regeneration frequency, reduce the size of the SCR system, possibly eliminate the EGR system, and improve fuel efficiency through combustion enhancements.
2015-04-14
Technical Paper
2015-01-1038
Jinbiao Ning, Fengjun Yan
Using urea-based Selected Catalytic Reduction (SCR) systems is an effective way in diesel engine after-treatment systems to meet increasingly stringent emission regulations. The amount of urea injection is critical to achieve high NOx reduction efficiency and low ammonia slip and overdosing or under-dosing of urea injection need to be avoided. One of the difficulties in urea injection amount control lies in the accurate measurement/estimation of the urea injection mass. To effectively address this issue, this paper proposed two methods for under-dosing or overdosing detection and correction. The first method is based on urea pump model. Through frequency analysis, the relation between the urea pump speed and power spectrum characteristics of the line pressure by using FFT method was revealed. A frequency extraction method is adopted to calculate the pump speed without speed sensors. Second method is based on the control of the PWM duty cycles for the Motor and battery voltage.
2015-04-14
Technical Paper
2015-01-1065
Piotr Bielaczyc, Joseph Woodburn, Andrzej Szczotka
Increasing concern over anthropogenic greenhouse gas (GHG) emissions and general air quality and sustainability concerns has made the issue of fuel consumption by passenger cars a topic of great technical and political interest, at an international level. Carbon dioxide is the GHG of most importance regarding passenger cars running on conventional carbon-based fuels, with fleet average limits for CO2 emissions now in force in the European Union. In the USA, CO2 emissions are effectively subject to fleet average limits, although the metric employed is fuel economy – CO2 being the strongest controlling factor. In fact, regardless of the metric employed, 3 out of every 4 vehicles sold globally in 2012 were subject to some kind of energy efficiency regulation. In this context, accurate, repeatable measurement of CO2 emissions from passenger cars is vital for a variety of reasons, and these measurements are arguably more critical than in the past.
2015-04-14
Technical Paper
2015-01-1037
Colin L. Weeks, Dan R. Ibeling, Sonia Han, Lindsey Ludwig, Ponnaiyan Ayyappan
Colin L. Weeks*, Dan Ibeling, Sonia Han, Lindsey Ludwig Department of Chemistry and Biochemistry, University of Northern Iowa, Cedar Falls, IA, 50614 Ayyappan Ponnaiyan* John Deere Power Systems, Cedar Falls, IA 50613 *Addresses for Correspondence: Dr Colin L. Weeks Department of Chemistry and Biochemistry University of Northern Iowa Cedar Falls, IA 50614-0423 Phone: (319) 273-2805 Email: colin.weeks@uni.edu Dr. Ayyappan Ponnaiyan John Deere Power Systems 6725 Cedar Heights Drive Cedar Falls, IA, 50613 Phone: (319) 292-8653 Email: AyyappanPonnaiyan@johndeere.com   Abstract An aqueous urea solution is used as the source of ammonia for selective catalytic reduction (SCR) of NOx to reduce the emissions of NOx in the exhaust of diesel vehicles. However, the decomposition of urea into ammonia is not always complete, resulting in solid urea deposit formation in the decomposition tube or on the SCR catalyst.
2015-04-14
Technical Paper
2015-01-0995
Aditya Palsule
A proposal of developing split Catcon-Muffler was made to be used in front engine low floor bus from perspective of cost saving, modularity and reduction in complexity. This system is developed as an alternate to an existing solution of integrated Catcon and muffler. The paper describes the development of a split Catcon and muffler exhaust system for a low floor front engine bus, so as to meet cost and time considerations. The development had to achieve a feasible muffler + catalytic converter solution, which could be installed within the packaging volume of the existing configuration, while meeting the regulatory requirements for Pass by noise, and at the same time conforming to backpressure limits set for optimum engine performance. Multiple design – prototypes – test iterations were carried out to meet the Pass by noise and back pressure target of engine. The final solution was developed which achieved both the requirements within the specified space constraints.
2015-04-14
Technical Paper
2015-01-1053
Jonathan E. Etheridge, Timothy C. Watling, Andrew J. Izzard, Michael A. J. Paterson
The Diesel Oxidation Catalyst (DOC) is an important technology for the removal of CO and hydrocarbons from the exhaust of diesel engines, as well as for generating exotherms for active regeneration and for producing NO2 used by downstream components. Generally, DOCs are bimetallic Pt-Pd based catalysts. This paper presents a two-part study on the effect of Pt:Pd ratio (at constant total Pt+Pd loading by weight) on the catalytic performance of a DOC, covering ratios across the full range from 100% Pd to 100% Pt. The first part of this paper presents a reactor study on the effect of Pt:Pd ratio on the catalytic activity of key reactions occurring individually over the DOC, viz. the oxidation of CO, C3H6, n-C10H22, CH4 and NO.
2015-04-14
Technical Paper
2015-01-1069
Philipp Baumann, Matthias Schroeder, Harald Kurz, Thomas Maier, Wolfgang Thiel, Udo Strehl
The continuous trend towards more resource efficient and less pollutant emitting individual traffic is reflected in a wide range of modern propulsion concepts including Plug-In Hybrid Electric Vehicles (PHEVs). This variety of increasingly complex powertrains is associated with a number of challenges to measure exhaust gas emissions. Although the conventional constant volume sampler (CVS) and exhaust gas measurement systems being a high precision emission measurement concept there are still questions to be answered: • Which measurement uncertainties have to be considered, such as mass transport of exhaust emissions from the transfer tube into the dilution tunnel during engine-off phases? • Is the tested PHEV influenced by the measurement system, e.g. catalyst cooling? • Can different types of PHEV be adequately tested with the existing exhaust emission measurement system and test procedure regarding the European emission legislation?
2015-04-14
Technical Paper
2015-01-0978
Lori Lemazurier, Neeraj Shidore, Namdoo Kim, Ayman Moawad, Aymeric Rousseau, Phillip Bonkoski, Jeremy Delhom
Near term advances in SI engine technology (VVL, GDI, cylinder deactivation, turbo downsizing) for passenger vehicles hold promise of significant fuel savings in the vehicles of the immediate future. Similarly, trends in transmissions indicate higher gear numbers (8 speed, 9 speed), higher spans and a focus on down-speeding to improve engine efficiency. Dual clutch transmissions exhibit higher efficiency than the traditional automatics, and are being introduced in the light duty vehicle segment worldwide. Another development with low investment and immediate benefits has been the adaptation of start-stop (idle engine stop) technology in vehicles today. This paper evaluates the impact of each of these technologies (engines, transmissions, start stop) on the fuel economy and performance of a compact car in the year 2020 through the use of vehicle system simulation.
2015-04-14
Technical Paper
2015-01-1085
Marc C. Besch, Joshua Israel, Hemanth Kappanna, Arvind Thiruvengadam, Daniel Carder
Natural gas (NG) has immerged as a promising energy source to power the transportation sector over the next decades due to its abundant availability and comparably less production intensive process from well-to-tank than associated with conventional liquid hydrocarbon fuels. Furthermore, natural gas’s clean-burning properties and reduced carbon footprint make it a fuel of choice to comply with upcoming stricter emissions and greenhouse gas (GHG) regulations and aid in attaining national ambient air quality standards. Especially Diesel/NG dual-fuel operation has gained increased interest as it allows to combine both improved combustion efficiencies, inherent to the diesel-cycle, with the low carbon properties of NG.
2015-04-14
Technical Paper
2015-01-1079
Jan Czerwinski, Pierre Comte, Adrian Wichser, Andreas Mayer, Jacques Lemaire
The invisible nanoparticles (NP)*) from combustion processes penetrate easily into the human body through the respiratory and olfactory ways and cary numerous harmful health effects potentials. NP count concentrations are limited in EU for Diesel passenger cars since 2013 and for gasoline cars with direct injection (GDI) since 2014. The limit for GDI was temporary extended to 6 x 1012 #/km. Nuclei of metals as well as organics are suspected to significantly contribute especially to the ultrafine particle size fractions, and thus to the particle number concentration. In the project GasOMeP (Gasoline Organic & Metal Particulates) metal-nanoparticles (including sub 20nm) from gasoline cars are investigated for different engine technologies. In the present paper some results of investigations of nanoparticles from four gasoline cars - an older one with MPI and three never with DI - are represented. The measurements were performed at vehicle tailpipe and in CVS-tunnel.
2015-04-14
Technical Paper
2015-01-1048
Per Nicolin, Dominik Rose, Florian Kunath, Thorsten Boger
The share of gasoline engines based on direct injection (DI) technology is rapidly growing, to a large extend driven by their improved efficiency and potential to lower CO2 emissions. One downside of these advanced engines are their significantly higher particulate emissions compared to engines based on port fuel injection technologies. Gasoline particulate filters (GPF) are one potential technology path to address the EU6 particulate number regulation for vehicles powered by gasoline DI engines. For the robust design and operation of GPFs it is essential to understand the mechanisms of soot accumulation and oxidation under typical operating conditions. In this paper we will first discuss the use of detailed numerical simulation to describe the soot oxidation in particulate filters under typical gasoline engine operating conditions. Laboratory experiments are used to establish a robust set of soot oxidation kinetics.
2015-04-14
Technical Paper
2015-01-1004
Joseph R. Theis, Jeong Kim, Giovanni Cavataio
A laboratory study was performed to assess the potential capability of passive TWC+SCR systems to satisfy the Tier 2 Bin 2 emission regulations on lean-burn gasoline applications. After accounting for cold-start emissions, stoichiometric emissions, and engineering tolerances, target levels for HC, CO, and NOx during lean/rich cycling were established. 30 s lean/10 s rich tests were performed on a reduced-OSC Pd/Rh TWC operating at 550oC and different volumes of a Cu/zeolite SCR catalyst operating at 330 C, where the NO concentration was held at 220 ppm during the lean periods and varied from 500 to 2000 ppm during the rich periods. The NOx slip target was satisfied with the equivalent of 3.3L of SCR volume and 1500 ppm NO rich. Reducing the OSC in the TWC would increase its NH3 yield, but some OSC is needed for stoichiometric NOx lightoff, warmed-up 3-way activity, steam reforming of the HC during the rich purge periods, and diagnostic capabilities.
2015-04-14
Technical Paper
2015-01-1005
Masahide Miura, Yuki Aoki, Nobusuke Kabashima, Takahiko Fujiwara, Toshitaka Tanabe, Akira Morikawa, Hirotaka Ori, Hiroki Nihashi, Suguru Matsui
In response to the growing awareness for environmental protection, automobile emissions regulations are gradually becoming more stringent all over the world. Moreover, the amount of precious metals used for automobile catalysts is required to decrease in order to lower the consumption of natural resources. As a consequence, further improvements to catalysts which contribute to a decrease in the amount of precious metals used while satisfying emission regulations are greatly needed. In this report, with the application of nanoparticle rhodium (Rh) clusters with controlled optimized particle sizes along with a high thermal stabilized pyrochlore-ceria/zirconia (CZ) catalyst which efficiently controls O2 storage and release, a robust, high performance three-way catalyst enhanced NOx purifying activity has been developed. Moreover, a zone coat strategy has been developed which improves cold start catalytic performance.
2015-04-14
Technical Paper
2015-01-0982
Brandon D. Biller, Philip Wetzel, Pavan Chandras, Sean Keidel
Several diesel passenger car boosting systems were studied to assess their impact on vehicle performance and fuel economy. A baseline 1.5L diesel engine model with a single VGT turbocharger was obtained through Gamma Technologies’ fast running model library. This model was modified to explore multiple two stage boosting systems to represent the anticipated architecture of future engines. A series sequential turbocharged configuration and a series turbocharger-supercharger configuration were evaluated. The torque curves were increased from that of the original engine model to take advantage of the increased performance offered by two stage boosting. The peak cylinder pressure for all models was limited to 180 bar. Drive cycle analysis over the WLTP was performed using these engine architectures, while assessing the sensitivity to various system parameters. These parameters include: vehicle weight and aerodynamic drag, EGR target maps, level of downspeeding, and turbocharger inertia.
2015-04-14
Technical Paper
2015-01-1029
Michael Smith, Homayoun Ahari, Michael Zammit, Jasonv Jacques, Thomas Pauly
Significant reduction in Nitrogen Oxide (NOx) emissions will be required to meet LEV III/Tier III Emissions Standards for Light Duty Diesel passenger vehicles (LDD). As such, Original Equipment Manufacturers (OEMs) are exploring all possible after treatment options to find the best balance between performance, robustness and cost. The primary technology adopted by OEMs in North America to achieve low NOx levels is Selective Catalytic Reduction (SCR) catalyst. The critical parameters needed for SCR to work properly are: an appropriate reductant such as ammonia (NH3) provided as urea, optimum operating temperatures, and optimum Nitrogen Dioxide (NO2) to NOx ratios (NO2/NOx). The NO2/NOx ratio is most influenced by Precious Group Metals (PGM) containing catalysts upstream of the SCR catalyst. Different versions of zeolite based SCR technologies are available on the market today and these vary in their active metal type (iron, copper, etc), and/or zeolite type.
2015-04-14
Technical Paper
2015-01-1021
Brad Adelman, Navtej Singh, Paul Charintranond, Greg Griffin, Shyam Santhanam, Ed Derybowski, Adam Lack
Current legislative trends regarding diesel emissions are striving to achieve two seemingly competing goals: simultaneously lowering NOx and Green House Gas (GHG) emissions. These two goals are considered at odds since lower GHG emissions (e.g. CO2) is achieved via high combustion efficiency resulting in higher engine out NOx emissions and lower exhaust gas temperatures. Conversely, NOx reduction technologies such as SCR require temperatures above 200°C for dosing the reductant (DEF). Dosing DEF requires injection pressures around 5 bar. This is required to ensure proper penetration into the exhaust stream as well as generate the appropriate spray pattern and droplet sizes. Dosing DEF generally requires long mixing and/or high turbulence (high restriction) areas so that the aqueous urea solution can be converted into NH3 without deposit formation. One alternative to dosing DEF, an aqueous solution of 32.5% wt urea, is to inject gaseous NH3.
2015-04-14
Technical Paper
2015-01-1077
Huzeifa Badshah, Imad A. Khalek
As a part of an undergraduate honor thesis project, we measured real time solid particle number and size distributions emitted from various vehicle technologies during engine start-up. Also, for a limited number of vehicles, we measured real time metallic ash particle number. A total of 85 vehicles were tested ranging from modern diesel with diesel particulate filters (DPF) to modern gasoline port fuel injected (PFI) and gasoline direct injected (GDI) engines. The testing was done at the University of Texas in San Antonio (UTSA) and at Southwest Research Institute (SwRI) parking lots. The participants were UTSA students and faculty volunteers and SwRI volunteers. For post 2007 vehicles, the work showed that diesel engines equipped with filters have significantly less particles in engine exhaust compared to gasoline PFI and especially GDI during engine start-up.
2015-04-14
Technical Paper
2015-01-1049
Christopher Depcik
The growing presence of Spark Ignition Direct Injection (SIDI) engines along with the prevalence of direct injected Compression Ignition (CI) engines results in the requirement of Particulate Matter (PM) exhaust abatement. This occurs through the implementation of Gasoline Particulate Filters (GPFs) and Diesel Particulate Filters (DPFs). Modeling of GPFs and DPFs are analogous because of the similar flow patterns and wall flow PM capture methodology. Conventional modeling techniques include a two-channel (inlet/outlet) formulation that is applicable up to three-dimensions. However, the numerical stiffness that results from the need to couple the solution of these channels in compressible flow can result in relatively long run times. Previously, the author presented a lumped DPF model using dynamically incompressible flow intended for an Engine Control Unit (ECU) in order to generate a model that runs faster than real time using a high-level programming language.
2015-04-14
Technical Paper
2015-01-1027
David Culbertson, Magdi Khair, Sanhong Zhang, Julian Tan, Jacob Spooler
SCR Cold Start Effects are increasingly important for meeting today’s emission requirements [1]. A significant challenge toward quickly achieving NOX abatement is the presence of moisture in the catalyst at lower temperatures [1]. An electric heater is able to effectively raise the temperature of the exhaust and overcome the effect of moisture, allowing NOX conversion to begin sooner. A model of the moisture storage and removal is presented, along with test results from both flow stand and engine tests. Results show that it is possible to achieve NOX conversion temperatures quickly with robust heater technology that is suited for diesel applications.
2015-04-14
Technical Paper
2015-01-1031
Nic van Vuuren, Gabriele Brizi, Giacomo Buitoni, Lucio Postrioti, Carmine Ungaro
The recent implementation of new rounds of stringent nitrogen oxides (NOx) emissions reduction legislation in Europe and North America is driving the expanded use of exhaust aftertreatment systems, including those that treat NOx under the high-oxygen conditions typical of lean-burn engines. One of the favored aftertreatment solutions is referred to as Selective Catalytic Reduction (SCR), which comprises a catalyst that facilitates the reactions of ammonia (NH3) with the exhaust nitrogen oxides (NOx). It is customary with these systems to generate the NH3 by injecting a liquid aqueous urea solution, typically at a 32% concentration of urea (CO(NH2)2). The solution is referred to as AUS-32, and is also known under its commercial name of AdBlue® in Europe, and DEF – Diesel Exhaust Fluid – in the USA. The urea solution is injected into the exhaust and transformed to NH3 by various mechanisms for the SCR reactions.
2015-04-14
Technical Paper
2015-01-0973
Aaron Brooker, Jeffrey Gonder, Lijuan Wang, Eric Wood, Sean Lopp, Laurie Ramroth
The Future Automotive Systems Technology Simulator (FASTSim) is a high level advanced vehicle powertrain analysis tool supported by the U.S. Department of Energy Vehicle Technologies Office. FASTSim provides a quick and easy way to estimate and compare the impact of technology improvements on light or heavy duty vehicle efficiency, performance, cost, and battery life. It automatically imports the required inputs for almost any existing light duty vehicle. Those inputs can be modified to represent variations of the vehicle or powertrain. The vehicle and its components are then simulated through a speed versus time drive cycle. At each time step FASTSim accounts for drag, acceleration, ascent, rolling resistance, each powertrain components’ efficiency and power limits, and regenerative braking.
2015-04-14
Technical Paper
2015-01-1684
Shivaprasad K V, Kumar GN
Fast depletion of fossil fuels and their detrimental effect to the environment is demanding an urgent need of alternative fuels for meeting sustainable energy demand with minimum environmental impact. A lot of research is being carried throughout the world to evaluate the performance, exhaust emission and combustion characteristics of the existing engines using several alternative fuels. Expert studies indicate hydrogen is one of the most promising energy carriers for the future due to its superior combustion qualities and availability. This article experimentally characterizing the combustion and emission parameters of a single cylinder high speed SI engine operating with different concentrations of hydrogen with gasoline fuel. For this purpose, the conventional carbureted high speed SI engine was modified into an electronically controllable engine, wherein ECU was used to control the injection timings and durations of gasoline.
2015-04-14
Technical Paper
2015-01-1036
Lei Liu, Zhijun Li, Boxi shen
Ensuring lower emissions and better economy (fuel economy and after-treatment economy) simultaneously is the pursuit of future engines. An EGR-LNT synergetic control system was applied to a modified lean-burn gasoline engine of CA3GA2. Results showed that the synergetic control system can achieve a better NOx reduction than sole EGR and sole LNT within a proper range of upstream EGR rate without the penalty in fuel consumption, and it also has the potential to saving noble metal cost in LNT. But more or less upstream EGR rate would make the synergetic control system inefficiency. In order to guarantee the objectivity of the effect of EGR-LNT synergetic control system on NOx Reduction, another modified lean-burn gasoline engine of CA4GA5 was additionally tested. Results verified that proper range of upstream EGR rate in EGR-LNT synergetic control system.
2015-04-14
Technical Paper
2015-01-1264
Junseok Chang, Yoann Viollet, Abdullah Alzubail, Amir Faizal Naidu Abdul-Manan, Abdullah Al Arfaj
This paper explores the potential for reducing transport-related greenhouse gas (GHG) emissions by introducing high-efficiency spark-ignition engines with a dual-fuel injection system to customize octane of the fuels based on real-time engine requirements. Recent study [1] shows that 4-6% GHG emissions can be reduced by replacing 2/3 light duty vehicle fleet with high efficiency engines that are designed with higher compression ratio and boost levels. However, this can be only possible if premium gasoline fuel (Research Octane Number, RON=98 or 100) is readily available on a large scale to supply a fleet demand. From a refinery perspective, increasing the octane of the fuels to such high levels could potentially require significant and costly upgrades to the reforming and isomerization units as well as lower gasoline yield, and thus, this is not an economically attractive option for many of the refiners. In our study, we considered different strategy.
2015-04-14
Technical Paper
2015-01-0809
Joonsik Hwang, Yongjin Jung, Choongsik Bae
The effect of biodiesel produced from waste cooking oil (WCO) on the soot particles of a compression ignition diesel engine was experimentally investigated and compared with conventional diesel fuel. The indicated mean effective pressure of approximately 0.75 MPa was tested under an engine speed of 1200 revolutions per minute. The fuels were injected at an injection timing of -5 crank angle degree after top dead center with injection pressures of 80 MPa. Detailed characteristics of particulate matters were analyzed in terms of transmission electron microscopy (TEM), thermogravimetric analysis and elemental analysis. For the work, soot aggregates were collected with a thermophoretic sampling device installed in the exhaust pipe of the engine. High-resolution TEM images revealed that the WCO biodiesel soot was composed of smaller primary particle than diesel soot. The mean primary particle diameter was measured as 19.9 nm for WCO biodiesel and 23.7 nm for diesel, respectively.
2015-04-14
Technical Paper
2015-01-1008
Vitaly Prikhodko, Josh Pihl, Todd Toops, John Thomas, James Parks, Brian West
Ethanol is a very effective reductant of nitrogen oxides (NOX) over silver/alumina (Ag/Al2O3) catalysts in lean exhaust environment. With the widespread availability of ethanol/gasoline-blended fuel in the USA, lean gasoline engines equipped with an Ag/Al2O3 catalyst have the potential to deliver higher fuel economy than stoichiometric gasoline engines and to increase biofuel utilization while meeting exhaust emissions regulations. In this work a pre-commercial 2 wt% Ag/Al2O3 catalyst was evaluated on a 2.0-liter BMW lean burn gasoline direct injection engine for the selective catalytic reduction (SCR) of NOX with ethanol/gasoline blends. The ethanol/gasoline blends were delivered via in-pipe injection upstream of the Ag/Al2O3 catalyst with the engine operating under lean conditions. A number of engine conditions were chosen to provide a range of temperatures and space velocities for the catalyst performance evaluations.
2015-04-14
Technical Paper
2015-01-0983
Mohd Abas, Ricardo Martinez-Botas
Cylinder deactivation has been utilized by vehicle manufacturers since the 80s to improve fuel economy and exhaust emissions. Cylinder deactivation is achieved by cutting off fuel supply and ignition in some of the engine cylinders, while their inlet and outlet valves are fully closed. The vehicle demand during cylinder deactivation is sustained by only the firing cylinders, hence increasing their indicated power. Conventionally, half the numbers of cylinders are shut at certain driving conditions, which normally at the lower demand regime. Optimal strategy ensures cylinder deactivation significantly contributes to fuel consumption without compromising the vehicle drivability. Fuel consumption with cylinder deactivation has been documented to generally improve between 6 to 25 %, depending on the type-approval test drive cycles. However, type-approval test has been reported to differ from the “real-world” fuel consumption values.
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