Browse Topic: Three-way catalysts

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BALL BEARINGS.06000204/23/2025
HESS, HENRY
Three way Catalyst with faster light-off substrates – A promising approach to reduce tailpipe emissions2024-26-014201/16/2024
The ever-tightening regulation norms across the world emphasize the magnitude of the air pollution problem. The decision to leapfrog from BS4 to BS6 - with further reduction in emission limits - showed India's commitment to clean up its atmosphere. The overall cycle emissions were reduced significantly to meet BS6 targets. However, the introduction of RDE norms in BS6.2 demanded further reduction in emissions under real time operating conditions - start-stop, hard acceleration, and idling, cold start - which was possible only through strategies that demanded a cost effective yet robust solutions. The first few seconds of the engine operation after start contribute to major amount to the cycle gaseous emissions. This is because the thermal inertia of the catalytic converter restricts the rate at which temperature of the catalyst increases and achieves the desired "light-off" temperature. The challenge becomes more prominent in the turbocharged engines which puts additional heat 'loss
Kale, Vishal Maruti, M, Ravisankar, Hosur, Viswanatha, Sridhar, S, Bhimavarapu, Aditya, Lende, Nilesh Ashok, Rose, Dominik, Tao, Tinghong
Novel Pt/Rh coated gasoline particle filter development and its application2022-01-066103/29/2022
With the stringent China6 legislation implementation in 2020, Gasoline Particular Filters (GPF) are widely applied to control Particle Number (PN), THC, CO, and NOx emissions from gasoline engines. The typical GPF product in the market is usually coated with a Pd/Rh three-way catalyst (TWC). In this work, a novel and cost-effective GPF was achieved through Pd substitution with lower cost Pt in a novel Pt/Rh TWC coating. The Pt/Rh GPF was evaluated for back pressure (BP) under clean and soot loaded conditions, PN Filtration efficiency, TWC activity, and soot regeneration. The aged Pt/Rh GPF gave superior TWC performance.
Qiao, Dongsheng, Pan, Xinbo, He, Jun, Chen, Jiahao, Ji, Hongyu, Andersen, Paul
Real World Emissions Analysis Using Sensor-based Emissions Measurement System for Light-duty Direct-Injection Gasoline Vehicle2022-01-068603/29/2022
In recent years, particulate matter (PM) emitted from direct-injection gasoline vehicles has become a problem. In addition, it is often reported that ammonia (NH3) is emitted from gasoline vehicles equipped with a three-way catalyst. These emissions might be largely emitted especially when driving in on-road driving conditions. In this study, we investigated the emissions, NOx, NH3, and PM / PN (particulate number) of a light-duty direct-injection gasoline vehicle when driving on actual roads. Using a small direct-injection gasoline vehicle equipped with a three-way catalyst, we ran nine times on the same route and measured these emissions. Based on these measurements, we analyzed "where" and "how much" NOx, NH3, and PM / PN were emitted. As a result, it was clarified that a large amount of NOx is emitted after the fuel is cut during deceleration, NH3 is emitted when the air-fuel ratio becomes rich, and PM / PN is emitted during rapid acceleration of the vehicle. Then, the relationship
Eang, Chanpaya, Sato, Susumu, Tanaka, Kotaro, Tange, Takeshi, Chen, Jiaxin
A Study of Emission Durability and Ash Accumulation of “Advanced Three-Way Catalyst Integrated on Gasoline Particulate Filter” for BS6 (Stage2) Applications2021-26-018209/22/2021
India BS6 Stage2 (2023) regulations demands all Gasoline direct injection (GDI) vehicles to meet particulate number emissions (PN) below 6x10+11# per km. Gasoline particulate filters (GPF) are a proven technology and enable high PN filtration efficiencies throughout the entire vehicle lifetime. One challenge for GPF applications could be the changing emission performance characteristics as a function of mileage due to collected ash and/or soot deposits with implications on back pressure losses and well due to aging of active catalytic components like PGM and Washcoat. The main objective of this technical contribution is to study the above-mentioned challenges while applying Indian driving conditions and typical Indian climate and other ambient conditions. The substrate technology selected for this study is a high porosity GPF designed to enable the integration of a Three-Way functionality into the GPF, commonly described as coated GPF. In this study, the entire Three-Way Catalyst (TWC
Rose, Dominik, Tao, Tinghong, Kataria, Rohit, Boger, Thorsten, Kuehn, Nikolas, Kunert, Susanne, Richter, Joerg Michael, Magar, Avinash
A New Catalyst Technology to overcome Diffusion and Transport Limitations2021-26-021009/22/2021
The purification efficiency of exhaust gas catalysts depends on several factors. One of the most important factors is the diffusivity of the exhaust gases in the catalytic coating layer, especially at moderate to high temperature and space velocity conditions. Porous silica, γ-alumina, zirconia, carbons and many other porous crystalline materials that are commonly used as catalysts and catalyst supports are traversed by a labyrinth of tortuous micro and mesopores. If the connectivity is very low, the labyrinth of pores becomes more difficult to penetrate, increasing the overall “tortuosity” and slowing down the transportation of gas molecules within catalyst layers. A new approach to overcome these diffusion and transport limitations in an exhaust gas catalyst is to create an interconnected network of mesopores and macropores via increase in void fractions within the washcoat components and layers. In this study, various organic and inorganic pyrolyzable pore forming agents (PFAs) were
Gaur, Kanishka, Muthusamy, Vishnuvarthan, Mishra, Sushil, Kukreti, Sumit, Rajan, Bosco, Bartley, Gordon, Trigunayat, Alok
A Novel Integrated Series Hybrid Electric Vehicle Model Reveals Possibilities for Reducing Fuel Consumption and Improving Exhaust Gas Purification Performance2021-01-124409/21/2021
This paper describes the development of an integrated simulation model for evaluating the effects of electrically heating the three-way catalyst (TWC) in a series hybrid electric vehicle (s-HEV) on fuel economy and exhaust gas purification performance. Engine and TWC models were developed in GT-Power to predict exhaust emissions during transient operation. These models were validated against data from vehicle tests using a chassis dynamometer and integrated into an s-HEV model built in MATLAB/Simulink. The s-HEV model accurately reproduced the performance characteristics of the vehicle’s engine, motor, generator, and battery during WLTC mode operation. It can thus be used to predict the fuel consumption, emissions, and performance of individual powertrain components. The engine combustion characteristics were reproduced with reasonable accuracy for the first 50 combustion cycles, representing the cold-start condition of the driving mode. Analysis of the TWC performance using the model
Yamagishi, Takehiro, Shingyouchi, Hajime, Yamaguchi, Kyohei, Mizushima, Norifumi, Noyori, Takahiro, Kusaka, Jin, Okajima, Toshinori, Sok, Ratnak, Nagata, Makoto
Three-way catalyst model development using physical and machine learning methods for engine control design purposes2021-01-122109/21/2021
Gasoline engine control strategies ensure a combustion control around stoichiometry. That is because the three-way catalytic converter allows CO and HC oxidation under lean operating conditions while ensuring NOx reduction for rich mixtures. In case of engine malfunction, the controller must adapt to compensate for potential torque losse and other critical attributes, potentially leading to significant deviation of the fuel-air mixture richness from stoichiometry and larger emission levels. Therefore, during development of the engine fault diagnostics the impact on the pollutant emissions must be considered. In this paper, a model-based development process is proposed. It is based on system simulation modelling techniques, where a complete exhaust line is represented in order to predict tail-pipe emissions under stoichiometric, lean and rich conditions, for engine control design purposes. Two different modelling approaches are applied and evaluated in this paper. First, a physics-based
LOUSSAIEF, Sana, Akhmetov, Yerlan, GROISIL, Melanie, Takahashi, Daisuke, Kuhara, Masaki, Isobe, Yoshiki, Mas, Peter
Oxygen Storage Capacity (OSC) Measurement of 3-Way Automotive Catalysts Using the CATAGEN OMEGA Test Reactor2021-24-008309/05/2021
A Three-way automotive catalyst's ability to store oxygen is still a crucial performance metric for modern day catalyst applications. With more stringent emissions legalisation, the oxygen storage capacity (OSC) within the catalyst can assist with converting different exhaust gases such as CO, THC and NOx under transient operating conditions. OSC is currently the only onboard catalyst performance metric recorded during a vehicle's useful life. Catalyst performance is correlated to this OSC measurement. Rhodium is a precious metal used in automotive catalysts to help with the conversion of NOx. The price of rhodium is increasing drastically, requiring original equipment manufacturers (OEMs) to look at cost-effective alternatives to maintain NOx conversion within the exhaust stream. OSC in the catalyst is possible due to ceria in the washcoat. Stored oxygen can help promote other reactions in the catalyst bed to help with the conversion of NOx. For a catalyst's OSC to be fully understood
Mc Grane, Liam, Douglas, Roy, Irwin, Kurtis, Woods, Andrew, Stewart, Jonathan, Pedlow, Andrew, Elliott, Matthew
A Control-Oriented Spatially Resolved Thermal Model of the Three-Way-Catalyst2021-01-059704/06/2021
The three-way-catalyst (TWC) is an essential part of the exhaust aftertreatment system in spark-ignited powertrains, converting nearly all toxic emissions to harmless gasses. The TWC’s conversion efficiency is significantly temperature-dependent, and cold-starts can be the dominating source of emissions for vehicles with frequent start/stops (e.g. hybrid vehicles). In this paper we develop a thermal TWC model and calibrate it with experimental data. Due to the few number of state variables the model is well suited for fast offline simulation as well as subsequent on-line control, for instance using non-linear state-feedback or explicit MPC. Using the model could allow an on-line controller to more optimally adjust the engine ignition timing, the power in an electric catalyst pre-heater, and/or the power split ratio in a hybrid vehicle when the catalyst is not completely hot. The model uses a physics-based approach and resolves both axial and radial temperature gradients, allowing for
Lock, Jonathan, Clasen, Kristoffer, Sjoblom, Jonas, McKelvey, Tomas
Investigation and 1D Modelling Approach on Scavenging Air Post-Oxidation inside the Exhaust Manifold of a DISI Engine2021-01-059904/06/2021
The introduction of real driving emission measurements increases the need of improved transient engine behavior while keeping the emissions to a minimum. A possible way of enhancing the transient engine behavior is the targeted usage of scavenging. Scavenging is realized by an inlet- and exhaust-valve overlap. Fresh scavenging air flows directly from intake manifold through the cylinder into the exhaust manifold. Therefore, the mass flow at the turbine increases and causes a reduced turbo lag, which results in a more dynamic engine behavior. The unburned oxygen causes a decrease of the three-way catalyst (TWC) conversion rate. To keep the TWC operation close to stoichiometry, a rich combustion is performed. The rich combustion products (most notably carbon monoxide) mix in the exhaust manifold and react with oxygen so that the conversion rate of the TWC is ensured. In order to investigate the potential and risks of this engine operating strategy, a reliable 1D engine model is necessary
Przewlocki, Jan, Tromellini, Rodolfo, Grill, Michael, Chiodi, Marco, Bargende, Michael
Exhaust Emissions from an SUV with a Spark-Ignition Engine Tested Using EU and US Legislative Driving Cycles and EU RDE Procedures2021-01-061604/06/2021
Despite an overall trend towards harmonization in vehicle regulations, regional differences persist in the area of exhaust emissions and fuel economy. The test procedure employed can exert a significant impact on the results obtained. In this paper, the EU and US type approval procedures for light duty vehicles are briefly compared and results obtained from several types of test procedure are presented. Specifically, emissions tests were performed on a single SUV which met US Tier III emissions limits. The vehicle featured a conventional, naturally aspirated spark ignition engine with indirect fuel injection and an aftertreatment system consisting of three-way catalysts with no dedicated particulate filtration device. The vehicle’s engine displacement, total mass and power-to-mass ratio were relatively representative of the upper end of the US market, but represented an outlying vehicle in terms of the characteristics of the EU fleet. The following test procedures were used: the
Bielaczyc, Piotr, Woodburn, Joseph
Performance of Bi-Fuel Ethanol-Methane SI-Engine for Stage V Non-Road Applications2020-01-204309/15/2020
Due to agricultural engines’ high average workload and operation in rural areas, substituting internal combustion engines in non-road sector is still a challenge. Utilizing sustainable solutions are therefore in key position for decarbonizing the non-road sector. To this day, the diesel engines dominate the markets because of their high efficiency. However, the simplicity and cost effectiveness of the spark-ignited engines together with renewable fuels are suggested to bring several advantages compared to the diesel engine. E.g. ethanol and bio methane are relatively simple to produce from agricultural residuals and wastes, and the raw materials are easily available around the world. Additionally, stoichiometric engines would only require a three-way catalyst (TWC) to fulfil Stage V emission regulations. A bi-fuel (BF) and dual-fuel (DF) engine operating on both ethanol and biogas could potentially offer a flexible option for e.g. farmers, as they could produce the fuels locally and
Pettinen, Rasmus, Soderena, Petri, Westerholm, Mårten, Nyyssönen, Sami, Söderström, Christer, Martikainen, Jarno
The Diesel Aftertreatment Accelerated Aging Cycle Protocol: An Advanced Aftertreatment Case Study2020-01-221009/15/2020
As agencies and governing bodies evaluate the feasibility of reduced emission standards, additional focus has been placed on technology durability. This is seen in proposed updates, which would require Original Equipment Manufacturers (OEMs) to certify engine families utilizing a full useful life (FUL) aftertreatment system. These kinds of proposed rulings would place a heavy burden on the manufacturer to generate FUL components utilizing traditional engine aging methods. Complications in this process will also increase the product development effort and will likely limit the amount of aftertreatment durability testing. There is also uncertainty regarding the aging approach and the representative impact compared to field aged units. Existing methodologies have evolved to account for several deterioration mechanisms that, when controlled, can be utilized to create a flexible aging protocol. As a result, these methodologies provide the necessary foundation for continued development. The
Zavala, Bryan, Vats, Shekhar, Eakle, Scott
Accelerated Ageing Method of Three Way Catalyst Run on Test Bed with Emission Performance and Oxygen Storage Capacity Evaluation2020-01-218909/15/2020
The aim of this paper was to describe a method of accelerated three way catalytic converter (TWC) ageing performed on the engine test bed for European On Board Diagnostics (EOBD) monitoring purposes and screening of different catalysts solutions. To accelerate the catalyst ageing process, the exhaust gas temperature was elevated to a range 1000 - 1200°C, which is typical for an ageing cycle performed using ovens. Catalyst emissions performance was checked at new condition (after degreening) and subsequently at predefined ageing intervals, based on the oxygen storage capacity (OSC) evaluation. The emission tests were performed in the laboratory on the chassis dynamometer using legislative cycles. The accelerated ageing method was found to be of use for verifying the EOBD functionality under vehicle operation with a degraded catalyst substrate. Secondly, the described method allows execution of a time-efficient ageing cycle on a test bed in order to validate catalyst chemistry and
Sala, Rafal, Bielaczyc, Piotr
Impact of Thermal Management of the Three-Way Catalyst on the Energy Efficiency of a P2 Gasoline FHEV2020-37-001906/23/2020
Gasoline Full Hybrid Electric Vehicles (FHEVs) are recognized as a cost-effective solution to comply with upcoming emissions legislation. However, several studies have highlighted that frequent start-and-stops worsen the HC tail-pipe emissions, especially when the light-off temperature of the three-way catalyst (TWC) has not been reached. In fact, strategies only addressing the minimization of fuel consumption tend to delay engine activation and hence TWC warming, especially during urban driving. Goal of the present research is therefore to develop an on-line powertrain management strategy accounting also for TWC temperature, in order to reduce the time needed to reach TWC light-off temperature. A catalyst model is incorporated into the model of the powertrain where torque-split is performed by an adaptive equivalent consumption minimization strategy (A-ECMS). The developed A-ECMS operates on a domain of power-split combinations between electric machine and internal combustion engine
Benegiamo, Marco, Valletta, Andrea, Carlucci, Antonio, Mulone, Vincenzo
Characteristics of Transient NOx Emissions of HEV under Real Road Driving2020-01-038004/14/2020
To meet the request of China National 6b emission regulations which will be officially implemented in China, firstly including the RDE emission test limits, the transient emissions on real road condition are paid more attention. A non-plug-in hybrid light-duty gasoline vehicles (HEV) sold in the Chinese market was selected to study real road emissions employed fast response NOx analyzer from Cambustion Ltd. with a sampling frequency of 100Hz, which can measure the missing NO peaks by standard RDE gas analyzer now. Emissions from PEMS were also recorded and compared with the results from fast response NOx analyzer. The concentration of NOx emissions before and after the Three Way Catalyst (TWC) of the hybrid vehicle were also sampled and analyzed, and the working efficiency of the TWC in real road driving process was investigated. It is found that when the engine is at high-speed and heavy-load conditions, especially when fuel is injected after fuel cut, instantaneous spikes in tailpipe
Zhang, Yonghao, Deng, Jun, Li, Qiang, Liu, Yintong, He, Bo, Hu, Zongjie, Bo, Shi, Li, Liguang
Effects of Using an Electrically Heated Catalyst on the State of Charge of the Battery Pack for Series Hybrid Electric Vehicles at Cold Start2020-01-044404/14/2020
Battery models are being developed as a component of the powertrain systems of hybrid electric vehicles (HEVs) to predict the state of charge (SOC) accurately. Electrically heated catalysts (EHCs) can be employed in the powertrains of HEVs to reach the catalyst light off temperature in advance. However, EHCs draw power from the battery pack and hence sufficient energy needs to be stored to power auxiliary components. In series HEVs, the engine is primarily used to charge the battery pack. Therefore, it is important to develop a control strategy that triggers engine start/stop conditions and reduces the frequency of engine operation to minimize the equivalent fuel consumption. In this study, a battery pack model was constructed in MATLAB-Simulink to investigate the SOC variation of a high-power lithium ion battery during extreme engine cold start conditions (-7°C) with/without application of an EHC. The EHC was simulated in MATLAB to determine the energy required to heat the catalyst
Sivakumar, Suchitra, Shingyouchi, Hajime, Yan, Xieyang, Okajima, Toshinori, Yamaguchi, Kyohei, Kusaka, Jin, Nagata, Makoto
Effect of Driving Cycles on Emissions from On-Road Motorcycles2020-01-037704/14/2020
Chassis dynamometer testing was conducted with three on-highway motorcycles produced for the North American market with engine displacements of 296 cc, 749 cc and 1198 cc to better inform criteria pollutant emissions inventories. The motorcycles were tested using US Tier 2 certification fuel over the Federal Test Procedure (FTP), World Motorcycle Test Cycle (WMTC) and a cycle based on a sample of real-world motorcycle driving, informally referred to as the ‘Real World Driving Cycle’ (RWDC). Emissions characterization includes composite, individual test phase and 1Hz cumulative results for various criteria pollutants for each test cycle. Overall, it was found that the higher peak speed rates and peak torque levels observed during the RWDC are more fully represented in the WMTC than the FTP. The use of the WMTC and RWDC cycles generally translated into higher emissions rates compared to the FTP and in particular for nitrogen oxides and carbon monoxide. As well, the three test drive
Rosenblatt, Debbie, Stokes, Jonathan, Caffrey, Cheryl, Brown, Kevin F.
Control Oriented Physics Based Three-Way Catalytic Converter Temperature Estimation Model for Real Time Controllers2020-01-090404/14/2020
As automotive emissions become more stringent, accurate control of three-way catalyst temperature is increasingly important for maintaining high levels of conversion efficiency as well as preventing damage to the catalyst. A real-time catalyst temperature model provides critical information to the engine control system. In order to improve emissions and ensure regulatory compliance over a wide range of speed-load conditions, it is desirable to use modelled catalyst temperature as the primary input to catalyst efficiency control strategies. This requirement creates a challenge for traditional empirical models designed for component protection at high speed-load conditions. Simulation results show that a physics aligned model can estimate temperature in all operating conditions, including: cold-start, extended idle, engine shutdown, stop-start events, decel fuel shut-off, as well as traditional high load and part load points. However, physics based approaches which calculate detailed
Shah, Darshan, Premchand, Kiran, Pedro, David
Effects of Sub-Chamber Configuration on Heat Release Rate in a Constant Volume Chamber simulating Lean-burn Natural Gas Engines2019-32-055101/24/2020
Sub-chamber is a useful device with regard to sustaining stable operation of compressed natural gas (CNG) engines under lean burn conditions. In our previous studies, we applied a sub-chamber injection system to CNG engines, in which a single injector and a spark plug are mounted in a small sub-chamber. The aim of this study is to investigate the effect of the sub-chamber configuration on heat release in the main combustion chamber. 11 types of sub-chamber with different nozzle number, nozzle diameter, and sub-chamber volume were examined under a condition that pressure is 2.3 MPa, and global equivalence ratio is 0.6. When the sub-chamber with smaller nozzles are used, the penetration velocity of burned gas jet increases. In addition, the velocity also increases with an increasing sub-chamber volume. The high-speed penetration of burned gas jet shortens the period of initial flame development. This is because the high-temperature burned gas quickly reaches to side wall of main chamber
Nada, Yuzuru, Kidoguchi, Yoshiyuki, Yamashita, Yuto, Furukawa, Ryo, Kaya, Ryu, Nakano, Hideaki, Kobayashi, Shinichi
Analysis and Automated Detection of Ice Crystal Icing Conditions Using Geostationary Satellite Datasets and In Situ Ice Water Content Measurements2019-01-195306/10/2019
Recent studies have found that high mass concentrations of ice particles in regions of deep convective storms can adversely impact aircraft engine and air probe (e.g. pitot tube and air temperature) performance. Radar reflectivity in these regions suggests that they are safe for aircraft penetration, yet high ice water content (HIWC) is still encountered. The aviation weather community seeks additional remote sensing methods for delineating where ice particle (or crystal) icing conditions are likely to occur, including products derived from geostationary (GEO) satellite imagery that is now available in near-real time at increasingly high spatio-temporal detail from the global GEO satellite constellation. A recent study using a large sample of co-located GEO satellite and in-situ isokinetic evaporator probe (IKP-2) total water content (TWC) datasets found that optically thick clouds with tops near to or above the tropopause in close proximity (≤ 40 km) to convective updrafts were most
Bedka, Kristopher, Yost, Christopher, Nguyen, Louis, Strapp, J. Walter, Ratvasky, Thomas, Khlopenkov, Konstantin, Scarino, Benjamin, Bhatt, Rajendra, Spangenberg, Douglas, Palikonda, Rabindra
Event-Driven Simulation of Particle-Particle and Particle-Surface Collisions in Ice Crystal Icing2019-01-201406/10/2019
This paper describes an event-driven simulation tool for predicting particle-particle and particle-surface interactions in ice crystal icing (ICI). A new accretion model which is much less empirical than existing models for predicting ICI accretion is also described. Unlike previous models, the new “gouge/bounce model” (GBM) differentiates between (erosion) losses resulting from particle bounce and those resulting from particle gouging. A bounce threshold based on the tangential Stokes number is used to calculate most of the bounce loss. The GBM also predicts ejecta velocities and directions, at least approximately, which is important because most of the mixed-phase mass flux impacting a surface actually bounces off or erodes existing material in ICI, thereby increasing the mass flux downstream. The event-driven simulation tool, denoted COLLIDE, has been applied to two test cases in which accretion growth appeared to be affected by TWC in a manner beyond that which would be expected
Currie, Thomas Charles
High Load Expansion of Catalytic EGR-Loop Reforming under Stoichiometric Conditions for Increased Efficiency in Spark Ignition Engines2019-01-024404/02/2019
The use of fuel reformate from catalytic processes is known to have beneficial effects on the spark-ignited (SI) combustion process through enhanced dilution tolerance and decreased combustion duration, but in many cases reformate generation can incur a significant fuel penalty. In a previous investigation, the researchers showed that, by controlling the boundary conditions of the reforming catalyst, it was possible to minimize the thermodynamic expense of the reforming process, and in some cases, realize thermochemical recuperation (TCR), a form of waste heat recovery where exhaust heat is converted to usable chemical energy. The previous work, however, focused on a relatively light-load engine operating condition of 2000 rpm, 4 bar brake mean effective pressure (BMEP). The present investigation demonstrates that this operating strategy is applicable to higher engine loads, including boosted operation up to 10 bar BMEP. By controlling the reforming catalyst boundary conditions, it is
Szybist, James P., Pihl, Josh, Huff, Shean, Kaul, Brian
Review of Vehicle Engine Efficiency and Emissions2019-01-031404/02/2019
This review paper covers major regulatory and technology developments in 2018 pertinent to tailpipe emissions of greenhouse gases and criteria pollutants. Europe has proposed ambitious reductions in CO2 limits for both light- and heavy-duty sectors. The challenge is compounded with changing measurement norms and a significant shift away from fuel efficient diesels in the light-duty (LD) space. Both incremental and step changes are being made to advance internal combustion. New studies show that in-use NOx emissions from diesels can be much lower than required by the Euro 6 regulation. Discussions have already started on Euro 7 regulations, and the leading regulatory concepts and proposed technical solutions are provided. In the heavy-duty (HD) sector, the progress is outlined in improving engine and vehicle fuel efficiency through the US Department of Energy’s (DOE’s) SuperTruck II program and other representative studies. Common approaches among the participants include hybridization
Joshi, Ameya
Fuel Reforming and Catalyst Deactivation Investigated in Real Exhaust Environment2019-01-031504/02/2019
Increased in-cylinder hydrogen levels have been shown to improve burn durations, combustion stability, HC emissions and knock resistance which can directly translate into enhanced engine efficiency. External fuel reformation can also be used to increase the hydrogen yield. During the High-Efficiency, Dilute Gasoline Engine (HEDGE) consortium at Southwest Research Institute (SwRI), the potential of increased hydrogen production in a dedicated-exhaust gas recirculation (D-EGR) engine was evaluated exploiting the water gas shift (WGS) and steam reformation (SR) reactions. It was found that neither approach could produce sustained hydrogen enrichment in a real exhaust environment, even while utilizing a lean-rich switching regeneration strategy. Platinum group metal (PGM) and Ni WGS catalysts were tested with a focus on hydrogen production and catalyst durability. Although 4% additional hydrogen was initially produced in the EGR stream, leading to improvements in the coefficient of
Bartley, Gordon, Gukelberger, Raphael, Henderson, Robert, Henry, Cary
Diagnostics of Field-Aged Three-Way Catalyst (TWC) on Stoichiometric Natural Gas Engines2019-01-099804/02/2019
Three-way catalysts have been used in a variety of stoichiometric natural gas engines for emission control. During real-world operation, these catalysts have experienced a large number of temporary and permanent deactivations including thermal aging and chemical contamination. Thermal aging is typically induced either by high engine-out exhaust temperatures or the reaction exotherm generated on the catalysts. Chemical contamination originates from various inorganic species such as Phosphorous (P) and Sulfur (S) that contain in engine fluids, which can poison and/or mask the catalyst active components. Such deactivations are quite difficult to simulate under laboratory conditions, due to the fact that multiple deactivation modes may occur at the same time in the real-world operations. In this work, a set of field-aged TWCs has been analyzed through detailed laboratory research in order to identify and quantify the real-world aging mechanisms. Based on the measured NOx conversion
Wang, Di, An, Hongmei, Gong, Jian, Li, Junhui, Kamasamudram, Krishna, Currier, Neal, Yezerets, Aleksey
Optimized Driving Cycle Oriented Control for a Highly Turbocharged Gas Engine2019-01-019304/02/2019
The article is focused on a 1-D drive dynamic simulation of a highly turbocharged gas engine. A mono fuel CNG engine has been developed as a downsized replacement of the diesel engine for a medium size van. The basic engine parameters optimization is provided in a steady state operation and a control adjustment is applied to a dynamic vehicle model for a transient response improvement in highly dynamic operation modes of the WLTC (world light duty test cycle), selected for investigation. Vehicle simulation model with optimized control system is used for driving cycle fuel consumption and CO2 emissions predictions compared with the basic engine settings.
Dolecek, Vit, Vavra, Jiri, Skarohlid, Marcel
Regeneration Strategies for Gasoline Particulate Filters2019-01-096904/02/2019
Gasoline particulate filters (GPFs) are extremely effective at reducing tailpipe emissions of particulate mass and particulate number. Especially in the European and Chinese markets, where a particulate number standard is legislated, we see gasoline particulate filters being deployed in production on gasoline direct injected engines. Due to the high temperature in gasoline exhaust, most applications are expected to be passively regenerating without the help of an active regeneration strategy. However, for the few cases where a customer drive cycle has consistently low speed over a long time frame, an active regeneration strategy may be required. This involves increasing the exhaust temperature at the GPF up to around 600 degC so that soot can be combusted. We compare two different ways of achieving these temperatures, namely spark retard and air fuel ratio modulation. The former generates heat in the engine, the latter generates heat in one or more catalysts in the exhaust system. We
Van Nieuwstadt, Michiel, Shah, Anil, Serban, Emil, Martin, Douglas
Investigation of an Advanced Combustion System for Stoichiometric Diesel to Reduce Soot Emissions2019-01-002301/15/2019
Diesel engines are facing increased competition from gasoline engines in the light-duty and small non-road segments, primarily due to the high relative cost of emissions control systems for lean-burn diesel engines. Advancements in gasoline engine technology have decreased the operating cost advantage of diesels and the relatively high initial-cost disadvantage is now too large to sustain a strong business position. SwRI has focused several years of research efforts toward enabling diesel engine combustion systems to operate at stoichiometric conditions, which allows the application of a low-cost three-way catalyst emission control system which has been well developed for gasoline spark-ignited engines. One of the main barriers of this combustion concept is the result of high smoke emissions from poor fuel/air mixing. The current study focuses on improving the combustion system by investigating different fuel/air mixing strategies that enhance fuel spray - piston bowl interaction while
Chase, Avery, Miwa, Jason, Abidin, Zainal, Cung, Khanh
Optimization of Performance of Oxygen Storage Component (OSC) for NO Reduction in Three Way Catalysts to Achieve BS VI Emission Norms2019-26-013301/09/2019
Current restrictions on environmental pollution worldwide has created the need for new methodologies and technology development which should not only ensure ultra-low emission level from different categories of engine but should also use less fuel resulting in lower carbon dioxide (CO2) emissions. The state-of-art technology to achieve ultra-low emissions placed after engine in exhaust line is a ‘catalytic converter’. Catalytic converter is an after treatment device which typically oxidizes or reduces the toxic pollutants emitted by any engine to carbon dioxide (CO2), nitrogen (N2) and water (H2O). Catalytic converters used in Gasoline / CNG operated vehicles contains oxygen storage component as a key component for supplying oxygen in rich mode of operation and the oxygen concentration release rate is function of gas concentration and air to fuel ratio (A/F) or lambda (λ). Conventionally, the vehicles (two wheelers) operated using mechanical method such as carburetor, a source for
Kumar, Arvind, Rajan, Bosco, Harkonen, Matti, Trigunayat, Alok, Muthusamy, Vishnuvarthan, Mishra, Sushil
Impact of Secondary Air Injection on Small Engine Motorcycle Intended for BS VI Applications2018-32-006810/30/2018
On April 2020, India will move from Bharat Stage IV to Bharat Stage VI where the combined emission limit of Total Hydrocarbons (THC) and Nitrogen oxides (NOx) of 0.79g/km will independently reduce to 0.1g/km and 0.06g/km respectively. This reduction in emission limit however may prove to be challenging for small engines (below 200 cc) with the existing generation of engines predominantly in cold operating conditions. When the vehicle is started after soaking (engine turned off for few hours), considerable amount of THC emission is generated which can be attributed to poor fuel vaporization and incomplete combustion due to flame quenching in the combustion chamber. Also, the catalyst is inactive to chemical reactions until the accumulated heat energy from the hot exhaust mass flow elevates the catalyst temperature to facilitate efficient conversion of THC, CO and NOx to H2O, CO2 and N2. This temperature point is termed as catalyst light off temperature. Hence, most of the tail pipe
Sabu, Abhijith, Reddemreddy, Pramod, Parmar, Manojkumar
Emission Control System Designing to Meet China 62018-01-170609/10/2018
China 6 will be implemented from Jul 1st 2020, containing two norms, China 6a and China 6b. China 6a brings an introduction of the WLTC and a PN limit of 6 x 1011 #/km. Emissions limits of THC, CO and NOx, in China 6a are similar to China 5. Overall China 6a sets a similar emissions challenge to Euro 6d. In areas where China 6b is introduced before national roll out, we will see a further tightening in gaseous emissions to around half of China 6a levels for THC, CO and NOx. This therefore presents a very challenging situation for emissions control system design, particularly because of both the stringent gaseous requirement in China 6b and the PN requirement. In this paper, one development stage vehicle, equipped with a 1.5 L Gasoline Direct Injection (GDI) engine, was chosen for investigation. Firstly, after a calibration modification, 3 TWC systems with variable PGM loading were evaluated. The results showed the systems with a PGM loading higher than 40 g/ft3 for the front brick
Zhang, Qingmao, Ren, Xiangfei, Wu, Xiangke, Li, Jin, Chen, Chu, Wang, Jiangwei, Sun, Yinglei, Ji, Hongyu, Chen, Shengdian
Passive Metal Hydride Module Concept for Enhanced Low-Temperature Catalyst Performance2018-01-500105/04/2018
A technology concept applicable to stoichiometric and lean burn engine operation-a metal hydride (MHx) module for the generation of H2 via reaction with gaseous H2O-was evaluated for the introduction of low levels of H2 (ca. 500 ppmv) into internal combustion engine exhaust for the enhancement of catalyst performance at low temperatures, such as during cold-start. Projected MHx module packaging volume, replacement frequency, and costs over the lifetime of a light duty vehicle are excessive, and considered prohibitive to technology viability.
Bradford, Michael C.
Passive Hydrocarbon Trap to Enable SULEV-30 Tailpipe Emissions from a Flex-Fuel Vehicle on E85 Fuel2018-01-094404/03/2018
Future LEV-III tailpipe (TP) emission regulations pose an enormous challenge forcing the fleet average of light-duty vehicles produced in the 2025 model year to perform at the super ultralow emission vehicle (SULEV-30) certification levels (versus less than 20% produced today). To achieve SULEV-30, regulated TP emissions of non-methane organic gas (NMOG) hydrocarbons (HCs) and oxygenates plus oxides of nitrogen (NOx) must be below a combined 30 mg/mi (18.6 mg/km) standard as measured on the federal emissions certification cycle (FTP-75). However, when flex-fuel vehicles use E85 fuel instead of gasoline, NMOG emissions at cold start are nearly doubled, before the catalytic converter is active. Passive HC traps (HCTs) are a potential solution to reduce TP NMOG emissions. The conventional HCT design was modified by changing the zeolite chemistry so as to improve HC retention coupled with more efficient combustion during the desorption phase. Increased trapping efficiently was achieved by
Lupescu, Jason, Xu, Lifeng, Nunan, John, Alltizer, Chad
A New Catalyzed HC Trap Technology that Enhances the Conversion of Gasoline Fuel Cold-Start Emissions2018-01-093804/03/2018
Passive in-line catalyzed hydrocarbon (HC) traps have been used by some manufacturers in the automotive industry to reduce regulated tailpipe (TP) emissions of non-methane organic gas (NMOG) during engine cold-start conditions. However, most NMOG molecules produced during gasoline combustion are only weakly adsorbed via physisorption onto the zeolites typically used in a HC trap. As a consequence, NMOG desorption occurs at low temperatures resulting in the use of very high platinum group metal (PGM) loadings in an effort to combust NMOG before it escapes from a HC trap. In the current study, a 2.0 L direct-injection (DI) Ford Focus running on gasoline fuel was evaluated with full useful life aftertreatment where the underbody converter was either a three-way catalyst (TWC) or a HC trap. A new HC trap technology developed by Ford and Umicore demonstrated reduced TP NMOG emissions of 50% over the TWC-only system without any increase in oxides of oxygen (NOx) emissions. Other HC trap
Lupescu, Jason, Xu, Lifeng, Jen, Hung-Wen, Harwell, Amy, Nunan, John, Alltizer, Chad, Denison, Gregory
Numerical Analysis of the Impact of Water Injection on Combustion and Thermodynamics in a Gasoline Engine Using Detailed Chemistry2018-01-020004/03/2018
Water injection is a promising technology to improve the fuel efficiency of turbocharged gasoline engines due to the possibility to suppress engine knock. Additionally, this technology is believed to enable the efficient operation of the three-way catalyst also at high-load conditions, through limiting the exhaust temperature. In this numerical study, we investigate the effect of water on the chemical and thermodynamic processes using 3D computational fluid dynamics (CFD) Reynolds-averaged Navier–Stokes (RANS) with detailed chemistry. In the first step, the influence of different amounts of water vapor on ignition delay time, laminar flame speed, and heat capacity is investigated. In the second step, the impact of water vaporization is analyzed for port and direct injection. For this purpose, the water mass flow and the injection pressure are varied. A steady-state, medium-speed, high-load engine operating point is investigated with focus on the effect of water injection on knock
Netzer, Corinna, Franken, Tim, Seidel, Lars, Lehtiniemi, Harry, Mauss, Fabian
Benefits of Pd Doped Zeolites for Cold Start HC/NOx Emission Reductions for Gasoline and E85 Fueled Vehicles2018-01-094804/03/2018
In the development of HC traps (HCT) for reducing vehicle cold start hydrocarbon (HC)/nitrogen oxide (NOx) emissions, zeolite-based adsorbent materials were studied as key components for the capture and release of the main gasoline-type HC/NOx species in the vehicle exhaust gas. Typical zeolite materials capture and release certain HC and NOx species at low temperatures (<200°C), which is lower than the light-off temperature of a typical three-way catalyst (TWC) (≥250°C). Therefore, a zeolite alone is not effective in enhancing cold start HC/NOx emission control. We have found that a small amount of Pd (<0.5 wt%) dispersed in the zeolite (i.e., BEA) can significantly increase the conversion efficiency of certain HC/NOx species by increasing their release temperature. Pd was also found to modify the adsorption process from pure physisorption to chemisorption and may have played a role in the transformation of the adsorbed HCs to higher molecular weight species. Both these processes led
Xu, Lifeng, Lupescu, Jason, Ura, Justin, Harwell, Amy, Paxton, William A., Nunan, John, Alltizer, Chad
Development of Highly Durable Zeolites as Hydrocarbon Trap Materials for Automotive Catalysts2018-01-094704/03/2018
Low-temperature activity is an important requirement for automotive catalysts. In particular, most of the tailpipe emissions occur right after the engine starts (cold emissions). These emissions can be effectively reduced by using a trap material such as zeolite for hydrocarbon (HC) adsorption [1, 2, 3, 4, 5, 6, 7, 8, 9]. However, using zeolite as a trap material in automotive catalyst is limited due to its low durability under hydrothermal aging conditions. That is the reason why zeolites can be often used for diesel engines which usually run at lower temperature than the gasoline engines during entire mode driving. In most cases, zeolites need to be placed away from large thermal loads in order to take advantage of their adsorption abilities. In general, the thermal endurance of close-coupled catalysts for gasoline powered vehicles proceeds at about 1000 °C in the presence of water. Under these conditions, the zeolite structure would be decomposed by the dissociation of aluminum from
Endo, Yoshinori, Nishikawa, Joe, Iwakura, Hironori, Inamura, Masaaki, Wakabayashi, Takashi, Nakahara, Yuunosuke, Ogasawara, Masataka, Kato, Sumio
Effects of NO X Storage Component on Ammonia Formation in TWC for Passive SCR NO X Control in Lean Gasoline Engines2018-01-094604/03/2018
A prototype three-way catalyst (TWC) with NOX storage component was evaluated for ammonia (NH3) generation on a 2.0-liter BMW lean burn gasoline direct injection engine as a component in a passive ammonia selective catalytic reduction (SCR) system. The passive NH3 SCR system is a potential approach for controlling nitrogen oxides (NOX) emissions from lean burn gasoline engines. In this 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, NOX passes through the TWC and is reduced by the stored NH3 on the SCR catalyst. Adding a NOX storage component to a TWC provides two benefits in the context of a passive SCR system: (1) enabling longer lean operation by storing NOX upstream and preserving NH3 inventory on the downstream SCR catalyst; and (2) increasing the quantity and rate of NH3 production during rich operation. Since the fuel penalty associated with passive SCR
Prikhodko, Vitaly, Pihl, Josh, Toops, Todd, Parks, James
Study of an Aftertreatment System for HLSI Lean-burn Engine2018-01-094504/03/2018
Lean-burn is an effective means of reducing CO2 emissions. To date, Homogenous Lean Charge Spark Ignition (HLSI) combustion, which lowers emissions of both CO2 and NOx, has been studied. Although HLSI realizes lower emission, it is a major challenge for lean-burn engines to meet SULEV regulations, so we have developed a new aftertreatment system for HLSI engines. It consists of three types of catalysts that have different functions, as well as special engine control methods. As the first stage in achieving SULEV emissions, this study focused on enhancing performance under lean conditions. HLSI engine exhaust gases contain high concentrations of hydrocarbons, including a large amount of paraffin, which are difficult to purify, rather than low concentrations of NOx. Therefore, the key point in low emissions is to purify not only NOx, but also high concentrations of paraffin at the same time. Other issues include maintaining high performance under stoichiometry operation and reducing N2O
Takeori, Hiroki, Wada, Katsuji, Matsuo, Yuichi, Morita, Tomoko, Konomoto, Takashi, Murata, Yuichiro, Kimura, Munekazu, Miyauchi, Atsuhiro
The Development of Low Temperature Three-Way Catalysts for High Efficiency Gasoline Engines of the Future: Part II2018-01-093904/03/2018
It is anticipated that future gasoline engines will have improved mechanical efficiency and consequently lower exhaust temperatures at low load conditions, although the exhaust temperatures at high load conditions are expected to remain the same or even increase due to the increasing use of downsized turbocharged engines. In 2014, a collaborative project was initiated at Ford Motor Company, Oak Ridge National Lab, and the University of Michigan to develop three-way catalysts with improved performance at low temperatures while maintaining the durability of current TWCs. This project is funded by the U.S. Department of Energy and is intended to show progress toward the USDRIVE target of 90% conversion of hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NOx) at 150 °C after high mileage aging. The testing protocols specified by the USDRIVE ACEC team for stoichiometric S-GDI engines were utilized during the evaluation of experimental catalysts at all three facilities. This
Theis, Joseph R., Getsoian, Andrew (Bean), Lambert, Christine K.
Numerical Optimization of the Combustion System of a HD Compression Ignition Engine Fueled with DME Considering Current and Future Emission Standards2018-01-024704/03/2018
A genetic algorithm (GA) optimization methodology is applied to the design of the combustion system of a heavy-duty (HD) Diesel engine fueled with dimethyl ether (DME). The study has two objectives, the optimization of a conventional diffusion-controlled combustion system aiming to achieve US2010 targets and the optimization of a stoichiometric combustion system coupled with a three way catalyst (TWC) to further control NOx emissions and achieve US2030 emission standards. These optimizations include the key combustion system related hardware, bowl geometry and injection nozzle design as input factors, together with the most relevant air management and injection settings. The GA was linked to the KIVA CFD code and an automated grid generation tool to perform a single-objective optimization. The target of the optimizations is to improve net indicated efficiency (NIE) while keeping NOx emissions, peak pressure and pressure rise rate under their corresponding target levels. Compared to the
Benajes, Jesus, Novella, Ricardo, Hernández-López, Alberto, Kokjohn, Sage
Cold-Start Hydrocarbon Speciation and Trap Materials for Gasoline Engines2018-01-094004/03/2018
Efficient hydrocarbon (HC) trap materials have been developed to trap the major emitting HC compounds from gasoline direct injection engines. Online FTIR measurements on different test cycles and catalytic systems showed that AHC, C5 compounds, and CH4 were the most emitted species at cold-start phase (up to 100 sec). Making AHC and C5 as targets for improving the HC light-off, lab scale reactor set-up was established with toluene and iso-pentane feed pumping system along with propane-propene mixture. TGA screening experiments conducted with ex-situ toluene adsorption and the results revealed that BEA type materials have moderate to higher HC trapping temperature and HC storage capacity. In the present investigation, BEA-HS exhibited outstanding stability and trapping ability even after 850 °C hydrothermal aging. PGM and TM based BEA materials were evaluated for HC-TPD experiments with TWC gas composition. Interestingly, adsorption properties of the samples at various aging
Narayana Rao, Komateedi, Kim, Mi-Young, Song, Jinwoo, Na, SeungChul, Han, Hyun Sik
Experimental and Kinetic Modeling of Degreened and Aged Three-way Catalysts: Aging Impact on Oxygen Storage Capacity and Catalyst Performance2018-01-095004/03/2018
The aging impact on oxygen storage capacity (OSC) and catalyst performance was investigated on one degreened and one aged (hydrothermally aged at 955 °C for 50 h) commercial three-way catalyst (TWC) by experiments and modeling. The difference of OSC between the degreened and aged TWCs was dependent on catalyst temperature. The largest difference was found at 600 °C, at which the amount of OSC decreased by 45.5%. Catalyst performance was evaluated through lightoff tests at two simulated engine exhaust conditions (lean and rich) on a micro-reactor. The aging impact on the catalyst performance was different under lean and rich environments and investigated separately. At the lean condition, oxidation of CO and C3H6 was significantly suppressed while oxidation of C3H8 was relatively less degraded. At the rich condition, the inhibition effect was more pronounced on the aged TWC and inhibiting hydrocarbon species from C3H6 partial oxidation can survive at temperatures up to 450 °C. However
Gong, Jian, Wang, Di, Li, Junhui, Kamasamudram, Krishna, Currier, Neal, Yezerets, Aleksey
Modelling the Variation in Precious Metal Dispersion in a Three Way Catalytic Converter after Aging2018-01-095904/03/2018
With emission legislations becoming ever more stringent, there is an increased pressure on after-treatment systems and more specifically three-way catalysts. With recent developments in emission legislations, there is a requirement for more complex after-treatment systems and understanding of the aging process. Whilst the body of understanding on catalyst deactivation and, in particular, catalyst aging is growing, there are still significant gaps in understanding, particularly how real world variations in temperature, flow rate and gas concentrations affect catalyst behavior. Under normal driving conditions, the catalyst can experience varying oxygen concentrations, such as under heavy acceleration or cruising down a hill will show a variation in oxygen from the engine emissions. The effect that varying oxygen concentrations has on the rate of aging is not fully understood and hence the total deactivation and conversion efficiencies are not known throughout the catalyst lifetime
Irwin, Kurtis, Douglas, Roy, Stewart, Jonathan David, Pedlow, Andrew, Woods, Andrew
Development of Three-Way Catalysts Enhanced NOx Purifying Activity2018-01-094204/03/2018
Growing concerns about the depletion of raw materials as vehicle ownership continues to increase is prompting automakers to look for ways of decreasing the use of platinum-group metals (PGMs) in the exhaust systems. This research has developed a new catalyst with strong robustness against fluctuations in the exhaust gas and excellent nitrogen oxide (NOx) conversion performance. One of the key technologies is a new OSC material that has low surface area (SA) and high OSC performance. We enhanced the pyrochlore- ceria/zirconia (CZ) which has a very small SA. In order to enhance the heat resistance and promote the OSC reaction, we selected and optimized the additive element. This material showed high OSC performance especially in the temperature range of 400 degrees or less. Another key technology is washcoat structure that has high gas diffusivity by making connected pore in the washcoat (New pore forming technology). The connected pore means that some pores are connected each other
Chinzei, Isao, Saito, Yoshinori, Morikawa, Akira, Kato, Satoru, Ohashi, Tatsuya, Hirao, Tetsuhiro
Impacts of Drive Cycle and Ambient Temperature on Modelled Gasoline Particulate Filter Soot Accumulation and Regeneration2018-01-094904/03/2018
Gasoline particulate filters (GPF) are used as an efficient solution to reduce particulate matter (PM) emissions on gasoline vehicles. GPFs are ceramic wall-flow filters and are normally located downstream of conventional three-way catalysts (TWC) [1]. The study in this paper is intended to evaluate the impact of drive cycle and ambient temperature on modelled GPF soot accumulation and regeneration. The test data were obtained through real road testing in Chinese cities including Nanjing, Hainan and Harbin. Five 2.0 L gasoline turbo direct-injection (GTDI) prototype vehicles from several China Stage 6 applications were employed for the road tests. The results of the testing indicated that a drive cycle with low engine speed and engine load, like a typical city road in rush hour traffic in Nanjing, had a low probability of generating high GPF temperatures (> 600 °C) and sufficient oxygen to regenerate the GPF. However, the soot accumulation model performed as expected [2] and the soot
Yue, Hongchao, Lehmen, Allen, Van Nieuwstadt, Michiel, Mason, Gregory, Barwick, Matt, Warm, David, Pebley, Kirk
Water Recovery from Gasoline Engine Exhaust for Water Injection2018-01-036904/03/2018
Water injection (WI) can improve gasoline engine performance and efficiency, and on-board water recovery technology could eliminate the need for customers to refill an on-board water reservoir. In this regard, the technical feasibility of exhaust water recovery (EWR) is described in this paper. Water injection testing was conducted at a full load condition (5000 rpm/18.1 bar BMEP) and a high load condition (3000 rpm/14.0 bar BMEP) on a turbocharged gasoline direction injection (GTDI) engine. Water recovery testing was conducted both after the exhaust gas recirculation (EGR) cooler and after the charge air cooler (CAC) at a high load (3000 rpm/14.0 bar BMEP), as well as a part load (2080 rpm/6.8 bar BMEP) condition, at temperatures ca. 10-15 °C below the dew point of the flow stream. Three types of water separation designs were tested: a passive cyclone separator (CS), a passive membrane separator (MEM), and an active separator (AS). Water injection and recovery amount was also
Sun, Yong, Fischer, Michael, Bradford, Michael, Kotrba, Adam, Randolph, Eric
Solid Particle Number and Ash Emissions from Heavy-Duty Natural Gas and Diesel w/SCRF Engines2018-01-036204/03/2018
Solid and metallic ash particle number (PN) and particulate matter (PM) mass emission measurements were performed on a heavy-duty (HD) on-highway diesel engine and a compressed natural gas (CNG) engine. Measurements were conducted under transient engine operation that included the FTP, WHTC and RMC. Both engines were calibrated to meet CARB ultra low NOX emission target of 0.02 g/hp-hr, a 90% reduction from current emissions limit. The HD diesel engine final exhaust configuration included a number of aftertreatement sub-systems in addition to a selective catalytic reduction filter (SCRF). The stoichiometric CNG engine final configuration included a closed coupled Three Way Catalyst (ccTWC) and an under floor TWC (ufTWC). The aftertreatment systems for both engines were aged for a full useful life (FUL) of 435,000 miles, prior to emissions testing. PM mass emissions from both engines were comparable and well below the US EPA emissions standard. However, the CNG engine emitted a
Khalek, Imad A., Badshah, Huzeifa, Premnath, Vinay, Brezny, Rasto
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