Browse Topic: Catalysts

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BALL BEARINGS.06000204/23/2025
HESS, HENRY
Investigation on Degradation Process of PdRuIr/CZ “Pseudo-Rh” Catalysts Used for Motorcycles2024-32-001604/18/2025
Platinum (Pt), palladium (Pd), and rhodium (Rh) are used as active substances in exhaust gas purification catalysts for automobiles. Among these, Rh is an essential element because it efficiently promotes a NOx reduction reaction. On the other hand, the price of Rh has been rising in recent years. From the perspective of the supply risk of rare resources, there is an urgent need to develop technologies to replace or reduce the amount of Rh used in catalysts. We focused on the pseudo-rhodium alloy developed by the ACCEL program of the Japan Science and Technology Agency (JST), and then investigated the application of the pseudo-rhodium alloy on the catalysts of our motorcycles and also the degradation process. A nanosized PdRuIr alloy supported on a ceria-zirconia solid solution (PdRuIr/CZ) was prepared and assembled into a motorcycle for emissions measurement. The PdRuIr/CZ catalyst with an alloy loading of 4.0 g/L had initial properties comparable to the Rh supported on a CZ (Rh/CZ
Motegi, Takuya, Tatara, Shunya, Takamoto, Shunpei, Doi, Kosuke
Desensorization: A Novel Method for Urea Concentration Deterioration Detection in BSVI Engines2024-26-015401/16/2024
Urea concentration deterioration detection in BSVI engines is vital for maintaining compliance with emission regulations. This paper introduces a groundbreaking desensorization method, which offers numerous benefits in detecting urea concentration deterioration by estimating the drop in catalyst conversion efficiency. Traditionally, urea quality sensors have been employed to measure the absolute concentration of urea in the aqueous solution (Diesel Exhaust Fluid – DEF). This information is used to detect usage of poor quality DEF. However, desensorization eliminates the need for dedicated sensors, reducing complexity, cost, and potential sensor-related errors. The proposed method leverages the strong relationship between catalyst conversion efficiency and urea concentration. By monitoring catalyst inlet and outlet NOx values using NOx sensors, the efficiency of the catalyst can be estimated. This estimation allows for the detection of urea concentration deterioration, ensuring that NOx
Venkat, Harish, Kumar, Gokul Elumalai, Kumar, Kosalaraman, G, Vijayakumar
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
Tubing Coated with Light-Powered Catalysts Aids Drug ManufacturingTBMG-4694811/01/2022
OSC modelling of 3-way automotive catalysts to understand the effect of latent OSC on dynamic OSC performance2022-01-069303/29/2022
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. OSC in 3-way automotive catalysts can be split into two main OSC types. "Latent OSC" deep within the layers of the washcoat and "dynamic" OSC on the surface layers of the catalyst washcoat. Dynamic OSC is more commonly applied in the evaluation of the activity of the catalyst during practical operation. This paper uses a kinetic OSC model with a layered washcoat approach to analyse OSC test data and show how latent OSC can affect the dynamic OSC performance of a 3-way catalyst. Model
Mc Grane, Liam, Douglas, Roy, Elliott, Matthew, Irwin, Kurtis, Woods, Andrew, Pedlow, Andrew
Development of ceramic EHC2022-01-065103/29/2022
In recent years, electrically heated catalysts (EHCs) have been developed to reduce emissions. Among several types of heating methods of EHCs, the direct heating method, in which a current is applied to the catalyst substrate directly, makes it easy to activate the catalyst before starting the engine. The research results that emissions (HC + NOx) were reduced 76% with the direct heating EHC have been reported. In terms of catalyst support, ceramics are considered to be a better material for the substrate than metal due to the coefficient of linear thermal expansion difference between the wash coat and the substrate. However, EHCs made of ceramics have issues such as controllability of the current distribution and durability reliability of the connection between the substrate and the electrodes. This paper reports about the hardware configuration of the direct heating EHC made of ceramics, including the catalytic substrate as an electric circuit, its electrode, and the insulation
Sadamitsu, Takahiro, Oki, Toshinori, Korenaga, Shingo, Hirooka, Shigemasa, Iwasaki, Shingo, Iida, Tatsuo
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
Extending NREL's FASTSim to model catalyst transient warmup behavior2022-01-057803/29/2022
A custom version of NREL's FASTSim was extended to include transient thermal models for engine and catalysts with the goal of understanding catalyst warmup dynamics during cold start for light duty vehicles representing a range of vehicle sizes, makes, and models, including a small sedan and multiple SUV or truck body types. The model was calibrated and separately validated for various each vehicle using dynamometer test data conducted over various regulatory drive cycles and a sweep of ambient and initial conditions ranging from -20°C to 40°C. The NSGA-II multi-objective-optimization algorithm in Python's PyMOO package was used to select calibration parameters to identify the Pareto minimal hyper-surface of time-weighted engine temperature, catalyst temperature, and fueling errors for each test data set. By scaling component parameters with respect to engine peak power, the model was then exercised over a nationally representative range of initial temperatures, ambient temperatures
Baker, Chad
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
Prediction of Biodiesel Production from Sardine Fish Oil Methyl Ester Using Microwave Assisted Transesterification Method Using Response Surface Methodology2021-01-120209/21/2021
This study presents a demonstration of generating biodiesel from fish oil utilising microwave with a significant reduction in the amount of catalyst needed during the reaction and the time of reaction. Various factors such as microwave power, catalyst concentration, reaction duration, and molar ratio were tested experimentally. The response surface approach was used to improve the reaction parameters. As reaction parameters, four levels were chosen: molar ratio, catalyst concentration, and reaction time. According to the RSM model results, molar ratio has a crucial role in the transesterification of fish oil to bio diesel. Confirmatory tests were carried out to validate the acquired data, and they proved to be worthwhile.
Sathyamurthy, Ravishankar, CHANDRA SEKHAR, S., Venkatesan PhD, M
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
Method Recovers Metals from Electronic WasteTBMG-3959108/01/2021
Inspired by nature’s work to build spiky structures in caves, engineers have developed a method to recover precious metals from electronic waste. Using controlled applications of oxygen and relatively low temperatures, the engineers say they can de-alloy a metal by slowly moving the most reactive components to the surface, where they form stalagmitelike spikes of metal oxides. That leaves the least-reactive components in a purified, liquid core surrounded by brittle metal-oxide spikes.
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
Creation of OBD Limit Motorcycle Catalysts Using Different Ageing Methods2021-01-059804/06/2021
This paper outlines a novel method employed to accurately age catalysts to the required OBD limit for European motorcycles legalisation Euro 5 using a combination of modelling and testing. The method applies several strategies, including thermal ageing and catalyst poisoning, to reduce catalyst activity in order to mirror real-world catalyst ageing. Predictions were made using a combined global and micro kinetic model to specify catalyst activity to a matching light-off condition. The model simulated a motorcycle operating on a WMTC (World Motorcycle Test Cycle) and adjusted catalyst activity (Precious metal and Oxygen Storage Capacity) until tailpipe emissions matched the limits for Euro 5 OBD II. The same model ran a simulated light-off test to predict the light-off point for the catalyst. The catalyst was then aged to match this light-off performance using a RAT ageing cycle with additional poisoning to reach the target deactivation. Performance was checked at interim points to
Mc Grane, Liam, Douglas, Roy, Irwin, Kurtis, Pedlow, Andrew, Stewart, Jonathan, Woods, Andrew, Muehlstaedt, Fabian
Case Study of Diesel Catalyst Performance Sensitivity and Degradation due to Alkali Metal Poisoning from Suspicious Use of Unregulated Fuel2021-01-061404/06/2021
Advances in diesel engine and catalyst technologies have enabled light passenger vehicles in meeting the most stringent Tier 3/LEV III emission levels and durability requirements. The advancements in diesel aftertreatment catalyst technology have made catalysts more susceptible to low levels of impurities, typically referred to as poisons. Published studies over the last two decades, have shown a significant impact on the performance of catalysts, to the presence of sulfur and other inorganics in fuels and oils. The design of an aftertreatment system (ATS) typically sets limits for lubricant and fuel quality, specific to the geographical region and availability of certain level of regulated fuels. In this study, we investigate a real-world aged diesel vehicle which exhibited deterioration in tailpipe emissions, beyond levels targeted during engineering development. A root cause investigation measured deterioration, revealed that the catalysts were exposed to high levels of sodium (Na
Ahari, Homayoun, Andra, Ramesh, Pauly, Thomas
An Investigation of Emission Species over a Diesel Oxidation Catalyst Using Flow Reversal Strategy2021-01-060604/06/2021
With the increasing demand of emission reductions from the automotive industry, advanced after-treatment strategies have been investigated to overcome the challenges associated with meeting increasingly stringent emission regulations. Ongoing investigations on low temperature combustion (LTC) strategies are being researched to meet future emission regulations, however, the lowered exhaust temperature presents an even greater issue for exhaust after-treatment due to the change in combustion modes. Catalyst temperature is critical for the catalytic ability to maintain effective conversion efficiency of regulated emissions. The use of periodic flow reversal has shown benefits of maintaining catalyst temperature by alternating the exhaust flow direction through the catalytic converter, reducing the catalyst sensitivity to inlet gas temperature fluctuations. Cyclically alternating the exhaust flow direction can produce a thermal wave, elevating the central catalyst temperature above the
Hesketh, Cavan, Liang, Li, Sandhu, Navjot Singh, Han, Xiaoye, Wang, Meiping, Zheng, Ming
Investigating the Effect of Water and Oxygen Distributions on Consistency of Current Density Using a Quasi-Three-Dimensional Model of a PEM Fuel Cell2021-01-073704/06/2021
Activation loss, mass transfer loss and ohmic loss are the three main voltage losses of the polymer electrolyte membrane fuel cell. While the former two types are relevant to concentration of oxygen in catalyst layer and the later one is associated with the water content in membrane. Distributions of water content and oxygen in a single cell are inconsistent which cause that current densities in each segment of the single cell are different. For the dry inlet gas, the water in the segments near the gas inlet channel will be carried to the segments near the gas outlet channel, which causes high ohmic loss of the segments near the gas inlet channel. In this work, a transfer non-isothermal quasi-three-dimensional model is developed to investigate inconsistency of current densities. Comprehensive physical and chemical phenomena inside the cell are included, especially the mass transfer of hydrogen, oxygen, vapor and liquid water in gas channels, gas diffusion layer and catalyst layer and
Wang, Xuhui, Lu, Yikang, Zhang, Baitao, Xu, Sichuan
Development of High-Performance FC Stack for the New MIRAI2021-01-074004/06/2021
The first MIRAI was launched in 2014 as the world’s first commercial fuel cell vehicle (FCV) [1]. Compared to the FC stack used in the first MIRAI, the FC stack in the new MIRAI achieved one of the highest volumetric power densities in the world (5.4 kW/L, excluding end plates, 1.5 times higher than the FC stack in the first MIRAI) by adopting a new flow channel for the bipolar plate and an improved electrode [2]. Enhancing the current density is an important means of increasing power performance and reducing size. The bipolar plate functions to distribute gas and drain water inside the cells to stabilize current generation. However, a conventional straight flow channel tends to cause flooding, which makes it difficult to maintain stable current generation. A partially narrow flow channel was developed to enhance oxygen diffusion without the 3D fine-mesh flow field that was adopted in the previous FC stack. With this new technology, the oxygen concentration in the catalyst layer is 2.3
Yoshizumi, Tomoo, Kubo, Hideki, Okumura, Masao
A Study of the Effect of Light-Off Temperatures and Light-Off Curve Shape on the Cumulative Emissions Performance of 3-Way Catalytic Converters2021-01-059404/06/2021
The results of this paper will show the reader how to quantify a minimum light-off temperature to meet the required emissions standards with the use of a 3-way catalytic converter. The method can be applied to both motorcycle and larger automotive catalysts to help meet their respective emissions standards (Euro 5/Euro 7). The ability to predict a light-off temperature for any catalyst at the beginning of the project saves both time and resource. With an emphasis on how the shape of the light-off curve affects the cumulative tailpipe emissions and how shape of the light-off curves change with the ageing process. Changes in the light-off curves will be reviewed to understand how the chemical reactions and pore diffusion mechanisms within the catalyst deplete to negatively affect performance over its life time. Using the total cumulative emissions target to achieve the OBD (On Board diagnostic) requirement along with WMTC data, light-off curves were modelled using predicted catalyst
Mc Grane, Liam, Douglas, Roy, Irwin, Kurtis, Stewart, Jonathan, Woods, Andrew, Muehlstaedt, Fabian
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
Sunlight Converts Emissions into Useful MaterialsTBMG-3800511/01/2020
The rapidly growing concentration of carbon dioxide (CO2) in the Earth’s atmosphere is one of the most urgent issues humanity must address to avoid a climate catastrophe. Thanks to greenhouse gases like CO2, the heat from the Sun is remaining trapped in the atmosphere, warming the planet. Researchers developed a method to break CO2 apart and convert the greenhouse gas into useful materials like fuels or consumer products ranging from pharmaceuticals to polymers.
Reaction Path Analysis and Modeling of NOx Reduction in a Cu-chabazite SCR Catalyst Considering Cu Redox Chemistry and Reversible Hydrolysis of Cu Sites2020-01-218109/15/2020
In this study, reaction path analysis and modeling of NOx reduction phenomena by selective catalytic reduction (SCR) with NH3 over a Cu-chabazite catalyst were conducted considering changes in the valence state of Cu sites and local structure due to differences in ligands to the Cu sites. The analysis showed that in the Cu-chabazite catalyst, NOx was mainly reduced by adsorbed NH3 on divalent Cu sites accompanied by a change in valence state of Cu from divalent to monovalent. It is known that the activation energy of NOx reduction on a Cu-chabazite catalyst changes between low temperatures ≤ 200 °C and mid to high temperatures ≥ 300 °C. To express this phenomenon, a reversible hydrolysis reaction based on the difference in coordination state of hydroxyl groups (OH−) to Cu sites at low and high temperatures was introduced into the model. The results showed that NOx reduction phenomena can be expressed over a wide temperature range by using the activation energy specific to the Cu
Tsukamoto, Yoshihisa, Ueyama, Rikuto, Ogawa, Kenya, Seki, Keiichiro, Kunisu, Masahiro, Fukuma, Takao, Kusaka, Jin
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
Hybrid Modeling of a Catalyst with Autoencoder Based Selection Strategy2020-01-217809/15/2020
Two substantially different methods have become popular in building fast computing catalyst models: physico-chemical approaches focusing on dimensionality reduction and machine learning approaches. Data driven models are known to be very fast computing and to achieve high accuracy but they can lack of extrapolation capability. Physico-chemical models are usually slower and less accurate but superior regarding robustness. The robustness can even be reinforced by implementing an extended Kalman filter, which enables the model to adapt its states based on actual sensor values, even if the sensors are drifting. The present study proposes a combination of both approaches into one hybrid model, keeping the robustness of the physico-chemical model in edge cases while also achieving the accuracy of the data based model in well-known regimes. The output of the hybrid model is controlled by an autoencoder, utilizing methods well known from the field of anomaly detection. It was validated that
Kühne, Joana, März, Christian, Werfel, Johannes, Gelbert, Gregor, Behrendt, Frank, Guehmann, Clemens
An Experimental Facility for Rapid Testing of SCR Systems2020-01-219209/15/2020
Urea-SCR (selective catalytic reduction) has become the principal technology used to lower NOx emissions in automotive compression ignition engines. Although the technology is well known and developed, the stricter emissions’ limits force engineers to implement new approaches to reduce warm-up time and improve the mixing process of the urea-water solution with the exhaust gases while avoiding a solid deposit formation. The exhaust system’s design is optimized using 3D numerical methods, but the validation of the design’s performance requires prototype testing on an engine dynamometer, where it is difficult to decouple and adjust the exhaust gas composition and temperature as in the numerical model; and thus it is problematic to verify the model. In this study we propose an experimental facility for rapid testing of SCR systems in simulated and precisely controlled engine-relevant conditions. The experimental set-up presented here uses heated atmospheric air with an addition of nitrogen
Boruc, Łukasz, Rogoz, Rafał, Bachanek, Jakub, Kapusta, Łukasz Jan, Jaworski, Piotr, Sutkowski, Marek, Teodorczyk, Andrzej, Jarosinski, Sebastian
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
The Influence of Reduxco Catalyst in the Diesel Fuel on Energy Parameters, Exhaust Gas Composition and Rate of Heat Release of a Diesel Engine2020-01-206109/15/2020
According to the information provided by the catalyst producer, the catalyst with the trade name Reduxco, which was used in the research, is a reaction product of acetic acid, iron, n-butanol, n-propanol and isopropanol. According to Customer data, Reduxco catalyst in a fuel causes a decrease of the energy of activation of the hydrocarbon fuel oxidation reaction, introduces additional OH groups allowing to increase the burning rate, facilitates the combustion of already formed solid particles in the engine cylinder. To confirm this information, comparative tests were carried out (in the Internal Combustion Engines laboratory of the Cracow University of Technology); the analysis included not only the energy parameters and exhaust gas composition of the diesel engine powered by standard diesel oil and Reduxco-containing fuel, but also the indicator charts and rate of heat release in the engine cylinder. What was used in the tests was a turbocharged VW 1.9 TDI diesel engine, which was
Cisek, Jerzy, Lesniak, Szymon, Mokretskyy, Vitaliy, Przybylski, Włodzimierz
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
Hydrogen Selective Catalytic Reduction of Nitrogen Oxide on Pt- and Pd-Based Catalysts for Lean-Burn Automobile Applications2020-01-217309/15/2020
The utilization of H2 to catalytically treat NO emissions under lean-burn engine exhaust conditions was studied on Pt- and Pd-containing catalysts supported on CeO2 and MgO. The catalytic performance was examined using a fixed-bed reactor whose dry effluent gas stream was analyzed by an online FTIR analyzer. The catalysts NO conversion and N2 selectivity were measured in the range of 125-3000C with a feed gas composition of 0.05%NO/1%H2/10%O2/N2. The CeO2-based catalysts exhibited higher NO conversion, and the most effective catalyst was Pd/CeO2, with a conversion of 67% and selectivity of 70% near 2300C. The prepared solids were characterized using different techniques (BET, ICP-OES, CO pulse chemisorption, STEM, EELS and EDS) to correlate the structural and morphological properties of the metallic phase and the support with the catalytic activity. CeO2 is a more effective support as it yields higher metal dispersion and better facilitates the reduction of the Pt and Pd catalysts.
Alghamdi, Nawaf M., Restrepo Cano, Juan, Anjum, Dalaver H., Im, Hong G., Kalamaras, Christos, Gascon, Jorge, Sarathy, S. Mani
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
Numerical Optimization of a SCR System Based on the Injection of Pure Gaseous Ammonia for the NOx Reduction in Light-Duty Diesel Engines2020-01-035604/14/2020
Selective Catalytic Reduction (SCR) systems are nowadays widely applied for the reduction of NOx emitted from Diesel engines. The typical process is based on the injection of aqueous urea in the exhaust gases before the SCR catalyst, which determines the production of the ammonia needed for the catalytic reduction of NOx. However, this technology is affected by two main limitations: a) the evaporation of the urea water solution (UWS) requires a sufficiently high temperature of the exhaust gases and b) the formation of solid deposits during the UWS evaporation is a frequent phenomenon which compromise the correct operation of the system. In this context, to overcome these issues, a technology based on the injection of gaseous ammonia has been recently proposed: in this case, ammonia is stored at the solid state in a cartridge containing a Strontium Chloride salt and it is desorbed by means of electrical heating. In this work, an after-treatment system based on the injection of gaseous
Della Torre, Augusto, Montenegro, Gianluca, Onorati, Angelo, Cerri, Tarcisio, Tronconi, Enrico, Nova, Isabella
Deep Optimization of Catalyst Layer Composition via Data-Driven Machine Learning Approach2020-01-085904/14/2020
Proton exchange membrane fuel cell (PEMFC) provides a promising future low carbon automotive powertrain solution. The catalyst layer (CL) is its core component which directly influences the output performance. PEMFC performance can be greatly improved by the effective optimization of CL composition. This work demonstrates a deep optimization of CL composition for improving the PEMFC performance, including the platinum (Pt) loading, Pt percentage of carbon-supported Pt and ionomer to carbon ratio of the anode and the cathode,. The simulation results by a PEMFC three-dimensional (3D) computation fluid dynamics (CFD) model coupled with the CL agglomerate model is used to train the artificial neural network (ANN) which can efficiently predict the current density under different CL composition. Squared correlation coefficient (R-square) and mean percentage error in the training set and validation set are 0.9867, 0.2635% and 0.9543, 1.1275%, respectively. It illustrates that the well-trained
Wang, Bowen, Xie, Biao, Xuan, Jin, Gu, Wen, Zhao, Dezong, Jiao, Kui
Ammonia Measurement Investigation Using Quantum Cascade Laser and Two Different Fourier Transform Infrared Spectroscopy Methods2020-01-036504/14/2020
Most diesel engine exhausts have been fitted with SCR (Selective Catalyst Reduction) in order to reduce NOX (Oxides of Nitrogen) by using NH3 (ammonia). However, both NOX and NH3 have been classified as compounds hazardous for the environment and human health. If the reaction between NOX and NH3 is unbalanced during treatment, it can lead to either NOX or NH3 being released into the environment. Accurate measurement is thus necessary. QCL (Quantum Cascade Laser) and FTIR (Fourier Transform InfraRed) are two methods that have been used to measure NH3 and NOX directly in diesel engine exhausts. However, only a few studies have compared those two methods of NH3 measurement, mainly from diesel engine exhausts. The aim of this paper is to compare the QCL and 2 different FTIR specifications for NH3 measurement directly from diesel engine exhausts under well-controlled laboratory conditions. Researchers have found that as NH3 is reactive, it is absorbed inside the exhaust pipe if the probe
Li, Nilton, El-Hamalawi, Ashraf, Barrett, Richard, Baxter, Jim
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
Relevance of Exhaust Aftertreatment System Degradation for EU7 Gasoline Engine Applications2020-01-038204/14/2020
Exhaust aftertreatment systems must function sufficiently over the full useful life of a vehicle. In Europe this is currently defined as 160.000 km. With the introduction of Euro 7 it is expected that the required mileage will be extended to 240.000 km. This will then be consistent with the US legislation. In order to quantify the emission impact of exhaust system degradation, an Euro 7 exhaust aftertreatment system is aged by different accelerated approaches: application of the Standard Bench Cycle, the ZDAKW cycle, a novel ash loading method and borderline aging. The results depict the impact of oil ash on the oxygen storage capacity. For tailpipe emissions, the maximum peak temperatures are the dominant aging factor. The cold start performance is effected by both, thermal degradation and ash accumulation. An evaluation of this emission increase requires appropriate benchmarks. For this purpose, an analysis of the emission impacts of ambient temperatures, driving modes and
Sterlepper, Stefan, Claßen, Johannes, Pischinger, Stefan, Görgen, Michael, Cox, Jim, Nijs, Martin, Scharf, Johannes
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
3D-Printed Liquid Lab-on-a-ChipTBMG-3527910/01/2019
Researchers have 3D-printed an all-liquid device that, with the click of a button, can be repeatedly reconfigured on demand to serve a wide range of applications from making battery materials to screening drug candidates.
Graphene Lid Extends Photoemission Electron Microscopy to LiquidsTBMG-3475307/01/2019
By capping liquids with graphene (an ultrathin sheet of pure carbon), researchers can easily image and analyze liquid interfaces and the surface of nanometer-scale objects immersed in liquids. In the imaging technique known as photoemission electron microscopy (PEEM), ultraviolet light or X-rays bombard a sample, stimulating the material to release electrons from a region at or just beneath its surface. Electric fields act as lenses, focusing the emitted electrons to create an image.
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
Scientists 3D Print All-Liquid ‘Lab on a Chip’TBMG-3455206/01/2019
Researchers at DOE's Lawrence Berkeley National Laboratory (Berkeley Lab) have 3D printed an all-liquid device that, with the click of a button, can be repeatedly reconfigured on demand to serve a wide range of applications — from making battery materials to screening drug candidates.
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