Browse Topic: Catalysts

Items (3,420)

Development of a Non-Catalytic JP-8 Reformer

2024-01-3708

11/15/2024

ABSTRACT Advanced Cooling Technologies, Inc. (ACT) has been developing a Swiss-roll type, non-catalytic, thermal partial oxidation JP-8 reformer. The principle is using effective heat recirculation to increase the partial oxidation reaction temperature, which maximizes the H2 and CO yield without using catalyst. The gas phase reaction eliminates catalyst-associated issues, such as poisoning, coking, degradation, etc. Since the process uses only air and JP-8 fuel as the reactants, and is self-sustained (no external energy input), minimum balance-of-plant is required. One challenge of this reforming technology is the “out-of-center” reaction. Due to being highly preheated, the fuel and air mixture from the inlet is auto-ignited before entering the designed center reaction zone. The out-of-center reaction causes low reforming efficiency and potentially damages the inlet channel walls. In the previous study, direct injection of JP-8 fuel into the center reaction zone is able to avoid the

Chen, Chien-Hua, Crawmer, Joel, Richard, Brad, Pearlman, Howard, Ronney, Paul

Experimental and Numerical Investigations on the Effect of Urea Pulse Injection Strategies to Reduce NOx Emission in Urea-SCR Catalysts

2024-01-4304

11/05/2024

A major challenge for auto industries is reducing NOx and other exhaust gas emissions to meet stringent Euro 7 emission regulations. A urea Selective Catalyst Reduction (SCR) after-treatment system (ATS) commonly uses upstream urea water injection to reduce NOx from the engine exhaust gas. The NOx emission conversion rate in ATSs is high for high exhaust gas temperatures but substantially low for temperatures below 200°C. This study aims to improve the NOx conversion rate using urea pulse injection in a mass-production 2.2 L diesel engine equipped with an SCR ATS operated under low exhaust gas temperature. The engine experimental results show that, under 200°C exhaust temperature and 3.73x104 h-1 gross hourly space velocity (SV), the NOx conversion rate can be improved by 5% using 5-sec ON and 12-sec OFF (denoted as 5/12 s) urea pulse supply compared to the constant supply under time-averaged 1.0 urea equivalence ratio. It is experimentally observed that the urea pulse supply’s

Yoshida, Fuka, Takahashi, Hideaki, Kotani, Yuya, Zu, Qiuyue, Sok, Ratnak, Kusaka, Jin

Effects of Fuel Distillation Characteristics on the Performance of Catalyst-Heating Operation in a Medium-Duty Off-Road Diesel Engine

2024-01-4278

11/05/2024

Catalyst heating operation in compression-ignition engines is critical to ensure rapid light-off of exhaust catalysts during cold-start. This is typically achieved by using late post injections for increased exhaust enthalpy, which retardability is constrained by acceptable CO and unburned hydrocarbons emissions, since they are directly emitted through the tailpipe due to the inactivity of the oxidation catalyst at these conditions. Post-injection retardability has shown to be affected by the cetane number of the fuel, but it is unclear how other fuel properties affect the ability to retard the combustion. This study aims to understand the impact of the distillation characteristics of the fuel on the performance of catalyst heating operation and on post-injection retardability. In this study, experiments are performed in a single-cylinder medium-duty diesel engine fueled with three full boiling-range diesel fuels with different distillation curves using a five-injection strategy (two

Lee, Sanguk, Lopez Pintor, Dario, Cho, Seokwon, Busch, Stephen

Catalyzed Gasoline Particulate Filter Performance from Fresh to Full Useful Life

2024-01-4311

11/05/2024

The gasoline particulate filter (GPF) represents a durable solution for particulate emissions control in light-duty gasoline-fueled vehicles. It is also seen as a viable technology in North America to meet the upcoming US EPA tailpipe emission regulation, the proposed “Multipollutant Rule for Model Year 2027”. The goal of this study was to track the evolution of tailpipe particulate emissions of a modern GTDI light duty vehicle under typical North American mileage accumulation; from a fresh state to 4000-mile, and finally to its full useful life of 150,000-miles. For this purpose, a production TWC + GPF after-treatment system was installed in place of the T3B85 TWC-only system. Chassis dyno emissions testing was performed at the pre-determined mileage points with on-road driving conducted for the necessary mileage accumulation. This report will show the outstanding filtration durability and enhanced particulate control and of the current GPF technology all the way to 150,000 miles for

Craig, Angus, Warkins, Jason, Beattie, James, Nipunage, Sanket, Moser, David, Day, Ryan, Banker, Vonda

Emission Optimization of the Cold Start Behavior of a CNG Engine with Electrically Heated Catalyst and Secondary Air Injection

2024-24-0028

09/18/2024

Decarbonization and a continuous reduction in exhaust emissions from combustion engines are key objectives in the further development of modern powertrains. In order to address both aspects, the DE4LoRa research project is developing an innovative hybrid powertrain that is characterized by the highly flexible combination of two electric motors with a monovalent compressed natural gas (CNG) engine. This approach enables highly efficient driving in purely electric, parallel and serial operating modes. The use of synthetic CNG alone leads to a significant reduction in CO2 emissions and thus in the climate impact of the drivetrain. With CNG-powered engines in particular, however, methane and other tailpipe emissions of climate gases and pollutants must also be minimized. This is possible in particular through efficient exhaust gas aftertreatment and an effective operating strategy of the powertrain. This publication presents measurement results that examine the critical aspect of cold

Noone, Patrick, Herold, Tim, Beidl, Christian

Numerical Study of Catalytic Methanation Reactions Using a Kinetic Model

2024-24-0022

09/18/2024

Even if huge efforts are made to push alternative mobility concepts, such as, electric cars (BEV) and fuel cell powered cars, the importance and use of liquid fuels is anticipated to stay high during the 2030s. The biomethane and synthetic natural gas (SNG) might play a major role in this context as they are raw material for chemical industry, easy to be stored via existing infrastructure, easy to distribute via existing infrastructure, and versatile energy carrier for power generation and mobile applications. Hence, biomethane and synthetic natural gas might play a major role as they are suitable for power generation as well as for mobile applications and can replace natural gas without any infrastructure changes. In this paper, we aim to understand the direct production of synthetic natural gas from CO2 and H2 in a Sabatier process based on a thermodynamic analysis as well as a multi-step kinetic approach. For this purpose, we thoroughly discuss CO2 methanation to control emission in

Mauss, Fabian

TOC

99-06-03-0TOC

06/21/2024

TOC

Tobolski, Sue

Model-Based Algorithm for Water Management Diagnosis and Control of PEMFC Systems for Motive Applications

2024-37-0004

06/12/2024

Water management in PEMFC power generation systems is a key point to guarantee optimal performances and durability. It is known that a poor water management has a direct impact on PEMFC voltage, both in drying and flooding conditions: furthermore, water management entails phenomena from micro-scale, i.e., formation and water transport within membrane, to meso-scale, i.e., water capillary transport inside the GDL, up to the macro-scale, i.e., water droplet formation and removal from the GFC. Water transport mechanisms through the membrane are well known in literature, but typically a high computational burden is requested for their proper simulation. To deal with this issue, the authors have developed an analytical model for the water membrane content simulation as function of stack temperature and current density, for fast on-board monitoring and control purposes, with good fit with literature data. The water flow from the catalyst layer to the GFC through the GDL is modelled

Sicilia, Massimo, Cervone, Davide, Polverino, Pierpaolo, Pianese, Cesare

Effect of Dithering on Post-Catalyst Exhaust Gas Composition and on Short Time Regeneration of Deactivated PdO/Al ₂ O ₃ Catalysts under Real Engine Conditions

2024-37-0002

06/12/2024

Fossil fuels such as natural gas used in engines still play an important role worldwide which however is also exacerbating climate change as a result of carbon dioxide emissions. Although natural gas engines show an overall low pollutant emissions level, methane slip due to incomplete combustion occurs, causing methane emissions with a more than 20 times higher global warming potential than CO2. Additionally, further tightening of emissions legislation is to be expected bringing methane emissions even more into focus making exhaust gas aftertreatment issues remain relevant. For lean gas applications, (Pd)-based catalysts turned out to convert CH4 most efficiently usually being supported by metal oxides such as aluminium oxide (Al2O3). Water (H2O) contained in the exhaust gas causes strong inhibition on Pd catalysts. In real exhaust gases, not only water vapour but also pollutants and sulphur-containing compounds such as hydrogen sulphide (H2S) or sulphur oxides (SOx) are poisoning the

Tomin, Sebastian, Wagner, Uwe, Koch, Thomas

Converting Carbon Dioxide to Solid Carbon Nanofibers

TBMG-50650

05/01/2024

Researchers at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory and Columbia University have developed a way to convert carbon dioxide (CO2), a potent greenhouse gas, into carbon nanofibers, materials with a wide range of unique properties and many potential long-term uses. Their strategy uses tandem electrochemical and thermochemical reactions run at relatively low temperatures and ambient pressure. As the scientists describe in the journal Nature Catalysis, this approach could successfully lock carbon away in a useful solid form to offset or even achieve negative carbon emissions

Emergence of Quantum Computing Technologies in Automotive Applications: Opportunities and Future Use Cases

EPR2024008

04/22/2024

Quantum computing and its applications are emerging rapidly, driving excitement and extensive interest across all industry sectors, from finance to pharmaceuticals. The automotive industry is no different. Quantum computing can bring significant advantages to the way we commute, whether through the development of new materials and catalysts using quantum chemistry or improved route optimization. Quantum computing may be as important as the invention of driverless vehicles. Emergence of Quantum Computing Technologies in Automotive Applications: Opportunities and Future Use Cases attempts to explain quantum technology and its various advantages for the automotive industry. While many of the applications presented are still nascent, they may become mainstream in a decade or so. Click here to access the full SAE EDGETM Research Report portfolio

Kolodziejczyk, Bart

Post-Oxidation Phenomena as a Thermal Management Strategy for Automotive After-Treatment Systems: Assessment by Means of 3D-CFD Virtual Developmen t

2024-01-2629

04/09/2024

The target of the upcoming automotive emission regulations is to promote a fast transition to near-zero emission vehicles. As such, the range of ambient and operating conditions tested in the homologation cycles is broadening. In this context, the proposed work aims to thoroughly investigate the potential of post-oxidation phenomena in reducing the light-off time of a conventional three-way catalyst. The study is carried out on a turbocharged four-cylinder gasoline engine by means of experimental and numerical activities. Post oxidation is achieved through the oxidation of unburned fuel in the exhaust line, exploiting a rich combustion and a secondary air injection dedicated strategy. The CFD methodology consists of two different approaches: the former relies on a full-engine mesh, the latter on a detailed analysis of the chemical reactions occurring in the exhaust line. The coupling between experimental data and simulation results provides a complete assessment of the investigated

Barillari, Loris, Pipolo, Mario, Della Torre, Augusto, Montenegro, Gianluca, Onorati, Angelo, Vacca, Antonino, Chiodi, Marco, Kulzer, André

Improved Coated Gasoline Particulate Filters for China 7 and US Tier 4 Legislations

2024-01-2387

04/09/2024

The impending emission regulations in both China (CN7) and the United States (Tier 4) are set to impose more stringent emission limits on hydrocarbons (HC), carbon monoxide (CO), nitrogen oxides (NOx), and particulate matter (PM). CN7 places particular emphasis on reducing particulate number (PN) thresholds, while the forthcoming United States Tier 4 legislation is primarily concerned with reducing the allowable particulate matter (PM) to an assumed limit of 0.5 mg/mile. Given the more stringent constraints on both PN and PM emissions, the development of enhanced aftertreatment solutions becomes imperative to comply with these new regulatory demands. Coated Gasoline Particulate Filters (cGPFs) play a pivotal role as essential components for effective PN and PM abatement. These filters are typically deployed in one of two configurations: close-coupled to the turbocharger positioned downstream of a primary three-way catalyst (TWC) or located further downstream of the exhaust system in an

Schoenhaber, Jan, Kawashima, Shota, Gotthardt, Meike, Schühle, Johannes

Methane Conversion in Stoichiometric Natural Gas Engine Exhaust

2024-01-2632

04/09/2024

Stoichiometric natural gas (CNG) engines are an attractive solution for heavy-duty vehicles considering their inherent advantage in emitting lower CO2 emissions compared to their Diesel counterparts. Additionally, their aftertreatment system can be simpler and less costly as NOx reduction is handled simultaneously with CO/HC oxidation by a Three-Way Catalyst (TWC). The conversion of methane over a TWC shows a complex behavior, significantly different than non-methane hydrocarbons in stoichiometric gasoline engines. Its performance is maximized in a narrow A/F window and is strongly affected by the lean/rich cycling frequency. Experimental and simulation results indicate that lean-mode efficiency is governed by the palladium’s oxidation state while rich conversion is governed by the gradual formation of carbonaceous compounds which temporarily deactivate the active materials. Lean/rich cycling around stoichiometry enables a higher CH4 oxidation as the oxygen storage seems to balance the

Karamitros, Dimitrios, Ibraimova, Adjer, Konstantinidis, Konstantinos, Koltsakis, Grigorios, Choi, Sungmu, Cho, Jiho

Exhaust Slip-Stream Sampling System for Aftertreatment Device Testing

2024-01-2703

04/09/2024

Design, testing, and implementation of new aftertreatment devices under various engine operating conditions is necessary to meet increasingly stringent regulatory mandates. One common aftertreatment device, the catalytic converter, is typically developed at a reduced scale and tested using predefined fluid compositions sourced from bottle gases and can undergo both species and temperature cycling in addition to steady-state testing. However, these bench-top conditions may differ from real-world operation in terms of flow-rates, species composition, and temperatures experienced. Transitioning from small-scale bench-top testing to full-scale engine applications requires larger monoliths that therefore have a significant amount of catalyst slurry to be washcoated, which increases cost and fabrication time. Being able to experience realistic emission streams under scaled flowrates would allow for a physically smaller catalyst testing at matched space velocities resulting in faster, more

Loprete, Jason, Ristow Hadlich, Rodrigo, Sirna, Amanda, Assanis, Dimitris, Mon, Tala, Kyriakidou, Eleni

Ultra-Downsizing of ICEs Based on True Atkinson Cycle Implementations. Thermodynamic Analysis and Comparison on the Indicated Fuel Conversion Efficiency of Atkinson and Classical ICE Cycles

2024-01-2096

04/09/2024

Ultra-Downsizing (UD) was introduced as an even higher level of downsizing for Internal Combustion Engines ICEs, see [2] SAE 2015-01-1252. The introduction of Ultra Downsizing (UD) aims to enhance the power, efficiency, and sustainability of ICEs while maintaining the thermal and mechanical strain within acceptable limits. The following approaches are utilized: 1 True Atkinson Cycles are implemented utilizing an asymmetrical crank mechanism called Variable Compression and Stroke Ratios (VCSR). This mechanism allows for extended expansion stroke and continuous adjustment of the Volumetric Compression Ratio (VCR). 2 Unrestricted two or more stage high-pressure turbocharging and intensive intercooling: This setup enables more complete filling of the cylinder and reduces the compression work on the piston, resulting in higher specific power and efficiency. 3 The new Load Control (LC) approach is based to continuous VCR adjustment. By adjusting the VCR without resorting to excessive

Gheorghiu, Victor

Further Advances in Demonstration of a Heavy-Duty Low NOX System for 2027 and Beyond

2024-01-2129

04/09/2024

Multiple areas in the U.S. continue to struggle with achieving National Ambient Air Quality Standards for ozone. These continued issues highlight the need for further reductions in NOX emission standards in multiple industry sectors, with heavy-duty on-highway engines being one of the most important areas to be addressed. Starting in 2014, CARB initiated a series of technical demonstration programs aimed at examining the feasibility of achieving up to a 90% reduction in tailpipe NOX, while at the same time maintaining a path towards GHG reductions that will be required as part of the Heavy-Duty Phase 2 GHG program. These programs culminated in the Stage 3 Low NOX program, which demonstrated low NOX emissions while maintaining GHG emissions at levels comparable to the baseline engine. Building on that prior program effort, EPA continued to support further Low NOX demonstration efforts in support of the development of new Federal Emissions Standards for heavy-duty highway vehicles and

Sharp, Christopher, Neely, Gary, Zavala, Bryan, Rao, Sandesh, McDonald, Joseph, Sanchez, James L.

A Rapid Catalyst Heating System for Gasoline-Fueled Engines

2024-01-2378

04/09/2024

Increasingly stringent tailpipe emissions regulations have prompted renewed interest in catalyst heating technology – where an integrated device supplies supplemental heat to accelerate catalyst ‘light-off’. Bosch and Boysen, following a collaborative multi-year effort, have developed a Rapid Catalyst Heating System (RCH) for gasoline-fueled applications. The RCH system provides upwards of 25 kW of thermal power, greatly enhancing catalyst performance and robustness. Additional benefits include reduction of precious metal loading (versus a ‘PGM-only’ approach) and avoidance of near-engine catalyst placement (limiting the need for enrichment strategies). The following paper provides a technical overview of the Bosch/Boysen (BOB) Rapid Catalyst Heating system – including a detailed review of the system’s architecture, key performance characteristics, and the associated impact on vehicle-level emissions

Disch, Christian, O'Donnell, Ryan, Singh, Ripudaman, Chutipassakul, Somjai, Krein, William, Heinzelmann, Frank, Oesterle, Matthias

Effective Utilization of Pt Catalyst in Three-Way Catalytic System by Employing Calcined Ceria with Alumina

2024-01-2133

04/09/2024

To satisfy the stringent regulations for exhaust gas emissions from gasoline-powered vehicles, large amounts of Rh and Pd have often been employed in three-way catalysts (TWCs) as the main active components. On the other hand, Pt-based TWCs are not often used in gasoline vehicles because Pt is readily sintered by its exhaust gases at approximately 1000 °C [1, 2]. In general, Pt-based TWCs must be located away from large thermal loads to maintain the active sites for gas purification. Based on this background, we previously reported that employing a small amount of CeO2 calcined at 1000 °C (cal-CeO2) in Pt-based TWCs was one of the most effective approaches for improving the catalytic activity without increasing the amount of Rh and Pd [3]. The effect of cal-CeO2 was attributed to the higher redox performance and Pt dispersion derived from the strong interactions between Ce and Pt. Therefore, the resulting Pt-based TWCs exhibited high catalytic performance, despite the low specific

Morita, Itaru, Tanaka, Hiroki, Saeki, Shohei, Isayama, Akihiro, Iwashina, Katsuya, Nagao, Yuki, Endo, Yoshinori, Wakabayashi, Takashi, Haneda, Masaaki

A Three-Way Catalyst Model for a Bio-Methane Heavy-Duty Engine: Characterization at Different Lambda

2024-01-2084

04/09/2024

Given the spread of natural gas engines in low-term toward decarbonization and the growing interest in gaseous mixtures as well as the use of hydrogen in Heavy-Duty (HD) engines, appropriate strategies are needed to maximize thermal efficiency and achieve near-zero emissions from these propulsor systems. In this context, some phenomena related to real-world driving operations, such as engine cut-off or misfire, can lead to inadequate control of the Air-to-Fuel ratio, key factor for Three-Way Catalyst (TWC) efficiency. Goal of the present research activity is to investigate the performance of a bio-methane-fueled HD engine and its Aftertreatment System (ATS), consisting of a Three-Way Catalyst, at different Air-to-Fuel ratio. An experimental test bench characterization, in different operating conditions of the engine workplan, was carried out to evaluate the catalyst reactivity to a defined pattern of the Air-to-Fuel ratio. Through the detection of key performance parameters and

Di Maio, Dario, Guido, Chiara, Napolitano, Pierpaolo, Beatrice, Carlo

Algorithm to Calibrate Catalytic Converter Simulation Light-Off Curve

2024-01-2630

04/09/2024

Spark ignition engines utilize catalytic converters to reform harmful exhaust gas emissions such as carbon monoxide, unburned hydrocarbons, and oxides of nitrogen into less harmful products. Aftertreatment devices require the use of expensive catalytic metals such as platinum, palladium, and rhodium. Meanwhile, tightening automotive emissions regulations globally necessitate the development of high-performance exhaust gas catalysts. So, automotive manufactures must balance maximizing catalyst performance while minimizing production costs. There are thousands of different recipes for catalytic converters, with each having a different effect on the various catalytic chemical reactions which impact the resultant tailpipe gas composition. In the development of catalytic converters, simulation models are often used to reduce the need for physical parts and testing, thus saving significant time and money. However, calibration of these models can be challenging and requires significant time

Wilson, John Parley, DelVescovo, Dan

The Development of a Zeolite-Based Cold-Start Catalyst (CSC) for China 6b Vehicles (Conventional & Hybrid) to Meet the Next Chinese Vehicle Emission Standard, Part II

2024-01-2656

04/09/2024

This is a follow-up report about the development of a cost-effective Palladium (Pd) zeolite-based (HC/NOx trap type) cold-start catalyst (CSC) [1] to meet the future more stringent Chinese vehicle tailpipe emission standard. The impacts of Pd /stabilizer combination within zeolite for the HC/NOx trapping efficiency, the high temperature aging and the durability of the CSCs will be demonstrated by the laboratory results within this paper. The feasibility of a Cu zeolite, a popular non-precious metal ion- zeolite CSC for vehicle applications with respect to cost saving options will be demonstrated. A more complete picture of the effects of PGM/stabilizer within the zeolite to the functions of a CSC will also be summarized in this paper. All results indicate clearly that without the PGM/stabilizer within the zeolite, it would be difficult for the zeolite-based HC/NOx trap type CSC catalyst to be practically used for a vehicle application. The bag and second by second vehicle test results

Xu, Lifeng, Zhao, Fucheng, Wei, Hong, Zhao, Pengfei, Zhao, Jiajia, Wang, Lin, Qian, Wangmu, Qian, Menghan

Sulfur Impact on Methane Steam Reforming over the Stoichiometric Natural Gas Three-Way Catalyst

2024-01-2633

04/09/2024

The steam reforming of CH4 plays a crucial role in the high-temperature activity of natural gas three-way catalysts. Despite existing reports on sulfur inhibition in CH4 steam reforming, there is a limited understanding of sulfur storage and removal dynamics under various lambda conditions. In this study, we utilize a 4-Mode sulfur testing approach to elucidate the dynamics of sulfur storage and removal and their impact on three-way catalyst performance. We also investigate the influence of sulfur on CH4 steam reforming by analyzing CH4 conversions under dithering, rich, and lean reactor conditions. In the 4-Mode sulfur test, saturating the TWC with sulfur at low temperatures emerges as the primary cause of significant three-way catalyst performance degradation. After undergoing a deSOx treatment at 600 °C, NOx conversions were fully restored, while CH4 conversions did not fully recover. Experimental data under fixed lambda conditions reveal that sulfur stored on the catalyst leads to

Kim, Mi-Young, Dadi, Karthik Venkata, Gong, Jian, Kamasamudram, Krishna

Surface Modification of Henequen Fibers with Catalyst for Improving Mechanical and Thermal Properties in Phenolic Composites for Automotive Uses

2024-01-5029

02/27/2024

In this study, henequen fibers that had been treated with NaOH were used as reinforcements in phenolic-based materials. The hot-pressing method was used to create composites, which were then tested for tensile, flexural, fundamental, and thermogravimetric characteristics. When compared with samples that were untreated, the total attributes of fiber interface modification and treatment improved. The treated varieties of 50% henequen materials had the best tensile qualities of all composites, although their flexural values fell somewhat in comparison to the unprocessed materials. Fiber processing reduced the three-point bending characteristics of henequen composites. SEM was used to investigate the behavior of matrix and fiber bonding prior to and following pretreatment. Processed with 50% henequen resulted in improved fiber dispersion, 60% henequen resulted in void content, whereas 40% henequen resulted in inadequate fiber/matrix interface bonding. Thermogravimetric evaluation was used

Seeniappan, Kaliappan, Natrayan, L.

Innovative Catalysts for Biodiesel Generation from Edible Oils: Paving the Way for Cleaner Automobiles

2023-01-5125

02/23/2024

The study aims to produce biodiesel from waste cooking oil and compare the effects of two different catalysts (KOH and CaO) on the transesterification process. Homogeneous catalysts and heterogeneous catalysts are the two types of catalysts used in the transesterification process to produce biodiesel. In the present investigation, homogeneous catalysts KOH and heterogeneous catalyst CaO are used in the transesterification reaction. Catalysts are used to accelerate the reaction and increase reaction efficiency. The reaction temperature is set at 65°C. A methanol-to-waste cooking oil ratio of 6:1 is used for KOH and 8:1 for CaO. The catalyst amount is maintained at 2% of the weight of palmitic acid relative to the weight of waste cooking oil. The reaction time is 150 minutes for KOH and 240 minutes for CaO catalysts. The blends include B50C (50% biodiesel with CaO as catalyst and 50% conventional diesel fuel), B50K (50% biodiesel with KOH as catalyst and 50% conventional diesel fuel

Devan, P.K., Balasubramanian, M., Madhu, S., Prathap, P.

A Mechanism to Maintain Negative Crankcase Pressure in Turbocharged Gas Engine to Reduce Particulate Number to Meet Euro-VI Emission Regulation

2024-26-0145

01/16/2024

Emissions regulation continually drives the automotive industry to innovate and develop. This pushes to introduce mechanism to maintain negative crankcase pressure in gas engine to meet this changing regulation. The way a turbocharger is used, to meet engine performance, can impact the pressure balance over the compressor and turbine end seals. This pressure difference can allow oil to leak through turbocharger seals. In normal engine operating condition the pressure in the turbocharger end housings is higher than the bearing housing and oil/gas flows into the bearing housing, through the oil drain to the crankcase. Under certain operating conditions, such as low idle and motoring, this pressure difference can be reversed with a higher bearing housing pressure than the pressure behind the turbine wheel. Under this condition oil will flow out of the bearing housing to the recess behind the turbine wheel, will increase the exhaust tail pipe emission, high oil consumption and damages the

R, Mahesh Bharathi

Three Way Catalyst with Faster Light-Off Substrates – A Promising Approach to Reduce Tailpipe Emissions

2024-26-0142

01/16/2024

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 [1]. However, the introduction of RDE norms in BS6.2 [1] demanded further reduction in emissions under real time operating conditions – start-stop, hard acceleration, 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 significantly 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 (where some part of exhaust heat

Kale, Vishal Maruti, M, Ravisankar, Hosur, Viswanatha, Sridhar, S, Bhimavarapu, Aditya, Lende, Nilesh Ashok, Rose, Dominik, Tao, Tinghong

Experimental Emission Characteristics Study of Ethanol-Gasoline Fuel Blends on a GDI Engine with a Three-Way Catalyst

2024-26-0155

01/16/2024

Ethanol-gasoline blended fuels have been widely implemented in Indian markets followed by the Govt of India’s road map as ethanol reduces life-cycle greenhouse gas emissions and improves anti-knock performance. However, effects of Ethanol Blending on engine out emissions characteristics including particulates from gasoline direct injection (GDI) engine remains under development and investigation. In this study the effect of ethanol blended gasoline fuels with two blending rates 10% and 20% (v/v %) on catalyst conversion efficiencies and emissions on a 1.2 litre 3-cylinder turbo GDI engine is investigated. The addition of ethanol to gasoline fuel enhances the Octane rating (RON) of the blended fuels, oxygen content and changes Reid vapor pressure (RVP). The influence of lambda biasing, and lambda trim controller has been tested. The approach for calibration was adopted based on achieving the target pollutant conversion efficiencies. Test bench results indicated that with E10 blend all

R, Navaneetha Kannan, S, Easwar Ram, S, Satish Kumar, Karthi, Ramanathan, Ramakrishnan, Muthu

Study of Changes in Exhaust After-Treatment System Components in M & N Category Vehicles from the RDE Monitoring Stage to the RDE Compliance Stage

2024-26-0150

01/16/2024

Bharat Stage VI emission norms were implemented in India in two stages: Stage I from April 1, 2020, and Stage II from April 1, 2023. For M & N category vehicles, the RDE test along with other applicable certification tests is mandatory for obtaining a BSVI compliance certificate during stages I and II. The RDE test is conducted on roads under real driving conditions, unlike the Type-I test, which uses a predefined cycle on the chassis dynamometer, during which the ambient temperature and other environmental conditions are controlled in a narrow range. During BSVI Stage I for the RDE test, there was no limit for any pollutant. Therefore, it is considered as the RDE monitoring stage, and from BS-VI Stage II, limits are enforced on a few pollutants (NOX and PN) as notified in notification GSR 226(E) dated March 27, 2023. Therefore, it is considered the RDE compliance stage. During the RDE monitoring phase, emissions from M & N category vehicles are comparatively higher because of several

Singh, Abhay Pratap, Bathina, Revanth Kumar, Thakare, Kiran Prabhakar

A Novel Method for Urea Concentration Deterioration Detection in BSVI Heavy Duty Engine

2024-26-0154

01/16/2024

Diesel Exhaust Fluid (DEF) concentration monitoring is done to detect the concentration at which the emission thresholds are exceeded in BSVI engines [1]. This paper introduces a novel method to model the fault monitoring system with enable conditions designed to detect deterioration in DEF concentration, while reducing misdetection. This eliminates the need for dedicated sensor, reduces complexity, cost, and potential sensor-related failure modes. Traditionally, Diesel Exhaust Fluid quality sensors have been employed to measure the absolute concentration of Diesel Exhaust Fluid in the aqueous solution of urea [2]. This information is used to detect usage of poor quality DEF which results in increase in NOx emission beyond legal limits. The proposed method leverages the strong relationship between catalyst conversion efficiency and Diesel Exhaust Fluid concentration for modelling a fault monitoring system which also takes inputs from various other sensors, to make the system fault

Venkat, Harish, Kumar, Gokul Elumalai, Kumar, Kosalaraman, G, Vijayakumar

Enhancing the Performance of DOC and SCR After-Treatment Devices Using Statistical Techniques and Heating Strategies

2023-28-0128

11/10/2023

Exhaust gas emissions from compression ignition engines are the most hazardous contaminants to human beings as well as the atmosphere. This research work contributes to develop a combined technology that targets the reduction in HC, CO, smoke and NOx emissions collectively without any modification in engine fuel or injection strategy. Slight changes in the exhaust after- treatment system will help in meeting the goal of reduced standards. DOC and SCR devices fitted at the exhaust gas pipe reduces CO, HC, smoke, and NOx emissions produced by the CI engine. A combination of aluminum oxide- cerium oxide and iron oxide are used as SCR and DOC catalysts, whose preparation is done by impregnation method and their performance is tested on a SCR+DOC bed. The injection of aqueous urea solution is varied from 200 ml to 600 ml by intervals of 200 ml at different load conditions. Response parameters for various experiments are predicted using response surface methodology. Utilizing this novel

V, Praveena, R, Rajarajeswari, Stephen, Deborah

Experimental and Modeling Study of NH ₃ -SCR on a Hydrocarbon-Poisoned Cu-CHA Catalyst

2023-01-1659

10/31/2023

A urea-selective catalytic reduction (SCR) system is used for the reduction of NOx emitted from diesel engines. Although this SCR catalyst can reduce NOx over a wide temperature range, improvements in NOx conversion at relatively low temperatures, such as under cold-start or low-load engine conditions, are necessary. A close-coupled SCR (cc-SCR), which was set just after the engine exhaust manifold, was developed to address this issue. The temperature of the SCR catalyst increases rapidly owing to the higher exhaust temperatures, and NOx conversion is then enhanced under cold-start conditions. However, since the diesel oxidation catalyst is not installed before the SCR catalyst, hydrocarbon (HC) emissions pass directly through the SCR catalyst and poison it, leading to lower NOx conversion. Therefore, the mechanism of NOx conversion reduction on HC-poisoned SCR catalysts are required to be studied. In this study, the effects of HC poisoning on the NOx conversion of Cu-CHA catalysts

Tanaka, Kotaro, Dobashi, Ibuki, Sakaida, Satoshi, Konno, Mitsuru

Post-Mortem Analysis of DAAAC and Conventionally Aged Aftertreatment Systems

2023-01-1656

10/31/2023

Upcoming regulations from CARB and EPA will require diesel engine manufacturers to validate aftertreatment durability with full useful life aged components. To this end, the Diesel Aftertreatment Accelerated Aging Cycle (DAAAC) protocol was developed to accelerate aftertreatment aging by accounting for hydrothermal aging, sulfur, and oil poisoning deterioration mechanisms. Two aftertreatment systems aged with the DAAAC protocol, one on an engine and the other on a burner system, were directly compared to a reference system that was aged to full useful life using conventional service accumulation. After on-engine emission testing of the fully aged components, DOC and SCR catalyst samples were extracted from the aftertreatment systems to compare the elemental distribution of contaminants between systems. In addition, benchtop reactor testing was conducted to measure differences in catalyst performance. Sulfur was deposited uniformly on the aftertreatment components while the oil derived

Seuser, Grant, Eakle, Scott, Rahman, Mohammed Mustafizur, Sharp, Christopher, Zavala, Bryan

Ammonia Emissions from Combustion in Gasoline Engines

2023-01-1655

10/31/2023

Forthcoming worldwide emissions regulations will start regulating ammonia emissions from light duty vehicles. At present, most light duty vehicles are powered by gasoline spark ignition engines. Sources of ammonia emission from such engines can be in-cylinder reactions (i.e. combustion) or downstream reactions across aftertreatment devices, particularly three-way catalysts. The latter has been known to be a major source of ammonia emissions from gasoline vehicles and has been extensively investigated. The former (combustion), less so, and thus is the subject of this work. A two-zone thermodynamic spark ignition engine model with a comprehensive chemical kinetics framework (C3MechV3.3 mechanism), after being validated against experimental ammonia emissions data, is used to study ammonia formation during combustion. Reaction pathways responsible for its generation are analysed and the effects of changing the following engine operational and combustion parameters are explored: engine load

Bajwa, Abdullah, Shankar, Varun, Leach, Felix

Characterization of an Integrated Three-Way Catalyst/Lean NOx Trap System for Lean Burn SI Engines

2023-01-1658

10/31/2023

The push for environmental protection and sustainability has led to strict emission regulations for automotive manufacturers as evident in EURO VII and 2026 EPA requirements. The challenge lies in maintaining fuel efficiency and simultaneously reducing the carbon footprint while meeting future emission regulations. Alcohol (primarily methanol, ethanol, and butanol) and ether (dimethyl ether) fuels, owing to their comparable energy density to existing fuels, the comparative ease of handling, renewable production, and suitable emission characteristics may present an attractive drop-in replacement, fully or in part as an additive, to the gasoline/diesel fuels, without extensive modifications to the engine geometry. Additionally, lean and diluted combustion are well-researched pathways for efficiency improvement and reduction of engine-out emissions of modern engines. Modern spark ignition (SI) engines typically employ various in-cylinder emission reduction techniques along with a three

Sandhu, Navjot Singh, Leblanc, Simon, Yu, Xiao, Reader, Graham, Zheng, Ming

GT-Suite Modeling of Thermal Barrier Coatings in a Multi-Cylinder Turbocharged DISI Engine for Catalyst Light-Off Delay Improvement

2023-01-1602

10/31/2023

Catalytic converters, which are commonly used for after-treatment in SI engines, exhibit poor performance at lower temperatures. This is one of the main reasons that tailpipe emissions drastically increase during cold-start periods. Thermal inertia of turbocharger casing prolongs the catalyst warm-up time. Exhaust enthalpy management becomes crucial for a turbocharged direct injection spark ignition (DISI) engine during cold-start periods to quickly heat the catalyst and minimize cold-start emissions. Thermal barrier coatings (TBCs), because of their low thermal inertia, reach higher surface temperatures faster than metal walls, thereby blocking heat transfer and saving enthalpy for the catalyst. The TBCs applied on surfaces that exchange heat with exhaust gases can increase the enthalpy available for the catalyst warm-up. A system-level transient heat transfer study using experimental or high-fidelity simulation techniques to evaluate the TBC application on various surfaces would be

Ravikumar, Avinash, Bhatt, Ankur, Gainey, Brian, Lawler, Benjamin

Impacts of eFuels on Solid and Gaseous Emissions of Powersport Two-Wheelers

2023-01-1838

10/24/2023

As alternative to electrification or carbon free fuels such as hydrogen, CO2-neutral fuels have been researched aiming to decrease the impact of fossil energy sources on the environment. Despite the potential benefit of capturing CO2 emission after combustion for own fuel production, the so-called eFuels also benefit by using a green source of energy during their fabrication. Among all the possibilities for eFuels, alcohols, ethers (such as MTBE and ETBE) and alternative hydrocarbons have shown positive impacts regarding emission reduction and performance when compared to standard gasoline. Previously in [1] and [2], synthetic fuels and methanol blends were tested at steady state conditions in order to verify advantages and drawbacks relative to gasoline, for power-sport motorcycles. However, for real-world operation, transient behavior must be investigated addressing critical topics such as emissions during engine / aftertreatment warm-up, catalyst light-off and its interaction with

Batalha, Guilherme Pellizzaro, Schurl, Sebastian, Schmidt, Stephan, Bonifer, Marcus

Exhaust Aftertreatment Technologies for PN Reduction of Motorcycles

2023-01-1846

10/24/2023

The objective of this experimental investigation was to analyze the effect of various exhaust gas aftertreatment technologies on particulate number emissions (PN) of an MPFI EU5 motorcycle. Specifically, three different aftertreatment strategies were compared, including a three-way-catalyst (TWC) with LS structure as the baseline, a hybrid catalyst with a wire mesh filter, and an optimized gasoline particulate filter (GPF) with three-way catalytic coating. Experimental investigations using the standard test cycle WMTC performed on a two-wheeler chassis dynamometer, while the inhouse particulate sampling system was utilized to gather information about size-dependent filtering efficiency, storage, and combustion of nanoparticles. The particulate sampling and measuring system consist of three condensation particle counters (CPCs) calibrated to three different size classes (SPN4, SPN10, SPN23). The study revealed that all three aftertreatment technologies were effective in reducing PN from

Schurl, Sebastian, Bonifer, Marcus, Schmidt, Stephan, Bretterklieber, Niko, Joshi, Pragati

Improvement of the EGR Dilution Tolerance in Gasoline Engines by the Use of a HSASI Pre-Chamber Spark Plug

2023-01-1805

10/24/2023

Charge dilution in gasoline engines reduces NOx emissions and wall heat losses by the lower combustion temperature. Furthermore, under part load conditions de-throttling allows the reduction of pumping losses and thus higher engine efficiency. In contrast to lean burn, charge dilution by exhaust gas recirculation (EGR) under stoichiometric combustion conditions enables the use of an effective three-way catalyst. A pre-chamber spark plug with hot surface-assisted spark ignition (HSASI) was developed at the UAS Karlsruhe to overcome the drawbacks of charge dilution, especially under part load or cold start conditions, such as inhibited ignition and slow flame speed, and to even enable a further increase of the dilution rate. The influence of the HSASI pre-chamber spark plug on the heat release under EGR dilution and stoichiometric conditions was investigated on a single-cylinder gasoline engine. The performance of the HSASI spark plug was compared with a passive pre-chamber spark plug

Holzberger, Sascha, Kettner, Maurice, Kirchberger, Roland

Simulation of Temperatures of Three Way Catalytic Converter for Motorcycles at Higher Temperatures

2023-01-1815

10/24/2023

For a quick reach to the operating temperatures, the three way catalytic converter is recently located closer to the engine and subjected to higher temperatures than before. At the same time, the three way catalytic converter has upper thermal limits. Therefore, the operating temperatures have to be estimated accurately in the early period of product development. In this research, the four analysis methods are linked with the one-dimensional engine cycle simulation to achieve the goals. Firstly, for the estimation of gas temperatures at the exhaust port of the engine, the combustion analysis using the 3D-CFD was conducted to accurately simulate the way the heat was generated. Then, for the estimation of heat dissipation from the exhaust system to the atmosphere, the heat conduction analysis coupled with the air flow analysis around the vehicle body using the 3D-CFD was conducted. To take into considerations the heterogeneity of reactions in the three way catalytic converter, the gas

Shigeno, GENKI, Fujita, Shinji, yogo, toyoyuki

Development of Detailed Surface Reaction Mechanism of CO/ NO/ O ₂ System for Three Way Catalyst Based on Gaseous and Surface Species Analyses

2023-32-0122

09/29/2023

In this study, we determined the detailed reaction mechanism of CO/NO/O2 for automotive three way catalysts. The N2O formation process obtained from measurements of the reaction properties and the formation process of adsorbed NCO species obtained from surface analysis of platinum group metals were added to a previous detailed surface reaction mechanism. The computational accuracy of the developed reaction mechanism was verified by the one-dimensional simulation software BOOST, and it was found to be sufficient for any combination of platinum group metals and gas concentrations

Matsumoto, Yuhei, Shimokuri, Daisuke, Miyoshi, Akira, Hinokuma, Satoshi, Murakami, Hiroshi, Kawano, Michiharu

A Study of Multi-Functional Membrane Filters made of Fine Catalyst Particles

2023-32-0125

09/29/2023

A multi-functional membrane filter was developed through deposition of agglomerated Three-Way Catalyst particles with a size of 1 ~ 2 microns on the conventional bare particulate filter. The filtration efficiency reaches almost 100 % from the beginning of soot trapping with a low pressure drop and both reductions of NO and CO emission were achieved

Hanamura, Katsunori, Fujii, Shinpei, Teerapat, Suteerapongpun

New Concept Exhaust Manifold for Next-Generation HEV and PHEV

2023-32-0062

09/29/2023

HEV and PHEV require an improved aftertreatment system to clean the exhaust gas in various driving situations. The efficiency of aftertreatment system is significantly influenced by the residence time of the gas in a catalyst which gas flow has generally strong pulsation. Simulation showed up to 70% reduction of exhaust gas emission if the pulsation could be completely attenuated. A new concept exhaust manifold was designed to minimize pulsation flow by wall impingement, with slight increase of pressure loss. Experimental results with new concept exhaust manifold showed exhaust gas emission were reduced 16% at cold condition and 40% at high-load condition

Ito, Hirokazu, Seguchi, Kazuhiko, Nakayama, Shigeki, Fukuma, Takao

Visualization of Physical / Thermal Evaporation Phenomena with Experimental and PIV-DDM Analysis in Urea-SCR Dosing System of Multi-Phase Flow

2023-32-0098

09/29/2023

This study was visualized by experimental and numerical analysis for the unknown injected droplet phenomena with the multi-phase flow in the Urea-SCR dosing system. Visualization experiments were conducted on the droplet behavior inside the pipe with simulated urea SCR injection system. Although the total number of droplets decreases at gas temperatures of 150°C and 200°C, a significant number of injected droplets remained at the position corresponding to the SCR catalyst. That is physical kinetic energy was found to dominate over thermal evaporation. However, the impingement of droplets into the pipe wall had occurred complex behavior by physical/thermal evaporation, and these droplets weren't on gas airflow at the lower part of the pipe. Furthermore, these actual phenomena were reflected in experimental coefficients for new reduction model analysis instead of CFD

NOHARA, Tetsuo, SUGIYAMA, Naoki, NARA, Shotaro, ONO, Jyo, ONOUE, Hiroki, OSADA, Rina, KAWAMOTO, Yuki, OCHIAI, Masayuki, TAKAHASHI, Shun, OOSUMI, Kazuo, ISHIKAWA, Naoya

Effects of Different Driving Behavior during Actual Road Driving on Ammonia Emissions from Gasoline Vehicles

2023-32-0095

09/29/2023

Three-way catalysts are used in gasoline vehicles for simultaneous purifying nitrogen oxide, carbon monoxide, and hydrocarbon in recent years. However, the reduction of ammonia emission generated in the three-way catalyst is pressing issue. In EURO 7, ammonia will also be subject to the Real Driving Emissions regulation, and its emissions must be reduced. Previous studies have shown that ammonia emissions are higher under fuel-rich conditions, suggesting that differences in driving behavior have a significant impact on ammonia emissions in real-world driving, which includes various driving environments. In this study, driving tests were conducted on a direct- injection gasoline vehicle equipped with a three-way catalyst and Portable Emission Measurement System and Sensor-based Emission Measurement System to investigate the actual ammonia emissions on actual roads. Sensor-based Emission Measurement System includes the system that can measure ammonia and nitrogen monoxide concentrations

Sato, Susumu, Chen, Jiaxin, Eang, Chanpaya, Tanaka, Kotaro, Tange, Takeshi

Potentials of Air Path Variabilities and Water Injection in HD Gas Engines

2023-24-0120

08/28/2023

The transportation sector, and commercial vehicles in particular, play an important role in global CO2 emissions. For this reason, the EU recently decided to reduce CO2 emissions from commercial vehicles by 30% until 2030. One alternative to conventional diesel propulsion is the usage of stoichiometric natural gas combustion. Due to the lowered C/H ratio and the cost effective exhaust after treatment (EAT) in form of a three way catalyst (TWC), less CO2 is emitted and it is possible to comply even with most stringent NOX legislations. However, the stoichiometric combustion of natural gas has also disadvantages. In particular, the throttling and retarded 50 % mass fuel burned (MFB50) positions due to knocking lead to efficiency losses. One way to minimize these is the usage of exhaust gas re-circulation (EGR), Miller cycle and water injection. The reduced knocking tendency allows the geometric compression ratio to be increased further, which leads to an additional efficiency advantage

Betz, Marius, Eilts, Peter

Improvement of Post-Oxidation for Low-Emission Engines through 3D-CFD Virtual Development

2023-24-0107

08/28/2023

There is a growing need for low-emissions concepts due to stricter emission regulations, more stringent homologation cycles, and the possibility of a ban on new engines by 2035. Of particular concern are the conditions during a cold start, when the Three-Way Catalyst is not yet heated to its light-off temperature. During this period, the catalyst remains inactive, thereby failing to convert pollutants. Reducing the time needed to reach this temperature is crucial to comply with the more stringent emissions standards. The post oxidation by means of secondary air injection, illustrated in this work, is a possible solution to reduce the time needed to reach the above-mentioned temperature. The strategy consists of injecting air into the exhaust manifold via secondary air injectors to oxidize unburned fuel that comes from a rich combustion within the cylinder. This strategy can be implemented without major modifications to the engine's hardware or control system, making it an attractive

Pipolo, Mario, Kulzer, Andre, Chiodi, Marco, Moriyoshi, Yasuo

Pre-investigations on Reactive Exhaust Gas Recirculation for a Naturally Aspirated Cogeneration Gas Engine

2023-01-1212

06/26/2023

Given its ability to be combined with the three-way catalyst, the stoichiometric operation is significantly more attractive than the lean-burn process, when considering the increasingly severe NOx limit for cogeneration gas engines in Germany. However, the high temperature of the stoichiometric combustion results in increased wall heat losses, restricted combustion phasings (owing to knock tendency) and thus efficiency penalties. To lower the temperature of the stoichiometric combustion and thus improve the engine efficiency, exhaust gas recirculation (EGR) is one of the most effective means. Nevertheless, the dilution with EGR has much lower tolerance level than with excess air, which leads to a consequent drop in the thermal efficiency. In this regard, reducing the water vapor concentration in the recirculated exhaust gas and increasing the EGR reactivity are two potential measures that may extend the mixture dilution limit and result in engine efficiency benefits. Here, the reactive

Beltaifa, Youssef, Kettner, Maurice, Eilts, Peter, Ruchel, Bosse, Fröstl, Sebastian

Comparability of Hot-Wire Estimates of Liquid Water Content in SLD Conditions

2023-01-1423

06/15/2023

Future compliance to FAA 14 CFR Part 25 and EASA CS-25 Appendix O conditions has required icing wind tunnels to expand their cloud simulation envelope, and demonstrate accurate calibration of liquid water content and droplet particle size distributions under these conditions. This has led to a renewed community interest in the accuracy of these calibrations, and the potential inter-facility bias due to the choice of instrumentation and processing methods. This article provides a comparison of the response of various hot-wire liquid water content instruments under Appendix C and supercooled large droplet conditions, after an independent similar analysis at other wind tunnel facilities. The instruments are being used, or are under consideration for use, by facilities collaborating in the ICE GENESIS program. For droplet median volume diameters (MVDs) between about 15 and 250 μm, cylindrical hot wire LWC sensors were found to consistently and increasingly under-read measurements from

Esposito, Biagio M., Orchard, David, Lucke, Johannes, Nichman, Leonid, Bliankinshtein, Natalia, Lilie, Lyle, Catalano, Pietro, D'Aniello, Francesco, Strapp, J. Walter

Snow Particle Characterization. Part A: Statistics of Microphysical Properties of Snow Crystal Populations from Recent Observations Performed during the ICE GENESIS Project

2023-01-1492

06/15/2023

Measurements in snow conditions performed in the past were rarely initiated and best suited for pure and extremely detailed quantification of microphysical properties of a series of microphysical parameters, needed for accretion modelling. Within the European ICE GENESIS project, a considerable effort of natural snow measurements has been made during winter 2020/21. Instrumental means, both in-situ and remote sensing were deployed on the ATR-42 aircraft, as well as on the ground (ground station at ‘Les Eplatures’ airport in the Swiss Jura Mountains with ATR-42 overflights). Snow clouds and precipitation in the atmospheric column were sampled with the aircraft, whereas ground based and airborne radar systems allowed extending the observations of snow properties beyond the flight level chosen for the in situ measurements. Overall, five flight missions have been performed at different numerous flight levels (related temperature range from -10°C to +2°C) beyond the ‘Les Eplatures’ airport

Jaffeux, Louis, Schwarzenboeck, Alfons, Coutris, Pierre, Febvre, Guy, Dezitter, Fabien, Aguilar, Boris, billault-Roux, Anne-claire, Grazioli, Jacopo, Berne, Alexis, Köbschall, Kilian, Jorquera, Susana, Delanoe, Julien

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