Browse Topic: Catalytic converters

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Experimental Study of Warm-Up And Startability Operations in a Spark Ignition Engine Fueled with Ethanol Gasoline Blends2026-01-07387/1/2026
The mitigation of Greenhouse Gas (GHG) emissions poses a major challenge for the transportation sector, driving the need for renewable fuels. Bioethanol represents a promising fuel for Spark-Ignition (SI) engines, combining a reduced life-cycle CO₂ impact with advantageous combustion properties. However, despite its proven performance under steady-state conditions, the widespread of fuels with high ethanol content is still constrained by significant difficulties during engine cold-start operation. This study aims to experimentally assess the effect of ethanol concentration on cold-start performance and warm-up transient behavior of a Naturally Aspirated (NA), Port Fuel Injected (PFI) SI engine. Warm-up tests were conducted at an operating condition of 2000 rpm engine speed and 20 Nm torque using three fuels with increasing ethanol content: commercial gasoline (E5), E30 and E60. In addition, dedicated startability tests were carried out for E60 and neat ethanol (E100) at different initial engine wall temperatures to evaluate fuel sensitivity to thermal conditions during engine start. The experimental results indicate that increasing ethanol concentration has a negligible effect on the overall duration of the warm-up process, while leading to a modest reduction in both engine wall and exhaust gas temperatures. At the same time, E100 displays severe startability limitations at low initial wall temperatures, requiring repeated cranking attempts before stable operation can be achieved. The same startability issues have been observed for E60 but with limited intensity. Two minimum engine wall temperature ranges were identified for reliable cold-start operation at 20-25 °C for E60 and 25-30°C for E100. Overall, these findings experimentally confirm the dominant influence of engine thermal conditions on the reliable startability of ethanol-fueled spark-ignition engines.
Falbo, Luigi, Falbo, Biagio, Perrone, Diego, Castiglione, Teresa
AirCARE: Assessing the Impact of an Integrated Air Purification System on Vehicle Thermal Management2026-01-02724/7/2026
The increasing concentration of atmospheric pollutants in urban environments necessitates innovative solutions to mitigate their impact on public health and the environment. This work presents the AirCARE project, which investigates the integration of a catalytic converter and a particulate filter with a vehicle's radiator to create an active air purification system. The primary objective is to evaluate the feasibility and performance implications of this integrated system on the vehicle's thermal management. A comprehensive methodology combining computational modeling and experimental testing was employed. A 1D longitudinal vehicle model was developed to simulate the powertrain's heat generation and the cooling system's performance under various representative driving conditions. This model allows for a parametric study of the radiator, assessing the impact of the additional components on its heat exchange efficiency. Concurrently, experimental tests were conducted on a radiator to measure the pressure drop across the integrated filter and to validate the heat exchange performance predicted by the simulations. This paper focuses on the results from the vehicle and component-level simulations and the corresponding experimental validation of the radiator's fluid-dynamic and thermal behavior. The results provide a quantitative analysis of the trade-offs between the potential for pollutant abatement and the constraints imposed on the vehicle's cooling system. The study identifies key design parameters and operating conditions that influence system performance, offering insights for optimizing the integration. The findings demonstrate the technical considerations required to implement such a system without compromising vehicle safety and performance, establishing a foundation for the future development of vehicles as mobile air purification platforms.
de Carvalho Pinheiro, Henrique, Sartoretti, Enrico
Effect of Exhaust Gas Components on Oxygen Storage Capacity Measurements of Automotive Catalysts2026-01-03604/7/2026
Three-way catalytic converters (TWC) are one of the most popular methods to help reduce harmful tailpipe emissions emitted from internal combustion (IC) vehicles. To help improve conversion efficiency, TWCs can store and release oxygen via an oxygen storage capacity (OSC) mechanism. During engine control unit (ECU) calibration, on board OSC measurements are correlated to TWC and vehicle emissions to monitor emissions performance throughout the full useful life (FUL) of the vehicle. It is known that different test conditions, including temperature, space velocity and background gases in the exhaust stream affect OSC measurement, potentially altering the calculated OSC values and thus the perceived level of OSC and emissions preformance during operation. This study utilises an OMEGA test bench to complete OSC measurements on the full-scale automotive catalyst samples to quantify the effects of different background gases including carbon monoxide, hydrocarbons and nitric oxide on OSC measurements, concluding that all background gases studied affect measured OSC values. The study revealed that hydrocarbons had the largest effect on OSC measurement increasing OSC values by up to 50%. It was concluded that the increase in OSC measurement with injected hydrocarbons was due to the breakdown of hydrocarbons on the catalyst surface during rich periods of operation increasing the amount of oxygen required to fully oxidise the catalyst resulting in a larger perceived OSC measurement. During the initial ECU calibration original equipment manufacturers (OEM) should consider these effects on OSC measurement and understand how this will affect perceived OSC and vehicle emissions performance for FUL and onboard diagnostics (OBD) applications. This will help ensure emissions compliance and guide optimized catalyst and engine calibrations.
Mc Grane, Liam, Douglas, Roy, Irwin, Kurtis, Woods, Andrew, Elliott, Matthew, Istrate, Oana, Nockemann, Peter
Alternate Catalyst for DOC in a Catalytic Converter2026-28-00162/12/2026
Emission norms have become much more stringent to reduce emissions from vehicles. Diesel engines in particular are the predominant contributors to higher emissions. Diesel Oxidation Catalyst (DOC) in diesel engine catalytic converter systems is the crucial component in reducing harmful emissions such as Carbon Monoxide (CO) and unburnt Hydrocarbons (HC). DOCs often rely on expensive noble metals like platinum, palladium, and rhodium as catalyst materials. This significantly raises the cost of emission control units. The proposed idea is to explore MnO2-CeO₂ (Manganese Oxide, Cerium Oxide) as an alternative catalyst to traditional DOC materials. The goal is to deliver effective oxidation performance while reducing overall system cost. MnO2-CeO₂ catalysts are promising because of their good low-temperature activity, oxygen storage capacity, and redox behavior. These features are helpful for diesel engines that operate under various conditions. They improve the oxidation of CO and HC, even during cold starts or at lower exhaust temperatures. The catalyst was successfully synthesized and applied to a honeycomb substrate, resulting in a fabricated catalytic converter prototype. Quantitatively, the fabricated MnO₂–CeO₂ coated prototype demonstrated a 43% reduction in CO, 47% reduction in HC, 27% reduction in NOx, and 41% reduction in PM during low-temperature exhaust testing (150 – 400 °C) during testing on a 1.5 L diesel engine. The results were based on repeated experimental runs using an uncoated substrate as baseline. The work also focuses on material accessibility and environmental sustainability by using non-noble, widely available metal oxides. The hypothesis of this study is that a MnO₂–CeO₂ catalyst synthesized via co-precipitation can deliver meaningful low-temperature oxidation performance at significantly lower cost compared to PGM-based DOCs. Thus, the project contributes a significant step toward developing more accessible and sustainable emission control technologies for the automotive industry.
C, Jegadheesan, T, Karthi, Rajendran, Pawan, Muruganantham, Kowshiik, S, Vaitheeshwaran
Misfires Detection in Bi-Fuel Engines – A Brief Note2026-26-01201/16/2026
With the expansion of compressed natural gas (CNG) filling station in India, bi-fuel vehicles are gaining popularity in recent times. Bi-fuel engine runs on more than one fuel, say in both CNG and petrol. Hence, the engine must be optimized in both the fuel modes for performance and emissions. However, due to the inherent differences in combustion characteristics: ignition dynamics and fuel properties, they pose a significant challenge in case of detection of misfires. Misfires are caused because of faulty injection systems and ignition systems and incorrect fuel mixture. Accurate detection is essential as misfires deteriorate the catalysts performance and may impacts emission. Misfires (or engine roughness) is calculated from engine crankshaft speed signal. In this study, the effectiveness of crankshaft-based misfires detection method, comparison of misfire signals magnitude in bi-fuel modes and practices developed for accurate detection of misfires is presented.
Thiyagarajan, Abhinav, N, Gobalakrishnan, R, Hema
Leveraging Telematics Big Data Analytics for Real-Time Monitoring of Catalytic Converter Failures and Root Cause Identification for Emission Compliance2026-26-05911/16/2026
The automotive industry is continuously evolving at high pace to meet rising customer expectations, reliability, reduced maintenance, and most relevant, compliance with stringent emission norms. Traditionally, the analysis of vehicle emissions relies heavily on periodic inspections and manual checks. These conventional methods are often time-consuming, prone to human error, and lack the ability to provide real-time insights. Also, identifying failures due to non-manufacturing issues require meticulous physical inspections and historical data reviews, which are not always accurate or timely. Telematics or Connected cars technology being one of the major technological innovations in recent times revolutionizes these processes by enabling real-time data exchange between vehicles and external systems. The current study presents an innovative approach to utilizing telematics data for real-time monitoring of vehicle emissions and pinpointing Catalytic converter failures by analyzing vehicle probe data retrieved from telematics system aimed to identify fuel adulteration events or CNG kit retrofitments that can compromise vehicle performance and longevity. The methodology involves continuous data transmission from telematics devices to the cloud, where the system monitors vehicle emissions in real-time and alerts customers of potential failures. Further to identify the cause of failure, the telematics raw data is processed and aggregated for analysis using statistical models to detect potential fuel tank cleaning due to incorrect or adulterated fuel filling done in the past. This process is validated through a two-level model, ensuring accuracy in detecting fuel adulteration instances. The key advantage of this approach lies in its server-based high-speed processing, which eliminates the resource burden involved during physical inspection and testing of failed parts and enhances detection capabilities compared to existing solutions. This innovative method not only improves vehicle maintenance and customer satisfaction but also ensures compliance with emission norms, thereby contributing to a cleaner and more sustainable environment.
Dev, Triyambak, Prasad, Kakaraparti Agam, Kalkur, Varun, Modak, Saikat, AGARWAL, Shashank, Chandra, Animesh, Paul, Varsha, Garg, Amit, Sundararaman, Venkataraman, Bose, Sushant
A Thermoelectric System for Emission Control Optimization in Two-Wheeler Automotive Applications2026-26-02181/16/2026
Environmental pollution is one of the growing concerns of our society. As vehicle emissions are a major contributor to air pollution, emission control is a primary goal of the Automotive industry. Vehicle emissions are higher due to improper combustion, which leads to toxic gases being generated from the exhaust system. Unburnt fuel is one of the leading causes of toxic pollutants such as Carbon Monoxide, Nitric Oxides (NOx) and Hydrocarbons. The catalytic converter converts these gases into less toxic substances such as Carbon Dioxide, Nitrogen, and water vapor. The catalytic converter performs efficiently after reaching its “Light Off” temperature, after which the catalyst becomes active. Hence, elevated temperature of the exhaust gases aids in efficient conversion. Presently, the gases from the exhaust system are approximately at a temperature of 300°C-600°C. This paper outlines the concept of a Peltier (Thermoelectric) Module - based system, which helps maintain the high temperature of the exhaust gases prior to entering the catalytic converter. Peltier Modules are thermoelectric devices well-known for their usage in heating/cooling applications. The proposed system includes a chamber in which the Peltier Module is embedded. As the gases flow through the chamber, the embedded Peltier Module, which is powered by the battery, increases the temperature inside the chamber. Therefore, with this concept, the components required to heat the catalytic converter could be potentially reduced, since the exhaust gases will be maintained at the targeted temperature required for better emission control. Moreover, the Peltier Module is also known to be used for electricity generation. Consequently, by generating electricity through heat utilization on the surface of the chamber, we provide an added benefit of this proposed concept. This can be achieved by mounting the Peltier Module on the hot surface of the chamber. The other side of the Peltier Module is exposed to ambient air and thereby a potential difference is created through the Seebeck Effect.
Venkateshwaran, Aishwarya, Soodlu, Shashikiran, M, Mathaiyan
CS Structure: New Metallic Catalyst Substrate Generation for 2- and 3-Wheeler Applications2026-26-02201/16/2026
Affordable, efficient and durable catalytic converters for the two and three-wheeler industry in developing countries are required to reduce vehicle emissions and to maintain them at a low level; and therefore, to participate in a cleaner and healthier environment. Especially, metallic catalyst substrates developed by Emitec Technologies GmbH with structured foils like the Longitudinal Structure (LS), or LS-Design® are fully compatible to this effort with more than 70% share of produced 2/3 Wheelers metallic catalyst substrates for the Indian market in 2024. One decade after the market introduction of this LS structure, Emitec Technologies GmbH will introduce now a new generation of foil structure: the Crossversal Structure (CS) or CS-Design®, that improves further the affordability, the efficiency of metallic catalytic converters, keeping the durability at same level as previous substrate generation. The paper will briefly review the development of metallic substrates for 2/3 wheelers applications, especially the development of structured foil substrates, describe the new foil structure CS, compare its performances to those of previously developed metallic substrates with structured LS foils. For this later purpose, experimental emission measurements under WMTC driving cycle on roller bench will be carried out on one Indian BS6 - OBD2 four stroke motorcycle. The results will be discussed and the benefits of CS for current and future motorcycle applications will be drawn.
Jayat, Francois, Seifert, Sven, Bhalla, Ashish, Ganapathy, Narayana Prakash
Development of a Hardware-In-the-Loop (HIL) Platform for Evaluating and Implementing Heated Injection Technology in GDI Engines2025-36-004812/18/2025
Reducing pollutant emissions remains a major challenge for the automotive industry, driven by increasingly stringent environmental regulations. While solutions such as electric vehicles (EVs) and hybrid electric vehicles (HEVs) have been developed, internal combustion engines (ICEs) continue to dominate many markets, requiring additional emission control strategies. Traditional technologies like catalytic converters and advanced injection systems primarily optimize performance once the engine reaches its operating temperature. However, during the cold start phase, when engine temperatures are below optimal, combustion efficiency drops, resulting in increased emissions of non-methane organic gases (NMOG) and nitrogen oxides (NOx). This phase is further compromised by factors such as fuel droplet size and suboptimal catalyst performance. In response, this work presents the development of a Hardware-in-the-Loop (HiL) platform to study the impact of heated injection technology on cold start emissions in a 1.0L Gasoline Direct Injection (GDI) engine. By integrating simulation, modeling, and experimental validation, this research evaluates the potential of heated injectors to reduce harmful emissions during engine cold starts. The proposed system leverages vehicle downtime —such as door unlocking and prestart moments—to preheat the injectors, aiming for faster combustion stabilization compared to conventional solutions like heated catalytic converters. It is important to note that this project is still ongoing. The experimental phase is pending the arrival of new equipment, including heated injectors and dedicated instrumentation for accurate measurement and validation. Therefore, the current article focuses on the modeling and simulation phases, while the experimental results will be addressed in future work. Initial expectations suggest that this approach can significantly lower NMOG emissions, offering a promising and efficient pathway for improving the environmental performance of future ICE-powered vehicles.
Triviño, Juan David Parra, Teixeira, Evandro Leonardo Silva, De Lisboa, Fábio Cordeiro, Aguilar, Raul Fernando Sánchez, Oliveira, Alessandro Borges De Sousa
Onboard Exhaust Capture and Carbon Sequestration for Off-Highway Vehicles: A Sustainable Approach to Emission Reduction2025-28-021511/6/2025
Off-highway vehicles (OHVs) in sectors such as mining, construction, and agriculture contribute significantly to global greenhouse gas (GHG) emissions, particularly carbon dioxide (CO₂) and nitrogen oxides (NOₓ). Despite the growth of alternative fuels and electrification, diesel engines remain dominant due to their superior torque, reliability, and adaptability in harsh environments. This paper introduces a novel onboard exhaust capture and carbon sequestration system tailored for diesel-powered OHVs. The system integrates nano-porous filters, solid-state CO₂ adsorbents, and a modular storage unit to selectively capture CO₂ and NOₓ from exhaust gases in real time. Captured CO₂ is then compressed for onboard storage and potential downstream utilization—such as fuel synthesis, carbonation processes, or industrial sequestration. Key innovations include: A dual-function capture mechanism targeting both CO₂ and NOₓ Lightweight thermal-regenerative adsorption materials Integration with existing diesel aftertreatment systems Simulation and bench-scale testing indicate up to 72% CO₂ capture efficiency under transient OHV duty cycles, with energy penalties managed below 6% of net engine output. The system offers a retrofit-compatible, scalable pathway to significantly reduce carbon emissions in hard-to-electrify sectors, serving as a bridge toward long-term carbon neutrality goals.
Vashisht, Shruti
On Board Monitoring of Water Injection Inducement System and Particulate Filter for 3-Wheeler BS VI OBD II B Diesel Vehicle Norms2025-32-008611/3/2025
To mitigate greenhouse emissions such as carbon monoxide (CO), carbon dioxides (CO2), oxide of nitrogen (NOx) and particulate matter reduction Government of India implemented Bharat Stage VI (BS-VI) norms from year 2020. Moving to more stringent emission norms poses challenges for automakers in several ways such as meeting exhaust emissions, on board diagnostic, drivers’ inducement, and particulate filter monitoring on vehicle. It is imperative to upgrade engine management system for on-board diagnostics (OBD) that refers to a vehicles self-diagnostic and reporting ability. On board diagnostics systems enables owner of vehicle to gain access of the various vehicle sub-systems. OBD-II standards were made more rigid, requiring the malfunction indicator lamp (MIL) to be activated if emission-related components fail. Also, vehicle emissions carbon monoxide (CO), oxide of nitrogen (NOx) and particulate matter not to exceed OBD thresholds. Consequently, the use of specific oxide of nitrogen (NOx) emission control systems became necessary in Bharat Stage VI for 3-wheeler applications. Additionally, the performance and integrity of the particulate filter must be monitored. Driver warnings, for water injection system, and particulate filter monitoring are essential during the operation of 3-wheeled vehicles to ensure correct operation of NOx emission control systems. The driver inducement requirements are designed to enforce and ensure the correct operation of the NOx control system, while particulate filter monitoring ensures the performance and integrity of the particulate filter. Present study deals with 3-wheeled diesel vehicles having port water injection technology on engine. As per automotive Indian standard for three-wheeler category vehicles, BS VI emission norms must have systems in place to monitor for malfunctions related to water quantity if they rely on the use of water stored in a separate tank to reduce emissions. This includes monitoring for low water levels and empty tanks, as well as ensuring the proper functioning of the dosing or injection subsystem. The driver inducement system must comply with water level indication, consumption monitoring, driver warning system, storage of failure information. Also, vehicle must comply with the OBD II-B requirements such as circuit continuity and rationality for all emission-related powertrain components, distance travelled since malfunction indication lamp glow, EGR and after-treatment system monitoring, For the driver inducement system algorithms were designed for input parameters which were captured from different sensor and actuators of engine and vehicle management system. These inputs were sent to the engine control unit (ECU), which processes the data and generates outputs to the water injector, display unit, diagnostic management system, warning lamps, buzzer, and instrument cluster. For particulate filter monitoring, a differential pressure sensor is added in the exhaust stream, which monitors the inlet and outlet pressure of the particulate filter. This monitoring of inlet and outlet pressure confirms the integrity of the particulate filter and detects malfunctions if any. This is novel concept for NOx emission control and catalyst monitoring control systems on diesel three-wheel vehicle application as per BS VI OBD II B legislation.
Jagtap, Pranjal, Syed, Kaleemuddin, Chaudhari, Sandip, Khairnar, Girish, Bhoite, Vikram, Reddy, Kameswar
Optimized Engine Off Time Estimation for Cold Start Detection in Emission Diagnostics2025-28-036610/30/2025
A cold start occurs when the engine is cranked after being off for a long time, enough for its temperature to drop down to the cold ambient levels. Cold start in an engine is a critical phase as it is characterized by elevated emissions. During a cold start, exhaust components such as catalytic converter do not operate in its optimal temperature zone leading to reduced efficiency in emission control. New regulations for engine emissions are becoming stringent for this condition, hence it is important to accurately determine cold start condition in an engine to optimize the emissions control strategy. Accurate engine off time calculation plays a crucial role in cold start detection, emissions control and On-Board Diagnostics (OBD-II) decision making. This engine off time if greater than 6 hours indicates one of the conditions to confirm a cold start. Other conditions such as Ambient temperature and coolant temperature along with the engine off time confirms a cold start. This paper presents a novel approach to calculate engine off time without any need for supplementary new hardware, leveraging detection of cold start to meet the new requirements for Cold start emission reduction strategy (CSERS) for OBD-II diagnostics. The proposed methodology utilizes Real time clock to estimate the time difference between a successful Engine Cranking and previous engine off to accurately estimate engine off time, enabling precise differentiation between a cold and a warm start.
MUTHA, MAYURESH, Talawadekar, Pradnya, Kale, Upendra
IRLAM-An Advanced Technology for NO x Measurement from Diluted Exhaust of a Light Duty Vehicle (LDV)2025-01-040310/7/2025
The United States Environmental Protection Agency (US-EPA) requires nitrogen oxides (NOx) measurement using Chemiluminescent Detectors (CLDs), Non-dispersive Ultraviolet (NDUV), and Zirconia Oxide (ZrO2) analyzers, as outlined in the 40 CFR Part 1065. Quantification of NO2 by CLD requires dual-CLDs; one dedicated to measuring the NO and another coupled with a NO2-to-NO converter to measure the total NOx. Measurement by using dual-CLDs involves mathematically subtracting NO from total NOx to get NO2 information. This requires perfect time alignments of both CLDs assigned for measuring NO and NOx to maintain accurate NO2 calculations. The NO2-to-NO converters can degrade over time and need to be replaced to get accurate total NOx measurement. In this study, Infra-red Laser Absorption Modulation (IRLAMTM) technology, which is an advanced QCL-IR spectroscopy proposed in the previous study [1], is used to measure NO and NO2 simultaneously in the exhaust gas of light-duty vehicles. This approach offers several advantages such as direct measurement of both NO and NO2 without a NO2-to-NO converter. The primary objective of this study is to compare IRLAM technology with conventional CLD by collecting a statistically significant set of certification-quality NOx emissions data in compliance with the requirements of 40 CFR 1065 from diluted exhaust of a MY2024 SULEV light-duty vehicles during certification testing. The results demonstrate no statistically significant difference between the measurements obtained from the two methodologies, establishing IRLAM as a suitable candidate for an alternate procedure for NOx measurement during certification testing. The t-values for all duty cycle populations were consistently below the critical t-values at both 90% and 95% confidence intervals. The f-test values for all duty cycle populations were consistently lower than the critical f-values at both 90% and 95% confidence intervals.
Rahman, Montajir, Nevius, Tim, Israel, Joshua, Hara, Kenji, Nagura, Naoki
Overview of Current Developments of Pre-Chamber Spark Plugs for Passenger Car Applications2025-24-01529/7/2025
The internal combustion engine (ICE) is projected to remain the dominant technology in the transport sector over the short to medium term, and there exists significant potential for further improvements in fuel economy and emission reductions. One promising approach to enhancing the efficiency of spark ignition engines is the implementation of passive pre-chamber spark plugs. The primary advantages of pre-chamber-initiated combustion include the mitigation of knocking, an increase in in-cylinder turbulence, and a combustion process that is both faster and more stable compared to that achieved with conventional J-gap spark plugs. Additionally, the higher ignition energy provided by pre-chamber spark plugs enables operation under higher intake pressures, maintains similar exhaust gas recirculation rates, and supports leaner combustion conditions. These benefits are predominantly attributed to volumetric ignition via hot, reactive jets. However, the pre-chamber spark plug also presents several challenges. Its drawbacks include suboptimal cold-start behavior, difficulties in catalyst heating when accompanied by aggressive spark retard, and inferior low-load performance resulting from reduced charge motion, elevated residual gas concentrations within the pre-chamber, and increased wall heat transfer at low loads. Furthermore, the challenge of adequately heating the catalytic converter persists due to delayed ignition timing. In this study, various passive pre-chamber configurations were systematically investigated and evaluated based on key performance metrics. Engine operation was categorized into three specific regimes: catalyst heating on a cold engine (operated at 1200 rpm with an IMEP of 3 bar), the optimal efficiency point corresponding to a minimum brake specific fuel consumption (operated at 2000 rpm with an IMEP of 14 bar), and a high-speed load sweep conducted at 4000 rpm. The experimental campaign was executed in two phases, allowing for iterative design modifications informed by the findings of the initial phase. Ultimately, the optimized pre-chamber design successfully achieved a minimal specific exhaust heat flux (SEHF), maintained the desired combustion stability, and extended the high-load operating envelope up to an IMEP of 18.5 bar.
Korkmaz, Metin, Juressen, Sven Eric, Rößmann, Dominik, Kapus, Paul E., Pino, Sandro
Optimization of Combustion Efficiency and Conversion Efficiency of Catalytic Converter in Spark-Ignited Engine using Taguchi Methods Robust Optimization Technique for Flex Fuel Application2024-32-01234/18/2025
Flex fuel vehicles (FFV) can operate effectively from E5 (Gasoline 95%, ethanol 5%) fuel to E100 (Gasoline 0%, ethanol 100%) fuel. It is necessary to meet the performance, drivability, emission targets and regulatory requirements irrespective of fuel mixture combination. This research work focuses on optimizing the combustion efficiency and conversion efficiency of catalytic converter of a spark-ignited less than 200 cc engine for FFV using Taguchi methods robust optimization technique. The study employs an eight-step robust optimization approach to simultaneously minimize engine out emissions and maximize catalytic converter efficiency. Six control factors including type of fuel, catalyst heating rpm, lambda (excess-air ratio), injection end angle, lambda controller delay, and ignition timing are optimized. Four noise factors like compression ratio, clearance volume, catalyst noble metal loading, and catalyst aging are also considered. Through approximately 100 physical experiments on a chassis dynamometer, the impact of control factors on engine out emissions and conversion efficiency has been evaluated. Signal-to-noise (S/N) ratios has been calculated for THC and NOx engine-out emissions (combustion efficiency) and their conversion efficiency. Based on the S/N ratio, optimal levels has been chosen for different control factors. The study predicts significant gains in THC conversion and combustion efficiency while modest improvements for NOx conversion. Confirmation runs has been conducted to validate the prediction. The confirmation run yielded slightly lower gains when compared to prediction. The study acknowledges limitations due to control factor interactions but highlights the substantial reduction in experimentation time and effort compared to traditional EFI system calibration methods. Ultimately, the research demonstrates the effective application of robust optimization techniques to meet emission regulations for flex fuel vehicles without significantly increasing production costs. This approach streamlines the optimization process, reducing the number of experiments required and addressing production variations efficiently.
Vaidyanathan, Balaji, Arunkumar, Praveenkumar, Shunmugasundaram, Palani, Murugesan, Manickam, Jayajothijohnson, Vedhanayagam
Research on the Characteristics of an Integrated Thermoelectric Generation, Catalytic Conversion, and Noise Suppression System2025-01-70621/31/2025
In the context of global energy shortages and increasing environmental pollution, improving energy efficiency in automobiles has become a key area of research. Traditional internal combustion engines exhibit low energy conversion efficiency, with a significant portion of fuel energy wasted as exhaust heat. To address this issue, this paper proposes an integrated thermoelectric generation, catalytic conversion, and noise suppression system (ITGCMS) aimed at recovering waste heat from vehicle exhaust, while optimizing emissions and noise reduction through the combination of a catalytic converter and a muffler. A three-dimensional model was established using COMSOL software to thoroughly analyze the system's thermoelectric generation, catalytic conversion, and acoustic performance. The study found that Model B demonstrated the best thermoelectric performance, with an average surface temperature of 300.2°C and a more uniform temperature distribution across the thermoelectric modules. Additionally, Model B exhibited the highest catalytic conversion efficiency, with a flow velocity uniformity coefficient of 0.78 at the catalyst inlet, significantly outperforming the other models. Moreover, all three models showed effective noise reduction, particularly in the high-frequency range, and achieved better transmission loss across the entire frequency spectrum compared to traditional mufflers. Exhaust pressure loss increased with intake speed, but the differences between the models were minimal. Overall, Model B demonstrated the most comprehensive improvement in energy efficiency, emissions reduction, and noise optimization. This study provides a valuable theoretical basis and technical support for enhancing energy efficiency in the automotive industry, offering new directions for the future application of thermoelectric generation technology in vehicle exhaust systems.
Wu, Ji-Xin, Su, Chu-Qi, Wang, Yi-Ping, Yuan, Xiao-Hong, Liu, Xun
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 Conditions2024-37-00026/12/2024
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 catalytic converter. Rich pulses decomposing sulphur species adsorbed on Pd-Pt methane oxidation catalysts, enable efficient regeneration of heavily poisoned catalysts. A strategy similar to operation with rich pulses, but with a different motivation, is the use of high-frequency oscillations between lean and rich exhaust gas, so-called dithering, to improve pollutant conversion. A combination of a stoichiometric pulse while simultaneously dithering shows better results in recovery as well as emissions during regeneration than a pure rich pulse.
Tomin, Sebastian, Wagner, Uwe, Koch, Thomas
Catalytic Converter—An Integrated Approach to Reduce Carbon Dioxide Emission2024-01-50474/22/2024
Vehicle emissions, which are rising alarmingly quickly, are a significant contributor to the air pollution that results. Incomplete combustion, which results in the release of chemicals including carbon monoxide, hydrocarbons, and particulate matter, is the main cause of pollutants from vehicle emissions. However, CO2 contributes more than the aforementioned pollutants combined. Carbon dioxide is the main greenhouse gas that vehicles emit. For every liter of gasoline burned by vehicles, around 2,347 grams of carbon dioxide are released. Therefore, it’s important to reduce vehicle emissions of carbon dioxide. The ability of materials like zeolite and silicon dioxide to absorb CO2 is outstanding. These substances transform CO2 into their own non-polluting carbonate molecules. Zeolite, silicon dioxide, and calcium oxide are combined to form the scrubbing material in a ratio based on their increasing adsorption propensities, along with enough bentonite sand to bind the mixture.
Saravanakumar, L., Arunprasad, S.
Exhaust Slip-Stream Sampling System for Aftertreatment Device Testing2024-01-27034/9/2024
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 cost-effective determination of aftertreatment device effectiveness. This work documents the design and performance of an intermediary-scale (5-50 SLPM) setup to aid in the catalyst testing process. This is accomplished using a secondary exhaust branch to flow a variable percentage of exhaust from the main branch. The system siphons exhaust via a slip-stream approach driven by a venturi ejector, which is commonly used in automotive applications to dilute samples for emissions analysis. Instead, the pre-diluted flow from the ejector is routed through the catalyst, where post catalyst emissions testing occurs. The system is evaluated under a range of engine operating conditions with varied equivalence ratio and intake pressures to affect exhaust out temperatures / catalyst inlet temperature which is critical for testing catalyst activation. Emissions are recorded in both the main and secondary branch with no aftertreatment device installed to verify compositional parity. Initial results show that the two branches produce self-similar engine-out emissions, but with the ability to scale flow and modulate temperature through the secondary catalyst testing branch.
Loprete, Jason, Ristow Hadlich, Rodrigo, Sirna, Amanda, Assanis, Dimitris, Mon, Tala, Kyriakidou, Eleni
Reducing Emissions from Lean-Burn Hydrogen Combustion Engines Using a State-of-the-Art Oxidation Catalyst and a VWTi-Based SCR Catalyst: Potentials and Challenges2024-01-26344/9/2024
Hydrogen (H2) is commonly considered as one of the most promising carbon-free energy carriers allowing for a decarbonization of combustion applications, for instance by retrofitting of conventional diesel internal combustion engines (ICEs). Although modern H2-ICEs emit only comparably low levels of nitrogen oxides (NOx), efficient catalytic converters are mandatory for exhaust gas after-treatment in order to establish near-zero emission applications. In this context, the present study evaluates the performance of a commercial state-of-the-art oxidation catalyst (OC) and of a catalyst for selective catalytic reduction (SCR) that are typically used for emission reduction from diesel exhausts under conditions representative for H2-fueled ICEs, namely oxygen-rich exhausts with high water vapor levels, comparably low temperatures, and potentially considerable levels of unburnt H2. Herein, the OC is supposed to convert H2 slippage, which can occur due to incomplete combustion, and to oxidize NO to NO2, which enables an efficient NOx removal over the SCR catalyst. While the vanadia-based SCR catalyst was barely affected by high water vapor levels, the presence of H2, or hydrothermal aging, H2O inhibited NO to NO2 oxidation over the OC and hydrothermal aging with 20 vol.-% H2O resulted in significant deactivation of the OC. At the cost of producing the inhibitor H2O and the greenhouse gas N2O, the presence of H2 facilitates a fast light-off due to temperature generation. These results underscore the importance of developing suitable catalyst operation strategies that account for efficient pollutant conversion and avoid secondary emissions formation.
Lott, Patrick, Schäfer, Kathrin, Deutschmann, Olaf, Werner, Manuel, Weinmann, Philipp, Zimmermann, Lisa, Toebben, Heike
Kinetic Model Development for Selective Catalytic Converter Integrated Particulate Filters2024-01-26314/9/2024
To meet the stringent NOx and particulate emissions requirements of Euro 6 and China 6 standard, Selective Catalyst Reduction (SCR) catalyst integrated with wall flow particulate filter (SCR-DPF) has been found to be an effective solution for the exhaust aftertreatment systems of diesel engines. NOx is reduced by ammonia generated from urea injection while the filter effectively traps and burns the particulate matter periodically in a process called regeneration. The engine control unit (ECU) effectively manages urea injection quantity, timing and soot burning frequency for the stable functioning of the SCR-DPF without impacting drivability. To control the NOx reduction and particulate regeneration process, the control unit uses lookup tables generated from extensive hardware testing to get the current soot load and NOx slip information of SCR-DPF as a function of main exhaust state variables. In the current work, engine dynamometer tests were conducted on a SCR-DPF at different operating conditions covering typical vehicle running conditions. The oxygen assisted and NO2 assisted soot burning efficiency of the SCR-DPF was measured with and without urea injection at different soot loads. The impact of ammonia on soot burning at different engine operating conditions was studied. Using the test data, a physics based 1-D reaction model was developed with NOx reduction and soot oxidation reactions. The detailed SCR chemistry includes reactions for ammonia adsorption/desorption, NO oxidation, NH3 oxidation, standard/fast/slow NOx reduction and N2O formation. The soot burning reaction kinetics is described by the oxidation of soot with NOx. The NOx reduction and soot regeneration efficiency predictions of the model were validated with test values measured at engine dynamometer conditions under various exhaust flow rate, temperature, and soot load conditions. This 1-D kinetic model can be applied to generate calibration look up tables for the SCR-DPF control system in the vehicle to identify the right soot burning protocol to achieve the target regeneration efficiency. Few of the other areas where the model can be applied are, exhaust aftertreatment (EAT) architectural evaluation, converter sizing, wash coat loading studies, urea injection strategy development and heater element controls optimizations. Compared to the conventional hardware test-based approach, this model-based virtual approach uses less test data thus resulting in faster product development cycle and reduces the testing in engine dynamometer and vehicles.
Kannan, Rajesh, Paramadhayalan, Thiyagarajan, Mital, Rahul, Gustafson, Erik, Edwards, David
Algorithm to Calibrate Catalytic Converter Simulation Light-Off Curve2024-01-26304/9/2024
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 and effort. Catalytic converter models require the specification of input conditions (i.e. temperature, flowrate, and species concentrations). Then they calculate the predicted exhaust gas composition by simulating the chemical reactions occurring within the catalyst. These simulations can then be calibrated and validated against experimental measurements. The chemical reaction rates in the model utilize an Arrhenius expression which includes two tunable variables, the pre-exponential factor (A), which is a measure of collision frequency, and the activation energy (E), which is a threshold to overcome for molecules to react. Calibration of these values often requires many iterations, checking the results and adjusting to eventually identify the best values. In this work, an optimization algorithm was developed to automatically tune these parameters to best simulate catalyst light-off data. This algorithm is presented. It has the potential to significantly reduce time in calibrating catalyst models.
Wilson, John Parley, DelVescovo, Dan
Simulation Methodology for Failure Analysis of Catalytic Converter Mounting on Commercial Vehicles2024-01-22474/9/2024
Catalytic converters have been considered as an integral part of the vehicle powertrain for over a decade now, their application along with the engines increased significantly with the constant evolution of emission standards. Recent regulations keep a strict control on the major four pollutants of engine exhaust gas, i.e., Carbon Monoxide (CO), Nitrogen Oxides (NOx), Hydrocarbons (HC) & Particulate Matter (PM), which demands a highly efficient aftertreatment system. Efforts are continuously being made to downsize the engine for better fuel economy and low emissions, this puts additional requirement of designing a compact aftertreatment system equipped with Diesel Oxidation Catalyst (DOC), Diesel Particulate Filter (DPF) and Selective Catalytic Reduction (SCR). Compact catalytic converters experience larger vibration force transferred from the vehicle and hence the durability of the product is significantly impacted. Vibration sources are a) Engine, b) Road Load, using a long flex pipe can contribute to the dampening of vibrations coming from engine but cannot prevent the vibrations transferred from the chassis. And it is very rare to use rubber-based isolator to decouple chassis vibration in a commercial vehicle because the heaviness of parts, packaging space constraints and cost increase reduce the benefit of having several isolators. Such components are extensively applied in light vehicle systems, where the packaging space is comparatively more, parts are lighter, and the system mass is distributed as compared to concentrated mass in commercial vehicles. Generally, the lead time for basic durability tests of aftertreatment systems for commercial vehicles is around one week, including the test setup and calibration. It is a bottleneck in the development process, so engineers are highly motivated to develop simulation models that are validated with high accuracy to replace the time-consuming testing phase. The authors propose a Finite Element Analysis (FEA) model in this paper to evaluate the failure limit of mounting belts used to fix an aftertreatment device weighing over 100kg on the vehicle frame. The model calculates the contact force for the belts and uses it to predict the failure point of the holding force. This simulation model was validated against the vibration tests conducted on a shaker bench capable of generating acceleration level of 25G at a frequency of 20Hz uniaxially for a system weighing nearly 100kg. It is important to note that the focus of this model is on the mounting bracket clamps and their functionality for holding the catalytic converter. Hence the objective is to check the frictional capability, where in even at high acceleration force the system should not move relative to the clamp. The acceleration force and frequency are the input boundary conditions, which are controlled on the test bench using acceleration sensors, and the output is the frictional capability which is monitored by observing slippage of the system.
Gupta, Bipin, Li, Jiangong, Singaravel, Vinothkumar
GPF: An Effective Technology to Minimize Two Wheeler (2Wh) Particulate Emission2024-26-01401/16/2024
India is the world’s largest two-wheeler (2Wh) market. With the proportion of its middle class rapidly rising, 2Wh sales and the resulting emissions, are expected to grow exponentially. The decision to leap-frog from BSIV to BSVI emission norms shows India’s commitment to clean up its atmosphere. As of now, the regulation mandates Gaseous Pollutant (CO, HC, NOx) emission limits for all 2Whs and a particulate limit (PM & PN) for 2Whs powered by Direct Injection (DI) engines. Most of the 2Whs manufactured in India are powered by gasoline engines using the Port Fuel Injection (PFI) technology, and hence by definition particulate emission limits do not apply to them. Particulates when inhaled - especially of the ultrafine sizes capable of entering the blood stream - pose a serious health risk. This was the primary motivation to investigate the particulate emission levels of the 2Whs, which as on date, do not come under the purview of BSVI regulation. A study was conducted selecting a motorcycle each from two different vehicle categories – Class 1 and Class 2-1 – as defined under the Indian 2Wh regulation. In the first phase of testing, emissions from both motorcycles in “as is” condition, were measured under WMTC conditions. While the CVS diluted PN emission for the Class 1 motorcycle was found to be 2.2 X 1011 #/km, the same for the Class 2-1 motorcycle was even higher at 7.0 X 1011 #/km. In the second phase, the emission control system for each of the motorcycles was retrofitted with a Gasoline Particulate Filter (GPF) as an “add-on”, downstream to the “as is” catalytic converter system, and emission tests were repeated. Addition of the GPF reduced the particulate emissions by more than 80%. Thus, the study shows that the particulate emissions from the 2Whs are high enough to adversely impact air quality and advanced emission control solutions like the GPF can effectively minimize the 2Wh particulate emissions.
Bhimavarapu, Aditya, Singh, Sunil Kumar, Kataria, Rohit, Rose, Dominik, Boger, Thorsten
Effect of Diesel-Ethanol Blends on the Performance and Emissions of a CI Diesel Engine Suitable for Stationary Application2024-26-00781/16/2024
Ethanol, being a bio-based alternate fuel, is one of the most promising fuels for blending with diesel for emissions reduction, primarily due to its oxygenated nature, which results in lower carbon content than diesel. Under this research work, various ethanol-diesel (ED) blends have been developed for investigation. Additives were developed to address the problem of corrosion, cetane number reduction, and blend stability. A detailed physico-chemical characterization was performed, and all the blends were subjected to the stability test at various temperatures. Subsequently, detailed experiments were conducted to understand ethanol- blended diesel fuels combustion and engine-out emission characteristics. The performance of the tested engine with ethanol blending remained at par with the baseline diesel; however, a reduction in the PM and gaseous emissions established ethanol blend as a favourable fuel solution for the tested CI engine. Experimental results indicate that blending ethanol in diesel leads to 7% reduction of the cycle NOx emissions (for 20% blend) as compared to the baseline diesel; however, HC and CO were observed to have an increasing trend. A significant reduction of PM (~32%) was observed with 20% ethanol blending. The thermal efficiency improved by 6% maximum with 20% ethanol blend at full load. A meticulous analysis of the combustion data indicated no significant change in the engine in-cylinder pressure values and the start of injection from baseline diesel to ethanol blends at full load condition. However, at part load operation (at and below 50% load), peak firing pressure was reduced up to 6%, and the start of injection and combustion got retarded by ~2 deg crank angle. 5% ethanol blend came out as optimum for quick implementation in the existing engine perspective. Nonetheless the additional HC/CO emissions might have to be dealt with by a catalytic converter.
Garg, Rahul, Mukherjee, Nalini, Viswanath, Chithra, Choudhary, Vasu, Newalkar, Bharat, Nene, Devendra, Kusumba, Manoj
An Experimental Approach Towards Sustainable Solution for Material Recycling of ELV Plastic Bumpers and EV Batteries2024-26-01641/16/2024
A general automotive car is majorly composed of high strength steel (6%), other steel (50%), Iron (15%), Plastics (7%), Aluminum (4%) and others (Rubber, Glass, Textile) about 18%. End-of-life vehicles (ELVs) are a significant source of waste and pollution in the automotive industry. Recycling ELVs, particularly their plastic components, Li-ion batteries, catalytic converters, and critical technology components such as alternators, semi-conductor chips, and high tensile strength steel can reduce their environmental impact and conserve valuable raw materials. The paper conducts a SWOT analysis and a life cycle assessment (LCA) to evaluate the long-term viability and potential of ELV recycling, environmental impact, and carbon footprint. This paper examines the current state and challenges of ELV recycling in India and proposes a sustainable recycling solution for waste bumpers that includes paint removal, modification, reprocessing & recovery of precious metals from xEV Li-ion batteries. i Plastic recycling – Mainly PP from bumpers and other components. ii Precious metals recovery – Lithium, Cobalt, Nickel, Mn etc. Based on pilot line experiment sustainable recycling solution was established and validated through lab testing to compare the changes in physical properties. The paper also discusses the progress and challenges of achieving Carbon neutrality and circular economy objectives in the automotive industry and provides insights on sustainable material developments like e.g., long cellulose fiber reinforced thermoplastic for bumpers, reusability of raw materials in automobile parts manufacturing without compromising on quality requirements & provides data for rational decision-making and policy-making for ELV recycling in India.
Baviskar, Ajay, Khera, Pankaj, Telgote, Ashish, Dhuria, Himanshu, Sharma, Amit
Three Way Catalyst with Faster Light-Off Substrates – A Promising Approach to Reduce Tailpipe Emissions2024-26-01421/16/2024
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 energy is used by the turbine to power the compressor) leading to lower exhaust gas temperatures, specifically at ambient/cold starts. In order to achieve better emission performance, an innovative approach is needed to attain quicker catalyst “light-off” as any change in only the PGM material content/composition may not yield an optimum solution. Though in-cylinder based strategies to increase EGT exist, they impose an additional fuel penalty along with issues like oil dilution. A much better way – avoiding the issues above - to improve the EGT profile is to reduce the thermal inertia of the catalytic converter. This is the idea behind introducing high-porosity substrates. A new Corning© FLORA© substrate with a higher porosity (55%) compared to the standard substrates (35%) was adopted as the primary substrate (CC1) in a twin brick catalyst design. Higher porosity reduces the thermal inertia of the substrate which in turn aids in rapid catalyst temperature rise and faster light-off. The advanced FLORA® substrate when combined with key contributor’s improvements on catalytic converter design and engine calibration strategy on 1.2 L MPFI RevotronTM engine, resulted in an improved emissions performance even with a lower PGM content. A reduction of 10 to 30% in regulated pollutants was demonstrated with an approximately 10% lower PGM material loading. The paper describes the multipronged approach taken here to tackle the cold start emissions - redesign of the close coupled catalyst, innovative calibration methodology & the introduction of the high porosity substrate popularly known as FLORA®. The work was conducted on a Tata Motors passenger car powered by a 1.2L MPFI RevotronTM gasoline engine that successfully met the BS6 Stage II emission norms.
Kale, Vishal Maruti, M, Ravisankar, Hosur, Viswanatha, Sridhar, S, Bhimavarapu, Aditya, Lende, Nilesh Ashok, Rose, Dominik, Tao, Tinghong
How to Accomplish a More Sustainable Internal Combustion Engine Using Life Cycle Analysis: A Demo2023-01-165710/31/2023
The Sustainable Development Goals were adopted by all United Nation Member States in 2015 to ensure a sustainable planet and improved living conditions for everyone, everywhere. The light duty vehicle (LDV) fleet has exceeded one billion, with most vehicles being powered by internal combustion engines. Transportation is responsible for 60% of global fossil oil consumption. Air pollution is a large problem in cities often attributed to road transport. Vehicles comprise of over 70 material categories, indicating the complexity of sustainable material management. A hypothesis was established, that a sustainable engine (SE) could significantly reduce the environmental impact of transportation and, be realized by combining available technologies. A life cycle analysis was conducted on a 145 kW 2-litre Miller-cycle gasoline 48V-mild-hybrid engine with EU6d exhaust aftertreatment system (EATS), assessing seven mid-point categories. The environmental impacts were used to establish sustainable lifecycle target levels for carbon dioxide equivalent (CO2eq), carbon monoxide (CO), nitrous oxides (NOx) and total-hydrocarbons (THC). A system solution was designed and manufactured to meet the proposed targets. Recycled materials have been applied and verified to multiple components, realizing a 71% reduction in cradle-to-gate Climate Change (CC) impact for the complete engine. An exhaust aftertreatment system (EATS) was developed and tested via a method using a vehicle emissions test cycle adopted on a dynamic engine bench. Considerations were performed for the possibility to use recycled platinum group materials (PGMs) in the catalytic converter. Air pollutant levels were reduced over 90% for the first 390s of the Worldwide Harmonized Light Vehicles Test Procedure (WLTP). A renewable gasoline was tested achieving a 65% lower fuel life cycle climate change impact. Over the complete engine and fuel life cycle a 61% reduction in climate change impact was achieved. The method and demonstrated technology provide insights into a sustainable system solution for an internal combustion engine. Challenges were identified and discussed in relation to primary data collection, establishing circular supply chains and quantifying targets.
Dudley, Joshua Paul, Laurell, Mats, Thuve, Christoffer, Klövmark, Henrik
Ensemble Empirical Mode Decomposition for Characterising Exhaust Nano-Scale Particle Emissions of a Turbocharged Gasoline Power Unit2023-01-166510/31/2023
This paper presents a method for analysing the characteristics of nano-scale particles emitted from a 1.6 Litre, 4-stroke, gasoline direct injection (GDI) and turbocharged spark ignition engine fitted with a three-way catalytic converter. Ensemble Empirical Mode Decomposition (EEMD) is employed in this work to decompose the nano-scale particle size spectrums obtained using a differential mobility spectrometer (DMS) into Intrinsic Mode Functions (IMF). Fast Fourier Transform (FFT) is then applied to each IMF to compute its frequency content. The results show a strong correlation between the IMFs of specific particle ranges and the IMFs of the total particle count at various speed and load operating conditions. Hence, it is possible to characterise the influence of specific nano-scale particle ranges on the total particulate matter signal by analysing the frequency components of its IMFs using the EEMD-FFT method. This approach can provide a useful insight for developing a control strategy for reducing nano-scale particle emissions of a GDI engine. The present work details the systematic methodology followed for using EEMD in combination with FFT to analyse the spectrums of nano-scale particulate matter emissions.
El Yacoubi, Ismail, Samuel, Stephen
GT-Suite Modeling of Thermal Barrier Coatings in a Multi-Cylinder Turbocharged DISI Engine for Catalyst Light-Off Delay Improvement2023-01-160210/31/2023
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 expensive. In this work, a reduced-order system-level modeling methodology in GT-Suite was leveraged to evaluate TBCs on exhaust ports, manifold, and runners. A multi-cylinder turbocharged DISI engine was modeled in GT-Suite, with capability to model a layer of TBC on internal surfaces. The model was calibrated using measured data from steady state operating conditions due to lack of transient cold start data. Following the TBC analysis, a theoretical study to infer the effects of turbocharger casing heat loss on the catalyst warm-up was performed. The TBCs showed no tangible benefit in the catalyst light-off delay when applied on the combustion chamber walls but showed a 20-second faster catalyst light-off when an 800-micron thick TBC was applied on the exhaust flow path walls (exhaust ports, manifold and runners). The turbocharger casing/housing heat transfer was shown to have a considerable effect on the catalyst light-off delay. An additive benefit to the catalyst light-off delay was achieved by insulating the combustion chamber walls, the exhaust flow path walls, and the turbocharger casing together which was predicted to be 25 seconds faster than the baseline.
Ravikumar, Avinash, Bhatt, Ankur, Gainey, Brian, Lawler, Benjamin
Methanol (M85) Port-Fuel-Injected Spark Ignition Motorcycle Engine Development—Part 2: Dynamic Performance, Transient Emissions, and Catalytic Converter Effectiveness03-17-03-001910/27/2023
Methanol is emerging as an alternate internal combustion engine fuel. It is getting attention in countries such as China and India as an emerging transport fuel. Using methanol in spark ignition engines is easier and more economical than in compression ignition engines via the blending approach. M85 (85% v/v methanol and 15% v/v gasoline) is one of the preferred blends with the highest methanol concentration. However, its physicochemical properties significantly differ from gasoline, leading to challenges in operating existing vehicles. This experimental study addresses the challenges such as cold-start operation and poor throttle response of M85-fueled motorcycle using a port fuel injection engine. In this study, M85-fueled motorcycle prototype is developed with superior performance, similar/better drivability, and lower emissions than a gasoline-fueled port-fuel-injected motorcycle. An open electronic control unit was installed using suitable wiring harness/sensors and actuators to control the engine. Then the motorcycle electronic control unit was calibrated for transient operations on a chassis dynamometer. The motorcycle was tested under road load simulation and wide-open throttle conditions on the chassis dynamometer to compare its performance with a baseline gasoline-fueled motorcycle. Evaluation parameters included power at wheels, maximum vehicle speed, and time-based and speed-based acceleration characteristics. Transient emissions were evaluated following the Indian driving cycle protocols. The effectiveness of the catalytic converter for M85 fueling was assessed by comparing various emissions upstream and downstream of the catalytic converter. M85-fueled motorcycle generated higher power at wheels and similar maximum speeds as baseline gasoline-fueled motorcycle. Fine-tuned M85-fueled motorcycle exhibited superior acceleration characteristics over baseline gasoline-fueled motorcycle, indicating that an appropriate tuning strategy could tackle the issue of “drivability.” M85-fueled motorcycle emitted lower carbon monoxide and hydrocarbon during the warm-up cycles in the Indian driving cycle protocol. The inherent fuel oxygen of M85 enhanced the carbon monoxide–carbon dioxide conversion, reducing carbon monoxide emissions in the engine exhaust. The existing catalytic converter was also suitable for M85 fueling since the hydrocarbon, nitric oxide, and carbon monoxide emissions were effectively reduced downstream of the catalytic converter in all test conditions.
Agarwal, Avinash, Yadav, Omkar, Valera, Hardikk
Simulation of Temperatures of Three Way Catalytic Converter for Motorcycles at Higher Temperatures2023-01-181510/24/2023
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 flow in the exhaust pipe was also analyzed using the 3D-CFD. As the last step for estimation of temperatures in the 3-way catalysis, the reactions in the catalysis were analyzed to take into account the heat generated by the oxidation of unburnt hydrocarbons promoted by the catalysis. The correlation between the estimation by this method and the actual measurement was taken in the five models having various engine configurations such as the number of cylinders and cooling methods, and vehicle configurations such as the scooter and the motorcycle. It has consequently been confirmed that this method allows estimation of temperatures in degrees Celsius inside the three way catalytic converter at higher temperatures as accurately as a maximum error of 5%. Thus, enabled is an accurate evaluation of parts layout to satisfy the heat resistance requirements of the three way catalytic converter at higher temperatures.
Shigeno, GENKI, Fujita, Shinji, yogo, toyoyuki
Simulation of CNG Engine in Agriculture Vehicles. Part 2: Coupled Engine and Exhaust Gas Aftertreatment Simulations Using a Detailed TWC Model2023-24-01128/28/2023
In more or less all aspects of life and in all sectors, there is a generalized global demand to reduce greenhouse gas (GHG) emissions, leading to the tightening and expansion of existing emissions regulations. Currently, non-road engines manufacturers are facing updates such as, among others, US Tier 5 (2028), European Stage V (2019/2020), and China Non-Road Stage IV (in phases between 2023 and 2026). For on-road applications, updates of Euro VII (2025), China VI (2021), and California Low NOx Program (2024) are planned. These new laws demand significant reductions in nitrogen oxides (NOx) and particulate matter (PM) emissions from heavy-duty vehicles. When equipped with an appropriate exhaust aftertreatment system, natural gas engines are a promising technology to meet the new emission standards. Gas engines require an appropriate aftertreatment technology to mitigate additional GHG releases as natural gas engines have challenges with methane (CH4) emissions that have 28 times more global warming potential compared to CO2. Under stoichiometric conditions a three-way catalytic converter (TWC - stoichiometric combustion) can be used to effectively reduce emissions of harmful pollutants such as nitrogen oxides and carbon monoxide (CO) as well as GHG like methane. The aim of the present study is to understand the performance of the catalytic converter in function of the engine operation and coolant temperature in order to optimize the catalyst operating conditions. Different cooling temperatures are chosen as the initial device temperature highly affects the level of warm up emissions such that low coolant temperatures entail high emissions. In order to investigate the catalyst performance, experimental and virtual transient engine emissions are coupled with a TWC model to predict tail-pipe emissions at transient operating conditions. Engine experiments are conducted at two initial engine coolant temperatures (10°C and 25°C) to study the effects on the Non-Road Transient Cycle (NRTC) emissions. Engine simulations of combustion and emissions with acceptable accuracy and with low computational effort are developed using the Stochastic Reactor Model (SRM). Catalyst simulations are performed using a 1D catalytic converter model including detailed gas and surface chemistry. The initial section covers essential aspects including the engine setup, definition of the engine test cycle, and the TWC properties and setup. Subsequently, the study introduces the transient SI-SRM, 1D catalyst model, and kinetic model for the TWC. The TWC model is used for the validation of a NRTC at different coolant temperatures (10°C and 25°C) during engine start. Moving forward, the next section includes the coupling of the TWC model with measured engine emissions. Finally, a virtual engine parameter variation has been performed and coupled with TWC simulations to investigate the performance of the engine beyond the experimental campaign. Various engine operating conditions (lambda variation for this paper) are virtually investigated, and the performance of the engine can be extrapolated. The presented virtual development approach allows comprehensive emission evaluations during the initial stages of engine prototype development.
Leon de Syniawa, Larisa, Siddareddy, Reddy Babu, Prehn, Sascha, Guenther, Vivien, Franken, Tim, Buchholz, Bert, Mauß, Fabian
Simulative Estimation of a Super-High-Efficiency Stoichiometric Gasoline Engine with GT-Power2023-24-01298/28/2023
This paper presents a concept of a high efficiency stoichiometric gasoline engine first published in [1]. The engine is modelled in GT-Power and uses the FKFS UserCylinder. All effects and components that cannot be modelled with these two software modules are estimated by tuning the model parameters to achieve the desired effects. The basic concept of the engine for the model was first published in [2] and [3] by Negüs et al. and includes engine friction reduction, improved turbocharger efficiency, variable compression ratio and variable valve train to allow Miller-Cycle and zero-cam profile cylinder deactivation capability. To further increase efficiency of the engine, measures are introduced to increase knock resistance. The first measure includes a pre-chamber spark plug, which proved to significantly reduce combustion duration [4] and thus the likelihood of knock due to rapid combustion of the fuel mass. The second measure is a high-turbulence tumble concept with a switchable tumble flap to further shorten the burn time. The third measure is high-pressure injection [5], feeding fuel close to TDC of the compression stroke. This slows down the pre-knock reactions and further reduces the engine's knock probability. The engine uses an electrically heated three-way catalytic converter and a gasoline particle filter. To make the simulation for the engine comparable, it is integrated into a P0-hybrid-electric powertrain and simulated in a comparative analysis with a low-cost engine for four representative drive cycles.
Stoll, Tobias, Kulzer, Andre Casal, Berner, Hans-Juergen
A Mid-Infrared Laser Absorption Sensor for Gas Temperature and Carbon Monoxide Mole Fraction Measurements at 15 kHz in Engine-Out Gasoline Vehicle Exhaust03-17-01-00027/21/2023
Quantifying exhaust gas composition and temperature in vehicles with internal combustion engines (ICEs) is crucial to understanding and reducing emissions during transient engine operation. This is particularly important before the catalytic converter system lights off (i.e., during cold start). Most commercially available gas analyzers and temperature sensors are far too slow to measure these quantities on the timescale of individual cylinder-firing events, thus faster sensors are needed. A two-color mid-infrared (MIR) laser absorption spectroscopy (LAS) sensor for gas temperature and carbon monoxide (CO) mole fraction was developed and applied to address this technology gap. Two quantum cascade lasers (QCLs) were fiber coupled into one single-mode fiber to facilitate optical access in the test vehicle exhaust. The QCLs were time-multiplexed in order to scan across two CO absorption transitions near 2013 and 2060 cm–1 at 15 kHz. This enabled in situ measurements of temperature and CO mole fraction to be acquired at 15 kHz in the engine-out exhaust of a research vehicle (modified production vehicle) with an 8-cylinder gasoline ICE. Three different vehicle tests were characterized with the LAS sensor as follows: (1) cold start with engine idle, (2) warm start with a drive cycle on a chassis dynamometer, and (3) hot start with a drive cycle on a chassis dynamometer. The measurements obtained from the LAS sensor had a time resolution that was three orders of magnitude faster than that of thermocouple and gas analyzer data acquired at the Ford vehicle emissions research laboratory (VERL) in Dearborn, Michigan. This enabled the LAS sensor to resolve high-speed engine dynamics and exhaust gas transients, which the conventional instrumentation could not, thereby providing valuable insight into the evolution of ICE emissions during transient engine operation.
Stiborek, Joshua W., Tancin, Ryan J., Kempema, Nathan J., Szente, Joseph J., Loos, Michael J., Goldenstein, Christopher S.
Influence of Heating Measures on Urea Processing2023-01-50376/26/2023
With the introduction of the emission legislation Euro VI for commercial vehicles (CVs), selective catalytic reduction (SCR) with urea water solution (UWS) as the reducing agent has become a standard to minimize the nitrogen oxides (NOx) emissions from internal combustion engines. The urea processing and mixing unit has been developed and optimized in order to avoid deposit formation and ensure a high level of urea processing over the whole operation range, especially at lower temperatures. However, there are physical limits to the conversion of urea in conventional processing units during very low engine operating conditions. With the EHC Fractal Heater, Purem by Eberspächer has developed a heating measure that, in addition to its main function of accelerating the light-off of catalytic converters, also comes with the possibility of improving the UWS processing, especially under these low-load conditions.
Többen, Heike, Weinmann, Philipp
Model-Free State Estimation Using Subspace Identification and Kalman Filter2023-01-03654/11/2023
The model-based design is very much prominent in the vehicle level control system design and state estimation algorithms. It gives the edge to understand and interpret the dynamic systems. Three-way catalytic converter is a thermo-chemical device to convert the toxic oxides into carbon dioxide and water vapor, during this conversion reactions it generates the heat over the catalyst surface. Detailed chemical and thermal model of the catalyst will be able to predict the conversion efficiency, state of stored oxygen (SoX) and oxygen storage capacity (OSC). As the catalyst get aged, the reaction rates of conversion reactions deteriorate, in results the temperature dynamics also varies which wanes the exothermic heat. In this work, a novel perspective is presented to capture the behavior of SoX and health of the catalytic converter using thermal model analysis of TWC. An equivalent second order multi input single output (MISO) linear sub-space model is identified for the complex detailed thermal model. A second order MISO system is obtained using measured temperature sensor signals across the device. Recursive least square method will be updating the system parameters online then Kalman filter is employed for state estimation. Joint estimation of the hidden state is tested and validated on urban drive cycle with differently aged catalytic converters.
Mandloi, Deepak, Sahu, Prachi, Bagade, Monika Jayprakash, Das, Himadri
A Method to Reduce Cold Start Emissions while Shortening Fast Idle Catalyst Light-off Time2023-01-02474/11/2023
For vehicles with internal combustion engines, tailpipe emissions heavily rely on the aftertreatment system, typically a catalytic converter. Modern three-way catalysts (TWC) can very effectively convert the unburnt hydrocarbons (HC), CO, and NOx into non-harmful gases such as H2O, CO2, and N2 when the catalyst brick reaches a relatively high temperature. However, before that catalyst light-off temperature is reached, the emissions conversion efficiency is low, leading to high tailpipe emissions. Due to this light-off temperature requirement of the catalytic converter, the emissions from the engine cold-start period contributes a significant portion of vehicle overall emissions. One of the major reasons for high emissions during cold start is low combustion chamber wall temperatures, lower than the initial boiling temperature of gasoline fuel. This results in fuel film formation, and significantly incomplete evaporation prior to combustion. In this study, an approach to increase the fuel evaporation rate and fuel-air mixing for reduced cold start emissions while attaining fast catalyst light-off time is explored by using CVVD (continuously variable valve duration) & CVVT (continuously variable valve timing) mechanisms for both the intake and exhaust valvetrains. Early exhaust valve closing (EVC) and late intake valve opening (IVO) can be used to create negative valve overlap (NVO) for trapping hot exhaust gas residuals to facilitate fuel vaporization and reduce engine-out emissions during the engine cold-start and warm-up periods. In addition, early exhaust valve opening (EVO) timing can be employed to ensure fast catalyst light-off time. In this paper, a spark-ignited combustion engine is considered, and the engine-out emissions during the cold fast-idle period are studied. Both numerical simulations and engine testing are conducted to analyze the potential improvement of fuel vaporization and cold start emissions reductions with the proposed NVO approach.
Zhu, Shengrong, Hollowell, Jeffrey, Ha, Kyoung-Pyo, Fantin, Nicholas, Shirley, Mark
Advanced Low Mass Ceramic Substrate for improved Cold Start Performance Targeting PROCONVE L8 Light-Duty Emissions Regulations2022-36-00272/10/2023
Brazilian Emissions Regulations are getting tighter in the coming years. With PROCONVE L7 in Jan-2023 and PROCONVE L8 in 2025, regulated emissions limits will significantly decrease, such as, the NMOG + NOx standard from 130 mg/km (PL6) to 50 mg/km (PL8). This challenge will necessitate better aftertreatment performance, with expected increases the catalytic converter PGM content, and consequently higher system cost. It is understood that approximately 75% of an engine’s gaseous pollutants occur during the first few seconds after a cold start, thus it is crucial to promote the emissions conversion performance during that period. One approach is to decrease the heat capacity of the catalytic system, which can be done by utilizing cordierite substrates with thinner walls or an increased material porosity. CORNING has developed an innovative technology to substantially raise the porosity of conventional ultra-thin wall substrates from 35% to 55%, while maintaining their strength. This advanced low mass design allows for a reduction of the substrate volumetric heat capacity, enabling a faster thermal response for improved catalytic function and lower tailpipe emissions. With an aim to understand the performance of the advanced low mass substrate technology within Brazil’s traditional ethanol-fuel environment, an emissions test program was performed using a modern 1.0L turbo-charged E100 engine on a transient dynamometer. The aftertreatment system consisted of 2 catalytic converters; a 1.26L converter in the closed-coupled position, and a 1.0L converter in the underfloor position. The focus of the study was to evaluate the substrate impact in the close-coupled catalyst, while the maintaining the underfloor catalyst. The baseline reference was a standard 750/2 substrate with a conventional TWC formulation in the close-coupled position. To explore the emission and cost reduction potential, samples of the low mass, high porosity substrates were coated and tested with the same TWC formulation, as well as, with reduced precious metal content. Prior to testing, all samples were oven-aged at 900°C to represent an end-of-life condition. Emission testing procedures followed the USEPA FTP75 protocols. Results from this study confirmed that the advanced low mass substrate can significantly reduce emissions (THC emissions by roughly 13%) or allow for lower PGM loadings without emissions penalty.
Petrini Fogaça, Rômulo, Urbani Amadei, Gabriel, L. Warkins, Jason, A. Craig, Angus
Exhaust Gas Analysis of Various Potential GHG-Neutral Synthetic Fuels and Gasoline/Alkylate-Blends Including Variable Injection Timings2022-01-10858/30/2022
The exhaust gas composition of several potential greenhouse gas neutral C1-based synthetic fuels and gasoline/alkylate-blends are compared to each other and benchmarked against gasoline. The search for sustainable alternatives to conventional fossil fuels is still ongoing. Ideally, the exhaust gas of such an alternative should not deteriorate the environment’s air quality. The testing conducted here is focused on automotive application. However, promising fuel candidates could also be used elsewhere. The gasoline/alkylate blends investigated contain various percentages of dimethyl carbonate (DMC) or methyl formate (MeFo). Various methanol-MeFo mixtures as well as a 65 vol% DMC+ 35 vol% MeFo mixture are investigated as examples for a pure synthetic fuel. The tests are carried out on a single-cylinder spark ignition research engine. To analyze the gaseous emissions a state-of-the-art FTIR, equipped with a specifically tailored evaluation method, and conventional exhaust gas analyzers are used. In addition, particle emissions with 10 and 23 nm cut-off size are measured. Specific focus is set on the start of injection timing influence. Several possible injection-timing optimizations for a pure synthetic fuel are shown. The adequate functionality of a non-adapted three-way catalytic converter (TWC) is confirmed for such an oxygenated fuel. The working TWC validates the detected stoichiometric air-fuel ratio. Further, it was shown that unburned or only partially burned DMC and MeFo are converted by the TWC over a wide air-fuel ratio range, even up to an air-fuel equivalence ratio of 1.5.
Kraus, Christoph, Fitz, Patrick, Fellner, Felix, Härtl, Martin, Jaensch, Malte
Cycle-To-Cycle Effects and Knock Prediction using Spark Induced Disturbances on a PFI Methanol HD SI Engine2022-01-10678/30/2022
Stoichiometric operation of a Port Fueled Injection (PFI) Spark-Ignited (SI) engine with a three-way catalytic converter offers excellent CO2 reduction when run on renewable fuel. The main drawbacks with stoichiometric operation are the increased knock propensity, high exhaust temperature and reduced efficiency. Knock is typically mitigated with a reactive knock controller, with retarded ignition timing whenever knock is detected and the timing then slowly advanced until knock is detected again. This will cause some cycles to operate with non-ideal ignition timing. The current work evaluates the possibility to predict knock using the measured and modelled temperatures at Inlet Valve Closing (IVC) and Top Dead Center (TDC). Feedback effects are studied beyond steady state operation by using induced ignition timing disturbances. The approach is based on a deterministic controller where the timing is advanced beyond steady state knock limited operation or vastly retarded to produce warmer residuals in the following cycle. The results indicate that for the current engine there is no feedback effect. Chemical kinetics explains the lack of feedback due to lack of reactivity at TDC conditions. The chemical kinetic study in conjunction with the established auto ignition models described by Livengood-Wu reveals that the charge mixture entered a region of reactivity around the 50% burned point. It was also found that knocking and non-knocking cycles can have overlapping thermodynamic trajectories but for knocking cycles there is less dispersion. The study uses a solver which corrects the IVC temperature to minimize the error between observed knock onset and the point where the Livengood-Wu expression reaches unity for a knocking cycle. The corrections were found to have a correlation to uncaptured evaporation effects. Combined experimental and modelling results were in line with previous findings, namely that cycle-to-cycle combustion variations are plausibly explained by early flame propagation.
Lius, Andreas, Cronhjort, Andreas, Stenlaas, Ola
Evaluation of Cylinder State Estimator using Fuel Evaporation Assessment in a PFI Methanol HD SI Engine2022-01-10658/30/2022
Modern spark-ignited (SI) engines offer excellent emission reduction when operated with a stoichiometric mixture and a three-way catalytic converter. A challenge with stoichiometric compared to diluted operation is the knock propensity due to the high reactivity of the mixture. This limits the compression ratio, thus reducing engine efficiency and increasing exhaust temperature. The current work evaluated a model of conditions at inlet valve closing (IVC) and top dead center (TDC) for steady state operation. The IVC temperature model is achieved by a cycle-to-cycle resolved residual gas fraction estimator. Due to the potential charge cooling effect from methanol, a method was proposed to determine the fraction of fuel sourced from a wall film. Determining the level of charge cooling is important as it heavily impacts the IVC and TDC temperatures. This method is based on air flow measurement and comparing information from the compression event during a transient from fired to motored conditions, while keeping the intake density constant. Experiments were conducted on a high compression ratio (14:1) heavy duty (HD) single cylinder research engine (SCRE). The fuel was methanol, injected via port fuel injection (PFI). The results indicate that the latent heat of vaporization of the fuel is far from being fully utilized, due to inherent design limitations of the intake system. It was also found that charge cooling could be altered by utilizing features of the swirl optimized cylinder head, while the same features also hinted that some stratification was possible. Accurate estimation of the IVC state and the later thermodynamic evolution is important for any closed cycle analysis. The result from the IVC and TDC condition estimators indicate that it is possible to capture expected trends.
Lius, Andreas, Cronhjort, Andreas, Stenlaas, Ola
Effective Reduction of Emission Using a Natural Zeolite-Based Three-Way Catalyst05-15-03-00194/7/2022
Catalytic converters have been effectively controlling the harmful exhaust gases to meet stringent emission norms. This article presents a new three-way catalyst developed using natural zeolite for effective emission reduction. The step-by-step preparation of the material for the developed catalyst is followed by its characterization using an energy dispersive X-ray (EDX), X-ray diffraction (XRD), and scanning electron microscope (SEM). The testing performed on a synthetic gas test bench (SGTB) shows substantial carbon monoxide (CO), hydrocarbon (HC), and nitric oxide (NO) reduction. Results show a 100% conversion for NO above 280°C, 54.8% for CO at 315°C, and 52% for HC at 500°C. The developed natural zeolite-based catalyst stands out from among current catalysts and can be endorsed for three-way conversions than the synthetic zeolite catalyst.
Satpute, Sanjay T., Maske, Vidyasagar B., Kumbhar, Surajkumar G., Kumbhar, Sanjay R., Kurane, Rajanikant M.
Reduction of Ammonia Emission using Deceleration Cylinder Cutoff in a Gasoline Spark Ignition Engine2022-01-05373/29/2022
The newly proposed Euro 7 emission standards have added regulations limiting ammonia emissions for gasoline vehicles. This paper proposes a new emissions-control strategy to satisfy the regulated ammonia emission levels, using deceleration cylinder cut-off (DCCO) to reduce or eliminate conventional deceleration fuel cutoff (DFCO) and the associated lean-rich excursions in the three-way catalyst during oxygen saturation and desaturation. The improved air-fuel ratio management closer to stoichiometry lowers the ratio of CO to NOx and thus the ammonia (NH3) formation rate inside catalytic converter. Tests show more than 80% reduction of ammonia emission on the WLTC drive cycle without increasing other regulated emissions.
luo, Xi, Yang, Xiaojian, Wilcutts, Mark, Ortiz-Soto, Elliott
Investigations of Process and Component Parameters for the Number of Particles and Size Distribution of a Supercharged DI-SI Engine2022-01-05823/29/2022
Due to the short mixture formation times in the direct injection of modern gasoline engines, there is an increase in the emission of undesirable particle emissions. It is well known that particulate mass is not very high compared to diesel engines. However, the harmful small particles are a problem, which has led to the legislator limiting the number of particle emissions. As a result of previous studies with a portable emission measurement system (PEMS) of raw cleaned exhaust gas, the particle number (PN) of the sampling point after the catalyst was higher than before the catalyst at the same process parameters and engine operating points. Based on this reproducible phenomenon, several theories were proposed. The theories set up dealt on the one hand with the question of process control with regards to the formation of particles, but also fundamentally if conventional exhaust gas aftertreatment systems (three-way catalytic converters) are suitable for influencing the number of particles. To verify these theories and to investigate the influence of the catalyst on the PN and the particle size distribution (PD), several series of measurements were taken. In general, the investigations and measurements cover process and component related topics. Specifically, the authors combined several measurements of injection parameters, such as variation of rail injection pressure and start of injection (SoI) at steady state operating points. Further investigations were conducted with the equivalence ratio and its effects on PN and PD before and after the catalyst, respectively. Such investigations make sense, since normally the so-called forced excitation of the catalytic converter only relates to the conversion of the gaseous pollutants. For the time dependent PN measurement PN(t), the authors found a correlation between the AFR controller and PN. This newly found relationship enables the forced excitation of the catalyst to be optimized for the conversion of particle components. To date, the parameters AFR-setpoint, period duration and period length have been calibrated exclusively according to the criterion of the oxygen storage capacity and thus according to the conversion of the gaseous pollutants.
Dost, Tobias, Getzlaff, Joern, Schambach, Ricardo
Carbon Footprint Calculation of Catalytic Converter Production - an Industrial Case Study2022-32-00261/9/2022
The carbon footprint calculation of a catalytic converter coating process at Heraeus Precious Metals is presented in this publication. The emission hot spots are identified and discussed. Heraeus Precious Metals is a German world-wide leading company in the field of precious metal products and Tier-1 Supplier of emission catalytic converter coatings. In the first step of the carbon footprint calculation, all relevant raw materials and production process steps of the coating process are collected and modelled by use of a flowchart. In this case study the manufacturing of the metal honeycomb carrier is not included in the calculation. Transport emissions from the origin of the raw materials to the manufacturing plant of Heraeus Precious Metals in Germany are also considered in the carbon footprint calculation. Included activities for the production of the washcoat dispersion are the mixing of all components by use of an electric agitator and the grinding of the mixture by use of an electric mill. Further, multiple coating processes of the honeycomb carrier and the subsequent drying in a belt drier are considered. Finally, the catalytic converter is tempered in an electric oven. The calculation results are analyzed, and emission hotspots are identified. The calculated carbon footprint reveals several optimization potentials for carbon emission reduction in the catalytic converter production. It can be concluded that the main source of carbon dioxide emission are the raw material extraction emissions of the precious metals platinum and rhodium. Regarding the production processes, the thermal processes provide the highest potential for optimization.
Merschak, Simon, Hehenberger, Peter, Bonifer, Marcus
Impact of 3-way catalytic converters on particulate emission of MPFI motorcycle engines2022-32-00041/9/2022
Due to climatic movements and politics, there is no doubt that a stricter emission legislation will soon face the two-wheeler sector and their manufacturers with new challenges. Additional to the already limited pollutants, a limitation of particulate number will probably also be introduced, which means that there is an urgent need for action in exhaust gas after treatment and particulate reduction systems. For natural aspirated, port injected engines, as used in two-wheeler-technologies, conventional systems already established in passenger cars are not necessarily applicable. Moreover, the emission spectrum is fundamentally different from passenger car engines due to the better homogenization of they typically used MPFI engine types. Adapting conventional particulate filter technologies to the finer particles of MPFI engines would result in a disproportionately larger exhaust backpressure. For this reason, we are investigating the effects of 3-way catalytic converters on particulate number emissions from MPFI engines in the two-wheeler sector and possible modifications to increase filtration and particulate burn-off. The characteristic properties of the catalyst investigated in this context relate to cell density, honeycomb construction, foil technologies and coatings and their effect on the emission behaviour of particles of different size classes. Initial investigations showed that the 3-way catalyst has significant influence on particle emission due to its design and exothermic reactions. An adjustment of the already mentioned characteristics of the catalyst shows further reduction possibilities especially for ultrafine particles smaller than 10 nm. With increasing size and the accompanying bigger thermal inertia of the particles, the reduction potential decreases sharply within a few nanometres. For the reduction of this class of larger particles, however, it is inevitable to rely on well-known technologies in order to either prevent their formation in the internal combustion process or to store them in the aftertreatment system by means of suitable filters in order to fractionate and burn them.
Schurl, Sebastian, Schmidt, Dr. Stephan, Bonifer, Dr. Marcus
A Novel Idea for Replacement of Traditional Catalytic Converter with Multi-tubular Solid Oxide Fuel Cell13-03-01-000812/23/2021
Emission Control has always been a major concern in each and every field. An increase in emissions leads to climate change, global warming, and even various diseases. The transportation system is responsible for around 30% of emission production, of which 70% of the total atmospheric burden comes from automobiles. Recently developed emission-free electric vehicles have positively affected the levels of impurity in the environment, yet the remaining Internal Combustion Engine (ICE) vehicles on the road have been left with unchecked emissions. Traditional Catalytic Converters are widely used to reduce the emissions of vehicles. It works on the principle of converting hazardous gases emitted from the engine to less harmful carbon dioxide (CO2), nitrogen (N2), and water (H2O). It is integrated with the exhaust of the engine. High efficiency and better emission control catalytic converters are still major milestones to achieve for automotive industries. For this purpose, a new approach is proposed consisting of the integration of a two-phase multi-tubular Intermediate-Temperature Solid Oxide Fuel Cell (IT-SOFC)-based catalytic converter with an exhaust for amplified and better emission control. A multi-tubular IT-SOFC will use the burnt as well as unburnt emissions from the engine to create a potential that will generate electrical energy by oxidizing fuel. This generated electricity can be further utilized as per requirement. This system will positively impact nature by reducing, recycling, and converting harmful emissions into less harmful emissions.
Hole, Avadhoot
“EVO: New Metallic Substrate Development for Commercial Vehicle and Non-Road Applications”2021-26-02119/22/2021
Affordable, efficient and durable catalytic converters for the Commercial Vehicle and Non-Road industry in all countries are required to reduce vehicle emissions under real world driving conditions and fulfill future legal requirements. Specially for India traffic conditions and payload to engine size conditions new cost-effective solutions are needed to participate in a cleaner and healthier environment. Metallic substrates with structured foils like the Transversal StructureTM (TS) or the Longitudinal StructureTM (LS) have been proved to be capable of improving conversion behavior, even with smaller catalyst size. Now Vitesco Technologies is developed a new Substrate for Heavy duty applications that specifically maintains the geometric surface area at a very high level and improves further the mass transport of the pollutants, which potentially leads together to very high pollutant conversion rates. Together with active temperature management this solution will maintain a high conversion rate under all driving conditions. The paper will describe the new “EVO” metallic substrate and will cover the durability and performance aspects with experimental emission measurements under relevant testing cycle on engine bench. The results will be discussed and the benefits of the EVO metallic substrate for a Commercial Vehicle and Off-road application will be drawn.
Brueck, Rolf, Laddha, Paresh, Presti, Dr. Manuel, odenthal, David, Mueller-Haas, Klaus
Regulatory Norms and Effect on Transmission Component Validation2021-26-04609/22/2021
With the advent of BS VI regulations, automotive manufacturers are required to innovate the powertrains, fuel systems, exhaust and its after treatment systems to meet the regulatory requirements. The exhaust regulations can be met either by reducing the exhaust gases being generated by the engine (attacking the source) or by treating the exhaust gases in after treatment devices. The choice of the opted system varies with the manufacturer. The after-treatment devices such as catalytic converters are generally mounted in the engine compartment to take advantage of high temperature of exhaust gases to yield the reactions. Such an arrangement imposes a lot of thermal load on the peripheral components such as gearshift cables, bearings, oil seals, driveshafts etc. Thermal shields or thermal sleeve are used to address thermal issue and to protect transmission components. System level validation test requirement of transmission need to be re-visited considering change in environmental condition of operation. Also, component level test related to thermal sleeve and thermal shield need to be included in the component level validation plan. This paper discuss different validation requirement derived to validate the thermal sleeve and thermal shield from performance and durability point of view at system level and component level. Effect of parameters such as air gap, rotational speed (for component such as driveshaft), temperature of source, air draft, presence of dust and dirt in the operating environment etc for the derivation of test criteria are also discussed in detail. This paper also explains the test setup requirements for the thermal data acquisition during validation test. Proposed validation process help to get early feedback during the development and reduce the overall development time by avoiding requirement of complete validation of affected aggregates at vehicle level.
Tongaonkar, Yogesh Manohar, Patel, Hiral, Tendulkar, Vishveshvar, Bhosale, Vikas, halingale, Amol
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