Browse Topic: Catalytic converters

Items (994)
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
Vashisht, Shruti
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
Jagtap, PranjalSyed, KaleemuddinChaudhari, SandipKhairnar, GirishBhoite, VikramReddy, Kameswar
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
MUTHA, MAYURESHTalawadekar, PradnyaKale, Upendra
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
Rahman, MontajirNevius, TimIsrael, JoshuaHara, KenjiNagura, Naoki
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
Korkmaz, MetinJuressen, Sven EricRößmann, DominikKapus, Paul E.Pino, Sandro
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
Vaidyanathan, BalajiArunkumar, PraveenkumarShunmugasundaram, PalaniMurugesan, ManickamJayajothijohnson, Vedhanayagam
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
Wu, Ji-XinSu, Chu-QiWang, Yi-PingYuan, Xiao-HongLiu, Xun
Fossil fuels such as natural gas used in engines still play an important role worldwide which however is also exacerbating climate change as a result of carbon dioxide emissions. Although natural gas engines show an overall low pollutant emissions level, methane slip due to incomplete combustion occurs, causing methane emissions with a more than 20 times higher global warming potential than CO2. Additionally, further tightening of emissions legislation is to be expected bringing methane emissions even more into focus making exhaust gas aftertreatment issues remain relevant. For lean gas applications, (Pd)-based catalysts turned out to convert CH4 most efficiently usually being supported by metal oxides such as aluminium oxide (Al2O3). Water (H2O) contained in the exhaust gas causes strong inhibition on Pd catalysts. In real exhaust gases, not only water vapour but also pollutants and sulphur-containing compounds such as hydrogen sulphide (H2S) or sulphur oxides (SOx) are poisoning the
Tomin, SebastianWagner, UweKoch, Thomas
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.
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
Lott, PatrickSchäfer, KathrinDeutschmann, OlafWerner, ManuelWeinmann, PhilippZimmermann, LisaToebben, Heike
Design, testing, and implementation of new aftertreatment devices under various engine operating conditions is necessary to meet increasingly stringent regulatory mandates. One common aftertreatment device, the catalytic converter, is typically developed at a reduced scale and tested using predefined fluid compositions sourced from bottle gases and can undergo both species and temperature cycling in addition to steady-state testing. However, these bench-top conditions may differ from real-world operation in terms of flow-rates, species composition, and temperatures experienced. Transitioning from small-scale bench-top testing to full-scale engine applications requires larger monoliths that therefore have a significant amount of catalyst slurry to be washcoated, which increases cost and fabrication time. Being able to experience realistic emission streams under scaled flowrates would allow for a physically smaller catalyst testing at matched space velocities resulting in faster, more
Loprete, JasonRistow Hadlich, RodrigoSirna, AmandaAssanis, DimitrisMon, TalaKyriakidou, Eleni
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
Kannan, RajeshParamadhayalan, ThiyagarajanMital, RahulGustafson, ErikEdwards, David
Spark ignition engines utilize catalytic converters to reform harmful exhaust gas emissions such as carbon monoxide, unburned hydrocarbons, and oxides of nitrogen into less harmful products. Aftertreatment devices require the use of expensive catalytic metals such as platinum, palladium, and rhodium. Meanwhile, tightening automotive emissions regulations globally necessitate the development of high-performance exhaust gas catalysts. So, automotive manufactures must balance maximizing catalyst performance while minimizing production costs. There are thousands of different recipes for catalytic converters, with each having a different effect on the various catalytic chemical reactions which impact the resultant tailpipe gas composition. In the development of catalytic converters, simulation models are often used to reduce the need for physical parts and testing, thus saving significant time and money. However, calibration of these models can be challenging and requires significant time
Wilson, John ParleyDelVescovo, Dan
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
Gupta, BipinLi, JiangongSingaravel, Vinothkumar
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
Garg, RahulMukherjee, NaliniViswanath, ChithraChoudhary, VasuNewalkar, BharatNene, DevendraKusumba, Manoj
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
Bhimavarapu, AdityaSingh, Sunil KumarKataria, RohitRose, DominikBoger, Thorsten
The ever-tightening regulation norms across the world emphasize the magnitude of the air pollution problem. The decision to leapfrog from BS4 to BS6 – with further reduction in emission limits -showed India’s commitment to clean up its atmosphere. The overall cycle emissions were reduced significantly to meet BS6 targets [1]. However, the introduction of RDE norms in BS6.2 [1] demanded further reduction in emissions under real time operating conditions – start-stop, hard acceleration, idling, cold start – which was possible only through strategies that demanded a cost effective yet robust solutions. The first few seconds of the engine operation after start contribute significantly to the cycle gaseous emissions. This is because the thermal inertia of the catalytic converter restricts the rate at which temperature of the catalyst increases and achieves the desired “light-off” temperature. The challenge becomes more prominent in the turbocharged engines (where some part of exhaust heat
Kale, Vishal MarutiM, RavisankarHosur, ViswanathaSridhar, SBhimavarapu, AdityaLende, Nilesh AshokRose, DominikTao, Tinghong
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
Baviskar, AjayKhera, PankajTelgote, AshishDhuria, HimanshuSharma, Amit
Catalytic converters, which are commonly used for after-treatment in SI engines, exhibit poor performance at lower temperatures. This is one of the main reasons that tailpipe emissions drastically increase during cold-start periods. Thermal inertia of turbocharger casing prolongs the catalyst warm-up time. Exhaust enthalpy management becomes crucial for a turbocharged direct injection spark ignition (DISI) engine during cold-start periods to quickly heat the catalyst and minimize cold-start emissions. Thermal barrier coatings (TBCs), because of their low thermal inertia, reach higher surface temperatures faster than metal walls, thereby blocking heat transfer and saving enthalpy for the catalyst. The TBCs applied on surfaces that exchange heat with exhaust gases can increase the enthalpy available for the catalyst warm-up. A system-level transient heat transfer study using experimental or high-fidelity simulation techniques to evaluate the TBC application on various surfaces would be
Ravikumar, AvinashBhatt, AnkurGainey, BrianLawler, Benjamin
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
Dudley, Joshua PaulLaurell, MatsThuve, ChristofferKlövmark, Henrik
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
El Yacoubi, IsmailSamuel, Stephen
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
Agarwal, AvinashYadav, OmkarValera, Hardikk
For a quick reach to the operating temperatures, the three way catalytic converter is recently located closer to the engine and subjected to higher temperatures than before. At the same time, the three way catalytic converter has upper thermal limits. Therefore, the operating temperatures have to be estimated accurately in the early period of product development. In this research, the four analysis methods are linked with the one-dimensional engine cycle simulation to achieve the goals. Firstly, for the estimation of gas temperatures at the exhaust port of the engine, the combustion analysis using the 3D-CFD was conducted to accurately simulate the way the heat was generated. Then, for the estimation of heat dissipation from the exhaust system to the atmosphere, the heat conduction analysis coupled with the air flow analysis around the vehicle body using the 3D-CFD was conducted. To take into considerations the heterogeneity of reactions in the three way catalytic converter, the gas
Shigeno, GENKIFujita, Shinjiyogo, toyoyuki
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
Stoll, TobiasKulzer, Andre CasalBerner, Hans-Juergen
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
Leon de Syniawa, LarisaSiddareddy, Reddy BabuPrehn, SaschaGuenther, VivienFranken, TimBuchholz, BertMauß, Fabian
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
Stiborek, Joshua W.Tancin, Ryan J.Kempema, Nathan J.Szente, Joseph J.Loos, Michael J.Goldenstein, Christopher S.
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, HeikeWeinmann, Philipp
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
Mandloi, DeepakSahu, PrachiBagade, Monika JayprakashDas, Himadri
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
Zhu, ShengrongHollowell, JeffreyHa, Kyoung-PyoFantin, NicholasShirley, Mark
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
Petrini Fogaça, RômuloUrbani Amadei, GabrielL. Warkins, JasonA. Craig, Angus
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
Lius, AndreasCronhjort, AndreasStenlaas, Ola
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
Kraus, ChristophFitz, PatrickFellner, FelixHärtl, MartinJaensch, Malte
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
Lius, AndreasCronhjort, AndreasStenlaas, Ola
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.
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, XiYang, XiaojianWilcutts, MarkOrtiz-Soto, Elliott
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
Dost, TobiasGetzlaff, JoernSchambach, Ricardo
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
Schurl, SebastianSchmidt, Dr. StephanBonifer, Dr. Marcus
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
Merschak, SimonHehenberger, PeterBonifer, Marcus
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
Hole, Avadhoot
Kinetic modelling of exhaust aftertreatment systems is a topic of extensive research in the automobile sector. This study represents the modelling of catalytic reactions on the surface of platinum dispersed diesel oxidation catalysts. In addition to oxidation reactions in the catalytic converter, a model for hydrocarbon adsorption/desorption on zeolite was adopted and validated with experimental results. The model was further used to simulate the experimental results at two different Pt loadings on the catalyst surface. The simulated results were observed to fit reasonably well with the experimental results at each Pt loading on the catalyst. The adsorption/desorption behaviour on the catalyst surface was found to be affected by Pt loading. The simulation results have shown that Pt atoms might have occupied the active site of zeolite which resulted in the reduction of adsorption/desorption rates. Less Pt loading has caused more storage sites on the zeolite surface and hence, higher
Gupta, RajatRajan, BoscoMuthusamy, VishnuvarthanKumar, ArvindGaur, KanishkaBartley, GordonTrigunayat, Alok
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
Tongaonkar, Yogesh ManoharPatel, HiralTendulkar, VishveshvarBhosale, Vikashalingale, Amol
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
Brueck, RolfLaddha, PareshPresti, Dr. Manuelodenthal, DavidMueller-Haas, Klaus
Gasoline engine control strategies ensure a combustion control around stoichiometry. That is because the three-way catalytic converter allows CO and HC oxidation under lean operating conditions while ensuring NOx reduction for rich mixtures. In case of engine malfunction, the controller must adapt to compensate for potential torque loss and other critical attributes, potentially leading to significant deviation of the fuel-air mixture richness from stoichiometry and higher emission levels. Therefore, during development of the engine fault diagnostics, the impact on the pollutant emissions must be considered. In this paper, a model-based development process is proposed. It is based on system simulation modelling techniques, where a complete exhaust line is represented in order to predict tail-pipe emissions under stoichiometric, lean and rich conditions, for engine control design purposes. Two different modelling approaches are applied and evaluated in this paper. First, a physics-based
LOUSSAIEF, SanaAkhmetov, YerlanGROISIL, MelanieTakahashi, DaisukeKuhara, MasakiIsobe, YoshikiMas, Peter
The present work investigates a means of controlling engine hydrocarbon startup and shutdown emissions in a Wankel engine which uses a novel rotor cooling method. Mechanically the engine employs a self-pressurizing air-cooled rotor system (SPARCS) configured to provide improved cooling versus a simple air-cooled rotor arrangement. The novelty of the SPARCS system is that it uses the fact that blowby past the sealing grid is inevitable in a Wankel engine as a means of increasing the density of the medium used for cooling the rotor. Unfortunately, the design also means that when the engine is shutdown, due to the overpressure within the engine core and the fact that fuel vapour and lubricating oil are to be found within it, unburned hydrocarbons can leak into the combustion chambers, and thence to the atmosphere via either or both of the intake and exhaust ports. As well as shutdown it also affects the startup process, where higher hydrocarbon emissions are caused due to the forced
Turner, JamesIslam, RezaVorraro, GiovanniTurner, MatthewAkehurst, SamBailey, NathanAddy, Shaun
The three-way catalytic converter (TWC) is a vital component of the S.I. (Spark Ignition) engine to meet the current emission norms. TWC can perform the three conversion processes simultaneously. Hence, health diagnosis and performance monitoring of TWC is a major requirement of the power-train control system. In TWC modeling, the chemical species CO, THC, NOx, O2, and CO2 are the major components of the redox reaction over the wash-coat surface which impacts the overall conversion efficiency of the gases. This research work examines a generalized chemical model for a fresh catalytic converter validated for significant engine operating points in an urban drive cycle. The gas concentration measurements across the catalyst are harvested from an engine dynamo-meter test-bed. This work attempts to find the best method to optimize the chemical kinetic parameter of the Arrhenius equation parameters. An optimization framework is designed and has been tried on two different optimization
Mandloi, Deepakdhinagar PhD, SamrajDas, Himadri
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