Exhaust Emission Regulations Research Articles

Fundamental Study for Applying a Propane Gas Injection System in a Small-Ship Engine

As a response to stricter exhaust emission regulations, an increasing number of diesel-powered ships are switching to liquefied natural gas (LNG) fuel or installing post-processing devices to reduce exhaust gas. However, these methods are not feasible for small ships operating primarily along the coast. This is because the cost of the exhaust gas post-processing devices is high, while a large-volume fuel system is required in the case of LNG. Thus, this study used a propane gas fuel system based on a 5.0 L gasoline engine for easy application to existing small ships without major modifications. To optimize the control according to changes in the fuel system, a 1D simulation was performed on the engine to be developed, and ignition timing optimization was investigated. In addition, fuel consumption was compared with that of a gasoline-based engine. The propane engine achieved over 95% power in comparison to a gasoline-based engine. During cold-start tests, starting performance at −15 °C was ensured. The purpose of this study is to provide guidelines to assist the development of LPG or propane engines based on gasoline engines through these processes.

State of the Art on Vehicular Engine Exhaust Emissions Standards and Regulations: a Review

State of the Art on Vehicular Engine Exhaust Emissions Standards and Regulations: a Review

Research on The Ultra-Low Emission Technology in Internal Combustion Engine

Increasing the efficiency of internal combustion engines is a technologically proven and cost effective approach to dramatically improving the fuel economy of the nation’s fleet of vehicles in the near- to midterm, with the corresponding benefits of reducing our dependence on foreign oil and reducing carbon emissions. This review paper discusses on the research of ultra-low emission technology in internal combustion engine. Efficiency can be increased by improving combustion processes, minimizing engine losses such as friction, reducing the energy penalty of the emission control system and using recovered waste energy in propulsion. Compliance with exhaust emission regulations will be mandated and requires after-treatment technologies integrated with the engine combustion approaches. Fuels under consideration include hydrocarbon-based. Because of their relatively low cost, high performance, and ability to utilize renewable fuels, internal combustion engines, including those in hybrid vehicles, will continue to be critical to our transportation infrastructure for decades.

Low‐fuel‐permeation thermoplastic vulcanizates prepared from mutually miscible fluoroelastomer and poly(vinylidene fluoride–hexafluoropropylene)

AbstractAn oleophobic barrier material is imperative for automotive fuel hose applications to reduce permeation of air‐polluting hydrocarbons. With the increasingly strict exhaust emission regulations, the development of new fluoroelastomer (FKM) materials with enhanced fuel permeation resistance is highly desirable. Herein, we successfully developed a class of all‐fluorinated thermoplastic vulcanizates (TPVs) by dynamic vulcanization from FKM and poly(vinylidene fluoride–hexafluoropropylene) (P(VDF‐HFP)). The mechanical properties, recyclability and fuel resistance of the FKM/P(VDF‐HFP) TPVs were examined. The results show that the FKM/P(VDF‐HFP) blends present high mechanical performance with tensile strength up to 26.3 MPa and strain at break of more than 600% at a high rubber/plastic ratio of 7:3 by weight. Moreover, our FKM/P(VDF‐HFP) TPVs show excellent fuel resistance and recyclability. Such high mechanical properties, recyclability and fuel resistance are correlated with the good miscibility between FKM and P(VDF‐HFP), the strong FKM rubber network and the fine phase morphology of TPVs. This work provides a guidance for the preparation of new TPVs through selecting mutually miscible polymers without any compatibilizer, and demonstrates that these new TPVs can be a good alternative option to replace the traditional thermosetting fluororubbers in the automotive industry as barrier layers for fuel hoses. © 2023 Society of Industrial Chemistry.

Characterization of Particle Number Setups for Measuring Brake Particle Emissions and Comparison with Exhaust Setups

The stringency of vehicle exhaust emissions regulations resulted in a significant decrease in exhaust particulate matter (PM) emissions over the years. Non-exhaust particles (i.e., from brakes and tyres) account for almost half or more of road transport-induced ambient PM. Even with the internal combustion engine ban in 2035, electrified vehicles will still emit PM from brake and tyre wear. Consequently, non-exhaust PM emissions cannot decrease significantly without any regulatory measures. Because independent research carried out under different methods is not readily comparable, a Global Technical Regulation (GTR), which sets the procedures and boundaries of testing brake wear particle emissions, is currently under development. This overview describes the particle number (PN) measurement setup based on the well-known exhaust emissions PN methodology. We provide the technical requirements and the expected maximum losses. In addition, we estimate the effect of particle losses on the differences between different setups for typical size distributions observed during brake testing. Finally, we compare brake testing PN specifications to those of exhaust PN.

Stability analysis and development of gear shift patterns for an eight speed automatic transmission vehicle

The increasing stringency of exhaust emission regulations, as well as the rising index of carbon dioxide emissions from the road transport, has driven auto manufacturers and designers to develop solutions for even more efficient vehicles, with well-designed vehicle transmission and gear shift patterns among the alternative approaches used. The current article proposes a design method for developing an appropriate gear ratio set and gear shift patterns for an eight-speed automatic transmission. The BMW M4 Eight speed transmission model was developed using the MATLAB/Simulink platform, and the results were validated using experiment data. The effectiveness of the previously chosen gear ratio set and gear shift patterns was then assessed using a eight-speed transmission model based on the validated six speed transmission model. Based on a mathematical simulation approach, this article presents a novel microscopic model to illustrate the traffic phenomenon. The stability of the proposed model is investigated using the perturbation technique in order to analyze it and determine its stability conditions. The mathematical experimental tests were carried out, and the results reveal that the proposed model is valid. Patterns for sport mode, eco mode, and an accomplished by two modes were analyzed and the results.

Research on Application Characteristics of Zirconia-Based High-Temperature NOx Sensors

The zirconia solid electrolyte SOFC (solid oxide fuel cell) has the characteristics of oxygen ion conduction function, high-temperature resistance, thermoelectric coupling effect, etc. A NOx sensor based on zirconia solid electrolyte has common characteristics and problems with the SOFC in principle and application. The research objective of this paper is to solve the application problems of smart NOx sensors in diesel vehicles or gasoline vehicles. Improvements in the application performance of the NOx sensor can help the NOx emissions of gasoline vehicles or diesel vehicles better meet the requirements of emission regulations. The smart NOx sensor is a regulatory sensor required by vehicles for China’s Phase VI Vehicle Exhaust Emission Regulations or Euro Phase VI Vehicle Exhaust Emission Regulations. The smart NOx sensor is a key sensor device for improving fuel efficiency and reducing pollution. Moreover, its measurement performance includes dynamic immunity to interference, response speed, and measurement accuracy, which are key factors affecting vehicle emissions. This paper focuses on the impact of the physical structure, electrode characteristics, and control strategies of the sensor on its performance during the application. An excellent sensor structure, electrode structure, and control strategy are given based on application analysis and experimental testing. The results show that the application performance of this smart NOx sensor meets the requirements of exhaust aftertreatment systems.

Deep learning approach for super-knock event prediction of petrol engine with sample imbalance

Petrol engine becomes much smaller and has higher compression ratio due to the strict exhaust emission regulations and consumer demand for power performance. Meanwhile, the frequency of super-knock is increasing sharply at low speed of high load working region, which has great damage to engine components. Prediction of super-knock is therefore of great significance to optimize operation conditions and prolong service life. High-performance in-cylinder sensors can provide quality information for super-knock prediction, but at a price that production vehicles cannot afford. An approach that does not require additional engine sensors while having an acceptable accuracy rate is needed. Furthermore, the super-knock events are difficult to capture, making prediction task subjects to sample imbalance. In this research, a deep learning approach using only existing engine sensors was applied to address the challenge. Specifically, a two-stage model was designed: (i) Feature extraction, an LSTM based triplet network is built to extract the differential features between super-knock and normal combustion from the engine working cycles. (ii) Classification, to effectively use the extracted features and metric information from the previous stage, a modified KNN classifier is employed. The effectiveness of the proposed approach, i.e., TLSTM-KNN was evaluated and compared with other state-of-the-art methods on an actual engine-based dataset under different imbalance ratios (IR). The prediction precision and recall of super-knock event reach to 81.67% and 79.01% for the test dataset at IR=10. Even at IR=100, the precision and recall reach to 59.02% and 63.31%. The comparisons suggested that the proposed model provides better prediction performance and robustness capability compared to other traditional prediction models. Finally sensitivity analysis was used to explore the factors influencing super-knock.

Selective catalytic reduction: Adding an ammonia slip catalyst mitigates dosing errors

AbstractThis paper uses computational simulation to compare the performance of two catalytic systems designed for the removal of oxides of nitrogen from automotive engine exhaust using selective catalytic reduction (SCR). The first system is comprised of an SCR catalyst alone, whilst the second system adds an ammonia slip catalyst (ASC) to the end of an SCR catalyst. Both systems had the same total length. Comparisons of the NOx removal efficiency and the degree of ammonia slip are made using driving cycles and an optimized ammonia dosing strategy. Comparisons are also made for the case where a constant error in the ammonia dosing occurs. The addition of the ASC reduces ammonia slip during over‐dosing scenarios and gives a greater NOx conversion during under‐dosing cases. This work concludes that the ASC is a positive addition to the SCR in meeting the exhaust emission regulations. Although it does not necessarily allow for a higher NOx conversion, its ability to cope with under‐ and over‐dosing situations can be beneficial in catalyst aging and unpredictable driving conditions.

Evolution of gear shift patterns for six speed automatic transmission vehicle

The increasing level of stringent exhaust emission regulations and the rising index of carbon dioxide emissions from the road transport sector have pushed vehicle manufacturers and designers to develop solutions for more efficient vehicles, with well designed vehicle transmission and gear shift patterns among the alternative approaches employed. For a six speed automatic transmission, the current article proposes a design method for developing a suitable gear ratio set and gear shift patterns. The MATLAB/Simulink platform was used to create the Maruti Suzuki 2020 four speed transmission model and the results were verified using experiment data. The effectiveness of the new selected gear ratio set and gear shift patterns was then evaluated using a six speed transmission model based on the validated four speed transmission model. To investigate fuel consumption and acceleration performance, all models were simulated based on motor vehicle emissions groups. Sport mode, eco mode, and combined both mode patterns were developed and analyzed. Based on the eco mode pattern, the six speed transmission model has a 2.74% lower fuel consumption rate than the four speed transmission model, indicating that the proposed design method is feasible and effective.

Development of a model predictive controller for an active torsional vibration damper to suppress torsional vibrations in vehicle powertrains

The pressure of exhaust emission regulations on automotive manufacturers to reduce environmental pollution and fuel consumption of internal combustion engines (ICEs) have stimulated the works on the downsizing, downspeeding, and turbo supercharging concepts which result in boosted engine torsional vibrations. Despite significant momentum in the implementation of those concepts in modern ICEs in recent decades, similar progress has not taken place in parallel at torsional vibration isolation systems. To this end, this article centers on the development and implementation of a model predictive controller (MPC) on a novel active torsional vibration damper (ATVD) in which inertia, stiffness rate, and damping rate parameters can be varied to minimize torsional vibration transmission to the vehicle powertrain. Dynamic response of the ATVD is examined using an MPC inside a closed-loop control architecture with predicted variables. The MPC structure, state-space plant model, and physical constraint definitions are composed to be utilized in prediction models at various engine operating points. The MPC performance is evaluated in a co-simulation environment using Simcenter Amesim, NX Motion, and Matlab Simulink software, and are compared with that of the fuzzy logic controller (FLC). The simulation results clearly indicate that the MPC applied to the ATVD system has certain advantages over the FLC and is able to provide satisfactory isolation of the powertrain from engine-borne torsional vibrations while satisfying the physical constraints.

Deep-learning based in-cylinder pressure modeling and resolution of ion current signals

Engine calibration becomes much more costly due to strict exhaust emission regulations and individual consumer needs. Measuring the in-cylinder pressure could be a promising alternative for various sensors, thus reducing the calibration cost because the measurement provides diverse, low-delay, and precise information inside the cylinders. However, a piezoelectric pressure sensor for this measurement is too expensive, which prevents its use in production vehicles. The less-expensive, more reliable, and responsive ion current measurement provides signals that highly correlate with the in-cylinder combustion process and pressure. Many proposed methods correlate the ion current and pressure through chemical-kinetic models or manually tuned machine-learning models. A few methods can automatically estimate the pressure change or predict the peak pressure with the ion current, which provides valuable information for advance control and engine monitoring. In this paper, an autoencoder deep-learning model is developed that is unprecedentedly well fit for these two tasks. It automatically encodes ion current signals into a semantic representation with a convolutional neural network. With this, the model can either predict the peak pressure or estimate the pressure change through the gated-recurrent-unit decoder of the model. The evaluation of the model predictions and estimations is performed on an actual engine-based dataset, where the model demonstrates state-of-the-art performance on both tasks, and the mean relative error is 7.84% and 19.68%, respectively. Additionally, an orthogonal analysis method is applied to study the resolution of the ion current signals, making it possible to categories these signals by converting them into semantic representations.

Long-term trend of regional passenger road transport demand and emission estimation under exhaust emission regulation scenario in Thailand

Economic development, transport demand, and air pollution are interrelated. The heterogeneity of economic development among regions and the freezing of exhaust emission regulations for approximately a decade in Thailand were the motivations for this study. Herein we provide a comprehensive analysis of vehicle exhaust emission projections for up to 2050 with specific regional breakdown for passenger transport mode and volume; we also provide region-wise and mode-wise outcomes to help understand the effects of enhancing exhaust emissions regulation for future air pollutant emissions. The results from this study reveal the limitations of current regulations and establish the need to enhance regulations within this decade to cope with air pollution for the long-term growth of regional economic development.

NOx Oxidation and Storage Properties of a Ruddlesden-Popper-Type Sr3Fe2O7-δ-Layered Perovskite Catalyst.

The development of NOx-trapping catalysts for automobiles is highly desired to meet the current strict exhaust emission regulations. This study demonstrates that NOx oxidation and storage reactions proceed over Pt-free Sr3Fe2O7-δ with a Ruddlesden-Popper-type layered perovskite structure. Two types of Sr-Fe perovskite with oxygen storage capacity, namely, SrFeO3-δ and Sr3Fe2O7-δ, are studied as NOx-trapping catalysts. Sr3Fe2O7-δ shows higher NOx storage capacity than SrFeO3-δ; its activity is comparable to that of Pt/Ba/Al2O3 calcined at 1273 K. NOx temperature-programmed desorption and diffuse reflectance infrared Fourier transform experiments confirm the superior NOx-trapping ability of Sr3Fe2O7-δ over SrFeO3-δ. In addition, NO temperature-programmed reactions and O2 temperature-programmed desorption experiments reveal that these catalysts operate through a novel NO oxidation mechanism involving the consumption of their lattice oxygens and topotactic structural changes at a temperature of around 350-400 K. The reduction performance of trapped NOx on Pd-modified Sr-Fe perovskites is investigated by lean-rich cycle experiments using H2 as the reductant. Pd/Sr3Fe2O7-δ shows significantly high NOx removal efficiency over the entirety of each lean-rich period. Modifying Sr3Fe2O7-δ with Pd is also effective for NOx storage in the presence of H2O and CO2 and the regeneration of the catalyst following SOx sorption. Sr3Fe2O7-δ, with both NOx adsorption and NO oxidation capabilities, acts as a Pt-free NOx-trapping catalyst, exhibiting both high NOx storage capacity and high thermal tolerance.

Development of a Friction Welded Joint for Future Industrial Application

Ship transport continues to be the most economical intercontinental means of transportation, which is becoming more and more under observation due to increasing international environmental protection regulations. In order to protect the marine biotope, the government is introducing stricter exhaust emission regulations, which mean the further development of low-emission large engines and thus make the development of new combustion chamber components indispensable. This paper presents FE simulations of a friction welding process for two metallic materials, which are being developed as part of a BMWi joint project for the production of innovative combustion chamber components. In addition, the first results of the simulations and their comparison with real tests are presented.

Exhaust emission regulation and exhaust reduction technology for automobiles

Exhaust emission regulation and exhaust reduction technology for automobiles

Performance Degradation and Poison Build-Up of an Oxidation Catalyst in Two-Stroke Natural Gas Engine Exhaust

Due to current and future exhaust emissions regulations, oxidation catalysts are increasingly being added to the exhaust streams of large-bore, two-stroke, natural gas engines. Such catalysts have a limited operational lifetime, primarily due to chemical (i.e., catalyst poisoning) and mechanical fouling resulting from the carry-over of lubrication oil from the cylinders. It is critical for users and catalyst developers to understand the nature and rate of catalyst deactivation under these circumstances. This study examines the degradation of an exhaust oxidation catalyst on a large-bore, two-stroke, lean-burn, natural gas field engine over the course of 2 years. Specifically, this work examines the process by which the catalyst was aged and tested and presents a timeline of catalyst degradation under commercially relevant circumstances. The catalyst was aged in the field for 2-month intervals in the exhaust slipstream of a GMVH-12 engine and intermittently brought back to Colorado State University for both engine testing and catalyst surface analysis. Engine testing consisted of measuring catalyst reduction efficiency as a function of temperature as well as the determination of the light-off temperature for several exhaust components. The catalyst surface was analyzed via scanning electron microscope (SEM)/energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) techniques to examine the location and rate of poison deposition. After 2 years online, the catalyst light-off temperature had increased ∼55 °F (31 °C) and ∼34 wt % poisons (S, P, Zn) were built up on the catalyst surface, both of which represent significant catalyst deactivation.

2009 年排出ガス規制および2015 年重量車燃費基準に適合させた大型ディーゼル エンジンとパワートレインの開発

2009 年排出ガス規制および2015 年重量車燃費基準に適合させた大型ディーゼル エンジンとパワートレインの開発

Storage of Nitrous Oxide (NOx) in Diesel Engine Exhaust Gas using Alumina-Based Catalysts: Preparation, Characterization, and Testing

This work investigated the nitrous oxide (NOx) storage process using alumina-based catalysts (K2 O/Al2 O3 , CaO/Al2 O3, and BaO/Al2 O3 ). The feed was a synthetic exhaust gas containing 1,000 ppm of nitrogen monoxide (NO), 1,000 ppm i-C4 H10 , and an 8% O2 and N2 balance. The catalyst was carried out at temperatures between 250–450°C and a contact time of 20 minutes. It was found that NOx was effectively adsorbed in the presence of oxygen. The NOx storage capacity of K2 O/Al2 O3 was higher than that of BaO/Al2 O3. The NOx storage capacity for K2 O/Al2 O3 decreased with increasing temperature and achieved a maximum at 250°C. Potassium loading higher than 15% in the catalyst negatively affected the morphological properties. The combination of Ba and K loading in the catalyst led to an improvement in the catalytic activity compared to its single metal catalysts. As a conclusion, mixed metal oxide was a potential catalyst for de-NOx process in meeting the stringent diesel engine exhaust emissions regulations. The catalysts were characterized by a number of techniques and measurements, such as X-ray diffraction (XRD), electron affinity (EA), a scanning electron microscope (SEM), Brunner-Emmett-Teller (BET) to measure surface area, and pore volume and pore size distribution assessments.

Advanced Catalytic Converter in Gasoline Enginer Emission Control: A Review

Exhaust emission from automobile source has become a major contributor to the air pollution and environmental problem. Catalytic converter is found to be one of the most effective tools to reduce the overwhelming exhaust pollutants in our environment. The development of sustainable catalytic converter still remains a critical issue due to the stringent exhaust emission regulations. Another issue such as price and availability of the precious metal were also forced the automotive industry to investigate the alternatives for producing a better replacement for the material used in catalytic converter. This paper aims at reviewing the present development and improvement on the catalytic converter used on the reduction of exhaust emission in order to meet the regulations and market demand. The use of new catalyst such as to replace the noble metal material of Platinum (Pt), Palladium (Pd) and Rhodium (Rh) has been reviewed. Material such as zeolite, nickel oxide and metal oxide has been found to effectively reduce the emission than the commercial converter. The preparation method of the catalyst has also evolved through the years as it is to ensure a good characteristic of a good monolith catalyst. Ultrasonic treatment with combination of electroplating technique, citrate method and Plasma Electrolytic Oxidation (PEO) has been found as the latest novel preparation method on producing an effective catalyst in reducing the exhaust emission.