Browse Topic: Nitrogen oxides

Items (4,915)

The Impact of GCI Engines on Long-haul Trucks in the US and China

2025-01-8396

04/01/2025

This study evaluates the impacts of the gasoline compression ignition (GCI) engine on heavy duty long-haul trucks in both the Chinese and US markets. The study examines various aspects such as vehicle performance requirements, fuel consumption, emissions, and ownerships costs, and how they influence the implementation and impact of new technologies in these markets. By considering a wide variety of drive cycles, including standard regulatory cycles and real-world cycles, the study aims to identify the impact of varying degrees of powertrain electrification using diesel and GCI engines on fuel consumption and emissions. Additionally, this paper explores the viability of powertrain electrification in long-haul trucks by analyzing factors such as levelized cost of driving (LCOD), manufacturing costs, and energy costs. These considerations play a crucial role in determining the economic feasibility and attractiveness of electrification technologies in various driving scenarios and market

Nieto Prada, Daniela, Vijayagopal, Ram, Yan, Ziming, Sari, Rafael, He, Xin

Achieving Ultra-Low NO _x and Meeting Full Useful Life Requirement for CARB 2027 NO _x and GHG 2027 Phase 2 CO ₂ Regulation w/Opposed Piston 2-Stroke Engine and a Conventional ATS

2025-01-8391

04/01/2025

Internal combustion engines are expected to continue to play an important on-going role in the future of transportation, particularly in long haul transit and off-road applications. Substantially reducing criteria emissions of heavy-duty (HD) commercial vehicle engines while also reducing fuel consumption is the quickest way to achieve more sustainable transportation. The opposed-piston (OP) engine developed by Achates Power has demonstrated the ability to meet the most stringent ultralow NOx emissions requirements using only a conventional, underfloor aftertreatment system, offering reduced cost, complexity and compliance risk compared to other diesel engines. This paper is focused on the measurement results of Achates Power heavy-duty engine achieving CARB proposed ultralow NOx emission for 2027 and 2031+ full useful life requirements while also meeting the EPA Greenhouse Gas (GHG) Phase 2 limits with a conventional aftertreatment system (ATS), which was aged to 435k, 600k and 800k

Kale, Vaibhav, Bako, Zoltan

Combustion and Emission Performance from the Use of Acid-Catalysed Butanol Alcoholysis Derived Advanced Biofuel Blends in a Compression Ignition Engine

2025-01-8445

04/01/2025

Low-carbon alternatives to diesel are needed to reduce the carbon intensity of the transport, agriculture, and off-grid power generation sectors, where compression ignition (CI) engines are commonly used. Acid-catalysed alcoholysis produces a potentially tailorable low-carbon advanced biofuel blend comprised of mixtures of an alkyl levulinate, a dialkyl ether, and the starting alcohol. In this study, model mixtures based on products expected from the use of n-butanol (butyl-based blends) as a starting alcohol, were blended with diesel and tested in a Yanmar L100V single-cylinder CI engine. Blends were formulated to meet the flash point, density, and kinematic viscosity limits of fuel standards for diesel, the 2022 version of BS 2869 (off-road). No changes to the engine set-up were made, hence testing the biofuel blends for their potential as “drop-in” fuels. Changes in engine performance and emissions were determined for a range of diesel/biofuel blends and compared to a pure diesel

Wiseman, Scott, Li, Hu, Tomlin, Alison S.

Comprehensive Prediction of Deposit Formation in SCR Systems Using Integrated 1D Heat Transfer Model with Empirical Data from 3D CFD Simulations

2025-01-8491

04/01/2025

Urea-based selective catalytic reduction (SCR) systems are widely used to meet stringent NOx emission standards in industrial diesel engines. However, suboptimal design of the urea-water solution (UWS) mixing pipes in SCR systems can lead to the formation of urea-derived solid deposits, which may adversely affect the system performance and reliability. Although recent advancements in deposit simulation technology using three-dimensional Computational Fluid Dynamics (3D CFD) have significantly improved the performance and compactness of mixing pipes, assessing deposit formation across all operating and environmental conditions remains challenging due to high simulation costs. This study introduces a novel computational method for predicting the formation and temperature of permanent liquid films from UWS injection which are closely related to deposit formation, along with new deposit evaluation criteria based on them. This proposed method integrates a one-dimensional heat transfer model

Sugimoto, Kazuma, Kawabe, Ken

Potential for Reduction in NRMM Real-World Emissions

2025-01-8489

04/01/2025

The pollutant emission regulation for Non-Road Mobile Machinery (NRMM) is currently under consideration, both in the European Union (EU) and the United States (US). In Europe a Stage V review is expected within 2025 and in the US, the California Air Resource Board (CARB) has released their Tier 5 proposal in late 2024. It is expected that there will be further focus on covering a wide variety of operation conditions in actual use cases, including continuous low load scenarios. In addition, CO2-neutral fuels are being investigated to reduce the carbon footprint of NRMM Internal Combustion Engines (ICE), which remains an important powertrain for the sector. The objective of the work presented is to assess the potential for emissions reductions in the future, both NOx and CO2. A simulation study is conducted, modelling a 9l class engine with 8-10 g/kWh engine-out NOx emission level. Three different emission control systems are investigated: an enhanced stage V system with single SCR, a

Demuynck, Joachim, Bosteels, Dirk, Michelitsch, Philipp, Noll, Hannes

Model-Based Evaluation of Hybrid Powertrains for a Light Duty Pickup Truck Application

2025-01-8532

04/01/2025

In recent years, the stronger push for reducing GHG and NOx emissions has challenged vehicle manufacturers globally. In USA, Multi-Pollutant Emissions Standards for Model Years 2027 and Later Light Duty and Medium-Duty Vehicles released by EPA in April 2023 aims to reduce the CO2 emissions by 56% and 44%, respectively, for light and medium duty vehicles by 2032 from 2026 levels. It also includes the NMOG+ NOx standards, which require a 60 – 76% reduction by 2032 from 2026 levels for light to medium-duty vehicles. Europe also aims to reduce CO2 emissions by 55% by 2030 from 1990 levels and 100% by 2035. To achieve such low levels of CO2 emissions, especially in the near-term scenario of limited EV sales, hybridization of conventional powertrains has found renewed interest. While hybrid powertrains add complexity, if optimized well for the application, they can offer best tradeoff between upfront cost, range, payload, performance, emissions and off-ambient operation. This study

Fnu, Dhanraj, Correia Garcia, Bruno, Paul, Sumit, Joshi, Satyum, Franke, Michael

High-Performance and Stable Three-Way Catalyst Achieved Via Ultrasonic Treatment for Gasoline Vehicle Emission Control

2025-01-8480

04/01/2025

Three-way catalysts (TWCs) containing significant amounts of precious metals are commonly employed to purify exhaust emissions (CO, NOx, and THC) from gasoline-powered vehicles. A critical factor contributing to TWC degradation is the sintering of these precious metals. Maintaining the appropriate particle size and distribution of the metals is essential for optimal catalyst performance. In this study, palladium (Pd) nanoparticles with a uniform size were synthesized using ethylene glycol as a reductant under ultrasonic conditions, yielding particles in the range of 3 nm to 5 nm. These Pd nanoparticles were subsequently used to prepare three-way catalysts on cordierite substrates supplied by Corning (China) Inc. Chemisorption analysis revealed that the Pd active component in the catalysts prepared via the ultrasonic method exhibited higher dispersion than the state-of-the-art commercial catalysts. The aged catalysts were obtained after 150 hours of aging following the General Motors

Hao, Shijie, Lv, Yanan, Wang, Weidong, Rao, Chao, Wei, Wei, Mao, Bingbin, Chen, Tao, Zhao, Huawang

Effects of Injection Timing and Pressure on Combustion Performance and Emissions in Hydrogen Direct Injection Engine

2025-01-8421

04/01/2025

As the demand for cleaner and more efficient propulsion systems increases, hydrogen internal combustion engines have emerged as a promising solution due to their high thermal efficiency and zero-carbon emissions potential. Achieving ultra-lean combustion conditions (lambda > 2.8) in hydrogen engines significantly improves thermal efficiency while maintaining combustion stability and reducing knock intensity. However, hydrogen injection timing and pressure are crucial factors influencing the combustion and emission characteristics of hydrogen engines. This study investigates the effects of hydrogen injection timing and pressure on the combustion performance and emission characteristics of a direct injection hydrogen engine under different load conditions. Experimental tests were conducted on a multi-cylinder engine equipped with a hydrogen direct injection system, focusing on part-load operation to explore the interplay between injection parameters and engine performance. Results show

Du, Jiakun, Wu, Guangquan, Chen, Hong, Sun, Fanjia, Xie, Fangxi, Li, Yuhuai, Sun, Yao, Qi, Hongzhong, Li, Yong

Nitrogen Oxides Reduction Potential Via Water Direct Injection in a Single-Cylinder Hydrogen-Fueled Direct Injection Spark Ignition Engine

2025-01-8427

04/01/2025

In hydrogen-fueled internal combustion engine (H2ICE), there are some ways to reduce nitrogen oxides (NOx) emissions. Using the wide flammability range of hydrogen, such as conducting lean combustion to reduce nitrogen oxides and employing exhaust gas recirculation (EGR), have been adopted. However, challenges exist in terms of load expansion, and due to the absence of high heat capacity of carbon dioxides in the exhaust, EGR also struggles to exhibit significant effects. In such a scenario, there is growing interest in injecting water into the H2ICE as an alternative to augment the EGR effect. In this study, the spark ignition (SI) single-cylinder engine equipped with two direct injectors was used to evaluate the hydrogen and the water dual direct injection combustion system. This system involved the direct injection of hydrogen using a wall-guided gasoline direct injector and the direct injection of water into the combustion chamber using a diesel injector. This approach utilizes the

Kim, Kiyeon, Lee, Seungil, Kim, Seungjae, Lee, Seunghyun, Min, Kyoungdoug, Oh, Sechul, Son, Jongyoon, Lee, Jeongwoo

Numerical Investigation of Fuel Injection Strategies for Ammonia-Diesel Dual-Fuel Engine

2025-01-8368

04/01/2025

This study numerically investigates ammonia-diesel dual fuel combustion in a heavy-duty engine. Detailed and reduced reaction mechanisms are validated against experimental data to develop injection timing maps aimed at maximizing indicated thermal efficiency (ITE) while mitigating environmental impacts using stochastic reactor model (SRM). The equivalence ratio, ammonia energy share (AES), injection timing, and engine load are varied to optimize combustion efficiency and minimize emissions. The results demonstrate that advancing injection timing reduces ITE due to heightened in-cylinder temperatures, resulting in increased heat losses through walls and exhaust gases. Maximum chemical efficiency is observed at an equivalence ratio near 0.9 but decreases thereafter, influenced by ammonia’s narrow flammability range. Emission analysis highlights significant reductions in Global Warming Potential (GWP) and Eutrophication Potential (EP) with higher AES, driven by decreased CO2 and nitrogen

Karenawar, Shivraj Anand, Yadav, Neeraj Kumar, Maurya, Rakesh Kumar

The Numerical Study of Methane Flame Characteristics in the Ammonia/Air Environment at Sub-Atmospheric Pressure

2025-01-8450

04/01/2025

The low emission of carbon and minimum level of soot formation in combustion engines and turbines strategy is adopted by many countries to counteract global warming and climate change. The use of ammonia with hydrocarbon fuels can limit the formation of soot and carbon emissions due to non-carbon atoms. The current study explores the use of ammonia with air at coflow flame conditions, which was not tested before. It may give the choice for diesel cycle engines to use the ammonia either with air or fuel. The combustion and emission characteristics of methane coflow flame were studied at low pressure and air polluted by ammonia conditions. The results showed that a significant decline in carbon formation was observed when ammonia was boosted, 5-10%. The impact of sub-atmospheric pressure, 90-70 KPa, on COx development was higher than that of NH3 addition, 0-5%, thanks to the lower formation of hydroxymethylium, formaldehyde, and aldehyde radical. In the environment of lower pressure, the

Hina, Anam, Akram, M Zuhaib, Shafa, Amna, Akram, M Waqar

Improved Three-Way Catalyst with Ignition Layer for Reducing Cold Emissions

2025-01-8482

04/01/2025

Exhaust gas regulations, such as Tier4, Euro7, and China7, are being strengthened. In addition to the regulated values during specified driving patterns, emissions must be minimized under various usage scenarios. Since vehicle catalysts have been using higher amounts of precious metals to satisfy these requirements, there is increasing demand to decrease the usage of these metals from the perspective of environmental protection. The exhaust gas emission is divided into cold emission and hot emission. Recently, improvements of cold emission have become a focus. This research focused on improving catalyst warm-up activity by positioning the palladium (Pd) layer above the rhodium (Rh) layer. At the same time, to resolve the decrease in gas utilization in the Rh layer, connectivity was enhanced, and the influence of sulfur components was suppressed through the optimization of the Pd support. As a result, the usage of precious metals has successfully lowered.

Nishio, Takahiro, Takagi, Nobuyuki, Tojo, Takumi, Fujita, Naoto, Mori, Mizuho, Toda, Yosuke

Study of the Effects on Plain Bearings in Simulated Corrosion Tests Using Carbon Neutral Fuels

2025-01-8470

04/01/2025

Many countries around the world are currently working toward carbon neutrality, which would reduce greenhouse gas emissions to net zero by 2050. To achieve carbon neutrality, the search for new fuels to replace gasoline has been active. This study focuses on hydrogen and methanol fuels and examines their effects on plain bearings when these fuels are used in internal combustion engines. Compared to gasoline, these fuels differ significantly in the composition of gases produced after combustion. It is assumed that nitric acid, etc. will be mixed in the engine oil when hydrogen is combusted whilst formic acid, etc. will be mixed in the engine oil when methanol fuel is combusted. For this reason, corrosion tests were conducted by adding nitric acid or formic acid solution to the engine oil then placing plain bearings in the deteriorated oil. The results confirmed that significant corrosion of the bismuth overlay coating occurred and subsequently the performance of plain bearings may

Kondo, Makoto, Kawaura, Hiroki, Shiroya, Tomoyasu, Watanabe, Airi

Study on Energy Consumption and Emission Characteristics of EHC Coupled DOC+SDPF+SCR-ASC System under WLTC and RDE

2025-01-8498

04/01/2025

With the tightening of emission regulations, Electrically Heated Catalyst (EHC) are an important technical solution for diesel vehicles to address the emission challenges of cold start and Real Driving Emission (RDE). This paper investigates the impact of EHC coupled exhaust aftertreatment system (Diesel Oxidation Catalyst (DOC) + Selective Catalytic Reduction Integrated into Diesel Particulate Filter (SDPF) + Selective Catalytic Reduction (SCR) - Ammonia Slip Catalyst (ASC)) on the energy consumption and emission characteristics of light-duty diesel vehicles based on the World Light Vehicle Test Cycle (WLTC) and RDE. The research results show that under WLTC conditions, compared to EHC off, the time for the SDPF inlet temperature to reach 180 °C when EHC on is 44 seconds earlier. The Carbon Monoxide (CO) emission of diesel vehicles is 63.5 mg/km, the Total Hydrocarbon (THC) emission value is 44.9 mg/km, the Non-Methane Hydrocarbon (NMHC) emission value is 39.5 mg/km, and the Nitrogen

Kang, Lulu, Zhao, Zhiguo, Lou, Diming

Prediction and Control of Long-Term System Degradation for a Light-Off SCR in an Ultra-Low NOx Aftertreatment System

2025-01-8488

04/01/2025

The heavy-duty low NOx program funded by EMA at Southwest Research Institute (SwRI) evaluates a combination of engine and advanced aftertreatment systems to achieve a 0.035 g/bhp-hr tailpipe NOx standard. This work emphasizes improvements to the light-off SCR (LO SCR) model used for low NOx controls. Two key mechanisms drive these improvements: the first is a real-time feedback system that utilizes the LO SCR outlet NOx sensor for short-term corrections to the model state, and the second involves adjustments to the dosing mechanism based on long-term trends in dosing signals compared to predicted NH3 consumption, derived from LO SCR inlet and outlet NOx sensors, referred to as long-term trim. An algorithm is incorporated to differentiate the LO SCR outlet NOx sensor readings into NOx and NH3 components based on cross-correlation between inlet and out NOx sensors termed as speciation. The integration of this speciation algorithm with both short-term and long-term trim mechanisms

Chundru, Venkata Rajesh, Adsule, Kartik, Sharp, Christopher

Decarbonization of Off-Road Engines by Methanol Mixing-Controlled Compression Ignition with Ignition Enhancer

2025-01-8411

04/01/2025

Methanol is one of the most promising fuels for the decarbonization of the off-road and transportation sectors. Although methanol is typically considered an alternative fuel for spark ignition engines, mixing-controlled compression ignition (MCCI) combustion is typically preferred in most off-road and medium-and heavy-duty applications due to its high reliability, durability and high-efficiency. In this paper, methanol MCCI combustion was enabled using ignition improvers and the potential benefits of this approach compared to conventional diesel combustion were investigated. Methanol was blended with 7%vol of 2-ethylhexyl nitrate (EHN) and experiments were performed in a single-cylinder production-like diesel engine with a displacement volume of 0.8315 L and a compression ratio of 16.5:1. The conditions of the ISO 8178 C1 regulatory cycle for off-road engines were tested, and performance and emissions over the cycle were calculated. Methanol MCCI shows 5.3% lower fuel consumption (in

Lee, Sanguk, Lopez Pintor, Dario, MacDonald, James, Narayanan, Abhinandhan, Chan, Adrian

Ignition and Combustion Improvement Via Ignition Modulation under Flow Conditions

2025-01-8403

04/01/2025

In order to reduce the environmental impact of transportation, the adoption of low and zero carbon fuel is needed to reduce the greenhouse gas emissions from engines, both from tailpipe and well-to-wheel perspectives. However, for some of the promising fuels, such as renewable natural gas and ammonia, the relatively low chemical reactivity and laminar flame speed bring challenge to a rapid and efficient combustion process, especially under lean or diluted conditions to suppress NOx emissions, leading to reduced combustion and thermal efficiencies. To tackle the challenge, high in-cylinder flow speed is needed to shorten the combustion duration, together with strong ignition sources to support the initial flame kernel development. In this paper, an ignition energy modulation system is developed to enhance both discharge current and discharge energy of a spark event to secure the ignition process. Moreover, a rapid compression machine is employed to compress the fuel-air mixture to the

Jin, Long, Yu, Xiao, Zhou, Qing, Reader, Graham, Li, Liguang, Zheng, Ming

Performance and Emissions Analysis of a Hydrogen-Powered Heavy-Duty High Compression Ratio SI Engine Across Various Loads and Speed at Ultra-Lean Condition

2025-01-8428

04/01/2025

With the global shift towards sustainable and low-emission transportation, hydrogen-fueled engines stand out as a promising alternative to traditional fossil fuels, offering significant potential to reduce greenhouse gas emissions. This study provides a comprehensive evaluation of the performance and emissions characteristics of a hydrogen-powered heavy-duty compression ignition engine, which has been modified to operate as a Spark Ignition (SI) engine with a high compression ratio of 17:1. The evaluation was conducted across various speeds, loads, and spark timings under ultra-lean combustion conditions. The analysis utilized a modified 6-cylinder, 13-liter Volvo D13 diesel engine, configured to operate in single-cylinder mode with the addition of a spark plug for SI operation. The study examined key performance metrics, including brake thermal efficiency (BTE), power output, and specific fuel consumption, under the selected operating conditions. Emissions profiles for nitrogen oxides

Dyuisenakhmetov, Aibolat, Panithasan, Mebin Samuel, Cenker, Emre, AlRamadan, Abdullah, Im, Hong, Turner, James

Effect of Fuels on Compression Ignition Engine Particle Number and Mass Emissions and DPF Filtration Efficiency

2025-01-8502

04/01/2025

As part of decarbonization, alternative fuels are likely to be used in compression ignition internal combustion engines as a substitute for diesel fuel. There have been many studies on the effect of these alternative fuels on emissions and catalytic aftertreatment systems. Past research has reported lower particulate matter (PM) and higher oxides of nitrogen (NOx) with biofuels. However, there are limited studies on the effect of PM on the performance of diesel particulate filters (DPFs), especially in its effectiveness of PM filtration. PM emissions from four (4) types of fuels and five (5) of their blends, a total of nine fuels, were investigated using PM2.5 mass, soot mass, solid particle number (> 10 nm SPN10 and > 23 nm SPN23) and size distribution (6 nm to 560 nm) measurements at inlet and outlet of a DPF. The PM emissions were measured over a non-road regulatory cycle sequence consisting of five (5) non-road transient cycles (NRTCs) and five (5) non-road steady-state cycles

Lakkireddy, Venkata, Khalek, Imad, Buffaloe, Gina

Theoretical Study of Electrically Assisted Two-Stage Turbocharger Boost System Applied to Large-Bore Gas SI ICE

2025-01-8354

04/01/2025

Large-bore gas SI ICEs are supposed to operate under more strict conditions in terms of NOx level and potentially using new generation of fuels (e.g., hydrogen, ammonia) in the near future. Currently, the TA Luft norm is being considered while typical BMEP levels are between 22-28 bar. It is expected that NOx will have to drop significantly (down to 20% or even below 10% of the amount based on TA Luft) while engine BMEP is supposed to be increased above 30 bar. The paper is based on 0-D/1-D simulations while using the experience gained from older research projects concerning similar engines. The main goal is to study the influence of different operating conditions (e.g., NOx level, BMEP level, control means, ambient conditions) on both ICE performance and turbocharger operation while comparing classical 2-stage system with 2 electrically assisted ones (e-turbo, e-booster) – steady state performance is of the main focus while transient one is also considered. Complex optimizations were

Vitek, Oldrich, Macek, Jan, Mares, Bohumil, Klima, Jiri, Vacek, Martin

Experimental and Numerical Investigation of Different Dilution Techniques in a High-Performance H2 - Fueled SI Engine

2025-01-8424

04/01/2025

Nowadays, hydrogen (H2) is rising as a key solution to fuel internal combustion engines (ICE) since it allows carbon free combustion process. At the same time, ICE fueled with H2 can reach similar performance and driving experience of gasoline fueled ones. In stoichiometric conditions, hydrogen shows higher flame speed, lower ignition energy and lower quenching distance than gasoline. Mainly for these reasons, H2 combustion is characterized by a high risk of abnormal combustion (i.e. knock and pre-ignition), relevant NOx emissions and high heat losses. On the other hand, the wide flammability range and high combustion stability of H2 allow the use of different techniques to reduce combustion reactivity. This work presents a combined approach, experimental and numerical, to assess the benefits of three mixture dilution methods. The experimental campaign, in different operating conditions, was carried out on a production derived high specific power gasoline Single Cylinder Engine (SCE

Tonelli, Roberto, Medda, Massimo, Gullino, Fabrizio, Silvestri, Nicola, Zaffino, Francesco, Mariconti, Roberto, Rossi, Vincenzo

A Computational Investigation of Hydrogen Pre-Chamber and Spark-Ignition Combustion Engines at Different Load Conditions

2025-01-8406

04/01/2025

Pre-chamber (PC) technology has demonstrated its capability to achieve clean and stable combustion in internal combustion engines (ICEs) under lean conditions. This study evaluates the effectiveness of PC in direct injection (DI) hydrogen (H2)-ICEs compared to conventional spark ignition (SI) operation using high-fidelity computational fluid dynamics simulations across a range of load conditions. Various loads were attained by systematically adjusting intake pressure and injected H2 mass. The primary hypothesis posits that highly turbulent PC jets facilitate rapid mixing and combustion of ultra-lean mixtures. The comparative analysis revealed that DI fueling in both PC and SI modes did not achieve perfectly homogeneous mixtures, particularly under high load conditions, although PC slightly enhanced mixture uniformity. Combustion behavior exhibited a non-monotonic trend, with SI outperforming PC at low and high loads, while PC demonstrated superior performance at medium loads despite

Menaca, Rafael, Liu, Xinlei, Mohan, Balaji, Cenker, Emre, AlRamadan, Abdullah, Im, Hong

Effect of Geometrical Manipulation of the Pre-Chamber Design Parameters on the Combustion Performance of an Argon Power Cycle Engine

2025-01-8405

04/01/2025

Most of the power produced by manufacturing industry in the United States is via combined heat and power (CHP) systems, with most CHP installations using reciprocating internal combustion engines (RICE). RICE CHP systems offer several advantages, such as low installation and operational costs, high performance, load flexibility, and adaptability to various applications spanning from kilowatt to megawatt scales. Noble Thermodynamic Systems' (NTS) core technology, the Argon Power Cycle (APC), is a revolutionary, new power generation system that boosts the efficiency of RICE CHP generation systems while emitting zero greenhouse gasses or producing zero air pollutants, including nitrogen oxides (NOx). The APC uses the noble gas argon, a monatomic gas, which dramatically increases the specific heat ratio of the working fluid, resulting in a significantly higher ideal Otto cycle efficiency. The APC presents a promising solution to reach a carbon-neutral future for the energy needs of pivotal

Sharma, Eshan, Kim, Joohan, Strickland, Tyler, Scarcelli, Riccardo, Beardsell, Guillaume, Nilsen, Christopher, Sierra Aznar, Miguel

Research on the Combustion Characteristics of Gasoline Compression Ignition (GCI) Engine Based on Quasi-Homogeneous Mixture Charge Activity Control

2025-01-8409

04/01/2025

High-octane fuel presents significant potential for enhancing the efficient and clean combustion of small GCI engines. To achieve both efficient and stable combustion during low load scenarios, this study employs the combination of simulation and experimental methodologies. By coordinating the mixing rate and chemical reaction rate, as well as optimizing the equivalent ratio, temperature inhomogeneity and other parameters, introduces a control strategy termed ‘gasoline-air’ control coupling quasi-homogeneous mixture multi-pulse charge activity control. The research indicates that a quasi-homogeneous mixture can be formed through pilot injection of gasoline during the intake stroke, with low injection pressure can enhance charge activity and promoting clean combustion. The optimal injection timing is identified at approximately -315 CA ATDC, where appears peak value of indicated thermal efficiency. The multi-pulse charge activity control strategy can effectively control the combustion

Nie, JinLong, Yi, Yucheng

Experimental Study of DOC-on-Filter Using Next Generation Filter Solutions for Non-Road Applications

2025-01-8479

04/01/2025

Upcoming California Tier 5 non-road limits mandate 90% and 75% reductions in NOx and PM respectively, from current Tier 4F emission standards. Similarly, lower NOx and PN/PM limits can be expected from a next round of European Non-Road regulations. To meet these limits, more SCR volume for greater NOx reduction, and better filtration efficiency filters for greater PN/PM reduction, may be required. The challenge is to accommodate larger SCR volume while maintaining oxidation (DOC) and filtration (DPF) functionality of the aftertreatment system within a limited packaging space on non-road machineries. Consolidating DOC and DPF into a single component as DOC-on-filter instead of separate DOC and DPF substrates to achieve space saving has been previously discussed in literature. This study expands on the current understanding and explores various functional performance characteristics of the DOC-on-filter concept in comparison with DOC + bare DPF, DOC + PGM coated DPF. The three test

Dam, Mrinmoy, Warkins, Jason, He, Suhao

Effect of Catalyst Coating Strategy on NOx Reduction and Passive Soot Oxidation for Selective Catalytic Oxidation-Selective Catalytic Reduction Catalyst on Diesel Particulate Filter

2025-01-8490

04/01/2025

Selective catalytic oxidation/reduction catalysts coated on diesel particulate filters (SDPF) are an important technology route to meet next-stage emission regulations. The previous research of the research group showed that compared with SDPF coated with Cu-SSZ-13, the SDPF coated with novel selective catalytic oxidation-selective catalytic reduction (SCO-SCR) catalyst, which combined MnO2-CeO2/Al2O3 and Cu-SSZ-13, can simultaneously improve NOx reduction and soot oxidation performance. Catalyst coating strategy is an important parameter affecting the performance of SDPF. In this study, the effects of different coating strategies of SCO-SCR catalysts (C25, C50, C75, and C100) on the performance of NOx reduction and soot oxidation in SDPF were investigated. The results show that, as the inlet gas temperature increases, NO emissions first decrease and then increase, NOx conversion efficiency first increases and then decreases, and the rich-NO2 area, NH3 oxidation rate, N2O, CO, CO2

Chen, Ying-jie, Tan, Piqiang, Yao, Chaojie, Lou, Diming, Hu, Zhiyuan, Yang, Wenming

Advanced Aftertreatment System Meeting Future HD CNVII Legislation II

2025-01-8478

04/01/2025

With the increasing clarity of the CNVII emission legislation, it is foreseeable that CNVII will further tighten the emission limits of major pollutants such as Nitrogen Oxide (NOx), Nitrous Oxide (N2O) and Particulate Number (PN). Together with the implementation of stage IV fuel consumption legislation in July 2025, which requires engine fuel consumption reduction or thermal efficiency improvement, it will lead to further deterioration of its pollutant emissions and reduction of exhaust temperature, posing greater challenges to the After-Treatment System (ATS) in terms of NOx removal, particularly during engine cold start and N2O formation suppression. This study is an extension of our earlier investigation [1], and a novel copper-based corrugated SCR (Full Body-CuSCR, FB-CuSCR) technology was successfully applied. The results based on a modified CNVI medium duty engine indicated excellent dynamic response of the FB-CuSCR technology over cordierite which helped to improve the

Wang, Yan, Fu, Guangxia, Chen, Shuyue, Aberg, Andreas, Jiang, Shuiyan, Zhang, Jun

Operating the Tour Split-Cycle Engine on Hydrogen/Methane Fuel Blends to Achieve High Efficiency and Reduction of Both GHG and NOx Emissions

2025-01-8422

04/01/2025

Decarbonized or low carbon fuels, such as hydrogen/methane blends, can be used in internal combustion engines to support ambitious greenhouse gas (GHG) emission reduction goals worldwide, including achieving carbon neutrality by 2045. However, as the volumetric concentration of H2 in these fuel blends surpasses 30%, the in-cylinder flame propagation and combustion rates increase significantly, causing an unacceptable increase in nitrogen oxides (NOx) emissions, which is known to have substantial negative effects on human health and the environment. This rise in engine-out NOx emissions is a major concern, limiting the use of H2 fuels as a means to reduce GHG emissions from both mobile and stationary power generation engines. In this study, an experimental investigation of the combustion performance and emissions characteristics of a 4th generation Tour split-cycle engine was undertaken while operating on 100% methane and various hydrogen/methane fuel blends (30%, 40%, and 50% by volume

Bhanage, Pratik, Cho, Kukwon, Anderson, Bradley, Kemmet, Ryan, Tour, Gilad, Atkinson, Chris, Tour, Hugo, Tour, Oded

Effects of Combustion Characteristic Parameters on Emission Performance in Ammonia-Hydrogen Internal Combustion Engine

2025-01-8425

04/01/2025

Under the background of the global dual carbon target, ammonia and hydrogen as the carbon-free fuel, have become a research hotspot for internal combustion engines. The existing researches mainly focus on the combustion characteristics influenced by equivalence ratio, hydrogen jet ignition and so on, while the relationship between combustion and emission characteristics should be also paid more attention. In this paper, the impact of combustion characteristic parameters on engine emissions is investigated by GT-power. The simulation model is based on a single cylinder engine with an active pre-chamber. Meanwhile, combustion characteristic parameters, in terms of CA50, combustion duration, CA10-CA50 and CA50-CA90 are set referred to the research of hydrogen jet ignition ammonia-hydrogen internal combustion engines. The results shown that there is compelling correlation between combustion parameters and specific emission profiles in ammonia-hydrogen internal combustion engines. Notably

Yuan, Yang, Shang, Quanbo, Deng, Jun, Li, Liguang, Yin, Xuemei, Lai, Huilong, Ma, Jiangli, Yu, Fei, Feng, Feng, Cui, Hao, Du, Junchen

Optimizing Hybrid Powertrains for Light Duty Commercial Vehicles

2025-01-8544

04/01/2025

Battery electric vehicles (BEVs) are well-suited for many passenger vehicle applications, but high cost, short range, and long recharging times have limited their growth in commercial vehicle markets. These constraints can be eliminated with plug-in hybrid electric vehicles (PHEVs) which combine many benefits of BEVs with those of conventional vehicles. In this study, research was conducted to determine the optimal hybrid electric powertrain system for a Class 3, light duty commercial vehicle. The key technologies used in this hybrid powertrain include engine downsizing, P3 architecture hybridization, and active thermal management of aftertreatment. A vehicle cost of ownership analysis was conducted to determine the economic viability, a very important consideration for commercial vehicles. Several combinations of E-motor and battery pack sizes were evaluated during the cost analysis and the best possible configuration was determined. The resulting vehicle powertrain demonstrated ~60

Meruva, Prathik, Michlberger, Alexander, Bachu, Pruthvi, Bitsis, Daniel Christopher

Comprehensive Investigation of Combustion Characteristics, Emissions, and Tribological Properties of Synthetic Kerosene (S8) in a CVCC and CRDI Research Engine

2025-01-8443

04/01/2025

There is a need to reduce both the greenhouse gas emissions of internal combustion engines, and the reliance on traditional fossil fuels like Ultra Low Sulfur Diesel (ULSD). In this research, a synthetic paraffinic kerosene fuel, designated S8 and created from natural gas feedstocks using the Fischer-Tropsch process was investigated to determine its autoignition and combustion characteristics, emissions, and tribological properties. This fuel, S8, was found to have a Derived Cetane Number (DCN) of 62, which reflects a shorter Ignition Delay (ID), and Combustion Delay (CD) compared to ULSD, which has a DCN of 48. However, due to the chemical properties of S8, it lacks sufficient lubrication qualities in comparison to ULSD, so addition of 3% methyl oleate by mass was used to improve lubricity. The shorter ignition delay of S8, initially observed in a Constant Volume Combustion Chamber (CVCC) and confirmed in a fired Common Rail Direct Injection (CRDI) experimental engine. Investigations

Soloiu, Valentin, Willis, James, Norton, Coleman, Davis, Zachary, Graham, Tristan, Nobis, Austin

Calculation of Airflow through the Air Cycle Technology’s Turboexpander and Its Effects on a Diesel Engine—Part I

2025-01-5023

03/31/2025

Amidst escalating climate change, the sustainability of internal combustion engine (ICE) vehicles, particularly in heavy transport, remains a critical challenge. Despite emission reductions from 1990 to 2020, ICEs, particularly diesel engines in Europe, continue to pose environmental challenges, notably in nitrogen oxide (NOx) emissions. This study proposes a novel solution to address the problem of NOx emissions by incorporating Air Cycle Technology’s (ACT) turboexpander into diesel engines. Acting as a second-stage compressor, intercooler, and expander, the turboexpander aims to lower intake air temperature, thereby mitigating NOx formation. The study utilizes a 4.4-l JCB-TCA-74 turbocharged diesel engine retrofitted with the ACT turboexpander as the experimental platform. The methodology involves using empirical formulae to calculate the key parameters of engine airflow for a standard turbocharged diesel engine followed by repeating the calculations for the same engine fitted with a

Fayaz, Farheen, Brace, Jordan, Allport, John, Javanbakht, Gina

Experimental Analysis of Soot and NOx Mitigation during Energy-Buffered Diesel Engine Transients

03-18-02-0014

03/24/2025

Transient operation of a diesel-fueled compression ignition engine will produce significant levels of engine-out criteria pollutants such as NOx and soot emissions due to turbocharger lag. Conventional pollutant mitigation strategies during tip-ins (large increases in load) are constrained by the soot–NOx trade-off—strategies that mitigate soot/NOx emissions often result in an increase in NOx/soot emissions. Hybridization offers the ability to use an e-machine as an energy buffer during a tip-in, allowing the engine to tip-in slower to give the turbocharger time to spin up and provide the necessary amount of air for clean, high-load operation. In this work, an in-line six-cylinder 12.8 L Detroit Diesel DD13 engine was used to study the impact of slowing the torque ramp rate of a tip-in on the effectiveness of transient emission reduction strategies for turbocharged diesel engines, including exhaust gas recirculation (EGR) valve closing, start of injection retard, and the air–fuel ratio

Gainey, Brian, Datar, Aditya, Bhatt, Ankur, Lawler, Benjamin

Research on NOx Emission Prediction Model for Delivery Trucks Based on Machine Learning and Its Application in Smart Transportation

2025-01-7180

02/21/2025

With the rapid development of smart transport and green emission concepts, accurate monitoring and management of vehicle emissions have become the key to achieving low-carbon transport. This study focuses on NOx emissions from transport trucks, which have a significant impact on the environment, and establishes a predictive model for NOx emissions based on the random forest model using actual operational data collected by the remote monitoring platform.The results show that the NOx prediction using the random forest model has excellent performance, with an average R2 of 0.928 and an average MAE of 43.3, demonstrating high accuracy. According to China's National Pollutant Emission Standard, NOx emissions greater than 500 ppm are defined as high emissions. Based on this standard, this paper introduces logistic regression, k-nearest neighbor, support vector machine and random forest model to predict the accuracy of high-emission classification, and the random forest model has the best

Lin, Yingxin, Li, Tiezhu

Mitigating Carbon Dioxide Emissions in Diesel Engines through the Application of Physical Adsorbents

2025-01-5008

02/13/2025

Graphical Abstract Abstract The world is targeting zero-emission standards by promoting flexi-fuel-based vehicles. In the automotive industry, IC engine-powered vehicle has a good market. Either IC or flexi-fuel engines are considered the safest mode of transport, one tedious problem needs to be addressed is their toxic exhaust emissions from those engines. However, there are many aftertreatment systems available to control HC, CO2, NOx, and PM emissions. To control CO2 emissions there is no aftertreatment system available. Physical adsorbents such as activated carbon and zeolite are going to be used in this work to reduce emissions from exhaust gases. Zeolite has a greater affinity toward NOx emission, and activated carbon has greater potential to capture HC and carbon dioxide emissions. Initially computational studies were carried out to evaluate back pressure developed in adsorbent chamber. Analysis was carried out by varying conical length of the adsorbent chamber (68 mm, 75 mm

Subramanian, MohanKumar, Muthiya, Solomon Jenoris, Pachamuthu, Senthilkumar, Naveena, B. E., Divya, G. S., Praveen Kumar, M. V.

SAE Truck & Off-Highway Engineering: February 2025

25TOFHP0202/13/2025

Deere advances off-highway autonomy John Deere revealed its second-generation tech stack and four new autonomous machines to the public at CES 2025. Hybrid powertrains in the product mix Hybridization and alternative fuels catching on as carbon-reduction targets intensify and infrastructure challenges persist for on-highway trucks. The intersection of autonomy and cybersecurity New automated safety features and increased connectivity require truck and off-highway OEMs to prioritize vehicle security and minimize cyber threats. Editorial Not quite your father's cab CES 2025: Oshkosh puts AI, autonomy and electrification to work CES 2025: Cat debuts hybrid-electric retrofit on 972 wheel loader Bosch sees two paths forward for on-road hydrogen trucks Study: Excessive real-world NOx emissions from HD diesel pickups AVSC develops best practices for traceable AV safety inspection protocols JLG reveals new E313 electric telehandler Freightliner develops safer, sleeker fifth-gen Cascadia GM

Study on the Impact of Arrangement of Urea Injector and Mixer in Diesel Engine Selective Catalytic Reduction System on Ammonia Uniformity

02-18-02-0007

02/12/2025

With the continuous upgrading of emission regulations for internal combustion engines, the nitrogen oxide treatment capacity of selective catalytic reduction (SCR) aftertreatment needs to be continuously improved. In this study, based on a prototype of SCR aftertreatment, the impact of the arrangement of key components in the SCR system (urea injector, mixer, and catalyst unit) on ammonia uniformity was investigated. First, parameterized designs of the urea injector, mixer, and SCR unit were conducted. Then, using computational fluid dynamics (CFD), numerical simulations of the established aftertreatment system models with different parameter factors were performed under a high-exhaust temperature and a low-exhaust temperature conditions to study the impact of each individual parameter on ammonia uniformity. Finally, an optimized solution was designed based on the observed patterns, and the optimized samples were tested on an engine performance and emission test bench to compare their

Jie, Wang, Jin, Jianjiao, Wu, Yifan

Cutting-Edge Coating Materials for Dual Fuel Diesel Engines Using Acetylene Aspiration

2025-28-0134

02/07/2025

A diesel engine with a Yttria Stabilised Zirconium (YSZ) thermal barrier layer (TBL) on the piston crown was used in an experiment. The aim of the investigation was to evaluate the influence of the thermal barrier layer on the efficiency and pollution levels of a diesel engine. The selection of YSZ as the coating material was based on its desirable physical properties including a high coefficient of expansion when exposed to heat, low degree of thermal conductivity, and a high Poisson's number. These characteristics make it a suitable material for use in coatings applied to engine components. In addition to their current research, the scientists are also focusing on identifying sustainable substitutes for conventional petroleum fuels. This is because of the growing concern over environmental impacts and the limited availability of fossil fuel resources. The researchers are seeking new options that are both environmentally friendly and capable of meeting the world's energy demands. By

Sagaya Raj, Gnana, Natarajan, Manikandan, Pasupuleti, Thejasree

An Integrated Material Science Approach to Evaluate the Viability of Ethoxy Ethane and Rubber Seed (Heavea Brasiliensis) Biodiesel as Sustainable Fuel for Compression Ignition Engines

2025-28-0130

02/07/2025

The primary issues in using pure vegetable oils for internal combustion engines are their high soot output and reduced thermal efficiency. Therefore in the present investigation, a Heavea Brasiliensis biodiesel (HBB) is used as a carbon source of fuel and ethoxy ethane as a combustion accelerator on a compression ignition (CI) engine. In this investigation, an only one cylinder, four-stroke, air-cooled DI diesel engine with a rated output of 4.4 kW at 1500 rpm was utilized. Whereas heavea brasiliensis biodiesel was delivered straightly into the cylinder at almost close to the end of compression stroke and ethoxy ethane was sprayed instantly in the intake manifold in the event of intake stroke. At various loads, the parameter of ethoxy ethane volume rate were optimised. To minimise exhaust emissions, an air plasma spray technology was employed to cover the engine combustion chamber with a thermal barrier coating. Because of its adaptability for high-temperature applications, YSZ (Yttria

Sagaya Raj, Gnana, Natarajan, Manikandan, Pasupuleti, Thejasree

Impact of Hydrogen Enrichment on Performance and Emissions Characteristics of a Compression Ignition Engine Operated in Dual Fuel Mode with Karanja Oil Methyl Ester-Tire Pyrolysis Oil Blend

2025-28-0109

02/07/2025

The growing demand for fossil fuels and the search for alternatives have the potential to reduce emissions and enhance energy security. Karanja oil and tire pyrolysis oil (TPO) are identified as promising substitutes. This study examines the performance and emission characteristics of a 5.2 kW, 1500 rpm, four-stroke single-cylinder compression ignition engine. The engine was tested using diesel, the optimal combination of Karanja oil biodiesel (KOME) and TPO (50:50% volume ratio), and this KOME-TPO blend with hydrogen supplied in dual fuel mode at flow rates of 10 lpm, 20 lpm, and 30 lpm, designated as H10, H20, and H30, respectively. The results indicated that BTE for H30 was the highest, reaching 32.21% compared to 30.52% for diesel at 5.2 kW BP. BSEC for H30 was the lowest at 11.18 MJ/kWh, compared to 11.80 MJ/kWh for diesel at the same BP. Emission analysis showed that smoke and HC emissions were significantly lower for hydrogen-enriched blends. At 5.2 kW BP, HC emissions for H30

Duraisamy, Boopathi, Stanley Martin, Jerome, Chelladorai, Prabhu, Rajendran, Silambarasan, Marutholi, Mubarak, Madheswaran, Dinesh Kumar

Performance and Emission Analysis of a CI Engine Using Various Blends of Diesel and Prosopis Juliflora Seed Oil-Derived Biodiesel

2025-28-0129

02/07/2025

The rising demand for fossil fuels and the exploration of renewable energy sources from plants have gained significant attention due to their role in reducing emissions and enhancing energy security. Prosopis juliflora, abundantly available in India, offers a viable source for biodiesel production. This study investigates the performance and emission characteristics of a 5.2 kW, 1500 rpm, four-stroke single-cylinder compression ignition (CI) engine using blends of diesel, vegetable oil, and biodiesel derived from Prosopis juliflora seeds. The engine was tested with pure diesel, vegetable oil (PJO), biodiesel (B100), and biodiesel-diesel blends at 20%, 40%, 60%, and 80% by volume, designated as B20, B40, B60, and B80, respectively. Key performance metrics, including brake thermal efficiency (BTE) and brake specific energy consumption (BSEC), were measured, along with emissions such as carbon monoxide (CO), smoke, hydrocarbons (HC), and nitrogen oxides (NO). Results indicated that BTE

Duraisamy, Boopathi, Stanley Martin, Jerome, Thiyagarajan, Prakash, Rajendran, Silambarasan, Marutholi, Mubarak, John, Godwin

Prediction of Diesel Engine NO _x Transient Emissions Based on a Combined Model with Convolutional Neural Network–Efficient Channel Attention–Bidirectional Gated Recurrent Unit

03-18-02-0012

02/06/2025

Widely used as power equipment, diesel engines emit NO x , which significantly threatens the well-being of both the ecosystem and individuals. The SCR system, which is employed to reduce NO x emissions from diesel engines, relies on precise control of the NO x emission levels. Addressing the challenge that traditional NO x emission prediction methods struggle to accurately forecast the emissions under transient operating conditions, this article introduces a deep learning model that integrates CNN, ECA, and BIGRU. The model’s necessary experimental data were collected during the hot phase of the WHTC, and input parameters were screened through correlation analysis. The model employs a CNN for feature extraction, integrates an ECA module to refine key feature processing, and utilizes BIGRU to capture temporal dynamics and dependencies, yielding predictive outcomes. Additionally, the model employs the Adam optimizer and combines it with BWO to adjust hyperparameters, thereby elevating

Peng, Yunlong, Wang, Guiyong, Wang, Yuhua, Wang, Feiyang, Wang, Zhiyuan, He, Shuchao

The Influence of Excess Air Ratio on NOx Emissions of Turbocharged Direct Injection Hydrogen Internal Combustion Engines

2025-01-7094

01/31/2025

Direct injection in the cylinder of a hydrogen internal combustion engine results in increasing NOx emissions in high-temperature oxygen rich environments. To explore the effect of excess air ratio λ on the NOx emissions of a direct injection hydrogen fueled internal combustion engine (HICE), a CFD simulation model was built based on a turbocharged direct injection hydrogen internal combustion engine using Converge software, and investigates the impact of lean burn on the NOx emissions. The simulation results show that increasing the excess air ratio λ can lower the in-cylinder mean temperature and effectively reduce the generation of NOx. The maximum temperature difference between λ=2.1 and λ=2.7 is 400K when engine speed is 4500 r/min. As the engine speed increases, under the same condition of λ, different loads at different speeds result in differences in the reaction temperature inside the cylinder, with higher temperatures at high speeds, so both the cylinder temperature and NOx

Peng, Tianyu, Luo, Qinghe, Tang, Hongyang

Effect of Injection Pressure and Equivalent Ratio on Combustion and Emissions of The Ammonia/Diesel Dual Fuel Engine

2025-01-7111

01/31/2025

In the context of low-carbon and zero-carbon development strategies, the transformation and upgrading of the energy structure is an inevitable trend. As a renewable fuel, ammonia has a high energy density. When ammonia is burned alone, the combustion speed is slow. The emissions of nitrogen oxides and unburned ammonia is high. Therefore, a suitable high-reactivity combustion aid fuel is required to improve the combustion characteristics of ammonia. Based on this background, this study converted a six-cylinder engine into a single-cylinder ammonia/diesel dual-fuel system, with diesel fuel as the base and a certain percentage of ammonia blended in. The impact of varying the injection pressure and equivalence ratio on engine combustion and emissions was examined. The results demonstrate that an appropriate increase in injection pressure can promote fuel-gas mixing and increase the indicated thermal efficiency (ITE). With regard to emissions, an increase in injection pressure has been

Wang, Hu, Lv, Zhijie, Zhang, Shouzhen, Wang, Mingda, Yang, Rui, Yao, Mingfa

Experimental Study on the Effects of Ammonia Energy Substitution Rate on Combustion and Emission Performance in a Hydrogen Engine

2025-01-7105

01/31/2025

To advance the application of zero-carbon ammonia fuel, this paper presents an experimental investigation on the potential of ammonia substitution using a 2.0L ammonia-hydrogen engine, where ammonia is injected into the intake port and hydrogen is directly injected into the cylinder. The study examines the effects of ammonia substitution rate under various load conditions on engine combustion and emission performance. Results indicate that the maximum ammonia energy substitution rate reached 98%, and within the stable combustion boundary, the mass fraction of unburned ammonia was less than 3%. The ammonia energy substitution ratio increased with load, and ammonia addition significantly suppressed pre-ignition and knocking. As ammonia content increased, ignition timing advanced, combustion duration extended, ignition delay prolonged, COV increased, peak cylinder pressure, and pressure rise rate decreased, with a corresponding decrease in peak heat release rate. Compared to a pure

Wu, Weilong, Xie, Fangxi, Chen, Hong, Du, Jiakun, Li, Yong

Enhanced High-Temperature Performance of NH ₃ -SCR Catalysts for Lean-Burn Engines

2025-01-7043

01/31/2025

NOx after-treatment has greatly limited the development of lean-burn technology for gasoline engines. NH3-Selective Catalytic Reduction (SCR) technology has been successfully applied to NOx conversion in diesel engines. For gasoline engines, SCR catalyst is required to maintain high activity over a higher temperature window. In this study, we utilized a turbocharged and intercooled 2.0 L petrol engine to investigate the NOx conversion of two zeolite-based SCR catalysts, Cu-SSZ-13 and Fe/Cu-SSZ-13, at exhaust flows ranging from 80 to 300 kg/h and exhaust temperatures between 550 to 600°C. The catalysts were characterized using SEM, ICP, XRD, H2-TPR, NH3-TPD, and other methods. The selected Fe/Cu-SSZ-13 catalyst showed higher NOx conversion (>80%) in the temperature range of 550~600oC and 80~300 kg/h exhaust gas flow. NOx output could be controlled below 10ppm. The characterization results showed that although the specific surface area and acidic sites decreased after the aging treatment

Pan, Shiyi, Wang, Ruwen, Zhang, Nan, Xu, Zhiqin, Hu, Jiangtao, Liao, Xiuke, Duan, Pingping, Chen, Ruilian

First Principle Study of Catalyst’s Influence on Self-Inhibition Effect and By-Products Formation of Lean NOx Trap

2025-01-7042

01/31/2025

Lean NOx trap is a dedicated DeNOx catalyst for lean hybrid gasoline engines. Noble metals (usually platinum group metals) play the role of catalytic sites for NOx oxidation and reduction, which have significant impact of the performance of LNT. This work focuses on the influence of noble metal catalysts on self-inhibition effect from the view of competitive adsorption between NO and CO, and investigates the influence of CO self-inhibition effect on the main by-product of LNT: N2O formation. Adsorption configurations for NO, CO and N2O on noble metal clusters supported by γ-Al2O3(100) are confirmed. For detailed investigation, electron structures are analyzed by investigating Bader charge, DOS (density of state), charge density differences and COHP (crystal orbital Hamilton population) of selected configurations.The results show that CO self-inhibition effect is caused by competitive adsorption between CO and NO. The essence of competitive adsorption between CO and NO is that

Liu, Mingli, Liu, Yaodong, Qu, Hanshi, Duan, Jiaquan, Zhang, Qiqi, Qian, Dingchao, Wang, Zhenxi, He, Zhentao

Emission and Economic Characteristics of Diesel/PODE Blended Fuel in Actual Road Driving

2025-01-7115

01/31/2025

Diesel/Polymethoxy Dimethyl Ether (PODE) blend fuel can significantly reduce emissions from diesel engines. However, emission levels often vary due to high transients during real-world driving conditions. To evaluate the emission and economic performance of diesel/PODE blend fuel, this study analyzed the real-world driving behavior of heavy tractors using different blend ratios (0%, 20%, 30%) across urban, suburban, and expressway road sections, in compliance with the national VI emission standard. Based on Vehicle Specific Power (VSP) bins, the study compared carbon monoxide, carbon dioxide, nitrogen oxide, particulate matter, and fuel consumption rates between pure diesel and blended fuels, providing insights into their performance under varying driving conditions. In addition, specific emissions of pollutants, effective fuel consumption, and effective thermal efficiency for urban, suburban, and expressway sections, as well as for the entire test process, are analyzed to quantify the

Liu, He, Yang, Yajing, Farooq, Muhammad Shahid, Liu, Shenghua, Wei, Yanju

Flash Boiling Impact on Spray, Flame, Emissions, and Soot of Gasoline-Acetone-Butanol-Ethanol Blend at Simulated Cold-Start GDI Operation Using a CVCC

2025-01-7046

01/31/2025

The use of carbon-neutral fuels instead of conventional fuels in gasoline direct injection (GDI) engines is beneficial to global decarbonization. However, the application of renewable non-petroleum fuels in GDI engines is still unclear due to their different physicochemical properties. Acetone-Butanol-Ethanol (ABE) is a promising low-carbon alternative fuel for GDI engines, but its high viscosity and latent heat cause pool firing during cold start. The existing flash boiling technology can solve this problem. This study explores the effects of flash boiling on spray characteristics, flame propagation, soot, and emissions of gasoline-ABE blend in a constant volume combustion chamber (CVCC) without airflow. Optical windows, high-speed camera recording, in-chamber pressure measurement, Fourier transform infrared spectroscopy (FTIR), and transmission electron microscope (TEM) were used to analyze flame spreading, combustion characteristics, exhaust gases, and soot morphology. Flash boiling

Nour, Mohamed, Zhang, Weixuan, Cui, Mingli, Li, Xuesong, Xu, Min, Qiu, Shuyi

Performance Analysis of Graphene-Coated Heat Pipe Heat Exchangers for Automobile Exhaust Cooling and Purification

2025-01-5006

01/23/2025

This research investigates the development of a heat pipe heat exchanger coated with graphene for cooling and purification of automobile exhausts. The heat exchanger directly affects the performance of the engine because proper heat dissipation and transfer can improve engine performance, reduce fuel consumption, and decrease the emission. Moreover, this effect is much more noticeable on coated heat pipes because of the enhanced thermal conductivity and mechanical properties of the graphene films. A heat null emitted by internal combustion engines was used in the experimental setup to test the thermal performance, cooling efficiency, and purification efficiency of the newly designed in-house exhaust simulation system where the new heat pipes were inserted. The results of the experiment show that the heat pipes have very high thermal performance as the efficiency of the heat pipes was calculated to be around 85%. Furthermore, the temperature decrease over the surfaces of the heat

Karthigairajan, M., Seeniappan, Kaliappan, Balaji, N., Natrayan, L., Sheik, Salman Basha, Ravi, D.

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