Browse Topic: Emissions

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Design and Simulation of Mobile Straw Carbonization Equipment2026-99-12659/4/2026
Straw is one of the major biomass energy sources. It has low economic benefits by conventional disposal methods, such as returning to the field, using as feed, pressing into block fuel, gasification power generation, papermaking, and manufacturing building materials. With the surplus of crop straw, a large amount of straw resources will be burned, resulting in severe resource waste, soil structure damage, and air pollution. Straw carbonization technology and equipment are effective measures to solve the problem of straw surplus. This paper proposes a mobile straw carbonization technology, studies the principles and processes of straw carbonization, and designs a high-efficiency mobile carbonization equipment that can be used in the field to reduce the costs of straw collection, transportation, and storage and realize the transformation of straw from waste to valuable resources. A mathematical model for the pyrolysis process of straw pellets was established. The structure of the mobile straw carbonization equipment was designed based on the research on the mechanism of straw pyrolysis and carbonization. A multi-layer sleeve rotary structure of the reactor is adopted, and the furnace body solves the problem of uneven heating of carbonization with a mixed feeding design of screws and scrapers. Simulation and experiments were conducted using corn straw as the raw material to analyze the variation law of temperature inside the furnace and verify the feasibility of the equipment designed for straw carbonization.
Shang, Chunmin, Yu, Jiadong
Research on Online Zero-Point Calibration Technique for Ω-Shaped Coriolis Flowmeters in CCUS Applications2026-99-12379/4/2026
The Ω-shaped Coriolis flowmeter, owing to its suitability for high-pressure and wide-temperature conditions, has become the preferred device for CO2 metering in CCUS-EOR projects. In practical applications, however, the volatile nature of operating pressures and temperatures triggers a persistent zero-point drift. This instability creates a ripple effect: it not only degrades metering precision but also fundamentally undermines the equitable basis of carbon trading markets. This study, through theoretical analysis, fluid-structure coupling simulation, and experiments, deeply investigates the patterns of zero-point drift in Ω-shaped Coriolis flowmeters and corresponding correction methods. The research reveals that the asymmetry of the measuring tube structure is the primary cause of zero-point drift, with changes in the vibration frequency of the measuring tube directly influencing the zero-point value, leading to the establishment of a related zero-point drift model. Based on the asymmetric structure of a DN15 Ω-shaped Coriolis flowmeter, simulations were performed to model the zero-point variation patterns under different pressures and temperatures using CO2 as the fluid, thereby verifying the effectiveness of the zero-point drift model. To validate our approach, we executed targeted zero-point experiments, employing the proposed model to predict zero-point shifts across a broad spectrum of pressures and temperatures. By integrating these predictions into a refined correction framework, we successfully neutralized drift-induced errors. These findings offer both a robust theoretical pillar and a practical toolkit for high-precision CO2 accounting, ultimately safeguarding the economic integrity of carbon trading within CCUS-EOR initiatives.
Yu, Haobo, Hua, Chenquan, Yu, Wenxin, Zhao, Zerun
An Effective Pathway for Off-Road Tier 5 Emission Compliance03-19-08-00418/31/2026
Proposed Tier 5 off-highway emission regulations for the 19–56 kW engine class pose significant technical and economic challenges. Unlike larger platforms, where selective catalytic reduction (SCR) is the standard nitrogen oxide (NOX) control strategy, engines in this class face cost and packaging constraints that limit complex aftertreatment adoption. This article investigates whether a production Tier 4 diesel engine and its existing aftertreatment can meet proposed Tier 5 limits through calibration and minor hardware changes alone, without major redesign or SCR. The approach combined a cooled exhaust gas recirculation (EGR) strategy with start of injection (SOI) timing optimization to manage the NOX–particulate matter (PM) trade-off, using the stock diesel oxidation catalyst (DOC) and diesel particulate filter (DPF) system for particulate control. An EGR/SOI design-of-experiments (DOE) sweep identified an optimal calibration, validated over both the ramped modal cycle (RMC) and non-road transient cycle (NRTC) per Title 13 California Code of Regulations (CCR) Section 2423 for certification of variable-speed engines in this power category. Results indicate that the system can be a viable pathway of meeting upcoming Tier 5 final emission standards.
Patil, Shubham Vishwanath, Michlberger, Alexander, Bachu, Pruthvi R., Amaral Garcia, Herbert, Smith, Edward M.
Vinylene-Linked Covalent Organic Frameworks as Superior Photocatalysts for Hydrogen Evolution over Imine-Linked Counterparts2026-99-04148/28/2026
The scheme of photocatalysis of water, a way of hydrogen generation as a clean, high-efficiency fuel source for aircraft and long-range transport systems has received considerable interest. The development of the covalent organic framework (COF) - derived materials for hydrogen evolution reaction (HER) has since become a research highlight. Compared to traditional methods, photocatalytic hydrogen evolution systems based on COFs can provide ways of generating hydrogen gas without depending upon noble metal catalysts, thereby enhancing the sustainability and prospects of this technology for future aerospace energy applications.In this work, two covalent organic frameworks (COFs) with distinct linkages—a vinylene-linked COF A (via Knoevenagel condensation) and an imine-linked COF B (via Schiff-base reaction)—were designed and synthesized to compare their performance in the photocatalystic hydrogen evolution reaction (HER). Structural and electrochemical characterizations confirmed that, despite lower crystallinity and specific surface area due to pore blockage, COF A exhibited a suitable band structure for photocatalysis and achieved an HER rate of 56 μmol h^–1 g^–1 under simulated sunlight. In contrast, COF B was ineffective. This study experimentally validates the superior photocatalytic potential of vinylene-linked COFs over imine-linked counterparts for HER, highlighting their potential as non-noble-metal catalysts for aerospace and transport-oriented fuel generation.
Cao, Yijie, Luo, Xin
Study of Port Fuel Injection Engine Cold Start Unburned Hydrocarbons Reduction Using Computational Fluid Dynamics with a Reduced Iso-Octane Mechanism Considering Various Isomers and Thermal Decompositions03-19-04-00218/27/2026
A modeling study was performed to find solutions to reduce the unburned hydrocarbons during cold start of a PFI (port fuel injection) SI (spark ignition) engine. Through modeling, the root cause for the high unburned hydrocarbons of the baseline engine during cold start was found. The slow combustion, which is due to the high amount of exhaust gas flowing back into the intake port and then becoming trapped inside the cylinder, is the root cause. A new valve lift, which can reduce the internal residual by 26%, was designed. Along with a fuel amount decrease of 35%, the UHC (unburned hydrocarbons) before the three-way catalyst can be reduced by 40%. The exhaust temperature using the new valve lift design increases by 400°C, which improves the performance of the three-way catalyst for further reducing UHC. In addition to the adoption of the new valve lift, an active SAI (secondary air injection) strategy was also investigated. Modeling results show that SAI can promote secondary combustion in the exhaust pipes to increase exhaust temperature and thus is beneficial for further oxidizing unburned hydrocarbons. The amount of active SAI mass flow rate should be controlled to less than 25% of the intake air flow rate to avoid the cooling effect dominating over the oxidation process. The duration of SAI should be from EVO (exhaust valve opening) to IVO (intake valve opening). For combustion modeling, a newly reduced iso-octane chemical kinetic mechanism was developed using carbon flux analysis to extract major reaction pathways for a wide range of practical engine temperature conditions. In the new reduced mechanism, a skeletal sub-mechanism for species starting from iso-octane to C4 is coupled with a recently updated H2/O2/CO/C1–C4 detailed sub-mechanism. Including a reduced NOx (oxides of nitrogen) sub-mechanism, the final mechanism has 681 species and 3332 reactions. Before the new reduced iso-octane mechanism was used, it had been validated with available experimental data of ignition delay times, laminar flame speeds, and important species profiles in the literature. Both the investigation of PFI engine unburned hydrocarbons reduction under cold start operating conditions and the development of a reduced chemical mechanism are the objectives of this work.
Guo, Dongshao, Zhang, Licheng, Yang, Shiyou, Bourg, Cyrus, Sun, Yong, Abidin, Zainal, Lin, Shujun
Performance and Emission Control Enhancement Using Green-Synthesized Additives in Diesel Engine03-19-04-00208/24/2026
Cashew nut shell oil–based biodiesel (BD) is an environmentally friendly and sustainable alternative energy source that can help decrease the depletion of fossil fuels and reduce environmental pollution. In this research, the BD extracted from cashew nut shell was enriched with green-synthesized nanoparticles with various blends and evaluated for its performance. The BD20A blend recorded the best thermal efficiency of the brake, 29.5%, which was a boost of about 20.4% over diesel when using a medium load of 2.7 kW. Furthermore, the decrease in brake-specific fuel consumption was 36.2%, and exhaust gas temperature improved by 26.1% due to enhanced combustion, indicating better combustion and utilization of heat. The BD10A and BD20A recorded a considerable decrease in emissions compared to diesel under full-load conditions, with carbon monoxide and hydrocarbons reducing by 35.7% and 33.3%, respectively, and a moderate increase of nitrogen oxides. Among the multi-objective optimization approaches, the Jaya algorithm exhibited the fastest convergence rate and identified the optimum operating condition that achieved the best trade-off between engine performance and exhaust emissions. BD blends, particularly BD20A, provide greater thermal performance and better combustion behavior as well as lower exhaust emissions, making them viable as green alternatives to the traditional diesel fuel.
Victor Soosai Irudayaraj, S., Thanigaivelan, V., Brucely, Y., Lenin, N.
SAE Truck & Off-Highway Engineering: August 202626TOFHP088/13/2026
Engineering for uptime: A blueprint for commercial vehicle transformation KPIT experts address challenges of maintaining legacy architectures while introducing centralized compute, OTA, new energy platforms and AI layers - driving integration complexity and validation effort. Renewing the debate on diesel Alternatives State and federal legislation has helped double the consumption of renewable and biodiesel in North America over the past half decade. But is policy alone enough to make them ready for prime time? Q&A with Volvo's powertrain chief Mehdi Ferhan said optimizing existing technology was a challenge but ultimately the right solution for Volvo to satisfy new NOx regulations. And he says he has never been bored a single day in his career as an engineer. Editorial Needed: Engineers "at the intersections" Electrification at the edge: Engineering for the reality of off-highway environments Why your bearing isn't enough: A guide to designing a maintenance-free pivot Axial flux motors evolve hybrid design for heavy-duty trucks Rivian's Scaringe says R2 will help pay huge R&D costs Wirtgen demos digital technologies in roadbuilding workflow Product Briefs SPOTLIGHTS: Power Generation & Gensets; Fasteners/Adhesives Q&A FPT says commercial powertrain tech must diversify to meet modern demands
Experimental Study on the Combined Effects of Swirl and Inlet Offset on the Flow through an Automotive Catalyst Monolith Substrate03-19-04-00198/7/2026
Maldistributed flow within an automotive catalyst can cause reduced conversion efficiency, high pressure loss, and premature deactivation. However, packaging constraints often result in uneven flow distribution between the monolith channels, thus compromising design and, inevitably, performance of the device. Flow uniformity may be improved by the introduction of swirl upstream of the catalyst assembly, and in turbocharged applications the residual swirl from the turbine can serve that purpose. Indeed, low swirl has been shown to provide favorable flow uniformity in the monolith substrate in an axisymmetric flow setup. However, the automotive exhaust aftertreatment setups are seldom axisymmetric, and the combined effects of inlet swirl and offset on the flow profile through a monolith substrate are unknown. To address this gap, this study provides the first systematic experimental characterization of the coupled influence of inlet swirl and packaging-relevant inlet offset on flow development and uniformity in a sudden expansion catalyst assembly. Particle image velocimetry (PIV), wall pressure measurements, and hot-wire anemometry (HWA) are combined to link the upstream separation and recirculation structures to the velocity distribution downstream of the monolith. The results reveal a previously unreported swirl-dependent sensitivity to geometric asymmetry: under no-swirl and moderate-swirl conditions, flow uniformity is robust to inlet offset, varying by no more than 1.4%, whereas at low swirl the offset reduces uniformity by up to 8% at high mass flow rate. Increasing mass flow rate reduces uniformity by up to 15%, while swirl improves uniformity by up to 19% relative to axial flow. These findings demonstrate that improvements observed for swirl in axisymmetric assemblies cannot be assumed to transfer directly to offset geometries. Swirl intensity and inlet alignment must instead be considered as coupled design variables. The measurements also provide a benchmark dataset for validating computational fluid dynamics simulations before their application to production-type systems.
Rusli, Ijhar, Aleksandrova, Svetlana, Medina, Humberto, Benjamin, Stephen F.
Q&A with Volvo's Powertrain chief26TOFHP08_038/1/2026
Mehdi Ferhan said optimizing existing technology was a challenge but ultimately the right solution for Volvo to satisfy new NOx regulations. And he says he has never been bored a single day in his career as an engineer. SAE Media senior editor Chris Clonts had an exclusive opportunity at ACT 2026 to sit down with Volvo Group's senior vice president of powertrain technology, Mehdi Ferhan. The talk of the day was EPA 2027 and its new NOx emission standard. Other topics in the free-ranging conversation included BEVs, hydrogen and current opportunities for engineers. The following was edited for length and clarity.
Clonts, Chris
Assessing the Water Resource Impacts of Carbon Conversion TechnologiesTBMG-555388/1/2026
In the race to combat climate change, scientists are developing technologies to turn carbon dioxide (CO2) into valuable fuels and chemicals. These innovations help curb greenhouse gases while providing a low-carbon fuel to power our future. As the U.S. shifts to a low-carbon economy, we need environmentally friendly fuels to power vehicles that are hard to electrify, like planes, ships and trains. Scientists are developing the technology to convert CO2 to fuel. However, this conversion requires a lot of energy and water.
Identification and Quantification of PAHs in Gasoline Soot Using ASE-GC-MS/MS2026-99-01107/31/2026
In the present work, a novel method that combines accelerated solvent extraction (ASE) and gas chromatography coupled with triple quadrupole tandem mass spectrometry (GC-MS/MS) was proposed to identify and quantify polycyclic aromatic hydrocarbons (PAHs) in gasoline soot. The n-hexane was employed to extract the target analytes, and the optimal extraction conditions were identified (cycle times = 3, extraction time = 30 min, extraction temperature = 120°C, and extraction pressure = 100 MPa). The extraction efficiency of six analytes was measured to assess the ASE method; the formation mechanism of partial PAHs was discussed, and the 18 PAHs in gasoline soot were studied both qualitatively and quantitatively under the optimal conditions. It was found that our new method reached a high correlation coefficient (between 0.9987 and 0.9997); the limits of quantification (LOQs) (S/N = 6) for these PAHs were between 0.003 and 0.009 ng/mL with a relative standard deviation (RSD) of 2.9–10.6%. Our method demonstrated good performance in determining the target analytes in soot samples, such as gasoline soot, some materials soot, co-combustion soot, gasoline, and materials. The PAHs differences in soot samples containing gasoline and materials soot samples were significant enough to obtain the observed discrimination. The method is an accurate and sensitive quantitative method to identify gasoline residues in soot samples of arson fire.
Liu, Shujun, Cao, Henan, Qi, Lijie, Liu, Yang, Li, Qi
Study on the Properties of Waterborne Polyurethane Laminating Adhesives2026-99-02117/31/2026
This paper designs and synthesizes a series of high-performance waterborne polyurethane (WPU) laminating adhesives using polyester, polyether polyols and isophorone diisocyanate as the main raw materials. It focuses on exploring the effects of polyol types and R value (the ratio of polyol to isocyanate) on the properties of the adhesives, including emulsion viscosity, solid content, water absorption rate of the adhesive film, mechanical properties, and bonding performance on different substrates. The results show that WPU2 with polycarbonate diol (PCDL) as the polyol has the best water resistance and the highest tensile strength; WPU1 with polytetrahydrofuran (PTMG) as the polyol has the optimal elongation at break and exhibits outstanding bonding performance on the polar substrate PET; the regulation of R value can optimize the bonding performance of the adhesive on the non-polar substrate BOPP. This type of WPU laminating adhesive features low VOC emissions, no benzene-based solvents, excellent flexibility, and good resistance to high and low temperatures. It not only meets the environmental protection and safety requirements in packaging fields such as food and medicine, but also shows potential application value in high-end fields like aerospace interior compounding and lightweight transportation structure bonding. Its performance is highly compatible with the strict requirements for materials in the modern aerospace and transportation industries. The adjustable strong adhesiveness, compliance with strict emission standards, and adaptability to various substrates make it an ideal choice for a new generation of composite manufacturing, especially suitable for industrial fields pursuing reliability, sustainability and high performance.
Wang, Chengming, Yu, Jiacheng, Wang, Huixia, Huang, Yiqiang, Ren, Xiue
Maximizing Autonomy, Minimizing Environmental Impact: The Cooperative Regenerative Braking2026-36-03167/30/2026
In conventional braking systems, the kinetic energy of a vehicle is predominantly converted into heat through friction, a thermodynamically inefficient process. This not only causes progressive wear of components but also leads to the release of various materials, including heavy metals and organic compounds. With increasing concern over non-exhaust emissions, the search for innovative solutions becomes imperative. In electrified vehicles (xEVs), regenerative braking emerges as a strategic technology, converting kinetic energy into electrical energy to recharge the battery and extend range. This process not only enhances the vehicle's energy efficiency but also results in reduced frequency and intensity of mechanical brake usage. Consequently, there is a direct reduction in the wear of friction braking components, which translates into a significant mitigation of particulate matter emissions associated with this wear. The optimization of these systems occurs through Cooperative Regenerative Braking (CRB), which intelligently integrates with hydraulic braking. The primary challenge lies in managing the transition between modes to recover maximum energy without compromising safety and driver comfort. This technical paper explores how CRB employs 'torque blending' via advanced ECUs and software to adjust in real-time the proportion of each braking type, aiming for maximum energy recovery in diverse driving scenarios. To verify the effectiveness of this system, practical tests were conducted on a vehicle. The results obtained from these tests were conclusive, demonstrating significant gains in energy efficiency, with an increased battery recharging capacity during decelerations, optimized by the braking system. This improvement in efficiency directly impacts the reduction in the use of the conventional friction brake system and, consequently, a sharp decrease in particulate matter emissions. In this context, the intelligent and cooperative management of regenerative braking is a strategic and fundamental component for building a more sustainable future in vehicular mobility.
Batagini, Emerson, Romão, Bruno
Influence of Aero Enablers on Brake Cooling Performance2026-36-03177/30/2026
Amid growing society concerns about environmental sustainability, fuel consumption has become a key factor in mitigating greenhouse gas emissions. As a result, modern vehicle design increasingly prioritizes aerodynamic drag reduction. However, aerodynamic enhancements can significantly affect brake cooling, since airflow distribution plays a crucial role in braking performance. This study explores the interplay between underbody aerodynamic features and brake cooling efficiency in production vehicles. Three body styles—compact sedan, midsize SUV, and minivan—were evaluated to determine how varying aerodynamic configurations influence airflow around the wheel assemblies. The findings highlight critical trade-offs between aerodynamic optimization and thermal management, offering valuable insights for achieving balanced vehicle development strategies.
Batista, Lorena, Motta, Daniel, Seren, Ericson, Bergel, André, Sarmento, Alisson, Terra, Rafael
Effects of Equivalence Ratio on Hydrogen Combustion Flow and NOX Emission Characteristics in a Jet-Trapped Vortex Combustor2026-99-08067/30/2026
The jet-trapped vortex combustor presented in this study was designed based on the trapped vortex combustor with good flame stability by introducing a jet flame-stabilization method. Leveraging the superior air-fuel mixing efficiency and enhanced heat and mass transfer of the jet stabilization method, this configuration addresses the inherent limitations of heat and mass transfer between the mainstream flow and the cavity in a conventional trapped vortex combustor. To investigate the influence of different hydrogen-air equivalence ratios on the flow dynamics, combustion performance, and emission within the jet-trapped vortex combustor, numerical simulations were conducted in this study. The results show that under different equivalence ratios, a vortex pair structure can be formed in the mixing zone between the hydrogen jet and the air jet. Complete combustion can be achieved at all equivalence ratios except for Φ = 1.56. When Φ is below 0.86, the axial distance required to achieve complete combustion progressively decreases as the equivalence ratio is reduced. The temperature distribution in the combustor is more uniform with minimal variation, and the concentration of NO emissions decreases progressively. Among these cases, the combustion efficiency, temperature distribution, and NO emission characteristic of the combustor are relatively better at Φ = 0.34.
Yan, Pinghua, Hou, Xinglong, Ren, Guanlong, Sun, Haijun, Luo, Kun, Yang, Shucheng
An Updated Data-Driven Greenhouse Gas Emission Rate Analysis for Vehicle Comparisons Applied to Europe14-15-03-00167/25/2026
This study presents a data-driven lifecycle assessment (LCA) framework for evaluating greenhouse gas (GHG) emissions from passenger vehicles across European electricity systems. The analysis compares battery electric vehicles (BEVs), full hybrid electric vehicles (FHEVs), and internal combustion engine vehicles (ICEVs) using both conventional average electricity emissions factors and time-resolved marginal emissions, referred to as real charging emissions (RCE). Hourly generation and interconnector/cross-border flow data for 2023 from 29 European countries are processed to estimate consumption-based marginal emissions rates that account for grid dispatch behavior and cross-border electricity flows. The approach is applied to two vehicles where multiple powertrains are available on the same platform, the 2024 Hyundai Kona (available as a BEV, FHEV, and ICEV) and Peugeot 2008 (available as a BEV and ICEV), to isolate drivetrain-related lifecycle differences. Results show substantial divergence between average and marginal emissions estimates, with a mean absolute difference in BEV–FHEV lifecycle emissions of 31–36 g CO2 eq/km across Europe. In several countries with carbon-intensive marginal generation, including Poland and Cyprus, BEVs may exhibit higher lifecycle emissions than comparable hybrids, while low-carbon grids such as Norway, Sweden, and France provide large BEV advantages. Sensitivity analyses demonstrate the importance of transmission losses, temperature effects, electricity imports, and charging timing. These findings highlight the limitations of average grid emissions factors in vehicle LCAs and underscore the importance of geographically and temporally resolved data-driven electricity emissions when assessing electrified vehicle climate impacts.
Drew, Alfred, Burton, Tristan, Senecal, Kelly, Davy, Martin, Leach, Felix
Energy-saving and Economic Evaluation of Vacuum Insulation Panels with Glass Wool Core-polyimide Membrane Structure in Hotel Buildings under Different Climatic Conditions2026-99-16527/24/2026
This study prepares high-performance PI/VIP composite thermal insulation materials for buildings by integrating polyimide (PI) composite membranes and vacuum insulation panels (VIPs), and uses EnergyPlus to explore their impacts on building energy conservation, operating costs, and carbon emissions under different climates. Experimental results show the materials have low thermal conductivity, long service life, and excellent thermal insulation and flame-retardant properties due to their internal vacuum structure inhibiting heat transfer. Simulations in Jinan (tropical monsoon), Heilongjiang (cold temperate), and Shenzhen (subtropical humid) climates indicate that compared with traditional XPS and rock wool boards, buildings using PI/VIP composites achieve 21.3%, 34.7%, and 18.9% higher annual energy-saving efficiency respectively, with 27%-41% lower carbon emissions; the most significant effects in Heilongjiang highlight the material’s great promotion potential in severe cold areas.
Bian, Chenqian, Chen, Zhaofeng
Study on the Removal of Volatile Organic Compounds in Water by Ultracrosslinked Network Hydrogels2026-99-16427/24/2026
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Chen, Ruini, Lu, Bing
Experimental Investigation on Unburned Methanol and Formaldehyde Emissions from a Direct-Injection Diesel / Methanol Dual-Fuel Engine2026-99-16467/24/2026
For large-bore marine methanol / diesel dual-fuel engines, this study investigates the formation characteristics of unregulated emissions through experimental methods and explores the mechanisms by which engine load and injection timing influence the emissions of unburned methanol and formaldehyde. The study was carried out on a supercharged intercooled inline six-cylinder engine, and Fourier Transform Infrared Spectroscopy (FTIR) was used to monitor the exhaust composition in real time. The study shows that methanol released in the exhaust is due to the incomplete combustion of the methanol fuel. In the combustion process of methanol fuel, formaldehyde mainly arises from two pathways, the first of which is the partial oxidation of methanol inside the cylinder; secondly, the unburned methanol in the exhaust gas oxidizes in the exhaust pipe to generate formaldehyde. As the load increased from 25% to 100%, the unburned methanol emissions decreased by 29%, and formaldehyde emissions decreased by 71%. This is mainly attributed to the enhanced oxidation reaction and reduced wall crevice effect due to the increased combustion temperature. Methanol injection timing optimization was effective in controlling unregulated emissions, with methanol emissions lower at -7° CA ATDC and formaldehyde emissions reaching larger values under this condition. Delaying the diesel injection to -16°CA ATDC led to a 38% increase in unburned methanol emissions, caused by fuel spray interactions and longer stagnation, whereas formaldehyde emissions showed minimal change.
Jiang, Yuqi, Li, Hongmei, Zhang, Wenzheng, Li, Xiao, Zheng, Liang, Meng, Yangqian, Gu, Xianan, Hua, Hanqing
NOx Tracking Parameter AccuracyJ3349_202607 (Current)7/23/2026
This SAE Information Report provides SAE’s recommendations for meeting the requirements for Real Emissions Assessment Logging (REAL) oxides of nitrogen (NOx) accuracy demonstration and for the implementation of REAL NOx binning requirements as defined in onboard diagnostics (OBD) regulations 13 CCR 1971.1 and 13 CCR 1968.2.
Vehicle E E System Diagnostic Standards Committee
Research on Urban Bus Timetable Optimization Based on Deep Reinforcement Learning2026-99-05387/10/2026
Public transportation serves as a crucial component of urban mobility, contributing to the alleviation of urban congestion, reduction of travel expenses, and mitigation of air pollution. Nonetheless, the dynamic passenger demand and the complex traffic conditions render traditional bus timetables inadequate, leading to ineffective allocation of public transportation resources. Consequently, it is essential to create bus timetables that are responsive to actual traffic scenarios and fluctuating passenger demand. This study regards the bus timetable planning problem as a Markov decision-making process within a discrete time framework, proposing a deep reinforcement learning-based optimization model for bus timetables. In particular, the model is designed to account for both bus companies and passengers, incorporating a state space and reward calculation method that emphasizes passenger comfort. Then Deep Q-Network (DQN) methodology is employed to issue instructions on whether a bus departure at each time, and bus timetable is generated gradually over time. Experimental results indicate that the proposed approach significantly reduces bus travel costs and enhances the overall travel experience for passengers in comparison to traditional methods.
Xu, Jie, Xia, Dong, Yang, Jianxi, Wang, Bing
Sustainable Airport Emissions Reduction through Optimized End-Around Taxiway Operations: A Simulation Approach2026-99-05827/10/2026
To mitigate the risks of runway incursions during aircraft transitions between closely spaced parallel runways, major hub airports globally have implemented End-Around Taxiway (EAT) as an effective safety solution. Operational data from leading international airports confirms that EAT installations have successfully enhanced surface safety while maintaining operational efficiency. However, the EAT involves a longer taxiing route, resulting in higher fuel consumption and pollutant emissions. This study takes the example of a set of closely spaced parallel runways at a domestic airport to analyze the ground taxiing process of arrival and departure flights, proposing a dynamic allocation strategy for EAT operations that can achieve energy conservation and emission reduction during the taxiing process. Through simulation, its effective operational performance is studied.
Wang, Zinan, Ye, Bojia
Study on Diesel-Methanol Non-Premixed Combustion Characteristics of a Marine Dual-Fuel Engine at Different Methanol Substitution Rate2026-99-05177/10/2026
Methanol use in marine engines has the potential to reduce nitrogen oxide emissions, particulates, and greenhouse gas emissions. A turbocharged four-stroke marine diesel powerplant was converted to run as a double-DI (direct injection) diesel-methanol hybrid engine. Experimental studies using a non-premixed combustion scheme showed that higher methanol substitution ratios (MSR) led to increased peak heat release rates. The combustion process displayed distinctive two-phase behaviors. Increasing MSR caused retarded ignition timing, shortened combustion duration, and improved thermal efficiency. Combustion stability was significantly improved at higher MSR. Emissions results showed NOX and HC were increased in proportion to MSR, whilst particulate emissions and CO concentrations were inversely reduced. Methanol enrichment was found to enhance NOX and HC formation processes but also accelerate soot particulate decomposition and CO oxidation mechanisms.
Li, Xiao, Jiang, Yuqi, Yan, Ping, Zheng, Liang, Li, Hongmei, Zhang, Wenzheng, Chen, Chao, Man, Zhongguo
NO x Formation Characteristics of Lean Hydrogen Combustion: From 0D Analysis to Comprehensive 3D-CFD Engine Investigations2026-01-07327/1/2026
The transition toward climate-neutral transportation requires powertrain concepts that combine high efficiency with low pollutant emissions. In this context, hydrogen-fueled internal combustion engines represent a promising solution when hydrogen is produced from renewable energy sources. Owing to its specific molecular properties, hydrogen offers new possibilities for influencing and optimizing the combustion process and reducing the emission formation. This paper presents a numerical approach for characterizing the NOx formation in a single-cylinder research engine equipped with port fuel injection and a passive pre-chamber ignition system. The single-cylinder is operated over a wide range of engine loads and speeds, covering air-to-fuel ratios from λ=1.5 to 2.5 and achieving up to 23 bar indicated mean effective pressure. The study focuses on the influence of engine load and mixture composition on NOx emissions. A dedicated look-up table approach in combination with several reaction parameters based on the extended Zeldovich mechanism are evaluated through comparison with experimental data. Furthermore, multiple sampling positions within the CFD mesh are examined. The simulations reproduce measured trends across variations in load and air-to-fuel ratio with good accuracy. At high load and λ=1.5, NOx emissions of up to 6000 ppm are produced, decreasing exponentially with increasing excess air. Finally, potential NOx reduction strategies for the single-cylinder are examined. While influencing the mixture homogenization shows limited effectiveness, temperature-based actions prove to be more effective. Among the investigated approaches, a Miller intake valve strategy yields the largest benefit, achieving approximately 10% NOx reduction by lowering end-of-compression temperatures and increasing residual gas dilution under otherwise identical operating conditions.
Gal, Thomas, Vacca, Antonino, Chiodi, Marco, Schmelcher, Robin, Kulzer, Andre Casal
Experimental Study of Warm-Up And Startability Operations in a Spark Ignition Engine Fueled with Ethanol Gasoline Blends2026-01-07387/1/2026
The mitigation of Greenhouse Gas (GHG) emissions poses a major challenge for the transportation sector, driving the need for renewable fuels. Bioethanol represents a promising fuel for Spark-Ignition (SI) engines, combining a reduced life-cycle CO₂ impact with advantageous combustion properties. However, despite its proven performance under steady-state conditions, the widespread of fuels with high ethanol content is still constrained by significant difficulties during engine cold-start operation. This study aims to experimentally assess the effect of ethanol concentration on cold-start performance and warm-up transient behavior of a Naturally Aspirated (NA), Port Fuel Injected (PFI) SI engine. Warm-up tests were conducted at an operating condition of 2000 rpm engine speed and 20 Nm torque using three fuels with increasing ethanol content: commercial gasoline (E5), E30 and E60. In addition, dedicated startability tests were carried out for E60 and neat ethanol (E100) at different initial engine wall temperatures to evaluate fuel sensitivity to thermal conditions during engine start. The experimental results indicate that increasing ethanol concentration has a negligible effect on the overall duration of the warm-up process, while leading to a modest reduction in both engine wall and exhaust gas temperatures. At the same time, E100 displays severe startability limitations at low initial wall temperatures, requiring repeated cranking attempts before stable operation can be achieved. The same startability issues have been observed for E60 but with limited intensity. Two minimum engine wall temperature ranges were identified for reliable cold-start operation at 20-25 °C for E60 and 25-30°C for E100. Overall, these findings experimentally confirm the dominant influence of engine thermal conditions on the reliable startability of ethanol-fueled spark-ignition engines.
Falbo, Luigi, Falbo, Biagio, Perrone, Diego, Castiglione, Teresa
Biofuel Effect on Regeneration Capability and Soot Reactivity in SCRoF Systems2026-01-07507/1/2026
Biodiesel blends (B7, B20, B100) were evaluated in a Stage V-compliant SCR on Filter (SCRoF) system for heavy-duty applications to quantify soot reactivity and filter regeneration capability. Compared to conventional diesel (B7), B20 showed slightly faster regeneration performance under real-driving conditions, while B100 resulted in reduced particulate formation and higher soot reactivity, with more intense exothermic events requiring careful management. These differences are attributed to the distinct physical-chemical properties of the fuels (oxygen content, lower heating value) and their interaction with Diesel Oxidation Catalyst (DOC)/SCRoF. All tests were conducted on an engine dynamometer with a Cursor 9 FPT (Fiat Powertrain). Findings are discussed in the context of EU Stage V limits and practical control strategies for heavy-duty applications.
Costa, Simone
Improved Thermal Management for Operating a Battery Electric City Bus under Real Driving Conditions2026-01-07587/1/2026
The goal of reducing global CO2 emissions requires actions especially for the transportation sector. To achieve the goal, electric traction motors are frequently implemented in passenger vehicles, as well as in commercial vehicles like heavy-duty trucks or buses. Particularly electric city buses have the potential to reduce the local emissions in urban areas and provide local exhaust-emission-free mobility. While their number of registrations rises, research focusses on the improvement of the overall system in order to increase energy efficiency. High importance is gained by the thermal management of the whole system. This research investigates a simulative approach to improve the thermal management and therefore the energy efficiency of an electric city bus. The different thermal components of an electric city bus like drive system, battery system and heating, ventilation and air conditioning system (HVAC system) are modelled. Their thermal behavior has been validated in previous research. Based on the validated model, this study proposes an improved thermal management that, state-dependent, combines the thermal circuits of the single components to reduce the overall energy demand. Cooling or heating is provided by the HVAC system. Furthermore, the simulation utilizes real driving cycles of a city bus in the Hamburg area. Measurement data from an entire year are examined by a cluster analysis that results in typical application profiles for urban bus traffic. These profiles are used as basis for further research. An operating strategy for the thermal management of an electric city bus under real driving conditions is developed using the simulation model. Results are presented, which show that the overall energy demand decreases due to an improved, application profile-dependent thermal management system.
Schäfer, Henrik, Hellberg, Tobias, Meywerk, Martin
Numerical Analysis of Directly Injected Hydrogen into a High-Pressure Chamber2026-01-07457/1/2026
Hydrogen Internal Combustion Engines have emerged as an option for decarbonizing heavy-duty transportation. However, injecting high-pressure hydrogen gas into pressurized combustion chambers induces complex compressible flow phenomena, including choked flow and under-expanded supersonic jet structures, which challenge conventional modeling approaches for optimizing engine performance and emissions. This study conducts a numerical investigation of transient hydrogen injection into a high-pressure argon environment, benchmarking a 2D axisymmetric Computational Fluid Dynamics (CFD) model against high-fidelity experimental optical measurements. Utilizing Ansys Fluent with a density-based solver, coupled with the k-ω SST turbulence model and species transport equations, simulations were performed at injection pressures of 6 MPa and 10 MPa into a 1 MPa ambient chamber. The simulation successfully captured fundamental compressible physics, including Mach disk formation and significant expansion cooling near the nozzle exit. Validation results revealed a strong dependency on the nozzle pressure ratio (nPR). At 6 MPa (nPR=6), the model achieved good agreement with experimental data, predicting tip penetration depth within 10% . However, at 10 MPa (nPR=10), while axial penetration depth predictions remained within the 10% error margin, they were consistently underestimated, and radial dispersion was significantly under-predicted. These discrepancies at high energy levels highlight the challenges of predicting turbulent entrainment within the current modeling framework. The results suggests that the observed deviations are likely to be caused by combined limitations related to the RANS turbulence model, the potential shortcomings of the 2D axisymmetric assumption in resolving highly transient mixing phenomena, the meshing strategy used, the constant assumption made about the coefficient of discharge, and the crucial role of the Turbulent Schmidt number (SCt).
Castilla Batun, Uriel Isaac, Alzahrani, Fahad
Experimental Investigation of Fuel Cutout Strategies in a Heavy-Duty Gasoline Compression Ignition Engine03-19-03-00156/26/2026
This study investigates Gasoline Compression Ignition (GCI), a family of advanced combustion strategies that can be used to achieve low engine-out criteria pollutant emissions in the heavy-duty transportation sector. In particular, high fuel stratification GCI (HFS-GCI) has been shown to have high thermal efficiencies while maintaining a highly controllable and responsive mixing-controlled combustion event. However, stable combustion at low loads has been shown to be the principal challenge to the implementation of HFS-GCI in production applications. It has also been observed that several strategies that achieve stable combustion at low loads result either in increased emissions or efficiency penalties. While the achievement and maintenance of high enough exhaust temperatures for efficient aftertreatment operation is a significant challenge at low loads even for traditional diesel engine operation, this challenge is exacerbated by the low reactivity and colder flame temperature of gasoline. In recent single-cylinder and 1D simulation studies, fuel cutout strategies have been proposed as an enabling strategy to simultaneously improve combustion stability at low loads and increase exhaust temperatures. In this study, fuel cutout strategies are studied in a prototype multicylinder heavy-duty GCI engine based on a Cummins ISX15 diesel engine. Steady-state engine studies are conducted at warm and cold idle conditions to identify combinations of cylinders that provide the most benefit. NOx and soot limits are set and the performance of cutout strategies are compared to a pre-optimized baseline. The most optimal strategies from steady-state testing are then implemented under transient test cycle conditions similar to those required under United States regulatory testing. The strategies were found to offer simultaneous improvements in stability, fuel consumption, criteria pollutants, and turbine outlet temperature. The choice of cylinders whose fuel supply was cut was seen to be important in realizing the observed benefits. The use of fuel cutout strategies offered optimal performance at all the conditions considered, offering an additional lever to improve the performance of HFS-GCI and highlighting a promising pathway to the use of gasoline-like fuels as alternatives to diesel in heavy-duty engines.
Viswanathan, Aravindh Babu, Zhang, Yu, Merritt, Brock
Spray–Wall Interaction at Thermal Swing Coatings in SI Engines03-19-03-00146/25/2026
As a contribution to the reduction of greenhouse gas emissions in the transportation sector, the indicated efficiency of SI engines can be increased via thermal swing coatings. Thereby, a decrease in greenhouse gas emissions can be achieved, although not at all operating conditions. Here, the often-observed increased hydrocarbon emission partially overcompensates the reduced wall heat losses. The main root cause is always attributed to the increased surface roughness and porosity, leading to an increased crevice volume. Further investigations were performed at a single-cylinder engine equipped with a FTIR for species analysis of hydrocarbon emissions. A comparison of direct injection and port fuel injection were performed for RON95 E10 and methanol to assess the influence of mixture preparation. 3D CFD was used to additionally investigate the in-cylinder processes. The comparison of port fuel injection and direct injection showed a significant influence on the fuel hydrocarbon emissions for the direct injection when the thermal swing coating was applied. The effect is more pronounced for methanol. For port fuel injection nearly the same or reduced fuel hydrocarbon emissions can be observed. This is mainly attributed to an increased wall film agglomeration at the piston for the thermal swing coating in case of direct injection, which can be observed in 3D CFD. Due to the low thermal effusivity of the coating, the droplet impingement leads to a notable decrease in the surface temperature. This results in lower evaporation of the fuel and a longer droplet lifetime. Consequently, a fuel wall film is still present at top dead center after ignition leading to additional hydrocarbon emissions.
Fischer, Marcus, Pischinger, Stefan
Holistic Sound Package Design for Optimal NVH and Carbon Footprint of a BEV2026-01-07086/20/2026
Vehicle sound packages are usually designed to provide a given level of vehicle Noise, Vibration, and Harshness (NVH) comfort, within weight and cost constraints. Optimal comfort results can be obtained by considering the interaction of all the parts as a full physical system. So far, extensive research has already been performed and published on optimizing vehicle sound packages to achieve effective noise reduction at lowest cost and weight. Nowadays, due to the urgency of the transition to carbon neutrality, sound packages must also address the reduction of the full vehicle life cycle carbon emissions. Sound package components should use materials that have a low emission impact during production and that are suitable for recycling at the end of the vehicle’s life. This entails reconsidering the material solutions chosen for the sound package as a whole, rather than for each individual component. This article describes possible differentiations in the design of a sound package involving NVH, sustainability, and weight/cost requirements. The study examines how interior and exterior trim components were combined to achieve both optimal NVH and polymer rationalization, through the introduction of mono-material parts and focusing in particular on the use of a new polyester fiber-based floor decoupler, which achieves comparable NVH performance to polyurethane foam without affecting static compression. The article summarizes the vehicle-level performance related to NVH, sustainability, and weight for three sound packages prioritizing either NVH, sustainability or material cost, including a breakdown to analyze the contributions of various components to the overall outcome. A simple metric is introduced to evaluate sustainability, including material, production, use-phase and end-of-life related Greenhouse Gas (GHG) emissions [7–10]. The NVH evaluation involves measuring airborne transfer functions (ATF), complemented by indoor road noise tests. NVH improvements were achieved without an increase in weight, and weight reduction was also possible without negatively impacting NVH performance, both results enhancing the carbon footprint.
Courtois, Theophane, Cardillo, Marco, Criscione, Mattia, Gerges, Youssef, Massocco, Andrea
A Modeling and Experimental Study of the Argon Power Cycle Using Mixing-Controlled Combustion2026-01-50436/19/2026
The closed-cycle hydrogen-fueled argon power cycle is a zero emissions concept that combines a carbon-free fuel with argon as a diluent replacement for nitrogen. The lack of nitrogen in the argon power cycle results in zero NOx emissions on an internal combustion engine platform. There is also massive efficiency improvement because argon is monatomic and has a very high ratio of specific heats. However, this will also result in combustion temperatures and pressures exceeding those normally achieved on an air-standard engine platform. The literature shows conflict between modeling, which promises incredibly high efficiency gains, and experiment, which show more modest efficiency gains. This work combined thermodynamic modeling, literature analysis, and experiments to understand this discrepancy and ultimately understand what level of efficiency gain can be expected for the argon power cycle. It was found that while low compression ratio engines stand to see the largest relative efficiency improvement, high compression ratio engines are the ones that can ultimately achieve ~60%+ efficiency, corresponding to a 15–20% relative improvement in efficiency over an air-standard engine platform operating at or above 50% efficiency. The elevated temperatures and pressures of the cycle result in knock in spark ignition, so either a high compression ratio knock mitigation strategy or mixing-controlled operation is required. Experiments conducted using a diesel-fueled compression ignition engine showed that a 30% argon replacement resulted in ~6% and full nitrogen replacement with argon resulted in ~14% relative efficiency improvement at 8 bar gross indicated mean effective pressure (IMEPg) without intake boosting on a heavy-duty engine with a compression ratio of 20.0 and late intake valve closing, agreeing with modeling results. The key takeaway to match modeling and experimental trends is to accurately model heat transfer, which increases significantly for the argon power cycle.
Gainey, Brian, Ahrling, Christoffer, Tunestal, Per, Tuner, Martin
Accelerated Computational Fluid Dynamics (CFD)-Based Quantitative Prediction of Urea Deposition in Selective Catalytic Reduction (SCR) Systems2026-01-50416/12/2026
Mitigation of harmful emissions from oil-based engines is essential to avoid environmental pollution and comply with various NOx regulations across the globe. This can be partially achieved by injecting urea to produce ammonia (NH3), which reacts with NOx in a catalyst to produce harmless nitrogen (N2) and water vapor (H2O). However, urea deposition in a selective catalytic reduction (SCR) system poses a significant threat to the NOx removal process by not only reducing the urea conversion rate but also blocking the incoming flow and causing an additional pressure drop. Numerical modeling of this urea deposit formation involves multiphase flow physics coupled with accurate heat transfer calculations. Additionally, since urea decomposes into various by-products like biuret, cyanuric acid (CYA), and ammelide, detailed chemical kinetics modeling is equally important. Accurate and fast computational fluid dynamics (CFD) simulations can help accelerate SCR system design cycles, leading to a reduction in experimental cost. In this study, we employ CONVERGE CFD to model the whole process from urea–water solution (UWS) injection to droplet evaporation and decomposition (using 12-step detailed-chemistry), film formation, and final deposition as a solid. A new spray-wall interaction model is introduced based on published experimental observations. The efficacy of the numerical model is demonstrated using an S-bend tube, where the UWS is injected just at the end of the S-bend. The predicted deposit mass and patterns are compared with the experiments, and good agreement is observed for three different operating conditions. A novel boundary morphing feature is activated to model the deformation of the tube walls because of urea deposition. Finally, to accelerate the simulations, a spray database approach is introduced. Coupled with the fixed-flow feature, this results in around 58% reduction in computational time without compromising accuracy. The present work thus provides a numerical framework to accurately capture urea deposition with a fast turnaround time.
Morab, Sumant R., Khalate, Suraj, Ansari, Shoaib, Yang, Pengze
SAE Truck & Off-Highway Engineering: June 202626TOFHP066/11/2026
Hitting the road in the all-new VNR Volvo Trucks' revised VNR brings updated safety tech, improved fuel economy and driver comfort features to the regional haul segment. In fuel control How to ensure off-highway combustion systems operate with sufficient control to meet tightening emissions standards and evolving fuel landscapes without sacrificing reliability. Keeping industrial vehicles secure in a digital landscape OEMs, integrators and suppliers must continuously process, assess and identify platform vulnerabilities to prioritize and implement updates that protect systems from cyberattacks and data breaches. Editorial Diversification key for sustainable fleets ACT 2026: Uncertainty still exists over EPA 2027 NOx limit ZF bets big on hybrid transmissions Moog simplifies off-highway electrification Bosch shows off its first U.S. electrolyzer Microvision fast-tracks adoption of Luminar tech; eyes defense, industrial sectors Future-ready, customizable connectivity powers precision agriculture Kenworth's new C580 clocks in for work Harbinger extends its range of medium-duty EVs Kubota's SVL110-3 brings new tech and service features to CTL segment Product Briefs SPOTLIGHTS: Diesel Engines & Subsystems; Manufacturing Tools & Materials; Motors, Inverters & Gearboxes Q&A Volvo turns attention to vocational trucks
Potential of ORC-Based Waste Heat Recovery in Conventional and Hybrid Heavy-Duty Powertrains2026-37-00186/9/2026
Heavy-duty vehicles significantly contribute to greenhouse gas emissions and urban air pollution, especially during cold-starts and transients when engine and aftertreatment efficiencies drop. Waste heat recovery (WHR) via Organic Rankine Cycle (ORC) systems offers a practical solution to improve fuel efficiency and cut CO₂ in real-world heavy-duty operations. This study examines ORC-based WHR integration into conventional and hybrid powertrains of an Isuzu FTR850 truck, analyzing four configurations: Shell-and-Tube or Plate heat exchangers with simple or regenerative ORC layouts. For hybrids, it compares two engine sizes and energy management strategies: an optimized fuzzy logic approach versus constant-power operation to enhance exhaust heat recovery. A validated quasi-static simulation framework is used to predict fuel consumption and exhaust properties over representative duty cycles. 2D performance maps using exhaust temperature and mass flow as inputs are used to model the WHR under off-design conditions. Results show that the recovery of waste heat WHR depends on the hybridization level and strategy. Conventional powertrains benefit most from Shell-and-Tube exchangers, recovering ~2 kWh of electrical energy per 8-hour cycle and reducing fuel consumption by 0.5%. Hybrid setups recover up to 3.9 kWh from exhaust gases with a simple layout coupled with a Shell-and-Tube heat exchanger under constant-power control. Electricity is used to support onboard auxiliaries and battery charging, further lowering fuel demand (-44%) and emissions. Finally, a multi-objective optimization was performed to exploit the synergy between hybridization and WHR while maintaining acceptable payload and battery operating conditions.
Donateo, Teresa, Morrone, Pietropaolo
CFD Modelling of an Asymmetric Hydrogen Injector Cap for Direct Injection Applications: Design Impact on Jets Structure and Momentum Flux2026-37-00116/9/2026
The adoption of hydrogen as a carbon-neutral sustainable fuel for internal combustion is regarded as a promising solution to reduce greenhouse gases and pollutant emissions. In this framework, the injection system plays a crucial role, being responsible for delivering a large amount of fuel to the combustion chamber. Currently, low-pressure direct injection is considered one of the best solutions to ensure the appropriate fuel delivery. The use of caps has proven particularly effective, as they enable a potentially unlimited range of geometries while minimizing modifications to the injector hardware. Experimental campaigns and computational fluid dynamics (CFD) simulations can be used together as complementary tools to speed up the development process and explore multiple combinations of parameters, thereby optimizing the overall design of both the engine and the caps. In the present paper, a single-hole GDI-derived hydrogen prototype injector equipped with a two-hole asymmetric cap and fed with hydrogen is analyzed through both experiments and CFD simulations under two different operating conditions in terms of rail pressure. Cap pressure, overall fuel instantaneous mass flow rate and hole-specific jet momentum have been measured during the experimental campaign. The resulting data were used as boundary conditions and as targets for the validation of steady-state CFD computations, where the same equipment has been simulated. In particular, the momentum flux produced by the two jets emerging from the forming cap was used to validate the numerical methodology against experimental outcomes. Moreover, the exact dimensions of cap holes have been taken by means of optical microscope and applied to the simulation to compare the real geometry against the nominal one. Therefore, the impact of the effective cap geometry is explored, evidencing a noticeable dependence specifically of the cap backpressure and therefore of the injection system performance on the details of the cap design.
Pavan, Nicolo, Breda, Sebastiano, Duni, Andrea, Martino, Manuel, Fontanesi, Stefano, Postrioti, Lucio
Combined EGR-Air Dilution Effects on Performance, Combustion and Emissions of a Single-Cylinder Spark-Ignition Direct-Injection Hydrogen Engine2026-37-00096/9/2026
Hydrogen internal combustion engines (H2ICE) have emerged as a promising solution for decarbonisation of the transport sector, due to low cost and potential for rapid deployment. However, abnormal combustion and high nitrogen oxide (NOx) emissions limit stoichiometric operation, making dilution strategies essential. While lean combustion has been widely studied, combined dilution strategies of air and exhaust gas recirculation (EGR) require further investigation. This work presents experimental results from a boosted 0.5-litre spark-ignition direct-injection single-cylinder research engine equipped with high-tumble ports and cooled high-pressure EGR. Relative air–fuel ratios (lambda) of 1 to 3 and EGR rates of 0 to 40% are evaluated at 5, 10, and 15 bar of indicated mean effective pressure (IMEP) at 2000 rpm to assess effects on net indicated thermal efficiency (nITE), combustion, and emissions. A peak nITE of 43.5% is achieved at 10 bar IMEP, λ = 2.5, and 30% EGR, which can be primarily attributed to low heat losses while maintaining lower combustion losses than at higher dilution levels. NOx emissions are effectively mitigated with increasing EGR and are largely independent of lambda at 5 bar IMEP under EGR dilution. At high load, EGR is shown to be beneficial to achieve high efficiency and lower NOx at lower dilution rates, thereby reducing boosting requirements. Equivalent dilution parameters are used to investigate combined effects of EGR and air dilution, from a mass dilution perspective with the mass dilution rate (MDR) and equivalent thermal reduction with the thermal dilution parameter (TDP). Indicated efficiency and unburned hydrogen emissions correlated strongly with MDR, while temperature-dependent parameters showed a high correlation with TDP. At constant engine speed, burn durations are shown to depend mainly on degree of thermal dilution, with no effect of load observed. At high dilution rates, combustion became increasingly insensitive to further dilution, indicating the presence of thermodiffusive instabilities under high levels of both EGR and air dilution.
King, Aidan, Islam, Reza, Pickering, Simon, Yuan, Hao, Mudge, Henry, Giles, Karl, Goyal, Harsh, Jones, Peter, Akehurst, Sam, Esposito, Stefania
Nitrogen-Based Emissions from Ammonia Combustion in a Heavy-Duty Spark Ignition Engine2026-37-00326/9/2026
Ammonia (NH3) is a carbon-free fuel with strong potential for spark-ignition (SI) engine applications. However, the engine can produce complex nitrogen-based emissions not adequately captured by conventional engine models. This study consolidated the results of experimental and numerical studies on the use of neat NH3 combustion in a heavy-duty compression-ignition engine converted to spark-ignition operation, first for a sweep of equivalence ratios (ϕ) from 0.7 to 1.0, and another from varying the energy substitution ratio of methane (CH4)– NH3 blends from neat CH4 to neat NH3 at constant ϕ = 0.8. Two 0-D two-zone SI engine models with detailed chemistry (called “original” and “extended”) predicted engine thermodynamics and emissions. While the original model reproduced in-cylinder pressure and combustion phasing, it failed to capture the effect of fuel composition or operating condition on NO trends, both under- and over-predicting them for neat NH3 and CH4-rich operations. An extension of the model incorporating a burned-zone batch reactor and two more reactors simulating the post-combustion oxidation of the mixture exiting crevices and the DeNOx processes during exhaust blowdown were implemented to address these limitations. Analysis of NO formation pathways highlighted the differences between modeling approaches. The equilibrium assumptions in the original model restricted NO formation primarily to thermal (Zeldovich) mechanisms. In contrast, the kinetics-driven model showed that non-thermal pathways dominate NO formation for all NH3-containing cases, which shows the limitations of conventional SI models developed for hydrocarbons when applied to nitrogen-containing fuels. Post-combustion homogeneous reactors for crevice-based oxidation and exhaust blowdown revealed significant NO and N2O formation after the end of combustion at moderate temperatures (850–1200 K), suggesting that N2O formation was dominated by secondary thermal processes. Therefore, the inclusion of post-combustion chemistry and more consistent models are essential for accurate emission prediction in NH3-fueled SI engines.
Trujillo Grisales, Juan, Saenz Prado, Stefany, Alvarez, Luis F., Akkerman, Vyacheslav, Dumitrescu, Cosmin E.
Performance and Combustion Characteristics of Coryton SUSTAIN Classic Super 80 Carbon-Neutral Fuel versus EN 228 in a 1980s Fiat 500 Engine2026-37-00336/9/2026
The energy transition requires a rapid reduction in the use of fossil fuels, whose combustion generates substantial greenhouse-gas emissions. In Europe, transport alone accounts for roughly a quarter of total greenhouse-gas emissions, with road transport being the predominant component. In this context, the use of biofuels has emerged as a potential solution for limiting further increases in CO₂ emissions. However, most studies available in the literature evaluate the performance of these fuels on modern engines, while their effects on historic carburetted engines remain largely unexplored. This is particularly significant given the large fleet of historic vehicles across Europe, supported by a long-standing tradition of vehicle preservation, associations, and classic car collectors. The main historic-vehicle federations advise caution and the use of low-ethanol formulations so as not to damage elastomers, fuel tanks, and carburettor float bowls. For this reason, a few suppliers have developed fuels specifically for classic vehicles. Among this minority, in 2023 Coryton Advanced Fuels introduced the SUSTAIN Classic line, including the Super 80 variant. In the present study, the performance, fuel consumption, and emissions of an air-cooled, four-stroke Fiat 500 engine fueled with commercial RON 95 gasoline and Coryton SUSTAIN Classic Super 80 were analyzed. A first test comprised a complete sweep from 1000 to 5000 RPM and a second test evaluated four different main jets at maximum torque speed and maximum power speed. To evaluate the performance, the engine was installed on a test bench equipped with a torque meter. Static pressure and temperature sensors were employed to characterize the engine operating conditions, while a dynamic pressure sensor installed in the combustion chamber was used to analyze the combustion characteristics. Exhaust emissions were also measured using a gas analyzer, allowing for a detailed and accurate comparison of the effects associated with the use of the two fuels.
Tarchiani, Marco, Fossati, Federico, Raspanti, Sandro, Baroni, Alberto, Ferrara, Giovanni, Romani, Luca
An Open-Source Framework to Automate Virtual Optimization of Internal Combustion Engine Calibration Maps through Shape-Based Strategy2026-37-00016/9/2026
The automotive industry is facing increasingly stringent regulatory constraints, driving the need for faster and more efficient powertrain development. This results in higher systems complexity, making internal combustion engine calibration progressively more challenging to meet performance and emissions targets. This, combined with the manual nature of traditional calibration workflows, leads to a time-consuming process that heavily relies on human expertise. Although virtualization can reduce development time and costs, the overall workflow remains largely dependent on manual decision-making and iterative refinement. In this context, this work presents a virtual calibration framework based on a genetic algorithm, aimed at the automated optimization of engine calibration maps to satisfy performance and emissions constraints, while reducing manual effort. Each calibration map is represented through a polynomial parameterization. Specifically, a generic three-dimensional polynomial with map-specific order encodes the shape of each map, ensuring smoothness which directly impact on drivability. Accordingly, the calibration problem is reformulated as the optimization of a compact set of polynomial parameters that uniquely define the full set of calibration maps, rather than individual set-point. Each candidate solution is assessed by generating the corresponding calibration maps and simulating the engine behavior through a neural-network-based digital twin, providing predictions of operating conditions, hardware limits, performance metrics, and emissions. The proposed framework was validated on a passenger-car diesel engine, considering a reduced yet representative set of calibration maps, including main injection start of injection, air mass, boost pressure, and injection rail pressure. The objective of optimization was the minimization of brake mean fuel consumption, subject to an upper bound constraint on nitrogen oxides emissions. The global optimization process explored approximately 106 different calibration candidates within about 36 hours, leveraging parallel computation on a standard laptop. The results indicate that the procedure can deliver multiple near-optimal preliminary calibration solutions, providing an effective starting point for subsequent manual finetuning.
Romano, Gianvito, Aglietti, Filippo, Spedicato, Tonio, Cozza, Ivan Flaminio, Capra, Andrea
Hybridized Diesel Powertrains - An Important Enabler for Commercial Applications on the Long Journey towards Full Electrification2026-37-00226/9/2026
The ongoing efforts for reduction of the traffic-related greenhouse gas emissions and, at the same time, the mitigation of harmful pollutant emissions from vehicle exhaust emissions are important development tasks for the entire automotive industry worldwide according to demand to provide clean and efficient products. Further tightened fleet average FE standards and ultra-low limits for exhaust emissions require the continuous development of new propulsion system types. Due to the given reluctance of the end customer and corresponding low acceptance of fully electrified vehicles, especially in the commercial vehicle segment, new and innovative topologies are needed to meet regulatory requirements and maintain the high versatility of today’s dominating solutions. For further optimization of operating conditions with enhanced fuel efficiency, the technical strategy is also determined by uplifting the attractiveness of electric driving incl. the avoidance of areas with poor ICE efficiency and as well as the coverage of emission-critical operations by electric propulsion. In this context, the support provided by an electric drive on board the vehicle in a combined drive system is becoming increasingly important. This article discusses accordingly various platform strategies for hybridized Diesel powertrains in different sectors of commercial vehicle applications and delivers a comprehensive comparative analysis of different hybrid drive concepts. Specifically, several hybrid powertrain configurations that extend an electric drive platform (hybridized BEVs), such as series and parallel-series topologies, are compared with traditional parallel hybrid powertrain topologies based on internal combustion engines (ICE). The study focuses mainly on two different cornerstone applications: a large light commercial vehicle, ranging from 3,5 to 6,5 to. and a heavy-duty long-haul truck with 40…44 to. gross vehicle weight. It evaluates the advantages in terms of CO2 emissions and Diesel fuel savings and investigates the effects on emission controls aspects. In addition to technical comparisons, the paper addresses also regulatory demands and end customer merits, assessing the integrational effort and commonalities in components with pure ICE and battery electric topologies. Furthermore, it explores the additional impact of advanced operational strategies for Hybrid Diesel powertrains, incorporating insights from innovative observations from executed hybrid technology demonstrator vehicles.
Koerfer, Thomas
Comparative Toxicological Assessment of Exhaust Emissions from Modern Low-Emission Passenger Vehicles2026-37-00056/9/2026
As vehicle technologies evolve toward electrification and advanced aftertreatment, understanding the biological implications of their exhaust emissions remains essential. This study presents a harmonized comparative toxicological assessment of five Euro 6 vehicles representing gasoline, hybrid, plug-in hybrid, compressed natural gas (CNG), and diesel technologies. Vehicles were tested under realistic driving conditions on a chassis dynamometer. Diluted exhaust was delivered directly to human lung epithelial cells (A549) using a controlled air–liquid interface (ALI) exposure system. Solid and total particle number emissions were measured, and deposited particle mass was estimated from size-resolved distributions and deposition efficiency. Vehicles equipped with particulate filtration showed lower solid particle emissions overall, while differences between gasoline particulate filter-equipped vehicles indicated that hybridization can further influence emission levels. Diesel operation during active diesel particulate filter (DPF) regeneration produced more than two orders of magnitude higher particle number emissions compared to normal operation. When expressed as deposited mass, vehicle ranking differed from number-based emissions, highlighting that emission metrics do not directly translate into delivered biological dose. Exposure to whole exhaust consistently induced stronger cytotoxic and inflammatory responses than to gaseous phase alone. Membrane integrity disruption and IL-1β release showed clear particle-associated amplification, with the strongest effects observed during diesel DPF regeneration. These findings demonstrate persistent technology-dependent differences in particle emissions and acute biological responses among modern low-emission vehicles.
Tsakonas, Georgios, Stamatiou, Rodopi, Lazou, Antigone, Samaras, Zissis, Elihn, Karine
Investigating the Potential of Two Individually Controlled Injectors per Rotor for a Direct Injection Hydrogen Wankel Engine2026-37-00086/9/2026
Hydrogen-fueled rotary engines offer a promising zero-emission solution for compact commercial powertrains. This study reports experimental results from the further development of a naturally aspirated, direct-injection hydrogen rotary engine by HTM. Initial applications, such as an airport baggage tractor, demonstrated technical feasibility but revealed pre-ignition that limited maximum torque. To address this, mixture formation was investigated using an experimental setup with two independently controlled injectors feeding a single rotor injection channel. The effects on operating behavior, efficiency, and NOx emissions were evaluated. The dual-injector configuration significantly shortens injection duration and improves spatial distribution of hydrogen within the combustion chamber. Enhanced mixture control suppresses pre-ignition and enables higher mean effective pressure. Systematic variation of injection timing under representative steady-state conditions also shows potential for NOx reduction through differentiated injector operation. In-cylinder pressure analysis and exhaust gas measurements provide detailed insight into combustion characteristics and abnormal events. The dual-injector setup increases torque capability and operational robustness without additional mechanical complexity, supporting the use of hydrogen rotary engines in compact hybrid systems and stationary power applications.
Endres, Jonas, Beidl, Christian, Herold, Tim, Lavall, Philipp, Schmidt, Marvin, Hofmann, Silas, Kahl, Jonas
Alcohol-Based Energy Carriers in Transportation: Status, Standards, and Outlook2026-37-00426/9/2026
The global transport sector accounts for approximately 30 % of total final energy consumption and 15.9 % of worldwide greenhouse gas (GHG) emissions, with road transport alone accounting for the largest share at 11.8 %. Decarbonizing this sector requires energy sources that combine scalable generation from renewable sources with compatibility with various modes of transportation and existing infrastructure. Methanol and ethanol emerge as promising alternative energy carriers that can leverage existing logistics infrastructure while reducing dependence on fossil fuels. Global methanol production reached 112 million metric tons, and global ethanol production totaled approximately 93.5 million metric tons in 2024, compared to more than 2 billion metric tons of gasoline and diesel produced annually. The review assesses production pathways and cost trajectories for both alcohols, evaluates fuel requirements across multiple transport modes, including passenger vehicles, light- and heavy-duty vehicles, maritime shipping, aviation, and rail, and provides regulatory frameworks governing fuel standards in six major markets, the European Union, the USA, Brazil, China, Japan, and India. From a technical perspective, the internal combustion engine is examined in greater detail as the energy conversion system, synthesizing current combustion research on engine performance, emissions characteristics, and cold-start behavior. Current standards predominantly accommodate ethanol blending for spark-ignition (SI) engines in passenger vehicle applications, with permitted concentration limits ranging from 3 % in Japan to nearly pure ethanol in Brazil. Methanol applications remain more limited in road applications. In the maritime sector, recent ISO 8217:2024 specifications and International Maritime Organization (IMO) interim guidelines have established frameworks for the use of methanol and ethanol as marine fuels. Aviation remains the most restrictive sector, with alcohol fuels explicitly prohibited in certified aviation fuels due to material compatibility and safety concerns. To unlock the decarbonization potential of methanol and ethanol in the transport sector, coordinated policy support and continued technological innovation will be essential. As production scales and regulatory frameworks mature, both alcohol fuels may play an increasingly central role in the transition toward sustainable mobility.
Fitz, Patrick, Fellner, Felix, Rößlhuemer, Raphael, Härtl, Martin, Jaensch, Malte
Methane Emission Mitigation in Large-Bore Dual-Fuel Engines via Negative Valve Overlap Diesel Injection: Thermochemical Pathways and Reactivity Control2026-37-00456/9/2026
Low-load natural gas–diesel reactivity controlled compression ignition (RCCI) in medium-speed marine engines is constrained by an insufficient charge thermal state. This limitation leads to partial fuel oxidation, producing high methane emissions. This work evaluates the use of negative valve overlap (NVO) combined with NVO diesel injection as an in-cylinder reactivity enhancement strategy. The simulation study was performed using the University of Vaasa’s advanced thermo-kinetic multi-zone model (UVATZ), extended for reactive simulations during NVO. The extended framework was validated against test-bench data from a prototype Wärtsilä 6L20 dual-fuel engine operating in RCCI mode. The baseline low-load operating point for reforming simulations was defined by reducing the intake manifold temperature to replicate conditions close to partial misfire with 52% combustion efficiency. The parametric sweeps of NVO injection timing and ratio showed that the strategy can be used for in-cycle fast thermal management, effectively restoring complete combustion on an individual cycle basis. In simulated conditions, the best performance was obtained with an NVO injection ratio of 0.3, with the injection scheduled before top dead center. In contrast, increasing the NVO fraction beyond ~0.3 provided no benefit and led to complete misfire due to excessive reduction of main-event high-reactivity fuel. The simulations revealed a coupled thermal–chemical control mechanism. Early NVO injections stabilize combustion through recompression heat release and an increased next-cycle intake valve closing temperature. Sufficiently late injections stabilize combustion by carrying unreacted diesel into the subsequent cycle. Injections near NVO TDC primarily undergo fuel conversion to CO, H2O, and unsaturated light/mid-range hydrocarbons with negligible thermal boost, yielding an overall reactivity deficit.
Soleimani, Amir, Nurmi, Mikael, Hunicz, Jacek, Kim, Jeyoung, Hyvonen, Jari, Mikulski, Maciej
Predictive Modelling of NO x and Unburned Hydrogen Emissions in a Direct-Injection Hydrogen Spark-Ignition Engine2026-37-00076/9/2026
Hydrogen is emerging as a compelling energy carrier for future transportation due to its potential to enable fully decarbonised operation and near-zero tailpipe pollutant emissions. Realising this potential in reciprocating internal combustion engines requires a detailed understanding of the complex interactions governing hydrogen combustion and emissions formation. In this context, physics-based reduced-order emission predictive modelling offers a powerful means to accelerate the development and optimisation of hydrogen-fuelled engines by enabling rapid evaluation of operating strategies without the need for extensive experimental campaigns. This study investigates the simulation of nitrogen oxides (NOx) and unburned hydrogen (uH2) emissions from a 0.5L spark-ignition direct injection single-cylinder research engine within a 1D-0D simulation approach. For NOx prediction, a simplified kinetic mechanism is coupled with both a 0D two-zone combustion model and a thermal multi-zone in-cylinder representation, enabling assessment of the need to account for temperature stratification for accurate prediction. For uH₂ emissions, phenomenological sub-models describing flame wall quenching and top-land crevice mechanisms are implemented and calibrated to capture the dominant sources of hydrogen escape during combustion. The models are validated against an experimental dataset spanning a wide range of engine conditions, including variations in engine load, relative air–fuel ratio from stoichiometric to ultra-lean combustion, dilution via exhaust gas recirculation, and spark timing. The comparison highlights the models' ability to reproduce observed physical trends across different engine operating conditions for both NOx and uH2. Regarding NOx emissions, the accounting of temperature stratification with the multi-zone model enables more accurate predictions of trends and absolute values. The uH2 model provides fundamental insights into hydrogen engine flame propagation by highlighting the need for flame propagation in the top-land crevice at richer λ to reproduce observed trends. Overall, the study provides insights into both hydrogen-specific emission mechanisms and key modelling requirements for accurate pollutant simulation in hydrogen engines.
Malfi, Enrica, De Felice, Massimiliano, Esposito, Stefania, Ribnishki, Aleksandar, King, Aidan, Akehurst, Sam, Jones, Peter, Goyal, Harsh
Development and Experimental Validation of a 1D Model for Performance and Emissions Analysis of Oxygenated Fuel Blends in a CI Engine2026-37-00286/9/2026
Emissions reduction remains a major concern for internal combustion engines in view of increasingly stringent environmental regulations. To address these challenges while maintaining acceptable engine performance, a wide range of alternative fuels and fuel blends have been investigated to ensure the continued viability of CI engines. This study reports the effects of blending the oxygenated fuel diethylene glycol diethyl ether (DGDE) with hydrotreated vegetable oil biodiesel (HVO) on engine performance and emissions. The investigation is conducted on a 2.3-liter, four-cylinder, common-rail diesel engine, equipped with a variable geometry turbocharger and a high-pressure exhaust gas recirculation system. The objectives of this study are achieved by developing a one-dimensional predictive engine model using the commercial GT-SUITE software. The engine model is developed and experimentally validated, at various operating conditions and HVO–DGDE fuel blends, to predict their effects on combustion characteristics and emissions formation. The validation is performed against measurements collected at the engine test bed. The results indicate that increasing the blending ratio of oxygenated fuel leads to improvements in indicated mean effective pressure and a more favorable Soot–NOx emissions trade-off compared with neat HVO operation. The findings highlight the potential of oxygenated fuel blends to enhance CI engine performance while reducing emissions. This study demonstrates the effectiveness of combining experimental and numerical approaches to evaluate biodiesel–oxygenated fuel blends and provides insights for future research aimed at minimizing CI engine emissions.
Arain, M Wajahat Rasool, Foglia, Antonio, Frasci, Emmanuele, Vitek, Oldrich, Pianese, Cesare, Arsie, Ivan
A Parametric Cradle-to-Grave Life Cycle Assessment Tool for Comparative Evaluation of Passenger Car CO₂ Emissions2026-37-00406/9/2026
This work presents the development of a user-oriented software tool for the cradle-to-grave Life Cycle Assessment (LCA) of passenger cars, enabling robust comparisons of greenhouse gas emissions across heterogeneous vehicle configurations. The tool supports informed decision-making by quantifying and visualizing environmental impacts associated with alternative mobility choices over the full vehicle life cycle, including production, use, maintenance, and end-of-life stages. The proposed framework allows key parameters describing both the vehicle and its usage to be explicitly defined, including powertrain type, dimensions and weight, ownership profile (new or second-hand vehicles, partial ownership periods, leasing scenarios), annual mileage, vehicle lifetime assumptions, and the carbon intensity of fuels or electricity sources. Country-specific energy mixes are incorporated, enabling the same vehicle to be assessed under different geographic contexts and highlighting the strong dependence of use-phase emissions on local energy systems. Results are reported both as total life-cycle emissions and as a phase-resolved breakdown, improving transparency and supporting a clear interpretation of trade-offs between production, operation, maintenance, and end-of-life stages. Representative scenarios demonstrate that, under a standard European context, battery electric vehicles (BEVs) achieve a reduction of approximately 32% in yearly greenhouse gas emissions compared to a baseline Euro 5 gasoline vehicle. However, this trend reverses for low-mileage users relying on second-hand vehicles, for which emissions can increase by about 15%, emphasizing the critical role of usage patterns and ownership strategies in determining environmental benefits. The tool is designed to accommodate updated datasets, emission factors, and evolving energy scenarios, ensuring long-term applicability and enabling forward-looking analyses. Its capabilities are demonstrated across scenarios covering short- and long-term usage, multiple national contexts, and different powertrain technologies. The result is a robust and transparent assessment platform that enables users and policymakers to evaluate vehicle replacement strategies, providing quantitative insights into the interplay between technology, usage, and sustainability in mobility transitions.
Gastaldi, Chiara, Cibrario, Luca
Engine Thermal Management Strategies for Emissions Reduction during Real Driving Tests2026-37-00366/9/2026
Thermal management in internal combustion engines (ICEs) strongly affects fuel consumption and pollutant emissions, especially during engine warm-up. Particularly, the oil temperature is strictly related to the organic efficiency of the vehicle: in the early phase of a driving cycle, the low temperature produces a high-viscous oil, which increases friction losses and increases fuel consumption, with respect to full thermal regimated oil. Usually, the oil and coolant thermal behaviours are interconnected, thanks to a coolant/oil heat exchanger in the engine. In this study, a prototyped electrical coolant pump has been applied and integrated in a small SUV vehicle, replacing the original mechanical unit. An off-board experimental campaign allowed a complete hydraulic characterization of the cooling system, including thermostat operation, and led to a physically based correlation between flow rates and pressure drops in each branch. Based on these results, the pump was designed and prototyped, enabling advanced flow management strategies on board. On-road Real Driving Emissions (RDE) tests were carried out using different pump control logics. Four different control strategies have been proposed in order to reduce the warm up time of the engine and the oil. Results show that the warm-up time reduction produces also a decrease in CO, NO, THC, CH₄, and PN emissions by 15–65%, particularly during cold-start conditions. The innovation proposed can be also combined to other technological options, to further improve the thermal behaviour of the engine and increase the temperature of the oil in the early phase of a common driving cycle. Electrification also reduces parasitic losses and facilitates integration with hybrid powertrains, confirming thermal management as an effective transitional technology for improving ICE efficiency and environmental performance under real driving conditions.
Di Battista, Davide, Di Bartolomeo, Marco, Cipollone, Roberto
Forecasting Electric Vehicle Fleet Growth and Energy Requirements in the UK2026-37-00436/9/2026
With the United Kingdom’s goal to achieve a fully decarbonised energy sector by 2035 and achieve net zero greenhouse gas emissions by 2050, the transition of the UK’s passenger car fleet to battery electric vehicles (BEVs) plays a crucial role in reaching this goal. This study evaluates the environmental and energy impact of large-scale BEV adoption by modelling future uptake scenarios using historical fleet data combined with assumed impact of future policy such as the 2030 ban on the sale of new petrol and diesel vehicles. Three predictive models have been developed: fast uptake, in which approximately 100% of the passenger car fleet is replaced by BEVs; moderate uptake, where a large majority of passenger cars are BEVs; and slow uptake, in which BEV adoption does not reach a majority. The results have shown that, if a medium- or large-scale adoption is possible by 2040 predicting nearly 37 million BEVs on the road, the associated electricity demand is predicted to rise close to 110 TWh annually, signifying the need for rapid development in renewable energy generation. Although BEVs significantly reduce transport sector emissions, the overall climate impact is dependent on a continued effort of grid decarbonisation.
Burke, Bradley, Kateregga, Sunny, Sodre, Jose Ricardo
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