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Currently 99.8 % of global transport is powered by internal combustion engines (ICEs) and 95% of transport energy comes from liquid fuels made from petroleum. Many alternatives including battery electric vehicles (BEVs) and other fuels like biofuels and hydrogen are being considered. However, all these alternatives start from a very low base and fa...
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As CO2 emission regulations increase, fleet owners increasingly consider the adoption of Electric Vehicle (EV) fleets in their business. The conventional Vehicle Routing Problem (VRP) aims to find a set of routes to reduce operational costs. However, route planning of EVs poses different challenges than that of Internal Combustion Engine Vehicles (...
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... The internal combustion engine is one of the main sources of urban air pollution. During the operation of gas internal combustion units, the main air pollutants produced are NOx (nitrogen oxides), accompanied by a small amount of SO2 and CH4 and other gases [6][7]. Nowadays, NOx and SO2 have become important air pollutant control indicators for internal combustion engines, while CO and CH4 are gas components that characterize the combustion state of internal combustion engines [8][9]. ...
Natural gas-fired internal combustion engines (ICEs), as an alternative to traditional fuel-fired ICEs, are a technological innovation to implement the “double reduction” policy by utilizing clean energy. The academic community is interested in the topic of controlling air pollutant emissions from natural gas internal combustion engines. In this paper, a three-dimensional model of internal combustion engine operation and a natural gas hydrodynamic model are constructed successively, and numerical simulation is carried out using fluent software. A non-dominated genetic algorithm is introduced to solve the air pollutant emission control problem of the internal combustion engine, and the Pareto optimal solution of pollutant emission is determined by the TOPSIS decision-making method. The error of the numerical simulation results in this paper is less than 5%, and the maximum transient temperature of the natural gas internal combustion engine is approximately 1940 K. The NO x generation has a double hump-like distribution. In the case of Pareto’s optimal solution, the system efficiency of the new scheme is 56.82%, the carbon dioxide emission rate is 353.31kg/(Mwah), and the total annual cost is 6.45×10 ⁸ ¥, which is better than the original scheme, which verifies the effectiveness of the proposed method.
... The overall CO 2 emissions of light-duty vehicles can be reduced by increasing internal combustion engine efficiency and using fuels and fuel sources that are less carbon-intensive [1]. Knocking, unwanted and uncontrolled autoignition of end gas (the portion of the fuelair mixture ahead of the flame), is one of the main factors limiting engine operation and efficiency [2]. ...
... Vehicles manufactured before 2000 recorded carbon dioxide emissions (ICD and DCD) approximately 11 times higher and hydrocarbon emissions (IHC and DHC) over 4 times higher compared with the post-2020 vehicles analyzed in this study (see Table 2). This pattern may be attributed to the progressive implementation of advanced emission treatment systems, control technologies, and more efficient combustion processes in modern engines, reducing pollutant emissions [2,33,34]. ...
Vehicle emissions pose significant environmental challenges, particularly in high-altitude regions, where atmospheric conditions amplify pollutant concentrations. This study evaluates CO2 and hydrocarbon (HC) emissions from 79 gasoline-powered vehicles in Guaranda, Ecuador (2668 m.a.s.l.), by using STATIS, a multivariate statistical method. The vehicles were classified into six model year intervals and tested under idle and dynamic conditions, measuring idle CO2 and HC (ICD and IHC) and dynamic CO2 and HC (DCD and DHC). The results showed that vehicles manufactured before 2000 exhibited the highest emissions, with ICD of 3.18% vol. and IHC of 414 ppm, while vehicles produced after 2020 showed significantly lower values (ICD of 0.27% vol. and IHC of 101.44 ppm). Additionally, Chevrolet was the most represented brand, accounting for 41.78% of the analyzed sample, while 34.18% of the vehicles were from the 2010–2015 interval. The STATIS model revealed structural similarities among the 2000–2005, 2016–2019, and post-2020 models, whereas pre-2000 vehicles differed markedly from the 2010–2015 models. Outliers, including older vehicles with low emissions and newer models with unexpectedly high emissions, highlighted the role of maintenance and operational conditions. These findings demonstrate the effectiveness of STATIS in analyzing complex emission patterns and underscore the need for future studies that incorporate variables such as mileage and environmental factors to refine emission mitigation strategies.
... Additionally, the horizontal section contains a catalytic unit consisting of a diesel oxidation catalyst (DOC) with dimensions of 9.5 cm in diameter and 9 cm in length. The DOC features a cell density of 400 cells per square inch (cpsi) and contains precious metal loaded at 10 g/ft 3 , with a washcoat loading of 2.6 g/inch 3 . This geometry has also been used in our earlier work 28 . ...
Exhaust aftertreatment systems (EATS) play a critical role in reducing emissions and ensuring compliance with stringent emission regulations. Catalytic converters, as part of EATS, involve complex physico-chemical processes. To accurately predict their behavior in realistic geometries, transient 3D models are necessary. However, the computational cost associated with simulations based on such models prevents their application to long-time behaviors as well as in real-time control and diagnostics. While single-channel models (SCMs) are computationally efficient, they struggle to provide accurate predictions during real-time operations with flow maldistribution. In this study, we propose a pseudochannel model derived using steady-state reactive 3D simulations and a nonlinear least squares optimization technique. We show that the performance of this pseudochannel model is superior to a conventional SCM in both transient and steady state test cases. At the same time, the computational cost of the pseudochannel model is equivalent to that of the SCM. These results imply that flow maldistribution effects can be well incorporated in SCMs via a pseudochannel approach that relies on relatively inexpensive steady-state system data.
... The demand for transportation has experienced a substantial increase over the past decade, primarily attributable to global population growth, with projections indicating that the number of internal combustion engine (ICE) vehicles will escalate from 1.7 to 2 billion by the year 2040 [1]. As per the 2023 data, the transportation sector remains predominantly dependent on petroleum products, which constitute approximately 91% of its aggregate energy consumption, comprising about 106.41 EJ of petroleum derivatives, 5.25 EJ of natural gas, 4.18 EJ of biofuels, and 1.65 EJ of electricity utilized. ...
In line with Libya's strategic shift towards renewable energy and efforts to reduce carbon emissions, and considering that the transportation sector is the second-largest contributor to environmental pollution after the electricity sector, this study aims to explore the feasibility of adopting electric vehicles (EVs) as a strategic solution to enhance environmental sustainability and reduce dependence on fossil fuels. This research analyzes the energy consumption of electric vehicles under real-world climatic and operational conditions, focusing on the impact of wind resistance, road incline, rolling resistance, and acceleration resistance on energy efficiency. The Brak-Sabha highway in southern Libya was selected as a case study, where an 83 km simulated journey over 60 minutes was assessed under four distinct weather conditions: stormy, cold, hot, and rainy, considering both daytime and nighttime driving. In the present stydy, the energy consumed in electric vehicles was classified into two levels: high voltage (400 volts) to operate the electric motor and its accessories, and low voltage (12 volts) to operate the auxiliary devices. The results indicate that wind resistance had the most significant impact on energy consumption, accounting for 74.8% of total resistance, followed by road incline (14.4%), rolling resistance (10.3%), and acceleration resistance (0.5%). The study also revealed that auxiliary systems, such as heating, cooling, and lighting, significantly increase energy consumption, reaching 3.61 kWh during winter nighttime driving, whereas the lowest recorded consumption was 1.86 kWh during daytime summer trips. In the worst operational scenario, total energy consumption surged from 18,476.63 Wh under normal conditions to 86,800 Wh, reflecting a 370% increase, emphasizing the substantial impact of extreme weather conditions on energy usage. The findings highlight the necessity of optimizing driving strategies and energy management to enhance electric vehicle efficiency and extend operational range.
... For transportation sectors that are difficult to electrify, such as rail, marine, and aviation, innovative combustion engine systems that can reduce carbon emissions are also essential. In fact, as recent studies indicate, ICEs remain the dominant type of powertrain being sold and utilized in the world (Leach et al. 2020;Kalghatgi 2018). Various projections also indicated that by 2040, the global number of passenger vehicles will exceed 2 billion, with most of them still relying, at least in part, on ICEs (Kapustin and Grushevenko 2020). ...
Quantifying the similarity of velocity vector fields is a critical task across numerous applications within fluid mechanics research, such as computational fluid dynamics validation and quantifying the levels of variability in a flow field. However, this task remains challenging for widely used vector comparison metrics at present. Traditional metrics include the Relevance Index (RI) and Magnitude Similarity Index (MSI) as well as their local versions, Local Structural Index (LSI) and Local Magnitude Index (LMI). These metrics, however, are often sensitive to low-velocity magnitude areas, which can distort the results. To address this, improved metrics like the Weighted Relevance Index (WRI), the Weighted Magnitude Index (WMI), and their amalgamated Combined Magnitude And Relevance Index (CMRI), have been introduced in the literature. Despite having reduced sensitivity to low-velocity areas, CMRI in its original form does not equally consider the significance of WRI and WMI, and introduces a degree of subjectivity. In the present work, we propose two enhanced metrics to address this problem: the modified CMRI for one-by-one flow field comparison, and the ensemble CMRI for comparing collections of vector fields. We compare their properties to the previously developed CMRI and spatially averaged CMRI, and investigate their usage in an applied example for quantifying cyclic variations in a flow from a combustion engine cylinder. The newly proposed metrics were found to more robustly isolate the effects of discrepant vector magnitudes and directions, leading to improved diagnostics of in-cylinder flow fields. In particular, the modified CMRI, which ensures equal treatment of WMI and WRI, can serve as a baseline for flow field comparison, providing a more objective target for quantifying flow similarity.
... Despite these barriers, several technological advancements, innovative methods, and improvement approaches have emerged as potential solutions to reduce air pollution from these industries while maintaining profitability. One key strategy is enhancing combustion processes by integrating technologies such as low-NO x burners and wet or dry flue gas desulfurization systems into existing combustion units to reduce the formation of primary air pollutants, among other approaches, such as water injection, air staging, flow gas recirculation, low excess air, oxy-fuel combustion, fuel staging, and chemical looping combustion [109][110][111][112]. Additionally, advanced process control systems can be used to monitor and adjust the combustion parameters in real time, ensuring the optimal efficiency and minimizing pollutant emissions [111,112]. ...
Petroleum refining and petrochemical complexes are significant sources of air pollution, emitting a variety of harmful pollutants with substantial health risks for nearby populations. While much of the information regarding this issue and the potential health impacts of this pollution has been documented, it remains fragmented across studies focusing on specific regions or health outcomes. These studies are often clustered into meta-analyses or reviews or exist as undeclared knowledge held by experts in the field, making it difficult to fully grasp the scope of the issue. To address this gap, our review consolidates the existing knowledge on the sources of air pollution from petroleum refining and petrochemical industries, the main pollutants involved, and their associated health outcomes. Additionally, we conducted an umbrella review of systematic reviews and meta-analysis and also included critical reviews. With this approach, we identified 12 reviews that comprehensively evaluate the health impacts in populations living near petroleum refining and/or petrochemical complexes. These reviews included studies spanning several decades (from 1980 to 2020) and encompassing regions across North America, Europe, Asia, South America, and Africa, reflecting diverse industrial practices and regulatory frameworks. From these studies, our umbrella review demonstrates that residents living near these facilities face elevated risks related to leukemia, lung and pancreatic cancer, nonmalignant respiratory conditions (such as asthma, cough, wheezing, bronchitis, and rhinitis), chronic kidney disease, and adverse reproductive outcomes. Furthermore, we discuss the key challenges in mitigating these health impacts and outline future directions, including the integration of cleaner technologies, which can significantly reduce harmful emissions; strengthening policy frameworks, emphasizing stringent emission limits, continuous monitoring, and regulatory enforcement; and advancing research on underexplored health outcomes. This review emphasizes the need for coordinated global efforts to align the industry’s evolution with sustainable development goals and climate action strategies to protect the health of vulnerable communities.
... Concerning future sustainable mobility, several hard-toelectrify applications in the transportation sector and machinery usage, e.g., heavy duty off-road applications, still require the use of dense liquid fuels [1][2][3][4]. In 2019, the global transportation sector was the fourth largest source of greenhouse gas emissions and made up roughly 15 % of total greenhouse gas emissions [4]. ...
... Hence, the transport sector is heavily reliant on combustion engines and therefore on liquid fuels. More than 50 % of the global transport energy demand is encompassed by heavy duty, marine, and air transport [2,3]. ...
Oxymethylene dimethyl ethers (OMDME) have attracted interest as renewably synthesized diesel substitutes with low soot formation and NO x emissions. In order to enable a high compatibility of this new type of fuel in the already existing infrastructure, a modified oxymethylene ether (OME) synthesis based on technical alcohol mixtures, i.e., C 4 ‐based alcohol mixtures of isomers, was evaluated and the new compounds were thoroughly characterized. The synthesized compounds can be used as neat fuel or as blending component for fossil or paraffinic diesel fuels. The modification of OME offers the possibility to adjust desired properties. This versatility could also be used to synthesize compounds for the chemical sector according to its respective requirements, such as applications as solvents, plasticizers, or additives.
... Internal combustion (IC) engines are known for their excellent thermal efficiency, wide power range and good fuel economy and they are widely used as power sources in many engineering sectors [1,2]. However, rapid advancements in science and technology have led to increased energy consumption and pollution. ...
Diesel engines are frequently used because of their high efficiency and durability. However, they are also known for emitting high amounts of pollutants, including CO2, CO, NOx and particulate matter. Current studies have focused on alternate fuel techniques to reduce these emissions. An effective method involves using oxyhydrogen (HHO) with diesel and biodiesel can increase combustion efficiency and minimize harmful emissions. Additionally, HHO serves as a viable alternative to hydrogen, especially considering the current challenges in global hydrogen production and storage, which may not be sufficient to meet the increasing demand for transportation applications. Hence, the current study investigated the effect of using a diesel-HHO dual fuel on the emission characteristics of a single-cylinder, four-stroke diesel engine. The engine was operated at a constant speed of 1500 rpm and was tested under varying loads of 0%, 50% and 75%, with diesel (D100) serving as the primary fuel and HHO gas as the inducted fuel. The HHO gas, produced at a constant flow rate of 0.80 LPM through alkaline water electrolysis was continuously injected into the combustion chamber through air suction manifold. The results revealed that compared to diesel fuel, the injection of HHO has increased the CO2 emissions by 23.08, 23.81 and 20.0% at an engine load of 0, 50 and 100%. The CO emissions were reduced by 23.53, 34.78 and 41.38% at 0, 50 and 100% engine load. Similarly, the HC emissions were reduced by 26.09, 23.08 and 23.33% at 0, 50 and 100% engine load. The NOx emissions were increased by 25.0, 10.53 and 4.17% at 0, 50 and 100% engine load. Overall, introducing HHO has increased the CO2 and NOx emissions as the hydrogen and additional oxygen in the HHO gas promote more complete combustion and higher combustion temperatures. However, this enhancement in combustion efficiency has resulted in a significant reduction in CO and HC emissions.
... 1 Despite increasing electrification of the global transport fleet, the vast majority of vehicles still use fossil fuelpowered internal combustion engines (ICEs). 2 It is therefore crucial to increase the efficiency of ICEs to ensure that fuel consumption and the subsequent CO 2 emissions are minimized. 3 A major issue affecting the efficiency of modern ICEs are deposits that form on metal surfaces inside the engine, particularly those on the fuel injectors. 4 These deposits have long been recognized as a problem in diesel-powered compression ignition ICEs, where recent attention has focused on internal injector deposits. ...
Engine deposits can reduce performance and increase emissions, particularly for modern direct-injection fuel delivery systems. Surfactants known as deposit control additives (DCAs) adsorb and self-assemble on the surface of deposit precursors to keep them suspended in the fuel. Here, we show how molecular simulations can be used to virtually screen the ability of surfactants to bind to polyaromatic hydrocarbons, comprising a major class of carbonaceous deposits. We use molecular dynamics with the adaptive biasing force method to generate the potential of mean force as a function of the vertical distance between the surfactants and deposits in gasoline and diesel fuel surrogates. We find that a zwitterionic surfactant outperforms a conventional polyisobutylene succinimide for binding to these aromatic species. The amine groups in the succinimide headgroup only weakly adsorb on the polyaromatic deposit, while additional functional groups in the zwitterionic surfactant, particularly the quarternary ammonium ion, markedly enhance the binding strength. We decompose the adsorption free energies of the surfactants into their entropic and enthalpic components, to find that the latter dominates the attraction from these non-aqueous solvents. The adsorption free energy of both surfactants is slightly weaker from n-hexadecane (diesel) than iso-octane (gasoline), which is due to the larger steric barrier from stronger molecular layering of the former on the deposit. Density functional theory calculations of the adsorption of DCA fragments validate the force field used in the molecular dynamics simulations and provide further insights into the nature of the intermolecular interactions. The approach introduced here shows considerable promise for accelerating the discovery of novel DCAs to facilitate more advanced fuel formulations to reduce emissions.
