Browse Topic: Greenhouse gas emissions
The future potential of an opposed-piston two-stroke (OP2S) engine has attracted the attention of researchers worldwide as it offers a high thermal efficiency and power-to-weight ratio with a simple engine configuration. This engine can be used with low-carbon fuels and hydrogen to reduce greenhouse gas emissions. However, the two-stroke operation has always been limited by its low scavenging efficiency and short-circuit of fresh charge. The current work is focused on optimizing scavenging efficiency and short-circuit in a small 200 cc single-cylinder OP2S SI engine using 3-D computational fluid dynamic (CFD) simulations. The effect of four parameters, namely, area of intake ports, area of exhaust ports, and angular orientations of intake ports (swirl and tilt) on scavenging efficiency and short-circuit, has been assessed and optimized. A Latin-hypercube based Design of Experiments (DoE) methodology is used to sample the design space spanning over a range of four parameters. A response
To achieve carbon neutrality, manufacturers need to estimate Greenhouse Gas (GHG) emissions generated throughout the life cycle of motorcycles, namely the Carbon Footprint of Product (CFP). We developed a method that allows calculation of the per-unit CFP and the total CFP of sales volume of motorcycles with a common formula, and also enables the estimation of their future values. First, we made it possible to calculate the per-unit CFP of each individual model by setting factors that we quantified the characteristics of motorcycles such as material composition and replacement parts and incorporating them into the calculation formula. Next, we enabled the calculation of the total CFP of sales volume from the present to the future by standardizing the specs of individual models and calculating the CFP by product category and multiplying the sales volume. Furthermore, we made it possible to simulate future CFP according to scenarios of expansion of environmental protection actions such
Shear-polarized ultrasonic sensors have been instrumented onto the outer liner surface of an RTX-6 large marine diesel engine. The sensors were aligned with the first piston ring at top dead center and shear ultrasonic reflectometry (comparing the variation in the reflected ultrasonic waves) was used to infer metal–metal contact between the piston ring and cylinder liner. This is possible as shear waves are not supported by fluids and will only transmit across solid-to-solid interfaces. Therefore, a sharp change in the reflected wave is an indicator of oil film breakdown. Two lubricant injection systems have been evaluated—pulse jet and needle lift-type injectors. The needle lift type is a prototype injector design with a reduced rate of lubricant atomization relative to pulse jet injectors. This is manifested as a smaller reduction in the reflected ultrasonic wave, showing less metal–metal contact had occurred. During steady-state testing, the oil feed rate was varied; the high flow
This study evaluates the performance of alternative powertrains for Class 8 heavy-duty trucks under various real-world driving conditions, cargo loads, and operating ranges. Energy consumption, greenhouse gas emissions, and the Levelized Cost of Driving (LCOD) were assessed for different powertrain technologies in 2024, 2035, and 2050, considering anticipated technological advancements. The analysis employed simulation models that accurately reflect vehicle dynamics, powertrain components, and energy storage systems, leveraging real-world driving data. An integrated simulation workflow was implemented using Argonne National Laboratory's POLARIS, SVTrip, Autonomie, and TechScape software. Additionally, a sensitivity analysis was performed to assess how fluctuations in energy and fuel costs impact the cost-effectiveness of various powertrain options. By 2035, battery electric trucks (BEVs) demonstrate strong cost competitiveness in the 0-250 mile and 250-500 mile ranges, especially when
Internal combustion engines are expected to continue to play an important on-going role in the future of transportation, particularly in long haul transit and off-road applications. Substantially reducing criteria emissions of heavy-duty (HD) commercial vehicle engines while also reducing fuel consumption is the quickest way to achieve more sustainable transportation. The opposed-piston (OP) engine developed by Achates Power has demonstrated the ability to meet the most stringent ultralow NOx emissions requirements using only a conventional, underfloor aftertreatment system, offering reduced cost, complexity and compliance risk compared to other diesel engines. This paper is focused on the measurement results of Achates Power heavy-duty engine achieving CARB proposed ultralow NOx emission for 2027 and 2031+ full useful life requirements while also meeting the EPA Greenhouse Gas (GHG) Phase 2 limits with a conventional aftertreatment system (ATS), which was aged to 435k, 600k and 800k
Decarbonized or low carbon fuels, such as hydrogen/methane blends, can be used in internal combustion engines to support ambitious greenhouse gas (GHG) emission reduction goals worldwide, including achieving carbon neutrality by 2045. However, as the volumetric concentration of H2 in these fuel blends surpasses 30%, the in-cylinder flame propagation and combustion rates increase significantly, causing an unacceptable increase in nitrogen oxides (NOx) emissions, which is known to have substantial negative effects on human health and the environment. This rise in engine-out NOx emissions is a major concern, limiting the use of H2 fuels as a means to reduce GHG emissions from both mobile and stationary power generation engines. In this study, an experimental investigation of the combustion performance and emissions characteristics of a 4th generation Tour split-cycle engine was undertaken while operating on 100% methane and various hydrogen/methane fuel blends (30%, 40%, and 50% by volume
The pollutant emission regulation for Non-Road Mobile Machinery (NRMM) is currently under consideration, both in the European Union (EU) and the United States (US). In Europe a Stage V review is expected within 2025 and in the US, the California Air Resource Board (CARB) has released their Tier 5 proposal in late 2024. It is expected that there will be further focus on covering a wide variety of operation conditions in actual use cases, including continuous low load scenarios. In addition, CO2-neutral fuels are being investigated to reduce the carbon footprint of NRMM Internal Combustion Engines (ICE), which remains an important powertrain for the sector. The objective of the work presented is to assess the potential for emissions reductions in the future, both NOx and CO2. A simulation study is conducted, modelling a 9l class engine with 8-10 g/kWh engine-out NOx emission level. Three different emission control systems are investigated: an enhanced stage V system with single SCR, a
In recent years, the stronger push for reducing GHG and NOx emissions has challenged vehicle manufacturers globally. In USA, Multi-Pollutant Emissions Standards for Model Years 2027 and Later Light Duty and Medium-Duty Vehicles released by EPA in April 2023 aims to reduce the CO2 emissions by 56% and 44%, respectively, for light and medium duty vehicles by 2032 from 2026 levels. It also includes the NMOG+ NOx standards, which require a 60 – 76% reduction by 2032 from 2026 levels for light to medium-duty vehicles. Europe also aims to reduce CO2 emissions by 55% by 2030 from 1990 levels and 100% by 2035. To achieve such low levels of CO2 emissions, especially in the near-term scenario of limited EV sales, hybridization of conventional powertrains has found renewed interest. While hybrid powertrains add complexity, if optimized well for the application, they can offer best tradeoff between upfront cost, range, payload, performance, emissions and off-ambient operation. This study
Marine ports are an important source of emissions in many urban areas, and many ports are implementing plans to reduce emissions and greenhouse gases using zero-emission cargo handling equipment. This paper evaluates the performance and activity profiles for various zero-emission (ZE) cargo transport equipment being demonstrated at different ports in California. This included 23 battery-electric (BE) 8,000 lb. (8K) and 36,000 lb. (36K) forklifts, a BE railcar mover, and an electrified rubber-tired gantry crane (eRTG). The study focused on evaluating the performance of the ZE equipment in terms of activity patterns and the potential emissions reductions. Data loggers were used to collect activity data, including hours of use, energy consumption, and charging information over periods from 6 to 21 months. The results showed that the BE forklifts, BE railcar mover, and the eRTG averaged 2-3 hours, 5 hours, and 14 hours of use per day of operation, respectively. The average energy use for
China 6b regulation was fully implemented since July 2023 with very strict emission standards for HC, NMHC, NOx, and CO. The country is now also in the process of developing China 7 regulation, which will perhaps impose even stricter emission limits and extra criteria pollutants including NH3. Moreover, increasingly strict fuel consumption regulation has been implemented as well and it is highly possible that greenhouse gas emission limits will be included in the China 7 regulation. With the hybrid technology innovation, PHEVs are effective in fuel economy and emission reduction, which are favored by manufacturers and consumers, and leading to a rapid increase in market share. Through the optimization of hybrid architecture and the synergy of electric motors, the operating conditions of the hybrid engine have been optimized, making it more stable and avoiding extreme engine operating conditions compared to traditional ICE, which also provides possibilities for optimizing the after
The Environmental Protection Agency’s Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) modeling tool was initially created to simulate the Greenhouse Gas emissions from light-duty vehicles. ALPHA is used to predict tailpipe CO2 emissions and energy consumption from advanced automotive technologies. ALPHA is a physics-based, forward-looking vehicle computer simulation tool capable of analyzing various vehicle types with different powertrain technologies while replicating realistic vehicle behavior. ALPHA version 3.0 is the current version of the MATLAB/Simulink based software. Key changes made for ALPHA v3.0 include the addition of new light- and medium-duty vehicle models to support simulation of electrified vehicle architectures (hybrid, plug-in hybrid, and battery electric vehicles) aligning with the automotive industry transition towards electrified fleets. Each electrified vehicle model was tuned to replicate operational behavior of components (such as engine
Many countries around the world are currently working toward carbon neutrality, which would reduce greenhouse gas emissions to net zero by 2050. To achieve carbon neutrality, the search for new fuels to replace gasoline has been active. This study focuses on hydrogen and methanol fuels and examines their effects on plain bearings when these fuels are used in internal combustion engines. Compared to gasoline, these fuels differ significantly in the composition of gases produced after combustion. It is assumed that nitric acid, etc. will be mixed in the engine oil when hydrogen is combusted whilst formic acid, etc. will be mixed in the engine oil when methanol fuel is combusted. For this reason, corrosion tests were conducted by adding nitric acid or formic acid solution to the engine oil then placing plain bearings in the deteriorated oil. The results confirmed that significant corrosion of the bismuth overlay coating occurred and subsequently the performance of plain bearings may
Off-highway vehicles, with their unique requirements of durability, high power, and torque density, are typically powered by diesel ignition internal combustion engines (ICEs). This reliance on ICEs significantly contributes to greenhouse gases (GHGs) emissions. For this reason, there is an urge to develop an energy-efficient powertrain architecture that produces fewer GHGs emissions while meeting the variable torque levels and variable speeds and performing various duty cycles with high efficiency. In order to select the energy-efficient powertrain architecture for the off-highway vehicle, different existing powertrain architectures (i.e., series hybrid, parallel hybrid, series-parallel hybrid, conventional) for off-highway applications have been studied to highlight their pros and cons. This is done considering the different duty cycles and applications along with Life Cycle Analysis (LCA). Off-highway vehicles operate under different road/surface conditions than on-road vehicles
Combining a low-carbon content fuel, such as natural gas, with a high-efficiency engine can reduce greenhouse gas emissions significantly in hard-to-electrify long-haul trucking applications. Turbo-compounding, where an additional power turbine is installed in the exhaust stream after the turbocharger turbine, can extract useful amounts of energy from diesel engine exhaust at high loads. This work assesses the net benefits of combining turbo-compounding with a high-efficiency, natural gas fuelled heavy-duty engine. The effects on brake specific fuel consumption (BSFC), greenhouse gas emissions, and engine-out emissions of nitrogen oxides (NOx) and methane (CH4) are considered. The experimentally validated 1D model for a 13L diesel pilot- direct injection of natural gas, heavy-duty engine in GT-SUITETM is used to develop a series turbo-compound model. The effects of turbine sizes and flow capacities in fixed-geometry turbocharging and power turbines are evaluated on the engine’s
The depletion of fossil fuels and the emergence of global warming propel public sectors to explore alternative energy such as renewable electricity and hydrogen to reduce greenhouse gas (GHG) emissions. Numerous studies have demonstrated substantial environmental benefits of electric light-duty vehicles. However, research focusing on heavy-duty vehicles is still relatively scarce, and the transition to zero emissions heavy-duty trucks is facing enormous technical and economic challenges. This work investigated GHG emissions during the manufacturing and assembly phase of heavy-duty vehicles (HDVs), including battery electric trucks (BETs) and gaseous hydrogen fuel cell electric trucks (FCETs) using SimaPro software package with wildly accepted Ecoinvent database based on UK grid mix scenarios. A comparative analysis of greenhouse gas (GHG) emissions during the production phase of 700 bar- and 350 bar-H2 FCETs and their battery electric counterparts (eqBETs) was conducted under two UK
The use of internal combustion engine vehicles (ICEVs) and hybrid electric vehicles (HEVs) powered by biofuels produced by photosynthetic fixation of CO2 and synthetic fuels produced by industrial synthetic reactions can be an effective way to reduce well-to-wheel (WtW) greenhouse gas (GHG) emissions intensity from vehicles, including both new and legacy fleet. In this study, several lower-carbon intensity fuels that contain at least 50% of renewable components, have at least 40% lower carbon intensity compared to commercially available E10 gasoline, and meet applicable US fuel standards were evaluated in a naturally aspirated (NA) engine in the legacy fleet, a turbocharged engine in the legacy fleet, and a prototype turbocharged super lean-burn engine, to identify their effects on thermal efficiency and exhaust emissions. As a result, it was confirmed that the lower-carbon intensity fuel can provide almost equivalent engine power and thermal efficiency as conventional fuel, and good
Electric trucks, due to their weight and payload, need a different layout than passenger electric vehicles (EVs). They require multiple motors or multi-speed transmissions, unlike passenger EVs that often use one motor or a single-speed transmission. This involves determining motor size, number of motors, gears, and gear ratios, complicated by the powertrain system’s nonlinearity. The paper proposes using a stochastic active learning approach (Bayesian optimization) to configure the motors and transmissions for optimal efficiency and performance. Backwards simulation is applied to determine the energy consumption and performance of the vehicle for a rapid simulation of different powertrain configurations. Bayesian optimization, was used to select the electric drive unit (EDU) design candidates for two driving scenarios, combined with a local optimization (dynamic programming) for torque split. By optimizing the electric motor and transmission gears, it is possible to reduce energy
Renewable Gasoline Blends can deliver greater than 50% reduction in vehicle Well-to-Wheel (WtW) greenhouse gas emissions when used in current vehicles. When paired with a state-of-the-art hybrid vehicle (relative to an average vehicle on U.S. roads today), a greater than 70% reduction in WtW emissions can be achieved. Importantly, Renewable Gasoline Blends can be formulated to align with existing market standards for gasoline, thereby functioning as a drop-in fuel solution compatible with all gasoline-powered vehicles. Renewable Gasoline Blends can also be formulated with higher ethanol blend ratios to meet a variety of fuel grades and market standards. These varying formulations can result in tradeoffs across engine performance, fuel economy, and potentially cost. For example, higher ethanol blends investigated lead to slight decreases in fuel economy across FTP, HWFE, and US06 cycles (typically ~1 - 2%, despite 2 – 5% lower heating values); however, significant decreases in PM
There is a need to reduce both the greenhouse gas emissions of internal combustion engines, and the reliance on traditional fossil fuels like Ultra Low Sulfur Diesel (ULSD). In this research, a synthetic paraffinic kerosene fuel, designated S8 and created from natural gas feedstocks using the Fischer-Tropsch process was investigated to determine its autoignition and combustion characteristics, emissions, and tribological properties. This fuel, S8, was found to have a Derived Cetane Number (DCN) of 62, which reflects a shorter Ignition Delay (ID), and Combustion Delay (CD) compared to ULSD, which has a DCN of 48. However, due to the chemical properties of S8, it lacks sufficient lubrication qualities in comparison to ULSD, so addition of 3% methyl oleate by mass was used to improve lubricity. The shorter ignition delay of S8, initially observed in a Constant Volume Combustion Chamber (CVCC) and confirmed in a fired Common Rail Direct Injection (CRDI) experimental engine. Investigations
In the United States (US), the off-road sector (i.e., agriculture, construction, etc.) contributes to approximately 10% of the country’s transportation greenhouse gas (GHG) emissions, similar to the aviation sector. The off-road sector is extremely diverse; as the EPA MOVES model classifies it into 11 sub-sectors, which include 85 different types of equipment. These equipment types have horsepower ranging from 1 to greater than 3000 and have very different utilization, which makes decarbonization a complex endeavor. To address this, Argonne’s on-road vehicle fleet model, VISION, has been expanded to the off-road sector. The GHG emission factors for several energy carriers (biofuels, electricity, and hydrogen) have been incorporated from Argonne’s GREET model for a sector-wide well-to-wheel (WTW) GHG emissions analysis of the present and future fleet. Several technology adoption and energy decarbonization scenarios were modeled to better understand the appropriate actions required to
This study addresses the challenges of electrifying heavy-duty vehicle fleets, particularly school buses, by focusing on the development of dedicated depot charging infrastructure and grid resilience. A key challenge is managing recharging limitations while considering grid resilience in the electrification of school bus fleets. Using real operational data, the study introduces a two-phase approach to optimize both charging infrastructure and scheduling. In the first phase, the optimal number of chargers is determined to ensure sustainable fleet operations. In the second phase, charging schedules are refined to reduce peak power demand and improve grid resilience. Experimental results demonstrate that approximately half the fleet size is required in chargers, with distributed charging and peak shaving strategies reducing peak power demand by 20% to nearly 45%. These findings offer practical insights for fleet managers, grid operators, and policymakers on enhancing grid resilience and
The transportation sector is responsible for a significant portion of greenhouse gas emissions. Within the sector, truck freight is responsible for a third of the associated emissions. Alternative powertrains are seen as a viable approach to significantly reduce these emissions. Prior to making a large-scale transition, it is important to consider the following questions: will the power grid support a transition to alternative powertrains?; will the transition truly reduce carbon emissions?; and will the transition impose an unnecessary economic burden on companies within the industry? The answer to these questions, however, can vary by geography, maturity/capacity of the energy distribution network or predicted vehicle load. We focus on the latter two questions, investigating the variation in estimated total cost of ownership and carbon emissions across the United States at the zip code level for both heavy-duty battery electric vehicles and heavy-duty fuel cell electric vehicles. As
This study looks into the impact of temperature on the aging of lithium-ion batteries, which are an important component of energy storage systems in electric vehicles. To evaluate battery capacity over time, experiments were carried out at two temperatures, 25°C and 50°C, imitating real-world vehicle circumstances. Pristine cells were initially assessed in terms of capacity and internal resistance. Aging results from cycling indicate that higher operating temperatures, particularly under aggressive conditions (fast charging), lead to accelerated battery degradation due to heat accumulation. Charging at 2C resulted in fast degradation at both temperatures, with the battery reaching its End Of Life (EOL), 80% capacity, in fewer than 200 cycles. Surprisingly, cycling at 50°C resulted in a longer lifespan than 25°C for 1C charge/discharge rates. The 1C charge and 2C discharge regimen at 50°C produced the best results, retaining more than 80% capacity even after 600 cycles. This shows that
Maritime transportation plays a vital role in the economy and is one of the most energy-efficient modes of transportation. However, it is a growing source of greenhouse gas emissions. A potential solution to lower carbon emissions from maritime transport is to use renewable fuels in marine engines. Hydrogen or methanol can serve as the primary energy source in internal combustion (IC) engines. However, their high autoignition temperatures require an external ignition source to start combustion in compression ignition (CI) engines. The Dual Fuel (DF) approach offers an effective method for incorporating these fuels. To accurately simulate dual fuel combustion, certain parameters need to be carefully addressed. One crucial parameter to investigate is estimating the flame entrainment area, as it directly affects the mass burning rate. In this work, a novel geometric approach is developed to estimate the evolution of the flame entrainment area. This model is integrated into a multi-zone
In order to reduce the environmental impact of transportation, the adoption of low and zero carbon fuel is needed to reduce the greenhouse gas emissions from engines, both from tailpipe and well-to-wheel perspectives. However, for some of the promising fuels, such as renewable natural gas and ammonia, the relatively low chemical reactivity and laminar flame speed bring challenge to a rapid and efficient combustion process, especially under lean or diluted conditions to suppress NOx emissions, leading to reduced combustion and thermal efficiencies. To tackle the challenge, high in-cylinder flow speed is needed to shorten the combustion duration, together with strong ignition sources to support the initial flame kernel development. In this paper, an ignition energy modulation system is developed to enhance both discharge current and discharge energy of a spark event to secure the ignition process. Moreover, a rapid compression machine is employed to compress the fuel-air mixture to the
With the global shift towards sustainable and low-emission transportation, hydrogen-fueled engines stand out as a promising alternative to traditional fossil fuels, offering significant potential to reduce greenhouse gas emissions. This study provides a comprehensive evaluation of the performance and emissions characteristics of a hydrogen-powered heavy-duty compression ignition engine, which has been modified to operate as a Spark Ignition (SI) engine with a high compression ratio of 17:1. The evaluation was conducted across various speeds, loads, and spark timings under ultra-lean combustion conditions. The analysis utilized a modified 6-cylinder, 13-liter Volvo D13 diesel engine, configured to operate in single-cylinder mode with the addition of a spark plug for SI operation. The study examined key performance metrics, including brake thermal efficiency (BTE), power output, and specific fuel consumption, under the selected operating conditions. Emissions profiles for nitrogen oxides
In 2022, the U.S. transportation sector was the largest source of greenhouse gas emissions in the country, with the combination of passenger and commercial vehicles contributing 80% of these emissions. As adoption of passenger electric vehicles continues to climb, sights are being set on the electrification of heavy-duty commercial vehicle (HDCV) fleets. The sustainability of these shifts relies in part on the addition of significant renewable energy generation resources to both bolster the grid in the face of increased demand, and to prevent a shift in the source of greenhouse gas (GHG) emissions to the grid, as opposed to a true net reduction. Additionally, it is necessary to quantify the variations in economic viability across the country for these technologies as it pertains to their productive capabilities. Doing so will encourage investment and ensure that the transition to electrified HDCV fleets is commercially viable, as well as sustainable. In an effort to meet these goals
Electric vehicles (EVs) represent a significant stride toward environmental sustainability, offering a multitude of benefits such as the reduction of greenhouse gas emissions and air pollution. Moreover, EVs play a pivotal role in enhancing energy efficiency and mitigating reliance on fossil fuels, which has propelled their global sales to unprecedented heights over the past decade. Therefore, choosing the right electric drive becomes crucially important. The main objective of this article is to compare various conventional and non-conventional electric drives for electric propulsion in terms of electromechanical energy conversion ratio and the thermal response under continuous [at 12 A/mm2 and 6000 rpm] and peak [at 25 A/mm2 and 4000 rpm] operating conditions. The comparative analysis encompasses torque density, power density, torque pulsation, weight, peak and running efficiencies of motor, inverter and traction drive, electromechanical efficiency, and active material cost. This
The growing number of automobiles on the road has raised awareness about environmental sustainability and transportation alternatives, sparking ideas about future transportation. Few short-term alternatives meet consumer needs and enable mass production. Because they do not accurately reflect real-world driving. Current models are unable to estimate vehicle emissions. However, the purpose of this research is to present an application of an adaptive neuro-fuzzy inference system for managing the various factors contributing to vehicle gasoline engine exhaust emissions. It examines how well the three known standardized driving cycles (DSCs). Accurately reflect real-world driving and evaluate the impact of real-world driving on vehicle emissions. Indirect emissions are inversely proportional to the vehicle’s fuel consumption. The methodology used is Eco-score methodology to calculate indirect emissions of light vehicles. Expected emission charge estimates for different using styles
Active fuel injection into a pre-chamber (PC) promotes high-temperature and highly turbulent jets, which ignite the cylinder gas with a very high exhaust gas recirculation (EGR) ratio, reducing emissions such as NOx. In the present study, two active PC injection strategies were designed to investigate the effect of injected hydrogen mass and PC mixture air-to-fuel equivalence ratio λ on PC combustion, jet formation, and main chamber (MC) combustion. Stoichiometric or rich hydrogen/oxygen mixtures are actively injected into the PC to enhance the combustion processes in the PC and the MC. A three-dimensional numerical engine model is developed using the commercial CFD code CONVERGE. The engine geometry and parameters adopt a modified GM 4-cylinder 2.0 L GDI gasoline engine. The local developments of gas temperature and velocity are resolved with the adaptive mesh refinement (AMR). The turbulence of the flow is computed with the k-epsilon model of the Reynolds-averaged Navier–Stokes (RANS
Environmental awareness is being fostered in every sector, with particular emphasis on the automotive industry. Conventional internal combustion engines are responsible for greenhouse gas emissions and health issues. Researchers are looking for alternative technologies to reduce carbon footprint and for a green environment. In this study, electric drivetrain is designed for 20% range extension and retrofitted in conventional two-wheeler. An effective control technique has been developed, thoroughly tested, and effectively implemented on the two-wheeler. The hybrid drivetrain architecture is assessed for complexities such as the required space for the battery and the location for fitting the electric motor. During low-speed conditions, the electric motor reduced the emissions and minimized fuel consumption. Consequently, the overall utilization of internal combustion engines at low-speed conditions has decreased, leading to a decrease in the vehicle's fuel consumption and exhaust gases.
Biomass fuels, such as sawdust and groundnut shells, are increasingly recognized as sustainable alternatives to fossil fuels. However, their high moisture content and loose structure result in low thermal efficiency. To improve performance, pellet forms of these fuels are often used. Naturally available raw and pellet forms of Sawdust, groundnut shell fuels have been utilized in this study. This study evaluates and compares the thermal efficiency of a gasifier cook stove and emissions from the combustion of raw and pellet forms of biomass fuels. It was found that the burning rate and firepower increase significantly with the use of pellet from of fuels. Sawdust pellets exhibited a highest thermal efficiency of 22.41%. The hydrocarbon (HC) levels for groundnut shell pellets were observed to range between 1 and 5 parts per million (ppm), while for sawdust pellets, it was observed to range from 1 to 6 ppm, indicating the preferable usage of pellets as fuel over raw form of biomass fuel.
Considered as one of the most promising technology pathways for the transport sector to realize the target of “carbon neutral,” fuel cell vehicles have been seriously discussed in terms of its potential for alleviating environmental burden. Focused on cradle-to-gate (CtG) stage, this article evaluates the environmental impacts of fuel cell heavy-duty vehicles of three size classes and three driving ranges to find the critical components and manufacturing processes in the energy context of China. The findings show that the greenhouse gas (GHG) emissions of the investigated fuel cell heavy-duty vehicle range from 47 ton CO2-eq to 162 ton CO2-eq, with the fuel cell system and hydrogen storage system collectively contributing to 37%–56% of the total. Notably, as the driving range increases, the proportion of GHG emissions stemming from fuel cell-related components also rises. Within the fuel cell system, the catalyst layer and bipolar plate are identified as the components with the most
With the adoption of the IMO Greenhouse Gas Emission Reduction Strategy Revision, the international shipping industry is facing huge pressure to reduce greenhouse gas emissions, and the conversion of ship power from traditional fossil fuels to low-carbon and zero-carbon fuels is the fundamental solution, and ammonia fuel, as a zero-carbon fuel, is an important direction for the development of ship power in the future. Based on a marine low-speed diesel engine with a bore of 520 mm, computational fluid dynamics (CFD) numerical simulation was carried out to study the effects of different diesel energy fractions, ammonia injection pressure, ammonia injection timing and ammonia diesel injection interval on the combustion and emission characteristics of the engine under the dual-fuel combustion mode of high-pressure dual direct injection. The calculation results show that under the condition of the current engine, 5% of diesel energy can reduce carbon emissions by 92.8% under the premise of
In the context of low-carbon and zero-carbon development strategies, the transformation and upgrading of the energy structure is an inevitable trend. As a renewable fuel, ammonia has a high energy density. When ammonia is burned alone, the combustion speed is slow. The emissions of nitrogen oxides and unburned ammonia is high. Therefore, a suitable high-reactivity combustion aid fuel is required to improve the combustion characteristics of ammonia. Based on this background, this study converted a six-cylinder engine into a single-cylinder ammonia/diesel dual-fuel system, with diesel fuel as the base and a certain percentage of ammonia blended in. The impact of varying the injection pressure and equivalence ratio on engine combustion and emissions was examined. The results demonstrate that an appropriate increase in injection pressure can promote fuel-gas mixing and increase the indicated thermal efficiency (ITE). With regard to emissions, an increase in injection pressure has been
Under the guidance of carbon neutrality goals, ammonia is expected to become a promising alternative fuel for internal combustion engines. Ammonia-diesel dual-fuel combustion not only effectively reduces carbon emissions but also addresses the issue of ammonia's slow combustion speed, ensuring good engine performance. Ammonia-diesel engines with liquid ammonia direct injection have the potential to further increase the ammonia energy ratio (AER) and reduce unburned ammonia, greenhouse gas (GHG) emissions, as well as NOx emissions. Based on a numerical model of a liquid ammonia direct injection ammonia-diesel engine, this paper compares two different injection system configurations: coaxial and non-coaxial liquid ammonia direct injection, and investigates the effect of AER on combustion and emission characteristics in the non-coaxial mode. The results show that, compared to the non-coaxial mode, the coaxial mode achieves more even fuel distribution and combustion distribution, higher
ERRATUM
With the extensive production and widespread use of plastics, the issue of environmental pollution caused by plastic waste has become increasingly prominent. Consequently, researchers have been focusing on developing efficient methodologies for upcycling waste plastics and converting them into value-added materials. This hybrid review–conceptual article first provides an overview of strategies for upcycling waste plastic into carbon-capturing materials. It presents carbonization and activation as key steps in converting plastic waste into adsorbent materials and explores strategies for converting common waste plastics. Building upon this foundation, the article introduces and conceptualizes a novel upcycling approach with two manufacturing routes to convert plastic waste into carbon-capturing materials using supercritical fluid (ScF)-assisted injection molding process. It continues by investigating the potential of developing lightweight components made of such carbon-capturing
The transition from internal combustion engine (ICE) industry to electric vehicle (EV) industry has significant financial implications for both the automotive industry, government, and associated partners. The shift to EVs could lead to savings in foreign exchange reserves, the creation of new jobs, and a reduction in greenhouse gas emissions. However, the transition could also result in job losses in the automobile and its associated manufacturing industry. This study aims to analyze the impact of this transition on different stakeholders in India. The study takes into account the different financial aspects that includes production, technology, government policy, skilling, employability, job creation, and other associated aspects on Indian economy. For the projected study different cases were considered with 2030 as the projected year with 30% EVs. A modest attempt is made to analyze the impact on associated partners. The findings of the study suggest that the transition to EVs could
Letter from the Focus Issue Editors
The aim of this study is to compare possible approaches that support the goal of achieving a carbon-neutral society in the mobility sector, with a specific focus on the two-wheel segment of the mobility sector. One of the key considerations in the mobility sector is the transition from a fossil fuel-based energy mix to a more renewable one. While there are numerous options available for achieving a carbon-neutral society in the four-wheel scenario, the two-wheel sector presents a different challenge due to a smaller number of available options. This study introduces a new comparison between full electric, gasoline, and ethanol-powered two-wheeled vehicles. It suggests that ethanol is a feasible solution for reducing carbon emissions in the two-wheel sector. The study includes an analysis of CO2 emissions for two-wheel vehicles using a life cycle approach, focusing on the technologies of full electric motorcycles, motorcycles with flex-fuel internal combustion engines running on
Mobility in Brazil, dominated by road transportation, is responsible for consuming around a third of the energy matrix and for emitting approximately half of the energy-related emissions in the country. Among the alternatives to reduce its greenhouse gas emissions, the use of low-carbon hydrogen has a strong potential for decarbonization and improvement of engine efficiency. Thus, this study experimentally investigated the partial replacement of commercial diesel (with 12% of fatty acids methyl esters (FAME) biodiesel) by hydrogen in a commercial vehicle equipped with a compression-ignition internal combustion engine. To investigate the effects of this substitution on performance and emission profile, the vehicles was adapted for dual-fuel operation and hydrogen was injected together with air into the MB OM 924 LA engine of a Mercedes-Benz Accelo 1016 vehicle. Tests were carried out on a chassis dynamometer with 0%, 2% and 4% slope and at speeds equal to 50, 60 and 70 km/h to simulate
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