Search Results (10)

The paper discusses potential hazards at hydrogen refueling stations for transportation vehicles: cars and trucks. The main hazard analyzed here is an uncontrolled gas release due to a failure in one of the structures in the station: storage tanks of different pressure levels or a dispenser. This may lead to a hydrogen cloud occurring near the source of the release or at a given distance. The range of the cloud was analyzed in connection to the amount of the released gas and the wind velocity. The results of the calculations were compared for chosen structures in the station. Then potential fires and explosions were investigated. The hazard zones were calculated with respect to heat fluxes generated in the fires and the overpressure generated in explosions. The maximum ranges of these zones vary from about 14 to 30 m and from about 9 to 14 m for a fires and an explosions of hydrogen, respectively. Finally, human death probabilities are presented as functions of the distance from the sources of the uncontrolled hydrogen releases. These are shown for different amounts and pressures of the released gas. In addition, the risk of human death is determined along with the area, where it reaches the highest value in the whole station. The risk of human death in this area is 1.63 × 10⁻⁵ [1/year]. The area is approximately 8 square meters. Full article

As the country that emits the most carbon in the world, China needs significant and urgent changes in carbon emission control in the transportation sector in order to achieve the goals of reaching peak carbon emissions before 2030 and achieving carbon neutrality by 2060. Therefore, the promotion of new energy vehicles has become the key factor to achieve these two objectives. For the reason that the comprehensive transportation cost directly affects the end customer’s choice of heavy truck models, this work compares the advantages, disadvantages, and economic feasibility of diesel, liquefied natural gas (LNG), electric, hydrogen, and methanol heavy trucks from a total life cycle cost and end-user perspective under various scenarios. The study results show that when the prices of diesel, LNG, electricity, and methanol fuels are at their highest, and the price of hydrogen is 35 CNY/kg, the total life cycle cost of the five types of heavy trucks from highest to lowest are hydrogen heavy trucks (HHT), methanol heavy trucks (MHT), diesel heavy trucks (DHT), electric heavy trucks (EHT), and LNG heavy trucks (LNGHT), ignoring the adverse effects of cold environments on car batteries. When the prices of diesel, LNG, electricity, and methanol fuels are at average or lowest levels, and the price of hydrogen is 30 CNY/kg or 25 CNY/kg, the life cycle cost of the five heavy trucks from highest to lowest are HHT, DHT, MHT, EHT, and LNGHT. When considering the impact of cold environments, even with lower electricity prices, EHT struggle to be economical when LNG prices are low. If the electricity price is above 1 CNY/kWh, regardless of the impact of cold environments, the economic viability of EHT is lower than that of HHT with a purchase cost of 500,000 CNY and a hydrogen price of 25 CNY/kg. Simultaneously, an exhaustive competitiveness analysis of heavy trucks powered by diverse energy sources highlights the specific categories of heavy trucks that ought to be prioritized for development during various periods and the challenges they confront. Finally, based on the analysis results and future development trends, the corresponding policy recommendations are proposed to facilitate high decarbonization in the transportation sector. Full article

Refuelling hydrogen-powered cars, buses, trucks, trains, ships, and planes is a technological challenge. The absence of contemporary CFD models of refuelling through the entire hydrogen refuelling station (HRS) equipment is one of the scientific bottlenecks. Detailed refuelling protocols for more than 10 kg of hydrogen, e.g., for heavy-duty vehicles, are absent. A thoroughly validated CFD model for simulations of the refuelling process through the entire equipment of the HRS is needed for protocols’ development. This study aims to numerically simulate the start-up phase of the refuelling procedure at HRS using the developed CFD model. The simulations through the entire HRS equipment are compared against unique experimental data of NREL and demonstrated agreement with measured pressure and temperature dynamics in onboard storage tanks during the start-up phase while having less than 5% deviation. The CFD model demonstrates excellent predictive capability and is time efficient. The simulation time of the start-up phase of 14 s duration is about 2 h on a 32-core CPU. Full article

Transformation of European transport belongs among the key challenges to achieve a reduction of 55% by 2030 and climate neutrality by 2050. This study focuses on GHG emissions in road transport in Slovakia, as it currently accounts for 19% of total GHG emissions (road transport emissions account for 99% of transport emissions). The main driver for this study was the preparation of Slovakia’s Climate Act and investigation of where are the limits of greenhouse gas emission reduction by 2050. With the aim of achieving maximum reduction in emissions by 2050 compared to 2005 levels, various scenarios were developed using the COPERT model to explore emission reduction strategies. The scenarios considered different subsectors of road transport, including passenger cars, light-commercial vehicles, heavy-duty vehicles (buses and trucks), and L-category vehicles and examined encompassed reduction of transport demand, improving energy efficiency, and utilizing advanced technologies with alternative fuels (hybrids, PHEV, CNG, LNG or LPG). However, the economic aspects of specific mitigation options were not considered in this analysis. The results show that there is a possibility of 77% GHG emission reduction by 2050 in comparison with the 2005 level. This reduction is accompanied by a shift in vehicle technologies to alternative fuels like electricity, hydrogen, and to a smaller extent biofuels and biomethane. This study shows that it will be possible to achieve 86.7% zero-emission cars and an additional 12.9% low emission and alternative fueled cars by 2050. By identifying and assessing these scenarios, policymakers and stakeholders can gain insights into the possibilities, challenges, and potential solutions for meeting the climate targets set by the European Union’s Fit for 55 climate package. Full article

The negative consequences of toxic emissions from internal combustion engines, energy security, climate change, and energy costs have led to a growing demand for clean power sources in the automotive industry. The development of eco-friendly vehicle technologies, such as electric and hydrogen vehicles, has increased. This article investigates whether hydrogen vehicles will replace electric vehicles in the future. The results showed that fuel-cell cars are unlikely to compete with electric cars. This is due to the advancements in electric vehicles and charging infrastructure, which are becoming more cost-effective and efficient. Additionally, the technical progress in battery electric vehicles (BEVs) is expected to reduce the market share of fuel-cell electric vehicles (FCEVs) in passenger vehicles. However, significant investments have been made in hydrogen cars. Many ongoing investments seem to follow the sunk cost fallacy, where decision-makers continue to invest in an unprofitable project due to their already invested resources. Furthermore, even with megawatt charging, fuel-cell trucks cost more than battery-powered electric trucks. The use cases for fuel-cell electric trucks are also much more limited, as their running expenses are higher compared to electric cars. Hydrogen vehicles may be beneficial for heavy transport in remote areas. However, it remains to be seen if niche markets are large enough to support fuel-cell electric truck commercialization and economies of scale. In summary, we believe that hydrogen vehicles will not replace electric cars and trucks, at least before 2050. Full article

Many countries are immersed in several strategies to reduce the carbon dioxide (CO₂) emissions of internal combustion engines. One option is the substitution of these engines by electric and/or hydrogen engines. However, apart from the strategic and logistical difficulties associated with this change, the application of electric or hydrogen engines in heavy transport, e.g., trucks, shipping, and aircrafts, also presents technological difficulties in the short-medium term. In addition, the replacement of the current car fleet will take decades. This is why the use of biofuels is presented as the only viable alternative to diminishing CO₂ emissions in the very near future. Nowadays, it is assumed that vegetable oils will be the main raw material for replacing fossil fuels in diesel engines. In this context, it has also been assumed that the reduction in the viscosity of straight vegetable oils (SVO) must be performed through a transesterification reaction with methanol in order to obtain the mixture of fatty acid methyl esters (FAMEs) that constitute biodiesel. Nevertheless, the complexity in the industrial production of this biofuel, mainly due to the costs of eliminating the glycerol produced, has caused a significant delay in the energy transition. For this reason, several advanced biofuels that avoid the glycerol production and exhibit similar properties to fossil diesel have been developed. In this way, “green diesels” have emerged as products of different processes, such as the cracking or pyrolysis of vegetable oil, as well as catalytic (hydro)cracking. In addition, some biodiesel-like biofuels, such as Gliperol (DMC-Biod) or Ecodiesel, as well as straight vegetable oils, in blends with plant-based sources with low viscosity have been described as renewable biofuels capable of performing in combustion ignition engines. After evaluating the research carried out in the last decades, it can be concluded that green diesel and biodiesel-like biofuels could constitute the main alternative to addressing the energy transition, although green diesel will be the principal option in aviation fuel. Full article

While the electrification of passenger vehicles is in full swing, for the decarbonization of heavy-duty trucks still various challenges exist. Especially the high energy consumption in combination with high daily driving ranges makes battery electric operation much more difficult than for passenger cars. Accordingly, a broad set of different drivetrains is discussed, inter alia hydrogen trucks, catenary hybrid trucks and synthetic fuels. One main advantage of the direct use of electricity in trucks is the high energy efficiency. Still, for heavy duty trucks different concepts for electrification do exist. Here, we compare battery electric trucks with a fast charging option, full electric catenary trucks and battery swap trucks. For a broad perspective, we use seven different comparative dimensions ranging from total cost of ownership to more qualitative but not less important aspects such as necessity of standardization, which would reduce manufacturer’s decision-making freedom. We base our comparison on findings from German pilot projects. While battery electric trucks or battery swap are advantageous since they can be operated in niche operations and thus allow a demand driven rollout of charging infrastructure, catenary infrastructure needs high investments upfront which entails financial risks, but allows for lowest cost if utilized to capacity. Full article

Due to environmental pollution and depletion of fossil fuels, hydrogen is becoming an increasingly practical, clean and environmentally friendly option for transportation and energy storage among all green alternative energy sources introduced. Hydrogen storage and delivery is expensive because of the lower energy density per unit volume as compared with conventional fossil fuels. Hence, hydrogen is usually stored in a gaseous state and delivered via tube trailers or pipelines. In this study, a transient structural analysis of a skid structure mounted on a hydrogen tube trailer was performed under shock load induced by road irregularities. The dynamics of the driving trailer according to the unevenness of the road surface were obtained through multibody dynamic simulations considering the full car model equipped with 64 hydrogen tubes. The transient structural analysis of the tube skid was performed by considering the resulting acceleration values as constraints. Through the sequential simulations, we evaluated the structural safety of the designed tube skid mounted on a trailer during hydrogen transport. Full article

The aim of this publication is to review the current state and possibilities of developing electromobility and alternative fuels in Poland. It was found that the current market for alternative fuels in Poland is insufficiently developed. At the end of 2019 in Poland, liquefied petroleum gas-powered cars accounted for approximately 3.3 million pieces, which amounts to 14.3% all passenger vehicles up to 3.5 tonnes of gross vehicle weight. There were over 9000 electric cars on the road, the share of which accounted for 0.04% of domestic passenger transport. The lack of a sufficient number of charging points, inhibiting the development of electromobility, was also noted. There were approximately 4000 (0.02%) passenger cars powered by compressed natural gas. Liquefied gas-powered vehicles were exclusively public transport vehicles or trucks. The share of biofuels in the Polish transport sector stands at 4%, while European Union requirements are at a level of 10%. Although there is huge potential for the use of hydrogen as an alternative to conventional transport fuels in Poland, just one hydrogen-powered vehicle has been registered in the country so far, with no filling station in existence for this fuel. The synthetic fuel sector is in the planning stage. Full article

The technological lock-in of the transportation and industrial sector can be largely attributed to the limited availability of alternative fuel infrastructures. Herein, a countrywide supply chain analysis of Germany, spanning until 2050, is applied to investigate promising infrastructure development pathways and associated hydrogen distribution costs for each analyzed hydrogen market. Analyzed supply chain pathways include seasonal storage to balance fluctuating renewable power generation with necessary purification, as well as trailer- and pipeline-based hydrogen delivery. The analysis encompasses green hydrogen feedstock in the chemical industry and fuel cell-based mobility applications, such as local buses, non-electrified regional trains, material handling vehicles, and trucks, as well as passenger cars. Our results indicate that the utilization of low-cost, long-term storage and improved refueling station utilization have the highest impact during the market introduction phase. We find that public transport and captive fleets offer a cost-efficient countrywide renewable hydrogen supply roll-out option. Furthermore, we show that, at comparable effective carbon tax resulting from the current energy tax rates in Germany, hydrogen is cost-competitive in the transportation sector by the year 2025. Moreover, we show that sector-specific CO₂ taxes are required to provide a cost-competitive green hydrogen supply in both the transportation and industrial sectors. Full article