Hydrogen Transport Research Articles

Hydrogen supply chain for future hydrogen-fuelled railway in the UK: Transport sector focused

Though being attractive on railway decarbonisation for regional lines, excessive cost caused by immature hydrogen supply chain is one of the significant hurdles for promoting hydrogen traction to rolling stocks. Therefore, we conduct bespoke research on the UK's hydrogen supply chain for railway, concentrating on hydrogen transportation. Firstly, a map for the planned hydrogen production plants and potential hydrogen lines is developed with the location, capacity, and usage. A spatially explicit model for the hydrogen supply chain is then introduced, which optimises the existing grid-based methodology on accuracy and applicability. Compressed hydrogen at three pressures, and liquid hydrogen are considered as the mediums, incorporating by road and rail transport. Furthermore, three scenarios for hydrogen rail penetration are simulated respectively to discuss the levelised cost and the most suitable national transport network. The results show that the developed model with mix-integer linear programming (MILP) can well design the UK's hydrogen distribution for railway traction. Moreover, the hydrogen transport medium and vehicle should adjust to suit for different era where the penetration of hydrogen traction varies. The levelised cost of hydrogen (LCOH) decreases from 6.13 £/kg to 5.13 £/kg on average from the conservative scenario to the radical scenario. Applying different transport combinations according to the specific situation can satisfy the demand while reducing cost for multi-supplier and multi-targeting hydrogen transport.

Assessment of the performance of implementation of renewable energy facilities with the prospect of hydrogen production using the example of southern Russia

Adopting experience and best practices for stimulating the development of RES in individual regions that most successfully implement RES-based installations into their energy balance is a necessary element in the development of the energy sector of disadvantaged regions, while a methodology is needed to determine what factors influenced the success of implementation and what criteria should be used to compare and to determine the success of the implementation of RES in the region, however, a generally accepted methodology has not been formed to date. It was proposed to determine the leading regions and disadvantaged regions from the point of view of success in introducing renewable energy sources into the regional energy system based on the success of fulfilling the regional demand. To assess the success of the use and implementation of installations based on renewable energy in the regional energy system, it is necessary to identify parameters that reflect the potential of renewable energy sources, the initial state of energy supply in the region, the costs of construction of the installation, the profit received from the sale of generated energy, and the current state of the regional energy system. Based on the developed technique, the six most energy-intensive regions included in the operating area of the Southern Branch of United Dispatch Control Center of Russian Power System Operator which have renewable energy power plants were analyzed. The chosen indicator was the share of energy resources generated from renewable energy sources in the total amount of energy resources. Based on the results of the analysis, recommendations were drawn for disadvantaged regions. Energy donation for disadvantaged areas is proposed through the production of a universal energy carrier - hydrogen - in prosperous areas. For energy storage, hydrogen cryogenic storage facilities have been considered promising. The standard cryogenic hydrogen tank RSV-1400 was adopted as part of the main element of the hydrogen storage facility. The capacity of such tanks is 1 000 000 L. To transport energy to consumers, the possibilities of transporting hydrogen by cryogenic tankers and hydrogen transport tanks have been considered.In addition, at present there is a fairly large scientific, technical and practical base for the creation of gas and cryogenic liquid hydrogen pipelines.

A data-driven probabilistic evaluation method of hydrogen fuel cell vehicles hosting capacity for integrated hydrogen-electricity network

The growing demand for hydrogen in hydrogen fuel cell vehicles (HFCVs) will present challenges for the safe operation of the integrated distributed hydrogen supply network (DHSN) and power distribution network (PDN). This paper proposes a data-driven probabilistic evaluation method for determining the hosting capacity of hydrogen fuel cell vehicles (HVHC). Firstly, a directional mapping method is proposed to model the maximum safety boundaries of critical electrolyzers. It integrates the thermal-electrical and dynamic operating characteristics while maintaining the full boundaries in dimension reduction to ensure accuracy and efficiency. A probabilistic HVHC evaluation model is developed to consider uncertain factors of high dimensions despite data deficiency, such as HFCV refueling demand and renewable power. The proposed model determines the maximum network tolerance for the HFCV number, constrained by the safety constraints of the PDN integrated with DHSN, on-site and off-site hydrogen supplies coupled by tube trailers. Finally, a cross-term decoupled data-driven polynomial chaos expansion is proposed to efficiently solve the developed probabilistic HVHC model. It is established based on raw and small samples without extracted probability distribution information. The solution approach also combines the cross-terms in expansions using Taylor expansion, making it efficient for high-dimensional problems. Furthermore, the accuracy and scale reduction effect of the solution algorithm are proven based on Wasserstein ambiguity sets. Numerical studies on three systems show that the proposed method has only a 0.01% error in HVHC results and an 8.38% computation time of the Monte Carlo method.

Experimental and numerical studies on hydrogen leakage and dispersion in underground parking garages: Impact of leakage direction on safety considerations

Hydrogen leakage in confined spaces poses significant safety risks in hydrogen energy applications, potentially leading to fires and explosions. This paper focuses on the accident scene of hydrogen leakage and dispersion in underground parking garages. A medium-scale model (1/10) of an underground parking garage is designed and built to study the characteristics of the dispersion of hydrogen leaked from hydrogen fuel cell vehicles (HFCVs) in underground garages using experimental and numerical simulation methods. This paper focused on analyzing the dispersion characteristics of hydrogen leaked from hydrogen fuel cell vehicles (HFCVs) within these environments, with particular attention given to the influence of leakage direction—upward, horizontal, and downward—on hydrogen concentration distribution over space and time. For instance, it was observed that under equivalent flow rates, upward leakage tends to result in higher hydrogen concentrations at the leakage site. Conversely, downward leakage promotes wider hydrogen diffusion around the source, particularly evident at higher flow rates. Horizontal leakage, comparatively, exhibits lower risk due to greater air volume absorption. Complementing the experimental data, numerical simulations revealed consistent patterns in hydrogen diffusion. Specifically, the simulations illustrated a cyclic accumulation-diffusion-accumulation process. Notably, vertical upward leakage demonstrated the largest volume of regions exceeding a 4 % hydrogen volume fraction, whereas vertical downward leakage resulted in the greatest volume of regions surpassing an 18.3 % hydrogen volume fraction. This disparity arises from hydrogen accumulation beneath the vehicle in cases of vertical downward leakage. Conversely, regions of high concentration induced by horizontal leakage were the smallest. The study offers valuable insights for the design and construction of HFCVs and parking facilities, providing a theoretical framework for enhancing safety measures.

Risk-averse energy dispatch for hybrid energy refueling stations considering Boundedly rational mixed user equilibrium and operational uncertainties

Nowadays, charging stations, hydrogen refueling stations, and natural gas refueling stations are being integrated into hybrid energy refueling stations (HERSs) to save investment costs and offer diverse refueling services altogether. This research proposes a risk-averse energy dispatch strategy for HERSs, incorporating bounded user rationality and operational uncertainties. A boundedly rational mixed user equilibrium model is proposed to capture the mobility of heterogeneous traffic flow, including electric vehicles (EVs), hydrogen fuel cell vehicles (HFCVs), and natural gas vehicles (NGVs), each with distinct refueling demands characterized by bounded decision-making rationality. A grid-connected HERS model integrated with carbon capture and storage and on-site renewable energy sources is designed to provide sustainable refueling services to EVs, HFCVs, and NGVs. Furthermore, an HERS operator aggregates multiple HERSs to participate in the day-ahead and real-time electricity markets. The optimal equipment operation and energy bidding strategies for the HERS operator are solved using a risk-averse approach based on conditional value-at-risk, addressing operational uncertainties from heterogeneous refueling demand, electricity markets, and renewable generation. Numerical results have validated the effectiveness of the proposed method in promoting net-zero emissions, securing economic benefits, and mitigating risks associated with operational uncertainties.

Energy‐Efficient Hydrogen Liquefaction Process with Ortho‐Para Conversion and Boil‐Off Gas Recovery

AbstractHydrogen liquefaction is essential for the efficient storage and transportation of hydrogen. In the liquefaction process, catalytic ortho‐para conversion is crucial to achieve a product with at least 95 % para‐hydrogen to reduce boil‐off losses. The proposed hydrogen liquefaction process using a catalyst‐filled heat exchanger for continuous ortho‐para conversion is modeled through steady‐state thermal simulations in Aspen HYSYS. Additionally, an ejector is integrated to reliquefy boil‐off gas. The proposed design achieves a specific energy consumption (SEC) of 10.50 kWh ()−1 and an exergy efficiency (EXE) of 30.1 %, which is 18 % lower in SEC compared to processes with separate converters. The integrated approach enhances energy utilization and offers references for future hydrogen liquefiers.

Development of a practical formate/bicarbonate energy system

Liquid (organic) hydrogen carriers ([18H]-dibenzyltoluene, MeOH, formic acid, etc.) form a toolbox for the storage and transport of green hydrogen, which is crucial for the implementation of renewable energy technologies. Simple organic salts have been scarcely investigated for this purpose, despite many advantages such as low cost and minor toxicity, as well as easy handling. Here, we present a potassium formate/potassium bicarbonate hydrogen storage and release energy system, that is applicable and shows high stability (6 months). Utilizing ppm amounts of the molecularly defined Ru-5 complex, hydrogen release rates of up to 9.3 L h−1 were achieved. The same catalyst system promoted the hydrogenation of KHCO3 to HCOOK with a TON of 9650. In this way, combined hydrogen storage-release cycles can be performed for 40 times.

Comprehensive analysis of polysulfone membrane humidifier in hydrogen fuel cell vehicles: Experimental and theoretical approaches

This study performed a comprehensive experimental and theoretical analysis of a shell-and-tube type gas-to-gas humidifier module in a 95 kW class hydrogen fuel cell vehicle. The humidifier module features a polysulfone hollow fiber membrane characterized by its hydrophilic and non-fluorinated properties. Experimental investigations were conducted to understand the impacts of the inlet temperature, relative humidity, and temperature differences on heat and mass transfer rates, and the approach dew point temperature (ADT). The results showed that the ADT increased from 12.42 to 15.89 °C with a temperature difference of 15 °C between the shell and tube inlet sides, as the flow rate increased from 1000 to 3400 L/min, with the highest performance observed at lower flow rates. Simultaneously, a detailed theoretical model was developed, incorporating a new dual-mode sorption approach that accounts for temperature dependency within the solution-diffusion mechanism across the membrane. The developed model was in good agreement with the experimental results, with a relative error of less than 5 %. Furthermore, the dynamic model accurately predicts the response of the humidifier module to step changes in feed flow rates, simulating load variations in the fuel cell vehicle. This provides valuable insights into the humidifier's adaptability and responsiveness, which are crucial for optimizing its performance under various operating conditions.

Revolution in Renewables: Integration of Green Hydrogen for a Sustainable Future

In recent years, global efforts towards a future with sustainable energy have intensified the development of renewable energy sources (RESs) such as offshore wind, solar photovoltaics (PVs), hydro, and geothermal. Concurrently, green hydrogen, produced via water electrolysis using these RESs, has been recognized as a promising solution to decarbonizing traditionally hard-to-abate sectors. Furthermore, hydrogen storage provides a long-duration energy storage approach to managing the intermittency of RESs, which ensures a reliable and stable electricity supply and supports electric grid operations with ancillary services like frequency and voltage regulation. Despite significant progress, the hydrogen economy remains nascent, with ongoing developments and persistent uncertainties in economic, technological, and regulatory aspects. This paper provides a comprehensive review of the green hydrogen value chain, encompassing production, transportation logistics, storage methodologies, and end-use applications, while identifying key research gaps. Particular emphasis is placed on the integration of green hydrogen into both grid-connected and islanded systems, with a focus on operational strategies to enhance grid resilience and efficiency over both the long and short terms. Moreover, this paper draws on global case studies from pioneering green hydrogen projects to inform strategies that can accelerate the adoption and large-scale deployment of green hydrogen technologies across diverse sectors and geographies.

Toluene-Poisoning-Resistant High-Entropy Non-Noble Metal Anode for Direct One-Step Hydrogenation of Toluene to Methylcyclohexane.

The direct one-step hydrogenation of toluene to methylcyclohexane facilitated by a proton-exchange membrane water electrolyzer driven by renewable energy has garnered considerable attention for stable hydrogen storage and safe hydrogen transportation. However, a persistent challenge lies in the crossover of toluene from the cathode to the anode chamber, which deteriorates the anode and decreases its energy efficiency and lifetime. To address this challenge, the catalyst-poisoning mechanism is systematically investigated using IrO2 and high-entropic non-noble-metal alloys as anodes in acidic electrolytes saturated with toluene and toluene-oxidized derivatives, such as benzaldehyde, benzyl alcohol, and benzoic acid. Benzoic acid plays an important role in polymer-like carbon-film formation by blocking the catalytically active sites on the anode surface. Moreover, Nb and the highly entropic state on the surface of the multi-element alloy lower the adsorbing ability of toluene and prevent polymer-like carbon film formation. This study contributes to the design of catalyst-poisoning-resistant anodes for organic hydride technology, advanced fuel cells, and batteries.

A Review of Hydrogen Storage and Transportation: Progresses and Challenges

A Review of Hydrogen Storage and Transportation: Progresses and Challenges

Influence of crystallographic textures on the hydrogen embrittlement resistance of austenitic stainless steel

Hydrogen embrittlement (HE) resistance is a significant concern in austenitic stainless steel (ASS) used for hydrogen transportation and storage. While microstructure-controlled methods to enhance HE resistance have been extensively studied in ferritic steels, comprehensive research on microstructure effects in ASS is lacking. In this study, two 316L ASSs with different microstructures were evaluated for HE resistance using electrochemical hydrogen charging. The steel with abundant in <111>+<110> orientations showed a significant elongation reduction after hydrogen charging. It revealed that, from the hydrogen permeation and thermal desorption analysis (TDA) results, effective diffusivity and activation energy of hydrogen were changed along the crystallographic orientation distributions. Also, transformation induced plasticity (TRIP) and twinning induced plasticity (TWIP) behavior affecting to the HE resistance preferentially formed in grains with <111> and <110> orientations rather than in those with <001> orientation during plastic deformation. Therefore, the study suggests that reinforcing the <001> microstructure is advantageous for improving HE resistance in 316L ASS.

Solution and solubility of H atoms at the W/Cu interface.

Metallic interfaces are locations where hydrogen (H) is expected to segregate and lead to the formation and stabilization of defects. This work focuses on the tungsten/copper (W/Cu) interface built according to theWbcc(001)/Cuhcp(112-0)orientation. H behavior is subsequently determined at the interface and in its vicinity with electronic structure calculations based on the density functional theory (DFT). The electronic and vibrational properties determined in this way followed a thermodynamic treatment to deliver the solubility of H as a function of the temperature and chemical potential. The 96 interstitial positions we investigated reveal that H predominantly occupies the octahedral (Oh) sites in the copper network. Reversely, H exclusively occupies the tetrahedral (Td) sites in the tungsten network. The solubility of H is higher in the interface plane where both octahedral and tetrahedral sites are occupied. Despite this work is a first step toward kinetic modeling of hydrogen transport across the W/Cu interface, we conclude that theWbcc(001)/Cuhcp(112-0)would behave like a sink where hydrogen isotopes could accumulate.

Numerical simulation of high-pressure jet fire in on-board hydrogen storage cylinders under fire conditions

Hydrogen fuel cell vehicles (HFCVs) may cause fires in the event of an accident. When the high-pressure hydrogen storage cylinders are exposed to fire for a long time, there will be a risk of catastrophic consequences such as leakage, jet fire and explosion. Fire test is the main method to study the safety performance of hydrogen storage cylinders. During the firing process, the wall and internal temperature of the hydrogen storage cylinder rise gradually, and the thermally activated pressure relief device (TPRD) of the cylinder reaches a certain temperature and then releases high-pressure hydrogen to prevent the cylinder from bursting. As the hydrogen storage cylinder is in the fire environment, the release of high-pressure hydrogen will be ignited to form a jet fire and cause damage to personnel and equipment. In this paper, CFD software Fluent was used to numerically simulate the local fire test of the hydrogen storage cylinder with high-temperature air as the fire source. The variation law of cylinder wall temperature, gas temperature and pressure inside the cylinder, and the activation of TPRD were analyzed. At the same time, on the basis of the fire test simulation, a high-pressure hydrogen jet fire simulation numerical model caused by the TPRD action was established. The velocity field, temperature field and hydrogen concentration distribution of the jet fire were obtained, and the overpressure generated by the jet fire and the flame length size were analyzed. The results show that the high-pressure hydrogen released by TPRD was ignited under the fire condition to produce a jet flame and generated an overpressure in the jet direction, and the influence range of the overpressure was smaller than the influence range of the jet flame.

Hydrogen Production from Ammonia Decomposition: A Mini-Review of Metal Oxide-Based Catalysts.

Efficient hydrogen storage and transportation are crucial for the sustainable development of human society. Ammonia, with a hydrogen storage density of up to 17.6 wt%, is considered an ideal energy carrier for large-scale hydrogen storage and has great potential for development and application in the "hydrogen economy". However, achieving ammonia decomposition to hydrogen under mild conditions is challenging, and therefore, the development of suitable catalysts is essential. Metal oxide-based catalysts are commonly used in the industry. This paper presents a comprehensive review of single and composite metal oxide catalysts for ammonia decomposition catalysis. The focus is on analyzing the conformational relationships and interactions between metal oxide carriers and active metal sites. The aim is to develop new and efficient metal oxide-based catalysts for large-scale green ammonia decomposition.

MODELLING OF HYDROGEN FLOW FROM GAS MIXTURES THROUGH NICKEL CAPILLARIES CONSIDERING THE NONUNIFORMITY OF TEMPERATURE DISTRIBUTION

A mathematical model of the flow of hydrogen from gas mixtures through the walls of capillary tubes made of metallic nickel has been developed, taking into account the inhomogeneity of the partial pressure of hydrogen along a long tube, as well as temperature nonuniformity in different regions of the tube. Using the model and relying on experimental data, the kinetic parameters of hydrogen transport were calculated within the temperature range of 600-850 °С and the hydrogen partial pressure range of 0.3-0.8 atm. The model can be used in the design of membrane modules for hydrogen separation from gas mixtures to calculate the length of individual membranes, their number, and the optimal flow rate of the hydrogen-containing gas mixture through the membrane.

Contact electrification characteristics of solid oxygen particle-laden flows in liquid hydrogen transportation

The issue of electrostatic safety in liquid hydrogen systems has garnered increasing attention, especially concerning the potential threat of electrostatic explosions due to the collision-electrification phenomenon of solid oxygen particles formed after air leakage in liquid hydrogen pipelines. To delve into the contact electrification characteristics of solid oxygen particle-laden flows in liquid hydrogen transportation, a mathematical model based on the computational fluid dynamics-discrete element method (CFD-DEM) two-phase flow dynamics has been developed. This model integrates the Hertz contact theory for describing particle collision processes and the condenser model for describing particle collision-electrification. The reliability of this model has been validated in existing literature through its ability to capture the flow characteristics of two-phase flow and the electrification characteristics of particle groups. Using density functional theory to compute the solid oxygen work function and considering the low-temperature properties of liquid hydrogen, a series of numerical studies on the flow sedimentation and electrification characteristics of solid oxygen particle-laden flows in liquid hydrogen pipelines have been conducted. The results indicate that particles carry negative charges after colliding with stainless steel pipe walls, with single charge exchange magnitudes of approximately 10−12C for particle-wall continuous collision processes and 10−14C for particle-particle collision processes, resulting in particle charge-to-mass ratios on the order of tens of μC/kg at the outlet interface. The impact of electrostatic forces on particle motion is significant and cannot be overlooked. Furthermore, the effects of velocity, particle diameter, and pipe diameter on particle charge characteristics have been thoroughly analyzed. At low flow velocities, severe particle settlement occurs, leading to increased collision frequency between particles and walls and significant charge accumulation. Increasing flow velocity can mitigate particle settlement and reduce charge levels. Changes in particle and pipe diameters have a minor impact on particle settlement but can increase single charge amounts with larger particle diameters and intensify particle charging with reduced pipe diameters due to shortened radial travel distances, leading to increased collision frequency. Our study meticulously illustrates the charge characteristics of individual particles and particle groups, providing a theoretical basis for assessing the electrostatic safety of liquid hydrogen transportation systems under extreme conditions.

Development and Field Testing of Multi-Electrode Mixed Potential Electrochemical Sensors for Natural Gas-Hydrogen Mixture Emissions Monitoring

Transportation of hydrogen is one of the greatest hurdles to overcome in the development of a clean hydrogen economy [1]. A cost-effective solution to transportation of hydrogen is to mix it with natural gas (NG) and utilize current pipeline infrastructure for transportation [2]. However, hydrogen embrittlement, the higher diffusivity of H2, and the uncertain state of much of existing infrastructure makes leaks of H2 an environmental and safety concern. Current NG leak detection technologies largely use optical sensors such as IR spectrometers that are incapable of detecting H2 gas [3]. Mixed potential electrochemical sensors (MPES) are low-cost, robust devices capable of detecting a wide variety of gases [4], with the sensitivity and selectivity necessary for point source monitoring of natural gas leaks [5].Multi-electrode MPES devices using Indium Tin Oxide, Au, and La0.87Sr0.13CrO3 and Pt electrodes have previously successfully quantified CH4 in natural gas at the 10-40 ppm level [5]. In this work, we demonstrated that the Au vs. Pt electrode has a low limit of detection of < 3 ppm for H2 in an air atmosphere. We also performed field testing of H2 emissions at CSU’s Methane Emissions Technology Evaluation Center (METEC) in both underground and above-ground emissions of H2 and H2 + natural gas mixes (Figure 1) with successful detection of H2 at the ppm level. Finally, we evaluate the stability of the selectivity and sensitivity during prolonged exposure to H2 and CH4.This work was supported by US Department of Energy Award DE-FE0031864.

Sustainable Production of Hydrogen through High-Temperature Molten Salt Electrolysis

The green and cost-effective production of strategic materials, including steel on a large scale is pivotal for fostering sustainable industrial development. Hydrogen emerges as a key component for clean steel production, but its sustainable and economical generation remains a barrier to widespread utilization in iron and steelmaking, as well as other applications. Conventional water electrolysis, a common method for carbon-free hydrogen production, faces economic challenges, equipment corrosion, and the use of expensive catalysts with high over-potentials, limiting its viability. Additionally, the transportation of hydrogen from the electrolyzer to utilization units poses cost and safety concerns. Addressing these challenges, this presentation discusses the electro-generation of hydrogen in high-temperature molten salts. The generated hydrogen can then be utilized in situ for the production of metals, alloys, and other commercially valuable materials. Leveraging high temperatures improves the thermodynamic potential and efficiency of the water-splitting process. Remarkably, electrolytic hydrogen produced in molten salts, operating at a potential of around 1 V, has the capacity to facilitate the production of a diverse range of materials such as Fe, Mo, W, Ni, and Co-based alloys. References K. Xie, A.R. Kamali*, Energy Convers. Manag. 251 (2022) 114980D. Qiao, K. Xie, A.R. Kamali*, Mater. Adv. 1 (2020) 2225K. Xie, A.R. Kamali*, Int. J. Hydrogen Energy 44 (2019) 2 4353A.R. Kamali*, RSC Advances 10 (2020) 36020A.R. Kamali, US2021009415 (2023)K. Xie, A.R. Kamali*, Green Chem.21 (2019)198

Passivation of Lead-Acid Batteries Lead Negative Electrodes by PbSO4 Crystals: Analysis from Modeling Cyclic Voltammetry Responses

Lead-acid batteries (LABs) play a pivotal role in the energy storage sector with applications spanning from starting-ignition-lightning batteries to grid energy storage. Passivation of lead negative electrodes by PbSO4 crystals is a one fundamental mechanism limiting the performance of LAB. In this regard, we developed an electrochemical mathematical model that simulates the nucleation and growth dynamics of PbSO4 crystals on a flat lead electrode, responsible for its passivation. The model considers the electrochemical dissolution of Pb2+ from lead electrode and the ternary transport of lead, bisulfate, and hydrogen ions in H2SO4 electrolyte. We have validated the model with a rich dataset of cyclic voltammetry (CV) responses collected at several scan rates and several concentrations of H2SO4. The model shows remarkable qualitative and quantitative agreement with the experimental data including the onset potential, center, height, and width of the CV peaks, discharge capacity, and particle size. The model is used to give insights on how different physical and operational parameters can influence the electrochemical response of lead negative electrodes. Keywords: lead-acid battery, nucleation and growth, passivation, cyclic voltammetry