Hydrogen Storage Container Research Articles

Effects of hydrogen cycling on the performance of 70 MPa high-pressure hydrogen storage tank liners formed by different processes

Current research on the compatibility between plastic liners utilized in Type IV high-pressure hydrogen storage containers and hydrogen remains insufficiently comprehensive. Therefore, further exploration into how the high-pressure hydrogen storage process influences the crystalline phase transition of polymers is essential to improve the applicability and safety of plastic lining materials. This study primarily investigated the preparation of polyamide 1012 (PA1012) and polyamide 11 (PA11) through rotational molding and injection molding, denoted as Roto-PA1012/Roto-PA11 and In-PA1012/In-PA11, respectively. Considering the operational parameters of the 70 MPa Type IV hydrogen storage tank, we conducted hydrogen cycling experiment using the long carbon chain polyamide (LCPA) liner materials and comprehensively analyzed the morphology, crystal structure, grain size, mechanical properties and hydrogen barrier properties of polyamide materials before and after hydrogen cycling. The results showed that after hydrogen cycling, no significant changes were observed in Roto-PA1012/Roto-PA11, while In-PA1012/In-PA11 demonstrated severe foaming. Rotational molding of LCPA maintained stable mechanical and hydrogen barrier properties throughout the hydrogen cycle, which can be attributed to the favorable thermodynamic stability of the α' form achieved during rotational molding, leading to uniform and stable crystal sizes. In conclusion, this study provides a theoretical foundation for future investigations into the molding process and material selection of high-barrier polymer liners, as well as the actual production and utilization of Type IV hydrogen storage tanks.

Effect of welding current on the mechanical properties of Al 5083 alloy processed using high-current gas metal arc welding

This study investigated the effect of welding current during gas metal arc welding (GMAW) on the microstructure and composition of an Al 5083 alloy. As the welding current increased from 650 to 950 A, several changes were observed in the heat-affected zone (HAZ): grain coarsening and the formation of liquation cracks, and in the weld zone (WZ): increasing average secondary arm spacing and Mg loss. Therefore, the welding currents above 800 A are likely to cause liquation cracks in the HAZ and deterioration of the alloy's mechanical properties. Thus, welding condition with low heat input must be applied to improve the mechanical properties of the welds. This study provides a correlation between the weldability of Al 5083 alloy and welding current, offering a competitive advantage of liquid hydrogen storage containers.

Small-Scale High-Pressure Hydrogen Storage Vessels: A Review.

Nowadays, high-pressure hydrogen storage is the most commercially used technology owing to its high hydrogen purity, rapid charging/discharging of hydrogen, and low-cost manufacturing. Despite numerous reviews on hydrogen storage technologies, there is a relative scarcity of comprehensive examinations specifically focused on high-pressure gaseous hydrogen storage and its associated materials. This article systematically presents the manufacturing processes and materials used for a variety of high-pressure hydrogen storage containers, including metal cylinders, carbon fiber composite cylinders, and emerging glass material-based hydrogen storage containers. Furthermore, it introduces the relevant principles and theoretical studies, showcasing their advantages and disadvantages compared to conventional high-pressure hydrogen storage containers. Finally, this article provides an outlook on the future development of high-pressure hydrogen storage containers.

Stability and Failure Mechanisms of Al2O3|Al Bilayer Coatings Exposed to 300 Bar Hydrogen at 673 K

Hydrogen barrier coatings are important for future hydrogen economy to enable materials for applications in hydrogen tanks. In the present study, coatings consisting of amorphous Al2O3 (≈100 nm) synthesized by plasma ion‐assisted deposition on top of crystalline metallic Al (≈100 nm) are exposed to 300 bar hydrogen pressure at 673 K for 6 days. This is done to mimic and accelerate conditions in hydrogen storage containers for metallic hydrides. They remain intact after such harsh conditions, although changes do occur. Blister‐like features are observed consisting of a buckled oxide layer while the metallic Al layer underneath is retracted. As these features are also found for coatings annealed under 1 bar Ar atmosphere it is concluded that they are not related to the formation of gas bubbles but they form due to solid‐state dewetting. This is different to literature observation where H2 bubbles are reported as a consequence of interface diffusion of H/H+ species present due to the initial precursor used for film deposition. The mechanical properties of the coatings, which are evaluated from nanoindentation load–displacement curves, change only moderately. Overall, the study shows that Al2O3|Al coatings are suitable candidates to prevent hydrogen ingress, but dewetting due to long‐term exposure at elevated temperatures must be prevented.

Integration of the PEMFC with a hydrogen production device adopting sodium borohydride and metal cobalt catalyst

Hydrolysis technology that releases hydrogen from chemical hydrogen storage materials is a method to produce hydrogen. Hydrogen storage has excellent development potential and is also one of the sources of large amounts of hydrogen. A sodium borohydride hydrogen production experiment was carried out based on steam hydrolysis technology. The system reaction tank is divided into a water-carrying bed and a catalyst bed. A mixed aqueous solution with a concentration of 1 wt% sodium hydroxide (NaOH) + 10 wt% sodium borohydride (NaBH4) was used for the hydrogen production reaction test. These experiments determined the appropriate aqueous solution and water vapor combination, and optimal parameters for hydrogen production. The hydrogen production catalyst powder, blend ratio, different steel ball ratios, and ball milling time at the steam hydrogen production end will all affect the powder's fineness and hydrogen production stability. Under catalyst temperature control, the by-products solidify at a specific temperature, which affects the gas passage and causes blockage. Increasing the hydrogen production in an aqueous solution requires a Co2+/Al2O3 catalyst, or a temperature control method to catalyze hydrogen production to obtain stable hydrogen production suitable for emergencies without hydrogen storage containers. This experiment built a hydrogen production system combined with a fuel cell for power generation testing. The test process and results indicate whether the aqueous solution and steam technology can be an effective solution when the hydrolysis hydrogen production technology is matched.

Performance analysis of solar-assisted-geothermal combined cooling, heating, and power (CCHP) systems incorporated with a hydrogen generation subsystem

In this study, the response surface method (RSM) and transient assessment was used to evaluate the energy and economic performance of a solar-assisted-geothermal combined cooling, heating, and power system (SG-CCHP). The proposed SG-CCHP process consisted of two steam turbines (STs), photovoltaic/thermal (PV/T) collectors, a fuel cell circuit, an absorption chiller, and a heat pump (HP), with battery cells and a hydrogen storage container as the power storage modules. The system's performance was investigated using the TRNSYS modeling tool. The design of experiments (DOE) approach was used to determine the optimal arrangement of the SG-CCHP scheme by controlling the key design factors. A number of simulation scenarios were generated using DOE, and their outcomes were analyzed using RSM. The transient interactions of the controlling design factors on the techno-economic metrics were given after RSM identified the optimal SG-CCHP scheme. The number of PV/T panels, steam turbine capacity, fuel cell power, HP heating capacity and absorption chiller cooling capacity were considered as decision variables. Total electricity consumption (TEU) and auxiliary boiler fuel consumption (ABFU) as indicators of primary energy consumption of the system and predicted average vote (PMV) as an index of thermal comfort of the system and life cycle cost (LCC) as an economic measure to 4 objective functions were selected for optimization. The results indicated that the optimal system significantly reduced its annual life cycle costs, thermal comfort score, total power usage, and auxiliary boiler natural gas usage. The findings also demonstrated that the SG-CCHP system's integration of battery and hydrogen storage components achieved the maximum efficiencies of 90%, 60%, 23%, and 18% for the electrolyzer, fuel cell, PV/T solar collector, and electrical generator, respectively over a year. The optimization results showed that the system cycle cost (LCC) is $514,188.21 per year, the system comfort coefficient (PMV) is 0.257 per year, the boiler fuel consumption is 46,271.40 cubic meters per year, and the total electricity consumption is −50,082.37 kWh per year.

Stress Reduction of a V-Based BCC Metal Hydride Bed Using Silicone Oil as a Glidant

The large volume expansion and self-locking phenomenon of metal hydride particles during hydrogen sorption often leads to a high stress concentration on the walls of a container, which may cause the collapse of the container. In present study, silicone oil was investigated as a glidant for a V-based BCC metal hydride bed to alleviate the stress concentration during hydrogen sorption. The results indicated that the addition of 5 wt% silicone oil slightly reduced the initial hydrogen storage capacity of V40Ti26Cr26Fe8 (particle size: ~325 μm) but improved the absorption reversibility, regardless of the oil viscosity. It was observed that silicone oil formed a thin oil layer of 320~460 nm in thickness on the surface of the V40Ti26Cr26Fe8 particles, which might improve the fluidity of the powder, reduce the self-locking phenomenon and alleviate the stress concentration on the container walls. Consequently, the maximum strain on the surface of the hydrogen storage container decreased by ≥22.5% after adding 5 wt% silicone oil with a viscosity of 1000 cSt.

Recent Advances and Prospects in Design of Hydrogen Permeation Barrier Materials for Energy Applications-A Review.

The hydrogen infrastructure involves hydrogen production, storage and delivery for utilization with clean energy applications. Hydrogen ingress into structural materials can be detrimental due to corrosion and embrittlement. To enable safe operation in applications that need protection from hydrogen isotopes, this review article summarizes most recent advances in materials design and performance characterization of barrier coatings to prevent hydrogen isotopes’ absorption ingress and permeation. Barriers are crucial to prevent hydride formation and unwanted hydrogen effects to increase safety, materials’ lifetime and reduce cost for applications within nuclear and renewable energy. The coating may be applied on a material that requires protection from hydrogen pick-up, transport and hydride formation in hydrogen storage containers, in pipelines, spent nuclear fuel storage or in nuclear reactors. While existing, commercial coatings that have been much in use may be satisfactory for various applications, it is desirable to evaluate whether alternative coating concepts can provide a greater resistance to hydrogen isotope permeation along with other improved properties, such as mechanical strength and thermal resistance. The information presented here is focusing on recent findings within the past 5–7 years of promising hydrogen barriers including oxides, nitrides, carbon, carbide, MAX-phases and metals and their mechanical strength, hydrogen pick-up, radiation resistance and coating manufacturing techniques. A brief introduction to hydrogen permeation is provided. Knowledge gaps were identified to provide guidance for material’s research prospects.

A study on a representative heat source model for simulating laser welding for liquid hydrogen storage containers

Laser welding enhances the productivity with high speed, and minimizes thermoelastic distortion with a concentrated heat source for a narrow area over a short period of time. With these strengths various industries such as the automobile, aviation, and shipbuilding adopt that. However welding distortion is still one of principal problems, simulation of distortion and corresponding design are very important for applying that technology. Naturally accurate laser welding heat source model is needed, but there is not representative heat source model which can cover diverse types of models. This study proposes a multi-layered heat source model as a representative model, and develops a welding heat source that complies with welding conditions by comparing it to the bead-on-plate welding experiment on 304L stainless steel, a material used for cryogenic purposes with liquid hydrogen condition. To derive a welding heat source, a parametric study was used as it was able to identify an appropriate solution by changing the parameter values constituting the heat source for finite element analysis, where the physical properties for each temperature were applied. For this process optimization method was applied, and the objective function and constraints were defined based on the value of temperature through simulation, also a global optimization algorithm was adopted. In this study, we suggest a representative model that can be used under most welding conditions; this is a method that can be of great help in future welding distortion analyses and can be used in a design that can tolerate distortion.

Experimental Study on the Thermal Effect according to the Distance around a Hydrogen Jet Flame

In this study, the safe distance in the case of a hydrogen vehicle fire was analyzed according to the temperature distribution around a hydrogen gas jet flame formed by the thermally activated pressure relief device operation of a hydrogen storage container. The experiment was conducted while 70 MPa hydrogen gas was released from a 1.8-mm-diameter nozzle to a 1.8- × 1.8 m fire-resistant structure wall for distances of 2 and 4 m between the nozzle output and the wall. To analyze the temperature around the hydrogen gas jet flame, five fire-fighting heat-protective hood test samples, certified by the Korea Fire Institute, and temperature sensors were installed every 1 m from the center of the jet flame in the vertical direction to the direction of the flame. In the experiment, the temperature around the jet flame was measured to observe the safe distance for firefighters. The results show that the safe distances at 70°C or less, which is harmless to firefighters, were 5 m without a heat-protective hood and 3 m with a heat-protective hood. In addition, it was confirmed that the direction of the jet flame and blocking by obstacles affect the safe distance during fire-fighting and rescue activities by firefighters.

Experimental investigation on subcooling of liquid hydrogen by helium gas injection through evacuation

AbstractSubcooling is the process of bringing down the temperature of liquids lower than that of the boiling point of the corresponding vapor pressure. The performance of subcooling of cryogenic liquids mainly depends on the heat‐inleak of the system, the helium injection mass flow rate, helium injection temperature, and helium injection nozzle pattern. This paper presents an alternative method, by making use of the least heat in the leakage of the liquid hydrogen storage container, which is quite possible because containers with excellent thermal insulation are commercially available nowadays. The process involved is rapid evacuation through gas ejectors, thus reducing the effect of temperature. The advantage and the process of evacuation leading to subcooling in a unique manner are the objective of this article. The experimental results are discussed in comparison with the thermophysical process involved in the subcooling operation. A comparative study is also carried out with the theoretical heat exchange process in which helium is used as a medium for the economy of the stated process. It is stated that the current process of subcooling through evacuation is superior to the conventional heat exchange process.

Research Progress of Cryogenic Materials for Storage and Transportation of Liquid Hydrogen

Liquid hydrogen is the main fuel of large-scale low-temperature heavy-duty rockets, and has become the key direction of energy development in China in recent years. As an important application carrier in the large-scale storage and transportation of liquid hydrogen, liquid hydrogen cryogenic storage and transportation containers are the key equipment related to the national defense security of China’s aerospace and energy fields. Due to the low temperature of liquid hydrogen (20 K), special requirements have been put forward for the selection of materials for storage and transportation containers including the adaptability of materials in a liquid hydrogen environment, hydrogen embrittlement characteristics, mechanical properties, and thermophysical properties of liquid hydrogen temperature, which can all affect the safe and reliable design of storage and transportation containers. Therefore, it is of great practical significance to systematically master the types and properties of cryogenic materials for the development of liquid hydrogen storage and transportation containers. With the wide application of liquid hydrogen in different occasions, the requirements for storage and transportation container materials are not the same. In this paper, the types and applications of cryogenic materials commonly used in liquid hydrogen storage and transportation containers are reviewed. The effects of low-temperature on the mechanical properties of different materials are introduced. The research progress of cryogenic materials and low-temperature performance data of materials is introduced. The shortcomings in the research and application of cryogenic materials for liquid hydrogen storage and transportation containers are summarized to provide guidance for the future development of container materials. Among them, stainless steel is the most widely used cryogenic material for liquid hydrogen storage and transportation vessel, but different grades of stainless steel also have different applications, which usually need to be comprehensively considered in combination with its low temperature performance, corrosion resistance, welding performance, and other aspects. However, with the increasing demand for space liquid hydrogen storage and transportation, the research on high specific strength cryogenic materials such as aluminum alloy, titanium alloy, or composite materials is also developing. Aluminum alloy liquid hydrogen storage and transportation containers are widely used in the space field, while composite materials have significant advantages in being lightweight. Hydrogen permeation is the key bottleneck of composite storage and transportation containers. At present, there are still many technical problems that have not been solved.

Ultra-high gas barrier composites with aligned graphene flakes and polyethylene molecules for high-pressure gas storage tanks

Despite polymers have great advantage in improving the energy density of hydrogen storage containers due to their lightweight characteristic, the production of high gas barrier polymers in a low-cost and high-efficiency manner remains a challenge. Here, polyethylene/graphene flakes (PE/GFs) composite films with ultra-high gas barrier properties were produced by no-boundary constraints hot-pressing method. Theoretical analysis showed that an extensional-shear coupled flow was generated inside the polymer melts and the shear-flow force near the polymer melts surface is always higher than that inside the melts during this process, which is responsible for the alignment of GFs and PE molecules. The DSC results indicated that the crystallinity of the composites after hot-pressing is increased by about 10%. The quantitative results of positron annihilation lifetime spectrum (PALS) showed that the fractional free volume of composites is reduced from 6.52 vol% to 5.43 vol%. As a consequence of the synergistic effect of the above aspects, the barrier performance of the composites has been significantly improved, and the helium leak rate of the composites reached an astonishing 3.92 × 10−9 Pa•m3/s with only 0.5 wt% GFs, outperforming unoriented pure PE with a decrease of 98.6%. Moreover, the tensile strength and Young's modulus of the oriented composites were increased by 31.4% and 21.1%, respectively. The work presented here demonstrates that the simple, fast, and economical preparation method can be readily used to produce composites with superior barrier performance, which will provide great reference for the processing technology of hydrogen storage containers.

Numerical Analysis of Hydrogen Leakage from Hydrogen Storage Container under Various Circumstances

A numerical simulation method by using the realizable k-ε model of computational fluid dynamics (CFD) proposed by establishing the model of hydrogen leakage of a high-pressure hydrogen storage container is presented in this paper. By setting different environmental wind speeds, leakage apertures, and leakage locations, multiple simulation calculations are performed to compare test results. As the wind speed increases, the degree of turbulence of hydrogen increases. Large aperture and bottom side leakage cause more serious hazardous area of personnel than small aperture and top leakage do. Base on the results, it can provide reference for dealing with the leakage of high-pressure hydrogen storage containers.

Measurement of Thermal Expansion over a Wide Range of Temperatures by a Pushrod Dilatometer

The coefficient of thermal expansion (CTE) is an intrinsic property of a material and is a very important value in various science and engineering fields. Among various methods for measuring the CTE, the dilatometer is the most commonly used equipment, but it has not been frequently used for measurement due to its performance at very low temperature. In this study, we used a pushrod dilatometer to measure the CTE of candidate metallic alloys for liquefied hydrogen storage containers in the temperature range from −170 °C to 70 °C. In order to secure the reliability of the measured cryogenic CTE values of the metallic alloys, we introduced a method for calibrating the pushrod dilatometer system by using a standard specimen, and we assessed the uncertainty of measurement associated with the process according to the ISO Guide to the Expression of Uncertainty in Measurement. As a result, reliable CTEs for the metallic alloys for liquefied hydrogen storage containers with an uncertainty of measurement of 2.2% ∼ 4.7% according to the measurement temperature were obtained; the results showed good agreement, within the level of the uncertainty of measurement, with other data found in the literature.

Solid-Phase Hydrogen Storage Based on NH3BH3-SiO2 Nanocomposite for Thermolysis

Current H2-proton exchange membrane fuel cell systems available for commercial applications employ heavy and high-risk physical hydrogen storage containers. However, these compressed or liquefied H2-containing cylinders are only suitable for ground-based electric vehicles, because although highly purified H2 can be stored in a cylinder, it is not compatible with unmanned aerial vehicles (UAVs), which require a lighter and more stable energy source. Here, we introduce a chemical hydrogen storage composite, composed of ammonia borane (AB) as a hydrogen source and various heterogeneous catalysts, to elevate the thermal dehydrogenation rate. Nanoscale SiO2 catalysts with a cotton structure dramatically increase the hydrogen evolution rate on demand, while simultaneously lowering the startup temperature for AB thermolysis. Results show that the dehydrogenation reaction of AB with a cotton-structured SiO2 nanocatalyst composite occurs below 90°C, the reaction time is less than a minute, and the hydrogen generation yield is over 12 wt%, with an activation energy of 63.9 kJ·mol-1.

Clathrate hydrates for energy storage and transportation

Formation pressure of mixed hydrogen + methane, hydrogen + ethane and hydrogen + propane hydrates can be controlled by the gas phase composition allowing these hydrates to be considered as promising hydrogen storage containers. At low methane (ethane) concentration in the gas phase, the hydrate of the cubic structure II is formed, and at the methane concentration exceeding 6 mol.% (1 mol.% for ethane) the cubic structure I is formed. The mass percentage of hydrogen in the hydrate phase depends on the second gas concentration in the gas phase as well as on the thermodynamic conditions of hydrate formation. At a low concentration of methane (ethane) in the gas phase, the mass percentage of hydrogen in the hydrate can reach 2.5 wt% at 250 K. The curves of the monovariant equilibrium “gas-hydrate-ice Ih” for double hydrates are calculated and found to be in agreement with the available experimental data. Thermodynamic properties of mentioned mixed hydrates allow to considering mixed hydrates as appropriate materials for hydrogen storage.

Novel determination method of charge transfer coefficient of PEM fuel cell using the Lagrange’s multiplier method

This paper presents an evaluation of the transfer coefficient of a reversible PEM fuel cell by using the Lagrange’s undetermined multiplier technique. In a first step, the technique using the activation polarization was presented. Then we put the stress on the Lagrange’s undetermined multiplier technique. The mathematical bases of this method are presented. Subsequently, an experimental determination of the transfer coefficient was carried out by using the two methods. For that purpose, a kit called Hydrocar, combining a solar panel, a reversible PEM fuel cell (which is a combination of fuel cell and electrolyser), hydrogen and oxygen storage containers, and a 3 Volts alkaline battery, was experimented. The experimental study of the solar panel was made. Some parameters of the solar panel were determined, such as the fill factor FF, the efficiency η, the short circuit current ISC, the open circuit voltage VOC, the maximum power Pm, and the series resistance Rs.The internal resistance Ri and the optimal resistance Ropt of the fuel cell were determined. Finally, experimental study of the electrolyser and the PEM fuel cell was performed. By using the activation polarization, an evaluation of the transfer coefficient was made. Then an evaluation of the transfer coefficient was made by using the Lagrange’s undetermined multiplier technique which takes into account the ohmic polarization, the activation polarization and also the current-power characteristic of the fuel cell.

Hydrogen storage and electrochemical properties of mechanically alloyed La1.5-xGdxMg0.5Ni7 (0 ≤ x ≤ 1.5)

RE-Mg-Ni-based alloys with their unique superlattice structures have been considered to be possible candidates for hydrogen storage containers as well as electrodes in Ni-MHx batteries. In this study, mechanical alloying with subsequent annealing in the argon atmosphere at 1123 K for 0.5 h, was applied to produce the La1.5-xGdxMg0.5Ni7 (0 ≤ x ≤ 1.5) alloys. Hydrogen storage and electrochemical properties of the synthesized material have been investigated. For example, at the 50th cycle the La1.5Mg0.5Ni7 material shows a much lower reversible electrochemical capacity than La1.25Gd0.25Mg0.5Ni7 alloy. Additionally, the partial substitution of La by Gd improves the kinetics of hydrogen absorption. On the other hand, the stability of the electrochemical discharge capacity increases with the increasing value Gd up to x = 1.0. However, a significant reduction in the discharge capacity was observed for the Gd content above x = 0.25. From the application point of view, only La1.25Gd0.25Mg0.5Ni7 alloy show great potential in the future application as electrode material in Ni-MHx batteries.

Hot spinning formability of aluminum alloy tube

Spinning is a processing method in which a metal material such as a plate or pipe is pressed against a roller tool while rotating material with a forming die. Hot spinning processing is used for the production of high pressure hydrogen storage container. As an aluminum liner material for a high pressure hydrogen storage container, an Al-Mg-Si alloy is used from the viewpoint of hydrogen embrittlement resistance and strength. However, wrinkles and cracks generated during the formation of the liner material by hot spinning may cause breakage of the container. In this study, hot spinning is performed on Al-Mg-Si (A6063) alloy by changing processing conditions and processing temperature. After that, the effect of processing conditions and processing temperature on surface texture and wall thickness change was investigated. The results are followings, if the number of passes is large, the unevenness of the inner surface is small, but the length of the processed portion increases and the wall thickness decreases. On the other hand, when the temperature is high, the unevenness on the inner surface become large, the length of the worked portion hardly increases, and the wall thickness increases.