Compressed Gas Storage Research Articles

Hydrogen Storage on Nanoporous Carbon Foam for Electrochemical Applications

To be able to mitigate the threat of climate change, we need an alternative to fossil fuels. The use of hydrogen in fuel cells is an ideal candidate because hydrogen can be produced in many different ways and has a high energy density. However, one challenge in using hydrogen as a fuel is its storage. Storing hydrogen as compressed gas typically requires large pressures to meet US Department of Energy (DOE) targets, which leads to large losses during compression. By using solid state storage, we can use lower pressures for storage. Of the different kinds of solid state storage, physisorption on carbon materials has great potential because of its fast kinetics, reversibility, and the cost effectiveness of carbon materials.In this research, we investigate the storage of hydrogen gas through physical adsorption on a sodium ethoxide-derived carbon foam. This carbon foam has all the necessary requirements of a good hydrogen sorbent: very large surface area and a large micropore volume. This material is also easy to synthesize: sodium ethoxide is pyrolyzed in N2 to make carbon, which is then washed in DI water and vacuum filtered. Unlike many other high surface area carbon materials, this carbon foam does not require a two-step carbonization-activation process, nor does it require a sacrificial template. This means it is more scalable and energy efficient compared to other synthetic carbon materials. [1,2]The hydrogen adsorption capability of this material is tested at both 77K and 298K at elevated pressures (up to 9.5 MPa). Both the excess hydrogen uptake and the total hydrogen uptake are discussed. The values obtained are comparable with benchmark materials such as MOF-5 and IRMOF-20, which have 8 wt% and 10 wt% total uptake at 10 MPa, respectively, [3] and could plausibly meet US DOE targets for light duty vehicle application (5.5 wt% total uptake) at a much lower pressure than conventional compressed gas storage (usually 70 MPa). This work shows the potential of nanoporous carbon materials such as ours to work as a new storage system or as a ‘range extender’ of sorts for existing fuel cell vehicles.[1] Lyth, S. M., Shao, H., Liu, J., Sasaki, K., and Akiba, E., 2014, “Hydrogen Adsorption on Graphene Foam Synthesized by Combustion of Sodium Ethoxide,” Int. J. Hydrogen Energy, 39(1), pp. 376–380.[2] Choucair, M., and Mauron, P., 2015, “Versatile Preparation of Graphene-Based Nanocomposites and Their Hydrogen Adsorption,” Int. J. Hydrogen Energy, 40(18), pp. 6158–6164.[3] Ahmed, A., Seth, S., Purewal, J., Wong-Foy, A. G., Veenstra, M., Matzger, A. J., and Siegel, D. J., 2019, “Exceptional Hydrogen Storage Achieved by Screening Nearly Half a Million Metal-Organic Frameworks,” Nat. Commun., 10(1), pp. 1–9.

Theoretical analysis of design of filament wound type 3 composite cylinder for the storage of compressed hydrogen gas

In the present regime, hydrogen lies in its infancy in the market of automotive fuels. Clean and everlasting substitution of hydrogen for gasoline, to be used as an automotive fuel that would eradicate toxic particulate emission, and would depreciate our dependence on oil reserves for fuel needs is an immediate priority. We can centrally rely on hydrogen fuel if its storage and production become feasible. Therefore, its economic production, safe storage, and trouble-free distribution is an urgency. In this study, a Type 3 composite cylinder for storage of compressed hydrogen gas is designed for storing the fuel at a working pressure of 35 MPa. The theoretical analysis of the designed pressure vessel is simulated using ANSYS software. The model is verified by experimentally testing a similar cylinder for its failure due to burst.

Critical Knowledge Gaps for Understanding Water–Rock–Working Phase Interactions for Compressed Energy Storage in Porous Formations

Storage of air or compressed gas in porous formations is a promising means of large-scale, long-term energy storage, but salt caverns have predominantly been used for storage to date. Porous format...

Hydrogen sorption and desorption behaviors of Mg-Ni-Cu doped carbon nanotubes at high temperature

Hydrogen sorption and storage in a solid matrix can greatly improve its safety and efficiency when compared to the compressed gas or liquid hydrogen storage system, and kinetics mechanisms are of interest towards the development of such materials. In this study, the composites of Mg-Ni-Cu doped with singe-walled carbon nanotubes (Mg-Ni-Cu/CNTs) were synthetized. The activation performance, isothermal hydrogen sorption and desorption were systematically tested, and the experimental data were analyzed using the shrinking core model. The results show that three cycles of hydrogen sorption and desorption may be enough to fully activate Mg-Ni-Cu/CNTs and the stability can be kept for 150 cycles. A 10.1 wt% of Cu and 50.3 wt% of Ni in Mg-Ni-Cu/CNTs facilitates the hydrogen sorption and a reversible hydrogen capacity of ∼3.35 wt% can be achieved at 310 °C and 3.0 atm, and hydrogen capacity and kinetics shows significant decline during contact with 1.0 vol% CO impurity. Considering desorption at 600 °C, the kinetic profiles are about linear and desorption is completed within minutes. The gas-solid reaction processes for hydrogen sorption undergo three different rate-limiting stages, and hydrogen desorption can only be divided into two stages of surface chemical reaction and product layer diffusion.

Novel amorphous aluminum hydroxide catalysts for aluminum–water reactions to produce H2 on demand

Production of aluminum (Al) through electrolysis is an energy intensive process. Al metal with its very high specific energy density of 28.8 MJ kg−1 can serve as an excellent energy storage vector. Al reacts with water (reaction (1)) at room temperature producing clean H2 thus providing an alternative to compressed gas storage.(1)2Al + 6H2O → 2Al(OH)3 + 3H2Reaction (1) does not proceed easily due to the presence of a 2–4 nm passive alumina surface layer. Aluminum hydroxide (Al(OH)3) catalyst disrupts this layer, sustaining reaction (1). The present work focuses on the catalysis aspects of reaction (1) by amorphous Al(OH)3 produced by urea hydrolysis of aluminum nitrate. H2 yields of up to 100% were obtained at 45 °C. Spent reaction product mixtures are autocatalytic with successive additions of Al micropowder (MP) yielding up to 133 ml H2/minute and reaction completion within 10 min at pH ≈ 10. There is an induction time initially due to the presence of dissolved ions, followed by production of H2. Reaction by-products are easily recyclable back to Al metal through subsequent calcining and electrolysis by the Al refining industry, which constitutes the energy storage part of the cycle.

Energetic evaluation of hydrogen storage in metal hydrides

Metal hydrides are considered as promising candidates for hydrogen storage as they exhibit higher energy densities than compressed gas storage storages. This study represents a theoretical thermodynamic analysis of metal hydride-based hydrogen storage systems, focusing mainly on the energy demand to operate the storage system and the resulting efficiency. The main energy demand occurs during hydrogen release. This energy demand is composed of three contributions: the heat required to heat the hydride up to desorption temperature, the heat of reaction and the work of compression to reach the targeted outlet pressure. A sensitivity analysis was performed to demonstrate the impact of several parameters, for example, heat of reaction and hydrogen uptake on the energy balance. The most influential parameter is the heat of reaction. The hydrogen uptake does not have a noticeable influence as long as it is not too low. Several possibilities to improve the efficiency of the storage system are discussed (heat integration and the application of a heat storage system). Heat integration can significantly improve the overall efficiency, whereas the application of a heat storage system does not seem realistic. Compared with other hydrogen storage technologies, metal hydrides can feature higher efficiencies than low-temperature hydrogen storage concepts, for example, liquefied or cryo-adsorbed hydrogen. The efficiencies of a metal hydride storage system are similar to those reached with a system based on liquid organic hydrogen carriers. Copyright © 2016 John Wiley & Sons, Ltd.

Numerical and experimental verification of physical blast thermodynamic model

Helium inventory in big cryogenic systems may be of the order of hundred tons. During the warm up of the machine the helium has to be stored in warm pressurized tanks. A potential rupture of the tank may create a danger to adjacent objects. In order to formulate recommendations concerning storage of compressed gases in close vicinity of nuclear installations, a thermodynamic model of physical blast has been formulated. The model has been experimentally verified in a laboratory scale test rig. To simulate rupture of compressed gas storage tanks, plastic tanks have been used. Scaling of the results to real cases like ITER compressed gas inventory requires good understanding of potential rupture of high volume gas storage tanks. Numerical model of tanks rupture have been elaborated and verified against experimental results. The model allows scaling of thermodynamic simplified description to real gas storage installations.

Adsorbed methane storage for vehicular applications

Abstract The methane storage properties of five benchmark high surface area adsorbent materials were studied at ambient temperature and up to 250 bar service pressure. Using adsorption and sample density data, we evaluated the potential of these materials to store methane in a 110 L pressure vessel. At 50 bar, the adsorbent materials significantly outperformed traditional compressed gas storage. Two materials, an activated carbon and a copper based metal–organic framework (Cu-BTC), also showed improvement over compressed gas storage at 250 bar. Driving ranges calculated from storage data show that with an adsorbent, a 110 L tank filled to 50 bar could have a driving range of up to 140 miles, more than three times the range offered by a plug-in hybrid electric vehicle when operating as a pure battery electric vehicle.

Progress on light metal borohydrides for reversible hydrogen storage

Developing a safe and efficient hydrogen storage system/technology is widely recognized as the bottleneck in promoting the commercial application of hydrogn energy. Compared to compressed gas and liquid hydrogen storage, solid-state hydrogen storage based on materials is considered as the most promising way due to its high energy desity and safety. Among many studied hydrogen storage materials, light metal borohydrides with high hydrogen capacity of over 10 wt%, have attracted intensive attenation as potential onborad hydrogen storage media. The paper reviews the latest progresses made in understanding the hydrogen storage mechansim of light metal borohydrides and improving its reversible dehydrogenation properties by using vaious methods, including cation/anion substitution, constituting reactive hydride composite and nanoconfinement. Our aim is to provide an outline the key scienticfic issue and the future research direction of light metal borohydrides in developing borohydride-based hydrogen storage system.

Numerical study of the nitrogen oxides adsorption and storage

Adsorption of nitrogen oxides in the micropores of solid sorbent becomes an alternative to storage of compressed gas for the next decades. Thus, the effectiveness of the method of nitrogen oxides concentration in the zeolite micropores is experimentally investigated. The model of mass transfer in the adsorber is presented as non-equilibrium. The formulated mathematical problem is a system of three equations: the kinetic equation, the equilibrium equation and the continuity equation. Solution of the mathematical model was achieved using the finite difference method. Comparison and agreement of the numerical results of the developed model with experimental data was performed, the agreement is within 10-12%. When modeling numerical calculations, the complex of temperatures of 298-318 K and pressure of 0.15-3.5 MPa in the adsorber was covered. Based on the obtained data it was concluded that storage of nitrogen oxides in the adsorber, filled with zeolite is an efficient method of concentrating nitrogen oxides (twice more efficiently compared with the conventional gas compression). Mathematical model adequately describes the concentration process, it is amenable to direct solution and can be used in practice to optimize the operation of adsorber and forecast its basic performance features. This technology also allows to reduce the operating pressure that is a very important economic and technological factor in implementing the process at the industrial level.

Numerical analysis of accidental hydrogen releases from high pressure storage at low temperatures

Evaluations of the performance of simplified engineering and CFD models are important to improve risk assessment tools e.g. to predict accurately releases from various types of hydrogen storages. These tools have to predict releases from a wide range of storage pressures (up to 80 MPa) and temperatures (down to 20 K), e.g. cryogenic compressed gas storage covers pressures up to 35 MPa and temperatures between 33 K and 338 K. Accurate calculations of high pressure releases require real gas EOS. This paper compares a number of EOS to predict hydrogen properties typical in different storage types. The vessel dynamics are modeled using a simplified engineering and a CFD model to evaluate the performance of various EOS to predict vessel pressures, temperatures mass flow rates and jet flame lengths. It is shown that the chosen EOS and the chosen specific heat capacity correlation are important to model accurately hydrogen releases at low temperatures.

An experimental investigation of convection heat transfer during filling of a composite-fibre pressure vessel at low Reynolds number

The heat transfer process during filling of an evacuated vessel at low Reynolds number was investigated experimentally using air as the flow medium. The data was analysed using a thermodynamic model similar to one currently in use for the design of systems using commercial carbon fibre reinforced plastic vessels for storage of compressed hydrogen gas. Model assumptions included perfectly-stirred conditions within the vessel, one-dimensional unsteady heat conduction through the composite vessel wall, ideal gas and frictional adiabatic flow conditions through the inlet tube. A transition phenomenon from laminar to turbulent flow was observed by decreasing the inlet diameter while maintaining a similar mass flow rate. Based on the measurements, a new empirical correlation for the Nusselt number under low Reynolds number flow conditions is proposed.

CONCEPTION OF VEHICLE OF INDIVIDUAL PERSONAL TRANSPORT WITH HYBRID PNEUMATIC PROPULSION

This paper describes the conception of an individual personal transport vehicle. The conception of the vehicle is based on a mechanical structure of a bike and on a pneumatic engine as equipment of power support. The research was done as an analysis of existing vehicles with main or supporting gas power systems. In the research the expectations of users, technical resources as well as known constructions were taken into account. At the beginning, the technical properties of known methods and modern vehicles available for individual personal transport of people were reviewed. Next, some vehicles which can meet economic, ecologic and environmental criteria were identified. Finally, the authors proposed usage of extremely small and light-weight vehicles. It appears that the smallest, lightest and most economic construction of vehicles should be modeled on the bike. For power convenience on uphill roads compressed air as a supporting power factor was proposed. It also implied the possibility to use supporting power system as main power engine. However, the economic storage and management of compressed gas required optimization system of gas usage. This optimization depends on pulse wide modulation of air valve flow and possibility of air compression. Air compression is possible by driving downhill or on fixed vehicle by human muscle power. Those circumstances warrant to name such power system a hybrid pneumatic propulsion.

Large-scale hydrogen energy storage in salt caverns

Large-scale energy storage methods can be used to meet energy demand fluctuations and to integrate electricity generation from intermittent renewable wind and solar energy farms into power grids. Pumped hydropower energy storage method is significantly used for grid electricity storage requirements. Alternatives are underground storage of compressed air and hydrogen gas in suitable geological formations. Underground storage of natural gas is widely used to meet both base and peak load demands of gas grids. Salt caverns for natural gas storage can also be suitable for underground compressed hydrogen gas energy storage. In this paper, large quantities underground gas storage methods and design aspects of salt caverns are investigated. A pre-evaluation is made for a salt cavern gas storage field in Turkey. It is concluded that a system of solar-hydrogen and natural gas can be utilised to meet future large-scale energy storage requirements.

Monitoring phase behavior of hydrogen confined in carbon nanopores byin-situSmall Angle Neutron Scattering technique

ABSTRACTWe report on the use ofin-situsmall angle neutron scattering (SANS) technique to study the phase behavior of hydrogen confined in narrow pores of ultramicroporous carbon (UMC) with a very large surface area (2630 m2/g) and pore volume (1.3 cm3/g). The effect of pore size and pressure on hydrogen adsorbed on UMC at room temperature and pressures up to ∼200 bar were investigated. In a previous experiment, we have measured the density of adsorbed H2gas in the nanopores and mesopores of polyfurfuryl alcohol-derived activated carbon (PFAC) by SANS technique. Here, a comparative SANS study between the UMC and PFAC was conducted in order to further investigate the densification of H2as a function of pore size and pressure. Initial results suggest that the density of confined H2in both UMC and PFAC is considerably higher than that of the bulk hydrogen gas. The density is systematically higher in the narrow pores and decreases with increasing pore size. These results clearly demonstrate the advantage of adsorptive storage over compressed gas storage and emphasize the greater efficiency of micropores over mesopores in the adsorption process, which can be used to guide the development of new carbon adsorbents tailored for maximum H2storage capacities at near-ambient temperatures.

Development and Validation of a Numerical Thermal Simulation Model for Compressed Hydrogen Gas Storage Tanks

Development and Validation of a Numerical Thermal Simulation Model for Compressed Hydrogen Gas Storage Tanks

Density Measurements in a Supersonic Microjet Using Miniature Rainbow Schlieren Deflectometry

Understanding of the structure of complex supersonic flows requires high-resolution, nonintrusive measurements across the whole field. The measurement requirements are even more challenging when dealing with small-scale systems. In this study, we apply the miniature rainbow schlieren deflectometry system to measure the density field in underexpanded microjets from an orifice injector of 500 μm diameter. The injector is used to replicate the practical scenario of accidental leakage from a compressed gas storage facility. Experiments were conducted for a range of supply pressures P s , although the majority of the results are presented for P s = 860 kPa. Experimental schlieren images were analyzed to determine the density contours in an axisymmetric domain with a field of view of 1.5 mm radius and 7.5 mm length, at a spatial resolution of 25 μm. Pressure, temperature, and Mach number profiles (normalized by the values at the orifice) were also obtained along the jet centerline. Results show features similar to those observed in underexpanded macrojet from a sonic nozzle; multiple shock-cell structures with expansion and compression fans, freejet boundary, incident, normal, and reflected shock waves, subsonic slip strip, and outer shear layer. The miniature rainbow schlieren deflectometry technique is shown to provide high-quality quantitative data to explain the structural details of underexpanded microjets.

2132 砕氷層を用いたメタン・炭酸ガス混合ハイドレートの生成特性(G06-5 熱工学(5) 伝熱(3),21世紀地球環境革命の機械工学:人・マイクロナノ・エネルギー・環境)

There is a significant difference in the amount of biogas which is produced from sewage treatment process between summer and winter. Therefore, an efficient storage method is necessary for the effective utilization of biogas. The hydrate storage system using the snow is expected as an energy saving method. In the study, gas hydration was investigated as the influence of bulk density of ice layer in the formation and ambient temperature in the storage. As the results of the experiment, it was found that the optimum bulk density for the formation was 0.69g/cm^3 and the ambient temperature of 0℃ was suitable for the storage. And, it was also found that the required energy of the hydrate storage could be reduced from that of the compressed gas storage when the snow was used as a host material of hydrate formation.

What a Gas! Delivery, Storage, and Use of Compressed Gas Cylinders

This article discusses common safe‐handling practices for compressed gas cylinder delivery, storage, and use.

Simulation and operational assessment for a small autonomous wind–hydrogen energy system

A case study with respect to the current trends in hydrogen technology and market developments is presented in this paper. The main goal is to design an autonomous, environmentally sustainable and zero emission power system using commercially available equipment. In order to achieve the optimum cost effective solution, its limitations are defined by simulating its performance over a year. A scenario is chosen which is representative of an area with significant wind potential, where the grid connection is relatively long or the construction of the line itself would irretrievably harm the environment. This study simulated the operation of a small, remote hotel primarily powered by a wind turbine and supported by a hydrogen energy system incorporating a medium pressure electrolyzer, a compressed hydrogen gas storage unit and a PEM fuel cell stack. The simulated load is biased towards a particular season as in the case of a small hotel for summer holidays. This arrangement takes advantage of the long period of low load during the “off peak” season, which enables the production of reserves of hydrogen to supplement the wind generated electricity during the “peak” season, avoiding the use of a large electrolyzer system, which is the most expensive and vulnerable component. The simulation results showed that for this particular system, a wind turbine rated at four times the peak load power associated with the optimum combination of an electrolyzer and a hydrogen storage unit would meet the electrical energy needs of a 10 bedroom, non-luxury hotel under the supervision of a load management controller.