Metal hydride hydrogen storage tank for fuel cell utility vehicles

The “low-temperature” intermetallic hydrides with hydrogen storage capacities below 2 wt% can provide compact H₂ storage simultaneously serving as a ballast. Thus, their low weight capacity, which is usually considered as a major disadvantage to their use in vehicular H₂ storage applications, is an advantage for the heavy duty utility vehicles. Here, we present new engineering solutions of a MH hydrogen storage tank for fuel cell utility vehicles which combines compactness, adjustable high weight, as well as good dynamics of hydrogen charge/discharge. The tank is an assembly of several MH cassettes each comprising several MH containers made of stainless steel tube with embedded (pressed-in) perforated copper fins and filled with a powder of a composite MH material which contains AB₂- and AB₅-type hydride forming alloys and expanded natural graphite. The assembly of the MH containers staggered together with heating/cooling tubes in the cassette is encased in molten lead followed by the solidification of the latter. The tank can provide >2 h long H₂ supply to the fuel cell stack operated at 11 kWe (H₂ flow rate of 120 NL/min). The refuelling time of the MH tank (T = 15–20 °C, P(H₂) = 100–150 bar) is about 15–20 min.     

Advancements and current technologies on hydrogen fuel cell applications for marine vehicles

Maritime industry has led renewable energy sources for the greener environment and efficient vehicles that effect by increasing population and energy demands. Hydrogen is one of the most popular of these renewable energy sources and one of the most favourable research area, worldwide. In this study, authors reported the usage of hydrogen fuel cells in marine transport as main power forwarder, their advantages and challenges under the lights on state of art and furthermore new technologies perspective. The latest research activities, hydrogen production and storage methods with challenges are analyzed and the developments of fuel cell based marine vehicles are discussed. In detailed, newly approachment of electrolyses from seawater for sustainable fuel necessity is discussed. As a result, this forseen study is important in terms of handling energy from seawater and compiling the latest technology for marine transport.     

Recent challenges of hydrogen storage technologies for fuel cell vehicles

Fuel cell vehicles have a high potential to reduce both energy consumption and carbon dioxide emissions. However, due to the low density, hydrogen gas limits the amount of hydrogen stored on board. This restriction also prevents wide penetration of fuel cells. Hydrogen storage is the key technology towards the hydrogen society. Currently high-pressure tanks and liquid hydrogen tanks are used for road tests, but both technologies do not meet all the requirements of future fuel cell vehicles. This paper briefly explains the current status of conventional technologies (simple containment) such as high-pressure tank systems and cryogenic storage. Another method, hydrogen-absorbing alloy has been long investigated but it has several difficulties for the vehicle applications such as low temperature discharge characteristics and quick charge capability due to its reaction heat. We tested a new idea of combining metal hydride and high pressure. It will solve some difficulties and improve performance such as gravimetric density. This paper describes the latest material and system development.     

Efficiencies of hydrogen storage systems onboard fuel cell vehicles

Energy efficiency, vehicle weight, driving range, and fuel economy are compared among fuel cell vehicles (FCV) with different types of fuel storage and battery-powered electric vehicles. Three options for onboard fuel storage are examined and compared in order to evaluate the most energy efficient option of storing fuel in fuel cell vehicles: compressed hydrogen gas storage, metal hydride storage, and onboard reformer of methanol. Solar energy is considered the primary source for fair comparison of efficiencies for true zero emission vehicles. Component efficiencies are from the literature. The battery powered electric vehicle has the highest efficiency of conversion from solar energy for a driving range of 300 miles. Among the fuel cell vehicles, the most efficient is the vehicle with onboard compressed hydrogen storage. The compressed gas FCV is also the leader in four other categories: vehicle weight for a given range, driving range for a given weight, efficiency starting with fossil fuels, and miles per gallon equivalent (about equal to a hybrid electric) on urban and highway driving cycles.     

Comments on solid state hydrogen storage systems design for fuel cell vehicles

In recent years, significant research and development efforts were spent on hydrogen storage technologies with the goal of realizing a breakthrough for fuel cell vehicle applications. This article scrutinizes design targets and material screening criteria for solid state hydrogen storage. Adopting an automotive engineering point of view, four important, but often neglected, issues are discussed: 1) volumetric storage capacity, 2) heat transfer for desorption, 3) recharging at low temperatures and 4) cold start of the vehicle. The article shall help to understand the requirements and support the research community when screening new materials.     

Off-grid solar powered charging station for electric and hydrogen vehicles including fuel cell and hydrogen storage

This paper designs an off-grid charging station for electric and hydrogen vehicles. Both the electric and hydrogen vehicles are charged at the same time. They appear as two electrical and hydrogen load demand on the charging station and the charging station is powered by solar panels. The output power of solar system is separated into two parts. On part of solar power is used to supply the electrical load demand (to charge the electric vehicles) and rest runs water electrolyzer and it will be converted to the hydrogen. The hydrogen is stored and it supplies the hydrogen load demand (to charge the hydrogen-burning vehicles). The uncertainty of parameters (solar energy, consumed power by electrical vehicles, and consumed power by hydrogen vehicles) is included and modeled. The fuel cell is added to the charging station to deal with such uncertainty. The fuel cell runs on hydrogen and produces electrical energy to supply electrical loading under uncertainties. The diesel generator is also added to the charging station as a supplementary generation. The problem is modeled as stochastic optimization programming and minimizes the investment and operational costs of solar and diesel systems. The introduced planning finds optimal rated powers of solar system and diesel generator, operation pattern for diesel generator and fuel cell, and the stored hydrogen. The results confirm that the cost of changing station is covered by investment cost of solar system (95%), operational cost of diesel generator (4.5%), and investment cost of diesel generator (0.5%). The fuel cell and diesel generator supply the load demand when the solar energy is zero. About 97% of solar energy will be converted to hydrogen and stored. The optimal operation of diesel generator reduces the cost approximately 15%.     

Design tool for estimating metal hydride storage system characteristics for light-duty hydrogen fuel cell vehicles

The U.S. Department of Energy (DOE) has developed the Framework model to simulate fuel cell-based light-duty vehicle operation for various hydrogen storage systems. This transient model simulates the performance of the storage system, fuel cell, and vehicle for comparison to DOE's Technical Targets using four drive cycles. Metal hydride hydrogen storage models have been developed for the Framework model. Despite the utility of this model, it requires that material researchers input system design specifications that cannot be easily estimated. To address this challenge, a design tool has been developed that allows researchers to directly enter physical and thermodynamic metal hydride properties into a simple sizing module that then estimates the systems parameters required to run the storage system model. This design tool can also be used as a standalone MS Excel model to estimate the storage system mass and volume outside of Framework and compare it to the DOE Technical Targets. This model will be explained and exercised with existing hydrogen storage materials.     

Design tool for estimating chemical hydrogen storage system characteristics for light-duty fuel cell vehicles

The U.S. Department of Energy (DOE) developed a vehicle Framework model to simulate fuel cell-based light-duty vehicle operation for various hydrogen storage systems. This transient model simulates the performance of the storage system, fuel cell, and vehicle for comparison to Technical Targets established by DOE for four drive cycles/profiles. Chemical hydrogen storage models have been developed for the Framework for both exothermic and endothermic materials. Despite the utility of such models, they require that material researchers input system design specifications that cannot be estimated easily. To address this challenge, a design tool has been developed that allows researchers to directly enter kinetic and thermodynamic chemical hydrogen storage material properties into a simple sizing module that then estimates system parameters required to run the storage system model. Additionally, the design tool can be used as a standalone executable file to estimate the storage system mass and volume outside of the Framework model. These models will be explained and exercised with the representative hydrogen storage materials exothermic ammonia borane (NH₃BH₃) and endothermic alane (AlH₃).     

Performance assessment of 700-bar compressed hydrogen storage for light duty fuel cell vehicles

Type 4 700-bar compressed hydrogen storage tanks were modeled using ABAQUS. The finite element model was first calibrated against data for 35-L subscale test tanks to obtain the composite translation efficiency, and then applied to full sized tanks. Two variations of the baseline T700/epoxy composite were considered in which the epoxy was replaced with a low cost vinyl ester resin and low cost resin with an alternate sizing. The results showed that the reduction in composite weight was attributed primarily to the lower density of the resin and higher fiber volume fraction in the composite due to increased squeeze-out with the lower viscosity vinyl ester resin. The system gravimetric and volumetric capacities for the onboard storage system that holds 5.6 kg H₂ are 4.2 wt% (1.40 kWh/kg) and 24.4 g-H₂/L (0.81 kWh/L), respectively. The system capacities increase and carbon fiber requirement decreases if the in-tank amount of unrecoverable hydrogen is reduced by lowering the tank “empty” pressure. Models of an alternate tank design showed potential 4–7% saving in composite usage for tanks with a length-to-diameter (L/D) ratio of 2.8–3.0 but no saving for L/D of 1.7. A boss with smaller opening and longer flange does not appear to reduce the amount of helical windings.     

Parametric investigations on LCC1 based hydrogen storage system intended for fuel cell applications

Considering the necessity for compact hydrogen storage system for fuel cell stacks, 41 embedded cooling tube (ECT) reactor with an outer cooling jacket (OCJ) is designed, fabricated and tested with 3.75 kg of LCC1® alloy. To analyse the sensitivity of the system performance at various operating conditions and the applicability of this prototype as storage system, an extensive parametric investigation was carried out at varying supply pressure (P_s), absorption temperature (T_a) and desorption temperature (T_d). LCC1® alloy achieved maximum hydrogen storage capacity (HSC) of 1.6 wt% within 420 s at P_s of 25 bar, T_a of 25 °C and heat transfer fluid (HTF) flow rate (HTF_a) of 6 LPM. Supply pressure is found to have greater influence than absorption temperature over absorption performance and heating output. With T_a of 25 °C, HTF_a of 6 LPM, HSC of 1.58 wt% and 1.6 wt% were achieved at P_s of 20 bar and 30 bar, respectively, resulting in corresponding specific heating power (SHP) of 497.7 W/kg and 544.9 W/kg. Varying T_a from 25 °C to 35 °C at P_s of 20 bar and HTF_a of 6 LPM resulted in 3% reduction in HSC. During desorption, desorption temperature of above 20 °C is found to be favourable with more than 95% of stored hydrogen being desorbed. It is further observed that the dehydriding rate of LCC1® was nearly steady which is potentially suitable for fuel cell applications, as the average dehydriding rate is estimated to be about 15.75 NLPM and 22.91 NLPM at T_d of 20 °C and 25 °C, respectively, with 6 LPM of HTF flow rate. The analysed module is proposed as a potential hydrogen supply unit for a 1 kW fuel cell reported in literature.     

A techno-economic analysis of decentralized electrolytic hydrogen production for fuel cell vehicles

Hydrogen from decentralized water electrolysis is one of the main fuelling options considered for future fuel cell vehicles. In this study, a model is developed to determine the key technical and economic parameters influencing the competitive position of decentralized electrolytic hydrogen. This model incorporates the capital, maintenance and energy costs of water electrolysis, as well as a monetary valuation of the associated greenhouse gas (GHG) emissions. It is used to analyze the competitive position of electrolytic hydrogen in three specific locations with distinct electricity mix: Vancouver, Los Angeles and Paris. Using local electricity prices and fuel taxes, electrolytic hydrogen is found to be commercially viable in Vancouver and Paris. Hydrogen storage comes out as the most important technical issue. But more than any technical issue, electricity prices and fuel taxes emerge as the two dominant issues affecting the competitive position of electrolytic hydrogen. The monetary valuation of GHG emissions, based on a price of $20/ton of CO₂, is found to be generally insufficient to tilt the balance in favor of electrolytic hydrogen.     

Metal hydride hydrogen storage tank for light fuel cell vehicle

We describe a metal hydride (MH) hydrogen storage tank for light fuel cell vehicle application developed at HySA Systems. A multi-component AB₂-type hydrogen storage alloy was produced by vacuum induction melting (10 kg per a load) at our industrial-scale facility. The MH alloy has acceptable H sorption performance, including reversible H storage capacity up to ∼170 NL/kg (1.5 wt% H). The cassette-type MH tank was made up of 2 cylindrical aluminium canisters with transversal internal copper fins and external aluminium fins for improving the heat exchange between the heating medium and the MH tank. Heat supply and removal was provided from the outside using air at T = 15–25 °C. The MH tank was tested at the conditions of natural or forced (velocity ∼2 m/s) air convection. The tests included H₂ charge of the tank at P = 15–40 bar and its discharge at P = 1 bar. The tank in the H₂ discharge mode was also tested together with open cathode low-temperature proton exchange membrane fuel cell (LT PEMFC).     

Integrated planning method of green hydrogen supply chain for hydrogen fuel cell vehicles

To satisfy the growing refueling demand of hydrogen fuel cell vehicles (HFCVs) with carbon-free hydrogen supply, this paper proposes an integrated planning method of green hydrogen supply chain. First, the k-shorted path method is introduced to analyze HFCV refueling load considering vehicle travel habits and routing diversity. Second, based on it, a two-stage integrated planning model is established to minimize the total investment and operation cost. The construction of hydrogen refueling stations, electrolysis-based hydrogen generation stations and hydrogen pipelines are coordinated with their operating constraints, constituting the green hydrogen supply chain, in which hydrogen storage is also an important part for consideration to address variable renewable power. Then, the proposed model is reformulated as a mixed integer linear programing (MILP) problem solved efficiently. Finally, the case studies are carried out on an urban area in Xi'an China to verify the validity and correctness of the proposed method. The results show that the integrated planning can realize synergy benefits. The influence of electricity prices and k values is also discussed.     

HYDRIDE4MOBILITY: An EU HORIZON 2020 project on hydrogen powered fuel cell utility vehicles using metal hydrides in hydrogen storage and refuelling systems

The goal of the EU Horizon 2020 RISE project 778307 “Hydrogen fuelled utility vehicles and their support systems utilising metal hydrides” (HYDRIDE4MOBILITY), is in addressing critical issues towards a commercial implementation of hydrogen powered forklifts using metal hydride (MH) based hydrogen storage and PEM fuel cells, together with the systems for their refuelling at industrial customers facilities. For these applications, high specific weight of the metallic hydrides has an added value, as it allows counterbalancing of a vehicle with no extra cost. Improving the rates of H₂ charge/discharge in MH on the materials and system level, simplification of the design and reducing the system cost, together with improvement of the efficiency of system “MH store-FC”, is in the focus of this work as a joint effort of consortium uniting academic teams and industrial partners from two EU and associated countries Member States (Norway, Germany, Croatia), and two partner countries (South Africa and Indonesia).The work within the project is focused on the validation of various efficient and cost-competitive solutions including (i) advanced MH materials for hydrogen storage and compression, (ii) advanced MH containers characterised by improved charge-discharge dynamic performance and ability to be mass produced, (iii) integrated hydrogen storage and compression/refuelling systems which are developed and tested together with PEM fuel cells during the collaborative efforts of the consortium.This article gives an overview of HYDRIDE4MOBILITY project focused on the results generated during its first phase (2017–2019).     

On-board and Off-board performance of hydrogen storage options for light-duty vehicles

Leading physical and materials-based hydrogen storage options are evaluated for their potential to meet the vehicular targets for gravimetric and volumetric capacity, cost, efficiency, durability and operability, fuel purity, and environmental health and safety. Our analyses show that hydrogen stored as a compressed gas at 350–700 bar in Type III or Type IV tanks cannot meet the near-term volumetric target of 28 g/L. The problems of dormancy and hydrogen loss with conventional liquid H₂ storage can be mitigated by deploying pressure-bearing insulated tanks. Alane (AlH₃) is an attractive hydrogen carrier if it can be prepared and used as a slurry with >50% solids loading and an appropriate volume-exchange tank is developed. Regenerating AlH₃ is a major problem, however, since it is metastable and it cannot be directly formed by reacting the spent Al with H₂. We have evaluated two sorption-based hydrogen storage systems, one using AX-21, a high surface-area superactivated carbon, and the other using MOF-177, a metal-organic framework material. Releasing hydrogen by hydrolysis of sodium borohydride presents difficult chemical, thermal and water management issues, and regenerating NaBH₄ by converting B–O bonds is energy intensive. We have evaluated the option of using organic liquid carriers, such as n-ethylcarbazole, which can be dehydrogenated thermolytically on-board a vehicle and rehydrogenated efficiently in a central plant by established methods and processes. While ammonia borane has a high hydrogen content, a solvent that keeps it in a liquid state needs to be found, and developing an AB regeneration scheme that is practical, economical and efficient remains a major challenge.     

Analysis of Ontario's hydrogen economy demands from hydrogen fuel cell vehicles

The ‘Hydrogen Economy’ is a proposed system where hydrogen is produced from carbon dioxide free energy sources and is used as an alternative fuel for transportation. The utilization of hydrogen to power fuel cell vehicles (FCVs) can significantly decrease air pollutants and greenhouse gases emission from the transportation sector. In order to build the future hydrogen economy, there must be a significant development in the hydrogen infrastructure, and huge investments will be needed for the development of hydrogen production, storage, and distribution technologies. This paper focuses on the analysis of hydrogen demand from hydrogen FCVs in Ontario, Canada, and the related cost of hydrogen. Three potential hydrogen demand scenarios over a long period of time were projected to estimate hydrogen FCVs market penetration, and the costs associated with the hydrogen production, storage and distribution were also calculated. A sensitivity analysis was implemented to investigate the uncertainties of some parameters on the design of the future hydrogen infrastructure. It was found that the cost of hydrogen is very sensitive to electricity price, but other factors such as water price, energy efficiency of electrolysis, and plant life have insignificant impact on the total cost of hydrogen produced.     

Y type zeolites/PI membranes for sulfur-free hydrogen source and for fuel cell applications

Sulfur removal is significant for fuels used as hydrogen source for modern fuel cell applications and to avoid sulfur poisoning of therein used catalysts. Novel membranes for the polymer–zeolite system with well-defined transport channels are proposed for the sulfur removal. Membranes are fabricated using polyimide (PI) as matrix material and Y zeolites as adsorptive functional materials. By detailed analysis of FT-IR, morphology and adsorption performance of membranes, the process-structure-function relationship is obtained. The results show that the functional zeolites particles are incorporated into three-dimensional channels. For all cases, the inlet fuel can be desulfurized to below 0.1 mg L⁻¹, which means that the outlet fuel can be used as sulfur-free hydrogen source for fuel cell applications. The proposed membranes adsorber may be applied as sulfur trap before the reformer for fuel cells on-board or on-site, and it may be applied in a periodically replaceable form. The desulfurization efforts by membrane are likely to play an influential role for the development of sulfur-free hydrogen source and fuel cell area.     

Design tool for estimating adsorbent hydrogen storage system characteristics for light-duty fuel cell vehicles

This work combines materials development with hydrogen storage technology advancements to address onboard hydrogen storage challenges in light-duty vehicle applications. These systems are comprised of the vehicle requirements design space, balance of plant requirements, storage system components, and materials engineering culminating in the development of an Adsorbent System Design Tool that serves as a preprocessor to the storage system and vehicle-level models created within the Hydrogen Storage Engineering Center of Excellence. Computational and experimental efforts were integrated to evaluate, design, analyze, and scale potential hydrogen storage systems and their supporting components against the Department of Energy 2020 and Ultimate Technical Targets for Hydrogen Storage Systems for Light Duty Vehicles. Ultimately, the Adsorbent System Design Tool was created to assist material developers in assessing initial design parameters that would be required to estimate the performance of the hydrogen storage system once integrated with the full fuel cell system.     

Fuel economy of hydrogen fuel cell vehicles

On the basis of on-road energy consumption, fuel economy (FE) of hydrogen fuel cell light-duty vehicles is projected to be 2.5–2.7 times the fuel economy of the conventional gasoline internal combustion engine vehicles (ICEV) on the same platforms. Even with a less efficient but higher power density 0.6 V per cell than the base case 0.7 V per cell at the rated power point, the hydrogen fuel cell vehicles are projected to offer essentially the same fuel economy multiplier. The key to obtaining high fuel economy as measured on standardized urban and highway drive schedules lies in maintaining high efficiency of the fuel cell (FC) system at low loads. To achieve this, besides a high performance fuel cell stack, low parasitic losses in the air management system (i.e., turndown and part load efficiencies of the compressor–expander module) are critical.     

Electrochemical hydrogen storage: Opportunities for fuel storage,batteries, fuel cells,and supercapacitors

Solid-state storage of hydrogen is a possible breakthrough to realise the unique futures of hydrogen as a green fuel. Among possible methods, electrochemical hydrogen storage is very promising, as can be conducted at low temperature and pressure with a simple device reversibly. However, it has been overshadowed by the physical hydrogen storage in the literature, and thus, research efforts are not adequately connected to lead us in the right direction. On the other hand, electrochemical hydrogen storage is the basis of some other electrochemical power sources such as batteries, fuel cells, and supercapacitors. For instance, available hydrogen storage materials can build supercapacitors with exceptionally high specific capacitance in order of 4000 F g^?1. In general, electrochemical hydrogen storage plays a substantial role in the future of not only hydrogen storage but also electrochemical power sources. There are some vague points which have obscured our understanding of the corresponding system to be developed practically. This review aims to portray the entire field and detect those ambiguous points which are indeed the key obstacles. It is clarified that different materials have somehow similar mechanisms for electrochemical hydrogen storage, which is initiated by hydrogen dissociation, surface adsorption and probably diffusing deep within the bulk material. This mechanism is different from the insertion/extraction of alkali metals, though battery materials look similar. Based on the available reports, it seems that the most promising material design for the future of electrochemical hydrogen storage is a class of subtly designed nanocomposites of Mg-based alloys and mesoporous carbons.