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H-Mat Hydrogen Compatibility of NBR Elastomers
Sep 2021
Publication
The H2@Scale program of the U.S. Department of Energy (DOE) Hydrogen and Fuel Cell Technologies Office (HFTO) is supporting work on the hydrogen compatibility of polymers to improve the durability and reliability of materials for hydrogen infrastructure. The hydrogen compatibility program (H-Mat) seeks “to address the challenges of hydrogen degradation by elucidating the mechanisms of hydrogen-materials interactions with the goal of providing science-based strategies to design materials (micro)structures and morphology with improved resistance to hydrogen degradation.” Previous work on ethylene propylene diene indicated hydrogen interaction with plasticizer increased its migration to the surface and coalescing within the elastomer compound. New research on nitrile butadiene (NBR) has found hydrogen and pressure interactions with a series model rubber-material compounds to behave similarly in some compounds and improved in other compounds that is demonstrated through volume change and compression-set differences in the materials. Further studies were conducted using a helium-ion microscope (HeIM) which revealed significant morphological changes in the plasticizer-incorporating compounds after static exposure and pressure cycling as evidenced by time-of-flight secondary ion mass spectrometry. Additional studies using x-ray chromatography revealed that more micro-voids/-cracks developed after gas decompression in unfilled materials than in filled materials; transmission electron microscopy (TEM) probed at the nano-meter level showing change in filler distribution and morphology around Zinc-based particles.
Role of Hydrogen-based Energy Carriers as an Alternative Option to Reduce Residual Emissions Associated with Mid-century Decarbonization Goals
Mar 2022
Publication
Hydrogen-based energy carriers including hydrogen ammonia and synthetic hydrocarbons are expected to help reduce residual carbon dioxide emissions in the context of the Paris Agreement goals although their potential has not yet been fully clarified in light of their competitiveness and complementarity with other mitigation options such as electricity biofuels and carbon capture and storage (CCS). This study aimed to explore the role of hydrogen in the global energy system under various mitigation scenarios and technology portfolios using a detailed energy system model that considers various energy technologies including the conversion and use of hydrogen-based energy carriers. The results indicate that the share of hydrogen-based energy carriers generally remains less than 5% of global final energy demand by 2050 in the 2 ◦C scenarios. Nevertheless such carriers contribute to removal of residual emissions from the industry and transport sectors under specific conditions. Their share increases to 10–15% under stringent mitigation scenarios corresponding to 1.5 ◦C warming and scenarios without CCS. The transport sector is the largest consumer accounting for half or more of hydrogen production followed by the industry and power sectors. In addition to direct usage of hydrogen and ammonia synthetic hydrocarbons converted from hydrogen and carbon captured from biomass or direct air capture are attractive transport fuels growing to half of all hydrogen-based energy carriers. Upscaling of electrification and biofuels is another common cost-effective strategy revealing the importance of holistic policy design rather than heavy reliance on hydrogen.
Everything About Hydrogen Podcast: High-temperature Fuel Cells at High Altitudes
Jun 2021
Publication
HyPoint led by its CEO and co-founder Alex Ivanenko is at the cutting edge of the industry's efforts to find zero-emissions aircraft propulsion systems that do not sacrifice speed and power in the name of sustainability. HyPoint is a leading producer of high-temperature PEM fuel cells for aviation applications including for logistic drones air taxis electric vertical takeoff and landing vehicles (eVTOLs) and fixed-wing airplanes. On this episode of the EAH podcast the team speaks with Alex about the incredible pace of development and rapid innovation that he and his colleagues are driving in the hydrogen aviation space and how his company is leading the way in a highly complex and competitive race to decarbonize modern air travel.
The podcast can be found on their website
The podcast can be found on their website
An Experimental Study of Propagating Spherical Flames in Unconfined Hydrogen-oxygen Explosions
Sep 2021
Publication
The study to understand the flame propagation behaviors of hydrogen-oxygen explosions is required to make a precise risk assessment. Moreover although research has investigated the propagating spherical flames in unconfined hydrogen-air explosions no study to date has examined the hydrogen-oxygen explosions. The spherical flame propagation in unconfined hydrogen-oxygen explosions have been investigated using a soap bubble method. In the present experiments hydrogen-oxygen mixtures were filled in a 10 cm diameter soap bubble and ignited by an electric spark at the center. The flame propagation behaviors were measured by a high-speed Schlieren photography. The laminar burning velocities and critical flame radii for the onset of flame acceleration in unconfined hydrogen-oxygen explosions were estimated. Results demonstrated that the laminar burning velocities of hydrogenoxygen mixtures were much faster than those of hydrogen-air mixtures. In addition the shift value of maximum laminar burning velocity for hydrogen-oxygen mixtures towards a leaner equivalence ratio is observed. The experimental flame speeds for all experiments were increased owing to diffusionalthermal and Darrieus-Landau instabilities although the measured flame radii were small. The critical flame radius corresponding to the onset of flame acceleration decreased with the decrease in equivalence ratio.
Numerical Simulation of Hydrogen Leakage from Fuel Cell Vehicle in an Outdoor Parking Garage
Aug 2021
Publication
It is significant to assess the hydrogen safety of fuel cell vehicles (FCVs) in parking garages with a rapidly increased number of FCVs. In the present work a Flame Acceleration Simulator (FLACS) a computational fluid dynamics (CFD) module using finite element calculation was utilized to predict the dispersion process of flammable hydrogen clouds which was performed by hydrogen leakage from a fuel cell vehicle in an outdoor parking garage. The effect of leakage diameter (2 mm 3 mm and 4 mm) and parking configurations (vertical and parallel parking) on the formation of flammable clouds with a range of 4–75% by volume was considered. The emission was assumed to be directed downwards from a Thermally Activated Pressure Relief Device (TPRD) of a 70 MPa storage tank. The results show that the 0.7 m parking space stipulated by the current regulations is less than the safety space of fuel cell vehicles. Compared with a vertical parking configuration it is safer to park FCVs in parallel. It was also shown that release through a large TPRD orifice should be avoided as the proportion of the larger hydrogen concentration in the whole flammable domain is prone to more accidental severe consequences such as overpressure.
Current Research Progress in Magnesium Borohydride for Hydrogen Storage (A review)
Nov 2021
Publication
Hydrogen storage in solid-state materials is believed to be a most promising hydrogen-storage technology for high efficiency low risk and low cost. Mg(BH4)2 is regarded as one of most potential materials in hydrogen storage areas in view of its high hydrogen capacities (14.9 wt% and 145–147 kg cm3 ). However the drawbacks of Mg(BH4)2 including high desorption temperatures (about 250 C–580 C) sluggish kinetics and poor reversibility make it difficult to be used for onboard hydrogen storage of fuel cell vehicles. A lot of researches on improving the dehydrogenation reaction thermodynamics and kinetics have been done mainly including: additives or catalysts doping nanoconfining Mg(BH4)2 in nanoporous hosts forming reactive hydrides systems multi-cation/anion composites or other derivatives of Mg(BH4)2. Some favorable results have been obtained. This review provides an overview of current research progress in magnesium borohydride including: synthesis methods crystal structures decomposition behaviors as well as emphasized performance improvements for hydrogen storage.
How to Give a renewed Chance to Natural Gas as Feed for the Production of Hydrogen: Electric MSR Coupled with CO2 Mineralization
Sep 2021
Publication
Recent years have seen a growing interest in water electrolysis as a way to store renewable electric energy into chemical energy through hydrogen production. However today the share of renewable energy is still limited and there is the need to have a continuous use of H2 for industrial chemicals applications. Firstly the paper discusses the use of electrolysis - connected to a conventional grid - for a continuous H2 production in terms of associated CO2 emissions and compares such emissions with conventional methane steam reforming (MSR). Therefore it explores the possibility to use electrical methane steam reforming (eMSR) as a way to reduce the CO2 emissions. As a way to have zero emissions carbon mineralization of CO2 is coupled - instead of in-situ carbon capture and storage technology (CCS) - to eMSR; associated relevant cost of production is evaluated for different scenarios. It appears that to minimize such production cost carbonate minerals must be reused in the making of other industrial products since the amount of carbonates generated by the process is quite significant.
How to Decarbonise the UKs Freight Sector by 2050
Dec 2020
Publication
To achieve the UK’s net zero target vehicles including heavy-duty vehicles (HDVs) will need to be entirely decarbonised. The UK government has announced that it plans to phase out the sale of all new cars and vans with engines between 2030 and 2035. It has also announced its intention to consult on a similar phase-out for diesel-powered heavy-goods vehicles (HGVs). This study analyses policies and technologies which can contribute to the decarbonisation of the UK's inland freight sector.
It comprises an emissions modelling exercise and a cost analysis for total cost of ownership (TCO) of long-haul trucks. The study shows that for urban and regional deliveries battery electric trucks offer the best option to decarbonise. It also shows that battery electric trucks and those using an overhead catenary infrastructure are likely to be the most cost-effective pathway to decarbonise long-haul trucks by 2050 but that renewable hydrogen could also be an option.
Link to Document Download on Transport & Environment website
It comprises an emissions modelling exercise and a cost analysis for total cost of ownership (TCO) of long-haul trucks. The study shows that for urban and regional deliveries battery electric trucks offer the best option to decarbonise. It also shows that battery electric trucks and those using an overhead catenary infrastructure are likely to be the most cost-effective pathway to decarbonise long-haul trucks by 2050 but that renewable hydrogen could also be an option.
Link to Document Download on Transport & Environment website
Electrical Double Layer Mechanism Analysis of PEM Water Electrolysis for Frequency Limitation of Pulsed Currents
Nov 2021
Publication
This paper proposes a method for improving hydrogen generation using pulse current in a proton exchange membrane-type electrolyzer (PEMEL). Traditional methods of electrolysis using direct current are known as the simplest approach to produce hydrogen. However it is highly dependent on environmental variables such as the temperature and catalyst used to enhance the rate of electrolysis. Therefore we propose electrolysis using a pulse current that can apply several dependent variables rather than environmental variables. The proposed method overcomes the difficulties in selecting the frequency of the pulse current by deriving factors affecting hydrogen generation while changing the concentration generated by the cell interface during the pulsed water-electrolysis process. The correlation between the electrolyzer load and the frequency characteristics was analyzed and the limit value of the applicable frequency of the pulse current was derived through electrical modeling. In addition the operating characteristics of PEMEL could be predicted and the PEMEL using the proposed pulse current was verified through experiments.
Everything About Hydrogen Podcast: Toyota's global hydrogen ambitions
Feb 2020
Publication
On this weeks episode the team are talking all things hydrogen with Craig Scott the Group Manager for Toyota North America a global automotive giant and a recognised pioneer in the field of fuel cell mobility. On the show we get into the story of Toyota’s roll out of fuel cell mobility solutions in North America the challenges and opportunities that fuel cell vehicles can offer in the hydrogen market and the challenges around infrastructure. Importantly we also dive into the scaling up work that Toyota is undertaking and some of its plans for next steps on the mission to become the world’s leader in fuel cell mobility solutions. All this and more on the show!
The podcast can be found on their website
The podcast can be found on their website
Law and Policy Review on Green Hydrogen Potential in ECOWAS Countries
Mar 2022
Publication
This paper aims to review existing energy-sector and hydrogen-energy-related legal policy and strategy documents in the ECOWAS region. To achieve this aim current renewable-energyrelated laws acts of parliament executive orders presidential decrees administrative orders and memoranda were analyzed. The study shows that ECOWAS countries have strived to design consistent legal instruments regarding renewable energy in developing comprehensive legislation and bylaws to consolidate it and to encourage investments in renewable energy. Despite all these countries having a legislative basis for regulating renewable energy there are still weaknesses that revolve around the law and policy regarding its possible application in green hydrogen production and use. The central conclusion of this review paper is that ECOWAS member states presently have no official hydrogen policies nor bylaws in place. The hydrogen rise presents a challenge and opportunity for members to play an important role in the fast-growing global hydrogen market. Therefore these countries need to reform their regulatory frameworks and align their policies by introducing green hydrogen production in order to accomplish their green economy transition for the future and to boost the continent’s sustainable development.
Everything About Hydrogen Podcast: Flying Hy!
Feb 2021
Publication
Decarbonizing aviation is a big challenge. It is one of the most carbon intensive business sectors in the modern world and change comes slowly to the aviation industry. Hydrogen and fuel cell technologies offer a pathway to decarbonize regional flights in the not-so-distant future and big names are looking at potential solutions for long-haul flights in the longer term. But even if we build the aircraft that can use hydrogen as a fuel how do we get the fuel to them in a timely reliable and cost-efficient way?
The podcast can be found on their website
The podcast can be found on their website
The Implications of Ambitious Decarbonisation of Heat and Road Transport for Britain’s Net Zero Carbon Energy Systems
Oct 2021
Publication
Decarbonisation of heating and road transport are regarded as necessary but very challenging steps on the pathway to net zero carbon emissions. Assessing the most efficient routes to decarbonise these sectors requires an integrated view of energy and road transport systems. Here we describe how a national gas and electricity transmission network model was extended to represent multiple local energy systems and coupled with a national energy demand and road transport model. The integrated models were applied to assess a range of technologies and policies for heating and transport where the UK’s 2050 net zero carbon emissions target is met. Overall annual primary energy use is projected to reduce by between 25% and 50% by 2050 compared to 2015 due to ambitious efficiency improvements within homes and vehicles. However both annual and peak electricity demands in 2050 are more than double compared with 2015. Managed electric vehicle charging could save 14TWh/year in gas-fired power generation at peak times and associated emissions whilst vehicle-to-grid services could provide 10GW of electricity supply during peak hours. Together managed vehicle charging and vehicle-to-grid supplies could result in a 16% reduction in total annual energy costs. The provision of fast public charging facilities could reduce peak electricity demand by 17GW and save an estimated £650 million annually. Although using hydrogen for heating and transport spreads the hydrogen network costs between homeowners and motorists it is still estimated to be more costly overall compared to an all-electric scenario. Bio-energy electricity generation plants with carbon capture and storage are required to drive overall energy system emissions to net zero utilisation of which is lowest when heating is electrified and road transport consists of a mix of electric and hydrogen fuel-cell vehicles. The analysis demonstrates the need for an integrated systems approach to energy and transport policies and for coordination between national and local governments.
Everything About Hydrogen Podcast: Building Hydrogen Infrastructure with Black & Veatch
Feb 2020
Publication
On this weeks episode the team are talking all things hydrogen with Maryline Daviaud Lewett Director of Business Development for Transformative Technologies at Black & Veatch (B&V). On the show we discuss the role that Engineering Procurement and Construction (EPC) firms are playing in developing hydrogen and fuel cell infrastructure as well as discussing the unique aspects of developing projects in North America. As the leading EPC for hydrogen refuelling stations in North America and a wealth of experience across electric vehicle charging and hydrogen Maryline brings a uniquely well rounded perspective to the discussion and shares a wealth of insights for how the market may evolve. All this and more on the show!
The podcast can be found on their website
The podcast can be found on their website
Life Cycle Assessment and Water Footprint of Hydrogen Production Methods: From Conventional to Emerging Technologies
Oct 2020
Publication
A common sustainability issue arising in production systems is the efficient use of resources for providing goods or services. With the increased interest in a hydrogen (H2) economy the life-cycle environmental performance of H2 production has special significance for assisting in identifying opportunities to improve environmental performance and to guide challenging decisions and select between technology paths. Life cycle impact assessment methods are rapidly evolving to analyze multiple environmental impacts of the production of products or processes. This study marks the first step in developing process-based streamlined life cycle analysis (LCA) of several H2 production pathways combining life cycle impacts at the midpoint (17 problem-oriented) and endpoint (3 damage-oriented) levels using the state-of-the-art impact assessment method ReCiPe 2016. Steam reforming of natural gas coal gasification water electrolysis via proton exchange membrane fuel cell (PEM) solid oxide electrolyzer cell (SOEC) biomass gasification and reforming and dark fermentation of lignocellulosic biomass were analyzed. An innovative aspect is developed in this study is an analysis of water consumption associated with H2 production pathways by life-cycle stage to provide a better understanding of the life cycle water-related impacts on human health and natural environment. For water-related scope Water scarcity footprint (WSF) quantified using Available Water Remaining (AWARE) method was applied as a stand-alone indicator. The paper discusses the strengths and weaknesses of each production pathway identify the drivers of environmental impact quantify midpoint environmental impact and its influence on the endpoint environmental performance. The findings of this study could serve as a useful theoretical reference and practical basis to decision-makers of potential environmental impacts of H2 production systems.
Evaluating the Opportunity to Repurpose Gas Transmission Assets for Hydrogen Transportation
Sep 2021
Publication
The UK National Transmission System (NTS) is a key enabler to decarbonise the gas network in Great Britain (GB) in order to meet the UK government’s target of net-zero emissions by 2050. FutureGrid is National Grid’s research programme assessing the capability of the transmission system to transport hydrogen. Our goal is to accelerate the decarbonisation of power industry and heat by delivering a safe supply of energy to all customers both during and after the energy transition. FutureGrid will lead to a better understanding of what the technical parameters are around the ultimate role of the NTS in the energy system and how the transition can be managed. Under FutureGrid National Grid will construct a NTS hydrogen test facility at DNV’s Spadeadam testing and research site. NTS assets due to be decommissioned in early RIIO2 will be reconstructed to create a test network that can be used to answer some of the fundamental questions around safety and operation of a converted network. Flows of hydrogen/natural gas blends including 100% hydrogen will be tested for the first time in GB at transmission pressures. This system will connect to the existing H21 distribution network test facility at Spadeadam to prove a complete beach-to-meter network can be decarbonised to develop a comprehensive programme for the hydrogen transition. The project will provide a transmission facility which is a key enabler for more advanced hydrogen testing on industrial equipment such as hydrogen separation technology hydrogen compressors and/or purification of hydrogen for transport. Our paper will detail the current position and aims of the project.
Liquid Hydrogen as Prospective Energy Carrier: A Brief Review and Discussion of Underlying Assumptions Applied in Value Chain Analysis
Nov 2021
Publication
In the literature different energy carriers are proposed in future long-distance hydrogen value chains. Hydrogen can be stored and transported in different forms e.g. as compressed dense-phase hydrogen liquefied hydrogen and in chemically bound forms as different chemical hydrides. Recently different high-level value chain studies have made extrapolative investigations and compared such options with respect to energy efficiency and cost. Three recent journal papers overlap as the liquid hydrogen option has been considered in all three studies. The studies are not fully aligned in terms of underlying assumptions and battery limits. A comparison reveals partly vast differences in results for chain energy efficiency for long-distance liquid hydrogen transport which are attributable to distinct differences in the set of assumptions. Our comparison pinpoints the boiloff ratio i.e. evaporation losses due to heat ingress in liquid hydrogen storage tanks as the main cause of the differences and this assumption is further discussed. A review of spherical tank size and attributed boiloff ratios is presented for existing tanks of different vintage as well as for recently proposed designs. Furthermore the prospect for further extension of tanks size and reduction of boiloff ratio is discussed with a complementary discussion about the use of economic assumptions in extrapolative and predictive studies. Finally we discuss the impact of battery limits in hydrogen value chain studies and pinpoint knowledge needs and the need for a detailed bottom-up approach as a prerequisite for improving the understanding for pros and cons of the different hydrogen energy carriers.
Oxygen Carriers for Chemical-looping Water Splitting to Hydrogen Production: A Critical Review
Oct 2021
Publication
Chemical looping water splitting (CLWS) process using metal oxides or perovskites as oxygen carriers (OCs) is capable of producing pure H2 in an efficient simple and flexible way. The OCs are first reduced by hydrocarbon fuels and then oxidized by steam in a cyclic way. After the condensation of the gaseous mixture of steam and H2 from the oxidation step pure H2 is obtained. In recent years great efforts for CLWS have been made to improve the redox activity and stability of OCs. In this paper the development of the OCs for hydrogen production from CLWS were discussed. Effects of supports and additives on the performances of OCs were compared based on redox reactions in CLWS. Fe-based OCs with CeO2 Al2O3 ZrO2 CuO MoO3 Rh etc. are very attractive for the CLWS process. Issues and challenges for the development of OCs were analyzed.
Review of Hydrogen Production Techniques from Water Using Renewable Energy Sources and Its Storage in Salt Caverns
Feb 2022
Publication
Hydrogen is becoming an increasingly important energy carrier in sector integration for fuel cell transportation heat and electricity. Underground salt caverns are one of the most promising ways to store the hydrogen obtained from water electrolysis using power generation from renewable energy sources (RES). At the same time the production of hydrogen can be used to avoid energy curtailments during times of low electricity demand or low prices. The stored hydrogen can also be used during times of high energy demand for power generation e.g. with fuel cells to cover the fluctuations and shortages caused by low RES generation. This article presents an overview of the techniques that were used and proposed for using excess energy from RES for hydrogen production from water and its storage techniques especially in underground salt caverns for the aforementioned purpose and its feasibility. This paper compares and summarizes the competing technologies based on the current state-of-the-art identifies some of the difficulties in hydrogen production and storage and discusses which technology is the most promising. The related analysis compares cost and techno-economic feasibility with regard to hydrogen production and storage systems. The paper also identifies the potential technical challenges and the limitations associated with hydrogen integration into the power grid.
Hydrogen Diffusion and Its Effect on Hydrogen Embrittlement in DP Steels with Different Martensite Content
Dec 2020
Publication
The hydrogen diffusion behavior and hydrogen embrittlement susceptibility of dual phase (DP) steels with different martensite content were investigated using the slow strain-rate tensile test and hydrogen permeation measurement. Results showed that a logarithmic relationship was established between the hydrogen embrittlement index (IHE) and the effective hydrogen diffusion coefficient (Deff). When the martensite content is low ferrite/ martensite interface behaves as the main trap that captures the hydrogen atoms. Also when the Deff decreases IHE increases with increasing martensite content. However when the martensite content reaches approximately 68.3% the martensite grains start to form a continuous network Deff reaches a plateau and IHE continues to increase. This is mainly related to the reduction of carbon content in martensite and the length of ferrite/martensite interface which promotes the diffusion of hydrogen atoms in martensite and the aggregation of hydrogen atoms at the ferrite/martensite interface. Finally a model describing the mechanism of microstructure-driven hydrogen diffusion with different martensite distribution was established.
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