United States
Fracture Properties of Welded 304L in Hydrogen Environments
Sep 2021
Publication
Austenitic stainless steels are used for hydrogen containment of high-pressure hydrogen gas due to their ability to retain high fracture properties despite the degradation due to hydrogen. Forging and other strain-hardening processes are desirable for austenitic stainless steels to increase the material strength and thus accommodate higher stresses and reduce material costs. Welding is often necessary for assembling components but it represents an area of concern in pressure containment structures due to the potential for defects more environmentally susceptible microstructure and reduced strength. Electron beam (EB) welding represent an advanced joining process which has advantages over traditional arc welding techniques through reduced input heat and reduced heat-affected zone (HAZ) microstructure and thus present a means to maintain high strength and improve weld performance in hydrogen gas containment. In this study fracture coupons were extracted from EB welds in forged 304L and subjected to thermal gaseous hydrogen precharging at select pressures to introduce different levels of internal hydrogen content. Fracture tests were then performed on hydrogen precharged coupons at temperatures of both 293 K and 223 K. It was observed that fracture resistance (JH) was dependent on internal hydrogen concentration; higher hydrogen concentrations resulted in lower fracture resistance in both the forged 304L base material and the 304L EB welds. This trend was also apparent at both temperatures: 293 K and 223 K. EB weld samples however maintain high fracture resistance comparable to the forged 304L base material. The role of weld microstructure solidification on fracture is discussed.
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
Total Cost of Ownership Analysis of Fuel Cell Electric Bus with Different Hydrogen Supply Alternatives
Dec 2023
Publication
In the transition to sustainable public transportation with zero-emission buses hydrogen fuel cell electric buses have emerged as a promising alternative to traditional diesel buses. However assessing their economic viability is crucial for widespread adoption. This study carries out a comprehensive examination encompassing both sensitivity and probabilistic analyses to assess the total cost of ownership (TCO) for the bus fleet and its corresponding infrastructure. It considers various hydrogen supply options encompassing on-site electrolysis on-site steam methane reforming and off-site hydrogen procurement with both gaseous and liquid delivery methods. The analysis covers critical cost elements encompassing bus acquisition costs infrastructure capital expenses and operational and maintenance costs for both buses and infrastructure. This paper conducted two distinct case studies: one involving a current small bus fleet of five buses and another focusing on a larger fleet set to launch in 2028. For the current small fleet the off-site gray hydrogen purchase with a gaseous delivery option is the most cost-effective among hydrogen alternatives but it still incurs a 26.97% higher TCO compared to diesel buses. However in the case of the expanded 2028 fleet the steam methane-reforming method without carbon capture emerges as the most likely option to attain the lowest TCO with a high probability of 99.5%. Additionally carbon emission costs were incorporated in response to the growing emphasis on environmental sustainability. The findings indicate that although diesel buses currently represent the most economical option in terms of TCO for the existing small fleet steam methane reforming with carbon capture presents a 69.2% likelihood of being the most cost-effective solution suggesting it is a strong candidate for cost efficiency for the expanded 2028 fleet. Notably substantial investments are required to increase renewable energy integration in the power grid and to enhance electrolyzer efficiency. These improvements are essential to make the electrolyzer a more competitive alternative to steam methane reforming. Overall the findings in this paper underscore the substantial impact of the hydrogen supply chain and carbon emission costs on the TCO of zero-emission buses.
Mitigating Emissions in the Global Steel Industry: Representing CCS and Hydrogen Technologies in Integrated Assessment Modelling
Dec 2023
Publication
We conduct a techno-economic assessment of two low-emissions steel production technologies and evaluate their deployment in emissions mitigation scenarios utilizing the MIT Economic Projection and Policy Analysis (EPPA) model. Specifically we assess direct reduced iron-electric arc furnace with carbon capture and storage (DRI-EAF with CCS) and H2-based direct reduced iron-electric arc furnace (H2 DRI-EAF) which utilizes low carbon hydrogen to reduce CO2 emissions. Our techno-economic analysis based on the current state of technologies found that DRI-EAF with CCS increased costs ~7% relative to the conventional steel technology. H2 DRI-EAF increased costs by ~18% when utilizing Blue hydrogen and ~79% when using Green hydrogen. The exact pathways for hydrogen production in different world regions including the extent of CCS and hydrogen deployment in steelmaking are highly speculative at this point. In illustrative scenarios using EPPA we find that using base cost assumptions switching from BF-BOF to DRI-EAF or scrap EAF can provide significant emissions mitigation within steelmaking. With further reductions in the cost of advanced steelmaking we find a greater role for DRI-EAF with CCS whereas reductions in both the cost of advanced steelmaking and hydrogen production lead to a greater role for H2 DRI-EAF. Our findings can be used to help decision-makers assess various decarbonization options and design economically efficient pathways to reduce emissions in the steel industry. Our cost evaluation can also be used to inform other energy-economic and integrated assessment models designed to provide insights about future decarbonization pathways.
Alternative-energy-vehicles Deployment Delivers Climate, Air Quality, and Health Co-benefits when Coupled with Decarbonizing Power Generation in China
Aug 2021
Publication
China is the world’s largest carbon emitter and suffers from severe air pollution which results in approximately one million premature deaths/year. Alternative energy vehicles (AEVs) (electric hydrogen fuel cell and natural gas vehicles) can reduce carbon emissions and improve air quality. However climate air quality and health benefits of AEVs powered with deeply decarbonized power generation are poorly quantified. Here we quantitatively estimate the air quality health carbon emission and economic benefits of replacing internal combustion engine vehicles with various AEVs. We find co-benefits increase dramatically as the electricity grid decarbonizes and hydrogen is produced from non-fossil fuels. Relative to 2015 a conversion to AEVs using largely non-fossil power can reduce air pollution and associated premature mortalities and years of life lost by 329000 persons/year and 1611000 life years/year. Thus maximizing climate air quality and health benefits of AEV deployment in China requires rapid decarbonization of the power system.
Influence of Cs Promoter on Ethanol Steam-Reforming Selectivity of Pt/m-ZrO2 Catalysts at Low Temperature
Sep 2021
Publication
The decarboxylation pathway in ethanol steam reforming ultimately favors higher selectivity to hydrogen over the decarbonylation mechanism. The addition of an optimized amount of Cs to Pt/m-ZrO2 catalysts increases the basicity and promotes the decarboxylation route converting ethanol to mainly H2 CO2 and CH4 at low temperature with virtually no decarbonylation being detected. This offers the potential to feed the product stream into a conventional methane steam reformer for the production of hydrogen with higher selectivity. DRIFTS and the temperature-programmed reaction of ethanol steam reforming as well as fixed bed catalyst testing revealed that the addition of just 2.9% Cs was able to stave off decarbonylation almost completely by attenuating the metallic function. This occurs with a decrease in ethanol conversion of just 16% relative to the undoped catalyst. In comparison with our previous work with Na this amount is—on an equivalent atomic basis—just 28% of the amount of Na that is required to achieve the same effect. Thus Cs is a much more efficient promoter than Na in facilitating decarboxylation.
Greenhouse Gas Emissions of Conventional and Alternative Vehicles: Predictions Based on Energy Policy Analysis in South Korea
Mar 2020
Publication
This paper compares the well-to-wheel (WTW) greenhouse gas (GHG) emissions of representative vehicle types–internal combustion engine vehicle (ICEV) hybrid electric vehicle (HEV) plug-in hybrid electric vehicle (PHEV) battery electric vehicle (BEV) and fuel cell electric vehicle (FCEV)–in the future (2030) based on a WTW analysis for the present (2017) and an analysis of various energy policies that could affect future emissions. South Korea was selected as the target region because it has detailed energy policies related to alternative vehicles. The WTW analysis for the present was performed based on three sets of subordinate analyses: (1) life cycle analyses of eight base fuels; (2) life cycle analyses of electricity and hydrogen; and (3) analyses of the fuel economies of seven vehicle types. From the WTW analysis for the present the national average WTW GHG emissions of ICEV-gasoline ICEV-diesel ICEV-liquefied petroleum gas HEV PHEV BEV and FCEV were calculated as 225 233 201 159 133 109 and 55 g-CO2-eq./km respectively. For calculating the WTW GHG emissions in the future two policies regarding electricity production and three policies regarding hydrogen production were analysed. Three cases with varying the degrees of improvements in fuel economies were considered. Six future scenarios were constructed and each scenario represented the case in which each energy policy is enacted. In the reference scenario for compact car the WTW GHG emissions of ICEVs-gasoline HEV PHEV BEV-200 mile FCEV were analysed as 161 110 97 86 and 91 g-CO2-eq./km respectively. The differences between ICEV/HEV and BEV were predicted to decrease in the future mainly due to larger improvements of ICEV/HEV in fuel economies compared to that of BEV. The future life cycle GHG emissions of electricity and hydrogen were calculated according to energy policy. Both two policies regarding power generation were confirmed to increase the benefits of utilizing BEVs but current energy policy regarding hydrogen production were confirmed to decrease the benefits of utilizing FCEVs. Based on the comprehensive results of this study a framework was proposed to evaluate the impacts of an energy policy regarding electricity and hydrogen production on the benefits of using BEVs and FCEVs compared to using HEVs and ICEVs. This framework can also be utilized in other countries when they assess and establish their energy policies.
Analysis of Trends and Emerging Technologies in Water Electrolysis Research Based on a Computational Method: A Comparison with Fuel Cell Research
Feb 2018
Publication
Water electrolysis for hydrogen production has received increasing attention especially for accumulating renewable energy. Here we comprehensively reviewed all water electrolysis research areas through computational analysis using a citation network to objectively detect emerging technologies and provide interdisciplinary data for forecasting trends. The results show that all research areas increase their publication counts per year and the following two areas are particularly increasing in terms of number of publications: “microbial electrolysis” and “catalysts in an alkaline water electrolyzer (AWE) and in a polymer electrolyte membrane water electrolyzer (PEME).”. Other research areas such as AWE and PEME systems solid oxide electrolysis and the whole renewable energy system have recently received several review papers although papers that focus on specific technologies and are cited frequently have not been published within the citation network. This indicates that these areas receive attention but there are no novel technologies that are the center of the citation network. Emerging technologies detected within these research areas are presented in this review. Furthermore a comparison with fuel cell research is conducted because water electrolysis is the reverse reaction to fuel cells and similar technologies are employed in both areas. Technologies that are not transferred between fuel cells and water electrolysis are introduced and future water electrolysis trends are discussed.
CFD Modeling and Consequence Analysis of an Accidental Hydrogen Release in a Large Scale Facility
Sep 2013
Publication
In this study the consequences of an accidental release of hydrogen within large scale (>15000 m3) facilities were modelled. To model the hydrogen release an LES Navier–Stokes CFD solver called fireFoam was used to calculate the dispersion and mixing of hydrogen within a large scale facility. The performance of the CFD modelling technique was evaluated through a validation study using experimental results from a 1/6 scale hydrogen release from the literature and a grid sensitivity study. Using the model a parametric study was performed varying release rates and enclosure sizes and examining the concentrations that develop. The hydrogen dispersion results were then used to calculate the corresponding pressure loads from hydrogen-air deflagrations in the facility.
Review of Release Behavior of Hydrogen & Natural Gas Blends from Pipelines
Aug 2021
Publication
Hydrogen can be used to reduce carbon emissions by blending into other gaseous energy carriers such as natural gas. However hydrogen blending into natural gas has important implications for safety which need to be evaluated. Hydrogen has different physical properties than natural gas and these properties affect safety evaluations concerning a leak of the blended gas. The intent of this report is to begin to investigate the safety implications of blending hydrogen into the natural gas infrastructure with respect to a leak event from a pipeline. A literature review was conducted to identify existing data that will better inform future hazard and risk assessments for hydrogen/natural gas blends. Metrics with safety implications such as heat flux and dispersion behavior may be affected by the overall blend ratio of the mixture. Of the literature reviewed there was no directly observed separation of the hydrogen from the natural gas or methane blend. No literature was identified that experimentally examined unconfined releases such as concentration fields or concentration at specific distances. Computational efforts have predicted concentration fields by modified versions of existing engineering models but the validation of these models is limited by the unavailability of literature data. There are multiple literature sources that measured flame lengths and heat flux values which are both relevant metrics to risk and hazard assessments. These data can be more directly compared to the outputs of existing engineering models for validation.
The paper can be downloaded on their website
The paper can be downloaded on their website
Everything About Hydrogen Podcast: The year-end Round Up! 2020 in Review
Dec 2020
Publication
2020 has been a year for the history books! Some good most of it not so good; but 2020 has been a boom year for the future of hydrogen technologies. Patrick Chris and Andrew do their level best on this episode to talk about all the stories and the highlights of 2020 in under 50 minutes. Have a listen and let us know if we missed anything in our penultimate episode of 2020!
The podcast can be found on their website
The podcast can be found on their website
The Future of Clean Hydrogen in the United States: Views from Industry, Market Innovators, and Investors
Sep 2021
Publication
This report The Future of Clean Hydrogen in the United States: Views from Industry Market Innovators and Investors sheds light on the rapidly evolving hydrogen market based on 72 exploratory interviews with organizations across the current and emerging hydrogen value chain. This report is part of a series From Kilograms to Gigatons: Pathways for Hydrogen Market Formation in the United States which will build on this study to evaluate policy opportunities for further hydrogen development in the United States. The goal of the interviews was to provide a snapshot of the clean hydrogen investment environment and better understand organizations’ market outlook investment rationale and areas of interest. This interview approach was supported by traditional research methods to contextualize and enrich the qualitative findings. This report should be understood as input to a more extensive EFI analysis of hydrogen market formation in the United States; the directions that companies are pursuing in hydrogen production transport and storage and end use at this early stage of value chain development will inform subsequent analysis in important ways.
Fundamentals, Materials, and Machine Learning of Polymer Electrolyte Membrane Fuel Cell Technology
Jun 2020
Publication
Polymer electrolyte membrane (PEM) fuel cells are electrochemical devices that directly convert the chemical energy stored in fuel into electrical energy with a practical conversion efficiency as high as 65%. In the past years significant progress has been made in PEM fuel cell commercialization. By 2019 there were over 19000 fuel cell electric vehicles (FCEV) and 340 hydrogen refueling stations (HRF) in the U.S. (~8000 and 44 respectively) Japan (~3600 and 112 respectively) South Korea (~5000 and 34 respectively) Europe (~2500 and 140 respectively) and China (~110 and 12 respectively). Japan South Korea and China plan to build approximately 3000 HRF stations by 2030. In 2019 Hyundai Nexo and Toyota Mirai accounted for approximately 63% and 32% of the total sales with a driving range of 380 and 312 miles and a mile per gallon (MPGe) of 65 and 67 respectively. Fundamentals of PEM fuel cells play a crucial role in the technological advancement to improve fuel cell performance/durability and reduce cost. Several key aspects for fuel cell design operational control and material development such as durability electrocatalyst materials water and thermal management dynamic operation and cold start are briefly explained in this work. Machine learning and artificial intelligence (AI) have received increasing attention in material/energy development. This review also discusses their applications and potential in the development of fundamental knowledge and correlations material selection and improvement cell design and optimization system control power management and monitoring of operation health for PEM fuel cells along with main physics in PEM fuel cells for physics-informed machine learning. The objective of this review is three fold: (1) to present the most recent status of PEM fuel cell applications in the portable stationary and transportation sectors; (2) to describe the important fundamentals for the further advancement of fuel cell technology in terms of design and control optimization cost reduction and durability improvement; and (3) to explain machine learning physics-informed deep learning and AI methods and describe their significant potentials in PEM fuel cell research and development (R&D).
Opportunities for Low-carbon Generation and Storage Technologies to Decarbonise the Future Power System
Feb 2023
Publication
Alternatives to cope with the challenges of high shares of renewable electricity in power systems have been addressed from different approaches such as energy storage and low-carbon technologies. However no model has previously considered integrating these technologies under stability requirements and different climate conditions. In this study we include this approach to analyse the role of new technologies to decarbonise the power system. The Spanish power system is modelled to provide insights for future applications in other regions. After including storage and low-carbon technologies (currently available and under development) batteries and hydrogen fuel cells have low penetration and the derived emission reduction is negligible in all scenarios. Compressed air storage would have a limited role in the short term but its performance improves in the long term. Flexible generation technologies based on hydrogen turbines and long-duration storage would allow the greatest decarbonisation providing stability and covering up to 11–14 % of demand in the short and long term. The hydrogen storage requirement is equivalent to 18 days of average demand (well below the theoretical storage potential in the region). When these solutions are considered decarbonising the electricity system (achieving Paris targets) is possible without a significant increase in system costs (< € 114/MWh).
Impact of Hydrogen/Natural Gas Blends on Partially Premixed Combustion Equipment: NOx Emission and Operational Performance
Feb 2022
Publication
Several North American utilities are planning to blend hydrogen into gas grids as a short‐ term way of addressing the scalable demand for hydrogen and as a long‐term decarbonization strat‐ egy for ‘difficult‐to‐electrify’ end uses. This study documents the impact of 0–30% hydrogen blends by volume on the performance emissions and safety of unadjusted equipment in a simulated use environment focusing on prevalent partially premixed combustion designs. Following a thorough literature review the authors describe three sets of results: operating standard and “ultra‐low NOx” burners from common heating equipment in “simulators” with hydrogen/methane blends up to 30% by volume in situ testing of the same heating equipment and field sampling of a wider range of equipment with 0–10% hydrogen/natural gas blends at a utility‐owned training facility. The equipment was successfully operated with up to 30% hydrogen‐blended fuels with limited visual changes to flames and key trends emerged: (a) a decrease in the input rate from 0 to 30% H2 up to 11% often in excess of the Wobbe Index‐based predictions; (b) NOx and CO emissions are flat or decline (air‐free or energy‐adjusted basis) with increasing hydrogen blending; and (c) a minor de‐ crease (1.2%) or increase (0.9%) in efficiency from 0 to 30% hydrogen blends for standard versus ultra‐low NOx‐type water heaters respectively.
Everything About Hydrogen Podcast: Building Europe's Hydrogen Mobility Network
Jan 2020
Publication
On this weeks episode the team are talking all things hydrogen with Jacob Krogsgaard the CEO of Everfuel a leading supplier of green hydrogen for mobility and industry in Europe. Since its establishment by Nel and a Consortium of parties and investors Everfuel has become a market leader in establishing green hydrogen solutions for mobility in Europe and has recently expanded into areas such as power-to-gas as well. The team catch up with Jacob on Everfuels business model the establishment of the H2Bus Consortium Jacob’s views on how the market for green hydrogen is evolving in Europe and where he sees the greatest early potential for scaling.…..All this and more on the show!
The podcast can be found on their website
The podcast can be found on their website
Direct Evidence for Solid-like Hydrogen in a Nanoporous Carbon Hydrogen Storage Material at Supercritical Temperatures
Jul 2015
Publication
Here we report direct physical evidence that confinement of molecular hydrogen (H2) in an optimized nanoporous carbon results in accumulation of hydrogen with characteristics commensurate with solid H2 at temperatures up to 67 K above the liquid vapor critical temperature of bulk H2. This extreme densification is attributed to confinement of H2 molecules in the optimally sized micropores and occurs at pressures as low as 0.02 MPa. The quantities of contained solid-like H2 increased with pressure and were directly evaluated using in situ inelastic neutron scattering and confirmed by analysis of gas sorption isotherms. The demonstration of the existence of solid-like H2 challenges the existing assumption that supercritical hydrogen confined in nanopores has an upper limit of liquid H2 density. Thus this insight offers opportunities for the development of more accurate models for the evaluation and design of nanoporous materials for high capacity adsorptive hydrogen storage.
Photocatalytic Hydrogen Evolution from Biomass Conversion
Feb 2021
Publication
Biomass has incredible potential as an alternative to fossil fuels for energy production that is sustainable for the future of humanity. Hydrogen evolution from photocatalytic biomass conversion not only produces valuable carbon-free energy in the form of molecular hydrogen but also provides an avenue of production for industrially relevant biomass products. This photocatalytic conversion can be realized with efficient sustainable reaction materials (biomass) and inexhaustible sunlight as the only energy inputs. Reported herein is a general strategy and mechanism for photocatalytic hydrogen evolution from biomass and biomass-derived substrates (including ethanol glycerol formic acid glucose and polysaccharides). Recent advancements in the synthesis and fundamental physical/mechanistic studies of novel photocatalysts for hydrogen evolution from biomass conversion are summarized. Also summarized are recent advancements in hydrogen evolution efciency regarding biomass and biomass-derived substrates. Special emphasis is given to methods that utilize unprocessed biomass as a substrate or synthetic photocatalyst material as the development of such will incur greater benefts towards a sustainable route for the evolution of hydrogen and production of chemical feedstocks.
Everything About Hydrogen Podcast: The Other Hydrogen Vehicle?
Oct 2019
Publication
For this episode we speak to Amanda Lyne the Managing Director of ULEMCo and the Chair of the UK Hydrogen and Fuel Cell Association (UKHFCA). Below are a few links to some of the content discussed on the show and some further background reading.
The podcast can be found on their website
The podcast can be found on their website
Can Industrial-Scale Solar Hydrogen Supplied from Commodity Technologies Be Cost Competitive by 2030?
Sep 2020
Publication
Expanding decarbonization efforts beyond the power sector are contingent on cost-effective production of energy carriers like H2 with near-zero life-cycle carbon emissions. Here we assess the levelized cost of continuous H2 supply (95% availability) at industrial-scale quantities (100 tonnes/day) in 2030 from integrating commodity technologies for solar photovoltaics electrolysis and energy storage. Our approach relies on modeling the least-cost plant design and operation that optimize component sizes while adhering to hourly solar availability production requirements and component inter-temporal operating constraints. We apply the model to study H2 production costs spanning the continental United States and through extensive sensitivity analysis explore system configurations that can achieve $2.5/kg levelized costs or less for a range of plausible 2030 technology projections at high-irradiance locations. Notably we identify potential sites and system configurations where PV-electrolytic H2 could substitute natural gas-derived H2 at avoided CO2 costs (%$120/ton) similar to the cost of deploying carbon capture and sequestration.
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