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.
Hydrogen Production and Carbon Sequestration by Steam Methane Reforming and Fracking with Carbon Dioxide
Feb 2020
Publication
An opportunity to sequester large amounts of carbon dioxide (CO2) is made possible because hydraulic fracturing is used to produce most of America's natural gas. CO2 could be extracted from natural gas and water using steam methane reforming pressurized to its supercritical phase and used instead of water to fracture additional hydrocarbon-bearing rock. The useful energy carrier that remains is hydrogen with carbon returned to the ground. Research on the use of supercritical CO2 is reviewed with proppant entrainment identified as the major area where technical advances may be needed. The large potential for greenhouse-gas reduction through sequestration of CO2 and avoidance of methane leakage from the natural gas system is quantified.
A Compilation of Operability and Emissions Performance of Residential Water Heaters Operated on Blends of Natural Gas and Hydrogen Including Consideration for Reporting Bases
Feb 2023
Publication
The impact of hydrogen added to natural gas on the performance of commercial domestic water heating devices has been discussed in several recent papers in the literature. Much of the work focuses on performance at specific hydrogen levels (by volume) up to 20–30% as a near term blend target. In the current work new data on several commercial devices have been obtained to help quantify upper limits based on flashback limits. In addition results from 39 individual devices are compiled to help generalize observations regarding performance. The emphasis of this work is on emissions performance and especially NOx emissions. It is important to consider the reporting bases of the emissions numbers to avoid any unitended bias. For water heaters the trends associated with both mass per fuel energy input and concentration-based representation are similar For carbon free fuels bases such as 12% CO2 should be avoided. In general the compiled data shows that NOx NO UHC and CO levels decrease with increasing hydrogen percentage. The % decrease in NOx and NO is greater for low NOx devices (meaning certified to NOx <10 ng/J using premixing with excess air) compared to conventional devices (“pancake burners” partial premixing). Further low NOx devices appear to be able to accept greater amounts of hydrogen above 70% hydrogen in some cases without modification while conventional water heaters appear limited to 40–50% hydrogen. Reporting emissions on a mass basis per unit fuel energy input is preferred to the typical dry concentration basis as the greater amount of water produced by hydrogen results in a perceived increase in NOx when hydrogen is used. While this effort summarizes emissions performance with added hydrogen additional work is needed on transient operation higher levels of hydrogen system durability/reliability and heating efficiency.
A Multi-period Sustainable Hydrogen Supply Chain Model Considering Pipeline Routing and Carbon Emissions: The Case Study of Oman
Nov 2022
Publication
This paper presents a mathematical model for a multi-period hydrogen supply chain design problem considering several design features not addressed in other studies. The model is formulated as a mixed-integer program allowing the production and storage facilities to be extended over time. Pipeline and tube trailer transport modes are considered for carrying hydrogen. The model also allows finding the optimal pipeline routes and the number of transport units. The objective is to obtain an efficient supply chain design within a given time frame in a way that the demand and carbon dioxide emissions constraints are satisfied and the total cost is minimized. A computer program is developed to ease the problem-solving process. The computer program extracts the geographical information from Google Maps and solves the problem using an optimization solver. Finally the applicability of the proposed model is demonstrated in a case study from Oman.
Hydrogen Production from Water Electrolysis: Role of Catalysts
Feb 2021
Publication
As a promising substitute for fossil fuels hydrogen has emerged as a clean and renewable energy. A key challenge is the efcient production of hydrogen to meet the commercial-scale demand of hydrogen. Water splitting electrolysis is a promising pathway to achieve the efcient hydrogen production in terms of energy conversion and storage in which catalysis or electrocatalysis plays a critical role. The development of active stable and low-cost catalysts or electrocatalysts is an essential prerequisite for achieving the desired electrocatalytic hydrogen production from water splitting for practical use which constitutes the central focus of this review. It will start with an introduction of the water splitting performance evaluation of various electrocatalysts in terms of activity stability and efciency. This will be followed by outlining current knowledge on the two half-cell reactions hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in terms of reaction mechanisms in alkaline and acidic media. Recent advances in the design and preparation of nanostructured noble-metal and non-noble metal-based electrocatalysts will be dis‑ cussed. New strategies and insights in exploring the synergistic structure morphology composition and active sites of the nanostructured electrocatalysts for increasing the electrocatalytic activity and stability in HER and OER will be highlighted. Finally future challenges and perspectives in the design of active and robust electrocatalysts for HER and OER towards efcient production of hydrogen from water splitting electrolysis will also be outlined.
Optimized Configuration of Diesel Engine-Fuel Cell-Battery Hybrid Power Systems in a Platform Supply Vessel to Reduce CO2 Emissions
Mar 2022
Publication
The main objective of this paper is to select the optimal configuration of a ship’s power system considering the use of fuel cells and batteries that would achieve the lowest CO2 emissions also taking into consideration the number of battery cycles. The ship analyzed in this work is a Platform Supply Vessel (PSV) used to support oil and gas offshore platforms transporting goods equipment and personnel. The proposed scheme considers the ship’s retrofitting. The ship’s original main generators are maintained and the fuel cell and batteries are installed as complementary sources. Moreover a sensitivity analysis is pursued on the ship’s demand curve. The simulations used to calculate the CO2 emissions for each of the new hybrid configurations were developed using HOMER software. The proposed solutions are auxiliary generators three types of batteries and a protonexchange membrane fuel cell (PEMFC) with different sizes of hydrogen tanks. The PEMFC and batteries were sized as containerized solutions and the sizing of the auxiliary engines was based on previous works. Each configuration consists of a combination of these solutions. The selection of the best configuration is one contribution of this paper. The new configurations are classified according to the reduction of CO2 emitted in comparison to the original system. For different demand levels the results indicate that the configuration classification may vary. Another valuable contribution of this work is the sizing of the battery and hydrogen storage systems. They were installed in 20 ft containers since the installation of batteries fuel cells and hydrogen tanks in containers is widely used for ship retrofit. As a result the most significant reduction of CO2 emissions is 10.69%. This is achieved when the configuration includes main generators auxiliary generators a 3119 kW lithium nickel manganese cobalt (LNMC) battery a 250 kW PEMFC and 581 kg of stored hydrogen.
Pore-scale Study of Microbial Hydrogen Consumption and Wettability Alteration During Underground Hydrogen Storage
Feb 2023
Publication
Hydrogen can be a renewable energy carrier and is suggested to store renewable energy and mitigate carbon dioxide emissions. Subsurface storage of hydrogen in salt caverns deep saline formations and depleted oil/gas reservoirs would help to overcome imbalances between supply and demand of renewable energy. Hydrogen however is one of the most important electron donors for many subsurface microbial processes including methanogenesis sulfate reduction and acetogenesis. These processes cause hydrogen loss and changes of reservoir properties during geological hydrogen storage operations. Here we report the results of a typical halophilic sulfate-reducing bacterium growing in a microfluidic pore network saturated with hydrogen gas at 35 bar and 37°C. Test duration is 9 days. We observed a significant loss of H2 from microbial consumption after 2 days following injection into a microfluidic device. The consumption rate decreased over time as the microbial activity declined in the pore network. The consumption rate is influenced profoundly by the surface area of H2 bubbles and microbial activity. Microbial growth in the silicon pore network was observed to change the surface wettability from a water-wet to a neutral-wet state. Due to the coupling effect of H2 consumption by microbes and wettability alteration the number of disconnected H2 bubbles in the pore network increased sharply over time. These results may have significant implications for hydrogen recovery and gas injectivity. First pore-scale experimental results reveal the impacts of subsurface microbial growth on H2 in storage which are useful to estimate rapidly the risk of microbial growth during subsurface H2 storage. Second microvisual experiments provide critical observations of bubble-liquid interfacial area and reaction rate that are essential to the modeling that is needed to make long-term predictions. Third results help us to improve the selection criteria for future storage sites.
Everything About Hydrogen Podcast: Hydrogen Review of 2022
Oct 2022
Publication
In order to wrap Season 3 of EAH appropriately we are honored to have our most popular EAH guest back with us Alicia Eastman President and Co-Founder of Intercontinental Energy is here to help us review the big hydrogen happenings of 2022 and preview some of the most important predictions and expectations for the sector coming for 2023.
The podcast can be found on their website.
The podcast can be found on their website.
Thermochemical Recuperation to Enable Efficient Ammonia-Diesel Dual-Fuel Combustion in a Compression Ignition Engine
Nov 2021
Publication
A thermochemical recuperation (TCR) reactor was developed and experimentally evaluated with the objective to improve dual-fuel diesel–ammonia compression ignition engines. The novel system simultaneously decomposed ammonia into a hydrogen-containing mixture to allow high diesel fuel replacement ratios and oxidized unburned ammonia emissions in the exhaust overcoming two key shortcomings of ammonia combustion in engines from the previous literature. In the experimental work a multi-cylinder compression ignition engine was operated in dual-fuel mode using intake-fumigated ammonia and hydrogen mixtures as the secondary fuel. A full-scale catalytic TCR reactor was constructed and generated the fuel used in the engine experiments. The results show that up to 55% of the total fuel energy was provided by ammonia on a lower heating value basis. Overall engine brake thermal efficiency increased for modes with a high exhaust temperature where ammonia decomposition conversion in the TCR reactor was high but decreased for all other modes due to poor combustion efficiency. Hydrocarbon and soot emissions were shown to increase with the replacement ratio for all modes due to lower combustion temperatures and in-cylinder oxidation processes in the late part of heat release. Engine-out oxides of nitrogen (NOx) emissions decreased with increasing diesel replacement levels for all engine modes. A higher concentration of unburned ammonia was measured in the exhaust with increasing replacement ratios. This unburned ammonia predominantly oxidized to NOx species over the oxidation catalyst used within the TCR reactor. Ammonia substitution thus increased post-TCR reactor ammonia and NOx emissions in this work. The results show however that engine-out NH3 -to-NOx ratios were suitable for passive selective catalytic reduction thus demonstrating that both ammonia and NOx from the engine could be readily converted to N2 if the appropriate catalyst were used in the TCR reactor.
The Potential of Zero-carbon Bunker Fuels in Developing Countries
Apr 2015
Publication
To meet the climate targets set forth in the International Maritime Organization’s Initial GHG Strategy the maritime transport sector needs to abandon the use of fossil-based bunker fuels and turn toward zero-carbon alternatives which emit zero or at most very low greenhouse gas (GHG) emissions throughout their lifecycles. This report “The Potential of Zero-Carbon Bunker Fuels in Developing Countries” examines a range of zero-carbon bunker fuel options that are considered to be major contributors to shipping’s decarbonized future: biofuels hydrogen and ammonia and synthetic carbon-based fuels. The comparison shows that green ammonia and green hydrogen strike the most advantageous balance of favorable features due to their lifecycle GHG emissions broader environmental factors scalability economics and technical and safety implications. Furthermore the report finds that many countries including developing countries are very well positioned to become future suppliers of zero-carbon bunker fuels—namely ammonia and hydrogen. By embracing their potential these countries would be able to tap into an estimated $1+ trillion future fuel market while modernizing their own domestic energy and industrial infrastructure. However strategic policy interventions are needed to unlock these potentials.
Everything About Hydrogen Podcast: Hydrogen in the E-Mobility Sector
Oct 2021
Publication
Quantron AG was created in 2019 as a high-tech spin-off of the well-known Haller GmbH & Co. KG with the vision of paving the way for e-mobility in inner-city and regional passenger and cargo transportation. Quantron AG combines innovative ability and expertise in e-vans e-trucks and e-buses with the long-standing knowledge and experience of Haller GmbH & Co. KG in the commercial vehicle sector. The company's approach to e-Mobility is defined by its commitment to leveraging the most effective zero-emission vehicle technology for the use case which means Quantron is building both hydrogen fuel cell electric vehicles (FCEVs) and battery electric vehicles (BEVs) for its clients.
The podcast can be found on the website
The podcast can be found on the website
Everything About Hydrogen Podcast: Supplying the Building Blocks of an Energy Revolution
Apr 2021
Publication
On this episode of Everything About Hydrogen the team is joined by Sam French Business Development Director at JM who spent some time speaking with us about the transition from grey hydrogen to low-carbon generation technologies and what steps the UK - and countries all over the world - to use hydrogen as part of the pathway to a sustainable energy future.
The podcast can be found on their website
The podcast can be found on their website
Thermodynamics, Energy Dissipation, and Figures of Merit of Energy Storage Systems—A Critical Review
Sep 2021
Publication
The path to the mitigation of global climate change and global carbon dioxide emissions avoidance leads to the large-scale substitution of fossil fuels for the generation of electricity with renewable energy sources. The transition to renewables necessitates the development of large-scale energy storage systems that will satisfy the hourly demand of the consumers. This paper offers an overview of the energy storage systems that are available to assist with the transition to renewable energy. The systems are classified as mechanical (PHS CAES flywheels springs) electromagnetic (capacitors electric and magnetic fields) electrochemical (batteries including flow batteries) hydrogen and thermal energy storage systems. Emphasis is placed on the magnitude of energy storage each system is able to achieve the thermodynamic characteristics the particular applications the systems are suitable for the pertinent figures of merit and the energy dissipation during the charging and discharging of the systems.
The Socio-technical Dynamics of Net-zero Industrial Megaprojects: Outside-in and Inside-out Analyses of the Humber Industrial Cluster
Feb 2023
Publication
Although energy-intensive industries are often seen as ‘hard-to-decarbonise’ net-zero megaprojects for industrial clusters promise to improve the technical and economic feasibility of hydrogen fuel switching and carbon capture and storage (CCS). Mobilising insights from the megaproject literature this paper analyses the dynamics of an ambitious first-of-kind net-zero megaproject in the Humber industrial cluster in the United Kingdom which includes CCS and hydrogen infrastructure systems industrial fuel switching CO2 capture green and blue hydrogen production and hydrogen storage. To analyse the dynamics of this emerging megaproject the article uses a socio-technical system lens to focus on developments in technology actors and institutions. Synthesising multiple megaproject literature insights the paper develops a comprehensive framework that addresses both aggregate (‘outside-in’) developments and the endogenous (‘inside-out’) experiences and activities regarding three specific challenges: technical system integration actor coordination and institutional alignment. Drawing on an original dataset involving expert interviews (N = 46) site visits (N = 7) and document analysis the ‘outside-in’ analysis finds that the Humber megaproject has progressed rapidly from outline visions to specific technical designs enacted by new coalitions and driven by strengthening policy targets and financial support schemes. The complementary ‘inside-out’ analysis however also finds 12 alignment challenges that can delay or derail materialisation of the plans. While policies are essential aggregate drivers institutional misalignments presently also prevent project-actors from finalising design and investment decisions. Our analysis also finds important tensions between the project's high-pace delivery focus (to meet government targets) and allowing sufficient time for pilot projects learning-by-doing and design iterations.
Underground Storage of Hydrogen and Hydrogen/methane Mixtures in Porous Reservoirs: Influence of Reservoir Factors and Engineering Choices on Deliverability and Storage Operations
Jul 2023
Publication
Seasonal storage of natural gas (NG) which primarily consists of methane (CH4) has been practiced for more than a hundred years at underground gas storage (UGS) facilities that use depleted hydrocarbon reservoirs saline aquifers and salt caverns. To support a transition to a hydrogen (H2) economy similar facilities are envisioned for long-duration underground H2 storage (UHS) of either H2 or H2/CH4 mixtures. Experience with UGS can be used to guide the deployment of UHS so we identify and quantify factors (formation/fluid properties and engineering choices) that influence reservoir behavior (e.g. viscous fingering and gravity override) the required number of injection/withdrawal wells and required storage volume contrasting the differences between the storage of CH4 H2 and H2/CH4 mixtures. The most important engineering choices are found to be the H2 fraction in H2/CH4 mixtures storage depth and injection rate. Storage at greater depths (higher pressure) but with relatively lower temperature is more favorable because it maximizes volumetric energy-storage density while minimizing viscous fingering and gravity override due to buoyancy. To store an equivalent amount of energy storing H2/CH4 mixtures in UHS facilities will require more wells and greater reservoir volume than corresponding UGS facilities. We use our findings to make recommendations about further research needed to guide deployment of UHS in porous reservoirs.
Increasing Energy Efficiency of Hydrogen Refueling Stations via Optimal Thermodynamic Paths
Sep 2023
Publication
This work addresses the energy efficiency of hydrogen refueling stations (HRS) using a first principles model and optimal control methods to find minimal entropy production operating paths. The HRS model shows good agreement with experimental data achieving maximum state of charge and temperature discrepancies of 1 and 7% respectively. Model solution and optimization is achieved at a relatively low computational time (40 s) when compared to models of the same degree of accuracy. The entropy production mapping indicates the flow control valve as the main source of irreversibility accounting for 85% of the total entropy production in the process. The minimal entropy production refueling path achieves energy savings from 20 to 27% with respect to the SAE J2601 protocol depending on the ambient temperature. Finally the proposed method under nearreversible refueling conditions shows a theoretical reduction of 43% in the energy demand with respect to the SAE J2601 protocol.
Economic Performance Evaluation of Flexible Centralised and Decentralised Blue Hydrogen Production Systems Design Under Uncertainty
Sep 2023
Publication
Blue hydrogen is viewed as an important energy vector in a decarbonised global economy but its large-scale and capital-intensive production displays economic performance vulnerabities in the face of increased market and regulatory uncertainty. This study analyses flexible (modular) blue hydrogen production plant designs and evaluates their effectiveness to enhance economic performance under uncertainty. The novelty of this work lies in the development of a comprehensive techno-economic evaluation framework that considers flexible centralised and decentralised blue hydrogen plant design alternatives in the presence of irreducible uncertainty whilst explicitly considering the time value of money economies of scale and learning effects. A case study of centralised and decentralised blue hydrogen production for the transport sector in the San Francisco area is developed to highlight the underlying value of flexibility. The proposed methodological framework considers various blue hydrogen plant designs (fixed phased and flexible) and compares them using relevant economic indicators (net present value (NPV) capex value-at-risk/gain etc.) through a detailed Monte Carlo simulation framework. Results indicate that flexible centralised hydrogen production yields greater economic value than alternative designs despite the associated cost-premium of modularity. It is also shown that the value of flexibility increases under greater uncertainty higher learning rates and weaker economies of scale. Moreover sensitivity analysis reveals that flexible design remains the preferred investment option over a wide range of market and regulatory conditions except for high initial hydrogen demand. Finally this study demonstrates that major regulatory and market uncertainties surrounding blue hydrogen production can be effectively managed through the application of flexible engineering system design that protects the investment from major downside risks whilst allowing access to favourable upside opportunities.
Hydrogen and the Global Energy Transition—Path to Sustainability and Adoption across All Economic Sectors
Feb 2024
Publication
This perspective article delves into the critical role of hydrogen as a sustainable energy carrier in the context of the ongoing global energy transition. Hydrogen with its potential to decarbonize various sectors has emerged as a key player in achieving decarbonization and energy sustainability goals. This article provides an overview of the current state of hydrogen technology its production methods and its applications across diverse industries. By exploring the challenges and opportunities associated with hydrogen integration we aim to shed light on the pathways toward achieving a sustainable hydrogen economy. Additionally the article underscores the need for collaborative efforts among policymakers industries and researchers to overcome existing hurdles and unlock the full potential of hydrogen in the transition to a low-carbon future. Through a balanced analysis of the present landscape and future prospects this perspective article aims to contribute valuable insights to the discourse surrounding hydrogen’s role in the global energy transition.
The Transition to a Renewable Energy Electric Grid in the Caribbean Island Nation of Antigua and Barbuda
Aug 2023
Publication
The present study describes the development and application of a model of the national electricity system for the Caribbean dual-island nation of Antigua and Barbuda to investigate the cost optimal mix of solar photovoltaics (PVs) wind and in the most novel contribution concentrating solar power (CSP). These technologies together with battery and hydrogen energy storage can enable the aim of achieving 100% renewable electricity and zero carbon emissions. The motivation for this study was that while most nations in the Caribbean rely largely on diesel fuel or heavy fuel oil for grid electricity generation many countries have renewable resources beyond wind and solar energy. Antigua and Barbuda generates 93% of its electricity from diesel-fueled generators and has set the target of becoming a net-zero nation by 2040 as well as having 86% renewable energy generation in the electricity sector by 2030 but the nation has no hydroelectric or geothermal resources. Thus this study aims to demonstrate that CSP is a renewable energy technology that can help assist Antigua and Barbuda in its transition to a renewable energy electric grid while also decreasing electricity generation costs. The modeled optimal mix of renewable energy technologies presented here was found for Antigua and Barbuda by assessing the levelized cost of electricity (LCOE) for systems comprising various combinations of energy technologies and storage. Other factors were also considered such as land use and job creation. It was found that 100% renewable electricity systems are viable and significantly less costly than current power systems and that there is no single defined pathway towards a 100% renewable energy grid but several options are available.
Near-term Infrastructure Rollout and Investment Strategies for Net-zero Hydrogen Supply Chains
Feb 2024
Publication
Low-carbon hydrogen plays a key role in European industrial decarbonization strategies. This work investigates the cost-optimal planning of European low-carbon hydrogen supply chains in the near term (2025–2035) comparing several hydrogen production technologies and considering multiple spatial scales. We focus on mature hydrogen production technologies: steam methane reforming of natural gas biomethane reforming biomass gasification and water electrolysis. The analysis includes carbon capture and storage for natural gas and biomass-derived hydrogen. We formulate and solve a linear optimization model that determines the costoptimal type size and location of hydrogen production and transport technologies in compliance with selected carbon emission targets including the EU fit for 55 target and an ambitious net-zero emissions target for 2035. Existing steam methane reforming capacities are considered and optimal carbon and biomass networks are designed. Findings identify biomass-based hydrogen production as the most cost-efficient hydrogen technology. Carbon capture and storage is installed to achieve net-zero carbon emissions while electrolysis remains costdisadvantageous and is deployed on a limited scale across all considered sensitivity scenarios. Our analysis highlights the importance of spatial resolution revealing that national perspectives underestimate costs by neglecting domestic transport needs and regional resource constraints emphasizing the necessity for highly decarbonized infrastructure designs aligned with renewable resource availabilities.
Thermocatalytic Hydrogen Production Through Decomposition of Methane-A Review
Oct 2021
Publication
Consumption of fossil fuels especially in transport and energy-dependent sectors has led to large greenhouse gas production. Hydrogen is an exciting energy source that can serve our energy purposes and decrease toxic waste production. Decomposition of methane yields hydrogen devoid of COx components thereby aiding as an eco-friendly approach towards large-scale hydrogen production. This review article is focused on hydrogen production through thermocatalytic methane decomposition (TMD) for hydrogen production. The thermodynamics of this approach has been highlighted. Various methods of hydrogen production from fossil fuels and renewable resources were discussed. Methods including steam methane reforming partial oxidation of methane auto thermal reforming direct biomass gasification thermal water splitting methane pyrolysis aqueous reforming and coal gasification have been reported in this article. A detailed overview of the different types of catalysts available the reasons behind their deactivation and their possible regeneration methods were discussed. Finally we presented the challenges and future perspectives for hydrogen production via TMD. This review concluded that among all catalysts nickel ruthenium and platinum-based catalysts show the highest activity and catalytic efficiency and gave carbon-free hydrogen products during the TMD process. However their rapid deactivation at high temperatures still needs the attention of the scientific community.
Solar Hydrogen for High Capacity, Dispatchable, Long-distance Energy transmission – A Case Study for Injection in the Greenstream Natural Gas Pipeline
Nov 2022
Publication
This paper presents the results of techno-economic modelling for hydrogen production from a photovoltaic battery electrolyser system (PBES) for injection into a natural gas transmission line. Mellitah in Libya connected to Gela in Italy by the Greenstream subsea gas transmission line is selected as the location for a case study. The PBES includes photovoltaic (PV) arrays battery electrolyser hydrogen compressor and large-scale hydrogen storage to maintain constant hydrogen volume fraction in the pipeline. Two PBES configurations with different large-scale storage methods are evaluated: PBESC with compressed hydrogen stored in buried pipes and PBESL with liquefied hydrogen stored in spherical tanks. Simulated hourly PV electricity generation is used to calculate the specific hourly capacity factor of a hypothetical PV array in Mellitah. This capacity factor is then used with different PV sizes for sizing the PBES. The levelised cost of delivered hydrogen (LCOHD) is used as the key techno-economic parameter to optimise the size of the PBES by equipment sizing. The costs of all equipment except the PV array and batteries are made to be a function of electrolyser size. The equipment sizes are deemed optimal if PBES meets hydrogen demand at the minimum LCOHD. The techno-economic performance of the PBES is evaluated for four scenarios of fixed and constant hydrogen volume fraction targets in the pipeline: 5% 10% 15% and 20%. The PBES can produce up to 106 kilotonnes of hydrogen per year to meet the 20% target at an LCOHD of 3.69 €/kg for compressed hydrogen storage (PBESC) and 2.81 €/kg for liquid hydrogen storage (PBESL). Storing liquid hydrogen at large-scale is significantly cheaper than gaseous hydrogen even with the inclusion of a significantly larger PV array that is required to supply additional electrcitiy for liquefaction.
A Comprehensive Resilience Assessment Framework for Hydrogen Energy Infrastructure Development
Jun 2023
Publication
In recent years sustainable development has become a challenge for many societies due to natural or other disruptive events which have disrupted economic environmental and energy infrastructure growth. Developing hydrogen energy infrastructure is crucial for sustainable development because of its numerous benefits over conventional energy sources. However the complexity of hydrogen energy infrastructure including production utilization and storage stages requires accounting for potential vulnerabilities. Therefore resilience needs to be considered along with sustainable development. This paper proposes a decision-making framework to evaluate the resilience of hydrogen energy infrastructure by integrating resilience indicators and sustainability contributing factors. A holistic taxonomy of resilience performance is first developed followed by a qualitative resilience assessment framework using a novel Intuitionistic fuzzy Weighted Influence Nonlinear Gauge System (IFWINGS). The results highlighted that Regulation and legislation Government preparation and Crisis response budget are the most critical resilience indicators in the understudy hydrogen energy infrastructure. A comparative case study demonstrates the practicality capability and effectiveness of the proposed approach. The results suggest that the proposed model can be used for resilience assessment in other areas.
Evaluation of Hydrogen Blend Stability in Low-Pressure Gas Distribution
Apr 2023
Publication
Natural gas distribution companies are developing ambitious plans to decarbonize the services that they provide in an affordable manner and are accelerating plans for the strategic integration of renewable natural gas and the blending of green hydrogen produced by electrolysis powered with renewable electricity being developed from large new commitments by states such as New York and Massachusetts. The demonstration and deployment of hydrogen blending have been proposed broadly at 20% of hydrogen by volume. The safe distribution of hydrogen blends in existing networks requires hydrogen blends to exhibit similar behavior as current supplies which are also mixtures of several hydrocarbons and inert gases. There has been limited research on the properties of blended hydrogen in low-pressure natural gas distribution systems. Current natural gas mixtures are known to be sufficiently stable in terms of a lack of chemical reaction between constituents and to remain homogeneous through compression and distribution. Homogeneous mixtures are required both to ensure safe operation of customer-owned equipment and for safety operations such as leak detection. To evaluate the stability of mixtures of hydrogen and natural gas National Grid experimentally tested a simulated distribution natural gas pipeline with blends containing hydrogen at up to 50% by volume. The pipeline was outfitted with ports to extract samples from the top and bottom of the pipe at intervals of 20 feet. Samples were analyzed for composition and the effectiveness of odorant was also evaluated. The new results conclusively demonstrate that hydrogen gas mixtures do not significantly separate or react under typical distribution pipeline conditions and gas velocity profiles. In addition the odorant retained its integrity in the blended gas during the experiments and demonstrated that it remains an effective method of leak detection.
Fission Battery Markets and Economic Requirements
Oct 2022
Publication
Fission Batteries (FBs) are nuclear reactors for customers with heat demands less than 250 MWt—replacing oil and natural gas in a low-carbon economy. Individual FBs would have outputs between 5 and 30 MWt. The small FB size has two major benefits: (1) the possibility of mass production and (2) ease of transport and leasing with return of used FBs to factory for refurbishing and reuse. Comparatively these two features are lacking in larger conventional reactors. Larger reactors are not transportable and thus can’t obtain the manufacturing economics possible with mass production or the operational advantages of returning the FB to the factory after use. Leasing places the regulatory maintenance and fuel-cycle burden on the leasing company that is minimized by large-fleet operations of identical units. The markets and economic requirements for FBs were examined. The primary existing markets are industrial biofuels off-grid electricity and container ships. Two major future markets were identified—advanced biofuels and hydrogen. In a low-carbon world the competitive price range for heat is $20–50/MWh ($6–15/million BTU) and $70–115/MWh for non-grid electricity. The primary competition in these sectors is likely to be biofuels and hydrogen produced using alternative energy sources—grid electricity is non-competitive. Larger users of energy have alternative low-carbon energy choices including modular nuclear reactors and fossil fuels with carbon capture and sequestration (CCS).
Review on Ammonia as a Potential Fuel: From Synthesis to Economics
Feb 2021
Publication
Ammonia a molecule that is gaining more interest as a fueling vector has been considered as a candidate to power transport produce energy and support heating applications for decades. However the particular characteristics of the molecule always made it a chemical with low if any benefit once compared to conventional fossil fuels. Still the current need to decarbonize our economy makes the search of new methods crucial to use chemicals such as ammonia that can be produced and employed without incurring in the emission of carbon oxides. Therefore current efforts in this field are leading scientists industries and governments to seriously invest efforts in the development of holistic solutions capable of making ammonia a viable fuel for the transition toward a clean future. On that basis this review has approached the subject gathering inputs from scientists actively working on the topic. The review starts from the importance of ammonia as an energy vector moving through all of the steps in the production distribution utilization safety legal considerations and economic aspects of the use of such a molecule to support the future energy mix. Fundamentals of combustion and practical cases for the recovery of energy of ammonia are also addressed thus providing a complete view of what potentially could become a vector of crucial importance to the mitigation of carbon emissions. Different from other works this review seeks to provide a holistic perspective of ammonia as a chemical that presents benefits and constraints for storing energy from sustainable sources. State-of-the-art knowledge provided by academics actively engaged with the topic at various fronts also enables a clear vision of the progress in each of the branches of ammonia as an energy carrier. Further the fundamental boundaries of the use of the molecule are expanded to real technical issues for all potential technologies capable of using it for energy purposes legal barriers that will be faced to achieve its deployment safety and environmental considerations that impose a critical aspect for acceptance and wellbeing and economic implications for the use of ammonia across all aspects approached for the production and implementation of this chemical as a fueling source. Herein this work sets the principles research practicalities and future views of a transition toward a future where ammonia will be a major energy player.
Minimizing the Cost of Hydrogen Production through Dynamic Polymer Electrolyte Membrane Electrolyzer Operation
Jun 2022
Publication
Growing imbalances between electricity demand and supply from variable renewable energy sources (VREs) create increasingly large swings in electricity prices. Polymer electrolyte membrane (PEM) electrolyzers can help to buffer against these imbalances and minimize the levelized cost of hydrogen (LCOH) by ramping up production of hydrogen through high-current-density operation when low-cost electricity is abundant and ramping down current density to operate efficiently when electricity prices are high. We introduce a technoeconomic model that optimizes current density profiles for dynamically operated electrolyzers while accounting for the potential of increased degradation rates to minimize LCOH for any given time-of-use (TOU) electricity pricing. This model is used to predict LCOH from different methods of operating a PEM electrolyzer for historical and projected electricity prices in California and Texas which were chosen due to their high penetration of VREs. Results reveal that dynamic operation could enable reductions in LCOH ranging from 2% to 63% for historical 2020 pricing and 1% to 53% for projected 2030 pricing. Moreover high-current-density operation above 2.5 A cm2 is increasingly justified at electricity prices below $0.03 kWh1 . These findings suggest an actionable means of lowering LCOH and guide PEM electrolyzer development toward devices that can operate efficiently at a range of current densities.
The Viability of Implementing Hydrogen in the Commonwealth of Massachusetts
Sep 2022
Publication
In recent years there has been an increased interest in hydrogen energy due to a desire to reduce greenhouse gas emissions by utilizing hydrogen for numerous applications. Some countries (e.g. Japan Iceland and parts of Europe) have made great strides in the advancement of hydrogen generation and utilization. However in the United States there remains significant reservation and public uncertainty on the use and integration of hydrogen into the energy ecosystem. Massachusetts similar to many other states and small countries faces technical infrastructure policy safety and acceptance challenges with regards to hydrogen production and utilization. A hydrogen economy has the potential to provide economic benefits a reduction in greenhouse gas emissions and sector coupling to provide a resilient energy grid. In this paper the issues associated with integrating hydrogen into Massachusetts and other similar states or regions are studied to determine which hydrogen applications have the most potential understand the technical and integration challenges and identify how a hydrogen energy economy may be beneficial. Additionally hydrogen’s safety concerns and possible contribution to greenhouse gas emissions are also reviewed. Ultimately a set of eight recommendations is made to guide the Commonwealth’s consideration of hydrogen as a key component of its policies on carbon emissions and energy.
Modeling the Global Annual Carbon Footprint for the Transportation Sector and a Path to Sustainability
Jun 2023
Publication
The transportation industry’s transition to carbon neutrality is essential for addressing sustainability concerns. This study details a model for calculating the carbon footprint of the transportation sector as it progresses towards carbon neutrality. The model aims to support policymakers in estimating the potential impact of various decisions regarding transportation technology and infrastructure. It accounts for energy demand technological advancements and infrastructure upgrades as they relate to each transportation market: passenger vehicles commercial vehicles aircraft watercraft and trains. A technology roadmap underlies this model outlining anticipated advancements in batteries hydrogen storage biofuels renewable grid electricity and carbon capture and sequestration. By estimating the demand and the technologies that comprise each transportation market the model estimates carbon emissions. Results indicate that based on the technology roadmap carbon neutrality can be achieved by 2070 for the transportation sector. Furthermore the model found that carbon neutrality can still be achieved with slippage in the technology development schedule; however delays in infrastructure updates will delay carbon neutrality while resulting in a substantial increase in the cumulative carbon footprint of the transportation sector.
Policy Design for Diffusing Hydrogen Economy and Its Impact on the Japanese Economy for Carbon Neutrality by 2050: Analysis Using the E3ME-FTT Model
Nov 2023
Publication
To achieve carbon neutrality in Japan by 2050 renewable energy needs to be used as the main energy source. Based on the constraints of various renewable energies the importance of hydrogen cannot be ignored. This study aimed to investigate the diffusion of hydrogen demand technologies in various sectors and used projections and assumptions to investigate the hydrogen supply side. By performing simulations with the E3ME-FTT model and comparing various policy scenarios with the reference scenario the economic and environmental impacts of the policy scenarios for hydrogen diffusion were analyzed. Moreover the impact of realizing carbon neutrality by 2050 on the Japanese economy was evaluated. Our results revealed that large-scale decarbonization via hydrogen diffusion is possible (90% decrease of CO2 emissions in 2050 compared to the reference) without the loss of economic activity. Additionally investments in new hydrogen-based and other low-carbon technologies in the power sector freight road transport and iron and steel industry can improve the gross domestic product (1.6% increase in 2050 compared to the reference) as they invoke economic activity and require additional employment (0.6% increase in 2050 compared to the reference). Most of the employment gains are related to decarbonizing the power sector and scaling up the hydrogen supply sector while a lot of job losses can be expected in the mining and fossil fuel industries.
Feasibility of Hydrogen Fuel Cell Technology for Railway Intercity Services: A Case Study for the Piedmont in North Carolina
Jul 2021
Publication
Diesel fuel combustion results in exhaust containing air pollutants and greenhouse gas emissions. Many railway vehicles use diesel fuel as their energy source. Exhaust emissions as well as concerns about economical alternative power supply have driven efforts to move to hydrogen motive power. Hydrogen fuel cell technology applied to railways offers the opportunity to eliminate harmful exhaust emissions and the potential for a low- or zero-emission energy supply chain. Currently only multiple-unit trains with hydrail technology operate commercially. Development of an Integrated Hybrid Train Simulator for intercity railway is presented. The proposed tool incorporates the effect of powertrain components during the wheel-to-tank process. Compared to its predecessors the proposed reconfigurable tool provides high fidelity with medium requirements and minimum computation time. Single train simulation and the federal government’s Greenhouse gases Regulated Emissions and Energy use in Transportation (GREET) model are used in combination to evaluate the feasibility of various train and powertrain configurations. The Piedmont intercity service operating in North Carolina is used as a case study. The study includes six train configurations and powertrain options as well as nine hydrogen supply options in addition to the diesel supply. The results show that a hydrail option is not only feasible but a low- or zero-carbon hydrogen supply chain could be possible.
Renewable Hydrogen and Synthetic Fuels Versus Fossil Fuels for Trucking, Shipping and Aviation: A Holistic Cost Model
Aug 2023
Publication
Potential carbon neutrality of the global trucking shipping and aviation sectors by 2050 could be achieved by substituting fossil fuels with renewable hydrogen and synthetic fuels. To investigate the economic impact of fuel substitution over time a holistic cost model is developed and applied to three case studies in Norway an early adopter of carbon-neutral freight transport. The model covers the value chains from local electricity and fuel production (hydrogen ammonia Fischer–Tropsch e-fuel) to fuel consumption for long-haul trucking short-sea shipping and mid-haul aviation. The estimates are internally consistent and allow cross-mode and cross-fuel comparisons that set this work apart from previous studies more narrowly focused on a given transport mode or fuel. The model contains 150 techno-economic parameters to identify which components along the value chains drive levelized costs. This paper finds a cost reduction potential for renewable fuels of 41% to 68% until 2050 but carbon-neutral transport will suffer asymmetric cost disadvantages. Fuel substitution is most expensive in short-sea shipping followed by mid-haul aviation and long-haul trucking. Cost developments of electricity direct air capture of carbon vehicle expenses and fuel-related payload losses are significant drivers.
Renewable Energy Transport via Hydrogen Pipelines and HVDC Transmission Lines
May 2021
Publication
The majority penetration of Variable Renewable Energy (VRE) will challenge the stability of electrical transmission grids due to unpredictable peaks and troughs of VRE generation. With renewable generation located further from high demand urban cores there will be a need to develop new transmission pathways to deliver the power. This paper compares the transport and storage of VRE through a hydrogen pipeline to the transport of VRE through a High Voltage Direct Current (HVDC) transmission line. The analysis found a hydrogen pipeline can offer a cost-competitive method for VRE transmission compared to a HVDC transmission line on a life-cycle cost basis normalized by energy flows for distances at 1000 miles with 2030 technology. This finding has implications for policy makers project developers and system operators for the future development of transmission infrastructure projects given the additionality which hydrogen pipelines can provide in terms of energy storage.
Opportunities for Flexible Electricity Loads such as Hydrogen Production from Curtailed Generation
Jun 2021
Publication
Variable low-cost low-carbon electricity that would otherwise be curtailed may provide a substantial economic opportunity for entities that can flexibly adapt their electricity consumption. We used historical hourly weather data over the contiguous U.S. to model the characteristics of least-cost electricity systems dominated by variable renewable generation that powered firm and flexible electricity demands (loads). Scenarios evaluated included variable wind and solar power battery storage and dispatchable natural gas with carbon capture and storage with electrolytic hydrogen representing a prototypical flexible load. When flexible loads were small excess generation capacity was available during most hours allowing flexible loads to operate at high capacity factors. Expanding the flexible loads allowed the least-cost systems to more fully utilize the generation capacity built to supply firm loads and thus reduced the average cost of delivered electricity. The macro-scale energy model indicated that variable renewable electricity systems optimized to supply firm loads at current costs could supply 25% or more additional flexible load with minimal capacity expansion while resulting in reduced average electricity costs (10% or less capacity expansion and 10% to 20% reduction in costs in our modeled scenarios). These results indicate that adding flexible loads to electricity systems will likely allow more full utilization of generation assets across a wide range of system architectures thus providing new energy services with infrastructure that is already needed to supply firm electricity loads.
Model to Inform the Expansion of Hydrogen Distribution Infrastructure
Jul 2023
Publication
A growing hydrogen economy requires new hydrogen distribution infrastructure to link geographically distributed hubs of supply and demand. The Hydrogen Optimization with Deployment of Infrastructure (HOwDI) Model helps meet this requirement. The model is a spatially resolved optimization framework that determines location-specific hydrogen production and distribution infrastructure to cost-optimally meet a specified location-based demand. While these results are useful in understanding hydrogen infrastructure development there is uncertainty in some costs that the model uses for inputs. Thus the project team took the modeling effort a step further and developed a Monte Carlo methodology to help manage uncertainties. Seven scenarios were run using existing infrastructure and new demand in Texas exploring different policy and tax approaches. The inclusion of tax credits increased the percentage of runs that could deliver hydrogen at <$4/kg from 31% to 77% and decreased the average dispensed cost from $4.35/kg to $3.55/kg. However even with tax credits there are still some runs where unabated SMR is deployed to meet new demand as the low-carbon production options are not competitive. Every scenario except for the zero-carbon scenario (without tax credits) resulted in at least 20% of the runs meeting the $4/kg dispensed fuel cost target. This indicates that multiple pathways exist to deliver $4/kg hydrogen.
Economic Assessment of Clean Hydrogen Production from Fossil Fuels in the Intermountain-west Region, USA
Jan 2024
Publication
The transition from fossil fuels to carbon-neutral energy sources is necessary to reduce greenhouse gas (GHG) emissions and combat climate change. Hydrogen (H2) provides a promising path to harness fossil fuels to reduce emissions in sectors such as transportation. However regional economic analyses of various H2 production techniques are still lacking. We selected a well-known fossil fuel-exporting region the USA’s Intermountain-West (I-WEST) to analyze the carbon intensity of H2 production and demonstrate regional tradeoffs. Currently 78 % of global H2 production comes from natural gas and coal. Therefore we considered steam methane reforming (SMR) surface coal gasification (SCG) and underground coal gasification (UCG) as H2 production methods in this work. We developed the cost estimation frameworks of SMR SCG and UCG with and without carbon capture utilization and sequestration (CCUS). In addition we identified optimal sites for H2 hubs by considering the proximity to energy sources energy markets storage sites and CO2 sequestration sites. We included new production tax credits (PTCs) in the cost estimation to quantify the economic benefit of CCUS. Our results suggest that the UCG has the lowest levelized cost of H2 production due to the elimination of coal production cost. H2 production using the SMR process with 99 % carbon capture is profitable when the PTCs are considered. We also analyzed carbon utilization opportunities where CO2 conversion to formic acid is a promising profitable option. This work quantifies the potential of H2 production from fossil fuels in the I-WEST region a key parameter for designing energy transition pathways.
An Overview of Challenges for the Future of Hydrogen
Oct 2023
Publication
Hydrogen’s wide availability and versatile production methods establish it as a primary green energy source driving substantial interest among the public industry and governments due to its future fuel potential. Notable investment is directed toward hydrogen research and material innovation for transmission storage fuel cells and sensors. Ensuring safe and dependable hydrogen facilities is paramount given the challenges in accident control. Addressing material compatibility issues within hydrogen systems remains a critical focus. Challenges roadmaps and scenarios steer long-term planning and technology outlooks. Strategic visions align actions and policies encompassing societal and ecological dimensions. The confluence of hydrogen’s promise with material progress holds the prospect of reshaping our energy landscape sustainably. Forming collective future perspectives to foresee this emerging technology’s potential benefits is valuable. Our review article comprehensively explores the forthcoming challenges in hydrogen technology. We extensively examine the challenges and opportunities associated with hydrogen production incorporating CO2 capture technology. Furthermore the interaction of materials and composites with hydrogen particularly in the context of hydrogen transmission pipeline and infrastructure are discussed to understand the interplay between materials and hydrogen dynamics. Additionally the exploration extends to the embrittlement phenomena during storage and transmission coupled with a comprehensive examination of the advancements and hurdles intrinsic to hydrogen fuel cells. Finally our exploration encompasses addressing hydrogen safety from an industrial perspective. By illuminating these dimensions our article provides a panoramic view of the evolving hydrogen landscape.
The Prospects of Hydrogen in Achieving Net Zero Emissions by 2050: A Critical Review
May 2023
Publication
Hydrogen (H2) usage was 90 metric tonnes (Mt) in 2020 almost entirely for industrial and refining uses and generated almost completely from fossil fuels leading to nearly 900 Mt of carbon dioxide emissions. However there has been significant growth of H2 in recent years. Electrolysers' total capacity which are required to generate H2 from electricity has multiplied in the past years reaching more than 300 MW through 2021. Approximately 350 projects reportedly under construction could push total capacity to 54 GW by the year 2030. Some other 40 projects totalling output of more than 35 GW are in the planning phase. If each of these projects is completed global H2 production from electrolysers could exceed 8 Mt by 2030. It's an opportunity to take advantage of H2S prospects to be a crucial component of a clean safe and cost-effective sustainable future. This paper assesses the situation regarding H2 at the moment and provides recommendations for its potential future advancement. The study reveals that clean H2 is experiencing significant unparalleled commercial and political force with the amount of laws and projects all over the globe growing quickly. The paper concludes that in order to make H2 more widely employed it is crucial to significantly increase innovations and reduce costs. The practical and implementable suggestions provided to industries and governments will allow them to fully capitalise on this growing momentum.
Everything About Hydrogen Podcast: Policy Simplicity & Certainty
Mar 2023
Publication
On this episode of Everything About Hydrogen we have Daria Nochevnik the Director of Policy and Partnerships for Hydrogen Council.
The podcast can be found on their website.
The podcast can be found on their website.
A Global Review of the Hydrogen Energy Eco-System
Feb 2023
Publication
Climate change primarily caused by the greenhouse gases emitted as a result of the consumption of carbon-based fossil fuels is considered one of the biggest challenges that humanity has ever faced. Moreover the Ukrainian crisis in 2022 has complicated the global energy and food status quo more than ever. The permanency of this multifaceted fragility implies the need for increased efforts to have energy independence and requires long-term solutions without fossil fuels through the use of clean zero-carbon renewables energies. Hydrogen technologies have a strong potential to emerge as an energy eco-system in its production-storage-distribution-utilization stages with its synergistic integration with solar-wind-hydraulic-nuclear and other zero-carbon clean renewable energy resources and with the existing energy infrastructure. In this paper we provide a global review of hydrogen energy need related policies practices and state of the art for hydrogen production transportation storage and utilization.
How a Grid Company Could Enter the Hydrogen Industry through a New Business Model: A Case Study in China
Mar 2023
Publication
The increasing penetration of renewable and distributed resources signals a global boom in energy transition but traditional grid utilities have yet to share in much of the triumph at the current stage. Higher grid management costs lower electricity prices fewer customers and other challenges have emerged along the path toward renewable energy but many more opportunities await to be seized. Most importantly there are insufficient studies on how grid utilities can thrive within the hydrogen economy. Through a case study on the State Grid Corporation of China we identify the strengths weaknesses opportunities and threats (SWOT) of grid utilities within the hydrogen economy. Based on these factors we recommend that grids integrate hydrogen into the energy-as-a-service model and deliver it to industrial customers who are under decarbonization pressure. We also recommend that grid utilities fund a joint venture with pipeline companies to optimize electricity and hydrogen transmissions simultaneously.
Impacts of Green Hydrogen for Steel, Ammonia, and Long-distance Transport on the Cost of Meeting Electricity, Heat, Cold, and Hydrogen Demand in 145 Countries Running on 100% Wind-water-solar
May 2023
Publication
As the world moves to clean renewable energy questions arise as to how best to produce and use hydrogen. Here we propose using hydrogen produced only by electrolysis with clean renewable electricity (green hydrogen). We then test the impact of producing such hydrogen intermittently versus continuously for steel and ammonia manufacturing and long-distance transport via fuel cells on the cost of matching electricity heat cold and hydrogen demand with supply and storage on grids worldwide. An estimated 79 32 and 91 Tg-H2/y of green hydrogen are needed in 2050 among 145 countries for steel ammonia and long-distance transport respectively. Producing and compressing such hydrogen for these processes may consume ~12.1% of the energy needed for end-use sectors in these countries after they transition to 100% wind-water-solar (WWS) in all such sectors. This is less than the energy needed for fossil fuels to power the same processes. Due to the variability of WWS electricity producing green hydrogen intermittently rather than continuously thus with electrolyzer use factors significantly below unity (0.2–0.65) may reduce overall energy costs with 100% WWS. This result is subject to model uncertainties but appears robust. In sum grid operators should incorporate intermittent green hydrogen production and use in planning.
Designing Off-grid Green Hydrogen Plants Using Dynamic Polymer Electrolyte Membrane Electrolyzers to Minimize the Hydrogen Production Cost
Oct 2023
Publication
Hydrogen produced from electrolysis is an attractive carbon-free fuel and feedstock but potential benefits depend on the carbon intensity of electricity production. This study uses technoeconomic modeling to analyze the benefits of producing zero-carbon hydrogen through dynamically operated polymer electrolyte membrane electrolyzers connected to photovoltaic and wind variable renewable energy (VRE) sources. Dynamic operation is considered for current densities between 0 and 6 A cm2 and compared to a constant current density of 2 A cm2 for different combinations of VRE to electrolysis (VRE:E) capacity ratios and compositions of photovoltaic and wind energy in four locations across the United States. For optimal VRE:E and wind:photovoltaic capacity ratios dynamic operation is found to reduce the levelized cost of hydrogen by 5%–9% while increasing hydrogen production by 134%–173% and decreasing excess electrical power by 82%–95%. The framework herein may be used to determine the optimal VRE:E capacity and VRE mix for dynamically operated green hydrogen systems.
Integrated Power and Propulsion System Optimization for a Planetary-Hopping Robot
Aug 2022
Publication
Missions targeting the extreme and rugged environments on the moon and Mars have rich potential for a high science return although several risks exist in performing these exploration missions. The current generation of robots is unable to access these high-priority targets. We propose using teams of small hopping and rolling robots called SphereX that are several kilograms in mass and can be carried by a large rover or lander and tactically deployed for exploring these extreme environments. Considering that the importance of minimizing the mass and volume of these robot platforms translates into significant mission-cost savings we focus on the optimization of an integrated power and propulsion system for SphereX. Hydrogen is used as fuel for its high energy and it is stored in the form of lithium hydride and oxygen in the form of lithium perchlorate. The system design undergoes optimization using Genetic Algorithms integrated with gradient-based search techniques to find optimal solutions for a mission. Our power and propulsion system as we show in this paper is enabling because the robots can travel long distances to perform science exploration by accessing targets not possible with conventional systems. Our work includes finding the optimal mass and volume of SphereX such that it can meet end-to-end mission requirements.
Production of Hydrogen from Offshore Wind in China and Cost-competitive Supply to Japan
Nov 2021
Publication
The Japanese government has announced a commitment to net-zero greenhouse gas emissions by 2050. It envisages an important role for hydrogen in the nation’s future energy economy. This paper explores the possibility that a significant source for this hydrogen could be produced by electrolysis fueled by power generated from offshore wind in China. Hydrogen could be delivered to Japan either as liquid or bound to a chemical carrier such as toluene or as a component of ammonia. The paper presents an analysis of factors determining the ultimate cost for this hydrogen including expenses for production storage conversion transport and treatment at the destination. It concludes that the Chinese source could be delivered at a volume and cost consistent with Japan’s idealized future projections.
Green Hydrogen Supply Chain Risk Analysis: A European Hard-to-abate Sectors Perspective
May 2023
Publication
Green hydrogen is a tentative solution for the decarbonisation of hard-to-abate sectors such as steel chemical cement and refinery industries. Green hydrogen is a form of hydrogen gas that is produced using renewable energy sources such as wind or solar power through a process called electrolysis. The green hydrogen supply chain includes several interconnected entities such as renewable energy providers electrolysers distribution facilities and consumers. Although there have been many studies about green hydrogen little attention has been devoted to green hydrogen supply chain risk identification and analysis especially for hard-to-abate sectors in Europe. This research contributes to existing knowledge by identifying and analysing the European region’s green hydrogen supply chain risk factors. Using a Delphi method 7 categories and 43 risk factors are identified based on the green hydrogen supply chain experts’ opinions. The best-worst method is utilised to determine the importance weights of the risk categories and risk factors. High investment of capital for hydrogen production and delivery technology was the highest-ranked risk factor followed by the lack of enough capacity for electrolyser and policy & regulation development. Several mitigation strategies and policy recommendations are proposed for high-importance risk factors. This study provides novelty in the form of an integrated approach resulting in a scientific ranking of the risk factors for the green hydrogen supply chain. The results of this study provide empirical evidence which corroborates with previous studies that European countries should endeavour to create comprehensive and supportive standards and regulations for green hydrogen supply chain implementation.
A Systematic Review: The Role of Emerging Carbon Capture and Conversion Rechnologies for Energy Transition to Clean Hydrogen
Feb 2024
Publication
The exploitation of fossil fuels in various sectors such as power and heat generation and the transportation sector has been the primary source of greenhouse gas (GHG) emissions which are the main contributors to global warming. Qatar's oil and gas sector notably contributes to CO2 emissions accounting for half of the total emissions. Globally it is essential to transition into cleaner fossil fuel production to achieve carbon neutrality on a global scale. In this paper we focus on clean hydrogen considering carbon capture to make hydrogen a viable low carbon energy alternative for the transition to clean energy. This paper systematically reviews emerging technologies in carbon capture and conversion (CCC). First the road map stated by the Intergovernmental Panel on Climate Change (IPCC) to reach carbon neutrality is discussed along with pathways to decarbonize the energy sector in Qatar. Next emerging CO2 removal technologies including physical absorption using ionic liquids chemical looping and cryogenics are explored and analyzed regarding their advancement and limitations CO2 purity scalability and prospects. The advantages limitations and efficiency of the CO2 conversion technology to value-added products are grouped into chemical (plasma catalysis electrochemical and photochemical) and biological (photosynthetic and non-photosynthetic). The paper concludes by analyzing pathways to decarbonize the energy sector in Qatar via coupling CCC technologies for low-carbon hydrogen highlighting the challenges and research gaps.
Route-to-Market Strategy for Low-carbon Hydrogen from Natural Gas in the Permian Basin
Aug 2023
Publication
This paper investigates the untapped potential of the Permian Basin a multifaceted energy axis in Texas and adjoining states in the emerging era of decarbonization. Aligned with current policy directives on regional hydrogen hubs this study explores the viability of developing a hydrogen energy hub in the Permian Basin thereby producing low-carbon intensity hydrogen from natural gas in the Basin and transporting it to the Greater Houston area. Diverging from existing literature this study provides an integrated techno-economic evaluation of the entire hydrogen value chain in the Permian Basin encompassing production storage and transportation. Furthermore it comparatively analyzes the scenario of interest against an optimized base scenario thereby underlining comparative advantages and disadvantages. The paper concludes that the delivered cost of Permian based low-carbon intensity hydrogen to the Greater Houston area is $1.85/kg benchmarked to the scenario with hydrogen produced close to the Greater Houston area and delivered at $1.42/kg. Our findings reveal that Permian-based low-carbon intensity hydrogen production can achieve cost savings in feedstock ($0.25/kg) and potentially accrue a higher production tax credit due to a shorter gas supply chain to production ($0.33/kg). Nevertheless a significant cost barrier is the expense of long-haul pipeline transport ($0.90/kg) from the Permian Basin to Houston as opposed to local production. Despite the obstacles the study identifies a potential breakeven solution where increasing the production scale to at least 412000 metric ton per year (about 3 steam reforming plants) in the Permian Basin can effectively lower costs in the transport sector. Hence a scaled-up production can mitigate the cost difference and establish the Permian Basin as a competitive player in the hydrogen market. In conclusion a SWOT analysis presents Strengths Weaknesses Opportunities and Threats associated with Permian-based hydrogen production.
Hydrogen Liquefaction: A Review of the Fundamental Physics, Engineering Practice and Future Opportunities
Apr 2022
Publication
Hydrogen is emerging as one of the most promising energy carriers for a decarbonised global energy system. Transportation and storage of hydrogen are critical to its large-scale adoption and to these ends liquid hydrogen is being widely considered. The liquefaction and storage processes must however be both safe and efficient for liquid hydrogen to be viable as an energy carrier. Identifying the most promising liquefaction processes and associated transport and storage technologies is therefore crucial; these need to be considered in terms of a range of interconnected parameters ranging from energy consumption and appropriate materials usage to considerations of unique liquid-hydrogen physics (in the form of ortho–para hydrogen conversion) and boil-off gas handling. This study presents the current state of liquid hydrogen technology across the entire value chain whilst detailing both the relevant underpinning science (e.g. the quantum behaviour of hydrogen at cryogenic temperatures) and current liquefaction process routes including relevant unit operation design and efficiency. Cognisant of the challenges associated with a projected hydrogen liquefaction plant capacity scale-up from the current 32 tonnes per day to greater than 100 tonnes per day to meet projected hydrogen demand this study also reflects on the next-generation of liquid-hydrogen technologies and the scientific research and development priorities needed to enable them.
Breaking the Hard-to-abate Bottleneck in China’s Path to Carbon Neutrality with Clean Hydrogen
Sep 2022
Publication
Countries such as China are facing a bottleneck in their paths to carbon neutrality: abating emissions in heavy industries and heavy-duty transport. There are few in-depth studies of the prospective role for clean hydrogen in these ‘hard-to-abate’ (HTA) sectors. Here we carry out an integrated dynamic least-cost modelling analysis. Results show that first clean hydrogen can be both a major energy carrier and feedstock that can significantly reduce carbon emissions of heavy industry. It can also fuel up to 50% of China’s heavy-duty truck and bus fleets by 2060 and significant shares of shipping. Second a realistic clean hydrogen scenario that reaches 65.7 Mt of production in 2060 could avoid US$1.72 trillion of new investment compared with a no-hydrogen scenario. This study provides evidence of the value of clean hydrogen in HTA sectors for China and countries facing similar challenges in reducing emissions to achieve net-zero goals.
Technological Pathways for Decarbonizing Petroleum Refining
Sep 2021
Publication
This paper discusses the technical specifications of how U.S. petroleum refineries can reduce facility emissions and shift to produce low-carbon fuels for hard to abate sectors by utilizing existing innovative technologies.
Water Consumption from Electrolytic Hydrogen in a Carbon-neutral US Energy System
Feb 2023
Publication
Hydrogen is an energy carrier with potential applications in decarbonizing difficult-to-electrify energy and industrial systems. The environmental profile of hydrogen varies substantially with its inputs. Water consumption is a particular issue of interest as decisions are made about capital and other investments that will affect the scale and scope of hydrogen use. This study focuses on electrolytic hydrogen due to its path to greenhouse gas neutrality and irreducible water demand (though other pathways might be more water intensive). Specifically it evaluates life cycle consumptive freshwater intensity of electrolytic hydrogen in the United States at volumes associated with 12 scenarios for a deeply decarbonized 2050 US energy system from two modeling efforts for which both electricity fuel mix and electrolytic hydrogen production were projected (America’s Zero Carbon Action Plan and Net Zero America) in addition to volumes for a stylized energy storage project (500 MW hydrogen-fired turbine). Freshwater requirements for hydrogen could be large. Under a central estimate for 2050 US electrolytic hydrogen production electrolytic freshwater demand for process and feedstock inputs alone (i.e. excluding water for electricity) would be about 7.5% of total 2014 US freshwater consumption for energy (1 billion cubic meters/year 109 m3 /y; [0.2% 15%] across scenarios for 2050 electrolytic hydrogen production of [0.3 18] exajoules EJ). Including water associated with production of input electricity doubles this central estimate to 15% (2 × 109 m3 /y; [1% 23%] across scenarios). Turbines using electrolytic hydrogen are estimated to be about as freshwater intensive as a coal or nuclear plant assuming decarbonized low-water electricity inputs. Although a decarbonized energy system is projected to require less water for resource capture and electricity conversion than the current fossil-dominated energy system additional conversion processes supporting decarbonization like electrolysis could offset water savings.
Modelling Underground Hydrogen Storage: A State-of-the-art Review of Fundamental Approaches and Findings
Dec 2023
Publication
This review presents a state-of-the-art of geochemical geomechanical and hydrodynamic modelling studies in the Underground Hydrogen Storage (UHS) domain. Geochemical modelling assessed the reactivity of hydrogen and res pective fluctuations in hydrogen losses using kinetic reaction rates rock mineralogy brine salinity and the integration of hydrogen redox reactions. Existing geomechanics studies offer an array of coupled hydromechanical models suggesting a decline in rock failure during the withdrawal phase in aquifers compared to injection phase. Hydrodynamic modelling evaluations indicate the critical importance of relative permeability hysteresis in determining the UHS performance. Solubility and diffusion of hydrogen gas appear to have minimal impact on UHS. Injection and production rates cushion gas deployment and reservoir heterogeneity however significantly affect the UHS performance stressing the need for thorough modelling and experimental studies. Most of the current UHS modelling efforts focus on assessing the hydrodynamic aspects which are crucial for understanding the viability and safety of UHS. In contrast the lesser-explored geochemical and geomechanical considerations point to potential research gaps. A variety of modelling software tools such as CMG Eclipse COMSOL and PHREEQC evaluated those UHS underlying effects along with a few recent applications of datadriven-based Machine Learning (ML) techniques for enhanced accuracy. This review identified several unresolved challenges in UHS modelling: pronounced lack of expansive datasets leading to a gap between model predictions and their practical reliability; need robust methodologies capable of capturing natural subsurface heterogeneity while upscaling from precise laboratory data to field-scale conditions; demanding intensive computational resources and novel strategies to enhance simulation efficiency; and a gap in addressing geological uncertainties in subsurface environments suggesting that methodologies from oil reservoir simulations could be adapted for UHS. This comprehensive review offers a critical synthesis of the prevailing approaches challenges and research gaps in the domain of UHS thus providing a valuable reference document for further modelling efforts facilitating the informed advancements in this critical domain towards the realization of sustainable energy solutions.
Deploying Green Hydrogen to Decarbonize China's Coal Chemical Sector
Dec 2023
Publication
China’s coal chemical sector uses coal as both a fuel and feedstock and its increasing greenhouse gas (GHG) emissions are hard to abate by electrification alone. Here we explore the GHG mitigation potential and costs for onsite deployment of green H2 and O2 in China’s coal chemical sector using a lifecycle assessment and techno-economic analyses. We estimate that China’s coal chemical production resulted in GHG emissions of 1.1 gigaton CO2 equivalent (GtCO2eq) in 2020 equal to 9% of national emissions. We project GHG emissions from China’s coal chemical production in 2030 to be 1.3 GtCO2eq ~50% of which can be reduced by using solar or wind power-based electrolytic H2 and O2 to replace coal-based H2 and air separation-based O2 at a cost of 10 or 153 Chinese Yuan (CNY)/tCO2eq respectively. We suggest that provincial regions determine whether to use solar or wind power for water electrolysis based on lowest cost options which collectively reduce 53% of the 2030 baseline GHG emissions at a cost of 9 CNY/tCO2eq. Inner Mongolia Shaanxi Ningxia and Xinjiang collectively account for 52% of total GHG mitigation with net cost reductions. These regions are well suited for pilot policies to advance demonstration projects.
Global Land and Water Limits to Electrolytic Hydrogen Production Using Wind and Solar Resources
Sep 2023
Publication
Proposals for achieving net-zero emissions by 2050 include scaling-up electrolytic hydrogen production however this poses technical economic and environmental challenges. One such challenge is for policymakers to ensure a sustainable future for the environment including freshwater and land resources while facilitating low-carbon hydrogen production using renewable wind and solar energy. We establish a country-by-country reference scenario for hydrogen demand in 2050 and compare it with land and water availability. Our analysis highlights countries that will be constrained by domestic natural resources to achieve electrolytic hydrogen self-sufficiency in a net-zero target. Depending on land allocation for the installation of solar panels or wind turbines less than 50% of hydrogen demand in 2050 could be met through a local production without land or water scarcity. Our findings identify potential importers and exporters of hydrogen or conversely exporters or importers of industries that would rely on electrolytic hydrogen. The abundance of land and water resources in Southern and Central-East Africa West Africa South America Canada and Australia make these countries potential leaders in hydrogen export.
Fuelling the Future: An In-depth Review of Recent Trends, Challenges and Opportunities of Hydrogen Fuel Cell for a Sustainable Hydrogen Economy
Sep 2023
Publication
Hydrogen has gained tremendous momentum worldwide as an energy carrier to transit to a net zero emission energy sector. It has been widely adopted as a promising large-scale renewable energy (RE) storage solution to overcome RE resources’ variability and intermittency nature. The fuel cell (FC) technology became in focus within the hydrogen energy landscape as a cost-effective pathway to utilize hydrogen for power generation. Therefore FC technologies’ research and development (R&D) expanded into many pathways such as cost reduction efficiency improvement fixed and mobile applications lifetime safety and regulations etc. Many publications and industrial reports about FC technologies and applications are available. This raised the necessity for a holistic review study to summarize the state-of-the-art range of FC stacks such as manufacturing the balance of plant types technologies applications and R&D opportunities. At the beginning the principal technologies to compare the well known types followed by the FC operating parameters are presented. Then the FC balance of the plant i.e. building components and materials with its functionality and purpose types and applications are critically reviewed with their limitations and improvement opportunities. Subsequently the electrical properties of FCs with their key features including advantages and disadvantages were investigated. Applications of FCs in different sectors are elaborated with their key characteristics current status and future R&D opportunities. Economic attributes of fuel cells with a pathway towards low cost are also presented. Finally this study identifies the research gaps and future avenues to guide researchers and the hydrogen industry.
Renewable-power-assisted Production of Hydrogen and Liquid Hydrocarbons from Natural Gas: Techno-economic Analysis
Jun 2022
Publication
The declining cost of renewable power has engendered growing interest in leveraging this power for the production of chemicals and synthetic fuels. Here renewable power is added to the gas-to-liquid (GTL) process through Fischer–Tropsch (FT) synthesis in order to increase process efficiency and reduce CO2 emissions. Accordingly two realistic configurations are considered which differ primarily in the syngas preparation step. In the first configuration solid oxide steam electrolysis cells (SOEC) in combination with an autothermal reformer (ATR) are used to produce synthesis gas with the right composition while in the second configuration an electrically-heated steam methane reformer (E-SMR) is utilized for syngas production. The results support the idea of adding power to the GTL process mainly by increased process efficiencies and reduced process emissions. Assuming renewable power is available the process emissions would be 200 and 400 gCO2 L1 syncrude for the first and second configurations respectively. Configuration 1 and 2 show 8 and 4 times less emission per liter syncrude produced respectively compared to a GTL plant without H2 addition with a process emission of 1570 gCO2 L1 syncrude. By studying the two designs based on FT production carbon efficiency and FT catalyst volume a better alternative is to add renewable power to the SOEC (configuration 1) rather than using it in an E-SMR (configuration 2). Given an electricity price of $100/MW h and natural gas price of 5 $ per GJ FT syncrude and H2 can be produced at a cost between $15/MW h and $16/MW h. These designs are considered to better utilize the available carbon resources and thus expedite the transition to a low-carbon economy
An Exploration of Safety Measures in Hydrogen Refueling Stations: Delving into Hydrogen Equipment and Technical Performance
Feb 2024
Publication
The present paper offers a thorough examination of the safety measures enforced at hydrogen filling stations emphasizing their crucial significance in the wider endeavor to advocate for hydrogen as a sustainable and reliable substitute for conventional fuels. The analysis reveals a wide range of crucial safety aspects in hydrogen refueling stations including regulated hydrogen dispensing leak detection accurate hydrogen flow measurement emergency shutdown systems fire-suppression mechanisms hydrogen distribution and pressure management and appropriate hydrogen storage and cooling for secure refueling operations. The paper therefore explores several aspects including the sophisticated architecture of hydrogen dispensers reliable leak-detection systems emergency shut-off mechanisms and the implementation of fire-suppression tactics. Furthermore it emphasizes that the safety and effectiveness of hydrogen filling stations are closely connected to the accuracy in the creation and upkeep of hydrogen dispensers. It highlights the need for materials and systems that can endure severe circumstances of elevated pressure and temperature while maintaining safety. The use of sophisticated leak-detection technology is crucial for rapidly detecting and reducing possible threats therefore improving the overall safety of these facilities. Moreover the research elucidates the complexities of emergency shut-off systems and fire-suppression tactics. These components are crucial not just for promptly managing hazards but also for maintaining the station’s structural soundness in unanticipated circumstances. In addition the study provides observations about recent technical progress in the industry. These advances effectively tackle current safety obstacles and provide the foundation for future breakthroughs in hydrogen fueling infrastructure. The integration of cutting-edge technology and materials together with the development of upgraded safety measures suggests a positive trajectory towards improved efficiency dependability and safety in hydrogen refueling stations.
Hydrogen Station Prognostics and Health Monitoring Model
Aug 2023
Publication
Hydrogen fuel has shown promise as a clean alternative fuel aiding in the reduction of fossil fuel dependence within the transportation sector. However hydrogen refueling stations and infrastructure remains a barrier and are a prerequisite for consumer adoption of low-cost and low-emission fuel cell electric vehicles (FCEVs). The costs for FCEV fueling include both station capital costs and operation and maintenance (O&M) costs. Contributing to these O&M costs unscheduled maintenance is presently more costly and more frequent than for similar gasoline fueling infrastructure and is asserted to be a limiting factor in achieving FCEV customer acceptance and cost parity. Unscheduled maintenance leads to longer station downtime therefore causing an increase in missed fueling opportunities which forces customers to seek refueling at other operable stations that may be significantly farther away. This research proposes a framework for a hydrogen station prognostics health monitoring (H2S PHM) model that can minimize unexpected downtime by predicting the remaining useful life for primary hydrogen station components within the major station subsystems. The H2S PHM model is a data-driven statistical model based on O&M data collected from 34 retail hydrogen stations located in the U.S. The primary subcomponents studied are the dispenser compressor and chiller. The remaining useful life calculations are used to decide whether or not maintenance should be completed based on the prediction and expected future station use. This paper presents the background method and results for the H2S PHM model as for a means for improving station availability and customer confidence in FCEVs and hydrogen infrastructure
Preliminary Study for the Commercialization of a Electrochemical Hydrogen Compressor
Mar 2023
Publication
A global energy shift to a carbon‐neutral society requires clean energy. Hydrogen can accelerate the process of expanding clean and renewable energy sources. However conventional hydrogen compression and storage technology still suffers from inefficiencies high costs and safety concerns. An electrochemical hydrogen compressor (EHC) is a device similar in structure to a water electrolyzer. Its most significant advantage is that it can accomplish hydrogen separation and compression at the same time. With no mechanical motion and low energy consumption the EHC is the key to future hydrogen compression and purification technology breakthroughs. In this study the compression performance efficiency and other related parameters of EHC are investigated through experiments and simulation calculations. The experimental results show that under the same experimental conditions increasing the supply voltage and the pressure in the anode chamber can improve the reaction rate of EHC and balance the pressure difference between the cathode and anode. The presence of residual air in the anode can impede the interaction between hydrogen and the catalyst as well as the proton exchange membrane (PEM) resulting in a decrease in performance. In addition it was found that a single EHC has a better compression ratio and reaction rate than a double EHC. The experimental results were compatible with the theoretical calculations within less than a 7% deviation. Finally the conditions required to reach commercialization were evaluated using the theoretical model.
U.S. National Clean Hydrogen Strategy and Roadmap
Jun 2023
Publication
The U.S. National Clean Hydrogen Strategy and Roadmap explores opportunities for clean hydrogen to contribute to national decarbonization goals across multiple sectors of the economy. It provides a snapshot of hydrogen production transport storage and use in the United States today and presents a strategic framework for achieving large-scale production and use of clean hydrogen examining scenarios for 2030 2040 and 2050.
The Strategy and Roadmap also identifies needs for collaboration among federal government agencies industry academia national laboratories state local and Tribal communities environmental and justice communities labor unions and numerous stakeholder groups to accelerate progress and market liftoff. This roadmap establishes concrete targets market-driven metrics and tangible actions to measure success across sectors.
The Strategy and Roadmap responds to legislative language set forth in section 40314 of the Infrastructure Investment and Jobs Act (Public Law 117-58) also known as the Bipartisan Infrastructure Law (BIL). This document was posted for in draft form for public comment in September 2022 and the final version of the report was informed by stakeholder feedback further analysis on market liftoff as well as engagement across several federal agencies and the White House Climate Policy Office. There will also be future opportunities for stakeholder feedback as the report will be updated at least every three years as required by the BIL.
The report can be found on their website.
The Strategy and Roadmap also identifies needs for collaboration among federal government agencies industry academia national laboratories state local and Tribal communities environmental and justice communities labor unions and numerous stakeholder groups to accelerate progress and market liftoff. This roadmap establishes concrete targets market-driven metrics and tangible actions to measure success across sectors.
The Strategy and Roadmap responds to legislative language set forth in section 40314 of the Infrastructure Investment and Jobs Act (Public Law 117-58) also known as the Bipartisan Infrastructure Law (BIL). This document was posted for in draft form for public comment in September 2022 and the final version of the report was informed by stakeholder feedback further analysis on market liftoff as well as engagement across several federal agencies and the White House Climate Policy Office. There will also be future opportunities for stakeholder feedback as the report will be updated at least every three years as required by the BIL.
The report can be found on their website.
Critical Mineral Demands May Limit Scaling of Green Hydrogen Production
Jan 2024
Publication
Hydrogen (H2) is widely viewed as critical to the decarbonization of industry and transportation. Water electrolysis powered by renewable electricity commonly referred to as green H2 can be used to generate H2 with low carbon dioxide emissions. Herein we analyze the critical mineral and energy demands associated with green H2 production under three different hypothetical future demand scenarios ranging from 100–1000 Mtpa H2. For each scenario we calculate the critical mineral demands required to build water electrolyzers (i.e. electrodes and electrolyte) and to build dedicated or additional renewable electricity sources (i.e. wind and solar) to power the electrolyzers. Our analysis shows that scaling electrolyzer and renewable energy technologies that use platinum group metals and rare earth elements will likely face supply constraints. Specifically larger quantities of lanthanum yttrium or iridium will be needed to increase electrolyzer capacity and even more neodymium silicon zinc molybdenum aluminum and copper will be needed to build dedicated renewable electricity sources. We find that scaling green H2 production to meet projected netzero targets will require ~24000 TWh of dedicated renewable energy generation which is roughly the total amount of solar and wind projected to be on the grid in 2050 according to some energy transition models. In summary critical mineral constraints may hinder the scaling of green H2 to meet global net-zero emissions targets motivating the need for the research and development of alternative lowemission methods of generating H2
Review of Sampling and Analysis of Particulate Matter in Hydrogen Fuel
Sep 2023
Publication
This review presents state-of-the-art for representative sampling of hydrogen from hydrogen refueling stations. Documented sampling strategies are presented as well as examples of commercially available equipment for sampling at the hydrogen refueling nozzle. Filter media used for sampling is listed and the performance of some of the filters evaluated. It was found that the filtration efficiency of 0.2 and 5 mm filters were not significantly different when exposed to 200 and 300 nm particles. Several procedures for gravimetric analysis are presented and some of the challenges are identified to be filter degradation pinhole formation and conditioning of the filter prior to measurement. Lack of standardization of procedures was identified as a limitation for result comparison. Finally the review summarizes results including particulate concentration in hydrogen fuel quality data published. It was found that less than 10% of the samples were in violation with the tolerance limit.
Adaptive Network Fuzzy Inference System and Particle Swarm Optimization of Biohydrogen Production Process
Sep 2022
Publication
Green hydrogen is considered to be one of the best candidates for fossil fuels in the near future. Bio-hydrogen production from the dark fermentation of organic materials including organic wastes is one of the most cost-effective and promising methods for hydrogen production. One of the main challenges posed by this method is the low production rate. Therefore optimizing the operating parameters such as the initial pH value operating temperature N/C ratio and organic concentration (xylose) plays a significant role in determining the hydrogen production rate. The experimental optimization of such parameters is complex expensive and lengthy. The present research used an experimental data asset adaptive network fuzzy inference system (ANFIS) modeling and particle swarm optimization to model and optimize hydrogen production. The coupling between ANFIS and PSO demonstrated a robust effect which was evident through the improvement in the hydrogen production based on the four input parameters. The results were compared with the experimental and RSM optimization models. The proposed method demonstrated an increase in the biohydrogen production of 100 mL/L compared to the experimental results and a 200 mL/L increase compared to the results obtained using ANOVA.
Reversible Molten Catalytic Methane Cracking Applied to Commercial Solar-Thermal Receivers
Nov 2020
Publication
When driven by sunlight molten catalytic methane cracking can produce clean hydrogen fuel from natural gas without greenhouse emissions. To design solar methane crackers a canonical plug flow reactor model was developed that spanned industrially relevant temperatures and pressures (1150–1350 Kelvin and 2–200 atmospheres). This model was then validated against published methane cracking data and used to screen power tower and beam-down reactor designs based on “Solar Two” a renewables technology demonstrator from the 1990s. Overall catalytic molten methane cracking is likely feasible in commercial beam-down solar reactors but not power towers. The best beam-down reactor design was 9% efficient in the capture of sunlight as fungible hydrogen fuel which approaches photovoltaic efficiencies. Conversely the best discovered tower methane cracker was only 1.7% efficient. Thus a beam-down reactor is likely tractable for solar methane cracking whereas power tower configurations appear infeasible. However the best simulated commercial reactors were heat transfer limited not reaction limited. Efficiencies could be higher if heat bottlenecks are removed from solar methane cracker designs. This work sets benchmark conditions and performance for future solar reactor improvement via design innovation and multiphysics simulation.
Natural Hydrogen in the Energy Transition: Fundamentals, Promise, and Enigmas
Oct 2023
Publication
Beyond its role as an energy vector a growing number of natural hydrogen sources and reservoirs are being discovered all over the globe which could represent a clean energy source. Although the hydrogen amounts in reservoirs are uncertain they could be vast and they could help decarbonize energy-intensive economic sectors and facilitate the energy transition. Natural hydrogen is mainly produced through a geochemical process known as serpentinization which involves the reaction of water with low-silica ferrous minerals. In favorable locations the hydrogen produced can become trapped by impermeable rocks on its way to the atmosphere forming a reservoir. The safe exploitation of numerous natural hydrogen reservoirs seems feasible with current technology and several demonstration plants are being commissioned. Natural hydrogen may show variable composition and require custom separation purification storage and distribution facilities depending on the location and intended use. By investing in research in the mid-term more hydrogen sources could become exploitable and geochemical processes could be artificially stimulated in new locations. In the long term it may be possible to leverage or engineer the interplay between microorganisms and geological substrates to obtain hydrogen and other chemicals in a sustainable manner.
Batteries or Hydrogen or Both for Grid Electricity Storage Upon Full Electrification of 145 Countries with Wind-Water-Solar?
Jan 2024
Publication
Grids require electricity storage. Two emerging storage technologies are battery storage (BS) and green hydrogen storage (GHS) (hydrogen produced and compressed with clean-renewable electricity stored then returned to electricity with a fuel cell). An important question is whether GHS alone decreases system cost versus BS alone or BS+GHS. Here energy costs are modeled in 145 countries grouped into 24 regions. Existing conventional hydropower (CH) storage is used along with new BS and/or GHS. A method is developed to treat CH for both baseload and peaking power. In four regions only CH is needed. In five CH+BS is lowest cost. Otherwise CH+BS+GHS is lowest cost. CH+GHS is never lowest cost. A metric helps estimate whether combining GHS with BS reduces cost. In most regions merging (versus separating) grid and non-grid hydrogen infrastructure reduces cost. In sum worldwide grid stability may be possible with CH+BS or CH+BS+GHS. Results are subject to uncertainties.
Performance, Emissions, and Combustion Characteristics of a Hydrogen-Fueled Spark-Ignited Engine at Different Compression Ratios: Experimental and Numerical Investigation
Jul 2023
Publication
This paper investigates the performance of hydrogen-fueled spark-ignited single-cylinder Cooperative Fuel Research using experimental and numerical approaches. This study examines the effect of the air–fuel ratio on engine performance emissions and knock behaviour across different compression ratios. The results indicate that λ significantly affects both engine performance and emissions with a λ value of 2 yielding the highest efficiency and lowest emissions for all the tested compression ratios. Combustion analysis reveals normal combustion at λ ≥ 2 while knocking combustion occurs at λ < 2 irrespective of the tested compression ratios. The Livenwood–Wu integral approach was evaluated to assess the likelihood of end-gas autoignition based on fuel reactivity demonstrating that both normal and knocking combustion possibilities are consistent with experimental investigations. Combustion analysis at the ignition timing for maximum brake torque conditions demonstrates knock-free stable combustion up to λ = 3 with increased end-gas autoignition at lower λ values. To achieve knock-free combustion at those low λs the spark timings are significantly retarded to after top dead center crank angle position. Engine-out NOx emissions consistently increase in trend with a decrease in the air–fuel ratio of up to λ = 3 after which a distinct variation in NOx is observed with an increase in the compression ratio.
Experimental Comparison of Hydrogen Refueling with Directly Pressurized vs. Cascade Method
Aug 2023
Publication
This paper presents a comparative analysis of two hydrogen station configurations during the refueling process: the conventional “directly pressurized refueling process” and the innovative “cascade refueling process.” The objective of the cascade process is to refuel vehicles without the need for booster compressors. The experiments were conducted at the Hydrogen Research and Fueling Facility located at California State University Los Angeles. In the cascade refueling process the facility buffer tanks were utilized as high-pressure storage enabling the refueling operation. Three different scenarios were tested: one involving the cascade refueling process and two involving compressor-driven refueling processes. On average each refueling event delivered 1.6 kg of hydrogen. Although the cascade refueling process using the high-pressure buffer tanks did not achieve the pressure target it resulted in a notable improvement in the nozzle outlet temperature trend reducing it by approximately 8 ◦C. Moreover the overall hydrogen chiller load for the two directly pressurized refuelings was 66 Wh/kg and 62 Wh/kg respectively whereas the cascading process only required 55 Wh/kg. This represents a 20% and 12% reduction in energy consumption compared to the scenarios involving booster compressors during fueling. The observed refueling range of 150–350 bar showed that the cascade process consistently required 12–20% less energy for hydrogen chilling. Additionally the nozzle outlet temperature demonstrated an approximate 8 ◦C improvement within this pressure range. These findings indicate that further improvements can be expected in the high-pressure region specifically above 350 bar. This research suggests the potential for significant improvements in the high-pressure range emphasizing the viability of the cascade refueling process as a promising alternative to the direct compression approach.
Renewable Energy Sources for Green Hydrogen Generation in Colombia and Applicable Case of Studies
Nov 2023
Publication
Electrification using renewable energy sources represents a clear path toward solving the current global energy crisis. In Colombia this challenge also involves the diversification of the electrical energy sources to overcome the historical dependence on hydropower. In this context green hydrogen represents a key energy carrier enabling the storage of renewable energy as well as directly powering industrial and transportation sectors. This work explores the realistic potential of the main renewable energy sources including solar photovoltaics (8172 GW) hydropower (56 GW) wind (68 GW) and biomass (14 GW). In addition a case study from abroad is presented demonstrating the feasibility of using each type of renewable energy to generate green hydrogen in the country. At the end an analysis of the most likely regions in the country and paths to deploy green hydrogen projects are presented favoring hydropower in the short term and solar in the long run. By 2050 this energy potential will enable reaching a levelized cost of hydrogen (LCOH) of 1.7 1.5 3.1 and 1.4 USD/kg-H2 for solar photovoltaic wind hydropower and biomass respectively.
Enabling Safe and Sustainable Hydrogen Mobility: Circular Economy-Driven Management of Hydrogen Vehicle Safety
Sep 2023
Publication
Hydrogen vehicles encompassing fuel cell electric vehicles (FCEVs) are pivotal within the UK’s energy landscape as it pursues the goal of net-zero emissions by 2050. By markedly diminishing dependence on fossil fuels FCEVs including hydrogen vehicles wield substantial influence in shaping the circular economy (CE). Their impact extends to optimizing resource utilization enabling zero-emission mobility facilitating the integration of renewable energy sources supplying adaptable energy storage solutions and interconnecting diverse sectors. The widespread adoption of hydrogen vehicles accelerates the UK’s transformative journey towards a sustainable CE. However to fully harness the benefits of this transition a robust investigation and implementation of safety measures concerning hydrogen vehicle (HV) use are indispensable. Therefore this study takes a holistic approach integrating quantitative risk assessment (QRA) and an adaptive decision-making trial and evaluation laboratory (DEMATEL) framework as pragmatic instruments. These methodologies ensure both the secure deployment and operational excellence of HVs. The findings underscore that the root causes of HV failures encompass extreme environments material defects fuel cell damage delivery system impairment and storage system deterioration. Furthermore critical driving factors for effective safety intervention revolve around cultivating a safety culture robust education/training and sound maintenance scheduling. Addressing these factors is pivotal for creating an environment conducive to mitigating safety and risk concerns. Given the intricacies of conducting comprehensive hydrogen QRAs due to the absence of specific reliability data this study dedicates attention to rectifying this gap. A sensitivity analysis encompassing a range of values is meticulously conducted to affirm the strength and reliability of our approach. This robust analysis yields precise dependable outcomes. Consequently decision-makers are equipped to discern pivotal underlying factors precipitating potential HV failures. With this discernment they can tailor safety interventions that lay the groundwork for sustainable resilient and secure HV operations. Our study navigates the intersection of HVs safety and sustainability amplifying their importance within the CE paradigm. Using the careful amalgamation of QRA and DEMATEL methodologies we chart a course towards empowering decision-makers with the insights to steer the hydrogen vehicle domain to safer horizons while ushering in an era of transformative eco-conscious mobility.
Minimizing Emissions from Grid-based Hydrogen Production in the United States
Jan 2023
Publication
Low-carbon hydrogen could be an important component of a net-zero carbon economy helping to mitigate emissions in a number of hard-to-abate sectors. The United States recently introduced an escalating production tax credit (PTC) to incentivize production of hydrogen meeting increasingly stringent embodied emissions thresholds. Hydrogen produced via electrolysis can qualify for the full subsidy under current federal accounting standards if the input electricity is generated by carbon-free resources but may fail to do so if emitting resources are present in the generation mix. While use of behind-the-meter carbon-free electricity inputs can guarantee compliance with this standard the PTC could also be structured to allow producers using grid-supplied electricity to qualify subject to certain clean energy procurement requirements. Herein we use electricity system capacity expansion modeling to quantitatively assess the impact of grid-connected electrolysis on the evolution of the power sector in the western United States through 2030 under multiple possible implementations of the clean hydrogen PTC. We find that subsidized grid-connected hydrogen production has the potential to induce additional emissions at effective rates worse than those of conventional fossil-based hydrogen production pathways. Emissions can be minimized by requiring grid-based hydrogen producers to match 100% of their electricity consumption on an hourly basis with physically deliverable ‘additional’ clean generation which ensures effective emissions rates equivalent to electrolysis exclusively supplied by behind-the-meter carbon-free generation. While these requirements cannot eliminate indirect emissions caused by competition for limited clean resources which we find to be a persistent result of large hydrogen production subsidies they consistently outperform alternative approaches relying on relaxed time matching or marginal emissions accounting. Added hydrogen production costs from enforcing an hourly matching requirement rather than no requirements are less than $1 kg−1 and can be near zero if clean firm electricity resources are available for procurement.
Energy Transition Technology Comes With New Process Safety Challenges and Risks
Jul 2023
Publication
This paper intends to give an impression of new technologies and processes that are in development for application to achieve decarbonization and about which less or no experience on associated hazards exists in the process industry. More or less an exception is hydrogen technology because its hazards are relatively known and there is industry experience in handling it safely but problems will arise when it is produced stored and distributed on a large scale. So when its use spreads to communities and it becomes as common as natural gas now measures to control the risks will be needed. And even with hydrogen surprise findings have been shown lately e.g. its BLEVE behavior when in a liquified form stored in a vessel heated externally. Substitutes for hydrogen are not without hazard concern either. The paper will further consider the hazards of energy storage in batteries and the problems to get those hazards under control. Relatively much attention will be paid to the electrification of the process industry. Many new processes are being researched which given green energy will be beneficial to reduce greenhouse gases and enhance sustainability but of which hazards are rather unknown. Therefore as last chapter the developments with respect to the concept of hazard identification and scenario definition will be considered in quite detail. Improvements in that respect are also being possible due to the digitization of the industry and the availability of data and considering the entire life cycle all facilitated by the data model standard ISO 15926 with the scope of integration of life-cycle data for process plants including oil and gas production facilities. Conclusion is that the new technologies and processes entail new process and personal hazards and that much effort is going into renewal but safety analyses are scarce. Right in a period of process renewal attention should be focused on possibilities to implement inherently safer design.
A Cost Comparison of Various Hourly-reliable and Net-zero Hydrogen Production Pathways in the United States
Nov 2023
Publication
Hydrogen (H2) as an energy carrier may play a role in various hard-to-abate subsectors but to maximize emission reductions supplied hydrogen must be reliable low-emission and low-cost. Here we build a model that enables direct comparison of the cost of producing net-zero hourly-reliable hydrogen from various pathways. To reach net-zero targets we assume upstream and residual facility emissions are mitigated using negative emission technologies. For the United States (California Texas and New York) model results indicate nextdecade hybrid electricity-based solutions are lower cost ($2.02-$2.88/kg) than fossil-based pathways with natural gas leakage greater than 4% ($2.73-$5.94/ kg). These results also apply to regions outside of the U.S. with a similar climate and electric grid. However when omitting the net-zero emission constraint and considering the U.S. regulatory environment electricity-based production only achieves cost-competitiveness with fossil-based pathways if embodied emissions of electricity inputs are not counted under U.S. Tax Code Section 45V guidance.
A Comparative Analysis of Different Hydrogen Production Methods and Their Environmental Impact
Nov 2023
Publication
This study emphasises the growing relevance of hydrogen as a green energy source in meeting the growing need for sustainable energy solutions. It foregrounds the importance of assessing the environmental consequences of hydrogen-generating processes for their long-term viability. The article compares several hydrogen production processes in terms of scalability costeffectiveness and technical improvements. It also investigates the environmental effects of each approach considering crucial elements such as greenhouse gas emissions water use land needs and waste creation. Different industrial techniques have distinct environmental consequences. While steam methane reforming is cost-effective and has a high production capacity it is coupled with large carbon emissions. Electrolysis a technology that uses renewable resources is appealing but requires a lot of energy. Thermochemical and biomass gasification processes show promise for long-term hydrogen generation but further technological advancement is required. The research investigates techniques for improving the environmental friendliness of hydrogen generation through the use of renewable energy sources. Its ultimate purpose is to offer readers a thorough awareness of the environmental effects of various hydrogen generation strategies allowing them to make educated judgements about ecologically friendly ways. It can ease the transition to a cleaner hydrogen-powered economy by considering both technological feasibility and environmental issues enabling a more ecologically conscious and climate-friendly energy landscape.
Modelling Flexibility Requirements in Deep Decarbonisation Scenarios: The Role of Conventional Flexibility and Sector Coupling Options in the European 2050 Energy System
Feb 2024
Publication
Russia’s invasion of Ukraine has reaffirmed the importance of scaling up renewable energy to decarbonise Europe’s economy while rapidly reducing its exposure to foreign fossil fuel suppliers. Therefore the question of sources of flexibility to support a fully decarbonised European energy system is becoming even more critical in light of a renewable-dominated energy system. We developed and used a Pan-European energy system model to systematically assess and quantify sources of flexibility to meet deep decarbonisation targets. The electricity supply sector and electricity-based end-use technologies are crucial in achieving deep decarbonisation. Other low-carbon energy sources like biomethane hydrogen synthetic e-fuels and bioenergy with carbon capture and storage will also play a role. To support a fully decarbonised European energy system by 2050 both temporal and spatial flexibility will be needed. Spatial flexibility achieved through investments in national electricity networks and cross-border interconnections is crucial to support the aggressive roll-out of variable renewable energy sources. Cross-border trade in electricity is expected to increase and in deep decarbonisation scenarios the electricity transmission capacity will be larger than that of natural gas. Hydrogen storage and green hydrogen production will play a key role in providing traditional inter-seasonal flexibility and intraday flexibility will be provided by a combination of electrical energy storage hydrogen-based storage solutions (e.g. liquid H2 and pressurised storage) and hybrid heat pumps. Hydrogen networks and storage will become more critical as we move towards the highest decarbonisation scenario. Still the need for natural gas networks and storage will decrease substantially.
Market-based Asset Valuation of Hydrogen Geological Storage
Jul 2023
Publication
Because of hydrogen's low energy density hydrogen storage is a critical component of the hydrogen economy particularly when large-scale and flexible hydrogen utilization is required. There is a sense of urgency to develop hydrogen geological storage projects to support large-scale yet flexible hydrogen utilization. This study aims to answer questions not yet resolved in the research literature discussing the valuation of hydrogen geological storage options for commercial development. This study establishes a net present value (NPV) evaluation framework for geological hydrogen storage that integrates the updated techno-economic analysis and market-based operations. The capital asset pricing model (CAPM) and the related finance theories are applied to determine the risk-adjusted discount rate in building the NPV evaluation framework. The NPV framework has been applied to two geological hydrogen storage projects a single-turn storage serving downstream transportation seasonal demand versus a multiturn storage as part of an integrated renewables-based hydrogen energy system providing peak electric load. From the NPV framework both projects have positive NPVs $46 560 632 and $12 457 546 respectively and International Rate of Return (IRR) values which are higher than the costs of capital. The NPV framework is also applied to the sensitivity analysis and shows that the hydrogen price spread between withdrawal and injection prices site development and well costs are the top three factors that impact both NPV and IRR the most for both projects. The established NPV framework can be used for project risk management by discovering the key cost drivers for the storage assets.
Linking Cost Decline and Demand Surge in the Hydrogen Market: A Case Study in China
Jun 2023
Publication
Hydrogen is crucial in achieving global energy transition and carbon neutrality goals. Existing market estimates typically presume linear or exponential growth but fail to consider how market demand responds to the declining cost of underlying technologies. To address this this study utilizes a learning curve model to project the cost of electrolyzers and its subsequent impact on hydrogen market aligning with a premise that the market demand is proportional to the cost of hydrogen. In a case study of China’s hydrogen market projecting from 2020 to 2060 we observed substantial differences in market evolution compared to exponential growth scenarios. Contrary to exponential growth scenarios China’s hydrogen market experiences faster growth during the 2020–2040 period rather than later. Such differences underscore the necessity for proactive strategic planning in emerging technology markets particularly for those experiencing rapid cost decline such as hydrogen. The framework can also be extended to other markets by using local data providing valuable insights to investors policymakers and developers engaged in the hydrogen market.
Optimal Design and Sizing of Hybrid Photovoltaic/Fuel Cell Electrical Power System
Aug 2023
Publication
Renewable energy solutions play a crucial role in addressing the growing energy demands while mitigating environmental concerns. This study examines the techno-economic viability and sensitivity of utilizing solar photovoltaic/polymer electrolyte membrane (PEM) fuel cells (FCs) to meet specific power demands in NEOM Saudi Arabia. The novelty of this study lies in its innovative approach to analyzing and optimizing PV/PEMFC systems aiming to highlight their economic feasibility and promote sustainable development in the region. The analysis focuses on determining the optimal size of the PV/PEMFC system based on two critical criteria: minimum cost of energy (COE) and minimum net present cost (NPC). The study considers PEMFCs with power ratings of 30 kW 40 kW and 50 kW along with four PV panel options: Jinko Solar Powerwave Tindo Karra and Trina Solar. The outcomes show that the 30 kW PEMFC and the 201 kW Trina Solar TSM-430NEG9R.28 are the most favorable choices for the case study. Under these optimal conditions the study reveals the lowest values for NPC at USD 703194 and COE at USD 0.498 per kilowatt-hour. The levelized cost of hydrogen falls within the range of USD 15.9 to 23.4 per kilogram. Furthermore replacing the 30 kW Trina solar panel with a 50 kW Tindo PV module results in a cost reduction of 32%. The findings emphasize the criticality of choosing optimal system configurations to attain favorable economic outcomes thereby facilitating the adoption and utilization of renewable energy sources in the region. In conclusion this study stands out for its pioneering and thorough analysis and optimization of PV/PEMFC systems providing valuable insights for sustainable energy planning in NEOM Saudi Arabia.
Effects of Surface Modification on a Proton Exchange Membrane for Improvements in Green Hydrogen Production
Oct 2023
Publication
Proton Exchange Membrane (PEM) electrolysis an advanced technique for producing hydrogen with efficiency and environmental friendliness signifies the forefront of progress in this domain. Compared to alkaline cells these electrolytic cells offer numerous advantages such as lower operating temperatures enhanced hydrogen production efficiency and eliminating the need for an aqueous solution. However PEM electrolysis still faces limitations due to the high cost of materials used for the membrane and catalysts resulting in elevated expenses for implementing large-scale systems. The pivotal factor in improving PEM electrolysis lies in the Platinum catalyst present on the membrane surface. Enhancing catalytic efficiency through various methods and advancements holds immense significance for the progress of this technology. This study investigates the use of patterned membranes to improve the performance of PEM electrolytic cells toward green hydrogen production. By increasing the Platinum loading across the membrane surface and enhancing catalytic performance these patterned membranes overcome challenges faced by conventionally fabricated counterparts. The findings of this research indicate that membranes with modified surfaces not only exhibit higher current draw but also achieve elevated rates of hydrogen production.
Hydrogen-Powered Aircraft at Airports: A Review of the Infrastructure Requirements and Planning Challenges
Nov 2023
Publication
Hydrogen-fueled aircraft are a promising innovation for a sustainable future in aviation. While hydrogen aircraft design has been widely studied research on airport requirements for new infrastructure associated with hydrogen-fueled aircraft and its integration with existing facilities is scarce. This study analyzes the current body of knowledge and identifies the planning challenges which need to be overcome to enable the operation of hydrogen flights at airports. An investigation of the preparation of seven major international airports for hydrogen-powered flights finds that although there is commitment airports are not currently prepared for hydrogen-based flights. Major adjustments are required across airport sites covering land use plans airside development utility infrastructure development and safety security and training. Developments are also required across the wider aviation industry including equipment updates such as for refueling and ground support and supportive policy and regulations for hydrogen-powered aircraft. The next 5–10 years is identified from the review as a critical time period for airports given that the first commercial hydrogen-powered flight is likely to depart in 2026 and that the next generation of short-range hydrogen-powered aircraft is predicted to enter service between 2030 and 2035.
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