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Hydrogen Energy Reviews

A topical collection in Energies (ISSN 1996-1073). This collection belongs to the section "A5: Hydrogen Energy".

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Editor

Topical Collection Information

Dear Colleagues,

Hydrogen is a carbon-free secondary energy source (energy carrier) which is predicted to have significant role in the global future energy system. Adoption of hydrogen in the energy system leads to high energy security, excellent environmental impacts, and high energy efficiency. Hydrogen can be widely produced from various primary energy sources, including fossil fuels (natural gas, coal, and oil) and renewables (biomass, wind, solar, and geothermal). In addition, as a secondary energy source, hydrogen also can be mutually converted from other secondary energy sources, including electricity, heat, and others (including metal fuels). Various studies and developments have been intensively conducted, largely related to the production, storage, transportation, and utilization of hydrogen.

This Topical Collection is dedicated to provide comprehensive review related to hydrogen adoption in our energy system, including a broad range of production, storage, transportation, and utilization of hydrogen. The following review topics are welcomed, but not limited to:

  • Energy modeling and system;
  • Integration of hydrogen with other energy sources;
  • Hydrogen production system;
  • Hydrogen storage system (e.g. compressed, liquid, metal hydrides, chemical hydrides, adsorption);
  • Transportation system;
  • Hydrogen utilization system;
  • Hydrogen combustion (e.g. dedicated combustion, mix/blending, CFD, etc.);
  • Conversion processes (e.g. gasification, shift reaction, chemical looping, etc.);
  • Process design and optimization;
  • Ammonia and its production and utilization;
  • Liquefaction and regasification;
  • Hydrogenation and dehydrogenation;
  • Hydrogen-based power generation (including cycles for hydrogen combustion, fuel cell, etc.);
  • Catalysts for hydrogen production, storage, and utilization;
  • Fuel cell;
  • Economic analysis;
  • Environmental assessments;
  • Advanced materials, nano-technology and nano-materials;
  • Energy and exergy analysis.

Prof. Dr. Muhammad Aziz
Collection Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the collection website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Energies is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • hydrogen production
  • hydrogen storage
  • transportation
  • utilization
  • compression
  • ammonia
  • metal hydride
  • chemical hydride
  • adsorption
  • hydrogen liquefaction
  • compression
  • catalyst
  • gasification
  • chemical looping
  • shift reaction
  • fuel cell
  • integrated system
  • hydrogenation
  • dehydrogenation
  • hydrogen combustion
  • economic analysis
  • environmental assessment
  • energy modeling
  • process design
  • materials
  • energy-exergy analyses

Published Papers (13 papers)

2023

Jump to: 2022, 2021

74 pages, 9961 KiB  
Review
Hydrogen-Based Energy Systems: Current Technology Development Status, Opportunities and Challenges
by Inês Rolo, Vítor A. F. Costa and Francisco P. Brito
Energies 2024, 17(1), 180; https://doi.org/10.3390/en17010180 - 28 Dec 2023
Cited by 5 | Viewed by 2945
Abstract
The use of hydrogen as an energy carrier within the scope of the decarbonisation of the world’s energy production and utilisation is seen by many as an integral part of this endeavour. However, the discussion around hydrogen technologies often lacks some perspective on [...] Read more.
The use of hydrogen as an energy carrier within the scope of the decarbonisation of the world’s energy production and utilisation is seen by many as an integral part of this endeavour. However, the discussion around hydrogen technologies often lacks some perspective on the currently available technologies, their Technology Readiness Level (TRL), scope of application, and important performance parameters, such as energy density or conversion efficiency. This makes it difficult for the policy makers and investors to evaluate the technologies that are most promising. The present study aims to provide help in this respect by assessing the available technologies in which hydrogen is used as an energy carrier, including its main challenges, needs and opportunities in a scenario in which fossil fuels still dominate global energy sources but in which renewables are expected to assume a progressively vital role in the future. The production of green hydrogen using water electrolysis technologies is described in detail. Various methods of hydrogen storage are referred, including underground storage, physical storage, and material-based storage. Hydrogen transportation technologies are examined, taking into account different storage methods, volume requirements, and transportation distances. Lastly, an assessment of well-known technologies for harnessing energy from hydrogen is undertaken, including gas turbines, reciprocating internal combustion engines, and fuel cells. It seems that the many of the technologies assessed have already achieved a satisfactory degree of development, such as several solutions for high-pressure hydrogen storage, while others still require some maturation, such as the still limited life and/or excessive cost of the various fuel cell technologies, or the suitable operation of gas turbines and reciprocating internal combustion engines operating with hydrogen. Costs below 200 USD/kWproduced, lives above 50 kh, and conversion efficiencies approaching 80% are being aimed at green hydrogen production or electricity production from hydrogen fuel cells. Nonetheless, notable advances have been achieved in these technologies in recent years. For instance, electrolysis with solid oxide cells may now sometimes reach up to 85% efficiency although with a life still in the range of 20 kh. Conversely, proton exchange membrane fuel cells (PEMFCs) working as electrolysers are able to sometimes achieve a life in the range of 80 kh with efficiencies up to 68%. Regarding electricity production from hydrogen, the maximum efficiencies are slightly lower (72% and 55%, respectively). The combination of the energy losses due to hydrogen production, compression, storage and electricity production yields overall efficiencies that could be as low as 25%, although smart applications, such as those that can use available process or waste heat, could substantially improve the overall energy efficiency figures. Despite the challenges, the foreseeable future seems to hold significant potential for hydrogen as a clean energy carrier, as the demand for hydrogen continues to grow, particularly in transportation, building heating, and power generation, new business prospects emerge. However, this should be done with careful regard to the fact that many of these technologies still need to increase their technological readiness level before they become viable options. For this, an emphasis needs to be put on research, innovation, and collaboration among industry, academia, and policymakers to unlock the full potential of hydrogen as an energy vector in the sustainable economy. Full article
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20 pages, 2160 KiB  
Review
Combined Methane Pyrolysis and Solid Carbon Gasification for Electrified CO2-Free Hydrogen and Syngas Production
by Patrice Perreault, Cristian-Renato Boruntea, Heena Dhawan Yadav, Iria Portela Soliño and Nithin B. Kummamuru
Energies 2023, 16(21), 7316; https://doi.org/10.3390/en16217316 - 28 Oct 2023
Cited by 1 | Viewed by 2257
Abstract
The coupling of methane pyrolysis with the gasification of a solid carbon byproduct provides CO2-free hydrogen and hydrogen-rich syngas, eliminating the conundrum of carbon utilization. Firstly, the various types of carbon that are known to result during the pyrolysis process and [...] Read more.
The coupling of methane pyrolysis with the gasification of a solid carbon byproduct provides CO2-free hydrogen and hydrogen-rich syngas, eliminating the conundrum of carbon utilization. Firstly, the various types of carbon that are known to result during the pyrolysis process and their dependencies on the reaction conditions for catalytic and noncatalytic systems are summarized. The synchronization of the reactions’ kinetics is considered to be of paramount importance for efficient performance. This translates to the necessity of finding suitable reaction conditions, carbon reactivities, and catalysts that might enable control over competing reactions through the manipulation of the reaction rates. As a consequence, the reaction kinetics of methane pyrolysis is then emphasized, followed by the particularities of carbon deposition and the kinetics of carbon gasification. Given the urgency in finding suitable solutions for decarbonizing the energy sector and the limited information on the gasification of pyrolytic carbon, more research is needed and encouraged in this area. In order to provide CO2-free hydrogen production, the reaction heat should also be provided without CO2. Electrification is one of the solutions, provided that low-carbon sources are used to generate the electricity. Power-to-heat, i.e., where electricity is used for heating, represents the first step for the chemical industry. Full article
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18 pages, 32426 KiB  
Review
Hydrogen as a Renewable Energy Carrier in a Hybrid Configuration of Distributed Energy Systems: Bibliometric Mapping of Current Knowledge and Strategies
by Przemysław Ogarek, Michał Wojtoń and Daniel Słyś
Energies 2023, 16(14), 5495; https://doi.org/10.3390/en16145495 - 20 Jul 2023
Cited by 6 | Viewed by 1430
Abstract
Storing energy in hydrogen deposits balances the operation of energy systems and is an effective tool in the process of energy transformation towards achieving Sustainable Development Goals. To assess the validity of its use as an alternative renewable energy carrier in dispersed energy [...] Read more.
Storing energy in hydrogen deposits balances the operation of energy systems and is an effective tool in the process of energy transformation towards achieving Sustainable Development Goals. To assess the validity of its use as an alternative renewable energy carrier in dispersed energy systems of hybrid configuration, a comprehensive review of scientific literature was conducted in this study, based on bibliometric analysis. The bibliographic database used in the study was the international Web of Science database. This review contributes to a better understanding of the characteristics of the selected research area. The evolution of research trends implemented in the design of energy systems associated with hydrogen technologies is revealed, clearly indicating that it is a developing field. In recent years, there has been an increase in the number of publications, although the territorial range of research (mainly simulation) conducted in the domain does not include areas with the most favourable infrastructural conditions. The analysis reveals weak cooperation between South American, African, East Asian, and Oceanic countries. In the light of earlier, thematically similar literature reviews, several research gaps are also identified and proposals for future research are presented. They concern, in particular, the parallel implementation and optimization of the operation of hydrogen (HRES—Hybrid Renewable Energy System and HESS—Hybrid Energy Storage System) solutions in terms of economics, ecology, lifespan, and work efficiency, as well as their feasibility analysis. With the support of other researchers and those involved in the subject matter, this review may contribute to the further development of hybrid hydrogen systems in terms of increasing competitiveness and promoting the implementation of these technologies. Full article
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16 pages, 891 KiB  
Review
Fault Detection for PEM Fuel Cells via Analytical Redundancy: A Critical Review and Prospects
by Mukhtar Sani, Maxime Piffard and Vincent Heiries
Energies 2023, 16(14), 5446; https://doi.org/10.3390/en16145446 - 18 Jul 2023
Cited by 2 | Viewed by 1050
Abstract
Decarbonization of the transport sector could be achieved through fuel cell technology. The candidature of this technology is motivated by its high current density and lack of emissions. However, its widespread deployment is restrained by durability and reliability constraints. During normal operation, the [...] Read more.
Decarbonization of the transport sector could be achieved through fuel cell technology. The candidature of this technology is motivated by its high current density and lack of emissions. However, its widespread deployment is restrained by durability and reliability constraints. During normal operation, the fuel cell system supplies stable power to the load. Contrarily, when it is operated under faulty conditions, the system’s output power deteriorates, leading to low durability. It is therefore of paramount importance to ensure that the system is operated in a non-faulty condition. In this paper, we provide a critical review of the analytical-redundancy-based fault diagnosis methods for proton exchange membrane fuel cells (PEMFCs). An in-depth analysis of the various methods has been presented in terms of accuracy, complexity, implementability, and robustness to aging and dynamic operating conditions. Full article
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24 pages, 1882 KiB  
Review
Metal-Supported Solid Oxide Fuel Cells: A Review of Recent Developments and Problems
by Serikzhan Opakhai and Kairat Kuterbekov
Energies 2023, 16(12), 4700; https://doi.org/10.3390/en16124700 - 14 Jun 2023
Cited by 7 | Viewed by 3095
Abstract
The design of metal-supported solid oxide fuel cells (MS-SOFCs) has again aroused interest in recent years due to their low cost of materials, strength, and resistance to thermal cycling, as well as the advantages of manufacturability. MS-SOFCs are promising electrochemical devices for hydrogen [...] Read more.
The design of metal-supported solid oxide fuel cells (MS-SOFCs) has again aroused interest in recent years due to their low cost of materials, strength, and resistance to thermal cycling, as well as the advantages of manufacturability. MS-SOFCs are promising electrochemical devices for hydrogen energy. Compared to SOFCs, where ceramic electrodes or electrolytes are used as a carrier base, they are of great interest due to their fast start-up capability, greater reliability, mechanical stability, and resistance to the thermal cycle. MS-SOFCs have many advantages over conventional ceramic-based SOFCs, with the selection of metal-based electrode materials (anode, cathode) and their degradation processes being some of the biggest challenges facing researchers. Therefore, this review reports on the state of the latest research on MS-SOFCs with various structures, discusses the corresponding electrode materials and their existing problems, and puts forward topical issues that need to be addressed in MS-SOFCs. Full article
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23 pages, 2772 KiB  
Review
Non-Catalytic Partial Oxidation of Hydrocarbon Gases to Syngas and Hydrogen: A Systematic Review
by Iren A. Makaryan, Eugene A. Salgansky, Vladimir S. Arutyunov and Igor V. Sedov
Energies 2023, 16(6), 2916; https://doi.org/10.3390/en16062916 - 22 Mar 2023
Cited by 10 | Viewed by 3580
Abstract
The review contains a comparative analysis of studies on the production of hydrogen and syngas based on the processes of partial oxidation of natural gas and other types of gas feedstock. The results presented in the literature show the high potential of non-catalytic [...] Read more.
The review contains a comparative analysis of studies on the production of hydrogen and syngas based on the processes of partial oxidation of natural gas and other types of gas feedstock. The results presented in the literature show the high potential of non-catalytic autothermal processes of partial oxidation of hydrocarbons for the development of gas chemistry and energetics. The partial oxidation of hydrocarbons makes it possible to overcome such serious shortcomings of traditional syngas production technologies as technological complexity and high energy and capital intensity. The features of non-catalytic partial oxidation of hydrocarbon gases, the obtained experimental results and the results of kinetic modeling of various options for the implementation of the process, which confirm the adequacy of the kinetic mechanisms used for the analysis, are considered in detail. Examples of industrial implementation of processes based on partial oxidation and proposed alternative options for its organization are considered. Designs of reactors used to ensure stable conversion of rich mixtures of hydrocarbons with an oxidizer are presented. The possibility of obtaining other chemical products by partial oxidation of hydrocarbons is discussed. Full article
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42 pages, 3512 KiB  
Review
Semi-Systematic Literature Review on the Contribution of Hydrogen to Universal Access to Energy in the Rationale of Sustainable Development Goal Target 7.1
by Nikolas Schöne and Boris Heinz
Energies 2023, 16(4), 1658; https://doi.org/10.3390/en16041658 - 07 Feb 2023
Cited by 2 | Viewed by 1961
Abstract
As part of the United Nations’ (UN) Sustainable Development Goal 7 (SDG7), SDG target 7.1 recognizes universal electrification and the provision of clean cooking fuel as two fundamental challenges for global society. Faltering progress toward SDG target 7.1 calls for innovative technologies to [...] Read more.
As part of the United Nations’ (UN) Sustainable Development Goal 7 (SDG7), SDG target 7.1 recognizes universal electrification and the provision of clean cooking fuel as two fundamental challenges for global society. Faltering progress toward SDG target 7.1 calls for innovative technologies to stimulate advancements. Hydrogen has been proposed as a versatile energy carrier to be applied in both pillars of SDG target 7.1: electrification and clean cooking. This paper conducts a semi-systematic literature review to provide the status quo of research on the application of hydrogen in the rationale of SDG 7.1, covering the technical integration pathways, as well as the key economic, environmental, and social aspects of its use. We identify decisive factors for the future development of hydrogen use in the rationale of SDG target 7.1 and, by complementing our analysis with insights from the related literature, propose future avenues of research. The literature on electrification proposes that hydrogen can serve as a backup power supply in rural off-grid communities. While common electrification efforts aim to supply appliances that use lower amounts of electricity, a hydrogen-based power supply can satisfy appliances with higher power demands including electric cook stoves, while simultaneously supporting clean cooking efforts. Alternatively, with the exclusive aim of stimulating clean cooking, hydrogen is proposed to be used as a clean cooking fuel via direct combustion in distribution and utilization infrastructures analogous to Liquid Petroleum Gas (LPG). While expected economic and technical developments are seen as likely to render hydrogen technologies economically competitive with conventional fossil fuels in the future, the potential of renewably produced hydrogen usage to reduce climate-change impacts and point-of-use emissions is already evident today. Social benefits are likely when meeting essential safety standards, as a hydrogen-based power supply offers service on a high tier that might overachieve SDG 7.1 ambitions, while hydrogen cooking via combustion fits into the existing social habits of LPG users. However, the literature lacks clear evidence on the social impact of hydrogen usage. Impact assessments of demonstration projects are required to fill this research gap. Full article
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2022

Jump to: 2023, 2021

7 pages, 540 KiB  
Perspective
Perspectives on Hydrogen
by Alberto Abánades
Energies 2023, 16(1), 437; https://doi.org/10.3390/en16010437 - 30 Dec 2022
Cited by 5 | Viewed by 1650
Abstract
Humankind has an urgent need to reduce carbon dioxide emissions. Such a challenge requires deep transformation of the current energy system in our society. Achieving this goal has given an unprecedented role to decarbonized energy vectors. Electricity is the most consolidated of such [...] Read more.
Humankind has an urgent need to reduce carbon dioxide emissions. Such a challenge requires deep transformation of the current energy system in our society. Achieving this goal has given an unprecedented role to decarbonized energy vectors. Electricity is the most consolidated of such vectors, and a molecular vector is in the agenda to contribute in the future to those end uses that are difficult to electrify. Additionally, energy storage is a critical issue for both energy vectors. In this communication, discussion on the status, hopes and perspectives of the hydrogen contribution to decarbonization are presented, emphasizing bottlenecks in key aspects, such as education, reskilling and storage capacity, and some concerns about the development of a flexible portfolio of technologies that could affect the contribution and impact of the whole hydrogen value chain in society. This communication would serve to the debate and boost discussion about the topic. Full article
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21 pages, 4658 KiB  
Review
Main Trends and Research Directions in Hydrogen Generation Using Low Temperature Electrolysis: A Systematic Literature Review
by Cristina Hora, Florin Ciprian Dan, Nicolae Rancov, Gabriela Elena Badea and Calin Secui
Energies 2022, 15(16), 6076; https://doi.org/10.3390/en15166076 - 22 Aug 2022
Cited by 8 | Viewed by 2141
Abstract
Hydrogen (H2) is the most abundant element in the universe and it is also a neutral energy carrier, meaning the environmental effects of using it are strictly related to the effects of creating the means of producing of that amount of [...] Read more.
Hydrogen (H2) is the most abundant element in the universe and it is also a neutral energy carrier, meaning the environmental effects of using it are strictly related to the effects of creating the means of producing of that amount of Hydrogen. So far, the H2 generation by water electrolysis research field did not manage to break the efficiency barrier in order to consider H2 production as a technology that sustains financially its self-development. However, given the complexity of this technology and the overall environmental impacts, an up-to-date research and development status review is critical. Thus, this study aims to identify the main trends, achievements and research directions of the H2 generation using pure and alkaline water electrolysis, providing a review of the state of the art in the specific literature. Methods: In order to deliver this, a Systematic Literature Review was carried out, using PRISMA methodology, highlighting the research trends and results in peer review publish articles over more than two years (2020–2022). Findings: This review identifies niches and actual status of the H2 generation by water and alkaline water electrolysis and points out, in numbers, the boundaries of the 2020–2022 timeline research. Full article
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24 pages, 4015 KiB  
Review
A Comprehensive Review on Two-Step Thermochemical Water Splitting for Hydrogen Production in a Redox Cycle
by Daphne Oudejans, Michele Offidani, Achilleas Constantinou, Stefania Albonetti, Nikolaos Dimitratos and Atul Bansode
Energies 2022, 15(9), 3044; https://doi.org/10.3390/en15093044 - 21 Apr 2022
Cited by 12 | Viewed by 3526
Abstract
The interest in and need for carbon-free fuels that do not rely on fossil fuels are constantly growing from both environmental and energetic perspectives. Green hydrogen production is at the core of the transition away from conventional fuels. Along with popularly investigated pathways [...] Read more.
The interest in and need for carbon-free fuels that do not rely on fossil fuels are constantly growing from both environmental and energetic perspectives. Green hydrogen production is at the core of the transition away from conventional fuels. Along with popularly investigated pathways for hydrogen production, thermochemical water splitting using redox materials is an interesting option for utilizing thermal energy, as this approach makes use of temperature looping over the material to produce hydrogen from water. Herein, two-step thermochemical water splitting processes are discussed and the key aspects are analyzed using the most relevant information present in the literature. Redox materials and their compositions, which have been proven to be efficient for this reaction, are reported. Attention is focused on non-volatile redox oxides, as the quenching step required for volatile redox materials is unnecessary. Reactors that could be used to conduct the reduction and oxidation reaction are discussed. The most promising materials are compared to each other using a multi-criteria analysis, providing a direction for future research. As evident, ferrite supported on yttrium-stabilized zirconia, ceria doped with zirconia or samarium and ferrite doped with nickel as the core and an yttrium (III) oxide shell are promising choices. Isothermal cycling and lowering of the reduction temperature are outlined as future directions towards increasing hydrogen yields and improving the cyclability. Full article
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27 pages, 3474 KiB  
Review
A Comprehensive Review on the Prospects of Using Hydrogen–Methane Blends: Challenges and Opportunities
by Iren A. Makaryan, Igor V. Sedov, Eugene A. Salgansky, Artem V. Arutyunov and Vladimir S. Arutyunov
Energies 2022, 15(6), 2265; https://doi.org/10.3390/en15062265 - 20 Mar 2022
Cited by 33 | Viewed by 4354
Abstract
An analysis of the literature data indicates a wide front of research and development in the field of the use of methane–hydrogen mixtures as a promising environmentally friendly low-carbon fuel. The conclusion of most works shows that the use of methane–hydrogen mixtures in [...] Read more.
An analysis of the literature data indicates a wide front of research and development in the field of the use of methane–hydrogen mixtures as a promising environmentally friendly low-carbon fuel. The conclusion of most works shows that the use of methane–hydrogen mixtures in internal combustion engines improves their performance and emission characteristics. The most important aspect is the concentration of hydrogen in the fuel mixture, which affects the combustion process of the fuel and determines the optimal operating conditions of the engine. When using methane–hydrogen mixtures with low hydrogen content, the safety measures and risks are similar to those that exist when working with natural gas. Serious logistical problems are associated with the difficulties of using the existing gas distribution infrastructure for transporting methane–hydrogen mixtures. It is possible that, despite the need for huge investments, it will be necessary to create a new infrastructure for the production, storage and transportation of hydrogen and its mixtures with natural gas. Further research is needed on the compatibility of pipeline materials with hydrogen and methane–hydrogen mixtures, safety conditions for the operation of equipment operating with hydrogen or methane–hydrogen mixtures, as well as the economic and environmental feasibility of using these energy carriers. Full article
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2021

Jump to: 2023, 2022

29 pages, 2322 KiB  
Review
Liquid Hydrogen: A Review on Liquefaction, Storage, Transportation, and Safety
by Muhammad Aziz
Energies 2021, 14(18), 5917; https://doi.org/10.3390/en14185917 - 17 Sep 2021
Cited by 181 | Viewed by 24037
Abstract
Decarbonization plays an important role in future energy systems for reducing greenhouse gas emissions and establishing a zero-carbon society. Hydrogen is believed to be a promising secondary energy source (energy carrier) that can be converted, stored, and utilized efficiently, leading to a broad [...] Read more.
Decarbonization plays an important role in future energy systems for reducing greenhouse gas emissions and establishing a zero-carbon society. Hydrogen is believed to be a promising secondary energy source (energy carrier) that can be converted, stored, and utilized efficiently, leading to a broad range of possibilities for future applications. Moreover, hydrogen and electricity are mutually converted, creating high energy security and broad economic opportunities toward high energy resilience. Hydrogen can be stored in various forms, including compressed gas, liquid hydrogen, hydrides, adsorbed hydrogen, and reformed fuels. Among these, liquid hydrogen has advantages, including high gravimetric and volumetric hydrogen densities and hydrogen purity. However, liquid hydrogen is garnering increasing attention owing to the demand for long storage periods, long transportation distances, and economic performance. This paper reviews the characteristics of liquid hydrogen, liquefaction technology, storage and transportation methods, and safety standards to handle liquid hydrogen. The main challenges in utilizing liquid hydrogen are its extremely low temperature and ortho- to para-hydrogen conversion. These two characteristics have led to the urgent development of hydrogen liquefaction, storage, and transportation. In addition, safety standards for handling liquid hydrogen must be updated regularly, especially to facilitate massive and large-scale hydrogen liquefaction, storage, and transportation. Full article
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20 pages, 2948 KiB  
Review
The Future Is Colorful—An Analysis of the CO2 Bow Wave and Why Green Hydrogen Cannot Do It Alone
by Andreas von Döllen, YoungSeok Hwang and Stephan Schlüter
Energies 2021, 14(18), 5720; https://doi.org/10.3390/en14185720 - 10 Sep 2021
Cited by 6 | Viewed by 2577
Abstract
In both the private and public sectors, green hydrogen is treated as a promising alternative to fossil energy commodities. However, building up production capacities involves significant carbon production, especially when considering secondary infrastructure, e.g., renewable power sources. The amount of required capacity as [...] Read more.
In both the private and public sectors, green hydrogen is treated as a promising alternative to fossil energy commodities. However, building up production capacities involves significant carbon production, especially when considering secondary infrastructure, e.g., renewable power sources. The amount of required capacity as well as the carbon production involved is calculated in this article. Using Germany as an example we show that the switch to purely green hydrogen involves significant bow waves in terms of carbon production as well as financial and resource demand. An economic model for an optimal decision is derived and—based on empirical estimates—calibrated. It shows that, even if green hydrogen is a competitive technology in the future, using alternatives like turquoise hydrogen or carbon capture and storage is necessary to significantly reduce or even avoid the mentioned bow waves. Full article
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