LHX2

An overview of the hydrogen value chain. Photo Credit, all images: IDTechEx While much focus in the rapidly growing hydrogen sector has been placed on the upstream development of low-carbon hydrogen production sites and downstream advancements in fuel cell technologies and industrial use cases, the midstream infrastructure needed to store and transport hydrogen has often received less consideration. A new market report released by research and consultancy firm IDTechEx (Cambridge, U.K.) titled “Hydrogen Economy 2023-2033: Production, Storage, Distribution & Applications,” delves deeper into the subject of hydrogen storage and distribution technologies, a critical link to bridge the gap between hydrogen production and consumption. Despite its impressive gravimetric energy density, one of the main challenges with hydrogen cited by IDTechEx is the complexity of its storage and transportation. This stems from its extremely low density at ambient conditions leading to low volumetric energy density. Consequently, significant compression (100 to 700 bar) or liquefaction at an extreme boiling point of -253°C is necessary to enhance its volumetric energy density for storing and transporting adequate amounts. Hydrogen developments demonstrating liquid hydrogen (LH2) tanks: Although mature, incumbent compressed gas and cryogenic liquid storage methods have significant disadvantages. These methods are energy-intensive, diminishing the hydrogen's net energy content. Compression consumes 10-30% of the original energy, while liquefaction can use up to 30-40%, with the added burden of requiring a separate liquefaction plant, entailing considerable capital investment. Such inefficiencies hinder some applications, such as fuel cell electric vehicle (FCEV) mobility and energy storage, by sharply lowering the overall energy efficiency. Safety risks with compressed gas storage and boil-off issues with liquid H2 storage lead to hydrogen loss, further exacerbating the challenges (read about how Cryomotive’s cryo-compressed hydrogen solution claims the highest storage density, lowest refueling cost and widest operating range without H2 losses). Collectively, these factors make domestic and international transport of hydrogen expensive and inefficient. Globally, hydrogen pipelines do exist, totaling an estimated 5,000 kilometers, but their reach is largely restricted to specific regions like parts of Texas and Louisiana around the Gulf Coast or areas in France, Belgium, Netherlands and Germany. Typically operated by industrial gas giants like Air Products, Linde and Air Liquide, these pipelines serve industrial facilities such as refineries within a limited range of production sites. This confinement emphasizes the pressing need to expand pipeline networks to connect varying regions of production and consumption more widely. Hydrogen storage options, use cases Many solutions are available, but the optimal choice depends on storage size and application. Compressed gas and LH2 storage tanks will likely continue to serve stationary storage applications, such as hydrogen refueling stations. Liquid hydrogen spheres may be used to store large quantities at production sites and import/export terminals. Established players like Tenaris (compressed gas storage), Chart Industries (LH2 tanks) and McDermott CB&I (LH2 spherical vessels) already supply these well-commercialized solutions. Compressed hydrogen tanks, especially Type III and IV composite tanks, are gaining traction in the FCEV market, as they are most suitable to store hydrogen on-board of a vehicle. Many FCEVs, such as the Hyundai Nexo and Toyota Mirai, use Type IV tanks storing hydrogen at 700 bar. Compressed storage is expected to persist in many FCEV segments, dominating light-duty ones. However, LH2 tanks present the advantage of higher capacities, which could be beneficial for the heavy-duty segments. Hence, some companies, like Daimler Truck, are trialing the use of LH2. Storage systems using metal hydrides show promise for stationary applications similar to existing compressed and LH2 systems. These systems, which operate at much lower pressures (10-50 bar) and use pressure cycling for adsorption/release, may be more suitable for hydrogen energy storage applications due to reduced energy consumption and, thus, improved round-trip efficiency. Companies like GKN Hydrogen are progressing towards commercialization, having demonstrated its systems in off-grid energy storage and residential combined heat and power. Many more companies are developing systems based on metal hydrides. Underground hydrogen storage, using reservoirs like salt caverns, builds on established natural gas storage methods. Integration of such facilities into hydrogen pipeline networks is planned by operators like Uniper and Gasunie in the coming years. Underground storage is expected to play a key role in seasonal hydrogen storage to supply sectors in times of lower demand, like natural gas storage. Underground facilities may also be used by industrial projects as a buffer reserve of hydrogen — HYBRIT, a sustainable steelmaking project in Sweden, is testing such a concept using a lined rock cavern (LRC). However, regulation and long project development times remain key challenges for this storage type. For a deeper look into hydrogen storage solution developments, take a look at: Hydrogen distribution options, use cases Currently, compressed and LH2 trailers supply smaller scale applications like refueling stations or pilot projects. IDTechEx reports that this trend is likely to continue as large-scale transportation where continuous hydrogen supplies are needed may not be viable with these methods. Many types of vessels could be used in terms of compressed gas transport, from Type I to IV, developed by companies like Hexagon Purus (read “Hexagon Purus Westminster: Experience, growth, new developments in hydrogen storage”). Other companies, such as Lifte H2, are using trailer concepts to develop mobile refuelers, which can compensate for the lack of a hydrogen refueling station. Hydrogen storage and distribution methods. Large-scale and longer distance transport will necessitate pipelines, either running directly from production to end-use sites or feeding into pipeline networks. New construction is planned, with some projects like the HyNet North West Hydrogen Pipeline already underway. Repurposing natural gas pipelines is a possibility but requires extensive simulation, testing and risk evaluation to identify suitable pipelines. For example, the European Hydrogen Backbone initiative is developing a large-scale pipeline network, with more than 30 operators participating; many of the pipelines that will be used are planned to be repurposed from existing networks. Blending hydrogen into natural gas is also a popular topic as it is a way of partially decarbonizing the heating and power sector, with projects like HyDeploy proving a blend of 20 vol% being safe in existing pipelines. However, a higher percentage of hydrogen blends will require the modification of many appliances and equipment in the residential and industrial sectors. International long-distance transport may involve LH2 or conversion to hydrogen carriers like ammonia or liquid organic hydrogen carriers (LOHC). LH2 transport was demonstrated by the Suiso Frontier vessel (built by Kawasaki Heavy Industries) in the HESC project, transporting hydrogen from Australia to Japan. However, this pathway may be less viable compared to carriers due to the technical and commercial difficulties of dealing with LH2. Future insights The global embrace of hydrogen storage and distribution technologies will expand as production and end-use sites increase. This represents an opportunity for product supply, project development and R&D to innovate and refine existing methods. IDTechEx projects the global low-carbon hydrogen production market to reach $130 billion by 2033, expecting substantial growth in transport and storage solutions. Its new report offers an exhaustive overview of the value chain, including technological analyses, comparisons, commercial activities, innovations and market trends.

Researchers report that neuronal activity is necessary and sufficient for astrocytes to develop their complex shape, and interrupting this developmental process results in disrupted brain function. Researchers at Baylor College of Medicine have unraveled the processes that give astrocytes, the most abundant glial cell in the brain, their special bushy shape, which is fundamental for brain function. They report in the journal Nature that neuronal activity is necessary and sufficient for astrocytes to develop their complex shape, and interrupting this developmental process results in disrupted brain function. "Astrocytes play diverse roles that are vital for proper brain function," said first author Yi-Ting Cheng, a graduate student in Dr. Benjamin Deneen's lab at Baylor. "For instance, they support the activity of other essential brain cells, neurons; participate in the formation and function of synapses, or neuron-to-neuron connections; release neurotransmitters, chemicals that mediate neuronal communication; and make the blood-brain barrier." In the adult brain, the bushy shape of astrocytes is fundamentally linked to effective brain function. The ends of the branched-out astrocyte structure interact with neurons and regulate synaptic activity. "If astrocytes lose their structure, then synapses do not behave properly and brain function goes awry," said Deneen, professor and Dr. Russell J. and Marian K. Blattner Chair in the Department of Neurosurgery and director of the Center for Cancer Neuroscience at Baylor. He also is the corresponding author of the work. "Figuring out how astrocytes acquire their complex, bushy structure is essential to understanding how the brain develops and functions and may bring new insight into how neurodevelopmental conditions emerge. In this study, we investigated the cells and processes that direct the development of astrocyte structure." Neurons lead the way When astrocytes develop, neurons are already present and active, so do neurons influence how astrocytes acquire their complex shape? "We artificially activated or silenced neurons and determined whether this would speed up or slow down astrocyte maturation," Cheng said. "We found that neuronal activity is both necessary and sufficient to drive full astrocyte maturation into a bushy-shaped cell." So how are astrocytes receiving the signals that direct them down to the proper maturation path? Through several experimental approaches the team discovered that neurons produce a neurotransmitter called GABA that binds to astrocytes via a molecule on their surface named GABAB receptor. "We knocked out the GABAB receptor in astrocytes and activated the neurons. In this situation, the neurons did not promote the development of a typical astrocyte shape, supporting the idea that neurons communicate with astrocytes via the GABAB receptor to promote their maturation." "This finding was surprising and very interesting," Deneen said. "Neurotransmitters such as GABA are known to signal between neurons at synapses, but we discovered that neurotransmitters also signal astrocytes, influencing their development by triggering changes in their structure." Other experiments revealed more pieces of the puzzle of how neurons lead astrocytes to develop their bushy shape. "Neurons produce GABA, which binds to astrocytes via the GABAB receptor. In turn, this activates a series of events, including triggering the expression of another receptor called Ednrb, which drives pathways that remodel cellular architecture inside the cells associated with cell shape," Cheng said. The researchers also investigated another mystery related to astrocyte development. They found that regulation of the expression of GABAB receptor in astrocytes does not occur in the same way in different brain regions. "This result was totally unexpected," Deneen said. "The GABAB receptor is universally required for astrocytes to develop their bushy shape in all brain regions. How is it regulated differently in different areas of the brain?" Through bioinformatics analyses the researchers discovered that this regional regulation is conferred by two proteins, LHX2 in the brain cortex and NPAS3 in the olfactory bulb through their region-specific interactions with proteins SOX9 and NFIA, which are present in all astrocytes where they regulate GABAB receptor expression. In the cortex, LHX2 only binds to NFIA, while in the olfactory bulb NPS3 only binds to SOX9, enabling each one to regulate GABAB receptor expression in a specific brain region. Altogether, the findings suggest that astrocyte development and function involve a complex pattern of events and proteins triggered by the activity of neurons and that operate in a region-specific manner. Estefania Luna-Figueroa, Junsung Woo, Hsiao-Chi Chen, Zhung-Fu Lee1 and Akdes Serin Harmanci, all at Baylor College of Medicine, also contributed to this work. This work was supported by National Institutes of Health (NIH) grants NS071153, AG071687 and NS096096, the David and Eula Wintermann Foundation, NIH shared instrument grants S10OD023469, S10OD025240 and P30EY002520, the Cytometry and Cell Sorting Core at Baylor College of Medicine with funding from the CPRIT Core Facility Support Award (CPRIT-RP180672), the NIH (CA125123 and RR024574) and the NIH Eunice Kennedy Shriver National Institute of Child Health & Human Development under Award Number P50HD103555.

Collins Aerospace will lead the COCOLIH2T consortium for the Clean Hydrogen Partnership topic: “Development of specific aviation cryogenic storage system with a gauging, fuel metering, heat management and monitoring system,” Photo Credit: Collins Aerospace Collins Aerospace (Charlotte, N.C., U.S.), through its subsidiaries in Europe, has been selected to lead the COCOLIH2T (Composite Conformal Liquid H2 Tank) project by the European Commission’s Clean Hydrogen Partnership, a public-private partnership supporting research and innovation activities in hydrogen (H2) technologies in Europe. The Collins-led consortium will bring together Collins sites across France, Italy, the U.K., Poland, the Netherlands, Ireland and the U.S., to work with project partners NLR, Delft University of Technology, ATR, Novotech and Unified International. This consortium will work to develop new thermoplastic composites technology for liquid hydrogen (LH2) tanks to power H2 propulsion architectures in future more sustainable aircraft. Collins reports that while LH2 contains approximately three times as much energy per kilogram as traditional jet fuel, it has a lower specific density — LH2 requires nearly four times as much volume to match the energy content of the same mass of traditional jet fuel. Thermoplastic composite tank structures are in development to provide a strong, yet lightweight tank design to help overcome this challenge to using green H2 as a zero-emission aviation fuel. Novotech has significant expertise in thermoplastic composites for aircraft. Photo Credit: Novotech Aerospace Advanced Technology Multi-material, conformal tank for structural integration As described on the Clean Hydrogen Partnership page for COCOLIH2T, the three-year (Jan 2023-Jan 2026), €8.7 million project is proposing “a disruptive concept focused on reducing the impact of the tank’s weight and volume within an aircraft, while ensuring system safety. COCOLIH2T will not only develop a safe composite and vacuum insulated LH2 tank for the aviation sector but has the ambition to go beyond by designing and manufacturing a conformal tank through novel fabrication technologies enabling a reduction of more than 60% in production energy consumption and at least 50% in production time leading to significantly lower manufacturing costs. Additionally, the proposed structure of the tank, based on a multi-material thermoplastic composite concept, is intended to facilitate aircraft structural integration to support overall system weight reduction compared with conventional tank configurations. The key challenge that COCOLIH2T will tackle is the generation of a feasible and affordable design of a conformal variable section box-shape tank while minimizing the boil-off leakages wherever possible. COCOLIH2T’s overall system will be demonstrated at TRL4 by 2025.” Conformable composite tanks for compressed gas hydrogen (CGH2) at 700 bar are being developed by TU Munich and other partners (see “TU Munich develops cuboidal conformable tanks using carbon fiber composites …”). The COCOLIH2T consortium was awarded this project based on its response to the call for proposals issued by the Clean Hydrogen Partnership in 2022, specifically “Development of specific aviation cryogenic storage system with a gauging, fuel metering, heat management and monitoring system,” TOPIC ID: HORIZON-JTI-CLEANH2-2022-03-07. COCOLIH2T is funded by the European Union under Grant Agreement 101101404. As explained on the above-linked European Commission project page, expected outcomes for this topic include that two functional demonstrators capable of storing between 50 and 150 kilograms of LH2 will be built. The demonstrators will be used to validate the operation of such a storage system including design and integration of components needed for safe function including filling, structural health monitoring (SHM), overpressure, thermal management, boil-off, sloshing and vaporizing depending on a system safety analysis. The topic page goes on to describe how today’s LH2 tanks in aerospace “are mostly made of metal. For space applications this solution is still valid, because of power available, non-reuse and costs. But having in mind commercial aviation, the focus should be on enhancing the reliability of the metal tank and piping performance while designing a LH2 storage system made of light, carbon fiber-reinforced materials. Using these components, a significantly improved gravimetric index for the whole storage system can be achieved. The drawback of using these materials is that the laminate quality or laminate architecture are of particular importance for permeability [movement of small H2 molecules through the laminate]. Different test specimens, different semi-finished products made of glass and carbon, fibers with polymer or metal matrix, different additives, liners and architectures as well as protective coatings have to be considered. In addition, a selection of adhesives has to be made for use in cryogenic environments.” In addition, cites the topic requirements, “the pressure and temperature of the LH2 should be monitored to validate feed and fuel gauging functions under flight accelerations. The analysis of dynamic loads as a result of fuel sloshing should be addressed numerically and experimentally, as well as the pressure development in the tank due to the interaction of the sloshing hydrogen and the thermodynamic environment in the tank. The design solution should address the changing pressure by either active or passive means (e.g., active pressurization control or passive anti-sloshing devices), to ensure safe operation of the engine feed systems.” The gained experiences on the two storage demonstrators will be used in phase 2 projects (2026-2030) to obtain and define the certification regulation of commercial aviation LH2 storage systems. In these follow-on projects, larger tanks must be developed to become flightworthy. COCOLIH2T project results are expected to contribute to the following objectives of the Clean Hydrogen Partnership: Tank gravimetric efficiency [%weight]: 16% in 2024 and 35% in 2030 LH2 tank capacity: 50-150 kilograms LH2 Dormancy: > 24 hours Venting rate: < 2%/day Filling rate: 300-500 kilograms/hour Boil-off : < 2%/day after dormancy Maximum diameter: < 1 meter Minimum operating pressure: 1 bar (pump fed) – 3 bar (pressure fed) Maximum operating pressure: 3 bar (pump fed) – 8 bar (pressure fed) Insulation Vacuum: 1*10^-5 mbar As reported by revolution.aero news, Collins Aerospace reported in late 2022 that it was taking part in seven projects under the Clean Aviation Joint Undertaking. Collins estimates that the funding it receives from Clean Aviation combined with its own R&D will reach €85 million ($88.3 million). “The COCOLIH2T project addresses the challenges of shifting from traditional jet fuel to a fully sustainable, clean burning H2 fuel,” Mary Lombardo, vice president, Advanced Technologies at Collins Aerospace, says. “Compared with traditional fuel tanks, H2 tanks must reduce weight and enable containment of cryogenic fluid. COCOLIH2T is the kind of aerospace industry cross-collaboration Collins is focused on to reduce the environmental impact of aviation and lead us to a sustainable future.” Collins describes thermoplastic composites as advanced materials known for their durability and unique manufacturing characteristics (see more at CW’s thermoplastic composites page). Collins notes these materials are lightweight, suitable for extreme temperatures and have the capacity to be recycled. Collins Aerospace, a Raytheon Technologies Corp. business, is a leader in technologically advanced and intelligent solutions for the global aerospace and defense industry.