Hydrogen Technologies: Recent Advances, New Perspectives, and Applications

Abstract

Hydrogen has become a crucial element in the search for clean energy solutions. It provides promise as a versatile and sustainable energy carrier. This chapter discusses the history of hydrogen technologies, tracing its journey from early industrial uses to its current pivotal role in modern energy systems. It explores the versatility and energy storage capabilities of hydrogen, emphasizing its potential for decarbonization in various sectors such as transport, industry, and electricity generation. The chapter aims to provide a comprehensive overview of recent advancements in hydrogen technologies, examining innovative production methods and groundbreaking applications. Through this exploration, it seeks to clarify the role of hydrogen in shaping global energy landscapes and contributing to sustainable practices. By assessing its impact across different sectors, the chapter highlights the significance of hydrogen in promoting a transition toward cleaner and more resilient energy systems that align with environmental goals and the pursuit of carbon neutrality.

1. Introduction

The energy sector finds itself at a pivotal juncture, marked by escalating demand and pressing global environmental concerns [1]. Hydrogen stands as a pivotal clean energy carrier in the modern energy landscape, offering a sustainable solution to global energy challenges. Its significance extends beyond being merely an energy source; it embodies a potential keystone for a low-carbon future. Historically, hydrogen technologies have evolved significantly, transitioning from early industrial uses to a cornerstone of contemporary clean energy systems.

Initially utilized in chemical processes and refining, hydrogen’s role has expanded due to its versatility, energy storage capabilities, and potential for decarbonization. Its ability to integrate with various energy sectors, including transport, industrial processes, and electricity, positions hydrogen as a crucial player in the transition toward sustainable energy practices. The historical context of hydrogen technologies reflects a journey of innovation and adaptation, underscoring its growing importance in achieving a balanced and resilient energy ecosystem that aligns with environmental goals and the pursuit of carbon neutrality [2].

In Europe, ambitious plans are underway to achieve climate neutrality by 2050, as outlined in the Paris Agreement [3]. Social imperatives underscore initiatives like the European Green Deal and its transformative “Fit for 55” package, aimed at driving decarbonization within the EU. Geopolitical dynamics further shape the energy landscape, evident in initiatives such as the “REPowerEU” plan, which seeks to swiftly reduce reliance on Russian fossil fuels [4].

Despite significant strides in renewable energy adoption, the intermittency of renewables poses a persistent challenge to their widespread integration into the energy mix. Addressing this hurdle, hydrogen (H₂) has emerged as a compelling solution for leveraging surplus electricity generated by sources like solar and wind parks, thereby enhancing the flexibility of energy systems [5]. Widely acknowledged as a key player in the green energy transition, hydrogen holds immense potential as an energy carrier with diverse applications across industries [6].

While currently utilized primarily in industrial processes and derived from fossil fuels, hydrogen is poised for a transformative expansion into sectors like transportation and construction in the coming decades, increasingly produced as a low-carbon fuel [7]. Countries worldwide have outlined roadmaps and national strategies for fostering the hydrogen economy, with deployment targets set for the next decade and beyond [8].

This transition heralds not just technological advancements but also significant cultural shifts, necessitating the development of robust market infrastructure and widespread accessibility to hydrogen resources. The evolution of the hydrogen economy is influenced by a myriad of factors, reflecting a diverse array of approaches across various disciplines [9]. In evaluating its sustainability, economic and environmental considerations often take center stage, comparing hydrogen technologies against conventional fossil fuels using metrics such as cost and carbon footprint.

However, it is crucial to recognize that prevailing global hydrogen energy models tend to prioritize techno-economic parameters, potentially diverging from societal preferences. Thus, while efficiency and cost-effectiveness remain vital, achieving a truly sustainable hydrogen economy demands a holistic approach that aligns with broader societal aspirations and values.

2. Recent advances in hydrogen production

This section delves into the latest advancements in hydrogen production, a critical pillar for the hydrogen economy’s viability and sustainability. It explores cutting-edge developments across various hydrogen production technologies, emphasizing innovations that enhance efficiency, reduce costs, and minimize environmental impacts. The focus is on breakthroughs in electrolysis, photoelectrochemical, and biological hydrogen production methods, each contributing uniquely to the diversification and resilience of clean hydrogen supply. By examining these recent advancements, the section aims to provide a thorough understanding of the current state-of-the-art technologies and their potential to revolutionize the hydrogen production landscape, paving the way for a sustainable energy future.

2.1 Electrolysis

Electrolysis, a principal method for hydrogen production, has undergone significant technological transformations, enhancing its appeal for large-scale, clean hydrogen generation. Recent years have seen remarkable progress in the development of advanced electrode materials and catalysts. These innovations have been pivotal in increasing the efficiency and durability of electrolyzers, particularly in proton exchange membrane (PEM) electrolysis (Figure 1). Enhanced catalysts offer reduced overpotentials, leading to lower energy consumption and increased operational efficiency. The advent of novel, earth-abundant catalysts also promises to reduce costs and reliance on scarce materials like platinum and iridium, making electrolysis more economically viable and sustainable.

Figure 1.

PEM electrolyzer cell [10].

Modern electrolysis systems are being designed with a focus on integration with renewable energy sources, such as solar and wind power. This integration is crucial for producing green hydrogen, ensuring that the hydrogen generation process is entirely carbon neutral. Innovations include adaptive systems that can operate efficiently under variable power inputs, enhancing the compatibility of electrolyzers with fluctuating renewable energy outputs, thereby optimizing the overall efficiency and cost-effectiveness of hydrogen production (Figure 2).

Figure 2.

Modern electrolysis systems [11].

High-temperature electrolysis (HTE) has gained attention for its potential to improve the overall system efficiency. By operating at elevated temperatures, HTE can utilize heat (often waste heat from industrial processes) to reduce the electrical energy required for hydrogen production. Recent advancements have focused on improving the durability and performance of high-temperature electrolyzers, developing robust solid oxide electrolyte materials that can withstand harsh operating conditions while maintaining high efficiency. High-temperature steam electrolysis, also known as steam electrolysis, is another promising method to produce hydrogen using the thermal energy produced by nuclear reactors. Unlike conventional water electrolysis, HTSE utilizes higher temperatures ranging from 800°C to 1000°C to split water molecules, thus requiring less electricity. This makes HTSE a more efficient and cost-effective method for hydrogen production [12].

The push toward commercializing electrolysis technology has led to significant advancements in scalability and the economic feasibility of large-scale operations. Efforts to scale up electrolyzer manufacturing, reduce capital costs, and improve system longevity are crucial for widespread adoption. The industry is moving toward gigawatt-scale production facilities, driven by decreasing costs and increasing demand for green hydrogen, especially in sectors like transportation, industry, and grid storage. These advancements collectively contribute to the ongoing evolution of electrolysis as a sustainable and economically feasible technology for hydrogen production, aligning with global energy transition goals and the growing emphasis on decarbonization.

2.2 Photoelectrochemical hydrogen production

Photoelectrochemical (PEC) hydrogen production represents a cutting-edge approach that directly converts solar energy into chemical energy, offering a promising pathway to sustainable hydrogen generation. PEC systems utilize semiconductor materials to absorb sunlight and generate electron-hole pairs, which then drive water-splitting reactions to produce hydrogen. The efficiency of these systems depends heavily on the semiconductor’s ability to absorb solar radiation, facilitate charge separation, and catalyze water reduction and oxidation reactions. Recent innovations focus on optimizing these materials for better light absorption, increased charge carrier mobility, and enhanced catalytic properties (Figure 3) [13].

Figure 3.

PEC system [13].

The core of the PEC technology lies in the development of efficient and stable semiconductor photocatalysts. Recent research has concentrated on novel materials like perovskites, quantum dots, and nanostructured semiconductors, which offer superior light absorption and charge separation efficiencies. Innovations in material engineering, such as doping, heterojunction formation, and surface passivation, have significantly enhanced the photocatalytic performance and stability under solar irradiation.

The design of PEC cells has evolved from traditional planar configurations to more advanced designs that maximize light absorption and minimize recombination losses. Concentrating PEC cells, tandem cell structures, and integrated PEC systems that combine photovoltaic cells with electrolyzers have emerged, showing enhanced solar-to-hydrogen conversion efficiencies. These innovative architectures are crucial for optimizing the spatial arrangement of materials and the overall integration of components within the PEC system.

Integrating PEC systems with existing renewable energy infrastructures offers a pathway to decentralized hydrogen production. Such integration enables the utilization of excess renewable energy to produce hydrogen, aligning hydrogen production with periods of high renewable availability. This synergy can enhance the overall efficiency of renewable energy systems, providing a storage solution in the form of hydrogen and facilitating a more resilient energy grid.

Despite significant progress, PEC hydrogen production faces challenges related to efficiency, durability, and scalability. Efficiency improvements are needed to make the technology economically competitive, while durability issues must be addressed to ensure long-term operation without significant degradation. Research is focused on developing protective coatings, advanced water-splitting catalysts, and engineered interfaces to overcome these challenges and improve the long-term stability of PEC cells.

The future of PEC hydrogen production is promising, with ongoing research aimed at overcoming current limitations and moving toward practical applications. The field is advancing toward the development of cost-effective, scalable, and efficient PEC systems capable of operating under real-world conditions. Collaborations between academia, industry, and government entities are vital in accelerating the translation of laboratory-scale innovations to commercial-scale applications, paving the way for PEC technology to contribute significantly to the global hydrogen economy. These insights reflect the dynamic nature of PEC hydrogen production research, highlighting the technological advancements and the potential of this method in contributing to a sustainable energy future.

2.3 Biological hydrogen production

Biological hydrogen production is an area of growing interest due to its potential for sustainable and eco-friendly fuel generation. This section outlines the significant advancements and insights in this field. Biological hydrogen production primarily involves two pathways: biophotolysis of water by algae and photofermentation by bacteria (Figure 4). These processes harness the natural ability of microorganisms to produce hydrogen from water or organic substrates, using sunlight or metabolic energy. Recent research has focused on enhancing these biological systems’ efficiency, scalability, and reliability, leveraging genetic engineering and biotechnological innovations.

Figure 4.

Biological hydrogen production methods.

Advances in genetic engineering have enabled the optimization of microbial strains for increased hydrogen yield and productivity. Scientists have manipulated the metabolic pathways of microorganisms like cyanobacteria and green algae to enhance their hydrogen-producing capabilities, focusing on the overexpression of hydrogenase enzymes and the suppression of competing metabolic processes that consume hydrogen. Biological hydrogen production is a challenging area in biotechnology, with environmental and energy source problems. However, in the past decade, hydrogen energy has made progress in all areas of energy. High potential exists in existing technologies for the development of practical H₂ production bioprocesses. Increasing rates of synthesis and final yields of H₂ require further research and development. Bioprocess integration, optimization of bioreactor design, rapid removal, purification of hydrogen, directed evolution of hydrogenase, and metabolic engineering of the H₂-evolving microorganism offer exciting prospects for biohydrogen systems. Novel strategies will also be very encouraging and exciting in the future. The rapid advances in biological and engineering sciences will facilitate overcoming existing bottlenecks and new challenges and create new opportunities for economical hydrogen production shortly [14].

The development of hybrid systems combining biotechnological and chemical processes represents a significant leap forward. These systems aim to optimize hydrogen production by integrating different biological and physicochemical stages, allowing for the sequential degradation of organic compounds and subsequent hydrogen generation, thereby increasing the overall process efficiency and yield. Innovations in bioreactor design have been crucial for scaling up biological hydrogen production. High-performance bioreactors with optimized conditions for microbial growth and hydrogen production have been developed, including photobioreactors for algae and fermenters for anaerobic bacteria. These systems are designed to maximize light penetration, nutrient supply, and waste removal, enhancing the efficiency and sustainability of hydrogen production.

Despite promising laboratory-scale results, scaling up biological hydrogen production to commercial levels poses significant challenges. These include maintaining stable microbial cultures over long periods, optimizing the production process for high-volume output, and ensuring economic viability. Ongoing research is addressing these challenges by developing robust microbial strains, efficient bioreactor systems, and integrated process technologies. The future of biological hydrogen production is promising, with the potential to contribute significantly to the renewable energy mix. The field is moving toward more sustainable and cost-effective solutions, focusing on utilizing waste biomass as a feedstock and integrating production systems with existing waste treatment facilities. This approach not only produces clean energy but also contributes to waste reduction and resource recovery, aligning with circular economy principles. The exploration of biological hydrogen production is a testament to the innovative approaches being pursued in the renewable energy sector, offering a glimpse into a future where clean fuel generation harmonizes with environmental stewardship.

3. Advances in hydrogen storage technologies

This section addresses the critical advancements in hydrogen storage technologies, a vital component for the widespread adoption of hydrogen as a clean energy carrier. It explores innovative solutions and recent breakthroughs that have significantly improved the efficiency, safety, and economic viability of hydrogen storage. From high-density solid-state systems to liquid organic carriers and advanced composite materials, this section will delve into the latest developments that are shaping the future of hydrogen storage, highlighting their potential to transform energy systems and facilitate a seamless transition to a hydrogen-based economy.

3.1 Solid-state hydrogen storage

Solid-state hydrogen storage is a key technology that offers high hydrogen density and the potential for safe, efficient energy storage, crucial for the widespread adoption of hydrogen as a clean energy carrier. Advances in materials science have led to the development of new solid-state hydrogen storage materials, such as complex metal hydrides, chemical hydrogen storage materials, and intermetallic compounds. These materials can absorb and release hydrogen through chemical reactions or physical processes, offering high storage densities and the potential for tailored thermodynamics and kinetics.

Researchers [15] have made significant strides in understanding and improving the hydrogen storage mechanisms of solid-state materials. This includes optimizing the absorption/desorption kinetics, increasing reversible hydrogen capacity, and reducing the operating temperatures required for efficient hydrogen release and uptake (Figure 5).

Figure 5.

Solid-state hydrogen storage mechanisms [15].

The integration of nanotechnology has been a game-changer in solid-state hydrogen storage, enabling the manipulation of materials at the atomic or molecular level to improve their hydrogen storage properties. Nanostructuring of storage materials can enhance surface area, modify reaction pathways, and improve kinetics, leading to faster charging and discharging rates and better overall performance. Innovations in system design and engineering have facilitated the development of more compact, efficient, and safer solid-state hydrogen storage systems. These systems are designed to optimize heat and mass transfer, accommodate the volumetric expansion of materials, and integrate seamlessly with fuel cell technologies and other hydrogen applications [16].

Despite progress, challenges remain in realizing the full potential of solid-state hydrogen storage, such as high activation energies, slow kinetics, and issues with scalability and cost. Ongoing research is focused on addressing these challenges through material modification, advanced engineering strategies, and the development of hybrid systems that combine the advantages of different storage methods. The future of solid-state hydrogen storage looks promising, with ongoing research pushing the boundaries of material performance and system integration. The aim is to achieve storage solutions that are not only efficient and safe but also economically viable for large-scale applications, paving the way for hydrogen to become a cornerstone of the global energy landscape. The advancements in solid-state hydrogen storage are pivotal for the transition to a hydrogen economy, offering solutions that could transform energy storage, transportation, and various industrial applications.

3.2 Liquid organic hydrogen carriers

Liquid organic hydrogen carriers (LOHCs) represent a transformative approach in hydrogen storage technologies, offering a safe, efficient, and energy-dense alternative to conventional storage methods. LOHCs are organic compounds capable of chemically binding and releasing hydrogen through hydrogenation and dehydrogenation reactions. They offer a practical solution for hydrogen storage and transportation, as they can operate at near-ambient conditions, making them safer and more adaptable to existing infrastructure compared to high-pressure or cryogenic hydrogen storage methods. The idea of storing hydrogen in LOHCs at room temperature is based on the process of hydrogenation and dehydrogenation of organic molecules (Figure 6). LOHCs are a type of hydrogen storage system that remains in a liquid state when it contains a high concentration of hydrogen. They are a potentially cost-effective, safe, and easily manageable way of storing hydrogen [17]. Additionally, LOHCs enable long-term energy storage without any losses or boil-off and can be transported easily. Key to the efficiency of LOHC systems is the development of advanced catalysts that facilitate rapid and reversible hydrogenation and dehydrogenation reactions.

Figure 6.

LOHC system [17].

Recent breakthroughs have focused on enhancing the activity, selectivity, and durability of these catalysts; reducing energy requirements; and improving the overall economic viability of the LOHC technology. Innovations in system design are crucial for optimizing the performance of LOHC systems. This includes the integration of advanced thermal management systems, improved reactor designs for enhanced kinetics, and scalable process configurations that can adapt to varying demands and operational conditions, ensuring efficient and consistent hydrogen release and storage [17]. The search for optimal LOHC materials has led to the exploration of various organic compounds, including aromatics, carbazoles, and heterocycles. These materials are evaluated based on their hydrogen storage capacity, stability, recyclability, and compatibility with existing infrastructure, driving the development of more effective and sustainable LOHC solutions.

Despite their potential, LOHC systems face challenges such as the need for high temperatures in dehydrogenation, the potential toxicity of certain carriers, and the long-term stability of the storage material. Research is directed toward overcoming these challenges by developing more efficient catalytic systems, identifying environmentally benign and cost-effective carriers, and enhancing the material’s recyclability and lifecycle. The future of the LOHC technology is promising, with ongoing research aimed at commercial-scale applications, integration with renewable energy sources, and development of mobile and stationary hydrogen storage solutions. The adaptability of LOHC systems to existing liquid fuel infrastructure presents a unique opportunity to facilitate the widespread adoption of hydrogen as a key energy carrier in the transition toward a sustainable energy economy. These detailed insights into LOHCs underscore their potential to revolutionize hydrogen storage, offering a viable pathway for the safe, efficient, and large-scale deployment of hydrogen energy solutions.

3.3 Advanced composite materials

Advanced composite materials for hydrogen storage are at the forefront of innovation, offering unique solutions that combine lightweight properties, high hydrogen storage capacities, and excellent safety profiles. The development of composite materials involves the integration of various substances, such as metal hydrides, polymers, and carbon-based materials, to create systems that can store hydrogen with high efficiency. These composites often leverage the synergistic properties of their constituents, offering enhanced hydrogen storage capacities, improved kinetics, and reduced risks of leakage [18].

Recent advances in materials science and research have enabled engineers to explore the use of less conventional materials in their designs. Composite materials are becoming increasingly popular in marine, aerospace, automotive, and other industries and offer excellent strength-to-weight ratios, improved thermal and mechanical properties, and other desirable qualities that result from combining different constituent materials. The use of composites in hydrogen storage tanks could improve the efficiency of such systems [18, 19, 20].

Looking forward, the emphasis on sustainability is driving the development of composite materials that are not only efficient and safe but also environmentally benign. The potential for recycling and reusability of these materials is an important consideration, aiming to ensure that the hydrogen economy is supported by circular economy principles. The exploration of advanced composite materials is crucial for overcoming the current limitations of hydrogen storage, offering promising prospects for the development of safe, efficient, and sustainable hydrogen energy systems.

4. New perspectives in hydrogen utilization

This section explores the evolving landscape of hydrogen utilization, highlighting innovative applications and the integration of hydrogen technologies into various sectors. It examines the latest trends and developments that are expanding the role of hydrogen beyond conventional uses, focusing on its potential in energy systems, industrial processes, and emerging markets. The discussion will encompass recent advancements in hydrogen fuel cells, combustion technologies, and the role of hydrogen in decarbonizing heavy industries, underscoring its significance in achieving a sustainable, low-carbon future.

4.1 Hydrogen fuel cells

Hydrogen fuel cells are a transformative technology in the energy sector, offering a clean, efficient alternative to conventional combustion-based power generation. Hydrogen fuel cells generate electricity through the electrochemical reaction of hydrogen and oxygen, producing water as the only byproduct. Recent advancements have focused on enhancing the efficiency, durability, and cost-effectiveness of these cells, broadening their applicability in energy systems. Significant strides have been made in developing advanced materials for electrodes, electrolytes, and catalysts, aiming to improve performance and reduce the costs of fuel cells. Innovations include the use of non-precious metal catalysts, durable polymer electrolytes, and improved electrode architectures that enhance the electrochemical surface area and catalytic activity.

Efforts in system integration involve optimizing fuel cell stacks for various scales and applications, from portable devices to large stationary installations. Scalability challenges are being addressed through modular design, allowing for the customization of power output to meet specific demands, and enhancing the versatility of fuel cell applications. The automotive industry has seen significant developments in hydrogen fuel cell vehicles (FCVs) (Figure 7), with improvements in fuel cell efficiency, vehicle range, and refueling infrastructure. These vehicles offer a sustainable alternative to traditional combustion engines, with the added benefits of quick refueling times and long driving ranges.

Figure 7.

Hydrogen fuel cell vehicles (FCVs) [21].

Beyond transportation, hydrogen fuel cells are gaining traction in stationary applications for backup power, grid support, and distributed energy systems, as well as in portable applications for consumer electronics, remote power, and emergency systems, showcasing their flexibility and adaptability across energy domains. While hydrogen fuel cells present a promising path toward decarbonization, challenges remain in terms of large-scale hydrogen production, infrastructure development, and market acceptance. Future research and development are geared toward addressing these challenges, with a focus on improving the economic viability and environmental impact of fuel cell technologies. The advancements in hydrogen fuel cells are pivotal for the transition to a cleaner energy landscape, offering innovative solutions for transportation, stationary power, and beyond, marking a significant step toward a sustainable, low-carbon future.

4.2 Hydrogen combustion

Hydrogen combustion is emerging as a pivotal technology in the transition to a cleaner energy future, offering new perspectives and applications. Hydrogen combustion is characterized by its high energy yield and clean emission profile, primarily producing water vapor when burned. The efficiency of hydrogen combustion engines is continually enhanced through innovations in combustion chamber design, fuel injection systems, and ignition timing optimization, aiming to maximize the energy output while minimizing any NOx emissions. Recent developments have focused on refining the combustion process to ensure complete hydrogen burn, reduce emissions, and improve overall system efficiency. Advancements in turbocharging, exhaust gas recirculation, and lean-burn technologies have been crucial in enhancing the performance and environmental compatibility of hydrogen combustion engines [22].

Hydrogen combustion is increasingly integrated with renewable energy sources. It serves as a flexible load for power systems, capable of storing excess renewable energy and releasing it when demand peaks. This integration facilitates a more resilient and sustainable energy infrastructure, leveraging hydrogen’s potential to balance and store renewable energy. Beyond its role in power generation, hydrogen combustion is gaining traction in industrial applications, including high-temperature processes in steelmaking, glass production, and other manufacturing sectors. It offers a pathway to decarbonize industrial heat processes, significantly reducing the carbon footprint associated with these industries [23].

Despite its potential, challenges remain in the widespread adoption of hydrogen combustion, such as ensuring safety, improving public perception, and developing infrastructure. Innovations in safety technologies, public engagement strategies, and the expansion of hydrogen refueling infrastructure are critical to overcoming these barriers. The future of hydrogen combustion looks promising, with ongoing research aimed at enhancing efficiency, reducing costs, and expanding applications. As the technology matures and scales up, hydrogen combustion is set to play a crucial role in a diverse range of sectors, from transportation to industrial heating, contributing significantly to global decarbonization efforts. Hydrogen combustion stands as a transformative technology, poised to significantly impact how energy is produced and utilized, driving forward the clean energy transition with its high efficiency and potential for broad application.

4.3 Hydrogen in chemical synthesis

The integration of hydrogen into chemical synthesis signifies a transformative shift toward greener chemical processes, leveraging hydrogen’s potential as a clean and sustainable reactant. Hydrogen is pivotal in developing eco-friendly synthesis routes, offering a cleaner alternative to traditional processes that rely on fossil fuels. Its application in chemical synthesis reduces carbon emissions, aligning with global sustainability goals and the increasing demand for green chemistry. This section elaborates on the multifaceted role of hydrogen in chemical synthesis [24].

Innovations in catalysis have revolutionized hydrogen’s role in chemical synthesis, enabling more efficient, selective, and lower-energy processes. Catalytic systems that facilitate hydrogenation reactions have become more robust, versatile, and capable of driving reactions under milder conditions, thus enhancing their industrial applicability and environmental compatibility. In the realm of organic and inorganic synthesis, hydrogen is employed as a powerful reducing agent. Its ability to facilitate the reduction of various functional groups while maintaining a clean environmental profile is paramount in synthesizing a wide array of chemicals, pharmaceuticals, and materials. Leveraging hydrogen in chemical synthesis has led to process intensification, where reactions can be conducted more rapidly, efficiently, and at lower temperatures. This not only improves the economics of chemical production but also significantly reduces the energy footprint, contributing to more sustainable industrial practices [25].

The synthesis of green chemicals using hydrogen can be further enhanced by integrating the processes with renewable energy sources. Electrochemical hydrogen generation from water, powered by solar or wind energy, provides a sustainable pathway for producing hydrogen that can be directly utilized in chemical manufacturing, closing the loop on a truly green process [26].

The integration of hydrogen into chemical synthesis holds the promise of revolutionizing the chemical industry, making it cleaner and more sustainable. However, challenges such as the development of cost-effective, efficient, and durable systems for hydrogen production and utilization, as well as the adaptation of industrial infrastructure, need to be addressed to fully realize this potential. The utilization of hydrogen in chemical synthesis not only stands as a testament to the versatility and sustainability of hydrogen but also opens new avenues for the development of green manufacturing processes, marking a significant step toward a sustainable chemical industry.

5. Emerging applications of hydrogen technologies

This section delves into the groundbreaking applications of hydrogen technologies that are shaping the future of energy, industry, and transportation. It explores innovative uses that extend beyond conventional boundaries, highlighting how hydrogen is being integrated into new markets and sectors. From powering zero-emission vehicles to enabling large-scale renewable energy storage and supporting decarbonization in various industries, this exploration sheds light on the versatility of hydrogen and its potential to drive significant environmental and economic benefits.

5.1 Hydrogen in transportation

Hydrogen is increasingly recognized as a pivotal energy carrier in the transportation sector, offering a sustainable alternative to fossil fuels. Hydrogen fuel cells are a key technology in powering zero-emission vehicles, particularly in the automotive industry. They convert hydrogen into electricity, generating only water vapor and heat as byproducts, thus providing a clean alternative to internal combustion engines. Recent advancements in fuel cell technology have enhanced efficiency, reduced costs, and extended the lifespan of these systems. These improvements are crucial for the commercial viability of hydrogen-powered vehicles, including cars, busses, and trucks.

The expansion of hydrogen refueling infrastructure is critical to the adoption of hydrogen in transportation. Efforts are underway globally to increase the number of hydrogen refueling stations, which is vital for supporting the widespread use of fuel cell vehicles. Hydrogen is particularly suited for heavy-duty and long-range transport applications, such as trucks, busses, and maritime vessels, where battery-electric solutions face challenges due to weight and range limitations.

Hydrogen transportation can be integrated with renewable energy sources, providing a pathway to reduce greenhouse gas emissions significantly. Using green hydrogen, produced from water electrolysis powered by renewables, enhances the environmental benefits of hydrogen-powered transport. The shift to hydrogen-powered transportation has significant economic and environmental implications. It offers a pathway to reduce dependency on fossil fuels, decrease air pollution, and mitigate greenhouse gas emissions, contributing to the goals of the Paris Agreement and global climate change mitigation efforts. The integration of hydrogen technologies in transportation is set to revolutionize the sector, offering sustainable, efficient, and clean solutions that align with global energy transition and decarbonization objectives.

5.2 Hydrogen for grid balancing and energy storage

The role of hydrogen in grid balancing and energy storage is increasingly pivotal as the world shifts toward renewable energy sources. Hydrogen serves as a key enabler for the integration of intermittent renewable energy sources like wind and solar power. By converting excess electricity into hydrogen, it acts as an energy buffer, ensuring that surplus renewable energy is not wasted but stored for future use.

Hydrogen technologies offer grid balancing services by providing demand response capabilities. They can quickly release stored hydrogen to generate electricity during peak demand periods or when renewable energy supply is low, thereby maintaining grid stability and reliability. Unlike batteries that are typically used for short-term energy storage, hydrogen can be stored for long durations without significant losses. This characteristic makes it ideal for seasonal storage, enabling energy systems to overcome periods of prolonged energy surplus or deficit.

Hydrogen can be produced and stored at a local level, supporting the decentralization of energy systems. This local production and utilization of hydrogen contribute to reducing energy transmission losses and enhancing local energy resilience. Hydrogen plays a crucial role in sector coupling, linking the electricity sector with heating, transport, and industry. By converting electrical energy into hydrogen, it can be used across different sectors, promoting an integrated and flexible energy system.

The future of hydrogen in grid balancing and energy storage looks promising, with ongoing innovations aimed at improving the efficiency, scalability, and cost-effectiveness of hydrogen-based energy storage solutions. As renewable energy adoption grows, the importance of hydrogen in ensuring a stable, reliable, and sustainable energy grid becomes increasingly significant. Hydrogen’s versatility and energy storage capacity position it as a key player in the transition to a more resilient, efficient, and sustainable energy system, particularly in the context of increasing global renewable energy penetration.

5.3 Hydrogen in industrial processes

The utilization of hydrogen in industrial processes (Figure 8) is a transformative approach, heralding a new era of sustainability and efficiency in various sectors. Hydrogen is instrumental in decarbonizing heavy industries like steel, cement, and chemicals. These sectors, traditionally dependent on fossil fuels, are now exploring hydrogen to reduce their carbon footprint, leveraging its clean combustion and high-energy content. Integrating hydrogen into industrial processes enhances efficiency, reduces waste, and promotes cleaner production methods. Hydrogen’s role in processes like refining, ammonia production, and methanol synthesis is evolving, driven by the demand for greener practices.

Figure 8.

Hydrogen applications [27].

In industries where high-temperature heat is essential, hydrogen is emerging as a key energy carrier. Its combustion releases water vapor, providing the necessary energy without the carbon emissions associated with coal or natural gas. Research and development are paving the way for innovative applications of hydrogen in industries, including its use in advanced manufacturing, as a reducing agent in metallurgical processes, and in creating sustainable synthetic fuels. The industrial adoption of hydrogen is supported by evolving economic and policy frameworks that incentivize clean energy use. Investments in hydrogen infrastructure, subsidies for clean energy, and carbon pricing are pivotal in integrating hydrogen into industrial applications.

The future of hydrogen in industrial processes is linked closely with global sustainability goals. As industries aim to reduce their environmental impact, hydrogen stands out as a versatile and clean solution that aligns with the global shift toward renewable energy and circular economy principles. Hydrogen’s integration into industrial processes is not just an innovation in energy use but a necessary step toward achieving a sustainable industrial future, reducing global carbon emissions, and facilitating the transition to a clean energy economy.

6. Conclusions

In this comprehensive exploration of hydrogen technologies, we delved into the latest advancements and innovative applications shaping the future of energy and industry. From cutting-edge developments in hydrogen production, including electrolysis, photoelectrochemical processes, and biological systems, to sophisticated storage solutions like solid-state materials, liquid organic hydrogen carriers, and advanced composites, the chapter has highlighted hydrogen’s pivotal role in the clean energy transition.

It also examined hydrogen’s expanding footprint in utilization sectors, showcasing its impact in fuel cells and combustion processes and as a transformative agent in chemical synthesis. The narrative further extended into hydrogen’s emerging roles, illustrating its potential in transportation, grid balancing, energy storage, and industrial applications, underscoring its versatility and adaptability across various sectors. The strategic importance of hydrogen technologies in achieving energy sustainability and climate goals cannot be overstated. As a clean, flexible, and efficient energy carrier, hydrogen stands at the forefront of the global shift toward a sustainable, low-carbon future. It bridges the gap between renewable energy sources and their integration into our daily lives, offering solutions for storage, transport, and decarbonization challenges that are critical for the energy transition.

This chapter’s insights reflect a vision where hydrogen technologies are integral to our energy ecosystem, driving innovation, bolstering economic resilience, and paving the way for a sustainable environmental legacy. The collective advancements in hydrogen technology encapsulate a future where energy systems are interconnected, efficiency is maximized, and carbon emissions are significantly reduced, heralding a new era of energy that is clean, adaptable, and sustainable.

Conflict of interest

The authors declare no conflict of interest.