Climate Action and Hydrogen Economy

Achieving net zero at the earliest is essential for the survival of mankind. The latest IPCC reports make it clear that time is running out. With present trends global warming is set to not only cross 1.5° considered essential by science, but to go well over 4° by 2100. This would make the planet uninhabitable. The sanguine confidence in some quarters that either the science is wrong, or, that technology would achieve some miraculous breakthrough in carbon capture that would enable us to continue using fossil fuels without adding to carbon emissions and global warming is delusional. Immediate course correction for rapid decarbonization on a massive scale is required if there is to be any hope. :

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India has committed to reduce the emissions intensity of its GDP by 45% by 2030, as compared to 2005 levels, under the Paris Agreement on climate change. A shift in energy production and use can be a key starting point to drive these commitments. Green hydrogen (GH)-driven energy is emerging as a viable alternative to fossil fuels and battery-powered mobility systems. Strong hydrogen demand growth and the adoption of cleaner technologies for its production enable green hydrogen-based fuels to avoid up to 3.6 Gt CO₂ emissions between now and 2050 to contribute towards net-zero vision and climate risks. Developed economies like the European Union, Australia, and Japan have already drawn a hydrogen roadmap to achieve green economic growth. Developing countries like India can also decarbonize their energy-intensive sectors such as industry, transport, and power by moving towards hydrogen economy. India has announced National Green hydrogen Mission and is adopting GH-based economy by working on R&D, especially with respect to technology development and advancement, finding import substitutes, formulating guidelines and policies on environment, health and safety. Stakeholders’ engagement is also vital for harnessing the power of this green fuel to reduce the impacts of climate change and promote Aatma Nirbhar Bharat. The chapter outlines the potential benefits of using GH as a vital part of the total energy basket and further developing a national road map for hydrogen that supports a stronger and faster energy transition beyond India’s current climate change initiatives. Towards the end, a possible way forward has been suggested for harnessing the power of GH that can help capitalize on value creation.

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Net zero is a massive plan to constrain the global temperature rise to less than 1.5 °C whereby annual GHG emissions must be reduced from ~36.6 Gt to less than 10 Gt by using non-carbon renewable energy sources. Green hydrogen will play a huge role in transforming C1 off gases like CO₂ into valuable chemicals and materials. Both blue and green hydrogen will contribute about 24% in the renewables totaling to about 539 to 820 MMTA in 2050. (Waste) Biomass will be transformed into fuels, chemicals and materials using hydrogen and oxygen derived from water splitting. Waste plastic can be chemically recycled into several hydrocarbons and depolymerized into monomers using different techniques, and hydrogenation will be very effective in tackling plastic pollution. Hydrogen is a key component in converting waste to wealth. Green hydrogen is poised to be a savior of the world. The concept of CO₂ refinery is discussed, and use of biomass and plastic waste toward hydrogen economy is described.

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Global warming and its devastating effects on the climate have awakened the world to the reality that using fossil fuels as a source of energy is not sustainable. Natural processes of hydrocarbon generation and accumulation, which take millions of years, cannot be undone in decades without paying a heavy price. Renewables and hydrogen could be the alternative to fossil fuel, but the transition process can only be bumpy, for it is only in the recent past that this change is being initiated. This paper gives a perspective on the state of development of the alternate sources of energy including investments, the technological and policy challenges. Decarbonisation methods, essential to keep carbon dioxide levels in the atmosphere within limits, in the intermittent period have also been discussed. Geopolitics and economics have played a significant role in ensuring supply of fossil fuel during the last few decades, which resulted in the economic development of the Middle East. All this is also likely to change and countries, which have a rich endowment of rare earth metals, essential for production of alternate energy and their processing facilities, will reap the benefits. Monopoly in the resources required for development of alternate energy can create issues of energy security and this needs to be checked for a sustainable global development. Absence of cheap fossil fuel energy can enhance development cost which the non-OECD (organisation for economic cooperation and development) countries will have to bear, besides devastations due to global warming. Whether OECD countries will compensate poorer countries against this devastation is anyone’s guess. Managing a smooth transition from fossil fuel to hydrogen and renewables before irreversible climate change occurs is the challenge mankind is facing today. Human beings, today are confronted with two alternatives i.e. to transform energy sector to renewable based or perish.

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From the year 2019 to 2021, solar power generation increased by 47%, wind by 31% worldwide and it is interesting to note that to meet the growing demands of power and limit to 1.5° warming, the share of renewable energy of the world needs to be increased to 75% by 2030. Although COP 27 has outlined that limiting the warming to 1.5° would be difficult if countries keep shifting their targets. For India, transition to Net zero emission future may require an investment of $3 trillion over three decades and we need to phase down the usage of coal and revamp the use of renewable energy production along with hydrogen production. Green hydrogen will prove to be a milestone to achieve Net zero targets. This chapter gives a review of the energy transition in India and highlights the need of Science, Technology and Innovation Policies that provide a push towards turning India into a hydrogen economy. Lastly, the chapter emphasizes the need for financing and improved technology for increasing hydrogen with a major emphasis on green hydrogen. The Hydrogen Energy transition in India is a long process that needs technology, R&D, funding and policy support from the government, private players and academia alike.

In the language of design and systems design, we are confronted with a “wicked” problem of sustainability, with a capital S. The path out of addressing the effects of climate change, appears non-linear, uncertain, and material. Energy and economic choices may well collide with climate constraints. Firmly rooted in the complexities of the inter-related energy and economic systems, sustainability has over the last year reached the boiling point of a Net zero future articulated by countries and companies. Approximately 90% of global greenhouse gas (GHG) emissions are covered by Net zero pledges, but with different strength and timing. In the quest for the planetary balance that is central to Net zero ambitions, India and India Inc are no exceptions. The classic dilemma of development and its associated carbon footprint, that are foundational to our energy mix and choices, exists.

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In COP26 summit-2021 in Glasgow, India made commitment to replace 50% of its fossil fuel/coal technology with green fuel by 2030. The process for the conversion of water into hydrogen using full spectrum of natural sunlight needs long-term strategy. This chapter provides glimpses of approaches pursued by our group being pursued to address the ongoing technical issues and shortfalls for hydrogen generation technology. This is being pursued by implementing different strategies such as newer design of hybrid materials and systems, increased solar to hydrogen conversion efficiency and scaling and piloting technology. Plasmonic bimetallic Au-Pt, Cu-Pt and Ag-Pt titania composites have been developed and tested for photocatalytic water splitting in photovoltaic (PV) panel coupled 30 Ltr capacity photoreactor system showing hydrogen evolution rate (HER) ranging from 12 mmol/h/400 mL to 17 mmol/h/400 mL which is exemplary by considering the uses of solar generated energy. Functional PV-based facilitated Water Electrolyzer (WE) system is showing promising leads of HER of 1.12 L/min.

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The discovery of graphene nanosheets (NSs) opened a flood gate of activities for studying graphene and graphene like hexagonal lattices. Particularly, the photoelectronic properties of these 2D-layered materials are of significance as they can be modified by changing their atomic arrangements. The zero-band gap of graphene did not in principle favour for switching applications against silicon. In contrast, graphitic carbon nitride (GCN), closely resembling graphene, exhibits semiconducting behaviour with excellent photoelectronic properties. GCN could photocatalytically produce H₂ by water splitting in the presence of solar radiation. Extensive theoretical and experimental studies are currently going on to convert it not only into quantum dots (QDs) and nanotubes (NTs), but also to conjugate with other 2D-NSs. The introduction of lattice defects during doping and heterojunction formation in combination with other 2D nanomaterials turned out useful in influencing photogenerated charge carrier recombination and subsequent transport properties enabling them to participate in redox reaction at the surface. This entire process of photocatalytic effect in ideal monolayer of GCN-NS involving intermediate steps like photogeneration of electrons and holes, exciton formation, charge carrier separation, and subsequent participation in redox reaction, to generate hydrogen from splitting water, has theoretically been simulated using DFT models to understand the details at different timescales and spatial resolutions. The experimental side of developing GCN-NSs based photocatalysts has not been without challenges. This chapter describes about the salient progress made in preparing GCN-NS-based photocatalyst for H₂ generation available from the current publications. It is still too early to say that these photocatalysts would be crossing the viability barrier of 10% for their large-scale applications in meeting the global green energy alternative in place of fossil fuels and reaching the zero pollution.

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Hydrogen is light, storable, energy heavy and does not produce direct carbon emissions or greenhouse gases (GHG). So, hydrogen can play an important role in any decarbonization strategy. It will not only help in integrating increasing RE into the grid sustainably but can also decarbonize hard to abate sectors like petroleum, steel, cement, fertilizers, transport, etc. Presently, green hydrogen from electrolysis of water costs twice that of grey hydrogen but with alternate technologies, soon it may be available at less than $1/kg. Green hydrogen can be produced from renewable feedstocks like waste, biomass, sewage sludge, etc. Processes for hydrogen production from waste include gasification, pyrolysis, anaerobic digestion, steam methane reforming, dry reforming, methane splitting, etc. Global waste generation is over 2.0 billion tons and expected to grow about 3.5 billion tons by 2050. Out of various hydrogen production routes, analysis indicates hydrogen from biomass/waste not only can be produced at least cost but also can reduce air, water and soil contamination. Moreover, hydrogen from waste produced in decentralized manner can reduce hydrogen transport cost. Further, green hydrogen can facilitate faster and sustainable energy transition cutting energy imports for India. Green hydrogen can make India self-reliant and facilitate its journey towards carbon neutrality.

Nature fixes hydrogen as an element in only two compounds: water and biomass. Biomass, a typical C_XH_YO_Z compound produced naturally through the process of photosynthesis, on a specific basis, contains about 520 g of carbon and about 61 g of hydrogen with the balance being oxygen. In the process of gasification, under sub-stoichiometric auto thermal conditions, biomass is converted to hydrogen-rich synthetic gas when using superheated steam and oxygen as the gas phase reagents. Operating in the stoichiometry range of 0.25 to 0.30 and steam to biomass ratio of 2.0 to 2.5, hydrogen-rich syngas, of typical composition 45% H₂; 15% CO; 5% CH₄; 10% N₂ and 25% CO₂, is generated which contains close to 135 g of H₂ per kilogram of biomass. It is important to note that while biomass contains only about 61 g of H₂ the enhanced yield in syngas is due to the contribution by both biomass and steam. The patented gasification system is configured to leverage the carbon present in the biomass to act as a reducing agent for steam and thereby generate additional H₂. The syngas so generated is subjected to swing adsorption-based separation adopting a patented configuration and operating on an adapted Skarstrom cycle. The separation system generates bio-hydrogen of desired quality and has been tested exhaustively over a range of capacities to generate ISO 14687-2019 Type I Grade D quality H₂ at recovery factor of over 75%. On the realized recovery basis, every kg of dry biomass yields 85 g of ISO 14687 quality H₂. It is important to mention that every kg of H₂ generated through the gasification route fixes close to 300 g of solid carbon in the form of char, which on equivalent basis amounts to about 1.1 kg of carbon dioxide. Thus, the system is inherently carbon negative and coupled with carbon capture technologies, and it is possible to capture close to 12.5 kg of carbon dioxide per kg H₂.

The current global energy requirement is primarily dependent on conventional fossil fuels (coal, oil, and natural gas), which invariably emit a copious amount of CO₂, leading to adverse climate change effects. Therefore, it is highly commendable to search for carbon footprint-free energy alternatives. Renewable energy resources (solar, wind, tidal, etc.) have emerged as apt alternatives to resolve this conundrum; however, they require a stable energy vector due to their intrinsic intermittence. Hydrogen molecule fits the bill as it can be directly used in a fuel cell for energy production, following a greener pathway. Therefore, hydrogen production has become a bustling research area via sustainable methods. Since water is an abundant resource of protons and covers over 71% of the planet, hydrogen evolution from water becomes useful. Hydrogen can be produced from water through electrical, photochemical, and biological means. Among these methods, water electrolysis is regarded as one of the environmentally friendly techniques to produce hydrogen. Besides this, hydrogen can also be generated via the photochemical splitting of water, where solar energy can be directly involved. Here in this chapter, we have depicted the recent advancements in electrochemical and photochemical hydrogen production using bio-inspired molecular catalysts.

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Considering the ever-increasing carbon emission and its severe consequences on the global temperature, it is essential to explore sustainable energy resources with minimal or zero-carbon footprint. In this regard, hydrogen has emerged as a promising sustainable candidate to meet the global energy demand, primarily because it has high energy density and produces only water/water vapor upon usage in the fuel cell or combustion. However, sustainable production, safe storage, and transportation of hydrogen gas are challenging. Therefore, several hydrogen storage materials/carriers have been explored to store high gravimetric and volumetric hydrogen content and release and store hydrogen gas on demand. In this regard, being liquid at room temperature, the liquid hydrogen carriers offer the additional advantage of easy and safe storage, transportation, and dispensing. Further, these liquid hydrogen carriers contain high H₂ content, which can be released on demand. Moreover, most liquid hydrogen carriers can also be regenerated from CO₂ and biomass waste. Therefore, it is worth highlighting the potential of these liquid hydrogen carriers as promising candidates for hydrogen storage and production in a sustainable way.

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Low-temperature electrochemical hydrogen production process, such as proton-exchange membrane electrolyzer and alkaline electrolyzer, uses expensive noble metal catalysts and requires higher electrical energy for water oxidation. A solid oxide electrolysis cell (SOEC) operating at a higher temperature provides a highly energy-efficient and cost-effective route of hydrogen production with comparatively less electricity consumption. Moreover, the use of less expensive ceramic electrolytes and electrodes has added a value to its application. Proton (H⁺)-conducting solid oxide cell (H-SOEC) provides the scope of dry and pure hydrogen production at reduced temperature (<600 °C). It also provides the scope for compressed hydrogen production via electrochemical compression. SOEC can be operated reversibly in solid oxide fuel cell (SOFC) mode to generate electricity utilizing the produced hydrogen when renewable power sources are unavailable, with only water as the byproduct. In the case of SOEC, there lies the scope for large-scale hydrogen production as the stack size can be scaled up to MW range. Besides generating hydrogen from H₂O, SOEC provides the advantage of H₂ production from NH₃, converting CO₂/CO to value-added chemicals and converting CH₄ and C₂H₆ to olefins. This chapter starts with a distinctive comparison of hydrocarbon and hydrogen economies, then proceeds with a thorough review of the mechanism of water electrolysis in both proton- and oxide-conducting electrolysis cells, different electrolytes and electrode materials used, and their operating mechanisms. The chapter also discusses the thermodynamic and electrochemical aspects of electrolysis, current–voltage characteristics, Faradaic efficiency, and hydrogen generation rate of SOEC. There is a detailed coverage on the durability and market competitiveness aspects of SOEC at the end.

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Energy is directly related to a nation’s currency. Without a doubt, it is always in high demand, but regrettably, the supply is always insufficient to match the unprecedented population growth and our altering lifestyle. Regarding energy consumption, India ranks fifth in the globe. The gap between demand and supply of commercial energy is increasing exponentially, indicating a growing reliance on oil imports from oil-rich nations. Clean coal technologies and an increasing proportion of hydro, nuclear, and renewable energies comprise India's sustainable energy path for electricity production. Alternative fuels for surface transportation are bio-fuels electric vehicles, hydrogen, and fuel cells vehicles. Decades of dedicated R&D have revealed that hydrogen is an ideal candidate as a clean energy carrier for both transportation and stationary applications in the quest for alternative fuels. The difficulty of storing and transporting hydrogen proficiently and cost-effectively is one of the most significant obstacles to its use as a fuel. Its use at a suitable location necessitates storage, a crucial aspect of the overall hydrogen energy concept. Both high-pressure gaseous (heavy weight and dangerous mode) and liquid (expensive cryogenics, thermal, and ortho-para conversion losses) form of storage are impractical. The chemical storage of hydrogen in the form of metal hydrides is an attractive alternative that is the subject of intensive international R&D efforts. In India, a number of significant hydrogen energy programmes are being conducted by a variety of institutes. Special efforts have been made to develop novel storage materials that are reversible, inexpensive, and simple to mass produce. Our group has made significant advancements in the field of hydrogen storage materials. Various prospective nanotechnology avenues for reducing the temperature at which hydrogen desorbs and improving the reversibility of future hydrogen storage materials are outlined.

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India is the second largest consumer of fertilizers in the world. One of the most important fertilizers consumed is urea, which is a carrier of nutrient nitrogen. Ammonia is an intermediate required to produce urea and other nitrogen containing fertilizers. India is expected to produce 20 million tonnes of ammonia by 2024–25. India also imports 2.5 million tonnes ammonia, which is expected to go up. There are 16 coastal locations and dozens of inland locations, where ammonia is produced/imported and stored. Ammonia is also transported over short distances through road, rail and pipelines. Ammonia produced from natural gas can be replaced by green ammonia. It is the easiest to utilize green ammonia to produce non-urea fertilizers. The requirement for this segment is about 3 million tonnes ammonia. Initially, green ammonia will be more expensive and there is a need for viability gap funding. Green ammonia plants can be located either next to power plants or near the consumers, mainly fertilizer plants. This chapter has following learning.

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