Articles
Hydrogen hubs: Materializing Indian aspirations
Special Focus: H2 Mobility, Transportation and Infrastructure
MP SUKUMARAN NAIR, Green Technology and Management, Kerala, India
The transition to hydrogen (H2) from fossil fuels has become a vital subject in all global discussions relating to climate change, economic development, waste elimination and pollution reduction. This implies that H2 production, storage, pipelines and dispensing stations will–like petrol and gas stations have–expand to widely distributed networks and become commonplace. These networks will involve significant infrastructure development across all segments of the H2 economy. Several countries and multinational corporates have adopted a strong commitment to the targeted achievement of net-zero emissions and have taken up green H2 and ammonia projects, including hubs for domestic distribution and export. This article will analyze how such H2 hubs can be planned, executed and operated.
Seeking zero-carbon fuels. Anthropogenic activities are now considered the driver of climate change, due to the burning of fossil fuels like coal, oil and gas that generates greenhouse gas (GHG) [mostly carbon dioxide (CO2) and methane] emissions that act like a blanket wrapped around the Earth, trapping the sun’s heat and raising atmospheric temperatures. The energy generation, industry, transport, buildings, agriculture and land use sectors must decrease their GHG emissions. Therefore, the replacement of fossil fuels with little or no carbon emissions has become the primary agenda for mitigating the climate crisis.
COP28 decisions. At the United Nations Climate Change Conference (COP28) held in Dubai, 198 nations endorsed an agreement to initiate the “beginning of the end” of the fossil fuel era by laying the groundwork for a swift, just and equitable transition through deep emissions cuts and establishing a fund to address the damage and losses that vulnerable countries face from climate change. The COP28 Declaration of Intent calls for H2 to be prioritized as a replacement for fossil fuels. It also launched initiatives to unlock the climate and socioeconomic benefits of H2 as a prelude to a shift to the H2 economy. A net-zero world would require 306 MMtpy of green H2 by 2050, according to the International Energy Agency (IEA). This would, by then, require around 6,000 gigawatts (GW) of renewable energy and 3,000 GW of electrolyzers, based on available technologies.
H2 as the fuel and feedstock. A shift in major energy production centers is expected from fossil fuel-rich countries to those blessed with sunshine, wind and abundant water. Global demand for renewable H2 is expected to grow steadily over the coming decades. According to the IEA’s Global H2 Review 2023, global H2 demand was 95 MMtpy in 2022 and is set to reach 157 MMtpy by 2030. By then, H2 hubs and export terminals will be as common as liquified natural gas (LNG) terminals. The European Union (EU) has set a target to import 10 MMtpy of renewable H2 by 2030, with Germany, the Netherlands and Belgium expected to be major importers.
India has the advantages of an abundant supply of renewable power, growing domestic and local international markets, experienced and advanced technological capabilities, and energy infrastructure that will help to store, transport and deliver H2 at a low cost. India can position itself as a major supplier of green H2 and can become a top exporter of H2 to the growing global market. Here lies the importance of building H2 hubs at major port locations in the country, and having storage facilities linked to production sites, a pipeline network and truck/rail loading facilities for local delivery and ship-loading facilities for export.
According to the European Commission’s H2 strategy, H2 produced using renewable resources costs between $2.58/kg and $6.40/kg, whereas fossil-based H2 costs around $1.76/kg. India already consumes > 6 MMtpy of gray H2 used for petroleum refining and fertilizer production. Most global green H2 market surveys project a compound annual growth rate (CAGR) of 40%−50% from 2022 to 2030. The projected demand for H2 by 2030 would be around 11 MMtpy, of which 5 MMtpy are expected to be green as per the National Green H2 Mission. The Government of India intends to incentivize domestic electrolyzer manufacturing and green H2 production to reach 5 MMtpy of green H2 production by 2030. Policy initiatives to mandate the use of green H2 (starting with 10%) in industries such as steel and petroleum refining are also expected. In July 2020, the production cost of green H2 was around $5.96/kg and the Government of India proposes to cut the cost by 40%−50%, according to the policy initiatives.
Infrastructure. A H2 hub is a network of H2 producers, connected pipelines and other related infrastructure intended to store and deliver tremendous amounts of green energy. Most countries are planning to create clean H2 facilities as a key pathway to building large commercially viable ecosystems for dispensing H2. These H2 hubs will enable the energy transition to low carbon-intensive and economically viable energy ecosystems that can replace existing carbon-intensive fossil fuels. Thus, the hub consists of facilities for production, processing, delivery, storage and end use of clean H2 across all consumption sectors and is crucial to achieving national climate goals and net-zero carbon emissions targets (FIG. 1).
The infrastructure required for a H2 hub to produce and distribute green H2 includes equipment for the generation and delivery of renewable power, facilities for water treatment to produce ultrapure water, cost effective and efficient electrolyzers, H2 handling equipment, compressor systems, storage, pipelines, associated safety systems, instrumentation, utilities and other services. Petroleum refiners and operators of fertilizer or methanol plants are quite familiar with the bulk of infrastructure requirements. In India, there is no lack of experience with these technologies, as the country has several world-class plants operating to date with various technologies (FIG. 2).
The colors of H2. The colors of H2 are intrinsically associated with its carbon intensity and nature of energy used for its production. Green H2 is produced through water electrolysis using renewable power such as solar, wind, hydro or geothermal. Gray H2 is produced by the conventional steam methane reforming (SMR) route over a nickel catalyst in a reforming furnace, which uses fossil fuel. If the CO2 associated with H2 production in the SMR route is sequestered through a carbon capture and storage (CCS) mechanism, the color of the H2 becomes blue. H2 produced through the pyrolysis of methane (thermal, catalysis of plasma), along with the production of carbon powder, is called turquoise H2. If nuclear power is used to produce H2, either for electrolysis or pyrolysis, it becomes pink or red H2 (FIG. 3).
Renewable power. India is already a global leader in green power development with an installed solar photovoltaic (PV) capability of 72.31 GW in August 2023, and wind power projects with a capacity of 44 GW. The combined renewable energy installed capacity is 176.5 GW and is targeted to reach 500 GW by 2030. India aims to reach the lowest levelized cost of green electricity (LCOE) by employing renewable energy around the clock supply (RE-RTC) plants, including wind, solar PV, battery energy storage systems (BESSs), pumped hydro storage projects, a waiver in interstate transmission system (ISTS) charges and by allowing banking of power projects. The LCOE accounts for 60%−70% of the levelized cost of H2 (LCOH). Along with domestically manufactured electrolyzers, low-cost green power can bring down the LCOH to $3/kg−$4/kg, which is now hovering around $5/kg−$8/kg.
Water. According to an IEA report, nine liters of ultrapure water is needed for every kg of green H2 produced. Electrolyzer manufacturers commonly specify that water quality must meet the American Society for Testing and Materials (ASTM) standards for Type I or Type II water. Potential water sources for electrolysis are oceans (seawater), estuaries, surface waters (rivers, canals and lakes), ground water, rainwater, water from municipal supplies or recycled water (treated urban or industrial wastewater). The report highlights that freshwater access becomes a concern in water-stressed areas when producing green H2.
To produce 6 MMtpy of green H2, estimates suggest that India would require anywhere between 132 million cubic meters (MMm3)−192 MMm3 of water. The World Bank has classified India as one of the world's most water-stressed countries because it only has enough water resources for 4% of its population, despite having 18% of the world's population. Chandigarh, Haryana, Rajasthan, Uttar Pradesh, Punjab, Madhya Pradesh and Gujarat are states with acute water shortages. To meet the increasing demand of water from the industry, the Government of India and the states must effectively protect and preserve their water resources, optimize uses in every sector and strengthen water harvesting and conservation efforts through policy initiatives.
Electrolyzers. To meet the 2030 production target of 5 MMtpy of green H2, India will need at least 60 GW of installed electrolysis capacity. Electrolyzers are used to split water into its elements using electricity. Water electrolyzers are divided into four different types based on the nature of the electrolyte used and the operating temperature (FIG. 4).
The types of electrolyzers include alkaline, polymer electrolyte membrane (PEM), anion exchange membrane (AEM) and solid oxide electrolyte (SOEC) electrolyzers. Alkaline and PEM electrolyzers are mature technologies and already commercialized, while AEM and SOEC electrolyzers are in their development and near-commercialization stage. The Government of India has sanctioned $2.2 B for the Strategic Interventions for Green H2 Transition (SIGHT) scheme to develop the green H2 ecosystem; however, this is not enough. India must create a strong local electrolyzer manufacturing base through domestic and collaborative research. India has all the resources needed to undertake innovative research and development projects in this area.
Incentives. The creation of a 5-MMtpy capacity for producing green H2 by 2030, along with an additional 125 GW of renewable energy capacity, may require an investment of $95 B. Besides reducing the country’s oil and gas import bill by $11 B, it will also generate 600,000 jobs, as well as cut down nearly 50 MMtpy in GHG emissions. The government under the SIGHT program has already allocated $208 MM in the annual budget 2022–2023 to provide incentives for green H2 projects and the manufacture of electrolyzers. A further $17 MM would be allocated for pilot projects, while $4.7 MM and $4.6 MM will be used for research and development and other mission components, respectively. The government is also planning to waive import duty on electrolyzers and include manufacturing electrolyzers under the production-linked incentive (PLI) schemes. India offers carbon credits for green H2 production in exchange for investments from other countries. This has helped collaborative projects with other countries involving government and industry.
India launched the National Green H2 Mission (NGHM) in 2023, which aims to produce 5 MMtpy of green H2 and 125 GW of renewable energy at an investment of $100 B. The NGHM will serve to create more than 600,000 jobs, achieve a reduction in fossil fuel imports of $12.5 B and abate 50 MMtpy of GHG emissions. The World Bank supports India’s green H2 agenda through analytical studies to replace existing gray H2 produced from natural gas in the fertilizer and refinery sectors, identify suitable locations for green H2 hubs and support selected states in developing their own green H2 adoption roadmaps.
Quality of H2. The Ministry of New and Renewable Energy (MNRE) has developed the green H2 standard for India, specifying the emissions thresholds during its production. The definition includes green H2 production through water electrolysis and biomass processing. It defines green H2 as having less than 2 kg of CO2e emissions per kg of H2 taken as an average over the previous 12-mos period for electrolysis-based and biomass-based plants. This also includes cumulative emissions during upstream and downstream processing such as water treatment, electrolysis, biomass processing, gas purification, drying and H2 compression. Detailed methodologies for measurement, reporting, monitoring, onsite verification and certification of green H2 and its derivatives will be specified by the MNRE. The Bureau of Energy Efficiency (BEE) in the Ministry of Power is entrusted to accredit agencies for the monitoring, verification and certification of green H2 production projects.
H2 pipelines. The material selection and design of H2 piping systems are usually accomplished in accordance with the American Society of Mechanical Engineers (ASME) standard B31.12 titled “H2 piping and pipelines, other applicable codes and regulations, and the special requirements for H2 service.” Austenitic (300 series) stainless steels meeting the temperature limits of ASME B31.12 are recommended for liquid and gaseous H2 product piping, tubing, valves and fittings. The most stable grade is Type 316/316L, which is relatively immune to H2 embrittlement when exposed to high-pressure H2. Low-alloy carbon steels with high-carbon content and high-strength are susceptible to embrittlement and crack propagation. The use of carbon or alloy steels requires tensile strength control, heat treatment, microstructure and surface finishes, as well as initial and periodic examination for inclusions and crack-like defects when in cyclic service. Usually, plastic piping and tubing are not used in H2 service. The use of available natural gas pipelines for H2 transportation must be considered as the construction of dedicated H2 pipelines involves a high investment. Natural gas pipelines allow a safe blending of 20% H2.
H2 storage. Generally, H2 produced in an electrolyzer is done at lower pressures and will be pressure boosted for storage and pipeline transport using compressors. H2 compressors have a high standard of safety. There are four different types of storage for H2. Gaseous H2 is stored at ambient temperatures in bullets made of carbon steel or stainless steel with typical pressures ranging from 350 bar−700 bar.
The H2 is compressed, liquified and stored under atmospheric conditions at −252.8˚C in specially designed cryogenic storage tanks. For cryogenic H2 storage, aluminum is the preferred material of construction due to its low density, superior mechanical properties and better compatibility to low temperatures compared to cryogenic nickel alloy steel (FIG. 5).
An alternative to compressed and liquefied H2 storage is materials-based storage, which binds H2 through physical adsorption or chemical combination. This includes metal hydrides of elements such as palladium (which can occlude 900 times its own volume of H2), magnesium, aluminum and certain alloys. Storing ammonia as a H2 carrier is another option. The energy density by volume of ammonia is nearly double that of liquefied H2, making it far easier to store and transport.
Apart from cryogenic storages and pressurized bullets, H2 is also stored within other materials such as metal hydride in its occluded form. Here, H2 is bound to metal alloys in porous and loose form by applying moderate pressure and heat, and can be subsequently extracted. While this form of storage is technologically feasible and safe, metal hydride and other H2 storage methods within solid materials are not an economic option for storing large volumes of H2.
Storage of gases in underground salt caverns is well known, but geological H2 storage in depleted oil fields and aquifers is another option. One such project, the Advanced Clean Energy Storage Hub, is under construction in Utah (U.S.) through a joint venture (JV) between Mitsubishi Power Americas and Magnum Development. It will have a deep underground salt dome that covers more than 4,800 acres—each cavern will be about 67 meters (m) in diameter and 580 m in height.
Major user segments. Major uses of green H2 include power generation, steel making, chemicals and petrochemicals production, cement production, manufacturing ammonia for the fertilizer industry, and as an energy source to power heavy industry and fuel large vehicles, including aircrafts and ships. Producers and technology providers are jointly assessing the feasibility of low-carbon economic capacity plants in the global fertilizer, chemical, steel, cement, energy and shipping industries.
Delivery dispensing. The process of refueling at a H2 station is similar to a conventional petrol or gas station. H2 is supplied at a high pressure of 100 bar–300 bar: since it is a very light gas, all the joints and connections must be extremely leak proof. Specially designed dispensers are used to pump H2 into the vehicle's fuel tank, which powers the fuel cell that generates the electricity needed to drive the vehicle or the H2 internal combustion engine (ICE). In either case, the exhaust after combustion is only water vapor.
H2 engines. Gaseous H2 as a fuel can be used to power an engine or motor in three ways. The first involves a fuel cell that converts H2 to electricity and powers the equipment’s electric motors. The second method is an ICE (similar to automobile engines) that burns H2 as the fuel. A third method is a H2 reaction engine that uses H2 in its liquid form, and liquid oxygen is injected into the combustion chamber of gas turbines/rockets as a propellant. Such reaction engines are used in aerospace and aeronautics applications.
H2 fuel cells. The chemical energy of H2 is converted to electricity in the H2 fuel cell. H2 is oxidized with oxygen in the atmospheric air to generate heat, water vapor and an electric current without producing GHG emissions. The electricity generated is used to run a motor to convert it into other forms of mechanical energy. The technology is proven, and the combustion efficiency is around 50%–70%.
Ammonia engines. The difficulties experienced in handling H2 and the associated extra safety measures are better addressed through its conversion into ammonia and use as a fuel in ICEs. In today’s green energy market, ICEs are competing with electric propulsion. ICE designs of today are robust and command several large high-performance installations, both mobile and stationary compared to electric propulsion, which is still under development. Therefore, green ammonia is emerging as a promising ICE fuel that is carbon free, has a relatively high-volume energy density, and is easy to store and transport as established through several installations worldwide. Burning ammonia in existing engine architecture with retrofitting modifications have attracted long-distance sea transporters in their efforts to reduce the carbon intensity of shipping despite the poor combustion properties of the fuel, such as a high autoignition temperature and low burning velocity. Moreover, international rules for ships using ammonia as fuel are not yet in place, and discussions on this issue are underway at the International Maritime Organization (IMO). Using combustion improvers and the onboard production of H2 from ammonia cracking through engine heat recovery will likely improve thermodynamic limitations.
H2 safety. Compared to other common fuels, H2 has the lowest boiling point (−253˚C), lowest density (70.8 kg/m3) and lowest energy density (8.51 MJ/l). It also has the highest lower heating value (120.2 MJ/kg) and highest autoignition point (585˚C), next only to ammonia (630˚C). Its low density helps it to quickly dissipate into the atmosphere when released in an open environment and escape into the upper atmosphere. It is a non-toxic gas, but its wide flammability range and potential for combustion raise concerns regarding H2 safety and hazard potential.
Cold burns result from contact with leaks, frosted lines, liquid air that may be dripping from cold lines or vent stacks, vaporizer fins and vapor leaks. Air will condense at liquid H2 temperatures and can become an oxygen-enriched liquid due to the vaporization of nitrogen. Oxygen-enriched air increases the combustibility of other flammable and combustible materials present nearby.
The International Organization for Standardization (ISO) has codified its technical report, titled “Basic considerations for the safety of H2 systems” to provide technical information highlighting H2 safety issues to guide designers and facility operators. It also addresses the interest in using H2 as a fuel and aims to address the unique H2-related safety properties and best engineering practices to minimize risks and hazards of handling H2. Safe and efficient H2 storage and its transport both on land and at sea will be critical for the development and viability of the global H2 value chain.
Takeaways. The success of any new mission depends heavily on the policies guiding its development. The retention pricing policy (1978) for fertilizer manufacturing in India paved the way for success in the sector for the country to become the second largest producer and consumer of mineral fertilizers globally. Similarly, policies to pool all available and related infrastructure, incentivize domestic production of electrolyzers and H2 infrastructure—with a well-defined roadmap for the decarbonization of difficult sectors like transport, steel, cement and chemicals—are important. These policies would incentivize private capital to collaborate and lead the energy transition and decarbonization efforts along with national institutions to boost green manufacturing, generate employment and capture global markets through exports. H2T
About the author
MP SUKUMARAN NAIR is the Director for the Center for Green Technology and management in Cochin, India. Nair is the former Secretary to Chief Minister and Chairman for the Public Sector Restructuring and Audit Board for the Government of Kerala, India.
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