R. Brutoco, World Business Academy, Santa Barbara, California
As the world increasingly seeks sustainable and efficient energy solutions, there is a general consensus that hydrogen (H2) will play a significant role. This makes the question of how this product is best transported not just a technical issue, but also one with profound environmental, economic and geopolitical implications. A growing number of policymakers and ammonia (NH3) industry proponents have recently begun to champion NH3 as the best way to transport H2 and as a viable alternative to pure H2 for various applications, including as a fuel for the maritime industry, an energy storage medium, and feedstock for electricity generation.
This perspective touts the potential of “green ammonia”—NH3 produced from H2 derived from renewable sources like wind, solar or hydropower—as a more practical and economically viable solution than pure hydrogen. This article examines this narrative, showing how it arises from two sources: first, from a limited perspective on the emerging opportunities provided by H2; and second, from a lack of awareness of recent advances in transport technologies for both gaseous and liquid H2. Based on an in-depth exploration into the production, storage, utilization, safety and economic aspects of both H2 and NH3, this work will show that pure, unadulterated H2 is a superior option in all cases except for the indispensable role green NH3 will play as a primary component in fertilizer production and within several niche markets now served by NH3 derived from non-renewable sources.
Background. The global energy landscape is undergoing a transformative shift in response to the challenges posed by global warming. For reasons discussed here, the success of this shift relies substantially on the development of a thriving green H2 economy. While electricity produced from renewable sources certainly plays a leading role, H2 is also essential to the success of this transition because there exists no other renewable, non-toxic and carbon-free fuel that can store energy as a chemical battery, generate electricity within both fuel cell and combustion-based systems, sustain “hard-to-abate” industries such as the production of cement and steel, and enable zero or near-zero emissions in aviation and long-haul trucking.
Green H2, when produced in regions where renewable energy is abundant and inexpensive, presently stands as an economically attractive alternative to fossil fuel. However, these regions are usually located far from the markets where large quantities of H2 are needed. While additional technological improvements and economies of scale are forecast that will reduce H2 production costs even more throughout the coming decades, there is growing awareness that for H2 to be economically competitive, it is essential to address the challenges and high costs associated with H2 transport and distribution.
H2's intrinsic attributes present formidable transport challenges. It has an exceptionally low energy density, effectively making the transport of large quantities of gaseous H2 by truck, rail or ship impractical and far too costly. Compression and liquefaction, while able to boost density, demand additional energy inputs, thereby requiring complex energy balance considerations to assess whether H2 delivery relying on these additional steps represents a viable substitute for fossil fuel products. Moreover, cryogenic storage and transport necessitate maintaining H2 at a staggering –253°C (–423°F), merely a few degrees above absolute zero.
In response to these formidable hurdles, attention has turned to the prospect of using “green NH3” as a green H2 carrier, notwithstanding NH3’s extreme toxicity. Although H2 contains about six times more energy by weight, has a faster rate of combustion and a higher level of heat generation, NH3 is > 30 times denser than gaseous H2 and 8.5 times more dense than liquid H2, making it easier to handle, transport and store (other than the toxicity issue).1
Because NH3 is carbon-free, has a higher H2 content (17.8% by weight) than other fuels, and has a narrow flammability limit, it is generally considered to be the most popular substance as a green H2 carrier. Converting pure H2 into NH3 necessitates comparable energy inputs as H2 liquefaction, yet it presents intriguing advantages. NH3 transitions to a liquid state at –33.34°C (–28.01°F) at standard pressure, and can be stored at 25°C (77°F), rendering it far more manageable than pure H2. Whereas new technologies still must be developed for long distance transport of cryogenic H2, significant expertise already exists regarding NH3 storage and distribution. Notwithstanding the additional safety protocols necessitated by NH3’s extreme toxicity, proponents argue that green NH3 presents a practical and economically superior solution to evolving global energy needs.
Some proponents envision NH3's utility not only as an energy carrier, but also as a fuel source in combustion engines and certain types of fuel cell applications. They argue that (like H2) NH3 has no carbon dioxide (CO2) footprint when burned, although it does result in nitrous oxide (NOX) emissions that require the use of NOX scrubbing technology. Recently, several major companies within the maritime sector have announced plans to utilize NH3 as a propulsion fuel for newly commissioned ships in conjunction with transporting NH3 by sea.2
This article contends that the current enthusiasm for NH3 as a H2 carrier stems from a limited awareness of new technologies designed for H2 transport and distribution. The economics and reliability of today’s fossil fuel economy rely on an exceptionally efficient network of specialized tankers and port facilities, dedicated pipelines and trucks. These midstream technologies evolved as the demand for petroleum products surged, and the initially acceptable technical approaches inevitably gave way to much more efficient technologies as the industry expanded. Likewise, the planned escalation of H2 production and increasing demand for green H2 from end users underscores the need for disruptive transportation innovations in pipeline technology and specially configured vehicles to address the unique requirements associated with H2.
In this regard, the H2 Clipper airship, which is specially designed for long-distance and trans-oceanic transport of low-cost liquid H2, is discussed.a This innovation enables the realization of the full disruptive value of H2 and is just one example of the seismic shifts underway in the global pursuit of a sustainable energy future. As new technologies continue to be developed, the technological and economic superiority of liquid H2 over green NH3 will cause the public to refocus on NH3’s essential, historical role in fertilizer production and meeting the growing global demand for food and food stocks.
Comparing H2, NH3 and other fuels. TABLE 1 provides a comparison of the properties of gaseous and cryogenic H2 with NH3, natural gas, liquefied natural gas (LNG) and other hydrocarbon fuels.3 H2 holds a considerable advantage when evaluating its lower heating value (LHV) per unit weight (FIG. 1). However, as noted above, difficulties in transport and distribution arise from H2’s extremely low density in gaseous form and, therefore, the volume necessary to convey an equivalent amount of energy (FIG. 2).
H2 is ESSENTIAL TO REVERSE GLOBAL WARMING
The global quest to reverse the perilous course of climate change hinges on the development of sustainable, low-carbon energy solutions. Congruent with this pursuit, H2—the most abundant element in the universe—has emerged as an essential component, possessing inherent qualities that make it indispensable in the battle against global warming.
Zero-emissions energy production. At the core of H2's value is its capacity to produce energy without generating harmful emissions. When H2 reacts with oxygen in proton exchange membrane (PEM) fuel cells, the result is the production of heat and energy with pure water as the only by-product. The fact that this process results in absolutely zero CO2 or NOX emissions aligns perfectly with the imperative to decarbonize planetary energy systems.
The electrification of everything. The concept of electrifying all facets of our lives forms the core of any strategy to mitigate climate change. However, some industries such as steel, cement, aviation and long-distance trucking pose unique challenges for grid-based or battery-electric power. In these cases, H2 provides an important solution. It can be harnessed through fuel cells to produce electricity for power, or, alternatively, combusted to generate the extreme temperatures required for cement production and steel manufacturing. H2's adaptability positions it as a key player in electrifying these “hard-to-abate” sectors.
Efficient energy storage. As energy is increasingly harnessed from intermittent clean sources like solar and wind, there is a growing need for efficient, low-cost and immediately dispatchable energy storage solutions. H2 uniquely provides such a solution. H2 offers long-term storage of energy, in effect representing a lower cost and longer-duration chemical battery. When energy demand surges or renewables wane, H2 can be reconverted into electricity either through fuel cells or H2-fueled turbines. This capability enhances grid stability and reduces the reliance on fossil fuels during periods of peak demand.
A global commitment. The significance of H2 in the fight against climate change is underscored by its inclusion in major legislative and policy initiatives worldwide—literally from Africa to Australia, Ireland to India, South America to the South Pacific, and the EU to the U.S. The U.S. government's Infrastructure Investment and Jobs Act (2021) and subsequent Inflation Reduction Act (2022) have allocated substantial funding and tax incentives to advance the H2 economy. In response to global energy security concerns, the EU has prioritized H2 in its REPowerEU plan and in designating Hy2Tech and Hy2Use initiatives as Important Projects of Common European Interest (IPCEI). Other nations and multinational corporations are also making substantial investments in H2, reinforcing its pivotal role in a sustainable future.
Abundance and universality. H2 is abundant, comprising approximately 73% of the universe’s mass—60% of the atoms in the human body are H2 atoms. Positioned at the top of the periodic table as the first element, H2 is the smallest and lightest atom, making it highly reactive with other elements. While H2 primarily exists in bonded form on Earth, recent discoveries of underground reserves of “white” or “gold” H2 in northeastern France have added to the potential of even lower cost, naturally occurring sources. However, liberating H2 from compounds, even from water, requires energy. An estimated 70% of the cost of producing a kilogram (kg) of H2 is the cost of electricity. This is why H2 production facilities are strategically placed in or near regions with abundant, and therefore low-cost, renewable energy sources.b
Like solar energy, specific regions achieve even lower costs. To ensure the competitiveness of green H2 against fossil fuels, H2 production must occur in regions with the lowest renewable electricity cost. However, as these examples illustrate, these regions are often considerable distances from major population centers and consumer markets, necessitating long-distance transportation to facilitate the transition to a green H2 economy.4
The dawn of green H2. Historically, H2 has been produced primarily through steam reformation of natural gas, which releases CO2—thus the label “gray H2” (or “blue H2” if this carbon is captured at the source). The emergence of green H2 represents a pivotal shift. Green H2 is generated through electrolysis, where an electrical current derived from renewable sources is used to split water into H2 and oxygen. The result is a 100% renewable, carbon-free energy carrier. The recent plummeting costs of renewable energy collection and electrolyzer technologies are making green H2 competitive, with prices now around $8/kg (before transportation and distribution costs), and estimated to drop even lower by 2030 as economies of scale are realized in large-size production facilities. This makes green H2 a compelling alternative to fossil fuels, with numerous green H2 plants poised to enter the market from Canada, Morocco, Scotland, Spain, Chile, Saudi Arabia, the UAE, the U.S. and more than 20 other countries.
The dawn of green NH3. The advent of green H2 has also opened the door to the era of green NH3. Whereas NH3 production traditionally has been associated with significant carbon emissions due to its reliance on H2 derived from fossil fuels, the availability of low-cost green H2 from renewable sources enables emissions-free NH3 production. The implications of green NH3 extend across multiple sectors. Agriculture, where NH3 serves as a vital component in fertilizer production, stands to benefit significantly. By transitioning to green NH3, the agriculture industry can reduce its carbon footprint, contributing to more sustainable and environmentally responsible food production.
Due to the eternal power of the sun and the abundance of H2, human civilization will never run out of sustainable, non-polluting energy. “H2 could prove to be the missing link to a climate-safe energy future […] with green H2 emerging as a game changer for achieving climate neutrality without compromising industrial growth and social development,” said Francesco La Camera, Director-General of the International Renewable Energy Agency.5
As we navigate the complexities of combating global warming, these attributes—coupled with emerging technologies and a growing global commitment—position H2 as a linchpin in our pursuit of a sustainable, carbon-free energy future. The following sections delve more deeply into the nuances of H2's potential and examine why green NH3, although valuable in specific applications, is not the best option as an energy carrier and/or alternative to pure H2 in the battle against climate change.
H2 TRANSPORTATION CHALLENGES
While H2 holds immense promise for energy storage and as a clean energy carrier, its widespread adoption faces significant challenges in the realm of transportation. The efficient and safe transport of H2 over long distances from where renewable energy costs are lowest, as well as the efficient and safe distribution of H2 from storage facilities to end users (i.e., industrial plants, fueling stations, other applications) is a critical aspect of realizing these benefits. This section delves into the complexities, obstacles and major challenges associated with H2 transportation.
Energy density and volume. One of the primary challenges of transporting H2 is its low energy density in gaseous form. As shown in TABLE 1, gaseous H2 is incredibly light; as a result, it occupies a relatively large volume compared to other fuels like natural gas and gasoline. To overcome this challenge, H2 is often compressed or liquefied, which reduces its volume for transport and storage. However, these processes require additional energy; and the need for high-pressure or cryogenic storage systems increases the complexity and cost of transportation infrastructure.c
Transport modes. H2 can be transported by various methods, including pipelines, trucks, ships and even airships, each with its unique set of challenges. Pipelines are the most efficient, but require right of way acquisition, substantial infrastructure development and a higher initial investment. Additionally, as Matthieu Landon of French President Macron’s Private Office has observed, once a pipeline terminus is constructed, it cannot be moved to adjust for changing distribution requirements over time. As natural gas pipes have shown, pipelines are also notorious for leaking—as the world’s smallest molecule, H2 will inevitably leak more than methane (CH4). Steel pipes are subject to corrosion and H2 embrittlement issues, and pipes made with plastic polymers have higher permeation rates. Gaseous H2 storage and transportation in trucks is exceedingly expensive and faces safety concerns, especially when dealing with high-pressure H2. Ships are a viable option for long-distance transport, but handling cryogenic liquid H2 presents its own challenges, such as boil-off during long voyages across warm ocean waters.
Safety considerations. Safety is a paramount concern in all energy discussions. As noted above, NH3 is so highly toxic that numerous shipping lines refuse to carry it, and “spills” can send people to the hospital or even kill them. Conversely, H2 is highly flammable and its properties can pose risks in the event of leaks or accidents. Ensuring the safe containment, handling and transport of H2 is a crucial aspect of any H2 distribution system. Implementing robust safety protocols, leak containment and detection systems, and emergency response plans is essential to mitigate these potential risks.
Infrastructure development. Building the necessary infrastructure for H2 transportation is a considerable undertaking. The development of pipelines, storage facilities, fueling stations and distribution networks requires significant investment and planning. Coordinating the expansion of this infrastructure with the growth of H2 production facilities and off-takers represents a “chicken or egg” challenge that is essential to creating a seamless supply chain.6 Flis and Deutsch assert, “The issue boils down to a lack of H2 infrastructure for connecting and balancing supply and demand, and an underlying failure to integrate industry mapping and energy infrastructure planning.”6
Energy efficiency and losses. During transportation and distribution, energy losses can occur, affecting the overall efficiency of the H2 supply chain. Compression, liquefaction and transportation processes can lead to energy losses, reducing the net energy benefits of H2. Minimizing such losses through technological advancements and optimized coordination is therefore crucial.
Geographic challenges. H2's promise lies in its ability to transport renewable energy from areas with abundant renewable resources to regions with high energy demand. However, this necessitates the development of an efficient, long-distance transportation infrastructure,7 which can be geographically challenging. Crossing varied terrains, traversing large bodies of water and ensuring reliability over extended distances are formidable tasks that require innovative solutions.
Transporting H2 over long distances from regions such as Chile or Australia will be more costly than producing it locally using local renewable energy resources in, for example, Germany. However, green H2 produced with electricity based on Germany’s domestic renewable electricity production cost will not compete favorably with fossil fuels. The unavoidable conclusion is that for H2 to compete favorably with fossil fuels requires a more efficient means of transport to open markets with very low renewable energy costs per kWh.7
Cryogenic transportation challenges. Transporting liquid H2 via ships necessitates extremely heavy storage tanks and massive supplemental cooling systems capable of holding H2 at –253°C (–423°F) for weeks at a time. If this is not done, the volume of liquid H2 will inevitably “boil off” during transit, thereby making the voyage uneconomic, as demonstrated by the first voyage of Kawasaki Heavy Industry’s Suiso Frontier ship in January 2023, which lost 37% of its cargo due to boil-off. A recent study calculated that transporting 160 tonnes (metric t) of liquid H2 from Qatar to Japan by ship would result in a loss of 13.77%, or 22 metric t of H2. In addition to the economic loss this represents, several prominent environmental groups have raised significant concerns about the leakage of H2 into the atmosphere.7
Terminal facility requirements. Beyond the substantial onboard infrastructure needed to transport H2 at cryogenic temperatures, even more extensive facilities are required at terminal sites. These facilities must not only accommodate the volume of liquid H2 to be off-loaded during each delivery, but they also must store a sufficient quantity of H2 for as much as a month or longer between individual shipments. This presents a considerable challenge, entailing significant investments to construct these highly specialized storage facilities, as well as substantial expenditures related to electricity and land acquisition. Moreover, when ships are used, these facilities must be situated at ports, which are already among the world's most congested and costly real estate due to the demands of routine shipping operations.
Economic viability and existing infrastructure. Such terminal facilities for H2 distribution must be built almost from scratch, and will require considerable scale-up vs. today’s largest facilities. Presently, the world’s largest cryogenic H2 storage tank, which is dedicated to storing H2 for rocket launches, is located at the U.S. National Aeronautics and Space Administration’s (NASA’s) Kennedy Space Center in Florida. This tank has a volume of 3,800 m3 and has been in operation since the 1960s. NASA is presently constructing a larger stationary tank, with a volume of almost 5,700 m3, that will be the world’s largest cryogenic H2 storage tank when commissioned. To support commercial operations via ship will require liquid H2 storage that is as much as 40 times larger!
Commercial bunkering facilities for cryogenic H2 are limited. Operating commercial service for extended durations while maintaining extremely low temperatures poses both logistical and cost challenges. Presently, there are only two small bunkering facilities for cryogenic H2 globally, situated in the ports of Hastings, Australia, and Kobe, Japan. These facilities were constructed to support Kawasaki's Suiso Frontier ship. Cryogenic tanks for commercial operations will require substantial electricity expenses to maintain the required low temperatures through pressure and cooling mechanisms. Establishing storage facilities this size poses substantial technical issues, high costs and land availability issues, especially at densely crowded ports.
H2 distribution over short distances with trucks is already part of the clean energy infrastructure, with estimated costs at $1.20/kg per 300 km.8 Long-term, pipelines provide an economical distribution system, such as the European Hydrogen Backbone (EHB), a network of existing and new H2 pipelines in the EU.9 A group of 33 energy infrastructure operators is actively developing the EHB, aiming to establish a network of H2 pipelines. This initiative involves an estimated investment range of €80 B–€143 B and proposes to construct a 53,000 km H2 pipeline network by 2040. Sponsors estimate that of this network, 60% will consist of retrofitted pipelines, and 40% will be new pipeline sections. According to assessments by the Hydrogen Council and McKinsey,8 the distribution cost for H2 gas through onshore retrofitted pipelines is projected to be $0.13/kg/1,000 km, while new pipelines are expected to incur a cost of $0.23/kg/1,000 km. Offshore pipelines are estimated to be 1.3–2.3 times more costly.9
H2 pipelines can transport ten times the energy at one-eighth the cost associated with long-distance electricity transmission and serve a dual purpose by distributing and storing energy. However, pipelines do not represent a feasible solution to cross thousands of kilometers of open ocean.
Addressing these complexities is crucial to realizing the full potential of H2 as a clean energy carrier and combating global warming effectively. Innovative technologies, infrastructure development and international collaboration surrounding promising alternatives are essential to establishing a robust and efficient H2 transportation network. The subsequent sections delve into emerging solutions and advancements that promise to overcome these hurdles and drive the H2 economy forward.
The case for NH3. NH3 is an inorganic chemical compound comprised of nitrogen (N2) and H2. Its historical significance dates to ancient times when farmers recognized its value as a fertilizer. Before the advent of modern synthesis methods in the early 1900s, NH3 was primarily sourced from niter deposits and guano on tropical islands. However, as demand grew, these natural reserves became insufficient to meet the world's needs. This scarcity drove scientific exploration into new avenues for NH3 production.
In a significant breakthrough, German chemists Fritz Haber and Carl Bosch developed the Haber–Bosch process, which converts atmospheric N2 into NH3 by a reaction with H2 using a metal catalyst under high temperature and pressure. This innovation revolutionized NH3 production and has allowed it to become a key global commodity.
Today, NH3 plays an important role in various industries worldwide. In 2021, global production of NH3 surpassed 235 MM metric t—approximately 70% of which was used to produce fertilizers, while the balance served as a raw material in the chemical and pharmaceutical, mining, textiles, plastics and refrigeration industries, and in diluted forms, for cleaning products.
As a result, NH3 has a well-established global infrastructure encompassing production, distribution and storage. Approximately 20 MM metric t of NH3 are traded annually, with more than 80% of this volume being transported by ships to 130 ports worldwide. Due to its attributes, remaining liquid at ambient temperature under its own vapor pressure and its high volumetric and gravimetric energy density, NH3 has gained attention as a potential organic carrier for H2. Proponents suggest that it could offer advantages in terms of known handling techniques and reduced costs compared to the transport of liquid H2.
The maritime industry has also recognized the potential of NH3. In November 2023, Maersk Shipping Lines announced plans to build a fleet of NH3-propelled, NH3 cargo carrying vessels;3 and Fortescue, one of the leading voices in the green revolution, has announced that it “will use green NH3 to decarbonize [the] company’s mining and shipping fleet.”10 However, as Fortescue Executive Chairman, Andrew Forrest, recently noted, “At the moment, the regulatory landscape does not allow for NH3 ships to operate.”11 Moreover, according to Wood Makenzie, it is important to note that despite these efforts, it will take decades for such shipbuilding commitments to meet a fraction of the burgeoning demand for green NH3 as a fertilizer, let alone as a source for green H2 once at the destination.12
To be continued… Part 2 of this article, which will appear in the July issue, will delve into the limitations and disadvantages of NH3 as a H2 carrier and an alternative energy source. The inherent risks associated with NH3 will be explored, including its high toxicity and safety hazards, as evidenced by recent accidents and spills. Additionally, some of the major environmental concerns related to NH3 usage will be examined, including NOX emissions, their impact on air quality and public health, and concerns these challenges present to the goals of a sustainable energy transition.
Part 2 will also address the significant economic and technical challenges involved in converting NH3 back to pure H2, especially for use in proton exchange membrane (PEM) fuel cells that are critical to the mobility sector (e.g., cars, buses, trains, heavy duty trucking, aircraft with electric engines). The inefficiencies of NH3 as a H2 transport medium will be explored, including the complexities and costs involved in multiple production, transportation and conversion cycles, and the challenges this presents to the overall economic viability of NH3 as an energy carrier.
Finally, in Part 2, an innovative solution will be introduced that promises to address these challenges more effectively than NH3. This alternative, which is poised to revolutionize the transport of H2 before the end of this decade, offers a glimpse into a more sustainable and efficient future for global energy systems. H2T
NOTES
LITERATURE CITED
Rinaldo S. Brutoco is a pioneering entrepreneur, author, executive and advocate for sustainable business practices and the cultivation of a globally just and sustainable economy. As the Founding President and CEO of the World Business Academy, Brutoco dedicates the Academy’s work to bridging the gap between business innovation and the advancement of global sustainability goals. Brutoco’s career spans various domains, including renewable energy, corporate responsibility and economic policies.
Brutoco's contributions to literature reflect his extensive expertise and commitment to these areas. In 2007, he co-authored Freedom from Mid-East Oil, a comprehensive assessment of the potential options to fossil fuels for simultaneously addressing global energy requirements, climate concerns and social justice issues. He has written extensively on the future role for H2 in addressing these issues, as well as the critical importance of more efficient methods of transporting H2 to enable this. In 2008, he filed for his first of 12 patents on methods for H2 transport, which led to the formation of H2 Clipper, Inc. in 2012. Through 2017, the firm was incubated by the World Business Academy.
A respected speaker and strategic advisor, Brutoco has co-founded a number of other non-profits, including JUST Capital, and counsels with global organizations aspiring to integrate sustainable practices into their operations. Through his writings and advocacy, Brutoco continues to be an influential figure in the movement towards a more sustainable and equitable global economy. The author can be reached at rinaldo@worldbusiness.org.
The World Business Academy is a 501(c)(3) non-profit think tank and action incubator focusing on the role and responsibility of business in relation to solving critical environmental and social challenges. The Academy’s focus on climate change and energy security results from an analysis of the most important threats to human survival and, thus, the survival of business. Formed in 1986, the organization’s 38-yr track record of leadership includes the publication of innovative books, articles, podcasts and videos discussing these topics and other issues of primary importance to society and the business community.