In a recipe for a net-zero future, hydrogen is sometimes considered the secret ingredient. A team of Carnegie Mellon researchers is moving beyond the hype to analyze the realities—and risks—of using hydrogen as part of our energy and manufacturing systems.“Many businesses and communities across the United States are putting their chips on hydrogen hubs,” says <a href="https://engineering.cmu.edu/directory/bios/karplus-valerie.html">Valerie Karplus</a>, a professor of <a href="https://www.cmu.edu/epp/people/faculty/valerie-karplus.html">engineering and public policy</a> and associate director of the <a href="https://www.cmu.edu/energy/" rel="noopener" target="_blank">Scott Institute for Energy Innovation</a>. “To realize their potential, hubs will need to navigate the tricky balance between maintaining the financial incentives necessary for early market development while upholding their commitment to reduce greenhouse gas emissions.”In the wake of $8 billion in federal funding that has helped regional stakeholders start up hydrogen hubs across the United States, Karplus and <a href="https://engineering.cmu.edu/directory/bios/morgan-m-granger.html">Granger Morgan</a> have summarized the two types of risks associated with early investment in hydrogen systems: economic, that maintaining hubs won’t be financially viable; and environmental, that hubs won’t reduce greenhouse gasses at a sufficient level, or that their use will exacerbate local pollution.<blockquote>To realize their potential, hubs will need to navigate the tricky balance between maintaining the financial incentives necessary for early market development while upholding their commitment to reduce greenhouse gas emissions.<cite>Valerie Karplus, Professor, Engineering and Public Policy</cite></blockquote>Karplus and Morgan, a professor of engineering and public policy, point out that in the effort to curb the effects of climate change, hydrogen offers many advantages, but it is not a panacea. A crucial step to making it a viable energy source is finding a production method that reduces greenhouse gas emissions and has increasingly favorable economics. They suggest that starting with hubs can address many of the economic risks, but regulation is required to address the environmental risks.“The bottom line is that hydrogen would be very useful if we could get it without environmental consequences,” said Morgan.Hydrogen can still indirectly contribute to greenhouse warming, putting particular pressure on making sure that transport, storage, and sequestration are handled properly.“Hydrogen is the lightest molecule, so it leaks very easily,” said Morgan. “Building a hydrogen system that doesn’t leak is really tough and takes a lot of attention.”As Morgan notes, hydrogen leaks are difficult to detect, and its presence extends the atmospheric lifetime of methane, a greenhouse gas that’s 40 times more potent than carbon dioxide.Morgan and Karplus’ research, which appears in the journal <a href="https://onlinelibrary.wiley.com/doi/10.1111/risa.17449" rel="noopener" target="_blank">Risk Analysis</a>, includes a set of design principles to help hydrogen hubs capitalize on their potential.Recommendations include streamlining of the regulatory requirements for hydrogen hubs, combined with efforts to engage with end users and address their concerns about the social and economic equity of new infrastructure appearing in communities.Beyond financial viability and climate mitigation, how hydrogen development affects workers and communities will shape its broader growth prospects. A hydrogen economy could provide a new source of employment in parts of the country that are already being hard hit by a decline in manufacturing or fossil energy production, given similarities in skills requirements. At the same time, a shift to hydrogen-based ironmaking processes for steel production could improve air quality and reduce associated negative health impacts to communities.

Hydrogen is sometimes considered a secret ingredient in the recipe for a net-zero future. As a team of Carnegie Mellon researchers points out, hydrogen offers many advantages, but it’s not a panacea.

Hubs: A step towards a hydrogen future?

Photovoltaics are set to meet over 40 percent of Switzerland’s electricity needs by 2050. But solar power isn’t always available when it’s needed: there’s too much of it in summer and too little in winter, when the sun shines less often and heat pumps are running at full tilt. According to the Swiss federal government’s Energy Strategy, Switzerland wants to close the winter electricity gap with a combination of imports, wind and hydropower as well as alpine solar plants and gas-fired power plants.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1725320869826-image.imageformat.carousel.940179852.jpg" style="width: 100%px;" class="fr-fic fr-dib">ETH researchers Samuel Heiniger (left, with a jar of iron ore) and Professor Wendelin Stark in front of the three iron reactors on ETH Zurich’s Hönggerberg campus. (Image: ETH Zurich)One way to minimise the need for imports and gas-fired power plants in winter is to produce hydrogen from cheap solar power in summer, which could then be converted into electricity in winter. However, hydrogen is highly flammable, extremely volatile and makes many materials brittle. Storing the gas from summer until winter calls for special pressurised containers and cooling technology. These require a lot of energy, while the many safety precautions that must be followed make building such storage facilities very expensive. What’s more, hydrogen tanks are never completely leak-proof, which harms the environment and adds to the costs.Now researchers at ETH Zurich led by Wendelin Stark, Professor of Functional Materials at the Department of Chemistry and Applied Biosciences, have developed a new technology for the seasonal storage of hydrogen that is much safer and cheaper than existing solutions. The researchers are using a well-known technology and the fourth most abundant element on Earth: iron.<h2>Chemical storage</h2>To store hydrogen better, Stark and his team are relying on the steam-iron process, which has been understood since the 19th century. If there is a surplus of solar power available in the summer months, it can be used to split water to produce hydrogen. This hydrogen is then fed into a stainless steel reactor filled with natural iron ore at 400 degrees Celsius. There, the hydrogen extracts the oxygen from the iron ore – which in chemical terms is simply iron oxide – resulting in elemental iron and water.“This chemical process is similar to charging a battery. &nbsp;It means that the energy in the hydrogen can be stored as iron and water for long periods with almost no losses,” Stark says. When the energy is needed again in winter, the researchers reverse the process: they feed hot steam into the reactor to turn the iron and water back into iron oxide and hydrogen. The hydrogen can then be converted into electricity or heat in a gas turbine or fuel cell. To keep the energy required for the discharging process to a minimum, the steam is generated using waste heat from the discharging reaction.<a target="_blank"></a><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1725320890968-image.imageformat.1286.408338324.png" style="width: 100%px;" class="fr-fic fr-dib">The charging and discharging process for the storage technology. (Visualisations: ETH Zurich)<h2 id="isPasted">Cheap iron ore meets expensive hydrogen</h2>“The big advantage of this technology is that the raw material, iron ore, is easy to procure in large quantities. Plus it doesn’t even need processing before we put it in the reactor,” Stark says. Moreover, the researchers assume that large iron ore storage facilities could be built worldwide without substantially influencing the global market price of iron.The reactor in which the reaction takes place doesn’t have to fulfil any special safety requirements either. It consists of stainless steel walls just 6 millimetres thick. The reaction takes place at normal pressure and the storage capacity increases with each cycle. Once filled with iron oxide, the reactor can be reused for any number of storage cycles without having to replace its contents. Another advantage of the technology is that the researchers can easily expand the storage capacity. It’s simply a case of building bigger reactors and filling them with more iron ore. All these advantages make this storage technology an estimated ten times cheaper than existing methods.However, there’s also a downside to using hydrogen: its production and conversion are inefficient compared to other sources of energy, as up to 60 percent of its energy is lost in the process. This means that as a storage medium, hydrogen is most attractive when sufficient wind or solar power is available and other options are off the table. That is especially the case with industrial processes that can’t be electrified.<h2>Pilot plant on the Hönggerberg campus</h2>The researchers have demonstrated the technical feasibility of their storage technology using a pilot plant on the Hönggerberg campus. This consists of three stainless steel reactors with a capacity of 1.4 cubic metres, each of which the researchers have filled with 2–3 tonnes of untreated iron ore available on the market.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1725320913294-image.imageformat.1286.858633795.jpg" style="width: 100%px;" class="fr-fic fr-dib">This 1.4-cubic-metre stainless steel reactor at the Hönggerberg campus holds 2–3 tonnes of untreated iron ore. (Image: ETH Zurich)“The pilot plant can store around 10 megawatt hours of hydrogen over long periods. Depending on how you convert the hydrogen into electricity, that’ll give you somewhere between 4 and 6 megawatt hours of power,” explains Samuel Heiniger, a doctoral student in Stark’s research group. This corresponds to the electricity demand from three to five Swiss single-family homes in the winter months. At present, the system is still running on electricity from the grid and not on the solar power generated on the Hönggerberg campus.This is soon set to change: the researchers want to expand the system such that by 2026, the ETH Hönggerberg campus can meet one-fifth of its winter electricity requirements using its own solar power from the summer. This would require reactors with a volume of 2,000 cubic metres, which could store around 4 gigawatt hours (GWh) of green hydrogen. Once converted into electricity, the stored hydrogen would supply around 2 GWh of power. “This plant could replace a small reservoir in the Alps as a seasonal energy storage facility. To put that in perspective, it equates to around one-tenth of the capacity of the Nant de Drance pumped storage power plant,” Stark says. In addition, the discharging process would generate 2 GWh of heat, which the researchers want to integrate into the campus’s heating system.<h2 id="isPasted">Good scalability</h2>But could this technology be harnessed to provide seasonal energy storage for Switzerland as a whole? The researchers have made some initial calculations: providing Switzerland with around 10 terawatt hours (TWh) of electricity from seasonal hydrogen storage systems every year in the future – which would admittedly be a lot – would require some 15–20 TWh of green hydrogen and roughly 10,000,000 cubic metres of iron ore. “That’s about 2 percent of what Australia, the largest producer of iron ore, mines every year,” Stark says. By way of comparison, in its <a target="_blank">Energy Perspectives 2050+</a>, the Swiss Federal Office of Energy anticipates total electricity consumption of around 84 TWh in 2050.If reactors were built that could store around 1 GWh of electricity each, they would have a volume of roughly 1,000 cubic metres. This calls for around 100 square metres of building land. Switzerland would have to build some 10,000 of these storage systems to obtain 10 TWh of electricity in winter, which corresponds to an area of around 1 square metre per inhabitant.<hr><h2 id="isPasted">Coalition for Green Energy and Storage (CGES)</h2>This project is part of the <a href="https://ethz.ch/en/news-and-events/eth-news/news/2023/06/eth-zurich-and-epfl-launch-a-green-energy-coalition.html" target="_blank">Coalition for Green Energy and Storage</a>, which ETH Zurich launched in 2023 together with EPFL, PSI and Empa and is driving forward together with industrial partners - including major Swiss energy suppliers and authorities. The coalition has set itself the goal of rapidly bringing innovative technologies for the production and storage of carbon-neutral gases and fuels and for CO2 capture to market maturity. As part of CGES, larger pilot plants (‘catapults’) are to be built to test these technologies and make important contributions to the climate-neutral transformation of the energy system and security of supply. The next step will be to establish an association that will network interested stakeholders, provide them with scientific support and guidance and facilitate the implementation of projects.<h2 id="isPasted">Reference</h2>Literature: Heiniger, SP; Fan Z; Lustenberger UB, Stark WJ: Safe seasonal energy and hydrogen storage in a 1 : 10 single-household-sized pilot reactor based on the steam-iron process. Sustainable Energy &amp; Fuels 2024, 8 (1), 125-132. <a href="https://doi.org/10.1039/D3SE01228J" target="_blank">https://doi.org/10.1039/D3SE01228J</a>

Researchers at ETH Zurich are using iron to store hydrogen safely and for long periods. In the future, this technology could be used for seasonal energy storage.

Iron as an inexpensive storage medium for hydrogen

In this episode, we discuss how MIT researchers cracked the code for affordable, sustainable, and scalable hydrogen production using commonly found materials and a secret alloy!

Podcast: Turning Scrap Soda Cans & Coffee To Sustainable Car Fuel

This article was discussed in our <a href="https://www.wevolver.com/profile/the.next.byte" rel="noopener noreferrer" target="_blank">Next Byte podcast</a>.&nbsp;<iframe height="200px" width="100%" frameborder="no" scrolling="no" seamless="" src="https://player.simplecast.com/60fd7e2c-4154-4104-8c57-a3377abb0ca4?dark=false" class="fr-draggable" data-gtm-yt-inspected-23="true" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true"></iframe> The full article will continue below.<hr>A sustainable source for clean energy may lie in old soda cans and seawater.MIT engineers have found that when the aluminum in soda cans is exposed in its pure form and mixed with seawater, the solution bubbles up and naturally produces hydrogen — a gas that can be subsequently used to power an engine or fuel cell without generating carbon emissions. What’s more, this simple reaction can be sped up by adding a common stimulant: caffeine.In a study <a href="https://www.cell.com/cell-reports-physical-science/fulltext/S2666-3864(24)00399-0" target="_blank">appearing today in the journal Cell Reports Physical Science</a>, the researchers show they can produce hydrogen gas by dropping pretreated, pebble-sized aluminum pellets into a beaker of filtered seawater. The aluminum is pretreated with a rare-metal alloy that effectively scrubs aluminum into a pure form that can react with seawater to generate hydrogen. The salt ions in the seawater can in turn attract and recover the alloy, which can be reused to generate more hydrogen, in a sustainable cycle.<iframe width="640" height="360" src="https://www.youtube.com/embed/QIowXoHPeFk?&amp;wmode=opaque&amp;enablejsapi=1&amp;origin=https://www.wevolver.com" frameborder="0" allowfullscreen="" class="fr-draggable" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true" data-gtm-yt-inspected-23="true" id="21089365" title="A sustainable way to generate hydrogen fuel">&nbsp;&nbsp;</iframe>A pebble-sized pellet of aluminum, dropped into a beaker of filtered seawater, produces hydrogen gas that bubbles up and out of the container within a few minutes. MIT engineers are optimizing this simple chemical reaction as an efficient and sustainable way to generate hydrogen fuel, which they envision can be used to power an engine or fuel cell aboard marine vessels and underwater vehicles.The team found that this reaction between aluminum and seawater successfully produces hydrogen gas, though slowly. On a lark, they tossed into the mix some coffee grounds and found, to their surprise, that the reaction picked up its pace.In the end, the team discovered that a low concentration of imidazole — an active ingredient in caffeine — is enough to significantly speed up the reaction, producing the same amount of hydrogen in just five minutes, compared to two hours without the added stimulant.The researchers are developing a small reactor that could run on a marine vessel or underwater vehicle. The vessel would hold a supply of aluminum pellets (recycled from old soda cans and other aluminum products), along with a small amount of gallium-indium and caffeine. These ingredients could be periodically funneled into the reactor, along with some of the surrounding seawater, to produce hydrogen on demand. The hydrogen could then fuel an onboard engine to drive a motor or generate electricity to power the ship.“This is very interesting for maritime applications like boats or underwater vehicles because you wouldn’t have to carry around seawater — it’s readily available,” says study lead author Aly Kombargi, a PhD student in MIT’s Department of Mechanical Engineering. “We also don’t have to carry a tank of hydrogen. Instead, we would transport aluminum as the ‘fuel,’ and just add water to produce the hydrogen that we need.”The study’s co-authors include Enoch Ellis, an undergraduate in chemical engineering; Peter Godart PhD ’21, who has founded a company to recycle aluminum as a source of hydrogen fuel; and Douglas Hart, MIT professor of mechanical engineering.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzIxOTUzNzIxNzYwLU1JVC1TZWF3YXRlci1IeWRyb2dlbi0wMi1wcmVzcy5qcGciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 100%px;" class="fr-fic fr-dib">A researcher demonstrates “activating” aluminum by dipping an aluminum pellet in a mixture of gallium-indium. Photo: Tony Pulsone<h2>Shields up</h2>The MIT team, led by Hart, is developing efficient and sustainable methods to produce hydrogen gas, which is seen as a “green” energy source that could power engines and fuel cells without generating climate-warming emissions.One drawback to fueling vehicles with hydrogen is that some designs would require the gas to be carried onboard like traditional gasoline in a tank — a risky setup, given hydrogen’s volatile potential. Hart and his team have instead looked for ways to power vehicles with hydrogen without having to constantly transport the gas itself.They found a possible workaround in aluminum — a naturally abundant and stable material that, when in contact with water, undergoes a straightforward chemical reaction that generates hydrogen and heat.The reaction, however, comes with a sort of Catch-22: While aluminum can generate hydrogen when it mixes with water, it can only do so in a pure, exposed state. The instant aluminum meets with oxygen, such as in air, the surface immediately forms a thin, shield-like layer of oxide that prevents further reactions. This barrier is the reason hydrogen doesn’t immediately bubble up when you drop a soda can in water.In previous work, using fresh water, the team found they could pierce aluminum’s shield&nbsp;and keep the reaction with water going by pretreating the aluminum with a small amount of rare metal alloy made from a specific concentration of gallium and indium. The alloy serves as an “activator,” scrubbing away any oxide buildup and creating a pure aluminum surface that is free to react with water. When they ran the reaction in fresh, de-ionized water, they found that one pretreated pellet of aluminum produced 400 milliliters of hydrogen in just five minutes. They estimate that just 1 gram of pellets would generate 1.3 liters of hydrogen in the same amount of time.But to further scale up the system would require a significant supply of gallium indium, which is relatively expensive and rare.“For this idea&nbsp;to be cost-effective and sustainable, we had to work on recovering this alloy postreaction,” Kombargi says.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzIxOTUzNzQ3MTk2LU1JVC1TZWF3YXRlci1IeWRyb2dlbi0wMy1wcmVzcy5qcGciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 100%px;" class="fr-fic fr-dib">Aly Kombargi holds a jar of aluminum pellets as they start to react in seawater. Photo: Tony Pulsone<h2>By the sea</h2>In the team’s new work, they found they could retrieve and reuse gallium indium using a solution of ions. The ions — atoms or molecules with an electrical charge — protect the metal alloy from reacting with water and help it to precipitate into a form that can be scooped out and reused. &nbsp;&nbsp;“Lucky for us, seawater is an ionic solution that is very cheap and available,” says Kombargi, who tested the idea with seawater from a nearby beach. “I literally went to Revere Beach with a friend and we grabbed our bottles and filled them, and then I just filtered out algae and sand, added aluminum to it, and it worked with the same consistent results.”He found that hydrogen indeed bubbled up when he added aluminum to a beaker of filtered seawater. And he was able to scoop out the gallium indium afterward. But the reaction happened much more slowly than it did in fresh water. It turns out that the ions in seawater act to shield gallium indium, such that it can coalesce and be recovered after the reaction. But the ions have a similar effect on aluminum, building up a barrier that slows its reaction with water.As they looked for ways to speed up the reaction in seawater, the researchers tried out various and unconventional ingredients.“We were just playing around with things in the kitchen, and found that when we&nbsp;added coffee grounds into seawater and dropped aluminum pellets in, the reaction was quite fast compared to just seawater,” Kombargi says.To see what might explain the speedup, the team reached out to colleagues in MIT’s chemistry department, who suggested they try imidazole — an active ingredient in caffeine, which happens to have a molecular structure that can pierce through aluminum (allowing the material to continue reacting with water), while leaving gallium indium’s ionic shield intact.“That was our big win,” Kombargi says. “We had everything we wanted: recovering the gallium indium, plus the fast and efficient reaction.”The researchers believe they have the essential ingredients to run a sustainable hydrogen reactor. They plan to test it first in marine and underwater vehicles. They’ve calculated that such a reactor, holding about 40 pounds of aluminum pellets, could power a small underwater glider for about 30 days by pumping in surrounding seawater and generating hydrogen to power a motor.“We’re showing a new way to produce hydrogen fuel, without carrying hydrogen but carrying aluminum as the ‘fuel,’” Kombargi says. “The next part is to figure out how to use this for trucks, trains, and maybe airplanes. Perhaps, instead of having to carry water as well, we could extract water from the ambient humidity to produce hydrogen. That’s down the line.”

MIT engineers Aly Kombargi (left) and Niko Tsakiris (right) work on a new hydrogen reactor, designed to produce hydrogen gas by mixing aluminum pellets with seawater. Photo: Tony Pulsone

MIT engineers have developed a fast and sustainable method for producing hydrogen fuel using aluminum, saltwater, and coffee grounds.

A recipe for zero-emissions fuel: Soda cans, seawater, and caffeine

There’s a role for sustainably produced hydrogen in the energy transition, and not only as an energy storage medium or as fuel for lorries. In industry, it could be used wherever hydrogen is already needed today: for example, in the production of ammonia. Worldwide, 180 million tonnes of ammonia are produced every year, mainly for the fertiliser industry. The necessary hydrogen is currently obtained from natural gas, which results in high greenhouse gas emissions and a reliance on gas-exporting countries. Using green hydrogen as a clean alternative would bring the world closer to climate targets and reduce dependency. Green hydrogen is produced using sustainable electricity via a process called electrolysis.In a study looking at the European ammonia industry, researchers from the Hong Kong University of Science and Technology (HKUST) and ETH Zurich have now calculated the conditions under which it would be worthwhile to switch ammonia production to green or almost green hydrogen.<h2>Already economically viable in Spain and Norway</h2>Two results stand out. First, in some European countries such as Norway, Spain, Hungary or Poland, ammonia production from green or almost green hydrogen would already make economic sense today. In these countries, generating sustainable electricity from solar or wind energy is particularly cost-effective. This is thanks to these countries’ favourable geographical conditions, as well as state subsidies or generally low electricity costs. The latter means that, in the absence of sunshine or wind, hydrogen production could fall back on cheap power from the grid. As a result, producers here could do without expensive storage solutions for sustainable electricity.Second, even electricity that isn’t completely fossil-free will still have a thoroughly positive climate impact. According to the study, hydrogen from electrolysis makes sense even if some of the power used isn’t from renewable sources. This gives producers the freedom to switch to electricity from the grid, some of which comes from fossil sources, whenever the sun or wind is in short supply.<h2>One kilogramme of CO2 would be fine for the climate</h2>The study’s lead author is Stefano Mingolla, a doctoral student at HKUST. He worked for six months in the group led by Giovanni Sansavini, Professor at the Department of Mechanical and Process Engineering at ETH Zurich. “If you use almost green hydrogen to produce ammonia, you can achieve a lot very quickly – it’s low-hanging fruit,” Sansavini says. “This is in contrast to other applications, where hydrogen serves merely as energy storage and requires conversion from one form of energy to another. In ammonia production, hydrogen is used directly as a raw material, eliminating the need for inefficient conversions.”<a target="_blank"></a><blockquote>“It’s important to adjust ambitions accordingly.” -&nbsp;<cite>Giovanni Sansavini</cite></blockquote><a target="_blank"></a>Calculations by Mingolla and his colleagues show that greenhouse gas emissions from ammonia production could be reduced by 95 percent compared to today if the hydrogen used were produced in a way that releases no more than one kilogramme of CO2 per kilogramme of hydrogen. The electricity required for this would have to be significantly greener than the current mix in Germany, Poland and the Netherlands. These three countries are the largest ammonia producers in Europe. For comparison: one kilogramme of hydrogen produced using the Swiss electricity mix would lead to emissions of 1.7 kilogrammes of CO2; the figure using the current electricity mix in Germany would be 18 kilogrammes of CO2, in the Netherlands 16 kilogrammes and in Poland 33 kilogrammes.Decarbonising hydrogen production completely, rather than just by 95 percent, would be prohibitively expensive. The last 5 percent of decarbonisation is the most complex and costly; it would almost double the overall price tag. “It’s important to adjust ambitions accordingly,” Sansavini says. “It would be counterproductive to aim for complete decarbonisation, as the excessive costs could slow down the energy transition.”<h2>New solar and wind parks for hydrogen production</h2>However, Sansavini emphasises that hydrogen won’t be produced on a large scale using electricity from the grid since, in many cases, both local power generation and cross-border grid transmission capacity are inadequate.A more likely scenario is for new solar or wind farms to be built directly next to existing ammonia plants. However, this requires large areas of land. As the study shows, the more a given region enjoys favourable geographical conditions for generating electricity from solar or wind energy, the less land is needed. Southern Europe and areas along the Atlantic coast have an advantage here. “Because the amount of land required is so large, we need to think primarily about combined land use – for instance, a wind or solar farm where agriculture can be practised at the same time,” Sansavini says.Green hydrogen might already be competitive in Norway, Spain, Hungary and Poland, but on average across Europe, producing it is significantly more expensive than extracting hydrogen from natural gas. “For green hydrogen to become competitive everywhere, further investment in research and development is needed, as are economic incentives,” Sansavini says. What exactly is meant by “green” hydrogen is also currently being discussed in the EU. “We need to balance the costs and the environmental impact. Any definition should permit green hydrogen to contain some residual fossil energy,” Sansavini explains. Using the example of ammonia production, the research team has now calculated a recommendation for this residual proportion: up to one kilogramme of CO2 emissions per kilogramme of hydrogen would be acceptable and sensible.<hr><h2 id="isPasted">Reference</h2>Mingolla S, Gabrielli P, Manzotti A, Robson MJ, Rouwenhorst K, Ciucci F, Sansavini G, Klemun MM, Lu Z: Effects of emissions caps on the costs and feasibility of low-carbon hydrogen in the European ammonia industry, Nature Communications, 4 May 2024, doi:&nbsp;<a href="https://www.nature.com/articles/s41467-024-48145-z" target="_blank">external page10.1038/s41467-024-48145-z</a>

In April 2024, the electricity company Axpo opened a hydrogen production facility adjacent to a hydropower plant in the Swiss canton of Graubünden. A large-scale ammonia plant would require a much bigger facility. (Photograph: Keystone-SDA / Gian Ehrenzeller)

Whether sustainably produced hydrogen needs to be 100 percent green is currently under debate. Using the production of ammonia and artificial fertiliser as examples, researchers have calculated that "nearly sustainable" hydrogen would be better in the end.

Light green hydrogen will do

In this episode, we discuss a breakthrough from an EPFL researcher which promises to finally make hydrogen a feasible source of energy by extracting it efficiently from ammonia. 

Podcast: How Hydrogen Will Replace Batteries

This article was discussed in our <a href="https://www.wevolver.com/profile/the.next.byte" rel="noopener noreferrer" target="_blank">Next Byte podcast</a>.&nbsp;<iframe height="200px" width="100%" frameborder="no" scrolling="no" seamless="" src="https://player.simplecast.com/d344b4d7-c914-4440-94aa-c7bf46961d53?dark=false" class="fr-draggable" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true"></iframe> The full article will continue below.<hr>Without hydrogen, Kevin Turani-I-Belloto surely wouldn’t have chosen hydrogen storage as the topic for his PhD thesis, and he probably wouldn’t even have come to EPFL. But today, it’s hydrogen’s cousin ammonia – NH3, a combination of hydrogen and nitrogen – that’s keeping him busy. Turani-I-Belloto is an associate researcher at EPFL’s <a href="https://www.epfl.ch/labs/gcb/" target="_blank">Catalysis for Biofuels research group</a> headed by Prof. Oliver Kröcher, and he’s developed a catalyst that can break down ammonia at a lower cost than existing methods, and without the need for rare-earth metals. Last fall he received an Ignition grant from EPFL’s Vice Presidency for Innovation and an Enable grant from EPFL’s Technology Transfer Office to help him build a prototype. And now, he’s been selected for a Bridge Proof of Concept grant, offered through a joint initiative by the Swiss National Science Foundation and Innosuisse.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEwMTM1NDExMDk1LTc3MzR4NTE1OS5qcGciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 100%px;" class="fr-fic fr-dib">© 2024 EPFL/Alain Herzog - CC-BY-SA 4.0Hydrogen holds just as much promise for storing the surplus power from renewable energy as for being used as fuel. It’s the smallest molecule in the universe and can escape through even the tiniest hole. Owing to its ultra-low density, it has to be stored at a pressure of 350 or 700 bars – depending on the standard – for use in gas form, or at a temperature of –252°C for use in liquid form. Distribution networks for hydrogen remain scarce and, therefore, expensive. Operators of ships and aircraft – vehicles for which electric batteries are not yet viable – are placing their bets on hydrogen or synthetic fuels made from hydrogen, although the production of these compounds isn’t very energy efficient.<h2>A secret formula</h2>That’s where Turani-I-Belloto’s new method comes in. He proposes using ammonia to transport hydrogen. “Today, half of the hydrogen that’s produced goes to the manufacture of ammonia, which in turn is used as the main ingredient in fertilizer,” he says. Ammonia is a colorless gas but not odorless, meaning leaks can be detected fairly easily. It can be liquified at a relatively low pressure (8.5 bars) and a reasonable temperature (–33°C), making it a good candidate for transport. Liquid ammonia also has a higher energy density than liquid hydrogen. “What’s more, distribution networks for ammonia are already well-developed around the world,” says Turani-I-Belloto. “Hence my idea for using it to transport hydrogen.”“What I want to do is leverage the benefits of each gas: ammonia for transport and hydrogen for energy, producing it from ammonia right where it’s needed” says Turani-I-Belloto. “That’ll make it possible to meet demand for clean energy, both for cargo vehicles and in an array of other industries.” Turning ammonia into hydrogen requires the use of a catalyst. “Catalyzing agents do exist, but they’re either not effective enough or they’re too expensive, like ruthenium, an extremely rare metal. My system delivers high yields, uses abundant raw materials and cuts the catalyst cost by a factor of over 200.”Funding agencies clearly see potential in Turani-I-Belloto’s technology, although he’s keeping the details of his process under wraps. “It’s my magic formula,” he says. So we won’t get a peek into the black box. However, his compact demonstrator is now set up in the research group’s laboratory, and it has demonstrated the potential of his innovative catalyst. He’s filed for a patent for his invention.“If we’re successful in using ammonia to store hydrogen, that will unlock an entire value chain,” says Turani-I-Belloto, who’s working tirelessly to reach that goal.

Kevin Turani-I-Belloto has developed a low-cost method for breaking down ammonia to produce hydrogen. He’s just been awarded a Bridge grant to develop a proof of concept for his technology.

Getting hydrogen out of ammonia

The role of renewable energy and hydrogen as an alternative energy source is of interest to many modern industries. Hydrogen is cleaner, more efficient and more sustainable than fossil fuels and has the potential to replace them. A significant contribution to the fight against climate change is therefore within reach. However, there are technical challenges to overcome in the production, transport and storage of the medium.The quest for sustainability is leading companies such as Haver &amp; Boecker to focus their strategies on renewable energy and green hydrogen. Although abundant, hydrogen is bound in nature and requires efficient processes to release it. This is where research comes in to develop and optimise such processes.<h3>Technological leader in hydrogen technology</h3>Haver &amp; Boecker is actively involved in the development of solutions for hydrogen technology. A key element is wire mesh, which plays a crucial role in both the production and application of hydrogen. The company is continuously working to meet the challenges of handling the medium.<h3>Example of PEM fuel cells</h3>High-purity hydrogen is critical because impurities such as carbon monoxide, sulphur compounds or ammonia can damage the platinum catalysts and reduce their efficiency. Even small amounts of impurities can cause chemical reactions that attack the fuel cell membrane, resulting in reduced performance or complete system failure. Filtering the hydrogen to a high level of purity is therefore essential to ensure durability, reliability and maximum performance.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1706021652692-Branche-Wasserstoff-Brennstoffzelle-1366x768.jpg" style="width: 300px;" class="fr-fic fr-dib">A stack in a PEM fuel cell system is the central element in which electricity is generated by the electrochemical reaction of hydrogen and oxygen, with water as the only by-product. Source:&nbsp;<a href="https://www.referenzfabrik.de/referenzfabrik-start.html" target="_blank" id="isPasted">Referenzfabrik H2</a>Haver &amp; Boecker woven wire cloth removes contaminants by filtering out not only chemical particles but also micro-organisms. This ensures a high level of hydrogen purity, which is essential for optimum performance and longevity of PEM fuel cell systems.<h3 id="isPasted">Other applications</h3>Wire mesh already plays a vital role in the manufacturing process. It is used in various electrolysis processes such as alkaline, PEM and high-temperature electrolysis. As a component of anodes and cathodes, it makes a significant contribution to efficient and rapid hydrogen production. The following key factors should be highlighted:<ol><li>The wire mesh provides a larger surface area for electrochemical reactions. This is particularly important in water electrolysis where hydrogen is produced at the cathode. A larger active surface area results in more efficient and faster hydrogen production.</li><li>The electrical conductivity in the electrodes is improved. This is essential to reduce the resistance in the electrolysis system, which increases the efficiency of hydrogen production.</li><li>The reactants (such as water) are evenly distributed over the electrode. This ensures more efficient use of the electrolyte and prevents local hotspots that could reduce performance.</li><li>The wire mesh provides structural support and durability for the electrodes, which is particularly important to ensure the long-term stability and reliability of the electrolysis system.</li></ol>The mesh is particularly resistant to the chemical and physical properties of hydrogen, such as its considerable reactivity and the high pressures encountered during transport.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1706021736321-Explosionsschutz-Presslinge-1366x768.jpg" style="width: 300px;" class="fr-fic fr-dib">Wire mesh in heaters provides protection against flashback and optimises heat distribution, while its properties such as temperature and corrosion resistance and pore size accuracy are important for the efficient and environmentally friendly use of hydrogen.Another advantage is its customisability: the product can be manufactured individually according to specific requirements and specifications, providing a tailor-made solution for different applications. This flexibility makes it possible to configure wire mesh for a wide range of applications, whether for filtration, separation or reinforcement, to meet specific handling and transport requirements.<h3>A look at the future</h3>Haver &amp; Boecker is constantly working to improve the efficiency and safety of hydrogen handling and to further optimise its proven technology. This includes the development of heavy-duty wire meshes for various applications, from electromobility to the chemical industry. Through continuous innovation and collaboration with other companies and institutes, the company is making a significant contribution to the energy transition.

The role of renewable energy and hydrogen as an alternative energy source is of interest to many modern industries. Hydrogen is cleaner, more efficient and more sustainable than fossil fuels and has the potential to replace them. 

Wire mesh for efficient handling of hydrogen

MIT’s Electric Vehicle Team, which has a long record of building and racing innovative electric vehicles, including cars and motorcycles, in international professional-level competitions, is trying something very different this year: The team is building a hydrogen-powered electric motorcycle, using a fuel cell system, as a testbed for new hydrogen-based transportation.The motorcycle successfully underwent its first full test-track demonstration in October. It is designed as an open-source platform that should make it possible to swap out and test a variety of different components, and for others to try their own versions based on plans the team is making freely available online.Aditya Mehrotra, who is spearheading the project, is a graduate student working with mechanical engineering professor Alex Slocum, the Walter M. May &nbsp;and A. Hazel May Chair in Emerging Technologies. Mehrotra was studying energy systems and happened to also really like motorcycles, he says, “so we came up with the idea of a hydrogen-powered bike. We did an evaluation study, and we thought that this could actually work. We [decided to] try to build it.”Team members say that while battery-powered cars are a boon for the environment, they still face limitations in range and have issues associated with the mining of lithium and resulting emissions. So, the team was interested in exploring hydrogen-powered vehicles as a clean alternative, allowing for vehicles that could be quickly refilled just like gasoline-powered vehicles.Unlike past projects by the team, which has been part of MIT since 2005, this vehicle will not be entering races or competitions but will be presented at a variety of conferences. The team, consisting of about a dozen students, has been working on building the prototype since January 2023. In October they presented the bike at the Hydrogen Americas Summit, and in May they will travel to the Netherlands to present it at the World Hydrogen Summit. In addition to the two hydrogen summits, the team plans to show its bike at the Consumer Electronics Show in Las Vegas this month.“We’re hoping to use this project as a chance to start conversations around ‘small hydrogen’ systems that could increase demand, which could lead to the development of more infrastructure," Mehrotra says. "We hope the project can help find new and creative applications for hydrogen.” In addition to these demonstrations and the online information the team will provide, he adds, they are also working toward publishing papers in academic journals describing their project and lessons learned from it, in hopes of making “an impact on the energy industry.”<iframe width="640" height="360" src="https://www.youtube.com/embed/yUj7Hy7yq-0?&amp;wmode=opaque&amp;rel=0&amp;enablejsapi=1&amp;origin=https://www.wevolver.com" frameborder="0" allowfullscreen="" class="fr-draggable" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true">&nbsp;&nbsp;</iframe>For the love of speed: Building a hydrogen-powered motorcycleThe motorcycle took shape over the course of the year piece by piece. “We got a couple of industry sponsors to donate components like the fuel cell and a lot of the major components of the system,” he says. They also received support from the MIT Energy Initiative, the departments of Mechanical Engineering and Electrical Engineering and Computer Science, and the MIT Edgerton Center.Initial tests were conducted on a dynamometer, a kind of instrumented treadmill Mehrotra describes as “basically a mock road.” The vehicle used battery power during its development, until the fuel cell, provided by South Korean company Doosan, could be delivered and installed. The space the group has used to design and build the prototype, the home of the Electric Vehicle Team, is in MIT’s Building N51 and is well set up to do detailed testing of each of the bike’s components as it is developed and integrated.Elizabeth Brennan, a senior in mechanical engineering, says she joined the team in January 2023 because she wanted to gain more electrical engineering experience, “and I really fell in love with it.” She says group members “really care and are very excited to be here and work on this bike and believe in the project.”Brennan, who is the team’s safety lead, has been learning about the safe handling methods required for the bike’s hydrogen fuel, including the special tanks and connectors needed. The team initially used a commercially available electric motor for the prototype but is now working on an improved version, designed from scratch, she says, “which gives us a lot more flexibility.”As part of the project, team members are developing a kind of textbook describing what they did and how they carried out each step in the process of designing and fabricating this hydrogen electric fuel-cell bike. No such motorcycle yet exists as a commercial product, though a few prototypes have been built.That kind of guidebook to the process “just doesn’t exist,” Brennan says. She adds that “a lot of the technology development for hydrogen is either done in simulation or is still in the prototype stages, because developing it is expensive, and it’s difficult to test these kinds of systems.” One of the team’s goals for the project is to make everything available as an open-source design, and “we want to provide this bike as a platform for researchers and for education, where researchers can test ideas in both space- and funding-constrained environments.”Unlike a design built as a commercial product, Mehrotra says, “our vehicle is fully designed for research, so you can swap components in and out, and get real hardware data on how good your designs are.” That can help people work on implementing their new design ideas and help push the industry forward, he says.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1705050467068-I_102223-AG-MIT-Motorcycle-0027.jpg" style="width: 300px;" class="fr-fic fr-dib">Using an on-board logging computer, Electric Vehicle Team members (from left to right:) Anand John, Rachel Mohammed, and Aditya Mehrotra check data on the bike’s performance, battery levels, and hydrogen tank levels to calculate the range of the vehicle. Photo: Adam GlanzmanThe few prototypes developed previously by some companies were inefficient and expensive, he says. “So far as we know, we are the first fully open-source, rigorously documented, tested and released-as-a-platform, [fuel cell] motorcycle in the world. No one else has made a motorcycle and tested it to the level that we have, and documented to the point that someone might actually be able to take this and scale it in the future, or use it in research.”He adds that “at the moment, this vehicle is affordable for research, but it’s not affordable yet for commercial production because the fuel cell is a very big, expensive component.” Doosan Fuel Cell, which provided the fuel cell for the prototype bike, produces relatively small and lightweight fuel cells mostly for use in drones. The company also produces hydrogen storage and delivery systems.The project will continue to evolve, says team member Annika Marschner, a sophomore in mechanical engineering. “It’s sort of an ongoing thing, and as we develop it and make changes, make it a stronger, better bike, it will just continue to grow over the years, hopefully,” she says.While the Electric Vehicle Team has until now focused on battery-powered vehicles, Marschner says, “Right now we’re looking at hydrogen because it seems like something that’s been less explored than other technologies for making sustainable transportation. So, it seemed like an exciting thing for us to offer our time and effort to.”Making it all work has been a long process. The team is using a frame from a 1999 motorcycle, with many custom-made parts added to support the electric motor, the hydrogen tank, the fuel cell, and the drive train. “Making everything fit in the frame of the bike is definitely something we’ve had to think about a lot because there’s such limited space there. So, it required trying to figure out how to mount things in clever ways so that there are not conflicts,” she says.Marschner says, “A lot of people don’t really imagine hydrogen energy being something that’s out there being used on the roads, but the technology does exist.” She points out that Toyota and Hyundai have hydrogen-fueled vehicles on the market, and that some hydrogen fuel stations exist, mostly in California, Japan, and some European countries. But getting access to hydrogen, “for your average consumer on the East Coast, is a huge, huge challenge. Infrastructure is definitely the biggest challenge right now to hydrogen vehicles,” she says.She sees a bright future for hydrogen as a clean fuel to replace fossil fuels over time. “I think it has a huge amount of potential,” she says. “I think one of the biggest challenges with moving hydrogen energy forward is getting these demonstration projects actually developed and showing that these things can work and that they can work well. So, we’re really excited to bring it along further.”

Aditya Mehrotra performs a “shakedown” test — running the hydrogen-powered electric motorcycle at high speeds to ensure that the mechanical and electrical systems hold up. Photo: Adam Glanzman

MIT Electric Vehicle Team builds a unique hydrogen fuel cell–powered electric motorcycle.

The future of motorcycles could be hydrogen

In this episode, we dive into how MIT researchers have found a new way of efficiently leveraging the abundant carbon dioxide in the atmosphere to create clean, stable fuel capable of addressing Hydrogen’s shortcomings while still offering its core benefits!

Podcast: Converting CO2 To Clean Fuel

Ammonia, a main component of many fertilizers, could play a key role in a carbon-free fuel system as a convenient way to transport and store clean hydrogen. The chemical, made of hydrogen and nitrogen (NH3), can also itself be burned as a zero-carbon fuel. However, new research led by Princeton University illustrates that even though it may not be a source of carbon pollution, ammonia’s widespread use in the energy sector could pose a grave risk to the nitrogen cycle and climate without proper engineering precautions.Publishing&nbsp;<a href="https://www.pnas.org/doi/10.1073/pnas.2311728120" target="_blank">their findings</a> November 6 in&nbsp;PNAS, the interdisciplinary team of 12 researchers found that a well-engineered ammonia economy could help the world achieve its decarbonization goals and secure a sustainable energy future. A mismanaged ammonia economy, on the other hand, could ramp up emissions of nitrous oxide (N2O), a long-lived greenhouse gas around 300 times more potent than CO2&nbsp;and a major contributor to the thinning of the stratospheric ozone layer. It could lead to substantial emissions of nitrogen oxides (NOx), a class of pollutants that contribute to the formation of smog and acid rain. And it could directly leak fugitive ammonia emissions into the environment, also forming air pollutants, impacting water quality, and stressing ecosystems by disturbing the global nitrogen cycle.Fortunately, the researchers found that the potential negative impacts of an ammonia economy can be minimized with proactive engineering practices. They argued that now is the time to start seriously preparing for an ammonia economy, tackling the potential sticking points of ammonia fuel before its widespread deployment.“We know an ammonia economy of some scale is likely coming,” said research leader&nbsp;<a href="https://engineering.princeton.edu/faculty/amilcare-porporato" target="_blank">Amilcare Porporato</a>, the Thomas J. Wu ’94 Professor of Civil and Environmental Engineering and the&nbsp;<a href="https://environment.princeton.edu/" target="_blank">High Meadows Environmental Institute</a>. “And if we are proactive and future-facing in our approach, an ammonia economy could be a great thing. But we cannot afford to take the risks of ammonia lightly. We cannot afford to be sloppy.”<h2>Translating ammonia from agriculture to energy</h2>As interest in hydrogen as a zero-carbon fuel has grown, so too has an inconvenient reality: it is notoriously difficult to store and transport over long distances. The tiny molecule must be stored at either temperatures below -253 degrees Celsius or at pressures as high as 700 times atmospheric pressure, conditions that are infeasible for widespread transport and prone to leakage.Ammonia, on the other hand, is much easier to liquify, transport, and store, capable of being moved around similarly to tanks of propane.Moreover, an established process for converting hydrogen into ammonia has existed since the early 20th century. Known as the Haber-Bosch process, the reaction combines atmospheric nitrogen with hydrogen to form ammonia. While the process was originally developed as a cost-effective way to turn atmospheric nitrogen into ammonia for use in fertilizers, cleaning products, and even explosives, the energy sector has looked to the Haber-Bosch process as a way to store and transport hydrogen fuel in the form of ammonia.Ammonia synthesis is inherently energy-intensive, and fossil fuels without CO2 capture are currently used to meet almost all of its feedstock and energy demands. But as the researchers pointed out in their article, if new, electricity-driven processes that are currently under development can replace conventional fossil-fuel-derived ammonia synthesis, then the Haber-Bosch process — or a different process altogether — could be widely used to convert clean hydrogen into ammonia, which can itself be burned as a zero-carbon fuel.“Ammonia is an easy way to transport hydrogen over long distances, and its widespread use in agriculture means there is already an established infrastructure for producing and moving ammonia,” said&nbsp;<a href="https://environment.princeton.edu/people/matteo-bertagni/" target="_blank">Matteo Bertagni</a>, postdoctoral researcher at the High Meadows Environmental Institute working on the&nbsp;<a href="https://cmi.princeton.edu/" target="_blank">Carbon Mitigation Initiative</a>. “You could therefore create hydrogen in a resource-rich area, transform it into ammonia, and then transport it anywhere it’s needed around the globe.”Ammonia’s transportability is especially attractive to industries reliant on long-distance transportation, such as maritime shipping, and countries with limited available space for renewable resources. Japan, for example, already has a national energy strategy in place that incorporates the use of ammonia as a clean fuel. Straightforward storage requirements mean that ammonia might also find use as a vessel for long-term energy storage, complementary to or even replacing batteries.“At first glance, ammonia seems like an ideal cure for the problem of decarbonization,” Porporato said. “But almost every medicine comes with a set of potential side effects.”<h2>‘Look before we leap’</h2>In theory, burning ammonia should yield only harmless nitrogen gas (N2) and water as products. But in practice,&nbsp;<a href="https://engineering.princeton.edu/faculty/michael-mueller" target="_blank">Michael E. Mueller</a>, associate chair and professor of mechanical and aerospace engineering, stated that ammonia combustion can release harmful NOx­&nbsp;and N2O pollutants.Most N2O emissions from ammonia combustion are the result of disruptions to the combustion process. “N2O is essentially an intermediate species in the combustion process,” Mueller said. “If the combustion process is allowed to finish, then there will be essentially no N2O emissions.”Yet Mueller said that under certain conditions, such as when a turbine is ramping up or down or if the hot combustion gases impinge upon cold walls, the ammonia combustion process can become disrupted and N2O emissions can quickly accumulate.For instance, the researchers found that if ammonia fuel achieves a market penetration equal to around 5% of the current global primary energy demand (which would require 1.6 billion metric tons of ammonia production, or ten times current production levels), and if 1% of the nitrogen in that ammonia is lost as N2O, then ammonia combustion could produce greenhouse gas emissions equivalent to 15% of today’s emissions from fossil fuels. The greenhouse gas intensity of such a loss rate would mean that burning ammonia fuel would be more polluting than coal.Like ammonia’s N2O emissions,&nbsp;<a href="https://mae.princeton.edu/people/faculty/socolow" target="_blank">Robert Socolow</a>, a professor of mechanical and aerospace engineering, emeritus, and senior scholar at Princeton, said that widespread usage of ammonia in the energy sector will add to all the other impacts that fertilizer has already had on the global nitrogen cycle.In a&nbsp;<a href="https://www.pnas.org/doi/abs/10.1073/pnas.96.11.6001" target="_blank">seminal paper</a> published in 1999, Socolow discussed the environmental impacts of the food system’s widespread use of nitrogen-enriched fertilizers to promote crop growth, writing that, “Excess fixed nitrogen, in various guises, augments the greenhouse effect…contaminates drinking water, acidifies rain…and stresses ecosystems.”As the energy sector looks toward ammonia as a fuel, Socolow said that it can learn from agriculture’s use of ammonia as a fertilizer. He urged those in the energy sector to consult the decades of work from ecologists and agricultural scientists to understand the role of excess nitrogen in disturbing natural systems.“Ammonia fuel can be done, but it cannot be done in any way we wish,” said Socolow, whose 2004 paper with&nbsp;<a href="https://eeb.princeton.edu/people/stephen-pacala" target="_blank">Stephen Pacala</a>, the Frederick D. Petrie Professor in Ecology and Evolutionary Biology, emeritus, on&nbsp;<a href="https://www.science.org/doi/abs/10.1126/science.1100103" target="_blank">stabilization wedges</a> has become a foundation of modern climate policy. “It’s important that we look before we leap.”<h2>A roadmap for a sustainable ammonia economy</h2>While the environmental consequences of an ammonia economy gone wrong are serious, the researchers emphasized that the potential stumbling blocks they identified are solvable through proactive engineering.“I interpret this paper as a handbook for engineers,” Mueller said. “By identifying the worst-case scenario for an ammonia economy, we’re really identifying what we need to be aware of as we develop, design, and optimize new ammonia-based energy systems.”For instance, Mueller said there are alternative combustion strategies that could help to minimize unwanted NOx and N2O emissions. While each strategy has its own set of pros and cons, he said that taking the time now to evaluate candidate systems with an eye toward mitigating emissions will ensure that combustion systems are poised to operate optimally for ammonia fuel.Another option for accessing the energy in ammonia involves partially or fully splitting ammonia back into hydrogen and atmospheric nitrogen through a process known as cracking. Ammonia cracking, a line of research being actively pursued by&nbsp;<a href="https://engineering.princeton.edu/faculty/emily-carter" target="_blank">Emily A. Carter</a>, could help to make the fuel composition more favorable for combustion or even bypass the environmental concerns of ammonia burning by regenerating hydrogen fuel at the point of use. Carter is the Gerhard R. Andlinger Professor of Energy and the Environment and senior strategic advisor and associate laboratory director for applied materials and sustainability sciences at the&nbsp;<a href="https://www.pppl.gov/" target="_blank">Princeton Plasma Physics Laboratory</a> (PPPL).Furthermore, several technologies already exist at the industrial scale to convert unwanted NOx emissions from combustion back into N2 through a process known as selective catalytic reduction. These technologies could be straightforward to transfer to ammonia-based fuel applications. And as a convenient bonus, many of them rely on ammonia as a feedstock to remove NOx — something that there would already be plenty of in an ammonia-based system.Beyond the engineering practices that could be developed to minimize the environmental impacts of an ammonia economy, Porporato said future work will also look beyond engineering approaches to identify policies and regulatory strategies that would ensure the best-case scenario for ammonia fuel.“Imagine the problems we could have avoided if we knew the risks and environmental impacts of burning fossil fuels before the Industrial Revolution began,” Porporato said. “With the ammonia economy, we have the chance to learn from our carbon-emitting past. We have the opportunity to solve the challenges we’ve identified before they become an issue in the real world.”<hr>The paper, “<a href="https://www.pnas.org/doi/10.1073/pnas.2311728120" target="_blank">Minimizing the Impacts of the Ammonia Economy on the Nitrogen Cycle and Climate</a>,” was published November 6 in PNAS. In addition to Porporato, Bertagni, Mueller, Socolow, and Carter, coauthors include J. Mark P. Martirez of the Princeton Plasma Physics Laboratory (PPPL); Chris Greig, Yiguang Ju, Sankaran Sundaresan, Mark Zondlo, and Rui Wang of Princeton University; and Tim Lieuwen of the Georgia Institute of Technology. The research was supported by the U.S. Department of Energy, the National Science Foundation, the BP-funded Carbon Mitigation Initiative at Princeton University, and the Moore Foundation.

While interest in the use of ammonia as a hydrogen carrier and zero-carbon fuel grows, a Princeton-led team of researchers found that a mismanaged ammonia economy could have unwanted environmental consequences. (adobe.stock.com)

Ammonia, a main component of many fertilizers, could play a key role in a carbon-free fuel system as a convenient way to transport and store clean hydrogen. The chemical, made of hydrogen and nitrogen (NH3), can also itself be burned as a zero-carbon fuel.

Ammonia fuel offers great benefits but demands careful action

This article originally appeared in&nbsp;<a href="https://ethz.ch/en/news-and-events/eth-news/news/2023/10/heavy-trucks-likely-not-zero-emission-in-the-near-future.html" target="_blank" id="isPasted" rel="noopener noreferrer">ETH Zurich</a> and has been republished with permission.<hr>What will power lorries in the future? Climate-damaging diesel, or emission-free technologies such as batteries or hydrogen? Whether the international community achieves the Paris climate target of net zero greenhouse gas emissions by 2050 also depends on whether it succeeds in decarbonising heavy goods traffic. This is because these account for almost one-third of annual global emissions in the transport sector, which is responsible for around one-fifth of CO2 emissions worldwide.Researchers at ETH Zurich have now developed a model to investigate which technologies will prevail in truck traffic by 2035. The results are sobering: a large proportion of heavy lorries will continue to be powered by diesel or liquefied natural gas (LNG). “Without political measures to decarbonise heavy goods traffic, green technologies have no chance,” explains Tobias Schmidt, Professor of Energy and Technology Policy at ETH Zurich and coauthor of the study, which has just been published in the journal Proceedings of the National Academy of Sciences (PNAS).<h2>Focus on overall costs</h2>In their model, the researchers consider three weight classes with different driving profiles: on average, vans weighing roughly 3.5 tonnes and covering 75 kilometres a day without loading or refuelling; medium goods vehicles weighing roughly 7.5 tonnes and covering 200 kilometres a day; and heavy goods vehicles weighing roughly 32 tonnes and covering 600 kilometres a day.The adoption of zero-emission trucks powered by batteries or green hydrogen hinges on their cost relative to traditional internal combustion engine vehicles. The researchers assume that investors focus on total costs incurred over the lifetime of a truck.These costs consist of procurement and operating costs such as the cost of fuel, wages, maintenance, insurance and tolls. The researchers further assume that companies will partly invest in the recharging and refuelling infrastructure of battery and hydrogen trucks themselves. These costs are charged to an electric truck for the use of the infrastructure over its lifetime.<h2>Operating costs are decisive</h2>“When all lifetime costs are taken into account, battery-powered vans and medium goods vehicles are already cheaper than diesel lorries in many European countries,” says Bessie Noll, a postdoctoral researcher in Schmidt’s research group and the study’s lead author. This is due to their lower operating costs over the entire service life. Hydrogen lorries are by far the most expensive in these two weight classes, the reason being high prices for fuel cells and green hydrogen.It’s a different story for heavy lorries: diesel and LNG remain the cheapest fuels, with green hydrogen the most expensive option. Only in Switzerland are heavy goods vehicles powered by batteries or green hydrogen already cheaper today. The reason for this is the high toll costs that diesel lorries incur due to the country’s distance-related heavy vehicle fee (HVF). Emission-free vehicles over 3.5 tonnes are exempt from this toll.“Whether CO2-free lorries are competitive currently depends on whether their higher purchase price is offset by lower operating costs over their entire service lifetime,” Noll says. The researchers show that fuel prices and toll expenses play a significant role in this regard.<h2>No progress on heavy goods traffic</h2>Moreover, the model calculations show that the electrification of goods traffic by 2035 is progressing only for light and medium goods vehicles. New battery-powered vehicles will achieve a global market share of over 50 percent in these two vehicle classes by 2035. In Europe and China, they will even account for 70 percent of the total. “We estimate that by 2035, around one-third of new lorries purchased worldwide in the small and medium weight segments will be diesel vehicles,” Noll says.Things look worse for heavy trucks over 32 tonnes, where the global market share of new lorries that are CO2-free will remain below 10 percent in 2035. For the researchers, one thing is clear: without effective policies that support green powertrain technologies, the majority of heavy lorries will continue to be powered by diesel engines in 2035.A comparison of different measures also shows that lower toll costs for zero-emission lorries, as practiced in Switzerland, would be the most effective policy instrument to help green technologies achieve a breakthrough in heavy goods traffic.<h2>Hydrogen is not competitive</h2>According to the ETH Zurich study, small vans and medium-sized lorries are being electrified almost exclusively with batteries. Hydrogen-powered lorries are simply too expensive in most countries or regions. But there is one exception: in the EU, hydrogen lorries over 32 tonnes could gain some degree of market share. This is mainly related to the assumption that the EU will subsidise green hydrogen in the future, making it cheaper than in other parts of the world.One reason that batteries are more competitive than green hydrogen for lorries is that a hydrogen-powered truck requires about three times as much renewable electricity as a battery-powered one. “The operating costs are significantly higher with green hydrogen because a lot of energy is lost in the production, distribution and conversion of green hydrogen into electricity,” Schmidt says.What’s more, it can be assumed that the costs for battery-powered lorries will fall faster than those for hydrogen ones. The reason for this is that the global market share of battery-powered vehicles (cars and lorries) is already significantly higher, leading to greater economies of scale. Added to this is the fact that fuel cells that run on hydrogen are a more complex technology: they require extensive heating, ventilation and air conditioning systems and are generally higher maintenance. “Batteries already have a head start over hydrogen,” Professor Schmidt adds, “and they’re constantly extending their lead thanks to a steeper learning curve.”<hr><h2 id="isPasted">How to estimate future costs</h2>To find out which technology will prevail by 2035, the researchers simulated the potential purchasing decisions of heavy goods transport investors worldwide. The challenge is to predict how the total costs of different technologies will change over time. Based on historical data, the study authors make use of the correlation that the more widely a technology is deployed, the faster its costs decline. For example, based on a technology’s increased market share this year, they can estimate its cost next year and its market share the following year.However, the speed at which economies of scale materialize also depends on the complexity of the technology. “The more complex a technology is, the slower its costs fall,” Schmidt explains. The researchers also assume that switching from an established technology to a new technology results in conversion costs that make the new technology less attractive. They model these conversion costs with a calibrated markup on the purchase price.<hr><h2 id="isPasted">Reference</h2>Noll B, Steffen B, Schmidt T, The effects of local interventions on global technological change through spillovers: a modeling framework and application to the roadfreight sector, The Proceedings of the National Academy of Sciences (PNAS), doi: <a href="https://doi.org/10.1073/pnas.2215684120" target="_blank">external page10.1073/pnas.2215684120</a>Noll B, del Val S, Steffen B, Schmidt T, Analyzing the competitiveness of low-carbon drive-technologies in road-freight: A total cost of ownership analysis in Europe, Applied Energy, Volume 306, Part B, 15 January 2022, doi: <a href="https://doi.org/10.1016/j.apenergy.2021.118079" target="_blank">external page10.1016/j.apenergy.2021.118079</a>

Without political measures for zero-​emission technologies, a significant proportion of heavy goods vehicles will still run on diesel in 2035. This result is shown in a new ETH Zurich study on the decarbonisation of truck traffic.

Heavy trucks likely not zero-emission in the near future

This article is a part of our <a href="http://www.wevolver.com/student-program" target="_blank">University Technology Exposure Program</a>. The program aims to recognize and reward innovation from engineering students and researchers across the globe.Community voting is now live. Vote for your favorite submission by visiting:&nbsp;<a href="https://www.wevolver.com/utep-community-vote/" rel="noopener noreferrer" target="_blank">University Technology Exposure Program Community Vote</a>.&nbsp;That hydrogen has a lot of potential as a fuel has been known for years, the first mention of a hydrogen economy happened in the year 1970. Still, there is a long way to go to make hydrogen fit in our future energy mix. Hydrogen, when produced with renewable energy, is a sustainable energy carrier. However, hydrogen has some problems. It is a flammable and light gas and must be stored under high pressure. This makes transport and seasonal storage of hydrogen difficult and therefore expensive. &nbsp;Iron-based Hydrogen Storage (IRHYS) offers an alternative to existing hydrogen storage options. Instead of storing hydrogen under high pressure, iron is used as a storage technique. We as SOLID are planning to have a proof of concept for generating hydrogen from iron at the beginning of this summer.&nbsp;<h2 dir="ltr">The Process</h2>Oxidizing iron using steam (the steam-iron process) creates iron oxide (rust) and hydrogen. This hydrogen can be separated from the rust and can then be used for various applications. They produced iron oxide that can be regenerated by adding green hydrogen to the iron oxide. This creates a sustainable cycle where hydrogen can be stored and released when you need it. The cycle is shown in Figure 1.&nbsp;<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjQ3NDUzNDU0ODk3LTE2NDc0NTM0NTQ4OTcucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" class="fr-fic fr-dii" alt="IRHYS-system">Figure 1 IRHYS cycleIRHYS systems provide an efficient, safe, and possibly cheaper alternative to current hydrogen storage techniques. Iron is easier to store and transport than hydrogen because it only ignites at higher temperatures. Besides, it does not need to be stored under any pressure. Iron is a versatile substance. Not only is iron suitable for hydrogen storage, but the iron powder is fuel on its own.&nbsp;In this project, SOLID is going to make a proof of concept of the steam-iron oxidation reaction (the right part of the total cycle in an IRHYS system). The main focus of the project is the realization of a steam-iron oxidation reactor. This reactor must be suitable for converting iron pellets into rust and hydrogen by letting it react with steam. The technology is expected to be highly scalable and can be used to replace current hydrogen storage&nbsp;methods in various sectors. A simplified scheme of the oxidation process, which is taking place in the reactor, is shown in figure 2. &nbsp;The process starts with placing the iron pellets in the steam-iron oxidation reactor. With the help of an evaporator, steam is added to the reactor. This causes the oxidation reaction to take place. This reaction is an exothermic reaction that releases heat that can be used in the evaporator to generate more steam. The reaction that takes place in the reactor is:<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjQ3NDU0MjU3MTM4LTE2NDc0NTQyNTcxMzgucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 300px;" class="fr-fic fr-dib">After this reaction has taken place there is still a mix of hydrogen and water (steam) left, the water is filtered out in the condenser so that pure hydrogen is left and can be extracted from the reactor.&nbsp;An obstacle to our innovation is the lack of information about the reactor. As there is no physical reactor yet, it is not known what the exact purity of the created hydrogen, the total amount of hydrogen produced, or the reaction kinetics will be. These information gaps will be found during the testing phase of the proof of concept. This will take place in May 2022.&nbsp; <img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjQ3NDUzNDU0NTc5LTE2NDc0NTM0NTQ1NzkucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" class="fr-fic fr-dii" alt="oxidation-process">Figure 2 Scheme of the oxidation process [1]<h2>Application&nbsp;</h2>Currently, a lot of countries are building wind turbines and placing solar panels to achieve the goals described in the climate agreement and gain more green energy. However, the sun does not always shine and the wind does not always blow. While on the other hand there are moments that the energy supply is higher than the energy demand. The latter is the moment when the rust has to be regenerated to iron pellets. Whereafter these can be transported to anywhere in the world. Where the hydrogen can be extracted by oxidizing the pellets.&nbsp;Industries that use hydrogen as a fuel can use iron to store this hydrogen without having to keep it under strict storage regulations. Furthermore, transportation of hydrogen in iron can be done through the current infrastructure, so there are no changes required there.<h2 dir="ltr">Iron Fuel</h2>Iron has an additional function, it can also be used as fuel to generate heat. The process has a similar cycle as the IRHYS technology, shown in figure 3.&nbsp;<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjQ3NDUzNDU1MTM2LTE2NDc0NTM0NTUxMzYucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" class="fr-fic fr-dii">Figure 3 Generation of heat using IRHYSIn this technology, iron can be used as a method of storing energy in general, instead of merely hydrogen. The iron will be combusted instead of oxidized with steam, generating much heat. Iron Fuel has already been demonstrated at potential end-use, Swinkels Brewery, and is being scaled up as we speak.&nbsp;In this video, the process of Iron Fuel is explained further:&nbsp;<iframe width="640" height="360" src="https://www.youtube.com/embed/8rm6kc202PE?&wmode=opaque&rel=0&enablejsapi=1&origin=https://www.wevolver.com" frameborder="0" allowfullscreen="" class="fr-draggable" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-gtm-yt-inspected-1_19="true" id="564343540"></iframe> SOLID has not been working on this technology alone but worked in a consortium with many partners. These are: the TU/e, Metalot, EMGroup, HeatPower, Pometon, RIFT, RI.SE, Shell, and Romico. And the projects of this technology are supported by: Uniper, Enpuls, Nyrstar, Veolia, Swinkels, RWE, and Energy Storage NL.<h2 dir="ltr">Our Team</h2>SOLID is a student team of approximately 20 students every academic year. The team consists of full-time members and part-time members. We have several sub-teams in our team. Starting with the management team, making sure all subteams know what they have to do. The business team is working on the economic feasibility of IRHYS technology. The marketing team is promoting IRHYS but also Iron Fuel, making sure everybody knows the technology exists.&nbsp;<img alt="Afbeelding met persoon, groep, poseren Automatisch gegenereerde beschrijving" src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjQ3NDUzNDU2MTU1LTE2NDc0NTM0NTYxNTUucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" id="isPasted" class="fr-fic fr-dii"> The technical team is designing and building the reactor. And we also have our finance team, checking all the expenses and making sure we have enough money. At last, we have our HR team, keeping everybody in the team happy! The members of our team all have different educational backgrounds. Some are still in their bachelor&rsquo;s or are just finished with their bachelor&rsquo;s, while others are already in their masters. We as SOLID think it is important to help with the energy transition and contribute to a greener tomorrow. We strive to enable access to clean and renewable energy for anyone at any time!<h2>References</h2>[1] Brinkman, L., Bulfin, B., &amp; Steinfeld, A. (2021). Thermochemical Hydrogen Storage via the Reversible Reduction and Oxidation of Metal Oxides. Energy &amp; Fuels, 35(22), 18756&ndash;18767. <a data-reactroot="" data-token-index="1" href="https://doi.org/10.1021/acs.energyfuels.1c02615" id="isPasted" rel="noopener noreferrer" target="_blank">https://doi.org/10.1021/acs.energyfuels.1c02615</a><h2 dir="ltr" id="isPasted">About the University Technology Exposure Program 2022</h2>Wevolver, in partnership with <a href="https://mouser.com/" target="_blank">Mouser Electronics</a> and <a href="https://www.ansys.com/" target="_blank">Ansys</a>, is excited to announce the launch of the University Technology Exposure Program 2022. The program aims to recognize and reward innovation from engineering students and researchers across the globe. Learn more about the program <a href="http://www.wevolver.com/student-program" target="_blank">here</a>.<img alt="university-technology-exposure-program-mouser-ansys" src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjQ3NDU0NTkwMTY2LTE2NDc0NTQ1OTAxNjYucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" class="fr-fic fr-dii">

By making use of steam and iron pellets, hydrogen can be created with the only byproduct being rust and heat. By regenerating the rust with hydrogen, a completely circular, compact, safe and energy efficient hydrogen storage method is created.

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