The concept of using ammonia as a fuel source isn’t a new one, it’s just making a comeback. During World War II, Europeans used liquid ammonia as a fuel substitute when diesel and gasoline were scarce. Now, with our improved understanding of ammonia’s potential as a clean energy source, it is emerging once again as a viable alternative.
And yet ammonia’s potential isn’t limited to powering trucks. There may be a future where ammonia fuel technology scales up to sectors like global shipping. Given that ammonia production, storage, and transportation infrastructures are already in place, the transition to using ammonia as a fuel source in these sectors seems feasible.
But ammonia’s value doesn’t stop at being a zero-carbon fuel source. Its ability to act as an energy storage medium is also significant. As the intermittency of renewable energy sources like solar and wind poses challenges, ammonia could step in as a crucial energy storage solution. It can store surplus energy efficiently, later releasing it when needed, thus mitigating the problem of intermittency.
Safety Concerns and Solutions Around Ammonia Use
Of course, ammonia use isn’t without its challenges. Its unpleasant odor and caustic nature pose safety concerns. Ammonia is a volatile compound, posing risks to the eyes, skin, and respiratory tract if leaked. However, these risks are not unique to ammonia — many traditional fuels pose similar hazards. Currently, researchers are diligently addressing these safety issues.
Additionally, scientists are working on improving the efficiency of green ammonia production and reducing the energy required for the “cracking” process. With continued technological advancements and safety measures, we could mitigate the potential hazards posed by ammonia, opening doors for wider adoption.
In the end, the path to a zero-emission future is still under construction, but ammonia’s potential as a fuel source is promising. With its high energy density, existing global infrastructure, and potential as an energy storage medium, ammonia could be a key player in decarbonizing heavy transportation and other sectors. As research and technology continue to progress, the day may come soon when our highways are buzzing with ammonia-powered trucks, driving us toward a sustainable future.
Exploring Dual-Use for Ammonia
Many companies around the globe are already working on dual-use solutions for ammonia fuel use. Hydrofuel Canada, as one example, is an Ontario-based company that offers an alternative way to leverage ammonia for powering trucks. Their approach involves injecting ammonia directly into the combustion engine along with a small amount of diesel or biodiesel to aid in combustion. A retrofit is required for this method, but the adjustments needed are reported to be straightforward and manageable.
The trials of this approach, like many projects worldwide, faced delays due to the challenges posed by the Covid-19 pandemic. However, Hydrofuel Canada remains hopeful about their method’s potential, especially in stationary engines and gensets. In fact, they plan to test a few such machines at a Toronto fleet soon.
The company asserts that ammonia is the most environmentally friendly fuel when compared with many other common options, including diesel, gasoline, and even electric where electricity is generated from fossil fuels. Given ammonia’s green potential, its role in heavy transportation may become increasingly relevant.
Ammonia as a Hydrogen Carrier
Zooming out to a broader view, ammonia’s key role might actually be as a hydrogen carrier, rather than as a direct zero-carbon fuel. Due to its chemical composition of three hydrogen atoms and one nitrogen atom, ammonia is an efficient medium to transport and store hydrogen for fuel cells, paving the way to a hydrogen economy.
While hydrogen’s energy density is nearly double that of ammonia, transporting and storing it presents significant challenges. For one, it needs to be supercooled to -253 degrees Celsius to maintain its liquid state, whereas ammonia only requires cooling to -33 degrees Celsius. Moreover, existing infrastructure can be used to ship, store, and distribute ammonia, providing a significant cost advantage over hydrogen.
Herein lies the circular nature of ammonia’s role. Ammonia is generated from hydrogen, stored and transported as required, and then ‘cracked’ back into hydrogen at the point of use. As Tim Hughes, an energy storage researcher at Siemens in the U.K., succinctly puts it, “You can store it, ship it, burn it, and convert it back into hydrogen and nitrogen. In many ways, it’s ideal.”
Where Does “Green Ammonia” Come Into Play?
However, for ammonia to truly be a part of a green energy solution, we need to produce “green” ammonia. The traditional method of ammonia production is known as the Haber-Bosch process. It involves stripping hydrogen from natural gas, and combining it with nitrogen under high pressure and extreme temperatures. While effective, this method has a significant environmental footprint, releasing two tons of CO2 for each ton of ammonia produced.
The challenge then is to remove natural gas from the process and produce hydrogen through electrolysis, utilizing electricity sourced from renewable sources. This is how green hydrogen generates ammonia. This is an area of active exploration, with projects underway across the globe, from Canada to Australia.
The largest project currently is based in Saudi Arabia, set to produce a million tons of ammonia per year from 2025 onwards. Comparatively smaller, but no less important, a plant in Louisiana aims to produce 20,000 tons of green ammonia annually starting this year.
A Promising Future for Ammonia
The possibility of a multi-fuel engine retrofit could be of interest. The real significance, though, is the implication that we may be closer to having commercially available hydrogen fuel cell-powered trucks. And this at a potentially lower cost. As the technology evolves and the range of battery-powered trucks increases, this could become a viable and attractive option for many.
As we move towards a more sustainable future, it’s becoming clear that ammonia could be a significant player. This is true both in the energy market and in the transportation sector. Given its global availability and the existing infrastructure for its storage and transportation, ammonia presents a feasible alternative fuel that aligns with global decarbonization goals. Furthermore, as our understanding of ammonia’s potential expands, so too do the possibilities for its application.
One such application is the use of ammonia in fuel cells. Fuel cells combine hydrogen and oxygen to produce electricity, heat, and water. Hydrogen fuel cells are a promising technology for clean power, especially for vehicles. However, the production, storage, and transportation of hydrogen pose significant challenges for end users. Why? Because it must be cooled to very low temperatures to remain in a liquid state, and its energy density is relatively low.
This is where ammonia comes in. The use of ammonia as an energy carrier for hydrogen could help to overcome some of the challenges associated with hydrogen fuel cells. Its energy density by volume is nearly double that of hydrogen. Even more, it requires fewer extreme conditions for storage. This makes it a more efficient and practical option for energy storage and transportation. This type of innovation could see hydrogen fuel cell vehicles gain on EVs in popularity.
The Work Ahead for Ammonia as Fuel
Despite the promise of ammonia as a green fuel, there is still a lot of work to do. The technology for “green” ammonia production is still under development. And while there are several promising projects underway, it’s going to take time to scale up.
While ammonia can be used as a fuel, the technology as a hydrogen carrier is still under development. This involves “cracking” the ammonia to extract the hydrogen, a process that requires catalysts and specific conditions.
Ammonia is caustic and can be dangerous if not handled properly. Any large-scale implementation of ammonia as a fuel would require stringent safety measures and protocols. This is why it’s important to consider safety when handling ammonia.
While there are many hurdles to overcome, the potential benefits of ammonia as a zero-carbon fuel are undeniable. Its global availability, existing transportation and storage infrastructure, and potential applications make it an attractive alternative to traditional fuels. As technology continues to evolve, we may see ammonia playing a central role in the global energy market. Many may find it useful in the fight against climate change.
But as with any disruptive technology, the journey from concept to implementation will be a challenging one. Industry will need to learn and adapt. For now, the focus must be on continuing to explore and develop the potential of ammonia as a green fuel. This involves not only technological innovation but also policy and regulatory changes, infrastructure development, and public and private investment. It’s a journey that we must undertake together, for the future of our planet.