High efficiency ammonia cracking—a carbon-free foundation for clean hydrogen fuel

As our heaviest industries work to reach Net Zero, the need for carbon-free energy has never been higher. The potential of hydrogen-derived fuel has attracted a lot of attention—there will be no climate solution without it—but the financial and logistical hurdles are a major barrier to global adoption and scalability. As a result, industry leaders, policymakers, non-governmental organizations, and investors are now turning to carriers like ammonia to deliver on the promise of hydrogen—and with good reason. 

Ammonia has 2.7x the energy density of hydrogen, making it perfect for applications in maritime (both on and offshore), power generation, and heavy-duty transportation. The global ammonia production and supply chain is also supported by over a hundred years’ worth of infrastructure, allowing it to bypass one very big—and expensive—hurdle standing in the way of developing the hydrogen economy.   

Crucially, ammonia is carbon-free by chemistry, so unlike other hydrogen carriers, it can be “cracked” without producing harmful emissions. Ammonia cracking is the process of splitting ammonia into its base elements—nitrogen and hydrogen. That hydrogen can then be used to power intensive workloads unsuitable for other clean energy solutions like lithium batteries.  

How does ammonia cracking work? 

Ammonia cracking takes place in an ammonia cracker. These devices or systems typically consist of a reactor vessel and other components like heating elements, catalyst beds, as well as controls for temperature and flow.

Cleaner than combustion 

Ammonia cracking shouldn’t be confused with ammonia combustion, which involves the reaction of ammonia with oxygen to produce nitrogen gas and water vapor. Ammonia combustion releases heat energy and is often used for generating heat or power in combustion engines or boilers. 

More efficient ammonia cracking 

Ammonia cracking is an endothermic process, which simply means breaking the chemical bonds of an ammonia molecule requires heat—a lot of heat. How much largely depends on what catalyst is being used. This is important, because the higher the temperature needed to crack ammonia, the less efficient (and more expensive) the process becomes.  

High conversion at low temperatures 

Catalysts play a crucial role in the economic viability, effectiveness, and efficiency of ammonia cracking. They accelerate the reaction rate and lower the activation energy required for ammonia molecules to break apart. They can also help to optimize the hydrogen yield while minimizing unwanted byproducts.

Traditional ammonia cracking takes place at temperatures ranging from 700-900ºC using non-platinum group metal (PGM) catalysts. Iron-based mix metal catalysts can crack ammonia at temperatures of around 600-750 ºC. However, today’s most effective catalysts use ruthenium metal. At Amogy, we use ruthenium in our own catalysts which can be 30% more efficient than alternative options thanks to a combination of high conversion rates and low operating temperatures.

Cracking the clean energy code 

Ammonia cracking will play a critical role in the journey to Net Zero, giving our heaviest industries access to clean hydrogen fuel at scale. This, combined with the growing production of green ammonia, leaves ammonia poised to accelerate progress towards an emission-free future. 

At Amogy, we’re building technologies and products capable of making ammonia cracking more cost-effective, efficient and scalable. Our technology makes it possible to integrate an ammonia cracker, in the form of a modular ammonia-to-electrical power system, into existing power generation systems, aboard retrofit or new build vessels, and more. This year, we will be launching the world’s first ammonia-powered vessel—the NH3 Kraken.

If you’re interested in learning about ammonia as an alternative fuel, check out our recent whitepaper: Ammonia as an Essential Energy Carrier for the Energy Transition.