The company is a collaboration between STFC and aerospace manufacturer Reaction Engines' heat exchanger technology with funding from intellectual property commercialisation investors, IP Group. The new venture will design and bring to market compact lightweight ammonia cracking reactors which will enable the provision of net-zero solutions for hard-to-decarbonise sectors.
Net Zero challenge in aviation
At present, aviation and shipping account for 5% of total global carbon emissions and both sectors are expected to see significant increases in carbon emissions over the coming years. But this new technology means aircraft and ships that leave nothing but water vapour and nitrogen in their wake could be a reality before the end of this decade.
Ammonia has a well-established global infrastructure of storage and transportation, but, on its own, it is challenging to combust. Hydrogen, on the other hand, combusts very readily but storage is a challenge. If the best fuel aspects of ammonia and hydrogen could be combined together then future air travel would be entirely carbon-free. The new ammonia cracking technology will produce an ammonia-hydrogen mixture that mimics jet-fuel performance, and importantly offers an affordable route to jet-zero through retrofitting existing aircraft.
What is ammonia cracking?
The technology under development uses a heat exchanger to warm in-wing stored liquid ammonia as it travels to the engine, through a cracking reactor that uses a novel catalyst to partially crack the ammonia (NH3) into its constituent elements, hydrogen (H2) and nitrogen (N2).
This real-time production of a blended ammonia-hydrogen mixture results in a fuel that closely resembles the jet-fuel propulsion properties and when completely combusted leaves behind only nitrogen, water vapour and no particulates.
There is, however, the potential of nitrogen oxides, NOx , as by-products. These greenhouse gases are a significant issue for all current and future jet fuels: kerosene, hydrogen and ammonia. Ammonia, however, has an important advantage as can scrub its own emissions as it readily reacts with NOx gases to produce nitrogen and water; ammonia is the active component of AdBlue which is used to mitigate NOx in heavy duty vehicles.
Bringing together research and industry
The breakthrough in ammonia cracking catalysts is the result of a series of important insights obtained over a decade of research at ISIS. Professor Bill David FRS, STFC Senior Fellow at ISIS and Professor of Energy Materials Chemistry at the University of Oxford, played a key role in the development of these materials. He says, “In 2011, an industrial collaborator challenged us to come up with a metal hydride material that could store hydrogen at moderate pressures. This is a difficult challenge for on-board storage that still remains today. Mulling over the challenge, I realised that if we looked at the reaction mechanism from another angle then a particular family of hydrogen storage materials would be able to crack ammonia effectively. This was accomplished through the iterative process of catalyst materials development and ammonia cracking experiments in the ISIS Hydrogen and Ammonia Laboratory, and in-situ neutron diffraction measurements at ISIS that provided unique insights the nature of the catalysts and the catalysis reactions."
This research underpinned the core technology that received funding as part of an internal STFC Proof of Concept Programme, which supports STFC scientists and engineers in collaboration with industry to deliver real-world impact from ground-breaking innovation.
Bill says, “I am excited about the impact that our technology can have in enabling low-impact transitions in hard-to-abate energy sectors. Playing to the complementary strengths of ammonia and hydrogen, our cracker technology can rely on the global ammonia infrastructure to provide, at scale, blended ammonia-hydrogen fuels that mimic fossil fuel performance and offer affordable retrofitted energy solutions."
Read the press release here.