British air-breathing rocket propulsion technology company Reaction Engines, UK state research and development organisation, the Science and Technology Facilities Council (STFC), and venture capital enterprise, the IP Group, have combined to create a joint venture (JV) to advance the decarbonisation of the aerospace, other transport, and power generation sectors. It will do so by making ammonia a viable zero-carbon fuel.
Reaction Engines will provide its revolutionary heat exchanger technology (developed as part of its SABRE air-breathing rocket engine project), while STFC will contribute its leading ammonia catalyst technology and the IP Group will supply the funding. Ammonia (chemical formula NH3) cannot be used as a fuel ‘as is’, because it is stable and quite inert. To turn it into a fuel requires that it be ‘cracked’, that is, broken down into its component elements, hydrogen and nitrogen. But not all the ammonia needs to be ‘cracked’ to provide a fuel: hydrogen produced by cracking some of the ammonia can be mixed with the remaining ammonia to produce a viable hydrogen/ammonia fuel blend.
Using ammonia instead of pure hydrogen as a fuel offers many advantages. Whereas liquid hydrogen has to be stored and transported at a temperature of –253 °C, ammonia can be stored and transported at the much higher temperature of –33 °C. Large scale and well understood supply chains and storage facilities for ammonia already exist, and ammonia has a higher volumetric energy density than hydrogen. However, the three partners in the new JV foresee ammonia as complementing and not eliminating hydrogen as an aviation fuel.
Reaction Engines’ heat exchanger will use waste heat from a jet engine to power a compact and lightweight ammonia catalyst reactor, or ‘cracker’, developed by STFC. Each cracker/heat exchanger unit would be installed next to each engine pod on an aircraft wing. Installation would require changes to (replacement of) the aircraft’s wings and fuel tanks, but not to its fuselage or empennage. The engines themselves would need only small adjustments. One drawback, identified in modelling by Reaction Engines (based on an Airbus A320), would be that an airliner subjected to these minimum modifications would suffer a reduction in range to 2 000 km, but that this would still cover 90% of the most popular routes. This lost range would be restored if greater changes were made to the aircraft’s design.
“After completing STFC funded proof-of-concept projects, I am excited about the impact that our technology can have in enabling low-impact transitions in hard-to-abate energy sectors,” said Oxford University energy materials chemistry professor and STFC senior fellow Professor Bill David. “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.”
“I am thrilled to see the hard work we’ve been undertaking with our partners at STFC culminate in the formation of a new joint venture to bring to market decarbonisation technology solutions,” enthused Reaction Engines Ammonia Programme lead Dr James Barth. “Having IP Group’s backing for Reaction Engines’ first commercial spin-out is a huge vote of confidence in the compact, lightweight ammonia reactor technology we are developing. We are excited to work together to help decarbonise power and propulsion systems in transport, power generation, and other hard to abate sectors.”
“As the leading cleantech venture investor in the UK, we are delighted to be partnering with two of the country’s most innovative organisations to pursue ammonia for energy,” affirmed IP Group Cleantech head Dr Robert Trezona. “The combination of technologies from Reaction Engines and STFC is a profound breakthrough and we are excited to be joining forces to build a technology champion in this space.”
Reaction Engines’ strategic partners include aerospace giants BAE Systems, Boeing and Rolls-Royce.