NH3 cracker produces fuel blend suitable for shipping

Sunborne’s ammonia reactor technology targets the retrofitting of existing fossil fuel-powered propulsion systems and energy generators. The core of the technology is a reactor which transforms stored liquid NH3 into an optimised blend of H2, N2 and uncracked NH3. The resulting cracked blend is easier to ignite and burn than pure NH3, and no GHG emissions released.

Cooled liquid NH3 is pressurised to maximise fuel storage density and provide the greatest possible heat sink for the system cooling (the liquid is -70°C). This NH3 is warmed and pumped into the reactor where some is converted to H2 and N2, while the rest of the fuel maintains the reactor temperature. Close thermal integration of the heating and cooling processes ensures overall high system efficiency, as does the relatively low temperature operation of the catalyst.

The company’s test programme has demonstrated the ability to produce a fuel blend sufficient to power a 56kW (75bhp) engine, equivalent to a small vehicle or mobile generator. The test results demonstrated a high degree of thermal efficiency and showed the potential for the architecture to be scaled into higher energy output internal combustion engine systems and other industrial power applications.

Sunborne is therefore aiming to secure funding for a 1MW engine demonstration in the next two years.

Dr James Barth, co-founder and CEO, said: “The potential impact of our technology is unprecedented, with significant potential to partner with major engine OEMs and bring a fuel revolution to drive the transition to net zero. Ammonia is already a widely traded commodity and will be traded even more in the future as hydrogen production facilities come online around the world. While our initial focus is on the maritime industry, which is leading decarbonisation of internal combustion engines, our technology could easily be applied to adjacent industries such as power generation and large heavy equipment, with significant potential for use with gas turbine technology in the future.”

Professor Bill David, co-founder and CSO, adds: “With around forty million tons of existing global ammonia excess capacity, our technology can immediately help make worldwide inroads into the transition to zero-carbon emissions in the transport and power sectors.”

Sunborne is a UK company founded in 2021 by Reaction Engines, the UK Science and Technology Facilities Council (STFC) and the cleantech venture investor Kiko Ventures. The ammonia reactor technology combines Reaction Engines’ thermal management and heat exchanger technology with the UK Technology & Science Facility Council’s expertise in catalyst chemistry, as well as drawing on the expertise in both organisations in system design and optimisation for a range of applications.