New ammonia propulsion system enables carbon-free aviation to serve short-haul routes by 2050

Reporter : Huang Junzhi / Publisher : Financial Association Press 

Ref : http://www.minhangshi.com/m/h5/detail/8642257 / Direct translation

Image : Short-haul routes in the future will benefit from new ammonia propulsion system. Malindo Air operates short-haul flight to Singapore from KLIA.

According to reports, British aviation manufacturer Reaction Engines and the Science and Technology Facilities Committee (STFC) have completed a conceptual study on the practicality of using ammonia as jet aviation fuel. By combining the heat exchange technology of Reaction Engines with the advanced catalysts of STFC, they hope to create a sustainable, low-emission propulsion system for future aircraft.

Modern jet engines use a variety of fuels based on kerosene. This fuel has a very high energy density and can propel aircraft to fly long distances and transport passengers and cargo to all parts of the world. Unfortunately, this fuel also comes from fossil fuels, which will generate a lot of carbon dioxide emissions, and the aviation industry and many governments have pledged to completely reduce carbon dioxide emissions by 2050.

One way to achieve these reductions is to find alternatives to traditional jet fuel to drive aircraft. The problem is that most of the current alternative fuels have a much lower energy density than standard aviation fuels, and there are many other disadvantages. For example, current battery technology will require future aircraft to be very small, short range, and small in payload capacity. Liquid hydrogen may be a viable alternative fuel, but because of the need to carry large amounts of liquid hydrogen, aircraft must be redesigned and new infrastructure built.

The idea of ​​using ammonia as aviation fuel is not new. Although its energy density is only one-third of that of diesel, it is relatively easy to liquefy and store, and has been used by the famous X-15 rocket aircraft to promote it in a series of suborbital missions in the 1950s and 1960s Into space. In addition, it contains no carbon.

However, the tricky part is to find an economically feasible way to apply it to aviation. To solve this problem, Reaction Engines produced a new propulsion system based on the heat exchanger technology it developed for the SABRE supersonic engine, which was then submitted to STFC Rutherford Appleton Laboratory (Rutherford Appleton Laboratory). Laboratory) for evaluation.

In this new system, ammonia is stored in the aircraft wings in the form of a frozen, pressurized liquid, just like today’s kerosene fuel. The ammonia is heated by the heat collected from the engine by the heat exchanger. The ammonia is extracted and sent to the chemical reactor. The catalyst decomposes part of the ammonia into hydrogen. Then, the ammonia/hydrogen mixture is fed into jet engines, where they can be burned like conventional fuels, but the emissions are mainly nitrogen and water vapor.

According to ReactionEngines, the energy density of ammonia is high enough so that the aircraft does not require major modifications and the engine can be modified in a relatively short period of time. Ground testing is underway, and the first flight may take place in a few years.

Dr. James Barth, Engineering Lead of Reaction Engines, said, "The combination of our transformative heat exchange technology and STFC's innovative catalyst will make it possible to develop an epoch-making green amino aviation propulsion system."

"Ammonia-fueled jet engines can be retrofitted on existing engines without overturning and rethinking the design of existing civil aircraft. This means that it is possible to quickly transition to a sustainable aviation future at low cost. Before 2050, ammonia-powered aircraft can serve the world's short-haul routes." He added.