TOE

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ZEHST stands for Zero Emission High Speed ​​Transport (German: emission-free high-speed aircraft ). It describes a study presented by EADS at the Paris Air Show on June 18, 2011 for a quadruple supersonic passenger aircraft that is to operate without a negative greenhouse gas balance from the 2050s . The transport capacity is specified with 50 to 100 passengers, the range should be at least 9600 km ( London - Tokyo ).

Propulsion system and flight profile

A special feature of the design is the design of the aircraft with three different propulsion systems: two jet engines are to be used for take-off and climb to an altitude of approx. 5 km ; then two rocket engines powered by hydrogen and carried liquid oxygen would be ignited, which  would bring the aircraft to an altitude of 23 km and an airspeed of Mach 2.5, so that the two ramjet engines can be ignited as the main drive, which in principle require a very high inflow velocity.

The rocket engines thus close the gap between the optimal operating range of the jet engines and the minimum speed of the main drive. This should enable the use of space-saving and efficient jet engines for take-off and landing, while the ramjet engines can nevertheless be designed for efficient operation at high speeds.

The ramjet engines also use hydrogen as fuel, but burn it (in contrast to the rocket engines) with the atmospheric oxygen. The main engines should then bring ZEHST to its final cruising speed of Mach 4.0 (about 4100 km / h at the corresponding altitude) and cruising altitude of 32 km.

To end the cruise, the ramjet engines should be switched off and ZEHST should glide without propulsion to an altitude of 10 km, so that its speed decreased again into the subsonic range. To ensure a safe landing, the jet engines would then be restarted.

No emissions claim

Zero Emission Hyper Sonic Transport to three different fuels use: biofuel for the operation of jet engines, liquid hydrogen for the operation of the rocket engines and ramjet engines, and to a lesser extent liquid oxygen for rocket engines. Hydrogen and oxygen burn to pure water and can be obtained electrolytically from water, which requires electrical energy . The study aims to ensure that the drive would be CO 2 -neutral if the energy were generated from renewable sources. The bio-kerosene is to be obtained from renewable raw materials and only release as much carbon dioxide (CO 2 ) as it was previously bound when it was created. The balance is also CO 2 -neutral, provided that the energy used for production was also obtained from renewable sources.

What is not taken into account is that emissions do not only affect CO 2 , but any type of emission of disruptive factors into the environment . B. also be noise or the water released during combustion at great heights. Traces of water vapor brought into the stratosphere (15–50 km altitude) are particularly harmful to the climate.

Studies are also ongoing to operate conventional jet aircraft with biokerosene, which further calls into question the unique selling point “zero emissions”.

Web links

Individual evidence

  1. ↑ MailOnline: London to Tokyo in two hours: Blueprints for 3,000mph hypersonic plane are unveiled ... but it will take 40 years to build. Retrieved June 20, 2011 .
  2. ↑ Spiegel: Airbus is planning eco-Concorde. Retrieved June 20, 2011 .
  3. ↑ Handelsblatt: EADS dreams of a new Concorde. Retrieved June 20, 2011 .
  4. ↑ WeltOnline: From Paris to Tokyo in two and a half hours. Retrieved June 20, 2011 .
  5. ↑ FlugRevue: Lufthansa and Airbus are testing biofuel with the A321 between Hamburg and Frankfurt. Retrieved June 20, 2011 .