Ecojet signs purchase agreement for 22 ZeroAvia hydrogen-electric engines, with options for 40 more
29 July 2024
Ecojet, the world’s first electric, commercial airline, has signed an agreement to purchase 22 ZA2000 hydrogen-electric engines from ZeroAvia, with options for a further 40 engines.
The ZA2000 is a 2-5MW modular hydrogen-electric powertrain for up to 80 seat regional turboprops. Fueled by liquid hydrogen tanks, the powertrain is capable of carrying passengers up to 1000 NM. The ZA2000 engine can be retrofitted into 40-80 seat regional turboprops for zero-emission flight.
The agreement deepens the commitment announced last November 2023, with a deposit schedule that will ensure Ecojet secures some of the first production slots of ZeroAvia ZA2000 powertrains post certification.
Ecojet is aiming to launch services in late 2024 with conventionally-powered aircraft, operating routes to and from Edinburgh and retrofitting them once the technology is certified.
The airline will begin this journey by operating its first zero-emission aircraft with ZeroAvia’s ZA600 engines for up to 20 seat planes. Ecojet’s aim is to build a fleet of larger regional aircraft to serve passengers on key domestic and shorter international routes.
ZeroAvia has already extensively tested a prototype of its first ZA600-engine aboard a Dornier 228 aircraft at its UK base. The company has also performed advanced ground tests in the US and UK for the key building block technologies for the ZA2000 system, including cryogenic tanks and proprietary high-temperature PEM fuel cell and electric propulsion systems.
ZA2000 will support up to 80 seat regional turboprop aircraft such as the ATR72 or the Dash 8 400.
I was wondering what tanks Zero Avia is intending to use on its aircraft, and came across this:
https://www.verneh2.com/news-article/zeroavia-and-verne-partner-to-explore-cryo-compressed-hydrogen-for-airports-and-aircraft
Digging around:
'Cryo-compressed hydrogen is a cryogenic gas with a supercritical temperature. Gaseous hydrogen is compressed at around −233 °C where liquefaction does not occur. It is known to be a reliable option when it comes to storage and safety.'
https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://www.sciencedirect.com/topics/engineering/cryo-compressed-hydrogen&ved=2ahUKEwjGtICP_8uHAxXkU0EAHbzDCukQFnoECBwQAw&usg=AOvVaw2yv3oQGhI1tTfYCWlL8aJQ
So they use a double tank, under pressure, unlike liquid hydrogen.
The arguments for why that is inherently safe are bit above my head, but here is an analysis here, where BMW are looking at it:
https://www.h2tools.org/sites/default/files/ICHS_import/paper_143.pdf
AFAIK, liquid hydrogen on board is still Zero Avia's go to option, but it appears that cyrogenic tanks may have the advantage for hydrogen storage at the airport.
Posted by: Davemart | 29 July 2024 at 03:31 AM
It looks as though cryocompression is a lot more efficient than liquifaction, if I have managed to understand it correctly.
Posted by: Davemart | 29 July 2024 at 05:07 AM
Its not more efficient to cryptocompress, it just stores better without boil off.
Googliing turned up loads of summaries to articles I do not have full access to, and nothing directly to the point, so it can get a bit confusing!
Posted by: Davemart | 30 July 2024 at 01:07 AM
Engines are combustion Motors are electromagnetic to call these engines is wrong they are Motors turning propellers powered by fuel cells try to use the correct terms
Posted by: SJC | 30 July 2024 at 03:52 PM
Liquid H2 (LH2) is the lightest due to very light-weight container required, just a thin aluminum inner layer and a polyurethane foam insulation outside. The container weighs almost nothing.
Cold compressed H2 is next best in term of weight, because the pressure vessel can hold more H2 when it is cold than when it is at room temperature. At 160 degrees Kelvin, or -110 C, cold comressed H2 can hold 50% higher mass of H2 for the same weight of pressure vessel at room temperature. This is good for airplanes, trucks, and even passenger cars that will consume at least 1/3 of its H2 fuel content within half a day or so, or else, the fuel will be vented out as the tank will warm up to room temperature.
The best way to reduce the impact of the heavy fuel vessels would be to use the tanks as structural components of the vehicle to reduce structural weight required otherwise.
Cold compressed H2 would require much less energy and cost less to produce than LH2, but LH2 would be more appropriate for large airliners that require intercontinental range whereby the massive reduction in fuel weight can nearly double the payload per unit of fuel consumed.
Posted by: Roger Pham | 01 August 2024 at 12:56 PM
Hi Roger.
Have another look at the links on cold compressed hydrogen I have given, especially the BMW one.
For planes, they will use liquid H2 and light weight tanks, and also for trucks, as you don't have to have the hydrogen hanging around too long, as they have a job to do everyday.
In the unlikely atm at least event it was used in private cars, cold compressed would be a better choice, as it does not vent and you might not take the car out every day.
More realistically, for airports etc to fuel the planes, cold compressed tanks would seem to be a good choice, as they could hold the fuel indefinitely and swiftly top up the lightweight LH2 tanks in the planes.
I think that is how it works, at any rate, if I have understood the links correctly.
Posted by: Davemart | 01 August 2024 at 01:07 PM
So, for an H2 vehicle with 300-mi range with room-temp H2, if cold compressed H2 is to be used at 160 K, then the range would be increased to 450 miles, but it must use at least 150-mi during the 12 hours after fueling. So, 300-mi range for local driving, and 450-mi range for long-distance driving. It is not too energy intensive to chill the H2 down to 160 K (-110C) in comparison to LH2.
Posted by: Roger Pham | 01 August 2024 at 01:09 PM