GTL announces validation of LH2 tanks for aviation applications

Recognised for a strong history of transformational innovation in the aerospace industry, GTL President, Paul Gloyer, will share in-depth results from the successful validation testing of its small subscale composite vacuum jacketed dewar-tank with liquid hydrogen (LH2).

The GTL composite LH2 dewar-tank test results surpassed expectations. When fully isolated, GTL’s dewar-tank held hard vacuum at 2.8.e-6 torr for ~50 minutes with LH2, which was >100x better than the requirement. This allowed the GTL dewar-tank to hold LH2 for over 21 hours, at -430°F, while remaining leak tight with minimal hydrogen permeation. During this test, the subscale dewar-tank experienced only 2.8 watts of heat load. Based on this, GTL expects that the flight tanks will see only 1% LH2 boiloff per day.

Results showed the composite dewar-tank’s ability for rapid chill-down, paving the way for aircraft to be refuelled in minutes, vs waiting hours for a metal tank and transfer lines to cool. The inner composite tank went from ambient room temperature to 20°K (degrees Kelvin) and holding liquid hydrogen in less than 20 seconds and the GTL composite tubes achieved full LH2 flow in less than 1 second. The tests also show that no-vent fills of the composite dewar-tanks are achievable, which greatly improves refuelling safety.

“With these successful validation tests, we have achieved a critical milestone in aircraft decarbonisation. GTL is now proceeding with the fabrication of flight prototypes of the small composite LH2 dewar-tank. Our 28-in. diameter by 53-in. long flight-type tank weighs only 15 kg, including inner tank, outer vacuum shell, multi-layer vacuum insulation, internal tubing, and sensors, but can hold 19 kg of LH2.” said Gloyer.

This gives the GTL composite dewar-tank a hydrogen fraction (gravimetric index) of more than 55%, which is about 10x better than current hydrogen tanks. When stretched to carry 50 kg of LH2, the hydrogen fraction increases to over 62% with a mass of 30 kg, with larger versions able to achieve over 70% hydrogen fraction.

The GTL dewar-tank performance significantly exceeds the 35% hydrogen fraction goal needed for hydrogen to achieve parity with kerosene fuel (e.g., equal flight range). With GTL technology, hydrogen powered aircraft can exceed the performance of kerosene fuelled aircraft, while eliminating carbon emissions and reducing cost per passenger mile by more than 25%.

Read the article online at: https://www.globalhydrogenreview.com/hydrogen/14032024/gtl-announces-validation-of-lh2-tanks-for-aviation-applications/