Air travel has been inching towards decarbonization like a snail over two-sided tape, but the pace could pick up as Airbus follows through on its plan to develop hydrogen hubs at airports around the world. Not too long ago, that would involve a copious amount of fossil energy. However, Airbus has just inked an agreement with the global industrial gas firm Linde to help carry out its plan, and Linde has plans for juicing the green hydrogen supply chain.
Not-So-Green Hydrogen For The Airport Of The Future
In terms of soup-to-nuts decarbonization, the Linde deal could mean a couple of different things for Airbus’s global hydrogen hub plan, which is the aircraft builder launched back in 2020.
Hydrogen is not a 100% clean-burning fuel because nitrogen oxides are part of the emissions package. On the plus side, hydrogen only emits trace amounts of carbon dioxide when combusted. Also, when hydrogen is used in a fuel cell to generate electricity, there are no airborne emissions at all. Water is the only byproduct.
The problem is that the modern global economy runs on hydrogen sourced mainly through steam reforming, with natural gas as the primary feedstock. Coal and recovered industrial byproducts are also part of the picture.
Legacy firms like Linde have a solid footprint in fossil-sourced hydrogen, but they are also beginning to respond to customer demand for more sustainable sourcing. Carbon clamp-downs in a growing number of jurisdictions globally are also having an impact. Alongside its conventional hydrogen business, Linde also offers a hydrogen product certified as 40% less carbon-intense than the conventional steam method, deploying waste gases and other alternative feedstocks.
Demand For Green Hydrogen Is Rising
None of this sounds particularly attractive from a planet-saving point of view, but Airbus is one of those customers seeking more sustainable sourcing for hydrogen, and it is zeroing in on green hydrogen from renewable resources, which provides suppliers like Linde with all the more incentive to pursue more sustainable sourcing.
“Hydrogen is a high-potential technology with a specific energy-per-unit mass that is three times higher than traditional jet fuel. If generated from renewable energy through electrolysis, it emits no CO2 emissions, thereby enabling renewable energy to potentially power large aircraft over long distances but without the undesirable by-product of CO2 emissions,” Airbus enthuses (their emphasis).
At present, Airbus is considering two pathways for hydrogen in aircraft. Used as-is, hydrogen could be used as a combustible fuel in modified gas turbines, or it could be used to generate electricity in a fuel cell.
The other pathway is to hydrogen as a feedstock to produce new fuels, with carbon dioxide and an assist from renewable energy. That comes under the emerging category of electro-fuels, which are low-emission but not emission-free. As with biofuels, the idea is to recycle carbon rather than extracting carbon from the Earth.
More & Greener Hydrogen On The Way
Airbus expects to make a decision by 2025. Either way, the company expects green hydrogen to play a significant role in its hydrogen journey, and Linde appears to be prepping for a seat in the front row.
In January 2021, Linde announced that it will build a 24-megawatt electrolyzer at the sprawling Leuna Chemical Complex in Germany. Billed as the biggest of its kind at the time, the facility will provide green hydrogen to industrial customers through Linde’s existing pipelines. The company also announced plans to distribute liquefied green hydrogen in the region.
Linde is apparently on track to set the wheels in motion at Leuna sometime this year. Meanwhile, it is not letting the green hydrogen grass grow under its feet. In January of this year, the company announced plans for another 24-megawatt electrolyzer facility at Herøya Industripark in Porsgrunn, Norway, to supply hydrogen for a Yara ammonia plant. The idea is to demonstrate green hydrogen as a decarbonization driver for the fertilizer industry and maritime shipping industry, two areas of immediate interest to Yara.
What Is This Hydrogen Hub Of Which You Speak?
As for Linde’s role in the Airbus H2 hub plan, last week the two companies signed a Memorandum of Understanding that covers airports around the world, including a number of pilot projects to begin next year. The two companies will also collaborate on an assessment of electro-fuels.
Currently, airports in France, Italy, Japan, Singapore, and South Korea have signed on to the hub concept, which is initially aimed at integrating hydrogen into ground operations.
In support of the plan, last week Airbus also signed a Memorandum of Cooperation with Airports International Council Europe, aimed at enhancing “cooperation in the area of new aircraft energy ecosystems.”
“The joint goal is to enable the broader use of Sustainable Aviation Fuels (SAF) and to develop the hydrogen ecosystem required for the zero-emissions aircraft technologies, by preparing the associated airport supporting infrastructure and bringing these to market,” Airbus explains.
The Zero Emission Aircraft Of The Future
If all goes according to plan, the new hydrogen hubs will also service Airbus’s new hydrogen aircraft. The company unveiled its first “ZEROe” concept aircraft in 2020, showcasing hydrogen as “an option which Airbus believes exceptional promise as a clean aviation fuel and is likely to be a solution for aerospace and many other industries to meet their climate-neutral targets.” .”
Now would be a good time to place your bets on the winning concept:
“A turbofan design (120-200 passengers) with a range of 2,000+ nautical miles, capable of operating transcontinentally and powered by a modified gas-turbine engine running on hydrogen…
“A turboprop design (up to 100 passengers) using a turboprop engine instead of a turbofan and also powered by hydrogen combustion in modified gas-turbine engines, which would be capable of traveling more than 1,000 nautical miles…
“A “blended-wing body” design (up to 200 passengers) concept in which the wings merge with the main body of the aircraft with a range similar to that of the turbofan concept.”
Batteries Are Included
If you’re wondering if there is a battery-electric aircraft in Airbus’s future, that’s a good question. Airbus appears to be banking on hydrogen for scaled-up flight, but it has also been hammering away on intercity and regional travel thought its CityAirbus NextGen electric vertical take-off and landing aircraft.
Last week certainly was a busy week for Airbus. The company also announced a new agreement with Munich Airport International to provide ground infrastructure services and other support for the CityAirbus, which resembles a helicopter with fixed wings and a V-shaped tail instead of a top-mounted rotor.
Airbus has been gradually parceling out responsibility for developing parts of the CityAirbus, most recently KLM Motorsports for the tail and MAGicALL for the electric motors. So far no word on the battery, except they appear to be banking that the latest generation of lithium-ion batteries will be up to the task.
Hydrogen aircraft and battery-powered aircraft of any significant size are both still years in the offing, though both have been making headway. United Airlines, for one, is investing in the idea of battery-powered flight for short trips. It is also among the latest to hop aboard the fuel cell aircraft trend, in collaboration with the up-and-coming hydrogen fuel cell aircraft firm ZeroAvia. The US Navy is also eyeballing a solar-enabled fuel cell aircraft that could fly practically forever without refueling.
In the meantime Airbus, like other air industry stakeholders, is leaning on bio-based SAF to fill the gap. The company is already certified to fly on a blend of 50% bio-based SAF and 50% kerosene, and last year it began trialing 100% SAF from used cooking oil and other waste fat.
Follow me on Twitter @TinaMCasey.
Image: ZEROe concept aircraft courtesy of Airbus.
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