UCF Group strives to revolutionize the aviation industry with green emissions fuel

Green-fueled planes could soar into blue skies in the future as a University of Central Florida research group takes off with experimental fuel and equipment to revolutionize the aviation industry.

Earlier this year, the group won a five-year, $10 million NASA grant to create its environmentally friendly ammonia fuel and jet engine components capable of running it. The grant came just months after President Joe Biden’s administration set a goal of achieving net-zero greenhouse gas emissions from the U.S. aviation sector by 2050.

Aviation is one of the world’s top 10 emitters of greenhouse gases and responsible for almost 5% of the impact of global warming on Earth, according to the Climate Action Network. Airplanes release greenhouse gases and water vapor into the atmosphere, contributing to global warming reactions, CAN reported.

It’s a problem that has grown considerably worse, with emissions from international aviation increasing by 54% between 1990 and 2015.

Emissions are expected to increase by 4.3% per year over the next 20 years. Adding fuel to the fire is that industry emissions are outstripping efficiency improvements. This growing problem poses a threat to the Paris Agreement’s climate change goals, prompting the president to find a solution within the next three decades.

“It’s realistic, but it’s going to be extremely difficult,” said Jay Kapat, principal investigator and professor of engineering at UCF. “Aviation is a very difficult sector to decarbonize, as it requires a certain type of fuel and a certain type of power supply which, due to weight and volume, imposes limits on an aircraft.”

Leading the team, Kapat is responsible for thermal management and system integrations, but he is not alone in his efforts. Several UCF faculty and students will also work on the project in partnership with entities such as Georgia Tech, Purdue, GE and Boeing. The team will use a Boeing 737-8 class as the baseline for its experiments since it accounts for nearly a quarter of all commercial aircraft, according to Boeing.

The idea is simple: replace the aviation industry’s standard fuel source, kerosene, with ammonia.

UCF researchers keep several factors in mind, such as availability. Whatever the energy solution proposed by the group, it must be accessible worldwide.

“Every airport and every aircraft should have a significant upgrade cost that is not prohibitive. If it did, it would never be implemented,” he said.

This is what led UCF researchers to ammonia, which is widely available as a necessary ingredient in most fertilizers.

However, as things stand, ammonia wouldn’t be as effective as a fuel source as kerosene, but it potentially offers other great benefits. For example, kerosene is a huge producer of nitrogen oxides (NOx) – which are greenhouse gases – in its exhaust gases. Reducing kerosene exhaust NOx levels to negligible levels is not possible, Kapat said.

“On the other hand, ammonia can do that,” he said. “Power companies already use ammonia to remove the NOx they produce.”

So if ammonia can be used as a fuel source, why not use the leftover ammonia to erase its own carbon footprint?

“If we use ammonia as [energy] to power the plane anyway, we can use some of that ammonia, keep it extra and use it to remove NOx,” he said.

Additionally, the group wants to use the exhaust from a jet and convert the heat emitted into electricity in a process called the “supercritical carbon dioxide cycle.” The UCF houses a “test loop” that will be used to experiment with optimizing heat transfer.

In the current state of current engines, heat is otherwise wasted when it could be used as additional power for on-board instruments. Current jet designs include generators that extract mechanical energy from spinning rotors and convert it into electricity.

“It’s power extraction that could have been used for actual propulsion,” Kapat said.

The conversion process also provides cooling, which can be used to prevent engines from overheating and burning out.

While the benefits are intriguing, researchers must also overcome the hurdle of finding the optimal combination of ammonia and hydrogen in a combustor. UCF will use a unique instrument, known as the short tube, to hone its chemical knowledge and learn the best way to control combustion and fly the jets.

NASA’s UCF grant is just to start the first phase of testing. The whole project will require future funding and will likely take up to 15-18 years. Either way, Kapat is hopeful for the project’s future and is meeting the president’s 2050 deadline. Although Kapat is reminded that to create real change, global accessibility will be needed.

“Everything is difficult if we do not take into account the real cost. And the cost is not just money, or a monetary cost, but the cost is also the way we do things,” he said, also mentioning that vast global changes need to be made in order to to decarbonize the industry. “It’s doable but a lot of things have to happen first.”


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