Hydrogen and ammonia are carbon-free fuels that, when combined in a blend, could play a key role in decarbonizing the energy sector.
That's why Texas Engineers are combining these two fuels, which are in many ways natural complements, as a potential source for generating carbon-free electricity. Fabrizio Bisetti and Noel Clemens, both faculty members in the Cockrell School of Engineering's Department of Aerospace Engineering and Engineering Mechanics, received a grant from the National Science Foundation to study the combustion of hydrogen/ammonia blends.
"A very large proportion of electricity worldwide is produced by fossil fuels," said Bisetti. "If we can tailor hydrogen/ammonia mixtures to have the same combustion properties as natural gas, the transition could be faster and less costly because one could use the same infrastructure with limited modifications to burn such carbon-free blends instead of fossil fuels."
The Work: The researchers plan to use both simulation tools and real-life experiments to better understand the combustion process of hydrogen/ammonia blends for large-scale power generation. The scientific community has plenty of information about hydrogen and ammonia separately, but together, knowledge is limited.
One well-known issue with both ammonia and hydrogen is that when combusted with air, they emit nitrogen oxides. Minimizing these emissions will be critical to the viability of these fuels as a sustainable power source and is a key goal of the project.
"A unique and exciting aspect of our project is that we'll be able to test and characterize hydrogen/ammonia combustion in a high-pressure combustion chamber at conditions that are very close to industrial applications," said Clemens.
Why It Matters: As Bisetti notes, fossil fuels are the backbone of electricity generation. They're also the sole fuel source in aviation. Because of the compact nature of airplanes, fuel sources with high energy density are needed.
If the researchers can fine-tune the hydrogen/ammonia blend combustion process to make it clean and as efficient as for fossil fuels, that could also lead to technology applicable to sustainable aviation. According to the International Energy Agency, aviation accounted for 2% of all global carbon emissions in 2022, and that number is growing faster than other parts of the transportation system, such as trains, shipping and road travel.
The Challenge: Hydrogen is seen as an important part of a clean energy future. However, because of its physical properties, its storage and transportation is difficult and costly. Ammonia stands out as a solution because it is easier to store and transport and naturally contains hydrogen atoms.
What's Next: In addition to the work simulating and testing the combustion of hydrogen/ammonia blends, the project features a public awareness component. The researchers are planning to develop a podcast centered around their work as well as the larger issue of power generation.
"We use electricity every minute of every day, but it's not top of mind how electricity is created, and the need for it to be generated sustainably," Bisetti said. "We hope this work will lead to more awareness and understanding of key issues in combustion-based electricity generation."