Scientists at the Massachusetts Institute of Technology (MIT) have developed a new method to produce hydrogen fuel using seawater and coffee grounds.
MIT’s hydrogen production method can be applied to power engines or fuel cells in maritime vehicles, New Atlas reported on July 28. The new research was published in the journal Cell Reports Physical Science.
Two MIT researchers Aly Kombargi (left) and Niko Tsakiris (right) with the new hydrogen reactor. (Photo: Tony Pulson)
Hydrogen is a crucial element in the mission to decarbonize, as it burns cleanly, is energy-dense, and only emits water when used in fuel cells. However, a significant challenge is that hydrogen is difficult to store and transport because its tiny molecules tend to leak through containers and pipes. This not only leads to loss but also poses environmental risks from excess hydrogen in the atmosphere.
MIT’s new technology enables on-site hydrogen production. The only thing that needs to be transported and stored is aluminum, which is much more stable and easier to handle. In tests, a 0.3 g aluminum piece placed in deionized water produced 400 ml of hydrogen in just 5 minutes. When scaled up, the research team estimates that 1 g of aluminum could produce up to 1.3 liters of hydrogen. This is based on aluminum’s strong reaction with oxygen, which quickly strips O from H2O, allowing H2 to escape.
The research team treated the aluminum with a gallium and indium alloy, allowing the reaction to last longer. There is a downside, as gallium and indium are very rare and expensive, but the researchers found that conducting the reaction in an ionic solution causes the alloy to agglomerate into forms that can be collected and reused. Seawater serves as an ionic solution.
The next issue is that the reaction rate in seawater is very slow. The research team overcame this by adding coffee grounds, significantly reducing the reaction time from 2 hours to just 5 minutes. The key here is imidazole, a compound found in caffeine.
The reaction between aluminum and seawater produces hydrogen gas. (Video: MIT).
Experts believe that this new method lays the foundation for a practical hydrogen reactor that can power maritime vehicles. “This method is very exciting for maritime vehicles like boats or submarines, as there is no need to carry seawater. Seawater is always available“, said Aly Kombargi, the lead author of the study.
The first experiments will take place with a small underwater glider. The research team estimates that the vessel could operate continuously for 30 days by pumping seawater from the surrounding environment through a reactor containing about 18 kg of aluminum.
“We are demonstrating a new method for producing hydrogen fuel, without needing to carry hydrogen but instead carrying aluminum. Next, we need to figure out applications for trucks, trains, and potentially even airplanes. Perhaps instead of carrying water, we will extract water from the surrounding humidity to produce hydrogen,” Kombargi shared.
