MIT researchers innovate hydrogen fuel with seawater

Researchers from the Massachusetts Institute of Technology (MIT) are pioneering a method to produce hydrogen fuel using recycled materials—specifically, aluminum from old soda cans—as well as seawater and a dash of caffeine. This innovative approach has the potential to pave the way for a more sustainable and efficient energy system, particularly for marine applications.

The core of this technique hinges on a simple chemical reaction where aluminum reacts with seawater to generate hydrogen gas. MIT team demonstrated that by exposing pure aluminum pellets to seawater, they could produce hydrogen without harmful carbon emissions. To complement this reaction, they discovered that adding coffee grounds accelerates the process, thanks to an active compound found in caffeine called imidazole.

This development is particularly exciting because hydrogen fuel is known for being clean-burning, energy-dense, and safe. When used in fuel cells, the only byproduct of hydrogen combustion is water. However, a significant challenge in utilizing hydrogen fuel has been its storage and transport. Conventional methods involve carrying high-pressure hydrogen tanks, which can be risky due to the gas’s volatility and leak potential.

The MIT team’s novel approach means that instead of transporting hydrogen, vehicles would only need to carry aluminum pellets as fuel. This approach reduces risks and complications associated with hydrogen transport. By leveraging seawater—which is readily accessible in marine settings—fuel production can occur on demand, minimizing the need for excess cargo.

Prior to this discovery, researchers struggled with the ‘oxide barrier’ challenge—aluminum quickly forms aluminum oxide when exposed to air, stalling the reaction. To combat this, the MIT team pre-treated aluminum pellets with an alloy of gallium and indium, which helps to break down this oxide layer. The result? A sustained reaction that can generate substantial amounts of hydrogen relatively quickly.

During initial experiments, the team noted that immersing a single aluminum pellet (3 grams) in fresh de-ionized water could yield up to 400 milliliters of hydrogen in just five minutes. Under the less reactive conditions of seawater, the reaction takes longer, originally up to two hours—but the addition of coffee grounds significantly decreased this time back to five minutes.

This research not only provides a creative use for aluminum waste, a form of recycling that addresses both ecological and energy crises, but it also showcases a robust step toward sustainable energy solutions. The team is currently focused on developing a small reactor designed for marine vessels. This reactor will contain aluminum pellets and enough gallium-indium and caffeine to sustain the hydrogen-producing reaction.

The researchers project that such a system could power an underwater glider for roughly 30 days, relying on the surrounding seawater for hydrogen production. Moving forward, they aim to explore further applications of this method, potentially extending it to trucks, trains, and even airplanes.