In a groundbreaking discovery, the Massachusetts Institute of Technology (MIT) suggests that old soda cans and seawater could be the key to revolutionizing fuel production and creating a sustainable source of clean energy. MIT engineers have discovered that when pure aluminum from soda cans is exposed to seawater, it creates bubbles and naturally generates hydrogen. This type of gas can be used to power an engine or fuel cell without producing carbon emissions. Furthermore, this basic reaction can be accelerated by including a common stimulant: caffeine.
The Model
In a study published in the journal ‘Cell Reports Physical Science’, the researchers show they can produce hydrogen gas by dropping pretreated, pebble-sized aluminum pellets into a beaker of filtered seawater.
The aluminum is pretreated with a rare-metal alloy that effectively scrubs aluminum into a pure form that can react with seawater to generate hydrogen. In a sustainable cycle, the salt ions in the seawater can attract and recover the alloy, which can be reused to generate more hydrogen. The team found that this reaction between aluminum and seawater successfully produces hydrogen gas, though slowly. On a lark, they tossed some coffee grounds into the mix and found, to their surprise, that the reaction picked up its pace.
In the end, the team discovered that a low concentration of imidazole — an active ingredient in caffeine — is enough to significantly speed up the reaction, producing the same amount of hydrogen in just five minutes, compared to two hours without the added stimulant.
Maritime Applications
The researchers are also developing a small reactor that could run on a marine vessel or underwater vehicle. The vessel would hold a supply of aluminum pellets (recycled from old soda cans and other aluminum products) and a small amount of gallium-indium and caffeine.
These ingredients could be periodically funneled into the reactor and some of the surrounding seawater to produce hydrogen on demand. The hydrogen could fuel an onboard engine to drive a motor or generate electricity to power the ship.
“This is very interesting for maritime applications like boats or underwater vehicles because you wouldn’t have to carry around seawater — it’s readily available,” study lead author Aly Kombargi, a PhD student in MIT’s Department of Mechanical Engineering, said. “We also don’t have to carry a tank of hydrogen. Instead, we would transport aluminum as the ‘fuel,’ and just add water to produce the hydrogen that we need.”
The MIT team, led by Hart, is developing efficient and sustainable methods to produce hydrogen gas. Hydrogen gas is seen as a “green” energy source that could power engines and fuel cells without generating climate-warming emissions.
One drawback to fuelling vehicles with hydrogen is that some designs require the gas to be carried onboard like traditional gasoline in a tank—a risky setup, given hydrogen’s volatile potential. Instead, Hart and his team have looked for ways to power vehicles with hydrogen without constantly transporting the gas. They found a possible workaround in aluminum — a naturally abundant and stable material that undergoes a straightforward chemical reaction that generates hydrogen and heat when in contact with water.
