Fuel cells may soon be powered by hydrogen harvested from people’s pee
As hydrogen fuel cells become a more common way to power our world, the idea of filling up your tank may take on a few new connotations. These power plants capture energy from the reaction of hydrogen bonding with oxygen, and while amazingly clean, they still require some raw materials on hand to function. Hydrogen is abundant in our universe, and oxygen is literally floating in front of your face right now, but capturing these ingredients in a form that’s usable isn’t always easy. The U.S. Army Research Laboratory has been working on how to simplify this supply chain, and may have found a very convenient source of hydrogen in the form of soldiers’ pee.
Making use of human urine wasn’t the project’s original point of interest, but has turned out to be so efficient that researchers can’t ignore its promise. They had originally been working with water and a nano-galvanic aluminum powder, which, when added to water would cause a reaction where one of the products was pure hydrogen. A few different water-based liquids were tested, and pee was found to perform twice as well straight H2O. Researchers haven’t narrowed down the secret to urine’s success, but think may be tied to the higher acidity and presence of electrolytes.
Portable power sources
If researchers do figure out why pee is such a good hydrogen producer, they’re not looking to alter that side of the formula. While the aluminum-based powder may still be refined, the goal of this project was to enable soldiers to generate power in remote locations. Researchers estimate that as little as two pounds of aluminum powder could yield enough hydrogen to produce 220 kilowatts of electricity, which is enough to fully charge up nine Nissan Leafs. As long as carrying the powder isn’t a problem, soldiers could then provide the necessary hydrogen by recycling other fluids, including the pee a healthy body creates anyway. To really close the loop on this supply chain, soldiers could then drink the clean water a fuel cell produces as a byproduct, getting them ready to top off their generators later on.
My kids said: Ew. That’s gross! Wouldn’t the water be like pee water?
Nope. The urea and other stronger smelling ingredients in the pee would be totally left behind in this processes first step. The water molecules from the pee would be effectively destroyed before even entering the fuel cell, and so the water byproduct at the end wold be pure water with no adulterants. It’d be safe to drink, although you presumably do have a dried out pile of urine ingredients after extracting the hydrogen from it.
Source: Army scientists discover power in urine by David McNally, United States Army Research Laboratory