While the “hydrogen economy” has been a promise for decades now, it's only lately that fuel cells have begun entering the commercial marketplace at a rapid clip. They are showing up in everything from cars to data centers and even supermarkets.
One of the remaining drawbacks to hydrogen fuels cells, though, was the fact that you still needed a process that required electricity to produce the hydrogen to power the fuel cell. Researchers at Penn State University may have solved that problem using – of all things – bacteria.
The new process, called microbial electrolysis cell (MEC), could produce fuel-cells that are essentially self-powered and therefore limitless in their ability to produce clean, emissions-free energy, reports the BBC.
“There are bacteria that occur naturally in the environment that are able to release electrons outside of the cell, so they can actually produce electricity as they are breaking down organic matter,” said the study's co-author, Bruce Logan. “We use those microbes, particularly inside something called a microbial fuel cell (MFC), to generate electrical power. We can also use them in this device, where they need a little extra power to make hydrogen gas. What that means is that they produce this electrical current, which are electrons, they release protons in the water and these combine with electrons.”
The energy generation would make use of a process called “reverse electrodialysis” or RED, which gathers the tiny bit of energy released when two samples of water, different in their salinity (salt content) meet one another through a thin membrane. The process generally uses a mixing of both saltwater and freshwater.
In their report, Professor Logan and co-author and colleague Younggy Kim say they envision an RED system that would use alternating stacks of membranes to harvest the energy. The movement of the charged atoms through the membranes from the saltwater to freshwater would create a small voltage that could be used or stored.
“If you think about desalinating water, it takes energy. If you have a freshwater and saltwater interface, that can add energy,” Professor Logan told the BBC. “We realized that just a little bit of that energy could make this process go on its own.”
The study's authors note that the process is in its infancy and therefore still too expensive for commercial applications, but they hope in the future the process will become feasible for generating a nearly endless supply of clean energy.
Professor Logan likened the process to any other alternative energy solution that had decades of baby steps before it became commercially available.
“Right now, it is such a new technology,” said Logan. “In a way it is a little like solar power. We know we can convert solar energy into electricity but it has taken many years to lower the cost. This is a similar thing: it is a new technology and it could be used, but right now it is probably a little expensive. So the question is, can we bring down the cost?”
Logan and Kim say they plan to try.
The research has been published in the Proceedings of the National Academy of Sciences.
Tracey Schelmetic is a contributing editor for TMCnet. To read more of Tracey's articles, please visit her columnist page.Edited by
Jennifer Russell
