Hydrogen fuel cells could someday meet a host of industrial energy needs, but it's difficult and dirty to produce hydrogen using current methods. A new type of microbial fuel cell can power itself and produce a renewable supply of hydrogen, according to researchers at Penn State University. The system uses some seawater, some freshwater and bacteria.
It adds a water-based power supply to a microbial fuel cell, so there's no need for an external power source to augment the byproducts of microbial metabolism. Getting off the grid is a major breakthrough for fuel cell tech, according to the study's authors.
To provide extra power, Younggy Kim and Bruce Logan at Penn State used a reverse electrodialysis (RED) system, in which charged particles move in one direction through a membrane. Kim and Logan filled one chamber with seawater and another with freshwater. The salinity difference drives ions from the seawater side through an ion-exchange membrane to the freshwater side, which creates a voltage across the membrane.
The bacteria are placed on the freshwater side, where they munch on organic matter, releasing electrons as part of their metabolic processes. Combined with the energy from the RED system, the whole contraption produced enough voltage to break up water molecules into oxygen and hydrogen gas. The researchers called it a "microbial reverse-electrodialysis electrolysis cell."
"Individually, neither of these systems can accomplish hydrogen gas generation," the authors explain in a paper published in the Proceedings of the National Academy of Sciences. "The MEC requires an energy input (added voltage); and a small RED stack by itself cannot produce current."
As an added bonus, the bacteria used in this device can eat organic waste, so the system could conceivably be used for wastewater treatment, the authors said. Future prototypes could examine how flow rates would affect voltage production.
For now, however, the system is too costly to build to really make a difference in hydrogen production. Maybe someday.
Being a prototype and in development its promising technology. I look forward to this device in the future as it may become a cost effective hydrogen producing solution.
This is some pretty exciting stuff; hopefully someone with deep pockets can start scaling this up. Using waste water to power civilization is a brilliant concept not only for earth bound applications but interplanetary travel as well. On a side note, I guess we could refer to this as either green or brown energy depending on the day :)
Hydrogen is not dirty or difficult to produce. In fact the method of this article is dirtier than the normal method of simple electrolysis. The only dirty part of hydrogen production is the electricity source, which is coal for most folks. To me the "dirty" side of hydrogen is in the storage and quantities needed to be a viable energy source. Also in most cases of hydrogen fuel production you loose energy from what you put in initially.
"For now, however, the system is too costly to build to really make a difference in hydrogen production. Maybe someday."
Does that take into account the savings it could give the wastewater treatment facilities? If say this could make $10M per year in H2, but costs $15M per year to run, all it needs to do is save the wastewater treatment plants $5M per year and it's already worth building.
HAhaha "... produce hydrogen using current methods." I wonder if that was an intended pun.
Mantiss, the current industrial method for producing hydrogen gas is remarkably dirty. Electrolysis is a net-loss method (uses more power than the fuel it produces stores) and the electricity it requires is currently produced in the same much-maligned power plants that produces electricity for electric vehicles. Taking the process to an energy-neutral stage is a huge step.
you just repeated everything I said in my original post. Hydrogen can also be created with wind or solar, and not coal/nuclear. solar has a couple different tecniques to do by too.However, it is still a net loss of power, but it is portable!
Hydrogen today is not made by splitting water, but by stripping H2 from coal or other CH materials - thus it is cheaper (and dirtier) to produce H2 comercially than most think.
Nope. Sorry. No form of non-hydrocarbon energy will ever be used in any significant amount. The powers that be will never allow it. We will suck up every drop of crude oil and flatten every mountain top until there is nothing left and we go extinct. And the men running this could care less because they'll be dead by then.
This would be great in my town. Use the sewage treatment plants organics against a mildy hydrated saline or salt electrode