"There's many a slip twixt the cup and the lip...". This could be the theme song for sustainable energy research - one so often reads a fascinating bit of news about this or that idea for new technologies, then those ideas seem to dissappear, only to be "rediscovered" on a few years later. So many good ideas and scientific findings and discoveries - but the developed and ready-to-use technologies always are just ten years out of reach.

So - good news, if true.

A grain of salt or two may be all that microbial electrolysis cells need to produce hydrogen from wastewater or organic byproducts, without adding carbon dioxide to the atmosphere or using grid electricity, according to Penn State engineers.

I've heard of Bruce Logan...

"This system could produce hydrogen anyplace that there is wastewater near sea water," said Bruce E. Logan, Kappe Professor of Environmental Engineering. "It uses no grid electricity and is completely carbon neutral. It is an inexhaustible source of energy."

Microbial electrolysis cells that produce hydrogen are the basis of this recent work, but previously, to produce hydrogen, the fuel cells required some electrical input. Now, Logan, working with postdoctoral fellow Younggy Kim, is using the difference between river water and seawater to add the extra energy needed to produce hydrogen.

Their results, published in the Sept. 19 issue of the Proceedings of the National Academy of Sciences, "show that pure hydrogen gas can efficiently be produced from virtually limitless supplies of seawater and river water and biodegradable organic matter."

Logan's cells were between 58 and 64 percent efficient and produced between 0.8 to 1.6 cubic meters of hydrogen for every cubic meter of liquid through the cell each day. The researchers estimated that only about 1 percent of the energy produced in the cell was needed to pump water through the system.

...

Logan and Kim's research used platinum as a catalyst on the cathode, but subsequent experimentation showed that a non-precious metal catalyst, molybdenum sulfide, had 51 percent energy efficiency.

Huh. What's the bacteria I wonder? Let's lok for the original article - hey there's some interesting looking articles in this thing... Proceedings of the National Academy of Sciences http://www.pnas.org/content/current

Here's the pdf of the Section with the PSU hydrogen article
http://www.pnas.org/content/104/47/18345.full.pdf+html?sid=4314f35b-3847-4593-866f-a11df46a95ef

The authors grew soil- or wastewater-derived bacteria in compact fuel cells modified
with ammonia-treated graphite granule anodes and an anion exchange membrane
(AEM). Ammonia treatment of the anodes increased bacterial adhesion, while the
AEM enhanced proton conduction, which
achieved high current densities. Using acetic acid, a common deadend
product of glucose fermentation, along with a small applied
voltage of 0.2–0.8 V, the reactor generated hydrogen gas to nearly
99% of the theoretical maximum yield. An additional advantage of
their microbial electrolysis cell is that sustainable hydrogen can be
produced at energy yields of up to 82% from any type of biodegradable
organic matter, including acetic acid, cellulose, and glucose.

So,, if I understand this right, this bacterial cell produces an electric current, OR (and?) it can produce gasses. I wonder how hard they are to build?