Scientists Use Microbes to Produce Hydrogen

An anonymous reader writes " Environmental engineers at Penn State University and a research scientist at Ion Power Inc. have created an electrically-assisted microbial fuel cell that can be used to produce hydrogen from organic material. The amount of electricity needed for the process is less than the amount required to power a standard cell phone. This advancement can be used to produce hydrogen as a byproduct of water treatment. " Coverage at ScienceDaily as well.

Comments

Re:YES!!!

[fyngyrz]

Probably not. Tap water contains all manner of stuff besides h2o. And since the hydrogen results from splitting the h from the o, that basically will leave you with a (tank|filter|general miasma/encrustation) of calcium, nitrates, bacteria, various metallic oxides, chlorine products and worse. The oxygen you might be able to use, but then again, maybe not.

You'll be splitting distilled water just like the rest of us, matey, and leave the tap water going down the drain. :-)

Re:Slashdot articles ambiguous, rice says.

[MojoRilla]

Complain about Slashdot all you want, but the articles and the original press release are all missing the details you want. This is a case where the only details that have been reported have been gleaned from a press release, only published two days ago. It will take a while before a journalist asks the kind of questions you want asked.

Slashdot is not a news site. There aren't a group of reporters doing fact checking. It is new aggregation and community site.

wanna see?

[xlyz]

here they are

read the full study

[xlyz]

pdf with the original paper here

Actual Paper Link

[cowtamer]

The actual paper referenced is Electrochemically Assisted Microbial Production of Hydrogen from Acetate by Drs Hong Liu, Stephen Grott, and Bruece E. Logan from Penn State, in the publication "Environmental Science and Technology."

Enjoy...

Re:Slashdot articles ambiguous, rice says.

[twelveinchbrain]

It doesn't state how much hydrogen is produced. Are we discussing one molecule of hydrogen?

According to the abstract:

This bio-electrochemically assisted microbial system, if combined with hydrogen fermentation that produces 2-3 mol H2/mol glucose, has the potential to produce ca. 8-9 mol H2/mol glucose at an energy cost equivalent to 1.2 mol H2/mol glucose.

ACTUALLY, BLURB is accurate! just think.

[goombah99]

A zillion posts here say that stating it uses 0.25v without stating the power used is meaningless. Well it's not. Well actually it's not what wou need to know. more on this in a second.

Hydrogen is produced when the bacteria exchanges a proton for an electron at the anode. The proton becomes the hydrogen.

thus it is one for one. For every hydrogen produced you have one electron dropping through a 0.25v external potential.

If other processes are also transferring protons then that's still hydrogen. So one electron passed means some proton contianing species ended up on the electrode. as long as you can make sure that those are mainly hydrogen and not some weird thing (say a metal or sodium or soduim), then you dont care.

So basically its a 0.25 volt cost atom produced.

Now to the numbers: One mole of electrons is the same as 96,500 Coulombs. So producing 96,500 would require about 25 kilo joules of energy. A mole of hydrogen, if I recall correctly, contains 280KJ of energy of which 230KJ is extracable as work (rest has to to to heat to pay the boltzman tax).

Of course the bacteria can also produce hydrogen on it's own. THe problem is the build up of reaction products that shut down the process. the current is used to help the bacteria get rid of these so the reaction can go to completetion producing hydrogen. Thus if I read this right in steady state we are indeed exchaning electrons for each hydrogen. The problem would then be if the bacteria is instead exchanging electrons for methane or something we dont want.

I cant quite figure out the abstract of the science paper but it sounds like they get about 80% of what they want.