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

Methane

[LiquidCoooled]

I have been using microbes to produce methane for a while now, why can't I run my computer from that?

Need extra power for that long haul flight, just eat a curry before hand!

Slashdot articles ambiguous, rice says.

[rice_burners_suck]

I really love the way articles on Slashdot's front page have a tendancy to be written in such an ambiguous way that the reader learns nothing from the article. Behold this excerpt from the present article:

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.

It doesn't state how much hydrogen is produced. Are we discussing one molecule of hydrogen? (I know hydrogen is an element, but it floats around in the form of molecules.) And how much electricity is needed to power a cell phone? Are we talking about a fully-charged cell phone battery that becomes completely discharged? The description in this article doesn't tell you if:

• One hundred thousand megatons of hydrogen are produced by less energy than is required to power a cell phone for one nanosecond.
• One molecule of hydrogen is produced by less energy than is required to power a cell phone from the moment it is activated with a completely charged battery until the moment it shuts off because its battery becomes completely discharged.

This is what I love about Slashdot articles.

Re:Please use standard units

[Rosco P. Coltrane]

What is that in Libraries of Congress per Electronic Arts business day?

That's a silly unit: you know full well the Electronic Arts business day is an infinitely long time constant...

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. :-)

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.