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

The blurb doesn't mean much

[Rosco P. Coltrane]

The amount of electricity needed for the process is less than the amount required to power a standard cell phone.

To power what? A 100-gallon microbial fuel cell or a very teensy one?

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:Slashdot articles ambiguous, rice says.

[mchawi]

I agreed with your statement, but I thought I should check Google to see if I could find any information - just out of curiosity. At the time I posted this, I found 8 total articles. The thing that scared me even more was that all of the articles are similar in whole or in part. It looks like most of them probably just printed up a press release.

Does it scare anyone else how lazy our news media has gotten? Couldnt these people even make one phone call and try and add anything slightly new, different, or informative that everyone else doesn't have?

Sigh...

[Gorath99]

The amount of electricity needed for the process is less than the amount required to power a standard cell phone.

And what does that say? Nothing. I'm pretty sure I can create a couple of hydrogen molecules with that amount of electricity too and I won't even need any bacteria in the process.

Here's a more useful bit from the article, though it would be even more useful if they would just say what fraction of energy this process requires:

The voltage is just one-tenth needed for electrolysis - the process that uses electricity to break water down into hydrogen and oxygen.

Volt != Watt

[Tharkban]

Did the Volt turned into a unit of power while I was sleeping? And I thought I did well in physics.

Meaningless comparisons: "less than a cell phone"

[G4from128k]

The less than the amount required to power a standard cell phone statement is totally meaningless because it gives no indication of the efficiency of the process. Even at "0.25V", if the process requires tens or hundreds of electrons per molecule of hydrogen, then the process may be horribly inefficient. Even the "produces four times more hydrogen than would be typically generated by fermentation alone" is meaning less without some facts such as the molar conversion efficiency -- how many moles of hydrogen per mole of acetate does the augmented process create?

Moreover, this process is not the holy grail of pure electrolysis (e.g., splitting water into hydrogen and oxygen), it is an electrolyticly augmented chemical conversion of carbohydrates into carbon dioxide (green house gas), water, and hydrogen. In theory, this process could by part of a biomass-to-hydrogen fuel generation cycle, but as we have seen with ethanol production, the amount ethanol-based energy harvested is poor in comparison with the energy required to grow, reap, and process the plants (corn).

Don't get me wrong, this is a very intriguing finding, but there is far too little information in the article to determine if this process is thermodynamically better or worse than simply burning the carbohydrates in a furnace or standard combustion engine.

What frustrates and saddens me is that the analysis needed to make useful statements about this discovery are not that hard to make. Any competent chemist or chemical engineer could provide a useful back-of-the-envelop estimate of the energy inputs and outputs given an afternoon with the raw data from the experimenters. Either the scientists involved did not do this analysis (shame on them) or the journalists chose to ignore key results (shame on them) or the actual return on energy input is very poor indeed (to bad for all of us).

I hate articles that quote meaningless comparisons and leave the true question of practically total unanswered while holding out a vaporous promise that our energy problems are solved.