White Yeti
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Simplest way to convert electrical energy to food.
Hello,
I've pondered this question for quite some time, so I figured I'd ask the community.
I know you can break down glucose and lipids through a series of catalysed steps to generate an electric current, but I was wondering how the opposite
could be done.
I know you can turn electrical energy into chemical energy very easily, splitting water being one example. But how would you go about making more
complicated substances, like carbohydrates (or any other substance that higher organisms can use for energy) from carbon dioxide and water? Plants do
this all the time, but how would you design a semi-artificial machine that would get the same job done, except that uses electrical energy as an input
and yields high energy molecules as an end product. I say semi-artificial because I don't want to exclude the use of primitive organisms which can
catalyse certain chemical reactions without needing high temperatures, pressures and expensive catalysts.
I figured a good place to start would be to use acetogenic bacteria which can convert hydrogen gas (produced though electrolysis) and carbon dioxide
into water and acetic acid:
2 CO2 + 4 H2 → CH3COOH + 2H2O
But what now? How would you convert this precursor to something with a higher energy density like glucose or a saturated fatty acid, something a
higher organism can process with ease?
Since anabolic reactions are endergonic, it becomes more and more problematic to perform them with the aid of bacteria, since high entropy and low
energy are favoured, the bacteria would break the molecules down. It would be interesting if the calvin cycle could be run, but you'd need a way if
turning electrical energy into ATP from ADP. This gets really messy from a feasibility standpoint.
I'm not sure how feasible it is to transfer electrons from an anode to an electron carrier, such as NADP+, but it might be a more direct way to
artificially synthesise large organic molecules. Then with the aid of hydrogenase enzymes, you could hydrogenate carbon dioxide without
phosphorylating it with ATP.
Ultimately, the final result would be a machine that could sustain life without using the sun as an energy source, since electricity can be generated
from fission energy. A closed loop system where carbon dioxide and water are recycled and serve as energy storage media.
Any thoughts?
"Ja, Kalzium, das ist alles!" -Otto Loewi
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RonPaul2012
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This may not have anything to do with your post but I seem to remember that you can convert cellulose into sugar with HCL , or perhaps it was starch
into lower sugars.
I'm not sure but this is a great post and deserves some input better than what I can provide.
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[Edited on 7/9/13 by bfesser]
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Poppy
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There was light
I think maybe recreate the life the process would definitely come back over the start.
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bfesser
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I don't mean to drag this thread off topic, but I must mention that we already convert electricity into food on a massive industrial scale. It's
called the <a href="http://en.wikipedia.org/wiki/Haber_process" target="_blank">Haber–Bosch process</a> <img
src="../scipics/_wiki.png" />. Without this process, we wouldn't be able to grow enough food to feed the human population of modern Earth. This
process eats up somewhere around 1% of our energy supply; a huge figure, yet we hardly notice.
[Edited on 7/9/13 by bfesser]
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crazyboy
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Sunlight or an artificial light source can be used to grow phytoplankton, which can be fed to krill. Phytoplankton should be relativly easy to farm,
they need water and CO2 as well as macronutrients such as nitrates, phosphates, potassium, iron, and magnesium and other micronutrients. The krill
could be eaten alone, fed to feed stock or processed further. I doubt that farming either is a particularly efficient use of space, so it wouldn't be
very viable for a space vessel or a primary colony.
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stygian
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CO2 is electrolytically reduced to formaldehyde, converted to sugars via formose reaction 
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White Yeti
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Quote: Originally posted by crazyboy  | | Sunlight or an artificial light source can be used to grow phytoplankton, which can be fed to krill. Phytoplankton should be relativly easy to farm,
they need water and CO2 as well as macronutrients such as nitrates, phosphates, potassium, iron, and magnesium and other micronutrients. The krill
could be eaten alone, fed to feed stock or processed further. I doubt that farming either is a particularly efficient use of space, so it wouldn't be
very viable for a space vessel or a primary colony. |
I agree, this would definitely not be an option for colonists on the moon or some other planet, but I think it's the future for providing food here on
earth. The problem with the sea is that phosphates and other nutrients sink to the bottom for detritivores and trolls to feed off of. If we find ways
to bring these nutrients back to the surface where phytoplankton can use them to grow, we could use the sea as farmland. Upwelling happens naturally
in some places where ocean currents switch direction, but we could artificially get nutrients to the surface as well. If you ask me, this definitely
beats those hippie ideas for growing food in towers. The sea is the most neglected resource on the planet. People don't realise that the sea is not
just for commercial fishing and throwing trash into.
@stygian, I don't mean to be critical, but do you have a paper of some kind to substantiate your claim? I can't seem to find anything on the subject
on the interwebs.
"Ja, Kalzium, das ist alles!" -Otto Loewi
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RonPaul2012
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| Quote: Originally posted by bfesser | | I don't mean to drag this thread off topic, but I must mention that we already convert electricity into food on a massive industrial scale. It's
called the <a href="http://en.wikipedia.org/wiki/Haber_process" target="_blank">Haber–Bosch process</a> <img
src="../scipics/_wiki.png" />. Without this process, we wouldn't be able to grow enough food to feed the human population of modern Earth. This
process eats up somewhere around 1% of our energy supply; a huge figure, yet we hardly notice. |
Holy sh!t
that's a lot of energy ; I had no idea
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[Edited on 7/9/13 by bfesser]
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White Yeti
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It might be a large amount of energy, but it's still peanuts (legume pun intended) compared to the amount of energy consumed when crops are transported from the farm to the grocery store, and the petroleum that goes into the
plastic in packing and such.
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[Edited on 7/9/13 by bfesser]
"Ja, Kalzium, das ist alles!" -Otto Loewi
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stygian
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I find it hard to believe you can't find on google anything about reduction of CO2, or the formose reaction
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White Yeti
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Finding documentation on the formose reaction is no problem.
I also know carbon dioxide is reduced in plants by a process requiring NADPH and enzymes, but I've never heard of the same process being carried out
in a lab setting.
I found one book on the subject, but the methods described were far too complex to implement to any extent. The more chemicals used, the more can go wrong.
The fact that you are reluctant to post links to documentation that substantiates your claim shows that you're speculating rather than describing a
truly useful method.
<!-- bfesser_edit_tag -->[<a href="u2u.php?action=send&username=bfesser">bfesser</a>: removed
unnecessary quote(s)]
[Edited on 7/9/13 by bfesser]
"Ja, Kalzium, das ist alles!" -Otto Loewi
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stygian
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I never said it would be useful, easy, efficient, or anything of the sort. I also find it hard to believe that carbohydrates are all thats required
to sustain life.
Buuuut, that/those syngas-fermenting organisms come to mind. Ethanol certainly has the food calories you're seeking.
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ScienceSquirrel
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Thread Pruned
13-3-2012 at 05:09 |
h2o2guru
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The Haber–Bosch process doesn't use much "Electricity" Almost all the energy comes from burning and reforming natural Gas "Methane".
One neat method of using electricity to "make" food , that I came across is to Grow Iron bacteria for food . Iron bacteria get ALL of there metabolic
energy from reducing iron. You can recharge the iron and grow the iron bacteria inside a electrolytic cell . this is actually the best way to get a
rich culture of iron bacteria. I saw a NASA blurb about using this technology for Space food, but haven't found any papers yet.
Some Iron bacteria even fix nitrogen , so you just need some trace elements.
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AJKOER
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| Quote: Originally posted by White Yeti | | Quote: Originally posted by crazyboy | | Sunlight or an artificial light source can be used to grow phytoplankton, which can be fed to krill. Phytoplankton should be relativly easy to farm,
they need water and CO2 as well as macronutrients such as nitrates, phosphates, potassium, iron, and magnesium and other micronutrients. The krill
could be eaten alone, fed to feed stock or processed further. I doubt that farming either is a particularly efficient use of space, so it wouldn't be
very viable for a space vessel or a primary colony. |
I agree, this would definitely not be an option for colonists on the moon or some other planet, but I think it's the future for providing food here on
earth....
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Actually, there could be a great need in the future right here on earth for substitute sunlight. For example, in the event of a significant volcanic
eruption (I recall hearing that such an event occurred about 10,000 years ago, confirmed per the limited diversity of DNA for existing humans on
earth, that was responsible for the reduction of all human life to near extinction level), that block out the sun for an extended period (years?).
First the plants died followed by animal life and finally humans that relied on both. Meteors can have a similar effect.
How soon we forget.
[Edited on 15-3-2012 by AJKOER]
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White Yeti
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These events are extremely rare. By the time that happens, we would have colonised the moon and other celestial bodies. So if our civilisation manages
not to destroy itself first, we could survive a volcanic eruption or a meteor impact no problem.
"Ja, Kalzium, das ist alles!" -Otto Loewi
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