Extract CO2 from air

[Mosquito]

Hi, just a quick question, in case anybody here has any easy knowledge on this.

I have thought a little about extracting CO2 from the air and pushing it to plants as a way of

a) getting some plants to grow faster
b) doing a little to reduce the growing levels of CO2 in the atmosphere

a) is the most realistic feature of this, of course.

The question is about how to do this? Is it a dumb idea? Would it require prohibitive amounts of energy to extract the CO2?

Ideally, the added CO2 would make the plants grow faster/better so that it actually paid off doing this. And since I've never heard of anybody doing it, there may very well be good reasons for not doing it.

And yes, I know there are some pretty simple/cheap ways of generating CO2, but I was thinking of getting it from the air or possibly from water. (Preferrably from air.)

Actually, just increasing the amount of CO2 a bit would probably be enough, I do not have any knowledge of how plants react to high concentrations of CO2.

Mosquito - just curious

(Actually, a bit lazy too, but some lurker might like the question, now that it has been asked)

 

[casebro]

Isn't that the gist of one guy's reasoning behind dumping iron ore into the oceans? The iron will cause an algea bloom, that will soak up tons of CO2. Not much iron needed either. Dropped from airplanes, like fire bombers, or ships as they traverse???

Ought to be something googleable.

 

[Orangutan]

Carbon Dioxide is only 0.038% of the air. Carbon dioxide is usually generated for crops by burning gas and trapping the results of the combustion. So it's not really reducing the levels of C02.

 

[meg]

How big a scale are you talking about? Plants/crops outside? Or in a closed environment, like a greenhouse? Or smaller?

 

[Ziggurat]

I have thought a little about extracting CO2 from the air and pushing it to plants as a way of

a) getting some plants to grow faster
b) doing a little to reduce the growing levels of CO2 in the atmosphere

a) is the most realistic feature of this, of course.

The question is about how to do this? Is it a dumb idea? Would it require prohibitive amounts of energy to extract the CO2?

It would require too much energy to do on a commercial scale. In terms of a), the benefits aren't dramatic. In terms of b), there are better options: namely, if you work with the exhaust from a coal-fired power plant, you're dealing with mostly CO2 from the beginning, no concentration required. People are indeed looking at ways of taking this exhaust and capturing the CO2 in some way - one method under investigation is to pipe it deep underwater, so that it dissolves into the ocean.

 

[a_unique_person]

Taking the exhaust from CO2 creating machines is called carbon sequestration. It is only in the experimental stage, and many doubt it's viability.

 

[DRBUZZ0]

Hi, just a quick question, in case anybody here has any easy knowledge on this.

I have thought a little about extracting CO2 from the air and pushing it to plants as a way of

a) getting some plants to grow faster
b) doing a little to reduce the growing levels of CO2 in the atmosphere

a) is the most realistic feature of this, of course.

The question is about how to do this? Is it a dumb idea? Would it require prohibitive amounts of energy to extract the CO2?

Ideally, the added CO2 would make the plants grow faster/better so that it actually paid off doing this. And since I've never heard of anybody doing it, there may very well be good reasons for not doing it.

And yes, I know there are some pretty simple/cheap ways of generating CO2, but I was thinking of getting it from the air or possibly from water. (Preferrably from air.)

Actually, just increasing the amount of CO2 a bit would probably be enough, I do not have any knowledge of how plants react to high concentrations of CO2.

Mosquito - just curious

(Actually, a bit lazy too, but some lurker might like the question, now that it has been asked)

Extracting it from the air would probably not be useful, given the low contration. You can get CO2 relatively cheaply from any compressed gas supplier. (it's used in paint ball guns, soda machines...lots of stuff).

You could also toss in some dry ice.


I recall a while ago hearing about some experiments to pipe some of the CO2 from an oil refinery (obviously CO2 from relatively clean processes) into a series of greenhouses. I think it did help with plant growth quite a bit.

It was just a little pilot program though...not really anything to generate major crops. Might be interesting though.

Just be careful. Being in a greenhouse full of CO2 is not good for people.. So you may want some sort of measuring device. Also, plants do need some degree of oxygen, especially at night. (they produce it, but also will consume a little). So if you displace all the oxygen by pumping in a big stream of CO2, that might not be good either...

 

[Mosquito]

Isn't that the gist of one guy's reasoning behind dumping iron ore into the oceans? The iron will cause an algea bloom, that will soak up tons of CO2. Not much iron needed either. Dropped from airplanes, like fire bombers, or ships as they traverse???

Ought to be something googleable.

I am aware of this option, it may be the best available, even for my "purposes" (which are basically just curiosity-satisfaction).

I suppose this could be done in a way so as to be able to harvest the algea in order to pay for the project?

Mosquito - algea-burning powerplants next?

 

[Mosquito]

How big a scale are you talking about? Plants/crops outside? Or in a closed environment, like a greenhouse? Or smaller?

This would probably have to be closed in, so that the gas does not escape. A greenhouse should be excellent. Unless the "iron in the ocean"-option is much better, that is.

Mosquito - would be nice if it could produce food...

 

[Mosquito]

It would require too much energy to do on a commercial scale. In terms of a), the benefits aren't dramatic. In terms of b), there are better options: namely, if you work with the exhaust from a coal-fired power plant, you're dealing with mostly CO2 from the beginning, no concentration required. People are indeed looking at ways of taking this exhaust and capturing the CO2 in some way - one method under investigation is to pipe it deep underwater, so that it dissolves into the ocean.

Taking the exhaust from CO2 creating machines is called carbon sequestration. It is only in the experimental stage, and many doubt it's viability.

Of which I read that it would be much cheaper to get it at the source (which sounds rather logical), but that it is not necessarily viable?

The benefits of getting it directly from the air would also include things like no need for transport. Doesn't make it better if the costs of extraction are much higher though.

As far as I know, buying CO2 is rather cheap?

Mosquito - thinking "big scale" algea sounds better and better

 

[Mosquito]

Extracting it from the air would probably not be useful, given the low contration. You can get CO2 relatively cheaply from any compressed gas supplier. (it's used in paint ball guns, soda machines...lots of stuff).

You could also toss in some dry ice.


I recall a while ago hearing about some experiments to pipe some of the CO2 from an oil refinery (obviously CO2 from relatively clean processes) into a series of greenhouses. I think it did help with plant growth quite a bit.

It was just a little pilot program though...not really anything to generate major crops. Might be interesting though.

Just be careful. Being in a greenhouse full of CO2 is not good for people.. So you may want some sort of measuring device. Also, plants do need some degree of oxygen, especially at night. (they produce it, but also will consume a little). So if you displace all the oxygen by pumping in a big stream of CO2, that might not be good either...

The amount of extra plant growth would have to pay for the project. I don't know how much extra growth to expect. 2% is not much... 100% could be rather interesting (making some wild guesses here).

This experiment sounds like a good place to look for information on this though. I'll try to get some google-time later.

It sounds very similar to my idea, sans the oil refinery, which is somewhat outside my budget.

Mosquito - Time to work a little again

 

[DRBUZZ0]

Here's some info about one of the projects using refinery gasses: http://environment.guardian.co.uk/food/story/0,,1851332,00.html

http://www.dw-world.de/dw/article/0,2144,2214482,00.html


here's some info about CO2 enrichment products geared to the greenhouse gardener:

http://homeharvest.com/carbondioxideenrichment.htm

 

[Loss Leader]

I've designed an experiment to see if extra CO2 will even have any effect on plants. You need a bottle of soda, a hose, a plastic shopping bag and a growing plant. Put the bag over the plant, snake in the hose, attach the other end to the soda and shake. This should fill the bag with CO2, surrounding the plant. Then leave it like that for, say, two hours. Repeat every day for a month. Set up a control plant with a bag filled with normal air. Take measurements. Enter grade school science fair.

Let me know if you win.

 

[DRBUZZ0]

I've designed an experiment to see if extra CO2 will even have any effect on plants. You need a bottle of soda, a hose, a plastic shopping bag and a growing plant. Put the bag over the plant, snake in the hose, attach the other end to the soda and shake. This should fill the bag with CO2, surrounding the plant. Then leave it like that for, say, two hours. Repeat every day for a month. Set up a control plant with a bag filled with normal air. Take measurements. Enter grade school science fair.

Let me know if you win.

Don't ruin the soda!

Actually...if you want some CO2 for such an experiment a better idea would be to seal the plant in a bag and then inflate it with CO2 by putting some vinigar in a container and dropping in some baking soda then quickly sealing the bag and allowing them to reach, producing CO2 in the process.

 

[Capsid]

I've designed an experiment to see if extra CO2 will even have any effect on plants. You need a bottle of soda, a hose, a plastic shopping bag and a growing plant. Put the bag over the plant, snake in the hose, attach the other end to the soda and shake. This should fill the bag with CO2, surrounding the plant. Then leave it like that for, say, two hours. Repeat every day for a month. Set up a control plant with a bag filled with normal air. Take measurements. Enter grade school science fair.

Let me know if you win.

The experiment has been done at least for promoting plant growth in aquarium systems. So the idea of increasing algal growth in the sea is not without some precedent. Then again, algal blooms can be harmful.

ETA: Also if you wish to reduce CO2 then it's best to plant trees which will lock up the carbon from the C02 as wood.

 

[RecoveringYuppy]

Just be careful. Being in a greenhouse full of CO2 is not good for people.. So you may want some sort of measuring device. Also, plants do need some degree of oxygen, especially at night. (they produce it, but also will consume a little). So if you displace all the oxygen by pumping in a big stream of CO2, that might not be good either...

Plants need virtually the same level of oxygen as animals and are poisoned by similar concentrations of CO2 as animals. In addition to photosynthesis, plants share the same respiration mechanism as animals. They "burn" glucose and oxygen in to CO2 and water using the same mechanisms we do.

 

[Mosquito]

Plants need virtually the same level of oxygen as animals and are poisoned by similar concentrations of CO2 as animals. In addition to photosynthesis, plants share the same respiration mechanism as animals. They "burn" glucose and oxygen in to CO2 and water using the same mechanisms we do.

This sounds wrong... So I've got to ask for evidence on this.

If plants need about the same level of oxygen as animals, where does the oxygen come from? How is it being replenished? This goes against the lies-to-children of my school years.

I think humans consume about 20% of the oxygen in each breath, converting it to about 4%CO2, though this is from memory, so it could be wrong. If this is typical for plant life on this planet, the atmosphere should have a noticably lower amount of O2 after a short while...

Also, what is "animal" in this context? Some animals seem to be able to live quite well on the O2 dissolved in water, and that is substantially less than 20%, isn't it?

I also imagine cold-blooded animals need much less O2 than warm-blooded animals? Some manage on the oxygen they can absorb through the skin, this can't be anywhere near as efficient as breathing.

Slow/docile animals needing less than hyperactive little buggers?

And plants are typically very docile-looking (and I know some are rather aggressive, but it takes a lot of time for them to battle it out, so it should not need much energy), so they should not need all that much?

Are there any numbers?

Mosquito - smelling a rat

 

[Mosquito]

Here's some info about one of the projects using refinery gasses: http://environment.guardian.co.uk/food/story/0,,1851332,00.html

http://www.dw-world.de/dw/article/0,2144,2214482,00.html


here's some info about CO2 enrichment products geared to the greenhouse gardener:

http://homeharvest.com/carbondioxideenrichment.htm

Thanks!

Very interesting, seems to be giving a significant yield increase and better economics, and they only went to about a doubling of CO2, wonder what would happen it CO2 was increased to about 1%? Or more (it should be possible to do this by replacing nitrogen rather than oxygen so as to allow for survivable oxygen levels)...

Mosquito - finding that part the idea is not dumb, though getting the CO2 directly from the air does not seem like a good idea.

 

[DeviousB]

If plants need about the same level of oxygen as animals, where does the oxygen come from? How is it being replenished? This goes against the lies-to-children of my school years.

[...]

And plants are typically very docile-looking (and I know some are rather aggressive, but it takes a lot of time for them to battle it out, so it should not need much energy), so they should not need all that much?

Are there any numbers?

Sorry, that's quite a snip in the middle there.

Plants get their oxygen from their immediate environment. Under adequate daylight their oxygen needs are more than met by O₂ from photosynthesis and the net is released to the atmosphere. At night or in poor light, plants take O₂ from the atmosphere.

Typically, plants will consume between ¹/₄ and ³/₄s of their entire photosynthetic output in respiration.

Source: Plant Respiration - From Cell to Ecosystem (ISBN 1-40203588-8)

 

[RecoveringYuppy]

If plants need about the same level of oxygen as animals, where does the oxygen come from? How is it being replenished? This goes against the lies-to-children of my school years.

They get it from the atmosphere and from air bubbles in the soil. It's replenished by plants. Plants have both photosynthesis and respiration going on. Nearly all life forms large enough to see are eukaryotes. They all have mitochondria to carry out respiration (oxidation of glucose).

I think humans consume about 20% of the oxygen in each breath, converting it to about 4%CO2, though this is from memory, so it could be wrong. If this is typical for plant life on this planet, the atmosphere should have a noticably lower amount of O2 after a short while...

That would depend on how much the plants are returning via photosynthesis. However I didn't comment on the quantity plants consume, I was talking about the level or the the ratio. Plants don't need much since they don't move and aren't warm blooded. But the percentage they need in the atmosphere is virtually the same as animals. They use less, yes. But the chemical reactions in the mitocondria operate over virtually the same ratios of atmospheric composition in both animals and plants. Plants are going to suffer greatly at 10% CO2 the same way we do (CO2 at 10% become poisonous to most eukaryotic life regardless of how much oxygen is present. "Dead zones" in the ocean free of oxygen are fatal to both animals and plants).

Also, what is "animal" in this context? Some animals seem to be able to live quite well on the O2 dissolved in water, and that is substantially less than 20%, isn't it?

20% of a gas and 20% of a liquid is an apples and oranges comparison. But I would think that animals and plants in the water derive approximately the same mass of oxygen from the water as similarly active animals/plants on land.

Some links from "+plant +respiration" at Google below. Lot's of others available.

http://photoscience.la.asu.edu/photosyn/books/Lambers-PlantRes-Bk.html

http://www.spacesciencegroup.org/sootw/Default.asp?Theme=plants&pagename=plantrespiration