Why can't we just suck out carbon from the atmosphere?

[fishfood5388]

Hi, Im new to this site and this topic but I understand sucking carbon out of the air and converting it to a solid has been talked about before and the limitations being that it costs a lot of energy. Is there a study about that I can learn about more? Or could someone elaborate on the feasibility and constraints of this? Thanks!

[John Cuthber]

The biggest single problem is that there's not much CO2 in the air.

At 400 ppm (by volume), each tonne of air only contains about 600 grammes of CO2.

So you need to shift huge volumes of air, and that takes a lot of energy.

 

[swansont]

There has been discussion of doing this at the exhaust of devices that use fossil fuels, where the concentration is much higher than the ambient atmospheric value.

Such as https://www.acs.org/content/acs/en/pressroom/presspacs/2012/acs-presspac-january-4-2012/new-materials-remove-co2-from-smokestacks-tailpipes-and-even-the-air.html

Still can potentially be energy intensive, if you are stripping the Carbon from th Oxygen, but you aren't having to move huge volumes of air about.

[Strange]

A number of ways of doing this have been proposed, some quite high-tech and others using more "natural" processes. A summary of a few here: https://www.bbc.co.uk/news/science-environment-45967215

But it seems it may not be effective enough, even if it could be done: https://www.scientificamerican.com/article/sucking-co2-from-the-air-would-not-halt-effects-of-global-warming/

Then there is the problem of what to do with the captured CO2. Unless it can be sequestered for a very long time (probably thousands of years, at least) then it isn't really solving the problem.

This system captures CO2 and uses it to grow vegetables: https://www.sciencemag.org/news/2017/06/switzerland-giant-new-machine-sucking-carbon-directly-air

Firstly, I am sceptical that providing CO2 to plants will greatly improve yields (for some plants it has the reverse effect).

Secondly, once those plants are consumed (and the non-edible parts composted) a large part of the CO2 will be returned to the atmosphere.

[naitche]

The ideas touched on in the 1st article linked by Strange, along with changes in current farming practices  suggest that moving away from monocultures and treating farm lands as diverse  ecosystems  can have very large impacts on carbon sequestration.

Interesting results in carbon sequestration have been achieved, along with better water retention, soil fertility microbial action and more by mimicking the effects of migratory herds. Conservation grazing is becoming recognised as a tool for for better land management. 

Industrialised farming practices appear to be a huge contributor to desertification, and the ability of soils to retain carbon. 

Edited August 27, 2019 by naitche

[fishfood5388]

Thanks for the links to the articles!   I looked at what other things we could do with the carbon aside from feeding it to plants and many of the articles suggested we could pump it back into the earth but the drawback is it could leak.

This article I found suggests there is material that converts co2 to solid carbon which would be easier to store underground reliably, https://cosmosmagazine.com/chemistry/scientist-turn-carbon-dioxide-into-coal-at-room-temperature

 

[Airbrush]

On 8/25/2019 at 6:03 PM, fishfood5388 said:

Hi, Im new to this site and this topic but I understand sucking carbon out of the air and converting it to a solid has been talked about before and the limitations being that it costs a lot of energy. Is there a study about that I can learn about more? Or could someone elaborate on the feasibility and constraints of this? Thanks!

Here is how to suck co2 out of the air.  Transport huge amounts of sea water to deserts near the ocean.  Fill thousands of concrete ponds to a few feet deep.  Cover the ponds with transparent, convexly-lensed glass that you make from desert sand.  These magnify the sunlight to create water vapor that condenses into fresh water to be transported by individual hoses to trees.  No water is wasted.  The trees grow and capture the co2 for hundreds or thousands of years.  These oases can spring up anywhere in the world, and can grow larger over time.  Making more and more fresh water, and planting more and more trees.

[CharonY]

There is a big push for carbon capture and storage technologies, but so far AFAIK there is no real option that is more sustainable than alternatives (such as use of plants for carbon storage). The most efficient methods include capture at point of emission, which could have some use to mitigate industrial release. Some, are already in use for quite some time (at least the capture part, storage is a bit more iffy). In industrial use methods such diethanolamine treatment or selexol are in use, but they are not generally not feasible post-emission. There are efforts to push monoethanolamine capture as means to do that, but I am not sure how sustainable that method is. Last thing I hear was a rather mixed bag.

[John Cuthber]

I saw a cartoon of a guy who said he made a solar powered device that extracted CO2 from the air and produced building material as a by product.

The guy he was talking to asked to see it.

The first guy pointed at a tree.

The problem is finding land where we could plant them.

[Airbrush]

16 hours ago, John Cuthber said:

I saw a cartoon of a guy who said he made a solar powered device that extracted CO2 from the air and produced building material as a by product.

The guy he was talking to asked to see it.

The first guy pointed at a tree.

The problem is finding land where we could plant them.

Plant them in deserts.  Water them with desalinated sea water.

[dimreepr]

2 minutes ago, Airbrush said:

Plant them in deserts.  Water them with desalinated sea water.

Deserts aren't very furtile, besides the logistics of your plan is very, very limited; especially when we have to ship in organic material as well.

[Airbrush]

11 minutes ago, dimreepr said:

Deserts aren't very furtile, besides the logistics of your plan is very, very limited; especially when we have to ship in organic material as well.

How can we produce large amounts of fertilizer (without using petroleum)?  How about sea weed, algae, or fish?  You can grow plants hydroponically, can you grow trees that way?

Maybe some of the fresh water is used to grow plants that only need fresh water, desert sand, and a few cheap, liquid nutrients.  Then those plants can be used to fertilize trees.

Edited September 4, 2019 by Airbrush

[dimreepr]

1 minute ago, Airbrush said:

How can we produce large amounts of fertilizer (without using petroleum)?  How about sea weed?  You can grow plants hydroponically, can you grow trees that way?

Maybe some of the fresh water is used to grow plants that only need fresh water, desert sand, and liquid nutrients.  Then those plants can be used to fertilize trees.

I'm not saying it's not possible, not even that it shouldn't be done; I'm saying it's not the solution, at best it's a very small part of the solution

[CharonY]

There is a fair bit more than just water and fertilizers to growing plants, I imagine. And there are probably better places than deserts available to do so. Optimistic estimates have stipulated that massive tree-planting programmes might sequester as much as one third of the required CO2 reduction to hit the proposed limits of the Paris accord.

However, other researchers have found additional factors that paint a much more complex picture. Some forests, may for instance promote the emission of methane and nitrous oxide. Others argued that large-scale reforestation may actually have an overall mixed effect with uncertainty about net benefits. Still most would think that reforestation has a net benefit, but the magnitude is very much unclear.

[John Cuthber]

7 hours ago, dimreepr said:

Deserts aren't very furtile, besides the logistics of your plan is very, very limited; especially when we have to ship in organic material as well.

Why bother?
https://en.wikipedia.org/wiki/Hydroponics

 

7 hours ago, Airbrush said:

Water them with desalinated sea water.

Desalination is horribly energy intensive.

[Airbrush]

On 9/4/2019 at 1:18 PM, CharonY said:

There is a fair bit more than just water and fertilizers to growing plants, I imagine. And there are probably better places than deserts available to do so. Optimistic estimates have stipulated that massive tree-planting programmes might sequester as much as one third of the required CO2 reduction to hit the proposed limits of the Paris accord.

Where would be a better place for large-scale solar-desalination and tree-planting than a desert that is not far from the ocean?   Such deserts are considered wastelands for most purposes.  Water and nutrients can be piped from the ocean.  Glass, for transparent, lensing, covers on the concrete ponds, is made from desert silica.

[dimreepr]

11 hours ago, Airbrush said:

Where would be a better place for large-scale solar-desalination and tree-planting than a desert that is not far from the ocean?   Such deserts are considered wastelands for most purposes.  Water and nutrients can be piped from the ocean.  Glass, for transparent, lensing, covers on the concrete ponds, is made from desert silica.

Why not cover the desserts with solar panels and use the generated energy to desalinate the oceans and then pipe the water to a more productive area; or just do what Costa Rica did.

[Airbrush]

2 hours ago, dimreepr said:

Why not cover the desserts with solar panels and use the generated energy to desalinate the oceans and then pipe the water to a more productive area; or just do what Costa Rica did.

I looked at your Costa Rica example and there is no mention of solar panels to gather energy to desalinate sea water.  Am I missing something?

Would using solar panels be more efficient, or cheaper, than using sea water ponds covered with convexly-lensed glass to heat water?  Any opinions from the experts on power generation?  Is it more costly to build solar desalination ponds than to use that land for solar panels?

[dimreepr]

5 minutes ago, Airbrush said:

I looked at your Costa Rica example and there is no mention of solar panels to gather energy to desalinate sea water.  Am I missing something?

Yes, they planted trees where trees tend to grow; without the need to direct our available energy in a pointless direction...

Edited September 6, 2019 by dimreepr

[Airbrush]

It may be a pointless direction to plant trees in the desert.  Certainly plant trees where there is already rain to water them.  Plant trees everywhere you can.  It is not enough to stop dumping greenhouse gases into the atmosphere.  We should also try to remove co2.  I am still waiting for an expert on power generation to tell if direct solar-desalination is not a better use of desert wasteland than using solar panels to power a traditional desalination plant.

IF large numbers of trees could be grown in desert regions, would that change the local weather so that there would be rain where there was no rain before?  The trees may be watered with desalinated water, AND occasional desert rain storms created by tree respiration.

With climate change causing rising sea levels, coastal dwellers will be forced inland where they will encounter inlanders who will fight over their land.  Not far off we will see wars over land, water, and other resources.  If population centers could be self-sufficient, by means of direct solar-desalination, they could exist anywhere on the planet.  They would not need to be in conflict with other population centers.  They would not be confined to coastlines, or other traditional water sources, such as rivers or lakes.

Edited September 6, 2019 by Airbrush

[dimreepr]

4 minutes ago, Airbrush said:

But I am still waiting for an expert on power generation to tell if solar-powered desalination is not a better use of desert wasteland than using solar panels to power a desalination plant.

I'm no expert, but that very much depends on a need for desalinated water over a need for energy...

[Airbrush]

2 minutes ago, dimreepr said:

I'm no expert, but that very much depends on a need for desalinated water over a need for energy...

Generally, I would think water is needed over energy.  Civilization needs both.  Surviving in the wild you need water first, and later maybe you can also generate a little energy.

[dimreepr]

4 minutes ago, Airbrush said:

Generally, I would think water is needed over energy.  Civilization needs both.  Surviving in the wild you need water first, and later maybe you can also generate a little energy.

I'm guessing, you don't live in manchester. 

[naitche]

Forrests are being planted in deserts,with some very promising results. Not always requiring piped in water either. 

In the middle east, the Sahara, China Ethiopia and more.

Research has shown solar panels and low growing plants can be compatible, increasing wattage  output through cooling the panels and depending on the plants chosen, can improve water efficiency and yield of plants.

Sewerage could be a low cost, readily available fertilizer.

It may be costly, but essential if land degradation is to be halted or reversed. Less costly by far to those on site and dependent on the land, providing an income and increasing soil fertility and water retention/available ground water.

Having trouble loading links and no time to try again but they are easy to find

I'm thinking solar panels over (smaller farm)  Dams could also benefit in some instances.

 

 

 

 

[naitche]

On 9/4/2019 at 6:00 AM, John Cuthber said:

I saw a cartoon of a guy who said he made a solar powered device that extracted CO2 from the air and produced building material as a by product.

The guy he was talking to asked to see it.

The first guy pointed at a tree.

The problem is finding land where we could plant them.

Private family owned farms around the world are being reduced to subsistence due to land degradation (that increases with pressures to compete with corporate owned farms) and climate change effects. Informed plantings can reverse that in most instances, and increase income- But carbon taxes add to the subsistence levels makng those improvements often out of reach to the land that  would benefit.

Maybe a fund could be set up, for  contributions from those with no where to plant but wish to,  to supply the means for those with the land but lacking  materials.

Fertiliser and plants supplied, If it could be done without some middleman looking to profit.