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Efficient method to capture carbon dioxide from the atmosphere

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Re: Efficient method to capture carbon dioxide from the atmosphere

#181

Post by mrspuratic »

nehal3m wrote: post #89
_yb2s wrote: post #67

Earlier quoted context omitted.

I think it’s little appreciated that high CO2 levels cause cognitive impairment, and with the same amount of (often very poor) air exchange, higher outdoor concentrations can push indoor spaces to levels that cause impaired cognition and poor sleep. I’ve already been seeing this in my home, and will often open windows even when cold just to keep co2 levels reasonable. One solution that can help is an external air hea…

>One solution that can help is an external air heat exchanger I have one of those, it blows fresh air in through the bedroom and sucks it back out through the kitchen (loft house, this route prevents food smells from wafting into the bedroom). Aside from just feeling fresh all year, this system also prevents mosquitoes from entering in summer while still allowing air circulation, it automatically bypasses the exchang…

This. I have that type (regenerative MHVR) installed in the attic for upstairs, and a synced pair of in-wall ceramic (recuperative) types on opposite sides of main living area downstairs (eliminating ducting, albeit with reduced efficiency). I haven't attempted any energy/ROI calculations but fresh filtered air, lower humidity and good nights sleep are well worth the claimed single-digit watt power usage to me.

Re: Efficient method to capture carbon dioxide from the atmosphere

#182

Post by mikestorrent »

nine_k wrote: post #144
LargeWu wrote: post #137

Earlier quoted context omitted.

I've wondered if capturing carbon emissions from industrial-scale compost facilities would be a net positive. It would have the added benefit of the carbon initially being captured by natural organic processes (i.e. growing food), so it avoids the problem of the energy requirements from trying to just pull carbon from the ambient atmosphere. I don't know if this is feasible but I haven't seen any research on it.

What we need to offset the last 3 centuries of coal use is to reverse the process. Plant large amounts of trees, cut them, burn the hydrogen part of them, producing char and reclaiming some energy, then bury the resulting coal back in the abandoned coal mines.

> burn the hydrogen part of them

Could you elaborate

Re: Efficient method to capture carbon dioxide from the atmosphere

#183

Post by lefra »

dheera wrote: post #32
gus_massa wrote: post #6

Earlier quoted context omitted.

I agree. Plants are not very efficient (1% or 2%) but they include packaging the CO2 in a stable form. You can store the grain or wood for long periods of times. In this case, it looks like they get CO2 as a gas. It's cheaper because you don't have to use energy to undo the burning, but it's difficult to store for a long time. (I'm not sure if someone tried to make a fake underground bog in abandoned mine. Just fill…

> stable form Not really, forest fires happen and then a few hundred of years of sequestered CO2 gets released back in an instant. Organic material with oxygen gas floating around is not stable. Sequestering carbon into the ocean might be a better strategy. Not flammable and not subject to stupid capitalism effects around land prices.

The ocean has already absorbed 30% of the CO2 humanity has emitted. It causes issues: ocean acidity rises, which reduces plankton ability to grow. Plankton being the base of the ocean food chain, all ocean life gets impacted.

You'd need to find a way to sequester carbon without it leaching in the water.

https://marine.copernicus.eu/ocean-climate-portal/ocean-carb...

Re: Efficient method to capture carbon dioxide from the atmosphere

#184

Post by akshatjiwan »

jmward01 wrote: post #114

I am not against doing research in this area, please do, it is interesting and likely has many applications but global CO2 removal isn't one of them. Nothing proposed, including this, is within any orders of magnitude of a viable solution. The only solution we have is put less in the air in the first place. This tech looks interesting for transporting CO2 but that doesn't mean it sequesters it and even if sequestrati…

I think you have a point. It could be difficult to justify the cost of carbon capture based on sequestration alone. One of the reasons I think this might still work is that captured carbon can be used to create platform chemicals (various hydrocarbons) using the fischer tropsch process. Electrofuels are using direct air capture to generate fossil replacements.

Only requirement is energy and there too it isn't all that expensive to pull air in from the atmosphere or to seperate CO2 from adsorbent via low grade heat (70-100c)

So far into the future this method could allow us to continue produce critical hydrocarbon materials (used everywhere from plastics to pharamaceuticals) without having to depend upon concentrated and contested oil supplies.

More than energy efficiency its volumetric efficiency that's the issue. At the moment (to the best of my knowledge) kg of capturing materials capture tens of grams of CO2. Pulling it from air is not that energy intensive but finding materials that can actually filter out CO2 from that air is difficult. If breakthroughs are made in this area it will have industrial applications. Then it won't be just sequestering.

Of course the easier solution is to plant more trees and grasses but they grow very slowly and require valuable land. Still this approach is feasible in some uncultivable lands. Crops like cottongrass[1] can grow even in tundra climate and can be valuable source of both technically imp carbon via cellulose and a means to capture CO2. We don't have to make a choice. We can do both simultaneously.

[1] https://www.fs.usda.gov/database/feis/plants/graminoid/eriva...

Re: Efficient method to capture carbon dioxide from the atmosphere

#185

Post by TSiege »

nine_k wrote: post #117
jmward01 wrote: post #114

I am not against doing research in this area, please do, it is interesting and likely has many applications but global CO2 removal isn't one of them. Nothing proposed, including this, is within any orders of magnitude of a viable solution. The only solution we have is put less in the air in the first place. This tech looks interesting for transporting CO2 but that doesn't mean it sequesters it and even if sequestrati…

Sequestering CO2 where it's highly concentrated, e.g. at power plants or cement factories exhausts, would be one way to emit less.

This is called Carbon Capture and Storage and so far it has never been worth it energetically. And the only companies doing it are oil companies in a process known as enhanced recovery which pushes more co2 out than is pushed in. The OP was right. Better to leave it in the ground

Re: Efficient method to capture carbon dioxide from the atmosphere

#186

Post by amelius »

jmward01 wrote: post #114

I am not against doing research in this area, please do, it is interesting and likely has many applications but global CO2 removal isn't one of them. Nothing proposed, including this, is within any orders of magnitude of a viable solution. The only solution we have is put less in the air in the first place. This tech looks interesting for transporting CO2 but that doesn't mean it sequesters it and even if sequestrati…

You might think it is silly to do this, but what if carbon emission trading makes this profitable?

Re: Efficient method to capture carbon dioxide from the atmosphere

#187

Post by teknopaul »

nine_k wrote: post #117
jmward01 wrote: post #114

I am not against doing research in this area, please do, it is interesting and likely has many applications but global CO2 removal isn't one of them. Nothing proposed, including this, is within any orders of magnitude of a viable solution. The only solution we have is put less in the air in the first place. This tech looks interesting for transporting CO2 but that doesn't mean it sequesters it and even if sequestrati…

Sequestering CO2 where it's highly concentrated, e.g. at power plants or cement factories exhausts, would be one way to emit less.

I think OPs point is this tech is good only if you sink it after.

I. e. Collection is half the problem.

Collecting it in a way it's cheap to get it back again is potentially just less than minus half the problem.

Re: Efficient method to capture carbon dioxide from the atmosphere

#188

Post by Retric »

amelius wrote: post #186
jmward01 wrote: post #114

I am not against doing research in this area, please do, it is interesting and likely has many applications but global CO2 removal isn't one of them. Nothing proposed, including this, is within any orders of magnitude of a viable solution. The only solution we have is put less in the air in the first place. This tech looks interesting for transporting CO2 but that doesn't mean it sequesters it and even if sequestrati…

You might think it is silly to do this, but what if carbon emission trading makes this profitable?

That’s like asking what happens if gravity reverses, the answer is irrelevant because the situation is not going to happen.

Re: Efficient method to capture carbon dioxide from the atmosphere

#189

Post by thinkcontext »

mixedbit wrote: post #142
jmclnx wrote: post #41

Earlier quoted context omitted.

I agree, plus were would one store the CO2 ? To get back to "1980", I really doubt puling CO2 from the atmosphere will ever work. Another concern, who will pay for maintenance ? See this for why you cannot let CO2 escape from underground storage: https://en.wikipedia.org/wiki/Lake_Nyos_disaster If stored near a populated area, hundreds of thousands could be kill, including all animals and insects, in a matter of minu…

Can't we just store C and let the O2 back in the air like plants do? We could store it right where it came from, in old coal mines.

Chemical reduction of CO2 is a very hard problem since it takes a lot of energy. There's an enormous amount of research in this area. Storing it costs money, so most of the research focuses on turning the C into a useful product.

https://en.wikipedia.org/wiki/Electrochemical_reduction_of_c...

Re: Efficient method to capture carbon dioxide from the atmosphere

#190

Post by teknopaul »

ctoth wrote: post #124
jmward01 wrote: post #114

I am not against doing research in this area, please do, it is interesting and likely has many applications but global CO2 removal isn't one of them. Nothing proposed, including this, is within any orders of magnitude of a viable solution. The only solution we have is put less in the air in the first place. This tech looks interesting for transporting CO2 but that doesn't mean it sequesters it and even if sequestrati…

> If we don't have the political will to reduce the amount going into the air then what makes anyone think we would have the political will to build out some system to capture and sequester? Because political will requires coordination, building systems and turning them on doesn't have to! > We need to focus more on not putting CO2 into the air and less on trying to take it out. What part of the "we" in this coordina…

The is one trick that doesn't require political will. If you can make the microeconomics work it can be made to scale it self.

E.G. Make CO2 extraction so cheap it's worth everyone doing it and say, make a market to sell the CO2 to farmers. Then make burying inedible bits of plants so cheap it's done on a large scale.

Then you just wait. Microeconomics takes over.

They did this with plastic clean up. By building a machine that makes plastic into fuel & construction pellets. Then stuck such a machine on a plastic poluted island and waited.

For this trick. All you require from your políticans is that they don't lie or bomb the place.

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