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We need to take CO2 out of the sky – an overview of climate tech

orbuch.com

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Re: We need to take CO2 out of the sky – an overview of climate tech

#61

Post by cs02rm0 »

AncientTree wrote: post #60

My biggest concern about CO2 is the cognitive impact it has on humans - at levels 800ppm and higher, mental performance is impacted. It will take a while for the atmosphere to reach this level (hopefully it never does), but it is common inside houses and offices. As atmospheric CO2 rises, it becomes more difficult to ventilate buildings, and human mental performance degrades. In terms of geoengineering, it seems like…

Have you got a reference for the 800ppm bit? Not being provocative - it'd be genuinely useful to me.

Re: We need to take CO2 out of the sky – an overview of climate tech

#62

Post by matco11 »

orbuch wrote: post #41
ComputerGuru wrote: post #28

What the article leaves to the conclusion is what needs to be stated up front and center: it's virtually impossible to do this efficiently, cheaply, or effectively because there's so little CO2 in the air, meaning a) adding even a little bit more greatly affects the CO2 levels b) with a global ppm of ~400, it basically means that you need to filter 2500 molecules of air to get a single molecule of CO2, and that's ass…

(I wrote the post) This is good feedback that this is buried in the appendix -- I pulled that section up and made it inline with the flow of the post. Does that help?

Yes, it does.

GREAT work.

Two (small) comments: - Perhaps the review of the re-forestation option could mention that this has a number of positive side effects (outside of carbon capture), for example on rainfall and wildlife.

- as there is a time constraint on co2 capture (e.g. 2050), and as the various co2 capture solutions are not all at the same stage of maturity, it could be useful to have a table/chart that summarizes which co2 capture options are deployable now vs. at some stage in the future

Re: We need to take CO2 out of the sky – an overview of climate tech

#63

Post by avmich »

orbuch wrote: post #57
avmich wrote: post #50

Earlier quoted context omitted.

Section "How to take CO2 out of the sky" > Briefly: there are plant-based, mineral-based, and chemical options. Where are cryocooling-based options?

I'm not sure what this is? You might be thinking of solar radiation management or other "geoengineering" techniques to try to make the earth shiner and reflect more sunlight, making us cooler at a constant CO2 concentration. Theres a ton of interesting topics within that to write about, I mention it briefly as "things I didn't include"

No, the idea is something similar to this - https://sesinnovation.com/ .

You carefully compress incoming air. Separate water vapors (and liquids, and hopefully not solids) from it. Cool this air in thermal exchanger - at this point CO2 falls off. Then you pass that air through turbo detander, which returns you some energy, and get a pre-liquified air, which pass to the thermal exchanger. Clean air of normal temperature is released to atmosphere.

You have to compress the air - but you also cool air, so compression is easier, and you also get some energy from the turbine where you decrease the pressure. Subject to optimizations. How much energy will you need?

Re: We need to take CO2 out of the sky – an overview of climate tech

#64

Post by avmich »

foxhill wrote: post #59
orbuch wrote: post #57

Earlier quoted context omitted.

I'm not sure what this is? You might be thinking of solar radiation management or other "geoengineering" techniques to try to make the earth shiner and reflect more sunlight, making us cooler at a constant CO2 concentration. Theres a ton of interesting topics within that to write about, I mention it briefly as "things I didn't include"

having not read the article (yet), i the OP is referring to “cooling down air until it liquifies then using fractional distillation to pull out the CO2”?

You don't want to do unnecessary transformations, to preserve as much energy as possible (so the turbine, which is needed for cooling, should work on small pressure difference). So, no air liquification - just let CO2 separate and send cleaned air back to the heat exchanger.

Re: We need to take CO2 out of the sky – an overview of climate tech

#65

Post by throwaway8941 »

cs02rm0 wrote: post #61
AncientTree wrote: post #60

My biggest concern about CO2 is the cognitive impact it has on humans - at levels 800ppm and higher, mental performance is impacted. It will take a while for the atmosphere to reach this level (hopefully it never does), but it is common inside houses and offices. As atmospheric CO2 rises, it becomes more difficult to ventilate buildings, and human mental performance degrades. In terms of geoengineering, it seems like…

Have you got a reference for the 800ppm bit? Not being provocative - it'd be genuinely useful to me.

https://en.wikipedia.org/wiki/Carbon_dioxide#Below_1%

Re: We need to take CO2 out of the sky – an overview of climate tech

#66

Post by [deleted] »

privateSFacct wrote: post #37
ComputerGuru wrote: post #28

What the article leaves to the conclusion is what needs to be stated up front and center: it's virtually impossible to do this efficiently, cheaply, or effectively because there's so little CO2 in the air, meaning a) adding even a little bit more greatly affects the CO2 levels b) with a global ppm of ~400, it basically means that you need to filter 2500 molecules of air to get a single molecule of CO2, and that's ass…

It only has to do it cheaply now because there is NO COST to putting CO2 into the air. Why are people surprised that if something is free (pumping CO2 into air) demand for it is high? You are telling me that doing a charge of let's say $10 - $100/ton of CO2 wouldn't have a DRAMATIC impact on emissions? Is $10 - $100/ton too little for a supposed climate emergency? There is so much funding and lawmaking and finger poi…

[deleted]

Re: We need to take CO2 out of the sky – an overview of climate tech

#67

Post by stouset »

avmich wrote: post #56
mdorazio wrote: post #40

Earlier quoted context omitted.

I had the same thought as well. It's an option, but the energy required to cool air to the precipitation point of CO2 (-79C) is pretty large, and the cooling process itself will produce greenhouse gas, so you end up with a pretty small return.

How do you calculate how much energy is required? You would use cooled separated products to pre-cool incoming stream of "dirty" air. CO2, having low concentration, won't fall off at -79C (or we'd have that effect in Antarctica today), but if you go to ~-140C, you'll have some results. Why cooling process will produce greenhouse gas? You'd use energy from "green" sources to compensate for required expenses.

> You’d use energy from “green” sources…

This isn’t something you can just assert as if by magic.

By using this kind of technology, you increase the total power requirements of our civilization. That power has to come from somewhere. If you earmark green energy sources for it, something else will need to use a dirty energy source.

This remains true as long as green energy production falls short of planetary demand (modulo carbon taxes/credits/caps which change the math here a bit depending on specifics). The leftover slack will be met by burning fossil fuels.

Re: We need to take CO2 out of the sky – an overview of climate tech

#68

Post by jdsully »

mdorazio wrote: post #40
avmich wrote: post #34

Earlier quoted context omitted.

> There is no magic powder we can mix that'll cause CO2 to precipitate out of the atmosphere and fall to the ground like snow; it's a grueling energy intensive process to filter that out of the air around us. Why not to cool down air so that CO2 would fall off? Cooled air can be used for pre-cooling incoming "dirty" air stream?

I had the same thought as well. It's an option, but the energy required to cool air to the precipitation point of CO2 (-79C) is pretty large, and the cooling process itself will produce greenhouse gas, so you end up with a pretty small return.

Antartica is -56C right now. Another 23C should be manageable. This doesn’t have to be done in the tropics.

Re: We need to take CO2 out of the sky – an overview of climate tech

#69

Post by AtlasLion »

threeseed wrote: post #45
privateSFacct wrote: post #37

Earlier quoted context omitted.

It only has to do it cheaply now because there is NO COST to putting CO2 into the air. Why are people surprised that if something is free (pumping CO2 into air) demand for it is high? You are telling me that doing a charge of let's say $10 - $100/ton of CO2 wouldn't have a DRAMATIC impact on emissions? Is $10 - $100/ton too little for a supposed climate emergency? There is so much funding and lawmaking and finger poi…

You mean a Carbon Tax ? The tax that applies to every single business, every single product, every single process, everything. The one that causes every single vested interest to come out of the woodwork and join together to make it politically toxic. We tried this in Australia. It has killed every government that even dared to discuss it. And politically it is utterly impossible to defend e.g. "Carbon tax that raise…

Not all polluters are equal, some make huge gains while doing it.

Re: We need to take CO2 out of the sky – an overview of climate tech

#70

Post by chopin »

quixoticelixer- wrote: post #46
threeseed wrote: post #45

Earlier quoted context omitted.

You mean a Carbon Tax ? The tax that applies to every single business, every single product, every single process, everything. The one that causes every single vested interest to come out of the woodwork and join together to make it politically toxic. We tried this in Australia. It has killed every government that even dared to discuss it. And politically it is utterly impossible to defend e.g. "Carbon tax that raise…

Except many countries have carbon tax

Which ones would that be? I know of many which have a tax on various forms of energy consumption. And even then, industrial consumers are exempt or have a reduced rate.
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