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Direct air capture: our technology to capture CO₂

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Re: Direct air capture: our technology to capture CO₂

#111

Post by Retric »

adrianN wrote: post #108
Retric wrote: post #98

Earlier quoted context omitted.

The earth naturally sequesters carbon on its own, we are simply vastly outpacing that process. So no we don’t need artificial carbon sequestration to hit even preindustrial levels again. Carbon sequestration is unfortunately more of a scam than a practical process. Without actual discouraging the burning of fossil fuels people aren’t going to simply stop on their own and if we can’t even get that far nobody is willin…

Natural sequestration is a very slow process. If we want to avoid tipping points we shouldn’t rely on it alone.

Slow is debatable, it’s something like 3 orders of magnitude faster than all the current artificial carbon sequestration systems in operation right now combined.

Re: Direct air capture: our technology to capture CO₂

#112

Post by the_third_wave »

culopatin wrote: post #96
the_third_wave wrote: post #90

If you insist on capturing CO₂ then capture it somewhere it is available in abundance instead of ~400 parts per million : at the source. Capture it at gas turbine exhausts, at coal-burning power station smoke stacks, maybe on board ships if the power is available to do so. Use some other process for capturing atmospheric CO₂, e.g. lime stone capture. Trying to actively capture airborne CO₂ is like creating needle-in-…

Would it be simpler to attempt to capture and compress the total of the exhaust of turbines, co2 or not, than to attempt to separate the co2?

No, that would just postpone whatever problem existed in the first place since you'd be left with a huge mass of compressed exhaust gases which do not have any use. Since those exhaust gases consist mostly of nitrogen (due to it forming ~80% of the atmosphere) this would also entail a massive waste of energy expended in compressing that nitrogen.

Separating out the CO₂ would make it possible to either use it in some form where it replaces CO₂ otherwise produced by other means - e.g. for welding, cooling, carbonation of liquids etc. - or to sequester it in some way.

Re: Direct air capture: our technology to capture CO₂

#113

Post by pydry »

johndunne wrote: post #81
onos wrote: post #73

Earlier quoted context omitted.

And one tree does 25kg per year. So each person should plant 14 * 365 / 25= 204 trees. Seems very reasonable.

Consider UK; 204 trees * 65 million people = 13.2 billion trees. Woodland estimates there's approx 3 billion trees in the UK now. That's over 4 fold increase in trees every year. I doubt the terrain/nature could support such a significant increase in just one year, let alone a number of years. But I like the idea of more trees. https://woodlands.co.uk/blog/woodland-economics/how-many-tre...

UK population density is 715 / sq mi. World average excluding Antarctica is 154.

There are less densely populated places where more trees could be planted.

Re: Direct air capture: our technology to capture CO₂

#114

Post by doikor »

kmeisthax wrote: post #6

Lots of information about land usage, not so much about power usage beyond "it'll run on renewables". I imagine their cost benefit analysis boils down to "governments will pay for it to not die", which sounds rather optimistic.

I think a part of it is waiting for the point of time when overproduction from renewables is to the point that we regularly hit 0 (or negative) prices for some parts of the day. Then you basically only run it during those times when electricity is almost free.

This is already happening on windy days in the summer in northern Europe (Finland and northern parts of Sweden/Norway).

Re: Direct air capture: our technology to capture CO₂

#115

Post by johndunne »

onos wrote: post #92
johndunne wrote: post #81

Earlier quoted context omitted.

Consider UK; 204 trees * 65 million people = 13.2 billion trees. Woodland estimates there's approx 3 billion trees in the UK now. That's over 4 fold increase in trees every year. I doubt the terrain/nature could support such a significant increase in just one year, let alone a number of years. But I like the idea of more trees. https://woodlands.co.uk/blog/woodland-economics/how-many-tre...

You don’t need a new tree each year cause they can live decades. UK 4xing it’s tree coverage sounds doable and nice!

:facepalm: you’re right! Just 4xing alone is enough to cover the population’s emission. I’m totally up for upping the tree population in the UK.

Re: Direct air capture: our technology to capture CO₂

#116

Post by specialist »

Retric wrote: post #98
specialist wrote: post #88

Earlier quoted context omitted.

Time machine is neat metaphor. Thanks for sharing. -- Net Zero is not enough. We must do Net Negative, a much bigger project than Net Zero. The goal is CO2 350ppm, or lower. Today is 417ppm. It will be >600ppm in 2050, our current global Net Zero deadline. There is no either-or. We need all the solutions. To stop and then reverse emissions: solar, wind, geothermal, nukes (old and much more new), storage, transmission…

The earth naturally sequesters carbon on its own, we are simply vastly outpacing that process. So no we don’t need artificial carbon sequestration to hit even preindustrial levels again. Carbon sequestration is unfortunately more of a scam than a practical process. Without actual discouraging the burning of fossil fuels people aren’t going to simply stop on their own and if we can’t even get that far nobody is willin…

> more of a scam than a practical process

Elites and grifters always co-opt and subvert any and all reform, revolution, rebellion. That hardly absolves us of our collective moral obligation. We must protect and provide for (present and) future humans. Despite the obstacles.

> people aren’t going to simply stop on their own

On the other hand, CDR determines the floor price of removing that pollution. Less arm-wavy than current proposals for determining carbon taxes amounts.

Anywho, I'd rather try than not try. YMMV.

Re: Direct air capture: our technology to capture CO₂

#117

Post by specialist »

slashdev wrote: post #93
specialist wrote: post #88

Earlier quoted context omitted.

Time machine is neat metaphor. Thanks for sharing. -- Net Zero is not enough. We must do Net Negative, a much bigger project than Net Zero. The goal is CO2 350ppm, or lower. Today is 417ppm. It will be >600ppm in 2050, our current global Net Zero deadline. There is no either-or. We need all the solutions. To stop and then reverse emissions: solar, wind, geothermal, nukes (old and much more new), storage, transmission…

I think we have to get used to the idea that we’re not going to be less than 600 ppm, even with CO2 capture. I would be surprised if we manage to scale that enough to make a larger difference. But that’s still much better than we’d get at without attempting to remove CO2, so it’s an important goal. The one thing that might change that is very ambitious geo engineering. Which actually is the solution that makes most s…

Yup. We'll need additional cooling strategies.

Dr Tao's MEER project is so audacious and crazy, it just might work.

https://www.meer.org

"Volts podcast: Dr. Ye Tao on a grand scheme to cool the Earth" [2022/06/08] https://www.volts.wtf/p/volts-podcast-dr-ye-tao-on-a-grand

"MEER | Mirrors For earth’s Energy Rebalancing with Dr Ye Tao at Harvard University" https://www.youtube.com/watch?v=KZAIIe4X2MU

TLDR: We need to shade a lot of agriculture. So make those shades mirrors too. Practical and scalable with today's tech and supply chain. Adding mirror shades to 15% of arable land cools enough to stay under 1.5C warming.

> ...very people who are most concerned about climate change don’t seem to support [geoengineering].

Ya. Boomers. Whaddya gonna do? Fortunately, or hopefully, the cohort of anti-development environmentalists are finally being displaced.

Meanwhile, at least someone is finally doing the prerequisite basic science on the problem:

"How to think about solar radiation management" [2023/02/24] https://www.volts.wtf/p/how-to-think-about-solar-radiation

--

Please share any other climate crisis mitigation ideas you may stumble upon. My inner geek appreciates these kinds of hacks.

Re: Direct air capture: our technology to capture CO₂

#118

Post by strohwueste »

adammarples wrote: post #101
mchannon wrote: post #55

Earlier quoted context omitted.

1000 kWh/ton (found it on google): 166 kW/ton in a sunny place: 1000 square meters/ton in a sunny place: 4 million square meters = ~1000 acres of PV to power. One unit. Yeah, that’s going to happen. /s “We’re too ashamed of our energy requirements to post them on our page and are well aware they’re dooming this technology until cold fusion comes out” is what I read between the lines on their fluff page.

Their plant is in Iceland and runs on geothermal

Geothermal is not good for global warming bc it is an additional source of energy which would normally be contained. The sun gives such amount of wattage and the earth can give so much wattage back to the universe. Nuclear, geothermal and fusion is stored energy like fossil fuel which adds to the heat in the atmosphere. Today that only amounts to 5% of global warming but if it's the only source of energy it could add more. CO2 is the focus right now bc it is continuous warming potential but the other energy forms have it too. Wind and solar is just "saving" sun energy from being instantly converted into heat and can be so used for our pleasure as it doesn't add to the input/output equation.

Re: Direct air capture: our technology to capture CO₂

#119

Post by briantakita »

photochemsyn wrote: post #103
shafyy wrote: post #59

Climate scientist David Ho has a good thread on CDR: https://mastodon.world/@davidho/109511745525784891 It's hard for people to visualize removing tons or billions of tons of #carbon #dioxide (CO₂). I propose we talked about CO₂ #removal (CDR) like a #time #machine (e.g., this machine will take us back 5 minutes). For example: Q: How far back in time does planting 100 million #trees take us? A: If one mature tree tak…

Even a complete cessation of fossil fuel use won't change the current trajectory much, it'll just mean the slope (rate of warming) doesn't get much steeper. This is due to the long lag (much of it related to slow ocean equilibration to atmospheric forcing), as well as the permafrost emissions: > "Given current rates of warming, an estimated 130-160 billion tons of permafrost carbon, could be released in the form of g…

> Humans will have to adapt to a new climate regime, by necessity. It's not going to be very pretty.

Somehow, I get a sense that the governing bodies are going to cause far more harm to people than the climate change. Similar to how Mao ordered the mass killing of Sparrows in a misguided belief that since sparrows eat crops, killing sparrows will increase yields. Unfortunately, killing the sparrows meant a predator of bugs (which eat crops in a more destructive manner) was drastically reduced. The crop yields plummeted largely from the policy to kill sparrows, resulting in millions people dying of starvation.

Human institutions with their "brilliant" ideas of intervening with nature often make matters worse, especially when chasing a single metric & ignoring other aspects of a system.

Re: Direct air capture: our technology to capture CO₂

#120

Post by GreedClarifies »

shafyy wrote: post #59

Climate scientist David Ho has a good thread on CDR: https://mastodon.world/@davidho/109511745525784891 It's hard for people to visualize removing tons or billions of tons of #carbon #dioxide (CO₂). I propose we talked about CO₂ #removal (CDR) like a #time #machine (e.g., this machine will take us back 5 minutes). For example: Q: How far back in time does planting 100 million #trees take us? A: If one mature tree tak…

We created this problem by using energy and energy is the way back out of the problem.

Energy released by burning one barrel of oil: ~6 GJ. Total number of barrels consumed per year: ~100M

Total energy per year: 6 * 10^17 J

Solar flux on 10^17 J/s or 3 * 10^24

if we had a machine that could convert CO2 -> Carbon in some stable form, we would need to use 10^-7 of the earth's solar flux.

At a very high level such a machine would have two principle "knobs" (1) the efficiency and (2) percent of earth that would need to be covered. The product of the 2 must equal (or be less than) 10^7.

Some example parameters:

Efficiency : 10^-2 Area: 10^-5

This seems wildly plausible for some microbe that we design in the near future that lives in the ocean. This efficiency parameter is lower than current plants.

For those wild eyed technologists that think we can beat nature by a good amount:

Efficiency : 10^-1 Area: 10^-6

That's a couple of hundred square miles. That seems paltry for an "existential threat". Even a couple of orders of magnitude more area seem like they would be fine to sequester for this purpose.

This type of technology seems well within our grasp (or within the next 20 years). I never understand the hysteria over this topic.

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