3 ms·

DAC is nowhere near the scale needed to make even a tiny dent in our carbon emissions, and it's easy to be cynical looking at this (this plant can capture about

DAC is nowhere near the scale needed to make even a tiny dent in our carbon emissions, and it's easy to be cynical looking at this (this plant can capture about 2000 American's carbon emissions). One thing I do like about this is that we get an actual, concrete, and correct "cost of carbon" from it. Sure, there are caveats (i.e. you can't just build 5MM of these in Iceland), but having a real number that doesn't include hand-waving around whether the Brazilian farmer would have cut down those trees or not is a good thing for offsets, future planning, markets, etc.

tito 4y ago
"Cost of carbon" -- yes, one scenario is that society dumps a few billion dollars into carbon removal technologies only to learn "oh shit this stuff is realllllllly expensive to pull out later...let's decarbonize overnight". Pretty sure all of us air miners would take that as a win. edit: I've also seen a similar argument made for developing geoengineering solutions. Being willing to dump chemicals into the upper atmosphere to reflect sunlight makes a lot of people think "oh shit they're really serious about this climate change stuff arent' they", and then the outcome of "we should take this more seriously".
brundolf 4y ago
Does it also serve as a test-bed for improving the technology? Like with fusion reactors that will never themselves be energy-positive
- kec 4y ago
  CO2 makes up roughly 0.04% of the atmosphere. Handwaving, that means for every ton of carbon you remove you'd need to process at least 250 tons of air. To capture humanities current yearly output, you'd need to process over 7 Trillion tons of air per year... the scales just don't make sense.
  - tito 4y ago
    Yes the scales are hard to fathom. And we've been doing that for about 100 years. It's not pretty, but there's a trillion tons of excess carbon dioxide in the atmosphere. We need to stop emitting as fast as possible and remove the rest. Every gallon of gasoline burned adds 20 pounds of carbon dioxide to the atmosphere.
  - dane-pgp 4y ago
    > 7 Trillion tons of air per year Thanks for running these numbers. I have a few more calculations to add which support what you're saying. Let's consider a fairly standard industrial air compressor[0] which has a rating of "CFM at 90 PSI: 18.1". This means 18.1 cubic feet of air per minute. A cubic foot of air "weighs approximately 0.0807 lbs" according to an expert answer on PhysLink[1]. Using `units`, then: You have: 18.1 * 0.0807 lbs / minute You want: tonnes / year * 348.46671 So 7 trillion tonnes would require about 20 billion times more air movement than one of these compressors. [0] https://ingersollrandcompressedair.com/ss5l5-single-stage-air-compressor.html https://ingersollrandcompressedair.com/ss5l5-single-stage-ai... [1] https://www.physlink.com/education/askexperts/ae650.cfm https://www.physlink.com/education/askexperts/ae650.cfm
    - chmod775 4y ago
      Can you explain how the comparison to air compressors is at all relevant here? Those move a tiny amount of air. Your typical tiny PC fan can move 70 CFM, so about 3.5 times the amount of your industrial air compressor. A typical 30 inch fan can easily move 10000 CFM. Here's what I could find on how the technology works: > While a few different techniques have been developed, the most common involves industrial-scale fans that transmit ambient air through a filter. This latter component then uses a chemical adsorbent (which holds molecules in the form of a thin film on its surface) to produce a pure, storable stream of carbon dioxide. https://singularityhub.com/2019/08/23/the-promise-of-direct-air-capture-making-stuff-out-of-thin-air/ https://singularityhub.com/2019/08/23/the-promise-of-direct-...
      - dane-pgp 4y ago
        I wasn't sure that an air compressor is a good comparison, but I thought that a typical fan was also not a good comparison because the air it moves doesn't have much resistance to it. Presumably if you're trying to force air through a process that separates out CO2, there will be more back pressure than just blowing into the open air. Assuming, though, that the process could keep up with the air flow that 100 of those 30 inch fans could produce (if we imagine a shipping container being about 10 feet wide by 10 feet tall) then that's 1 million CFM, which is 50,000 times my original comparison, so only 400,000 units would be needed. To pick some more arbitrary numbers, if 100 factories were built, each producing one unit per week, that would take 4000 weeks or roughly 80 years. Feel free to consider more realistic numbers, which may lead to different conclusions.
sauwan 4y ago
> DAC is nowhere near the scale needed to make even a tiny dent in our carbon emission One could have said the same thing for PV panels 20 years ago.

tito 4y ago

"Cost of carbon" -- yes, one scenario is that society dumps a few billion dollars into carbon removal technologies only to learn "oh shit this stuff is realllllllly expensive to pull out later...let's decarbonize overnight". Pretty sure all of us air miners would take that as a win. edit: I've also seen a similar argument made for developing geoengineering solutions. Being willing to dump chemicals into the upper atmosphere to reflect sunlight makes a lot of people think "oh shit they're really serious about this climate change stuff arent' they", and then the outcome of "we should take this more seriously".

brundolf 4y ago

Does it also serve as a test-bed for improving the technology? Like with fusion reactors that will never themselves be energy-positive

kec 4y ago
CO2 makes up roughly 0.04% of the atmosphere. Handwaving, that means for every ton of carbon you remove you'd need to process at least 250 tons of air. To capture humanities current yearly output, you'd need to process over 7 Trillion tons of air per year... the scales just don't make sense.
- tito 4y ago
  Yes the scales are hard to fathom. And we've been doing that for about 100 years. It's not pretty, but there's a trillion tons of excess carbon dioxide in the atmosphere. We need to stop emitting as fast as possible and remove the rest. Every gallon of gasoline burned adds 20 pounds of carbon dioxide to the atmosphere.
- dane-pgp 4y ago
  > 7 Trillion tons of air per year Thanks for running these numbers. I have a few more calculations to add which support what you're saying. Let's consider a fairly standard industrial air compressor[0] which has a rating of "CFM at 90 PSI: 18.1". This means 18.1 cubic feet of air per minute. A cubic foot of air "weighs approximately 0.0807 lbs" according to an expert answer on PhysLink[1]. Using `units`, then: You have: 18.1 * 0.0807 lbs / minute You want: tonnes / year * 348.46671 So 7 trillion tonnes would require about 20 billion times more air movement than one of these compressors. [0] https://ingersollrandcompressedair.com/ss5l5-single-stage-air-compressor.html https://ingersollrandcompressedair.com/ss5l5-single-stage-ai... [1] https://www.physlink.com/education/askexperts/ae650.cfm https://www.physlink.com/education/askexperts/ae650.cfm
  - chmod775 4y ago
    Can you explain how the comparison to air compressors is at all relevant here? Those move a tiny amount of air. Your typical tiny PC fan can move 70 CFM, so about 3.5 times the amount of your industrial air compressor. A typical 30 inch fan can easily move 10000 CFM. Here's what I could find on how the technology works: > While a few different techniques have been developed, the most common involves industrial-scale fans that transmit ambient air through a filter. This latter component then uses a chemical adsorbent (which holds molecules in the form of a thin film on its surface) to produce a pure, storable stream of carbon dioxide. https://singularityhub.com/2019/08/23/the-promise-of-direct-air-capture-making-stuff-out-of-thin-air/ https://singularityhub.com/2019/08/23/the-promise-of-direct-...
    - dane-pgp 4y ago
      I wasn't sure that an air compressor is a good comparison, but I thought that a typical fan was also not a good comparison because the air it moves doesn't have much resistance to it. Presumably if you're trying to force air through a process that separates out CO2, there will be more back pressure than just blowing into the open air. Assuming, though, that the process could keep up with the air flow that 100 of those 30 inch fans could produce (if we imagine a shipping container being about 10 feet wide by 10 feet tall) then that's 1 million CFM, which is 50,000 times my original comparison, so only 400,000 units would be needed. To pick some more arbitrary numbers, if 100 factories were built, each producing one unit per week, that would take 4000 weeks or roughly 80 years. Feel free to consider more realistic numbers, which may lead to different conclusions.

sauwan 4y ago

> DAC is nowhere near the scale needed to make even a tiny dent in our carbon emission One could have said the same thing for PV panels 20 years ago.