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Sucking carbon dioxide from air is cheaper than scientists thought

531 points by kjeetgill 8y ago

kjeetgill 8y ago
Substantial conversation on reddit: https://www.reddit.com/r/science/comments/8pbuqv/sucking_carbon_dioxide_from_air_is_cheaper_than/ https://www.reddit.com/r/science/comments/8pbuqv/sucking_car...
- tptacek 8y ago
  The r/science conversation crushes the HN conversation and is worth skimming.
sremani 8y ago
This is good news, esp. given the context from this spectrum article why we need some technologies like these.. https://spectrum.ieee.org/energy/renewables/what-it-would-really-take-to-reverse-climate-change https://spectrum.ieee.org/energy/renewables/what-it-would-re...
advisedwang 8y ago
Apparently burning petrol releases about 2.31 kg of CO2 per liter. At 100 USD per tonne of CO2 it would cost 0.23 USD per liter of petrol if we captured every bit of CO2 released. That's within the realm of possibility.
- jessaustin 8y ago
  Yeah it seems pretty straightforward to just start taxing at that rate and be done with all the nonsense.
  - njarboe 8y ago
    Except for the part that this process takes electricity to do. If the process can be turned off and on quickly, it would be a great use for excess wind and solar power.
    - ishjoh 8y ago
      One nice thing about this is that you could pull carbon out of the atmosphere from remote locations, in particular hydro electricity could provide abundant, inexpensive, and clean power.
      - njarboe 8y ago
        Just what I was thinking. Like west Texas with wind where electricity prices go negative quite often in the middle of the night.
        DoctorOetker 8y ago
        guys, capturing CO2 or not releasing it at a power plant are the easy and cheap part. It's what you do with the voluminous CO2 gas. Converting to fuel will be very expensive (although if the conversion process can be throttled quickly, which I highly doubt, we could use peak solar and wind, and treat fuel as a battery). The figures you calculate is meaningless, factories could always have been fitted with carbon capture for a relatively low energy cost. The reason this is not done at scale is there is zero demand for CO2! (unless you pay someone carbon credits to pretend to need CO2!!!)
        linkregister 8y ago
        Yes, at that scale, the price of CO2 approaches zero, especially with the caveat that it shouldn't be reintroduced (as with carbonated beverages and pressurized machinery). Carbon dioxide sequestration or transformation is the next step. Getting the first step to be economical is also nice.
        njarboe 8y ago
        CO2 injection is already done in many oil fields for enhanced oil recovery. People already know how to pump it down into the earth and track where it goes. Put a decent price on removing CO2 from the atmosphere and people will quickly figure out how to do it for a nice profit. Lots of old oil wells in west Texas also.
  - 8xde0wcNwpslOw 8y ago
    A funny coincidence: the excise duty on petrol here consists of several "parts", one of which is the carbon dioxide tax, which is currently about 0.25 USD/litre (in total the fixed taxes amount to a bit over 1 USD/litre).
    - pbhjpbhj 8y ago
      I assume "here" is USA, but you could be converting to dollars from local currency?
      - 8xde0wcNwpslOw 8y ago
        I'm converting because earlier messages used dollars as well. I doubt that taxes that high exist anywhere in the US (1 USD/litre being almost 4 USD/gallon after all).
- lifeisstillgood 8y ago
  Well that's a Holy Fuck moment for me. I thought the parent here had made a off-by-orders of magnitude error - how can a liter of petrol (which itself is only a kg) produce 2.31kg of CO2 ... i mean work it out, all the carbon would have to attach to 2x oxygen ... ok that might just ... err ... see this reference for a walk through of the calculation - http://ecoscore.be/en/info/ecoscore/co2 http://ecoscore.be/en/info/ecoscore/co2 Every time I pour petrol into my tank I am basically pouring twice that weight of CO2 into the atmosphere. I may be very dumb but I never thought if it like that before. I always assumed CO2 was a minor byproduct ... but like breathing. oh dear.
  - ChrisLomont 8y ago
    Consider it this way. That entire liter turns to gas when burned, and in doing so it combines with O2 and other things in the air, resulting in the total weight of the liter + what it combined with entering the air.
  - voidmain 8y ago
    > like breathing When you eat 1kg of peanut butter, if I've done my math right, you'll breathe out about 2.3kg of CO2. Dry cereal would be about 1.5kg. Most foods have a lot of water in them, though.
    - lifeisstillgood 8y ago
      Darn and that looked like a pretty decent breakfast :-)
    - dTal 8y ago
      I would think you're unlikely to produce sufficient bile to metabolise an entire kilogram of peanut butter at once. Most likely you'd get really nasty, oily runs at best, and quite possibly throw up.
  - njarboe 8y ago
    Yes, but the weight of the oxygen is in the atmosphere already. And for a bonus, all the hydrogen you burn removes O2 from the atmosphere in the form of water, reducing the weight of the atmosphere (and therefor the greenhouse effect of the atmosphere). How much the reduction of O2 from H burning offsets the transformation of O2 to CO2 is left as a problem for the reader. If anyone knows of a paper that discusses this effect, I'd love to read it.
- ebbv 8y ago
  You are making the big assumption this article is accurate and scalable. I’m not so sure. You’re also assuming that capturing everything scales linearly from capturing something.
  - sunstone 8y ago
    Bill Gates has been funding this project since its inception and one of the founders is a world expert in global warming and a Professor at Harvard so you'll have to do better than unsubstantiated innuendo here. Roll out some real facts rather just than pulled out of your ear guesses.
    - ebbv 8y ago
      You realize the argument you’re making (“Smart people are backing this!”) is exactly how Theranos and many other scams go on as long as they do right? All I did was bring up some concerns. I did not state any facts, merely point out details that need to be addressed. Chill out.
      - sunstone 8y ago
        This may give you some reassurance.[1] [1]https://arstechnica.com/science/2018/06/machines-that-suck-co%E2%82%82-from-the-air-might-be-cheaper-than-we-thought/ https://arstechnica.com/science/2018/06/machines-that-suck-c...
        ebbv 8y ago
        Why would it? It’s just another one sided fluff piece. Basically a press release for the product much like the original article.
- sunstone 8y ago
  Yes, I would happily pay that for "carbon neutral" gas.
  - JetSpiegel 8y ago
    Considering the US has literally entered wars that cost trillions over oil disputes, I think you are pretty much alone.
    - ISL 8y ago
      Counter-example: I'd happily pay at least that much for carbon-neutral or carbon-reducing fuel. Source: Am registered-voter citizen of the United States.
      - JetSpiegel 8y ago
        I'm not disputing that, just the the political climate makes that opinion a miniscule minority.
    - JanisL 8y ago
      Sounds like others are paying a fairly high price in that case but just more indirectly
- NovaS1X 8y ago
  This is a mind blowing concept. I mean, it makes sense when I read: http://ecoscore.be/en/info/ecoscore/co2 http://ecoscore.be/en/info/ecoscore/co2 But does this take into account catalytic converters or other emissions controls? Cats take the CO from the combustion process and turn it into CO2, the gas you're referencing. I'd just like to clarify because this is a big revelation in my way of thinking about pollution. Are we really releasing that much CO2 post emissions controls?
  - jaggederest 8y ago
    Emissions controls have no effect at all on CO2 emissions. They don't alter the fundamental stoichiometry of a pure octane combustion: 2C8H18 + 2502 -> 16CO2 + 18H2O So yes, burning a liter of octane (6 moles) will use ~1600 liters of oxygen and emit ~1000 liters of carbon dioxide, or a little over two kilograms. In pure carbon terms, it produces (drumroll) the exact same amount as the input: 49 moles at 12 g/mol or 590 grams.
pier25 8y ago
Doing a little math... Considering 1100 Gtons in the atmosphere and $200 per ton would be roughly $220 trillions. The current world's GDP is $78 trillions. Even if the world invested $10 trillions every year it would still take 20 years to remove all the carbon emitted between 1850 and today. Of course we would keep pumping about 37 Gtons per year (and growing). https://www.carbonbrief.org/analysis-global-co2-emissions-set-to-rise-2-percent-in-2017-following-three-year-plateau https://www.carbonbrief.org/analysis-global-co2-emissions-se...
- jessaustin 8y ago
  Maybe the first goal could just be removing the current year's production? That would still be a vast improvement over every other proposed solution.
  - Scarblac 8y ago
    By his numbers that's still ~ $7.4 trillion, or about 10% of the world's GDP. And it doesn't include storing the captured CO2 anywhere permanent. I think it's a lot more practical to reduce our emissions to close to zero, hard as that is.
    - jessaustin 8y ago
      Anything we do is going to be expensive. "Stopping all use of fossil fuels" like you suggest would also be very expensive, even if we ignore obvious costs like disposing of all the corpses created by such an endeavor.
- epistasis 8y ago
  20 years is an incredibly quick timespan in which to do this. If we can become carbon neutral by 2040 and carbon negative after, we can stave off many of the worst parts of climate change.
  - padobson 8y ago
    I'm with you. I have to believe a joint country climate accord where member nations pledge to suck X gigatonnes of carbon from the atmosphere (or finance those that do) is a much easier political sell than 1) taxing fossil fuel companies/cartels or 2) enforcing emissions restrictions on various industries. Cleaning up 150 years of emissions in 20 or 40 or even 60 years seems like a miracle on par with the moon landing or eradicating smallpox.
User23 8y ago
I worry that well-meaning efforts at mass climate engineering will cause far more harm than letting nature run her course. I'm not convinced there is a causal relationship between human activity and CO2 levels or average temperatures (ignoring urban heat island and similar effects). Sure there is a correlation, but we all know what that means. The kind of atmospheric engineering that scares me is exactly the tool that would be required to show a causal relationship. Another point of concern is that none of the doom and gloom predictions are made by any climate model. All a climate model can do is make predictions about, well, climate. It takes an economic or some other sociological model to predict how that change in climate will affect human beings and societies, and what the costs (and benefits!) will be. Even if you trust the climate models 100% you'd be a fool to trust the economic or sociological models. How can one rationally justify an intervention is worth the cost when one can't know the cost of what is being prevented?
- deleted 8y ago
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- epistasis 8y ago
  You have a lot of strange beliefs. Can you back any of them to the degree that you demand of others? Have you considered taking a skeptical approach, and looking at the arguments that you disagree with a prior? I suspect that once you do, you will be more than convinced about, e.g. humans having increased CO2 levels. If you are not convinced of even that basic fact after looking at the evidence, I would suggest that there is not evidence at all that could change your mind. I.e. this is a religious or political conviction rather than an evidence based belief. The idea that CO2 level rises is not due to human activity is as far out there as saying you've invented a perpetual motion machine. Honestly.
  - User23 8y ago
    I believe I am taking the skeptical approach. I've read a lot on the subject and most of what I find is appeals to fear and other emotions, for example that climate change is going to destroy the earth. Actually the Earth did quite well during the carboniferous period all things considered. Maybe human activity is responsible for the increase in CO2. I don't deny that. They are correlated. I accept that. But maybe there is a third variable or combination of variables that is driving CO2 levels? Is that really so unreasonable. It seems awfully anthropocentric and, honestly, arrogant, to assume that human activity is the only thing that affects atmospheric composition. Perhaps you should take your own advice? > The idea that CO2 level rises is not due to human activity is as far out there as saying you've invented a perpetual motion machine. Honestly. No it isn't. Also, I never positively stated that it isn't.
maxander 8y ago
Remember that, a priori, you should be far more skeptical of studies with this sort of result than, say, studies showing that neocortinoids don't harm bees or that the latest blockbuster pharmaceutical has no side effects. The sheer mass of money in position to lobby for the "fossil fuel use is fine!" position dwarfs that of all other financially-fraught research questions put together. To wit; the company behind the paper in question, Carbon Engineering, is noted by Wikipedia as having "oil sands financier N. Murray Edwards" as one of it's principal backers. And the article's "outside expert's opinion" quote comes from Stephen Pacal, co-director of the Carbon Mitigation Initiative at Princeton- which has an "extended partnership with BP" worth a great deal of money [1]. The financial conflicts behind this research are staggering. [1] https://www.princeton.edu/news/2010/11/18/carbon-mitigation-initiative-receives-11-million-through-extended-partnership-bp https://www.princeton.edu/news/2010/11/18/carbon-mitigation-...
- zzzeek 8y ago
  this is kind of interesting as there's some reverse/upside down ideas that come out of it: 1. the big oil companies and the massive political machine that supports them drops the whole "global warming isn't real" line, no more snowballs being taken in to congress and all that. Because now they can just say they'll suck it out of the air and they can continue to think they can keep burning all the coal and oil they want (which of course they should not). Once everyone is on the same page that global warming is real, they can't go back on that. If the approach here proves to be insufficient (which it probably is), a lot of political points have been scored in any case. 2. the machinery to suck out the CO2 is another big "green" industry, like solar or wind, but doesn't compete with oil/coal! it's meant to mitigate the damage they do. So as you've noted, way more money and attention might end up going here, increasing the chance of its viability. 3. No matter what happens with the rate of burning oil/coal, we need this anyway. There's consensus that we're pretty much over the point of no return with warming due to all the ice that has melted, and if the permafrost goes that might be catastrophic.
  - briandear 8y ago
    Is anyone actually debating if climate change is happening? The debate is on the degree of human influence.
deleted 8y ago
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Tloewald 8y ago
Let's take this article at its word, which is that right now we can bury carbon for $600/tonne (forget the speculative $100/tonne) which equates to $1.32/liter of gas (based on the speculative $0.22/liter). In California right now gas costs ~$4/gallon (which is high compared to most of the US but low compared to most of the developed world), so it's not an insane amount to pay for carbon-neutral gas. The interesting thing to me is that this is presumably something ideal to do with excess solar power (e.g. it's a much better deal than paying other states to use it, which is what California is currently doing). Another question is how does this compare, price-wise, to using solar power to create fuel (e.g. hydrogen) and truck it around the way we do with gas.
DrTung 8y ago
In a few years I'll probably have grandkids and when I read this, think it increases the chance that those kids will still be able to go to Disney World in Florida, i.e. it will not be submerged.
- jonknee 8y ago
  FWIW either way they will be able to visit, Orlando is not on the coast and is ~100' above sea level.
- kirubakaran 8y ago
  Don't worry, they'll move Disney World to dry land.
- mikec3010 8y ago
  By that time Disney world will just be a VR app you load on your 8k VirtualStation via fiber optic link with others. Disney will long have replaced all their parks with simulation because focus groups found that while consumers preferred the real park, the amount of lost park sales was less than the gains of zero liability, shutting down the park and firing those employees who were eating into shareholder profits. The park now only exists as a museum and luxury apartment homes, with paid autonomous bus tours.
blacksqr 8y ago
They say they can make synthetic fuel at $1/liter with CO2 input at $100/ton. There's plenty of CO2 available commercially at about $20/ton. If they can make synthetic fuel economically out of CO2, they should be doing that RIGHT NOW, not waiting until they've perfected the air extraction process. They could use the money they made from the fuel to speed up R&D on the extraction process.
Robotbeat 8y ago
Good. Then we should immediately require fossil fuel companies to do this or pay for someone else to do it as well as long-term storage and insurance for the storage.
theptip 8y ago
> The result, after further processing, is a calcium carbonate pellet that can be heated to release the CO2. That CO2 could then be pressurized, put into a pipeline and disposed of underground. I'm curious why you wouldn't just bury the calcium carbonate pellets at this point (or sell them, since they have value). Pumping CO2 underground isn't a cheap or reliable process yet as far as I can tell. > the company is planning instead to use the gas to make synthetic, low-carbon fuels. I suppose the answer is that the synthetic natural gas is more valuable than the calcium carbonate. Seems like adding more steps than strictly necessary though. Edit: > In the United States, Carbon Engineering is eyeing a recently expanded subsidy for carbon capture and sequestration, which could provide a tax credit of $35 per tonne for atmospheric CO2 that is converted into fuels. Missed this bit in the article. Regulatory arbitrage, which is a very good reason to add another step in your process, even if it's not strictly optimal.
- codefined 8y ago
  I haven't done chemistry in years, but I think you can fairly easily reuse the calcium carbonate pellet once it has been heated. I imagine the cost of energy is significantly less than the cost of the raw resources.
- scythe 8y ago
  >I'm curious why you wouldn't just bury the calcium carbonate pellets at this point Potassium hydroxide absorbs carbon dioxide: 2 KOH + CO2 >> K2CO3 + H2O Calcium oxide regenerates potassium hydroxide: CaO + K2CO3 + H2O >> CaCO3 + 2 KOH Calcium oxide is recovered by heating: CaCO3 + heat >> CaO + CO2
- mikec3010 8y ago
  Why go that far? Why not grow acres of a hardy fast growing plant like hemp or seaweed, fertilized with sewage water. Harvest and dry the plant, bale it, and stack the bales underground? Or the Midwest farmers could bale their corn waste bury it instead of burning it. Arizona could pipe in seawater and grow seaweed by the ton.
exabrial 8y ago
I'm curious how this competes with a bunch of algae in a lake
ajnin 8y ago
Based purely on numbers CO2 capture seems like a plausible idea. The article cites a cost of $0.22 cents per liter of fuel to capture an equivalent amount of CO2. Based on the current 93 million bbl or roughly 15 billion liters of oil consumed every day worldwide, the cost would be around 1.2 Trillion USD per year, or 1.5% of the global GDP. A lot but within the real of feasibility. However to achieve that in practice we would need to build enough CO2 capture plants to capture the CO2 released by all human activity, and we've been building machines that release CO2 for decades. The effort to catch up is immense. The similar company Climeworks, cited in the article, has an example of such a plant here : http://www.climeworks.com/our-products/ http://www.climeworks.com/our-products/. The DAC-18 variant, which looks like the prototype that they actually built, it is a complex 3 stories high structure with 90m^2 of ground area, and according to the product page it can capture 2460 kg per day, although that is probably under ideal conditions and in practice it could be considerably less. According to a quick search we released around 36.75 Gt of CO2 last year. To capture that, we would need to build 36.75e12/365/2460 = 41 million such plants, at the bare minimum. And that would be only break even, we'd need even more to start capturing the excess CO2 already in the atmosphere. That seems unrealistic.
- sjg007 8y ago
  Well, we could plant more trees, not deforest the Amazon.. Maybe grow some algae or something too.
WalterBright 8y ago
Probably the most cost-effective way of sucking CO2 out of the air is planting trees on a huge scale.
- cbHXBY1D 8y ago
  A user on reddit did some napkin math on the r/science submission of this article. The tl;dr is we don't have enough land area for the amount of trees needed to sequester 1,100 gt of carbon. https://www.reddit.com/r/science/comments/8pbuqv/sucking_carbon_dioxide_from_air_is_cheaper_than/e0aendn/ https://www.reddit.com/r/science/comments/8pbuqv/sucking_car...
  - BurningFrog 8y ago
    If you read it closely, it says we can't do it in one year, which seems overambitious...
  - WalterBright 8y ago
    Trees can't do it all, but they can help a lot and are cheap and we like trees!
- krzat 8y ago
  We should GMO a plant that spreads in the dessert and produces energy heavy fruit (probably nuts) that can be buried. Or maybe a tree that grows super deep and thick roots.
hmwhy 8y ago
Economics and policies aside, I’m a bit skeptical about the approach described in that article regarding the use of potassium hydroxide (production, transportation) and it’s subsequent processing (to re-release the captured carbon dioxide, somehow transform it into fuel, and let people release again!?); even just the logistics would most likely be releasing a good amount of CO2 if cost is such a huge factor in this. It just feels like the carbon dioxide released would be a substantial offset to that captured. Ultimately, it would still be viable if the net outcome is a reduction in atmospheric carbon dioxide; but I’m not convinced, at least with the approach in question, that humanity’s interest is at the top of the list. It would be absolutely fantastic and very much appreciated if someone who knows about the actual “accounting” of carbon dioxide in this type of carbon sequestration technology can comment.
fallingfrog 8y ago
The thermodynamics of this seems wrong to me. You would have to burn at least a ton of oil to draw a ton of carbon from the air, probably more like 2 tons due to inefficiencies. The cost of oil is 418 dollars a ton. So to make this even remotely plausible you have to assume access to an energy source which is 4 times cheaper than oil on a cost basis. So cheap, in fact, that unburning carbon from the air would be twice as cheap as mining it out of the ground.
- snarf21 8y ago
  Let's say the thermodynamics are wrong. At some level, it doesn't matter by how much. I think of this like a battery. Use wind power or tides even solar to create this gas. Then you have easy to transport energy that is carbon neutral as you've added no new CO2 to the air. That is the excitement, not the cost per unit of energy.
- RockyMcNuts 8y ago
  hypothetically, if you burn 2 tons of oil and you get out of the atmosphere 1 ton of oil equivalent to burn, then if your emission-free energy cost is 1/2 the price of oil, you break even on cost, and reach carbon neutral, no? Alternatively, if your emission-free energy cost is same as oil, you tax oil-based energy 100% and now you reach carbon-neutral? I don't see why it has to be 4x cheaper, clarification would be helpful.
  - DoctorOetker 8y ago
    he's estimating the energetic i.e. objective cost. If the government subsidized to the point of us stopping pumping up oil or true fossil neutral rate (ignoring the CO2 already up there, which will over hundreds of years fall back to natural levels), then we would have to manufacture our fuels... with what energy? sure in the long term I think we can use renewable, but it isn't deployed yet. The only way this makes sense is if we deploy true renewable energy, and stop allowing fossil fuel industry to masquerade as green.
- ISL 8y ago
  The majority of the mass (72%) of CO2 is oxygen, not carbon. By convention, the "tons" generally quoted in climate literature are carbon-dioxide, not pure carbon. Using $418/ton of oil: $418 * (1-0.72) = $117, in striking range of the $100 target. Where renewables match or exceed hydrocarbon fuel, $100 would appear to be a reasonable price.
danschumann 8y ago
The problem of climate change is the same as the obesity problem, if you phrase it like this: "There is something that is going to kill you in 20 years if you don't change your habits today". Most people wait until they have a significant event (heart attack, they can't get up the stairs without being out of breath, etc) until they change. I always figured it would take some sort of big event for people to change, and then when that happened, we would start working on retroactive fixes ( like sucking co2 out of the air ), rather than preventative fixes.
jillesvangurp 8y ago
Here's a related article that circulated in finnish media a few days ago: https://yle.fi/uutiset/osasto/news/finnish_researchers_use_air_solar_power_to_create_renewable_hydrocarbon/9661164 https://yle.fi/uutiset/osasto/news/finnish_researchers_use_a... This is about the apparent work of a Finnish researcher to come up with a scalable way to produce fuel from air such that it can be done locally. Think gas stations producing their own gas. Right now this would be relatively expensive because of energy cost but as those drop and the technology is improved, that cost can go down. Stuff like this not surprising for anyone that has followed news around renewables lately and a very cool side effect of the fact that renewable energy prices have been dropping exponentially for quite some time now combined with the fact that the cost of lots interesting chemical processes are primarily driven by how much energy is required. As energy becomes cheaper, those chemical processes become more feasible and the demand for more energy causes people to invest in making that cheaper further. The same economic dynamic that is causing us to destroy our planet is also producing the solutions for saving it. For example, producing clean water is a trivial process if you have cheap energy. This is why desalination plants are popping up in lots of places where clean water is scarce and they tend to be paired with wind/solar plants. You can also produce fuels out of water and the resulting fuels, whether it is hydrogen or hydrogen peroxide, are useful ways of storing energy. Oil is a scarce resource that is hard to procure and therefore relatively expensive. If there's an energy intensive way to produce oil from CO2, that's great news because that means it's just a matter of time before the price of that energy drops enough to make that worthwhile. Things like this can go from being too expensive to only slightly more expensive to being magnitudes cheaper in the near future. What I love about this is that climate change can be countered with simple economics rather than idealism. Once we stop pumping new co2 in the atmosphere for cost reasons because we found a more cost effective way to just suck it from the atmosphere, nature will do it's thing and help us revert the effects of the past centuries. We don't actually need to actively clean up the atmosphere, our planet is fully capable of doing that by itself given enough time. Also worth pointing out that oil is used for more than just fuel. So, stuff like this is relevant even if we switch to electric vehicles. We still need to produce plastics and other materials. All of that can in principle be done with co2 harvested straight from the air as well.
Reason077 8y ago
It seems like at $94/ton CO2, we're still a long way from where this becomes viable. At that price, to offset humanity's annual 36 Gt CO2 emissions (36 billion tons) we'd need to spend about $3.2 trillion. Per year. Surely the cost of reducing CO2 emissions - the cost of upgrading emissions sources to alternative, lower-carbon technologies - is much less than $94/ton. And that's where we should be focusing our efforts and funding for the foreseeable future.
erikig 8y ago
Yep, just plant a tree or two ;)
cvaidya1986 8y ago
What if we all plant 2 trees each in our lifetime?
AtlasBarfed 8y ago
Soooo, around $100/ton. And google says we currently pump 40 billion tons per year. Let's ballpark: average 5 billion per year for 100 years. 500 billion excess tons. 50 trillion dollars to remove what we've already polluted. + 4 trillion per year to offset what we're at already. Yeah, nothing about that is "cheap". Maybe... slightly less astronomically expensive. And a lot of cheap carbon capture is "pump it into the ground", which, while I'm not a geologist, but I'm guessing the petroleum folks aren't looking to hard for leaks back into the atmosphere. But given those numbers, greening the sahara seems like a much better approach than any industrial approach.
selimnairb 8y ago
Unless we stop burning fossil carbon, pulling carbon out of the atmosphere to create fuels that we will then burn makes zero sense, in terms of mitigating climate change; even if we used solar energy to do this, there would be no net decrease in carbon in the atmosphere. This only makes sense if we use a carbonless energy source and “permanently” sequester the carbon somehow.
FrozenVoid 8y ago
Its not profitable to clean: even if cleaning was paid for by the government, most cleaning efforts would be commercial enterprises simulating maximum cleaning effort(like the incentive to collect rat tails will result in rat breeding farms, the "environment cleaning industry" will be most profitable with more pollution and costlier cleaning incentives/bonuses ). It will result in encouraging more pollution and removing all safeguards(clean coal? we'll clean it up later!) towards a new industry whose main interest would be preserving pollution forever to profit from cleaning it up. Like a pharmaceutical industry, the symptoms are more profitable than curing the disease completely.
rdiddly 8y ago
What's that old saying... usually misattributed to Einstein... you can't solve a problem using the same frame of mind that created it? We have a problem of too much CO2 caused by massive deployment of complex, energy-intensive industrial facilities and processes, and they want to fix it using a fairly complex and energy-intensive industrial facility/process (with giant air blowers and all), that itself is dependent on other complex industrial processes for its manufacture, transport, construction and operation. And perpetual energy use to run the fans... I mean? Are we sure it's a net positive CO2 capture after all that? And if so, is it still a net positive after the CO2 they've captured is turned (by means of even more energy input) into "low carbon fuels" that are then burned, releasing CO2 back into the atmosphere? I mean it's great if it works and all. I just feel like the real solution doesn't look like this.
lastUsername 8y ago
"The Paris Agreement’s inclusion of 1.5°C has catalysed fervent activity amongst many within the scientific community keen to understand what this more ambitious objective implies for mitigation. However, this activity has demonstrated little in the way of plurality of responses. Instead there remains an almost exclusive focus on how future ‘negative emissions technologies’ (NETs) may offer a beguiling and almost free “get out of jail card”. This presentation argues that such a dominant focus, evident for 2 and 1.5°C, reveals an endemic bias across much of the academic climate change community determined to voice a politically palatable framing of the mitigation landscape – almost regardless of scientific credibility." Please read: https://kevinanderson.info/blog/duality-in-climate-science/ https://kevinanderson.info/blog/duality-in-climate-science/ The problem here is cultural, not scientific. Real science about climate change is not politically palatable, NETs represent an easy way out.
- frockington 8y ago
  And if we were trying to do real science we'd have to actually find proof of cause and effect. I still have yet to find convincing proof that CO2 is the culprit. Te level of CO2 in the ar should be addressed, but I am worried that we have culturally painted CO2 as such a bad guy that the underlying cause of global warming will never be found
08-15 8y ago
So they are talking about a plant, soon to be built, that will capture about 50.000 tons of CO2 per year. Amazing! A single coal fired power plant (1GW) emits 12 million tons of CO2 per year. Seriously, this stuff won't work, and it's pointless as long as fossil fuels are burned somewhere on Earth. It's bloody obvious what to do instead: (1) stop burning coal for electricity, (2) stop burning methane ("natural" gas) for electricity, (3) stop burning methane for process heat, (4) stop using methane to make fertilizer, (5) use electrified railways instead of trucks for most transportation. Then it makes sense to talk about synthetic fuels, CO2 capture, electrifying the remaining transportation, etc, but not before.
- mhandley 8y ago
  I agree about the priorities. But to do what you suggest, to the extend that it needs to be done, we need much better ways to cope with variability of renewables. We probably need a whole range of energy storage solutions; no single one will be sufficient. And then there are aviation and shipping, neither of which is going electric any time soon. So starting work on using excess power when renewables are over-generating to capture CO2 and using it to make carbon-neutral liquid fuels seems to also be a key part of the long-term picture.
  - 08-15 8y ago
    > aviation and shipping Another distraction. They don't matter as long as coal is being burned. > renewables are over-generating Even then, trying to capture a trace gas is the dumbest thing anyone could attempt. Especially if the process involves calcining lime---what a ridiculous waste of energy. Just make ammonia instead.
    - mynameisvlad 8y ago
      > Another distraction. They don't matter as long as coal is being burned. Sure, let's kill off basically the only way to get things and people across the world. I'm sure that'll end up lovely.
- pentae 8y ago
Jupe 8y ago
"Climeworks has also opened a second facility in Iceland that can capture 50 tonnes of CO2 a year and bury it in underground basalt formations. " Taking Oxygen from our atmosphere (the gas we need to breathe) and pump it underground after we've combined it with Carbon seems like an atrociously bad idea. Taking CO2 out is only half the battle. We're going to need that oxygen. Pumping it into greenhouses seems better, but not very cost effective: You need to build these machines, then build the greenhouses, then transport tonnes of CO2 to the greenhouses... Seems much more cost effective to build windmills, solar arrays and the like!
- Symmetry 8y ago
  Earth's atmosphere is 20.946% O2 and .047% CO2. The amount of oxygen tied up in CO2 these days is really tiny.
jlebrech 8y ago
It would be cool to have a country which used the rest of the world's pollution to create it's own energy.
tamaharbor 8y ago
This machine does the work of six people. Unfortunately, it takes ten people to operate it.
dumbneurologist 8y ago
All of the skepticism here in the top comments is well-placed. This is basic thermodynamics: if you can burn fossil fuels to get energy/electricity, then putting the CO2 byproduct back into an inert form will cost exactly as much (or more; courtesy of the second law) as it would have to get that energy from a different source in the first place. There is no technology - now or ever - that will make "scrubbing" CO2 more economical than simply leaving the oil in the ground, and using renewable energy sources.
- bluGill 8y ago
  Not necessarily. A portion of the energy from burning fossil fuels comes from hydrogen reactions not carbon. How much - I have no idea.
- Zenbit_UX 8y ago
  Physics and thermodynamics don't actually use $ costs in their equations... e$ !== mc2 The costs you are referring to are in energy. It's entirely possible that the $ cost to put it back into the ground are cheaper than to get it out.
  - AstralStorm 8y ago
    Hmm, mostly depends on where you put it. Putting it into ocean would probably be add hard as getting it out of there. Except here we can put it into storage in a more convenient place. The real problem is that we do not have enough energy to run this yet. A bunch of nuclear plants would solve it but these come with political baggage. Unfortunately CO2 recovery is very local.
- jkqwzsoo 8y ago
  > This is basic thermodynamics: if you can burn fossil fuels to get energy/electricity, then putting the CO2 byproduct back into an inert form will cost exactly as much (or more; courtesy of the second law) as it would have to get that energy from a different source in the first place. > There is no technology - now or ever - that will make "scrubbing" CO2 more economical than simply leaving the oil in the ground, and using renewable energy sources. This is not true. There is no thermodynamic reason that the energy of splitting C(n)H(2n+2) + 2O(2) into water and carbon dioxide should have any connection to the energy of moving molecules of CO2 from location A to location B. If you were talking about carbon sequestration by turning it back into a hydrocarbon fuel, then yes. For carbon capture and storage, this line of thinking is wrong. Most of the CO2 sequestration strategies either rely on pressurization/containerization (PV energy is paltry compared to bond energy) or the formation of some carbonic acid ion (ionic bond energies are paltry compared to covalent bond energies). Now, there is an issue that CO2 is severely diluted by putting it into the atmosphere. The entropic effects of dilution have to be overcome to concentrate CO2. A back-of-the-envelope estimate puts the entropy of mixing CO2 (400 ppm) into air at around 0.62 J/K, so roughly 20.4 kJ/mole CO2 are required, at least, to return it to a pure state (just taking about 3820 moles of air + CO2 and turning it into 3819 moles of air + 1 mole of pure CO2). Burning a mole of methane will produce approximately 810 kJ of energy and 1 mole of CO2 (and 2 moles of water). So the energy produced by creating CO2 will be approximately 800,000 J/mole, while the energy required to separate CO2 at 400 ppm from the atmosphere will be approximately 20,000 J/mole. You could have a natural gas-fired CO2 concentrator (the Carbon Engineering process requires heat to regenerate their chemical absorbers, so you could get pretty high utilization of the heat of combustion) and it wouldn't be an issue. Again, this is because there's a huge difference in collecting CO2 versus breaking and forming chemical bonds. That implies that 1 mole of methane can be used to sequester less than 39 moles of CO2 from the air. Now, we assumed that we could direct energy 100% to CO2 capture (maybe not a bad assumption for a chemical "free energy" process like LiOH scrubbing), but I think it's safe to say at least that 1 mole of methane could power a plant that sequesters all of the CO2 it produces (1 mole) plus some extra. Now, I don't work in CO2 capture, but I work with membranes and liquid separation processes, which experience similar issues when you're trying to concentrate a dilute product. I expect that it's not the energy of the separation that's an issue, but rather the capital expense required to scale a CO2 capture plant to the desired CO2 capture rate (I would guess it'd have to be tonnes per day or higher) and maintaining sufficient air flow (about 2500 tonnes of air at average global CO2 concentration are required to produce 1 tonne of CO2, or about 2.1 million m^3 of air -- 1 tonne/day => 24.6 m^3/second/(tonne/day), which is quite a lot) to the capture media that makes the process expensive. There are plenty of chemical processes (maybe fifty trillion different amine scrubber chemistries/processes, hydroxides, zeolites, base-functional polymers and membranes) to work with. For reference, a 1 tonne/day plant would be equivalent to about negative 61 cars per year. So, it would be far more efficient to capture CO2 at the power plant than free-floating in air (this is what, e.g., chemical looping combustion attempts to achieve). That I'm aware, the two ways you could achieve this are by removing nitrogen on the inlet (N2-O2 separation, or O2 adsorption/desorption onto a selective adsorber), or removing nitrogen on the outlet (N2-CO2 separation). So while there are practical issues in CO2 capture which might be hard to overcome, the thermodynamics of CO2 capture does at least pass the "sniff test".
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btomtom5 8y ago
Are these machines cheaper than trees?
gustaf 8y ago
Y Combinator is actively looking for companies working on this. If you are working on this yoiu should consider applying. https://www.ycombinator.com/rfs/#carbon https://www.ycombinator.com/rfs/#carbon https://www.greentechmedia.com/articles/read/y-combinator-is-looking-for-carbon-removal-startups#gs.2Xq_2VI https://www.greentechmedia.com/articles/read/y-combinator-is... I'm the YC partner who wrote the RFS and have been pushing this. I also went to the first conference of Negative Emissions in world (I think) in Gothenburg, Sweden last month. It's clear that much of what is needed for this to work is coming together 1) Research on underground storage is in a great place 2) Climeworks and Carbon engineering + Klaus Lackner are the pioneering companies/researchers working on Direct-Air-capture and they've shown the technology works. 3) California recently/are currently implementing legislation that will allow companies up to $180 per ton carbon removed and sequestered. This should be more than enough to build a business doing this at scale. 4) Perhaps the most important timing question is the fast drop in energy costs driven by solar. Energy is the number once scaling cost-factor if you want to scale this up to have a material impact on the climate. Solar is the obvious choice here since there is barely any scaling costs once installed. California incentives also allows you place your installations anywhere in the world. Mojave desert would be a good place. What is needed right now is you guys. We need entrepreneurs and founders who want to start companies building both Direct-Air-Capture technology and sequestration technologies. I've met many investors over the last 6 months are looking actively to invest in these projects. If you are working on these technologies you can email me gustaf@ycombinator.com Two other great resources here are http://www.centerforcarbonremoval.org http://www.centerforcarbonremoval.org http://www.airminers.org http://www.airminers.org I'm convinced that whoever will build the most cost-effective way to remove carbon from the air will both have a shot at a $100B+ market while saving the earth at the same time. What could be more motivating?
- carapace 8y ago
  Do you have any interest in algae-based solutions? (Cf. my comment in this thread I just left: https://news.ycombinator.com/item?id=17268103 https://news.ycombinator.com/item?id=17268103 ) I've done some crude experiments and "back-of-the-envelope" calculations and I think there's "something there". FWIW)
carapace 8y ago
Bubblers and tubes of algae in the sun. The bubbles stir the algae to maximize growth. Add a few goldfish to help cycle nutrients[1]. You can get the algae so thick that a test stick (plastic spoon) can't be seen beyond a centimeter deep.[2] At this stage you can remove half of the algae each day and they'll regenerate within twenty-four hours.[3] The extracted algae biomass (mostly composed of atoms that used to be air or water) can be "upcycled" by feeding to higher organisms (fish, earthworms, etc.) or processed industrially for e.g. plastics, fuel, foodstuffs, whatever. Ah, here we go, a few people are doing it already: http://www.iflscience.com/environment/urban-algae-farm-gobbles-highway-air-pollution/ http://www.iflscience.com/environment/urban-algae-farm-gobbl... The important thing is it's cheap as heck and doesn't require fancy technology. [1] Goldfish eat algae. Few in the tank makes it a simple aquaculture system. [2] I looked for images of "tubes of algae in the sun" and most of them were transparent. If you can see through the tube you're doing it wrong. [3] If conditions are optimal, otherwise you might have to be happy with 35-40%.
- maxbond 8y ago
  I'm bullish on algae but you may want to adjust your expectations. If you have a photobioreactor, with algae growing too densely to see through, in the sun, with goldfish, you're probably going to cook your goldfish. You're talking about engineering an ecosystem, and it is fancy technology. pH, temperature, and salinity all need to be copacetic. There's a reason "everyone" does aquaponics with talapia and vascular plants. Aquaponic systems usually run at pretty abysmal water qualities, but talapia will live in mud and vascular plants don't mind having lots of nutrients in their water. Algae will have a hard time growing at that high density you're imagining if they're being shaded by murky brown water. Of course these systems will have pretty big algae blooms, but usually these are biofilms growing attached to the walls of the system, close to the surface. If you feed the algae to other organisms, they're going to die and that carbon is going to turn into methane, which is 23 times more powerful a greenhouse gas than CO2. There's also the matter of growing algae in tubes made of petroleum plastic. How much carbon went into mining & processing the petroleum, manufacturing your tubes, and transporting them out to where your facility is, 100 miles from the nearest Starbucks? How long will it take you to pay off that carbon debt? (If there's a biobased alternative I'd love to hear about it.) But there are solutions as well as problems. Aquaponic systems don't have to be directly coupled, for instance. And those biofilms are much denser than planktonic growth (ie tubes). My main "research" area (calling me a researcher would be too generous) is attached growth cultivation systems, for a lot of these same reasons. Pyrolysis can be used to turn the carbon into a biochar with very low bioavailability, solving the issue with methane. PS Just to clarify, bubbling doesn't maximize growth as much as keep the algae alive. Keeping high-density algae well mixed does ensure that everyone gets their turn to be in the sun. But algae can't survive in an anoxic environment, and without aeration a tall column of water will quickly become anoxic. The algae on the bottom will rot and you're back to converting CO2 into methane (which, in most systems, would come right out of the top of the tube). Additionally, aeration provides CO2; no CO2 would mean no photosynthesis.
mncolinlee 8y ago
Wouldn't it be likely that the greater than percentage of free CO2, the cheaper removing CO2 will get per ton? Trump's intransigence could make this technology viable.

531 points by kjeetgill 8y ago

Substantial conversation on reddit: https://www.reddit.com/r/science/comments/8pbuqv/sucking_carbon_dioxide_from_air_is_cheaper_than/ https://www.reddit.com/r/science/comments/8pbuqv/sucking_car...

tptacek 8y ago
The r/science conversation crushes the HN conversation and is worth skimming.

sremani 8y ago

This is good news, esp. given the context from this spectrum article why we need some technologies like these.. https://spectrum.ieee.org/energy/renewables/what-it-would-really-take-to-reverse-climate-change https://spectrum.ieee.org/energy/renewables/what-it-would-re...

advisedwang 8y ago

Apparently burning petrol releases about 2.31 kg of CO2 per liter. At 100 USD per tonne of CO2 it would cost 0.23 USD per liter of petrol if we captured every bit of CO2 released. That's within the realm of possibility.

jessaustin 8y ago
Yeah it seems pretty straightforward to just start taxing at that rate and be done with all the nonsense.
- njarboe 8y ago
  Except for the part that this process takes electricity to do. If the process can be turned off and on quickly, it would be a great use for excess wind and solar power.
  - ishjoh 8y ago
    One nice thing about this is that you could pull carbon out of the atmosphere from remote locations, in particular hydro electricity could provide abundant, inexpensive, and clean power.
    - njarboe 8y ago
      Just what I was thinking. Like west Texas with wind where electricity prices go negative quite often in the middle of the night.
      - DoctorOetker 8y ago
        guys, capturing CO2 or not releasing it at a power plant are the easy and cheap part. It's what you do with the voluminous CO2 gas. Converting to fuel will be very expensive (although if the conversion process can be throttled quickly, which I highly doubt, we could use peak solar and wind, and treat fuel as a battery). The figures you calculate is meaningless, factories could always have been fitted with carbon capture for a relatively low energy cost. The reason this is not done at scale is there is zero demand for CO2! (unless you pay someone carbon credits to pretend to need CO2!!!)
        linkregister 8y ago
        Yes, at that scale, the price of CO2 approaches zero, especially with the caveat that it shouldn't be reintroduced (as with carbonated beverages and pressurized machinery). Carbon dioxide sequestration or transformation is the next step. Getting the first step to be economical is also nice.
        njarboe 8y ago
        CO2 injection is already done in many oil fields for enhanced oil recovery. People already know how to pump it down into the earth and track where it goes. Put a decent price on removing CO2 from the atmosphere and people will quickly figure out how to do it for a nice profit. Lots of old oil wells in west Texas also.
- 8xde0wcNwpslOw 8y ago
  A funny coincidence: the excise duty on petrol here consists of several "parts", one of which is the carbon dioxide tax, which is currently about 0.25 USD/litre (in total the fixed taxes amount to a bit over 1 USD/litre).
  - pbhjpbhj 8y ago
    I assume "here" is USA, but you could be converting to dollars from local currency?
    - 8xde0wcNwpslOw 8y ago
      I'm converting because earlier messages used dollars as well. I doubt that taxes that high exist anywhere in the US (1 USD/litre being almost 4 USD/gallon after all).
lifeisstillgood 8y ago
Well that's a Holy Fuck moment for me. I thought the parent here had made a off-by-orders of magnitude error - how can a liter of petrol (which itself is only a kg) produce 2.31kg of CO2 ... i mean work it out, all the carbon would have to attach to 2x oxygen ... ok that might just ... err ... see this reference for a walk through of the calculation - http://ecoscore.be/en/info/ecoscore/co2 http://ecoscore.be/en/info/ecoscore/co2 Every time I pour petrol into my tank I am basically pouring twice that weight of CO2 into the atmosphere. I may be very dumb but I never thought if it like that before. I always assumed CO2 was a minor byproduct ... but like breathing. oh dear.
- ChrisLomont 8y ago
  Consider it this way. That entire liter turns to gas when burned, and in doing so it combines with O2 and other things in the air, resulting in the total weight of the liter + what it combined with entering the air.
- voidmain 8y ago
  > like breathing When you eat 1kg of peanut butter, if I've done my math right, you'll breathe out about 2.3kg of CO2. Dry cereal would be about 1.5kg. Most foods have a lot of water in them, though.
  - lifeisstillgood 8y ago
    Darn and that looked like a pretty decent breakfast :-)
  - dTal 8y ago
    I would think you're unlikely to produce sufficient bile to metabolise an entire kilogram of peanut butter at once. Most likely you'd get really nasty, oily runs at best, and quite possibly throw up.
- njarboe 8y ago
  Yes, but the weight of the oxygen is in the atmosphere already. And for a bonus, all the hydrogen you burn removes O2 from the atmosphere in the form of water, reducing the weight of the atmosphere (and therefor the greenhouse effect of the atmosphere). How much the reduction of O2 from H burning offsets the transformation of O2 to CO2 is left as a problem for the reader. If anyone knows of a paper that discusses this effect, I'd love to read it.
ebbv 8y ago
You are making the big assumption this article is accurate and scalable. I’m not so sure. You’re also assuming that capturing everything scales linearly from capturing something.
- sunstone 8y ago
  Bill Gates has been funding this project since its inception and one of the founders is a world expert in global warming and a Professor at Harvard so you'll have to do better than unsubstantiated innuendo here. Roll out some real facts rather just than pulled out of your ear guesses.
  - ebbv 8y ago
    You realize the argument you’re making (“Smart people are backing this!”) is exactly how Theranos and many other scams go on as long as they do right? All I did was bring up some concerns. I did not state any facts, merely point out details that need to be addressed. Chill out.
    - sunstone 8y ago
      This may give you some reassurance.[1] [1]https://arstechnica.com/science/2018/06/machines-that-suck-co%E2%82%82-from-the-air-might-be-cheaper-than-we-thought/ https://arstechnica.com/science/2018/06/machines-that-suck-c...
      - ebbv 8y ago
        Why would it? It’s just another one sided fluff piece. Basically a press release for the product much like the original article.
sunstone 8y ago
Yes, I would happily pay that for "carbon neutral" gas.
- JetSpiegel 8y ago
  Considering the US has literally entered wars that cost trillions over oil disputes, I think you are pretty much alone.
  - ISL 8y ago
    Counter-example: I'd happily pay at least that much for carbon-neutral or carbon-reducing fuel. Source: Am registered-voter citizen of the United States.
    - JetSpiegel 8y ago
      I'm not disputing that, just the the political climate makes that opinion a miniscule minority.
  - JanisL 8y ago
    Sounds like others are paying a fairly high price in that case but just more indirectly
NovaS1X 8y ago
This is a mind blowing concept. I mean, it makes sense when I read: http://ecoscore.be/en/info/ecoscore/co2 http://ecoscore.be/en/info/ecoscore/co2 But does this take into account catalytic converters or other emissions controls? Cats take the CO from the combustion process and turn it into CO2, the gas you're referencing. I'd just like to clarify because this is a big revelation in my way of thinking about pollution. Are we really releasing that much CO2 post emissions controls?
- jaggederest 8y ago
  Emissions controls have no effect at all on CO2 emissions. They don't alter the fundamental stoichiometry of a pure octane combustion: 2C8H18 + 2502 -> 16CO2 + 18H2O So yes, burning a liter of octane (6 moles) will use ~1600 liters of oxygen and emit ~1000 liters of carbon dioxide, or a little over two kilograms. In pure carbon terms, it produces (drumroll) the exact same amount as the input: 49 moles at 12 g/mol or 590 grams.

pier25 8y ago

Doing a little math... Considering 1100 Gtons in the atmosphere and $200 per ton would be roughly $220 trillions. The current world's GDP is $78 trillions. Even if the world invested $10 trillions every year it would still take 20 years to remove all the carbon emitted between 1850 and today. Of course we would keep pumping about 37 Gtons per year (and growing). https://www.carbonbrief.org/analysis-global-co2-emissions-set-to-rise-2-percent-in-2017-following-three-year-plateau https://www.carbonbrief.org/analysis-global-co2-emissions-se...

jessaustin 8y ago
Maybe the first goal could just be removing the current year's production? That would still be a vast improvement over every other proposed solution.
- Scarblac 8y ago
  By his numbers that's still ~ $7.4 trillion, or about 10% of the world's GDP. And it doesn't include storing the captured CO2 anywhere permanent. I think it's a lot more practical to reduce our emissions to close to zero, hard as that is.
  - jessaustin 8y ago
    Anything we do is going to be expensive. "Stopping all use of fossil fuels" like you suggest would also be very expensive, even if we ignore obvious costs like disposing of all the corpses created by such an endeavor.
epistasis 8y ago
20 years is an incredibly quick timespan in which to do this. If we can become carbon neutral by 2040 and carbon negative after, we can stave off many of the worst parts of climate change.
- padobson 8y ago
  I'm with you. I have to believe a joint country climate accord where member nations pledge to suck X gigatonnes of carbon from the atmosphere (or finance those that do) is a much easier political sell than 1) taxing fossil fuel companies/cartels or 2) enforcing emissions restrictions on various industries. Cleaning up 150 years of emissions in 20 or 40 or even 60 years seems like a miracle on par with the moon landing or eradicating smallpox.

User23 8y ago

I worry that well-meaning efforts at mass climate engineering will cause far more harm than letting nature run her course. I'm not convinced there is a causal relationship between human activity and CO2 levels or average temperatures (ignoring urban heat island and similar effects). Sure there is a correlation, but we all know what that means. The kind of atmospheric engineering that scares me is exactly the tool that would be required to show a causal relationship. Another point of concern is that none of the doom and gloom predictions are made by any climate model. All a climate model can do is make predictions about, well, climate. It takes an economic or some other sociological model to predict how that change in climate will affect human beings and societies, and what the costs (and benefits!) will be. Even if you trust the climate models 100% you'd be a fool to trust the economic or sociological models. How can one rationally justify an intervention is worth the cost when one can't know the cost of what is being prevented?

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epistasis 8y ago
You have a lot of strange beliefs. Can you back any of them to the degree that you demand of others? Have you considered taking a skeptical approach, and looking at the arguments that you disagree with a prior? I suspect that once you do, you will be more than convinced about, e.g. humans having increased CO2 levels. If you are not convinced of even that basic fact after looking at the evidence, I would suggest that there is not evidence at all that could change your mind. I.e. this is a religious or political conviction rather than an evidence based belief. The idea that CO2 level rises is not due to human activity is as far out there as saying you've invented a perpetual motion machine. Honestly.
- User23 8y ago
  I believe I am taking the skeptical approach. I've read a lot on the subject and most of what I find is appeals to fear and other emotions, for example that climate change is going to destroy the earth. Actually the Earth did quite well during the carboniferous period all things considered. Maybe human activity is responsible for the increase in CO2. I don't deny that. They are correlated. I accept that. But maybe there is a third variable or combination of variables that is driving CO2 levels? Is that really so unreasonable. It seems awfully anthropocentric and, honestly, arrogant, to assume that human activity is the only thing that affects atmospheric composition. Perhaps you should take your own advice? > The idea that CO2 level rises is not due to human activity is as far out there as saying you've invented a perpetual motion machine. Honestly. No it isn't. Also, I never positively stated that it isn't.

maxander 8y ago

Remember that, a priori, you should be far more skeptical of studies with this sort of result than, say, studies showing that neocortinoids don't harm bees or that the latest blockbuster pharmaceutical has no side effects. The sheer mass of money in position to lobby for the "fossil fuel use is fine!" position dwarfs that of all other financially-fraught research questions put together. To wit; the company behind the paper in question, Carbon Engineering, is noted by Wikipedia as having "oil sands financier N. Murray Edwards" as one of it's principal backers. And the article's "outside expert's opinion" quote comes from Stephen Pacal, co-director of the Carbon Mitigation Initiative at Princeton- which has an "extended partnership with BP" worth a great deal of money [1]. The financial conflicts behind this research are staggering. [1] https://www.princeton.edu/news/2010/11/18/carbon-mitigation-initiative-receives-11-million-through-extended-partnership-bp https://www.princeton.edu/news/2010/11/18/carbon-mitigation-...

zzzeek 8y ago
this is kind of interesting as there's some reverse/upside down ideas that come out of it: 1. the big oil companies and the massive political machine that supports them drops the whole "global warming isn't real" line, no more snowballs being taken in to congress and all that. Because now they can just say they'll suck it out of the air and they can continue to think they can keep burning all the coal and oil they want (which of course they should not). Once everyone is on the same page that global warming is real, they can't go back on that. If the approach here proves to be insufficient (which it probably is), a lot of political points have been scored in any case. 2. the machinery to suck out the CO2 is another big "green" industry, like solar or wind, but doesn't compete with oil/coal! it's meant to mitigate the damage they do. So as you've noted, way more money and attention might end up going here, increasing the chance of its viability. 3. No matter what happens with the rate of burning oil/coal, we need this anyway. There's consensus that we're pretty much over the point of no return with warming due to all the ice that has melted, and if the permafrost goes that might be catastrophic.
- briandear 8y ago
  Is anyone actually debating if climate change is happening? The debate is on the degree of human influence.

deleted 8y ago

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Tloewald 8y ago

Let's take this article at its word, which is that right now we can bury carbon for $600/tonne (forget the speculative $100/tonne) which equates to $1.32/liter of gas (based on the speculative $0.22/liter). In California right now gas costs ~$4/gallon (which is high compared to most of the US but low compared to most of the developed world), so it's not an insane amount to pay for carbon-neutral gas. The interesting thing to me is that this is presumably something ideal to do with excess solar power (e.g. it's a much better deal than paying other states to use it, which is what California is currently doing). Another question is how does this compare, price-wise, to using solar power to create fuel (e.g. hydrogen) and truck it around the way we do with gas.

DrTung 8y ago

In a few years I'll probably have grandkids and when I read this, think it increases the chance that those kids will still be able to go to Disney World in Florida, i.e. it will not be submerged.

jonknee 8y ago
FWIW either way they will be able to visit, Orlando is not on the coast and is ~100' above sea level.
kirubakaran 8y ago
Don't worry, they'll move Disney World to dry land.
mikec3010 8y ago
By that time Disney world will just be a VR app you load on your 8k VirtualStation via fiber optic link with others. Disney will long have replaced all their parks with simulation because focus groups found that while consumers preferred the real park, the amount of lost park sales was less than the gains of zero liability, shutting down the park and firing those employees who were eating into shareholder profits. The park now only exists as a museum and luxury apartment homes, with paid autonomous bus tours.

blacksqr 8y ago

They say they can make synthetic fuel at $1/liter with CO2 input at $100/ton. There's plenty of CO2 available commercially at about $20/ton. If they can make synthetic fuel economically out of CO2, they should be doing that RIGHT NOW, not waiting until they've perfected the air extraction process. They could use the money they made from the fuel to speed up R&D on the extraction process.

Robotbeat 8y ago

Good. Then we should immediately require fossil fuel companies to do this or pay for someone else to do it as well as long-term storage and insurance for the storage.

theptip 8y ago

> The result, after further processing, is a calcium carbonate pellet that can be heated to release the CO2. That CO2 could then be pressurized, put into a pipeline and disposed of underground. I'm curious why you wouldn't just bury the calcium carbonate pellets at this point (or sell them, since they have value). Pumping CO2 underground isn't a cheap or reliable process yet as far as I can tell. > the company is planning instead to use the gas to make synthetic, low-carbon fuels. I suppose the answer is that the synthetic natural gas is more valuable than the calcium carbonate. Seems like adding more steps than strictly necessary though. Edit: > In the United States, Carbon Engineering is eyeing a recently expanded subsidy for carbon capture and sequestration, which could provide a tax credit of $35 per tonne for atmospheric CO2 that is converted into fuels. Missed this bit in the article. Regulatory arbitrage, which is a very good reason to add another step in your process, even if it's not strictly optimal.

codefined 8y ago
I haven't done chemistry in years, but I think you can fairly easily reuse the calcium carbonate pellet once it has been heated. I imagine the cost of energy is significantly less than the cost of the raw resources.
scythe 8y ago
>I'm curious why you wouldn't just bury the calcium carbonate pellets at this point Potassium hydroxide absorbs carbon dioxide: 2 KOH + CO2 >> K2CO3 + H2O Calcium oxide regenerates potassium hydroxide: CaO + K2CO3 + H2O >> CaCO3 + 2 KOH Calcium oxide is recovered by heating: CaCO3 + heat >> CaO + CO2
mikec3010 8y ago
Why go that far? Why not grow acres of a hardy fast growing plant like hemp or seaweed, fertilized with sewage water. Harvest and dry the plant, bale it, and stack the bales underground? Or the Midwest farmers could bale their corn waste bury it instead of burning it. Arizona could pipe in seawater and grow seaweed by the ton.

exabrial 8y ago

I'm curious how this competes with a bunch of algae in a lake

ajnin 8y ago

Based purely on numbers CO2 capture seems like a plausible idea. The article cites a cost of $0.22 cents per liter of fuel to capture an equivalent amount of CO2. Based on the current 93 million bbl or roughly 15 billion liters of oil consumed every day worldwide, the cost would be around 1.2 Trillion USD per year, or 1.5% of the global GDP. A lot but within the real of feasibility. However to achieve that in practice we would need to build enough CO2 capture plants to capture the CO2 released by all human activity, and we've been building machines that release CO2 for decades. The effort to catch up is immense. The similar company Climeworks, cited in the article, has an example of such a plant here : http://www.climeworks.com/our-products/ http://www.climeworks.com/our-products/. The DAC-18 variant, which looks like the prototype that they actually built, it is a complex 3 stories high structure with 90m^2 of ground area, and according to the product page it can capture 2460 kg per day, although that is probably under ideal conditions and in practice it could be considerably less. According to a quick search we released around 36.75 Gt of CO2 last year. To capture that, we would need to build 36.75e12/365/2460 = 41 million such plants, at the bare minimum. And that would be only break even, we'd need even more to start capturing the excess CO2 already in the atmosphere. That seems unrealistic.

sjg007 8y ago
Well, we could plant more trees, not deforest the Amazon.. Maybe grow some algae or something too.

WalterBright 8y ago

Probably the most cost-effective way of sucking CO2 out of the air is planting trees on a huge scale.

cbHXBY1D 8y ago
A user on reddit did some napkin math on the r/science submission of this article. The tl;dr is we don't have enough land area for the amount of trees needed to sequester 1,100 gt of carbon. https://www.reddit.com/r/science/comments/8pbuqv/sucking_carbon_dioxide_from_air_is_cheaper_than/e0aendn/ https://www.reddit.com/r/science/comments/8pbuqv/sucking_car...
- BurningFrog 8y ago
  If you read it closely, it says we can't do it in one year, which seems overambitious...
- WalterBright 8y ago
  Trees can't do it all, but they can help a lot and are cheap and we like trees!
krzat 8y ago
We should GMO a plant that spreads in the dessert and produces energy heavy fruit (probably nuts) that can be buried. Or maybe a tree that grows super deep and thick roots.

hmwhy 8y ago

Economics and policies aside, I’m a bit skeptical about the approach described in that article regarding the use of potassium hydroxide (production, transportation) and it’s subsequent processing (to re-release the captured carbon dioxide, somehow transform it into fuel, and let people release again!?); even just the logistics would most likely be releasing a good amount of CO2 if cost is such a huge factor in this. It just feels like the carbon dioxide released would be a substantial offset to that captured. Ultimately, it would still be viable if the net outcome is a reduction in atmospheric carbon dioxide; but I’m not convinced, at least with the approach in question, that humanity’s interest is at the top of the list. It would be absolutely fantastic and very much appreciated if someone who knows about the actual “accounting” of carbon dioxide in this type of carbon sequestration technology can comment.

fallingfrog 8y ago

The thermodynamics of this seems wrong to me. You would have to burn at least a ton of oil to draw a ton of carbon from the air, probably more like 2 tons due to inefficiencies. The cost of oil is 418 dollars a ton. So to make this even remotely plausible you have to assume access to an energy source which is 4 times cheaper than oil on a cost basis. So cheap, in fact, that unburning carbon from the air would be twice as cheap as mining it out of the ground.

snarf21 8y ago
Let's say the thermodynamics are wrong. At some level, it doesn't matter by how much. I think of this like a battery. Use wind power or tides even solar to create this gas. Then you have easy to transport energy that is carbon neutral as you've added no new CO2 to the air. That is the excitement, not the cost per unit of energy.
RockyMcNuts 8y ago
hypothetically, if you burn 2 tons of oil and you get out of the atmosphere 1 ton of oil equivalent to burn, then if your emission-free energy cost is 1/2 the price of oil, you break even on cost, and reach carbon neutral, no? Alternatively, if your emission-free energy cost is same as oil, you tax oil-based energy 100% and now you reach carbon-neutral? I don't see why it has to be 4x cheaper, clarification would be helpful.
- DoctorOetker 8y ago
  he's estimating the energetic i.e. objective cost. If the government subsidized to the point of us stopping pumping up oil or true fossil neutral rate (ignoring the CO2 already up there, which will over hundreds of years fall back to natural levels), then we would have to manufacture our fuels... with what energy? sure in the long term I think we can use renewable, but it isn't deployed yet. The only way this makes sense is if we deploy true renewable energy, and stop allowing fossil fuel industry to masquerade as green.
ISL 8y ago
The majority of the mass (72%) of CO2 is oxygen, not carbon. By convention, the "tons" generally quoted in climate literature are carbon-dioxide, not pure carbon. Using $418/ton of oil: $418 * (1-0.72) = $117, in striking range of the $100 target. Where renewables match or exceed hydrocarbon fuel, $100 would appear to be a reasonable price.

danschumann 8y ago

The problem of climate change is the same as the obesity problem, if you phrase it like this: "There is something that is going to kill you in 20 years if you don't change your habits today". Most people wait until they have a significant event (heart attack, they can't get up the stairs without being out of breath, etc) until they change. I always figured it would take some sort of big event for people to change, and then when that happened, we would start working on retroactive fixes ( like sucking co2 out of the air ), rather than preventative fixes.

jillesvangurp 8y ago

Here's a related article that circulated in finnish media a few days ago: https://yle.fi/uutiset/osasto/news/finnish_researchers_use_air_solar_power_to_create_renewable_hydrocarbon/9661164 https://yle.fi/uutiset/osasto/news/finnish_researchers_use_a... This is about the apparent work of a Finnish researcher to come up with a scalable way to produce fuel from air such that it can be done locally. Think gas stations producing their own gas. Right now this would be relatively expensive because of energy cost but as those drop and the technology is improved, that cost can go down. Stuff like this not surprising for anyone that has followed news around renewables lately and a very cool side effect of the fact that renewable energy prices have been dropping exponentially for quite some time now combined with the fact that the cost of lots interesting chemical processes are primarily driven by how much energy is required. As energy becomes cheaper, those chemical processes become more feasible and the demand for more energy causes people to invest in making that cheaper further. The same economic dynamic that is causing us to destroy our planet is also producing the solutions for saving it. For example, producing clean water is a trivial process if you have cheap energy. This is why desalination plants are popping up in lots of places where clean water is scarce and they tend to be paired with wind/solar plants. You can also produce fuels out of water and the resulting fuels, whether it is hydrogen or hydrogen peroxide, are useful ways of storing energy. Oil is a scarce resource that is hard to procure and therefore relatively expensive. If there's an energy intensive way to produce oil from CO2, that's great news because that means it's just a matter of time before the price of that energy drops enough to make that worthwhile. Things like this can go from being too expensive to only slightly more expensive to being magnitudes cheaper in the near future. What I love about this is that climate change can be countered with simple economics rather than idealism. Once we stop pumping new co2 in the atmosphere for cost reasons because we found a more cost effective way to just suck it from the atmosphere, nature will do it's thing and help us revert the effects of the past centuries. We don't actually need to actively clean up the atmosphere, our planet is fully capable of doing that by itself given enough time. Also worth pointing out that oil is used for more than just fuel. So, stuff like this is relevant even if we switch to electric vehicles. We still need to produce plastics and other materials. All of that can in principle be done with co2 harvested straight from the air as well.

Reason077 8y ago

It seems like at $94/ton CO2, we're still a long way from where this becomes viable. At that price, to offset humanity's annual 36 Gt CO2 emissions (36 billion tons) we'd need to spend about $3.2 trillion. Per year. Surely the cost of reducing CO2 emissions - the cost of upgrading emissions sources to alternative, lower-carbon technologies - is much less than $94/ton. And that's where we should be focusing our efforts and funding for the foreseeable future.

erikig 8y ago

Yep, just plant a tree or two ;)

cvaidya1986 8y ago

What if we all plant 2 trees each in our lifetime?

AtlasBarfed 8y ago

Soooo, around $100/ton. And google says we currently pump 40 billion tons per year. Let's ballpark: average 5 billion per year for 100 years. 500 billion excess tons. 50 trillion dollars to remove what we've already polluted. + 4 trillion per year to offset what we're at already. Yeah, nothing about that is "cheap". Maybe... slightly less astronomically expensive. And a lot of cheap carbon capture is "pump it into the ground", which, while I'm not a geologist, but I'm guessing the petroleum folks aren't looking to hard for leaks back into the atmosphere. But given those numbers, greening the sahara seems like a much better approach than any industrial approach.

selimnairb 8y ago

Unless we stop burning fossil carbon, pulling carbon out of the atmosphere to create fuels that we will then burn makes zero sense, in terms of mitigating climate change; even if we used solar energy to do this, there would be no net decrease in carbon in the atmosphere. This only makes sense if we use a carbonless energy source and “permanently” sequester the carbon somehow.

FrozenVoid 8y ago

Its not profitable to clean: even if cleaning was paid for by the government, most cleaning efforts would be commercial enterprises simulating maximum cleaning effort(like the incentive to collect rat tails will result in rat breeding farms, the "environment cleaning industry" will be most profitable with more pollution and costlier cleaning incentives/bonuses ). It will result in encouraging more pollution and removing all safeguards(clean coal? we'll clean it up later!) towards a new industry whose main interest would be preserving pollution forever to profit from cleaning it up. Like a pharmaceutical industry, the symptoms are more profitable than curing the disease completely.

rdiddly 8y ago

What's that old saying... usually misattributed to Einstein... you can't solve a problem using the same frame of mind that created it? We have a problem of too much CO2 caused by massive deployment of complex, energy-intensive industrial facilities and processes, and they want to fix it using a fairly complex and energy-intensive industrial facility/process (with giant air blowers and all), that itself is dependent on other complex industrial processes for its manufacture, transport, construction and operation. And perpetual energy use to run the fans... I mean? Are we sure it's a net positive CO2 capture after all that? And if so, is it still a net positive after the CO2 they've captured is turned (by means of even more energy input) into "low carbon fuels" that are then burned, releasing CO2 back into the atmosphere? I mean it's great if it works and all. I just feel like the real solution doesn't look like this.

lastUsername 8y ago

"The Paris Agreement’s inclusion of 1.5°C has catalysed fervent activity amongst many within the scientific community keen to understand what this more ambitious objective implies for mitigation. However, this activity has demonstrated little in the way of plurality of responses. Instead there remains an almost exclusive focus on how future ‘negative emissions technologies’ (NETs) may offer a beguiling and almost free “get out of jail card”. This presentation argues that such a dominant focus, evident for 2 and 1.5°C, reveals an endemic bias across much of the academic climate change community determined to voice a politically palatable framing of the mitigation landscape – almost regardless of scientific credibility." Please read: https://kevinanderson.info/blog/duality-in-climate-science/ https://kevinanderson.info/blog/duality-in-climate-science/ The problem here is cultural, not scientific. Real science about climate change is not politically palatable, NETs represent an easy way out.

frockington 8y ago
And if we were trying to do real science we'd have to actually find proof of cause and effect. I still have yet to find convincing proof that CO2 is the culprit. Te level of CO2 in the ar should be addressed, but I am worried that we have culturally painted CO2 as such a bad guy that the underlying cause of global warming will never be found

08-15 8y ago

So they are talking about a plant, soon to be built, that will capture about 50.000 tons of CO2 per year. Amazing! A single coal fired power plant (1GW) emits 12 million tons of CO2 per year. Seriously, this stuff won't work, and it's pointless as long as fossil fuels are burned somewhere on Earth. It's bloody obvious what to do instead: (1) stop burning coal for electricity, (2) stop burning methane ("natural" gas) for electricity, (3) stop burning methane for process heat, (4) stop using methane to make fertilizer, (5) use electrified railways instead of trucks for most transportation. Then it makes sense to talk about synthetic fuels, CO2 capture, electrifying the remaining transportation, etc, but not before.

mhandley 8y ago
I agree about the priorities. But to do what you suggest, to the extend that it needs to be done, we need much better ways to cope with variability of renewables. We probably need a whole range of energy storage solutions; no single one will be sufficient. And then there are aviation and shipping, neither of which is going electric any time soon. So starting work on using excess power when renewables are over-generating to capture CO2 and using it to make carbon-neutral liquid fuels seems to also be a key part of the long-term picture.
- 08-15 8y ago
  > aviation and shipping Another distraction. They don't matter as long as coal is being burned. > renewables are over-generating Even then, trying to capture a trace gas is the dumbest thing anyone could attempt. Especially if the process involves calcining lime---what a ridiculous waste of energy. Just make ammonia instead.
  - mynameisvlad 8y ago
    > Another distraction. They don't matter as long as coal is being burned. Sure, let's kill off basically the only way to get things and people across the world. I'm sure that'll end up lovely.
pentae 8y ago

Jupe 8y ago

"Climeworks has also opened a second facility in Iceland that can capture 50 tonnes of CO2 a year and bury it in underground basalt formations. " Taking Oxygen from our atmosphere (the gas we need to breathe) and pump it underground after we've combined it with Carbon seems like an atrociously bad idea. Taking CO2 out is only half the battle. We're going to need that oxygen. Pumping it into greenhouses seems better, but not very cost effective: You need to build these machines, then build the greenhouses, then transport tonnes of CO2 to the greenhouses... Seems much more cost effective to build windmills, solar arrays and the like!

Symmetry 8y ago
Earth's atmosphere is 20.946% O2 and .047% CO2. The amount of oxygen tied up in CO2 these days is really tiny.

jlebrech 8y ago

It would be cool to have a country which used the rest of the world's pollution to create it's own energy.

tamaharbor 8y ago

This machine does the work of six people. Unfortunately, it takes ten people to operate it.

dumbneurologist 8y ago

All of the skepticism here in the top comments is well-placed. This is basic thermodynamics: if you can burn fossil fuels to get energy/electricity, then putting the CO2 byproduct back into an inert form will cost exactly as much (or more; courtesy of the second law) as it would have to get that energy from a different source in the first place. There is no technology - now or ever - that will make "scrubbing" CO2 more economical than simply leaving the oil in the ground, and using renewable energy sources.

bluGill 8y ago
Not necessarily. A portion of the energy from burning fossil fuels comes from hydrogen reactions not carbon. How much - I have no idea.
Zenbit_UX 8y ago
Physics and thermodynamics don't actually use $ costs in their equations... e$ !== mc2 The costs you are referring to are in energy. It's entirely possible that the $ cost to put it back into the ground are cheaper than to get it out.
- AstralStorm 8y ago
  Hmm, mostly depends on where you put it. Putting it into ocean would probably be add hard as getting it out of there. Except here we can put it into storage in a more convenient place. The real problem is that we do not have enough energy to run this yet. A bunch of nuclear plants would solve it but these come with political baggage. Unfortunately CO2 recovery is very local.
jkqwzsoo 8y ago
> This is basic thermodynamics: if you can burn fossil fuels to get energy/electricity, then putting the CO2 byproduct back into an inert form will cost exactly as much (or more; courtesy of the second law) as it would have to get that energy from a different source in the first place. > There is no technology - now or ever - that will make "scrubbing" CO2 more economical than simply leaving the oil in the ground, and using renewable energy sources. This is not true. There is no thermodynamic reason that the energy of splitting C(n)H(2n+2) + 2O(2) into water and carbon dioxide should have any connection to the energy of moving molecules of CO2 from location A to location B. If you were talking about carbon sequestration by turning it back into a hydrocarbon fuel, then yes. For carbon capture and storage, this line of thinking is wrong. Most of the CO2 sequestration strategies either rely on pressurization/containerization (PV energy is paltry compared to bond energy) or the formation of some carbonic acid ion (ionic bond energies are paltry compared to covalent bond energies). Now, there is an issue that CO2 is severely diluted by putting it into the atmosphere. The entropic effects of dilution have to be overcome to concentrate CO2. A back-of-the-envelope estimate puts the entropy of mixing CO2 (400 ppm) into air at around 0.62 J/K, so roughly 20.4 kJ/mole CO2 are required, at least, to return it to a pure state (just taking about 3820 moles of air + CO2 and turning it into 3819 moles of air + 1 mole of pure CO2). Burning a mole of methane will produce approximately 810 kJ of energy and 1 mole of CO2 (and 2 moles of water). So the energy produced by creating CO2 will be approximately 800,000 J/mole, while the energy required to separate CO2 at 400 ppm from the atmosphere will be approximately 20,000 J/mole. You could have a natural gas-fired CO2 concentrator (the Carbon Engineering process requires heat to regenerate their chemical absorbers, so you could get pretty high utilization of the heat of combustion) and it wouldn't be an issue. Again, this is because there's a huge difference in collecting CO2 versus breaking and forming chemical bonds. That implies that 1 mole of methane can be used to sequester less than 39 moles of CO2 from the air. Now, we assumed that we could direct energy 100% to CO2 capture (maybe not a bad assumption for a chemical "free energy" process like LiOH scrubbing), but I think it's safe to say at least that 1 mole of methane could power a plant that sequesters all of the CO2 it produces (1 mole) plus some extra. Now, I don't work in CO2 capture, but I work with membranes and liquid separation processes, which experience similar issues when you're trying to concentrate a dilute product. I expect that it's not the energy of the separation that's an issue, but rather the capital expense required to scale a CO2 capture plant to the desired CO2 capture rate (I would guess it'd have to be tonnes per day or higher) and maintaining sufficient air flow (about 2500 tonnes of air at average global CO2 concentration are required to produce 1 tonne of CO2, or about 2.1 million m^3 of air -- 1 tonne/day => 24.6 m^3/second/(tonne/day), which is quite a lot) to the capture media that makes the process expensive. There are plenty of chemical processes (maybe fifty trillion different amine scrubber chemistries/processes, hydroxides, zeolites, base-functional polymers and membranes) to work with. For reference, a 1 tonne/day plant would be equivalent to about negative 61 cars per year. So, it would be far more efficient to capture CO2 at the power plant than free-floating in air (this is what, e.g., chemical looping combustion attempts to achieve). That I'm aware, the two ways you could achieve this are by removing nitrogen on the inlet (N2-O2 separation, or O2 adsorption/desorption onto a selective adsorber), or removing nitrogen on the outlet (N2-CO2 separation). So while there are practical issues in CO2 capture which might be hard to overcome, the thermodynamics of CO2 capture does at least pass the "sniff test".

deleted 8y ago

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btomtom5 8y ago

Are these machines cheaper than trees?

gustaf 8y ago

Y Combinator is actively looking for companies working on this. If you are working on this yoiu should consider applying. https://www.ycombinator.com/rfs/#carbon https://www.ycombinator.com/rfs/#carbon https://www.greentechmedia.com/articles/read/y-combinator-is-looking-for-carbon-removal-startups#gs.2Xq_2VI https://www.greentechmedia.com/articles/read/y-combinator-is... I'm the YC partner who wrote the RFS and have been pushing this. I also went to the first conference of Negative Emissions in world (I think) in Gothenburg, Sweden last month. It's clear that much of what is needed for this to work is coming together 1) Research on underground storage is in a great place 2) Climeworks and Carbon engineering + Klaus Lackner are the pioneering companies/researchers working on Direct-Air-capture and they've shown the technology works. 3) California recently/are currently implementing legislation that will allow companies up to $180 per ton carbon removed and sequestered. This should be more than enough to build a business doing this at scale. 4) Perhaps the most important timing question is the fast drop in energy costs driven by solar. Energy is the number once scaling cost-factor if you want to scale this up to have a material impact on the climate. Solar is the obvious choice here since there is barely any scaling costs once installed. California incentives also allows you place your installations anywhere in the world. Mojave desert would be a good place. What is needed right now is you guys. We need entrepreneurs and founders who want to start companies building both Direct-Air-Capture technology and sequestration technologies. I've met many investors over the last 6 months are looking actively to invest in these projects. If you are working on these technologies you can email me gustaf@ycombinator.com Two other great resources here are http://www.centerforcarbonremoval.org http://www.centerforcarbonremoval.org http://www.airminers.org http://www.airminers.org I'm convinced that whoever will build the most cost-effective way to remove carbon from the air will both have a shot at a $100B+ market while saving the earth at the same time. What could be more motivating?

carapace 8y ago
Do you have any interest in algae-based solutions? (Cf. my comment in this thread I just left: https://news.ycombinator.com/item?id=17268103 https://news.ycombinator.com/item?id=17268103 ) I've done some crude experiments and "back-of-the-envelope" calculations and I think there's "something there". FWIW)

carapace 8y ago

Bubblers and tubes of algae in the sun. The bubbles stir the algae to maximize growth. Add a few goldfish to help cycle nutrients[1]. You can get the algae so thick that a test stick (plastic spoon) can't be seen beyond a centimeter deep.[2] At this stage you can remove half of the algae each day and they'll regenerate within twenty-four hours.[3] The extracted algae biomass (mostly composed of atoms that used to be air or water) can be "upcycled" by feeding to higher organisms (fish, earthworms, etc.) or processed industrially for e.g. plastics, fuel, foodstuffs, whatever. Ah, here we go, a few people are doing it already: http://www.iflscience.com/environment/urban-algae-farm-gobbles-highway-air-pollution/ http://www.iflscience.com/environment/urban-algae-farm-gobbl... The important thing is it's cheap as heck and doesn't require fancy technology. [1] Goldfish eat algae. Few in the tank makes it a simple aquaculture system. [2] I looked for images of "tubes of algae in the sun" and most of them were transparent. If you can see through the tube you're doing it wrong. [3] If conditions are optimal, otherwise you might have to be happy with 35-40%.

maxbond 8y ago
I'm bullish on algae but you may want to adjust your expectations. If you have a photobioreactor, with algae growing too densely to see through, in the sun, with goldfish, you're probably going to cook your goldfish. You're talking about engineering an ecosystem, and it is fancy technology. pH, temperature, and salinity all need to be copacetic. There's a reason "everyone" does aquaponics with talapia and vascular plants. Aquaponic systems usually run at pretty abysmal water qualities, but talapia will live in mud and vascular plants don't mind having lots of nutrients in their water. Algae will have a hard time growing at that high density you're imagining if they're being shaded by murky brown water. Of course these systems will have pretty big algae blooms, but usually these are biofilms growing attached to the walls of the system, close to the surface. If you feed the algae to other organisms, they're going to die and that carbon is going to turn into methane, which is 23 times more powerful a greenhouse gas than CO2. There's also the matter of growing algae in tubes made of petroleum plastic. How much carbon went into mining & processing the petroleum, manufacturing your tubes, and transporting them out to where your facility is, 100 miles from the nearest Starbucks? How long will it take you to pay off that carbon debt? (If there's a biobased alternative I'd love to hear about it.) But there are solutions as well as problems. Aquaponic systems don't have to be directly coupled, for instance. And those biofilms are much denser than planktonic growth (ie tubes). My main "research" area (calling me a researcher would be too generous) is attached growth cultivation systems, for a lot of these same reasons. Pyrolysis can be used to turn the carbon into a biochar with very low bioavailability, solving the issue with methane. PS Just to clarify, bubbling doesn't maximize growth as much as keep the algae alive. Keeping high-density algae well mixed does ensure that everyone gets their turn to be in the sun. But algae can't survive in an anoxic environment, and without aeration a tall column of water will quickly become anoxic. The algae on the bottom will rot and you're back to converting CO2 into methane (which, in most systems, would come right out of the top of the tube). Additionally, aeration provides CO2; no CO2 would mean no photosynthesis.

mncolinlee 8y ago

Wouldn't it be likely that the greater than percentage of free CO2, the cheaper removing CO2 will get per ton? Trump's intransigence could make this technology viable.