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Startups Capture CO2 and Store It In Concrete 111

Posted by BeauHD from the gotta-start-somewhere dept.
A California startup using rocks to soak up carbon dioxide from the air has teamed up with a Canadian company to mineralize the gas in concrete, a technological tie-up that is a first and they say could provide a model for fighting climate change globally. Reuters reports: Heirloom Carbon Technologies delivered about 30 kg (66 lb) of CO2 collected from the air around its San Francisco Bay Area headquarters to neighboring Central Concrete, a Vulcan Materials' (VMC.N) subsidiary that on Wednesday incorporated the gas into new concrete. That's equivalent to tailpipe emissions of driving about 75 miles (120 km) in a car. The joint effort was the first time that carbon dioxide absorbed from the atmosphere using such Direct Air Capture (DAC) technology had been secured in concrete, where the CO2 will stay put for centuries, several scientists said.

Heirloom heats crushed limestone to release naturally absorbed CO2, then puts the CO2-starved rock on columns of huge trays, where they act like sponges, soaking up close to half their weight in the gas over three days. The rock is then heated to release the collected ambient carbon dioxide, and the cycle repeats. Canada's CarbonCure, the concrete technology company, mixes CO2 with concrete ingredients, turning it into a mineral that strengthens the concrete, cutting the need for cement -- the part of concrete with the biggest carbon footprint.
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Startups Capture CO2 and Store It In Concrete More

Startups Capture CO2 and Store It In Concrete

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  • I refuse to trust anyone named Shashank.

  • Bring back the dinosaurs (Score:4, Funny)

    by Flownez ( 589611 ) on Friday February 03, 2023 @09:26PM (#63264133)
    Why don't we breed dinosaurs en masse and then bury them? It's a proven technology.

    • ok starting with raptors

    • Re: (Score:2)

      by pz ( 113803 )

      Why don't we breed dinosaurs en masse and then bury them? It's a proven technology.

      You're obviously trying to be cute, but a serious approach would indeed to be plant a heapload more trees. The second part, cutting them down, pulverizing them, and putting the bricks of compressed chips into tapped-out coal mines is optional.

      And there's absolutely nothing stopping us from doing that along with sequestering CO2 in concrete as TFA suggests.

      • Concrete production is a CO2 intensive process already. The summary stinks, but the article isn't much better. They are using lime to "soak up" CO2 then heating it to release it. Then through some form of magic it gets put into the concrete, they ignore that detail entirely. They also don't explain what they've done to eliminate the CO2 release from the concrete production so how this ends up as a net negative CO2 contributer is unclear.

        • That got me too. I started thinking "This sounds a lot like quicklime mortar". Things will get interesting when engineers and chemists start asking questions.

        • Concrete naturally absorbs CO2 from the air. Concrete is alkaline, CO2 is acidic, they are going to get together. Hydrated calcium oxide reacts with CO2 to turn back into the limestone (calcium carbonate) from which it came. If they found a way to speed up the process then it's actually useful. Normally it takes decades, ambient temperature diffusion being quite slow.

          • There's a pretty "infamous" instance of this. Biosphere 2 failed to account for CO2 being absorbed by concrete and the inhabitants would have suffocated [dartmoutha...gazine.com] without supplemental oxygen.

          • to turn back into the limestone (calcium carbonate) from which it came.

            Aye, and there's the rub. Whatever the cement (diluted with rocks to make concrete) after you've made it doesn't equal, let alone exceed, the amount of CO2 emitted in the process of making the lime (quick, or hydrated) needed to make the cement minerals in the furnace.

            At best, processes like this can move CO2 absorption in time and place away from the point source of CO2 at the lime kiln. (Which is normally part of the cement-making p

        • Re: (Score:3)

          by nasch ( 598556 )

          They also don't explain what they've done to eliminate the CO2 release from the concrete production so how this ends up as a net negative CO2 contributer is unclear.

          If the concrete is going to be made either way, reducing the net amount of CO2 its production puts out is beneficial, even if it is still putting out some.

        • Depressing, isn't it, that the top half of the /. thread is buried in some political bullshit, and here's the first comment on the actual science of the proposal around the half-way point in the pile.

          You're right. There's a lot of interesting mineralogy in and around cement minerals, and there may indeed be ways to make cement production less CO2-intensive overall. But as it's currently practices, and in all alternative schemes I know of, turning rocks you dig out of the ground into cement (and then, by mi

      • plant a heapload more trees.

        There is no possible way to plant enough trees to make a significant difference.

        Planting trees is nice, but it is not a solution to global warming.

        along with sequestering CO2 in concrete as TFA suggests.

        Removing CO2 from the atmosphere is energy intensive. We burn fossil fuels to generate energy.

        The money spent on this silly sequestration-in-concrete scheme would do far more good if spent on solar panels and wind turbines.

        • Re: (Score:3)

          by Whibla ( 210729 )

          The money spent on this silly sequestration-in-concrete scheme would do far more good if spent on solar panels and wind turbines.

          For a rare change I'm going to disagree with you, slightly.

          While I agree that our productive focus should be on 'greening' our electricity supply, our research focus is not so clearly indicated. The amount of money being spent on this is relatively trivial, whereas the data gained will be invaluable in directing future production.

          Money spent on (decent) research, up to and including pilot plants, is rarely a waste.

    • Do that with algae and maybe you're on to something.

    • We are the dinosaurs today. We are going extinct, because we bread en masse , and overused all resources.

      • No, we're not. Chickens, turkeys and wild birds are the dinosaurs today.

        And we can use the stuff we "bread" to feed the chickens. Though it's better to use the stuff we "bred" (yes, those two words are pronounced the same way, but that doesn't mean they have the same meaning, so they're not interchangeable).

        All that aside, it's unlikely we're going to be extinct as a result of AGW - restricted to arctic and antarctic regions, perhaps.

        Though if we can't handle AGW, we're going to have a tough time when

      • Thank you for reminding me I need to go to the bakery later.

  • So someone rediscovered CO2 scrubbers of the sort used for diving, space ships, and other breathing applications? This doesn't really scale well. But I guess it requires less equipment than distilling liquified air.

  • "crushed limestone to release naturally absorbed CO2, then puts the CO2-starved rock on columns of huge trays, where they act like sponges, soaking up close to half their weight in the gas over three days. The rock is then heated to release the collected ambient carbon dioxide, and the cycle repeats" They capture CO2 gas and then release it back into the air. How does this mean "stores it in concrete"? I do not see that conclusion.

    • Re: (Score:2)

      by dynamo ( 6127 )

      Yeah, especially that first part where they "release naturally absorbed CO2" seems like a bit of a deal breaker as it sounds like they are releasing as much CO2 as they are storing in the process. If they talked about how to capture that CO2 released during the heating, that would be different, but this is just switching which CO2 is there, not putting in new CO2 in an empty container. And it seems like it's just left in the air. If the cycle repeats, does that mean the loop is so short that the collected a

      • The limestone (CaCO3) is baked once to release CO2 and create lime (CaO).

        After that, the lime can be used over and over. It isn't a one-shot process.

        Here is how it works:

        1. Dissolve lye (NaOH) in water.

        2. Expose the lye-water to the atmosphere. It absorbs CO2 to form sodium carbonate (Na2CO3).

        3. Dump lime (CaO) into the Na2CO3 solution to create CaCO3 and NaOH. Calcium carbonate then precipitates out of solution.

        4. Dry the CaCO3 with low-grade heat, then bake it to separate the CO2 and turn the calcium back

        • Think of the energy! Ultimately thermodynamics is a bitch.

        • The one big mistake is to use regular atmosphere for this. Instead, if they work with Diablo power plant, they heat the water for desalination, which drives out 30x the CO2 that atmosphere holds. This approach would allow them to speed things up, while using clean energy for rest of process.

    • Re:Somehow this does not explain (Score:5, Informative)

      by Jayhawk0123 ( 8440955 ) on Friday February 03, 2023 @10:30PM (#63264209)

      helps to read the full article...

      the limestone is used as a cheap, natural tool to temporarily capture CO2.

      The lime stone is heated to release CO2 which is then (per the effin article) "CarbonCure, the concrete technology company, mixes CO2 with concrete ingredients, turning it into a mineral that strengthens the concrete, cutting the need for cement — the part of concrete with the biggest carbon footprint."

      So the limestone acts as a natural, re-usable tool to absorb CO2, then put into a chamber, heated, and the released CO2 is mixed into concrete and the now CO2 empty limestone is used to absorb more CO2 from the air.

      heat, and repeat....

      As long as what they use to heat the limestone is clean, this could be great. Concrete is still going to be made/used without this tech... so if a side benefit can be to use it for carbon capture... why not?

      • Rock Chalk!

      • You can't just "mix CO2 into concrete". That's not how anything works. The question is, what reaction is occurring that uses CO2?

        • how are you 153816? i used to have respect for the low numbers.. used to indicate knowledge and I'd trust their responses more.

          according to google, that's one of the many ways this thing works... you know, adding CO2 to concrete... but I'm sure you already did a quick search before posting so as to not be completely ignorant. /s

          • how are you 153816?

            Well son, when a man and a website love each other very much, the man creates an account on that website, and I was ostensibly the 153,816th person to do so.

            i used to have respect for the low numbers.. used to indicate knowledge and I'd trust their responses more.

            Tell us you're a noob without telling us

            • nah, not a noob.. been reading the site for over a decade... finally created an account to comment on lazy dipshits that can't be bothered to use their brain before posting. ;)

              do better bud

      • The problem is that this smells an awful lot like someone wants to cash in on sweet sweet carbon credits and in the end it's a carnival trick that just moves the emissions somewhere else and only works out economically because the energy to do that costs less than the credits.

      • So Roman-era concrete, then?

      • Calcining CaC03 consume huge amounts of energy, unless that energy is produced cleanly this may be a net producer of C02.

    • It's two processes from two companies. The heating and soaking is done to concentrate CO2 gas. The collected gas is then sent off to be sequestered into concrete.

    • Re: (Score:3, Insightful)

      by Gavino ( 560149 )
      It needs to be as convoluted as possible with enough smoke and mirrors so that no-one truly understand it. Only then can gullible and clueless legislators pitch it to equally clueless and gullible voters, who will subsequently stumble around in a Brownian motion repeating the words "trust the SCIENCE!" in a haughty tone to anyone within audible range, believing it will somehow "save the planet". And they will feel good because it's all about "the feels", up until the point they are living out of a cardboard

      • It needs to be as convoluted as possible with enough smoke and mirrors so that no-one truly understand it.

        It is not convoluted and not hard to understand. Many people have done the same thing before. There is nothing new described in TFA.

        It even works. The problem is that it is not cost-effective compared to other carbon mitigation projects, such as installing solar panels and wind turbines.

        This is not something we should be doing when there are far better ways to address GW.

    • The crushed limestone is acting as a "cheap", "renewable" CO2 concentrator. There are numerous methods to scrub CO2 from a gas stream, but some are more efficient. Remember that CO2 is only at ~400ppm (0.04%), so directly removing it can be very slow or require extremely large scrubbers to reach the needed surface area. Crushed limestone provides this surface area as a solid. The deabsorption process would be completed in a closed environment that results in a very concentrated CO2 stream. As long as the he

      • Re: (Score:2)

        by olddoc ( 152678 )
        " As long as the heat required for this step was CO2 negative" The first thing I thought. I hope they aren't cranking up a coal fired electric plant to heat the limestone!

  • Key bit right here (Score:3, Funny)

    by RightwingNutjob ( 1302813 ) on Friday February 03, 2023 @10:58PM (#63264243)

    The rock is then heated...

    Three guesses where that heat comes from. And the first two don't count.

    I suppose I could rag on them for sequestering the co2 by cooking off the already sequestered co2 in the limestone, but that's just too easy. Let some greenhorn cut his teeth on that one...

  • Just plant trees and stop cutting down the Amazon
    • Stop cutting down the Amazon, yes.

      Just plant trees - much harder. Lots of badly conceived and badly implemented tree planting campaigns have actually destroyed carbon capturing grasslands, and dead forests.

      • Stop cutting down the Amazon, yes. Just plant trees - much harder. Lots of badly conceived and badly implemented tree planting campaigns have actually destroyed carbon capturing grasslands, and dead forests.

        This whole thinking things through thing seems to rarely happen.

      • Yes, it's the net increase from trees that is the important figure, not the absolute. Hence suggestions that we might need four times as many trees to offset in the steady state with current emissions. It's not likely to be possible to find the space in areas not deserts, high mountains, permafrost, not urban, nor crop land, or not special in other ways, for example river deltas.

  • ... this process generates.

  • They missed the obvious name for this product: Carbonite

  • Net? (Score:1)

    by jdege ( 88942 )

    Am I missing something?

    They drive the carbon out of rock, and then the rock absorbs carbon to get back into balance, and they think they've made a net change?

    • Am I missing something?

      Yes.

      They drive the carbon out of rock, and then the rock absorbs carbon to get back into balance, and they think they've made a net change?

      It is a cyclic process. The absorbed CO2 comes from the atmosphere. The CO2 that is baked out is collected and sequestered. The lime is reused over and over.

    • From what I can gather, the CO2 they get from limestone is used in concrete or whatever. The crushed limestone, that now no longer contains the captured CO2, is put out in the air to capture more CO2.

      It's still stupid. They may as well just get CO2 from ocean water, or from coal and gas power plants directly.

  • they RELEASE the carbon dioxide that was trapped in them naturally only to suck in the co2 we generated and put out into the air?????? ffs

  • It could be I'm just sleepy (Score:1)

    by Anonymous Coward

    The price of carbon also needs to fall. The U.S. government and industry broadly see $100-a-tonne carbon dioxide as a reasonable price for broad deployment. Heirloom charges around $1,000 now; Samala expects to be at $100 by the time his projects are soaking up millions of tons a year.

    Concrete itself is controversial: it is the most used building material in the world, and it accounts for about 8% of global emissions of carbon dioxide, including those of its main binding agent, cement. CarbonCure's most-used technology cuts that by about 5%, said CarbonCure CEO Rob Niven. The new one using wastewater could cut a further 5%-10%.

    They expect to start with a 900% price increase to concrete? I'm sure this'll catch on quick.

    "To remove a billion tons from the air we need in the order of mid-hundreds of billions of dollars," said Samala, who expects funders of solar, buildings, transmission towers and other infrastructure to finance carbon infrastructure, too.

    I'll just roll my eyes to bed then, good night sweet slashdot.

    • Re: (Score:2)

      by Entrope ( 68843 )

      ... and a billion tons of CO2 is roughly equal [lbl.gov] to 1/8 ppm of the atmosphere. Currently the atmosphere is roughly 420 ppm, and it was 280 ppm in 1750. We could get back to pre-industrial levels by repeating that $500-ish billion expenditure merely 1100 times!

  • Surely it would be easier, and mitigate the ocean acidification somewhat.
  • And steadily releases even more of it over time. Do better, guys.

  • This is going to be solved by technological solutions, not by hectoring people and creating a new climate religion. Love stuff like this.

  • Wait... so they made a component of concrete, cooked limestone, to capture the C02 which was released by the cooking process and then put it back into some concrete?! So 2x the energy, first to cook the limestone and second to separate and capture the cooked off CO2?! OK, I have seen some stupid capture technology, but this one has to be the dumbest. How about we find a substitute for the limestone in concreate instead that is ENERGY EFFICIENT!

  • ... or just pushing the problem off to a future generation ... or is this yet another scam enabled by the constant fear-mongering over climate change emergency/crisis?

    Also:
    - who/how is the success of this (or any) approach measured?
    - given the earth is a closed system, what is the impact of sequestering in the long term?

  • If only there were a device that captured CO2 and then made productive use of that carbon - like maybe making food. What a glorious invention that would be. I don't think I would ever see a more glorious invention than a _____.

  • To solve global warming, all we need to do is cut down all the trees and replace them with concrete. Yeah, that's the ticket.

  • Cold Ocean water contains 20-30x the CO2 that the atmosphere does. By working with nuclear power plants, esp those with desalination, they can obtain a great deal more CO2 with far less energy. Diablo power plant would likely be very happy to work with them.
  • The numbers don't make sense to me - 30kg of CO2 from 120km of driving? My car uses around 11L of gas per 100km (it might be better in the summer, but it's winter and I only drive in the city during winter). There's no way that it's producing 30kg of CO2 when I used less than 9kg of fuel.

    • The numbers don't make sense to me - 30kg of CO2 from 120km of driving? My car uses around 11L of gas per 100km (it might be better in the summer, but it's winter and I only drive in the city during winter). There's no way that it's producing 30kg of CO2 when I used less than 9kg of fuel.

      Did you also account for the weight of the oxygen you carry around in your oxygen tank? Or do you just get it out of the air for free like everyone else...

  • Someone should let Mr. Corleone know about this (Score:3)

    by Dave Emami ( 237460 ) on Saturday February 04, 2023 @05:03PM (#63265539) Homepage
    Seems like a good side business for the Mafia, since they already have expertise in concrete-based disposal methods.

  • I'm not a genius or a chemist, but it seems like - 75mi@25mpg = 3 gallons, at an average weight around 6lb/gal = 18lb. Does burning 18lb gasoline really release 66lb in CO2?

  • It's how the mob got rid of Jimmy Hoffa.
  • Limestone is the component of cement that absorbs the CO2. How are they getting a net CO2 reduction if all they're doing is taking it out of limestone and then putting it back in?

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