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I don't even know why this is a question. So, people burn hydrocarbons for energy. How do you expect to capture the carbon piece into a stable compound that can

• gspr 6y ago
  > So, people burn hydrocarbons for energy. How do you expect to capture the carbon piece into a stable compound that can be buried without expending more energy? Please draw this chemical reaction out, along with energy balances and how endothermic it is. If you read the article, you'd see: > Nowadays, Industrial production accounts for one-quarter of CO2 emissions from energy and industrial processes. With the demand for cement, steel and chemicals remaining strong to support a growing and increasingly urbanised global population, the future production of these materials will have to be more efficient and emit much less CO2 if governments want to meet their climate goals. In other words, this technology is not targeted at capturing carbon that is burned for energy.
  • contravariant 6y ago
    Well the images of power plants as well as statements like > Carbon capture, usage and storage (CCUS) refers to a chain of different technologies aimed at capturing waste carbon dioxide (CO2), usually from large point sources of pollution like power plants or > Another drawback of carbon capture, usage and storage, is the considerable amount of extra power it requires, which would increase the cost of electricity Do give the distinct impression that they're talking about the production of energy (since 'increasing the cost of electricity' would be a weird way to phrase a pure increase in demand). If it was purely talking about processes that also happen to release CO2 then it doesn't make sense to solely talk about carbon capture vs. renewable energy like this article does as that's not an alternative. Now carbon capture might still be necessary in a fossil fuel free world, but the article puts no real arguments forward why that would be the case.
    • gspr 6y ago
      I agree that the first quote is unfortunate. For the second quote, I struggle to understand your point. It seems entirely relevant to me.
      • contravariant 6y ago
        Having it increase the cost of electricity only makes sense if you see it as part of the electricity production process. Otherwise it just increases the energy demand of the process, this makes the process more expensive, not energy. Perhaps it could drive up energy prices if it ended up being an immensely profitable use of energy, but that doesn't seem to be the case.
• DanBC 6y ago
  > The idea that you could do this belies total ignorance of chemistry, fossil fuel genesis and the laws of thermodynamics. Life actually does a pretty good job of turning CO2 into dirt which gets buried Coal: about 350m years ago we didn't have trees because lignin had not evolved. Then we got lignin, and trees, and when trees died and fell they just stayed there because we didn't have fungus that could decompose them. Then (about 50m years later) fungus evolved that could decompose trees. All coal exists in that 300m to 350m old seam. Life takes CO2, turns it into carbon, which is then released when those plants die and decompose. Forests are a buffer, not a sink.
  • FrojoS 6y ago
    I had no idea. Where can I read more about this please?
    • DanBC 6y ago
      I used a simplification. Wikipedia has a bit more detail: https://en.wikipedia.org/wiki/Carboniferous#Rocks_and_coal https://en.wikipedia.org/wiki/Carboniferous#Rocks_and_coal
  • cesis 6y ago
    There's a different opinion on lignin decomposing fungi: Delayed fungal evolution did not cause the Paleozoic peak in coal production https://www.pnas.org/content/113/9/2442 https://www.pnas.org/content/113/9/2442
    • est31 6y ago
      Thanks for linking the paper! I've thought the same delay was the case, but seems my knowledge is outdated by 4 years :).
    • japanuspus 6y ago
      Interesting -- thanks for linking. It's a pity though - I really liked the delay explanation!
  • 6y ago
• iguy 6y ago
  > The idea that you could do this belies total ignorance of chemistry, fossil fuel genesis and the laws of thermodynamics. This was many people's reaction to hearing about carbon capture. And one that TFA does nothing to dispel. But I'm not sure that's the final word, it sounds like there may be reversible chemical reactions which can actually capture carbon in an energy-efficient way. One source: https://manifoldlearning.com/episode-040/#transcript https://manifoldlearning.com/episode-040/#transcript
• bryanlarsen 6y ago
  gspr's answer is the primary answer, but a secondary answer is that carbon capture can use a clean cheap power like solar to clean up after power that isn't clean but has other attributes that solar doesn't, like being portable and/or not bursty. There are predictions that within a decade the price of solar will have dropped so much that it's going to be cheaper to create hydrocarbons by synthesizing them using atmospheric CO2 than it will be to pull them from the ground.
  • goldsteinq 6y ago
    Solar power is anything but cheap. Solar panels are very expensive, short-lived and manufacturing them produces plenty of CO2 and other pollutants. Nuclear energy is the closest we have to "clean and cheap".
    • epistasis 6y ago
      This is precisely reversed. Even the IEA has finally agreed that solar photovoltaic is the cheapest energy in history: https://www.popularmechanics.com/science/a34372005/solar-cheapest-energy-ever/ https://www.popularmechanics.com/science/a34372005/solar-che... And this is from an agency that is notoriously pessimistic and wrong about solar, vastly overestimating costs of solar and underestimating future deployments. So when the IEA has declared solar cheap, one can be sure that there is zero data to support otherwise. Similarly, the IEA has been unreasonably bullish about the cost of nuclear, but still places it as one of the most expensive sources of energy. The data is not on your side, and I have to wonder why you came to believe the things that you are saying.
      • bryanlarsen 6y ago
        Perhaps even more importantly, the price of solar has been steadily declining at a faster rate than all other types, and it's been doing it for decades. One could argue that it will suddenly stop declining in price, but that seems as silly as betting against Moore's law in the 80's. Solar has reached price cutover, and installations are exploding so the manufacturing learning curve should really start to bite.
• dan-robertson 6y ago
  This argument basically relies on the assumption that it is at least as energy intensive to convert CO2 into something more solid than the energy you get from burning hydrocarbons to produce that CO2, but I think that assumption isn’t true. I can’t recall where I saw it and I’m not a chemistry expert but conservation of energy is a thing and there is more potential energy in hydrocarbons than in some simple inert solid molecules containing carbon (which have slightly more potential energy than the CO2 and water produced by combustion). If you can be reasonably efficient then it is possible to extract energy from hydrocarbons without releasing CO2 into the atmosphere. That said, I don’t think there are any sufficiently efficient industrial scale processes to do this.
  • contravariant 6y ago
    You're worrying about the wrong part of the equation, the main problem is going to be what you're going to do with the oxygen. There's a reason why so many things tend to react violently with pure oxygen, to the point that we have an entire vocabulary dedicated just to that one class of reactions.
    • dan-robertson 6y ago
      I’m replying to a commenter who claims that it is thermodynamically impossible to extract energy from fossil fuels while capturing the carbon (ie not releasing CO2 into the environment). Obviously some chemistry needs to happen but I claim it is possible to still get net energy out while somehow capturing the CO2. See this page: https://longitudinal.blog/co2-series-part-2-co2-removal/ https://longitudinal.blog/co2-series-part-2-co2-removal/ with the bit that starts “Note: Interestingly, this is all much less than the heat of combustion”
  • pfdietz 6y ago
    Well, when nature does CO2 sequestration, it IS energy positive. The overall reaction silicates + CO2 --> silica + carbonates is mildly exothermic. This is why most of the carbon on Earth is in rocks, not in the atmosphere.
• _Microft 6y ago
  I think the misconception stems from thinking that we could be net-positive energywise. We cannot. We can (and currently sort of have to) extract energy from fossil sources because our economy runs on hydrocarbons but we will need to expend more energy later to put the extra carbon back where it belongs. The energy we will expend for this in the future has to be renewable. We are basically borrowing from our future selves and will have to pay back the debt one day.
  • m4rtink 6y ago
    This is a good summary - and it might just work out. There is a trend in our energy sources being more powerful and more efficient over time. More efficient solar panels, biger and more flexible wind turbines, bigger and safer nuclear reactors. So paying the "energy dept" in the future might be much easier than going without the fosil energy sources right now.
    • renw0rp 6y ago
      The "borrowing" is not without some side effects which might be hard or impossible to revert in the future. It's like driving accelerating train without the breaks and hoping that someone builds tracks fast enough that we won't derail
      • TeMPOraL 6y ago
        Loss of biodiversity is one big thing. The species that went extinct due to us industrializing the planet, and the species that will go extinct due to climate change (even if brief and ultimately mitigated) will not come back. Sure, evolution keeps running its RNG and eventually new and interesting species will start showing up. But that doesn't replace the causal link that is lost. Today, the variety of organisms on our planet gives biologists a chance to understand how crucial mechanisms of life evolved. As we erase that history, we make biological sciences that much harder, and by extension, slow the progress of everything from medicine through biotech to chemistry and material sciences.
  • iguy 6y ago
• henearkr 6y ago
  It implies the use of noncarbon energy sources. For example, ClimeWorks uses geothermal energy for its CCS plant in Island. Other noncarbon energy sources are nuclear energies (fusion or fission), and the noncarbon renewables wind, solar, tidal...).
• klunger 6y ago
  > How do you expect to capture the carbon piece into a stable compound that can be buried without expending more energy? This is a bit of a strawman. No one is claiming that it will be somehow energy neutral or break thermodynamics. It will obviously require significantly more energy input, not to mention the money. But that doesn't make it impossible or even a bad idea, if the energy fueling the process is nuclear or renewable.
  • SCHiM 6y ago
    Well, you almost need to be claiming that. If you claim otherwise the energy requirements are truly stupendous. That doesn't event mention that the energy must be green by necessity. Another commenters on this site (can't find the link) put it like this: You'd have to drive every mile ever ridden on fossil fuels in reverse. Every single ICE in boats and planes too. All gas, coal and oil plants too. The energy requirements are incomprehensible, truly. We're having trouble going carbon neutral already, but this scheme requires we go neutral and _then some_.
    • bamboozled 6y ago
      We probably don’t need to capture all of the CO2 though ? We can combine carbon capture with other solutions for example reforestation ? I actually wonder if a time might come where global cooling (too quickly) could become an issue. I know that sounds crazy today but suppose we get very good at reducing emissions and CO2, maybe things will require time to adapt too a cooler world.
      • saalweachter 6y ago
        Eh, you can worry about global cooling as a hypothetical outcome -- for instance, there is a "snowball Earth" feedback loop with the albedo of ice sheets -- but from a geoengineering perspective releasing CO2 into the atmosphere isn't that hard, and we've still got more than half of the known oil in the world left.
      • yifanl 6y ago
        We have a very well known set of processes to fix the issue of too few emissions, so I'd doubt that'd ever be a concern.
• jofer 6y ago
  You're badly misunderstanding the process. With current CCS you're taking high concentration stream of CO2 from combustion and injecting it into deep subsurface waters that you know will remain isolated. (I'm a geologist - we're good at identifying those.) It's highly soluble in water at those conditions. Ideally it reacts with there and precipitates into other minerals, but it doesn't have to. It's safe in solution as well.
  • waynecochran 6y ago
    How do CCS actually capture carbon? The article doesn't explain the details.
    • jofer 6y ago
      There are multiple mechanisms. One of the most common is membrane separation, where C02 is selectively allowed to pass through in a relatively high-pressure, C02-rich source such as a literal smokestack. Others are vaguely analogous to the chemical C02 scrubbers you might find in a submarine or in spacecraft. At present, it's mostly from high density sources that are producing C02. Membrane separation has been around for quite awhile, and works well for that case. It's largely impractical for capturing C02 directly from the air, though. Direct air capture is the hard part. The "chemical scrubber" approach is being widely tested, but it's hard to make the whole thing carbon negative. It's a tractable problem, but not an easy one.
      • ActionPlankton 6y ago
        An interesting theoretical calculation is the rate of entropy production due simply to mixing of smokestack gasses (high partial pressure of CO2) with atmosphere (low partial pressure of CO2). In principle this is wasted exergy -- lots of it. One could imagine some combination of semipermeable membranes and turbines to extract power from the mixing process (your mention of membrane separation reminded me of this). To be clear this is sci-fi though at this point. (I do believe, however, that there exist methods to extract energy from the mixing of salt and fresh water.) Likewise, this same idea is a strong argument for capturing CO2 from smokestacks instead of from atmosphere: Fundamentally, it takes energy to undo mixing. And if you want to capture the CO2 eventually anyway, then better to just do that than invent a theoretical "heat engine" driven by the difference in CO2 partial pressure, to get energy that you'll just need to spend somewhere else later (and then some) to get the CO2 back out of atmosphere... ...Actually this phrase "heat engine" now makes me think that maybe this isn't even that hard (in theory) using cold temperatures and phase changes to make dry ice. If it's possible to efficiently cycle the gas through these large temperature swings at all, it must require some kind of heat exchangers and regeneration between stages... (Surely if this were realistic people would have figured out how to do it by now, but it's an interesting thought/design experiment in thermodynamics...)
• gonzo41 6y ago
  I agree with you. I've been thinking lately a bit about the scale of the problem we face. We essentially need to create enough carbon sinks that balance out all the oil and coal burned since the industrial revolution. Hopefully we do something with it all like build a giant coal brick pyramid. It's really handy the sun shines light on us for free. I sort of have this crazy idea of turning large parts of the center of Australia into rain forest by using solar power desalinization plants to pump fresh sea water inland. But alas. Australia has carry over credits from Kyoto. She'll be right. I'm going to reread all the Dune books in the holidays.
  • WildParser 6y ago
    Instead of coal. Wouldn't plastics be a better storage material? -> Lego pyramid
    • regularfry 6y ago
      The problem with plastics is that (from hazy memory) producing 1kg of plastic might involve the release of 7kg of gaseous CO2. For plastics that are already produced, yes, that carbon's not going anywhere. Producing more plastic to sequester it would somewhat miss the point. Although a LEGO pyramid would be an amazing archaeological find to leave for future generations.
      • WildParser 6y ago
        It would be interesting to see the numbers for bioplastics like PLA. Growing starch-crops without fertilizers is probably the hard part. With these kind of bricks it would at least not be so difficult to motivate people to find appropriate storage facilities.
  • bamboozled 6y ago
    Australia shifts away from climate credit cheating. https://phys.org/news/2020-11-australia-shift-climate-credit.html https://phys.org/news/2020-11-australia-shift-climate-credit...
• JackeJR 6y ago
  Assuming that we WILL expend more energy to capture the carbon, the path to make carbon capture viable is clear: A source of energy that does not add more carbon to the atmosphere. And existing technologies such as nuclear fission already offers us abundance of energy to do this. The problem is one of scale (how widespread?), acceptability (where can we do this?), cost (who pays?) and time (how soon?).
• rayiner 6y ago
  The point of carbon capture isn’t to be energy neutral. The point is to be able to take clean energy (say nuclear energy in the United States) and capture carbon from dirty uses (say construction in India). Carbon capture will have to work because there will be no way to address climate change otherwise. Countries like India and everyone on the continent of Africa will industrialize, they will build vast structures out of concrete and they’ll use cheaper gas power cars and whatever energy they can get their hands on. My home country of Bangladesh will add a 80-100 million people and it’s GDP will increase by a factor of 5 by 2050. The idea that Bangladesh will jeopardize a single percentage point of GDP growth to make that growth carbon neutral as it rushes to bring middle income standards of living to its people is utterly absurd. The country’s CO2 emissions per capita has increased by a factor of five since I was born and it can increase by another factor of 10 before getting to the level of an efficient developed country like France. To compensate for massive CO2 output in those countries, developed countries will have to go carbon negative and capture that CO2. It’s so obvious I’m not sure how so many people overlook it.
  • bluGill 6y ago
    Surely the people of Africa or Bangladesh are not so stupid as to not learn lessons from the US. We have better technology now, so they will use that in a lot of cases. Don't get me wrong, there are cases where the old way is better because it is cheaper and so they will use that. However they won't use gas cars since we are developing battery cars, solar panels, and the like. Within a few years electric cars will be better for them as well.
    • rayiner 6y ago
      It’s not a matter of “stupidity,” but the desire for a better life. A “do nothing” climate change scenario will be bad for Bangladesh, but not as bad as hampering economic growth. By 2060, it will cost Bangladesh a third of its GDP. But put differently, losing a single percentage point of annual GDP growth over that period will be just as bad as the impact from climate change. New technology will be adopted, but not fast enough. Bangladesh is currently at 4% renewables. But half the country doesn’t even have electricity. It’s building 10 GW of coal capacity by 2030 which will double per capita CO2 output. Gas is still the major energy source with some nuclear being built. There is nowhere to build solar or windmills, though off shore wind is a possibility in the long term. It will be many decades before Bangladesh uses primarily electric vehicles and vast numbers of ICE vehicles will be purchased in the meantime. The number of registered motor vehicles has tripled in the last decade—those are nearly all gas vehicles, and half are used vehicles imported from elsewhere. 80% are motorcycles, with very inefficient gas engines. And there are no alternatives to CO2-production for many construction and industrial processes. Bangladesh will certainly take some measures to be greener. It has no economic incentive to use more fossil fuels than it needs to: it imports gas and coal and has no domestic industry or jobs in that area to protect. But it also can’t afford to subsidize renewables. It will deploy technologies based on true cost, and right now the cost of renewables + storage isn’t there, neither is the domestic infrastructure to go fully electric.
• Someone 6y ago
  The process need not be as efficient as nature; if it ‘only’ is both a net win and deployable at a scale that’s larger than we can do by planting trees/stopping cutting down trees, it could be a good idea, even if we get the energy needed for capturing CO2 from burning even more oil. And no, it need not belie the laws of thermodynamics. The idea isn’t to convert CO2 back to oil or do so without putting in more energy than burning oil gave us. In fact, some capture approaches keep the CO2 as CO2, for example by pumping it into empty oil fields (that makes me think “what could possibly go wrong?”, but hey, what do I know?) (I have trouble envisioning carbon capture to be a net win and feasible at scale, but I’m not an expert; it might work, just as burning forests to prevent forest fires from spreading has its uses)
• graeme 6y ago
  Yes, it will take a lot more energy. Burning carbon today is effectively civilizational credit card debt. We are prosperous but have a big compounding headache on the horizon. It may well be impossible to extract excess co2 from the atmosphere at scale. But if it is we are in very very serious trouble.
• blkknightarms 6y ago
  It's called sunlight and biological processes.
• tim333 6y ago
  Gas comes out of a hole in the ground, you burn it, stick the CO2 back into a different hole in the ground eg. https://www.bbc.com/news/uk-scotland-edinburgh-east-fife-49277556 https://www.bbc.com/news/uk-scotland-edinburgh-east-fife-492...
• philipkglass 6y ago
  The reaction between carbon dioxide and alkaline earth silicates is thermodynamically spontaneous in the presence of water, but kinetically hindered. It's a reaction with slow diffusion of reactants through the product layer, limited by surface area. So crush rocks rich in alkaline earth silicates and distribute them in near-shore environments. It's an artificially accelerated version of the geological carbon cycle. It still requires vast-in-absolute-terms amounts of energy to crush billions of tons of rock, but it's not running uphill against thermodynamics. Olivine: Mg2SiO4 + 2CO2 → 2MgCO3 + SiO2: ΔH -89 kJ mol/CO2 Serpentine: Mg3Si2O5(OH)4 + 3 CO2 → 3MgCO3 + 2SiO2 + 2H2O: ΔH -64 kJ mol/CO2 Wollastonite: CaSiO3 + CO2 → CaCO3 + SiO2: ΔH -90 kJ mol/CO2 https://www.ipcc.ch/site/assets/uploads/2018/03/srccs_chapter7-1.pdf https://www.ipcc.ch/site/assets/uploads/2018/03/srccs_chapte... (Section 7.2.2 "Chemistry of mineral carbonation")
  • CyanBird 6y ago
    We already have catalytic convertors on cars, can we add co2 capture to them as well? Add a little box with powdered olivine and some extra chemical bits to capture a higher % of co2 than absolute 0? Catalytic convertors already use finely coated incredibly expensive platinum to break down complex molecules, and it is certainly easier to capture co2 near the source than when dissipated in the atmosphere
    • dodobirdlord 6y ago
      No. The reaction happens in water, it’s fairly slow, the mixture needs to be agitated, and it would require similar quantities of silicates to the among of hydrocarbons being burned. Better to ignore capture at the source and instead prioritize mass-capture in places that are energy efficient. Shallow coastal areas near major deposits.
  • sunstone 6y ago
    A couple of H-bombs in the Himalayas might do the trick quite quickly.