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> All you need is napkin maths. We gain energy by turning carbon into carbon dioxide. Now, we need the same energy to reverse it, but with a loss factor. I'm o

by Tade0 2y ago

> All you need is napkin maths. We gain energy by turning carbon into carbon dioxide. Now, we need the same energy to reverse it, but with a loss factor. I'm of the opinion that no matter the level of cartoon villainy the oil industry is accused of - they're most likely guilty, but there's an inaccuracy here: In hydrocarbons the majority of energy comes from the oxidation of hydrogen. We should get rid of coal first, as it's irredeemable in this regard and methane second, as it's a greenhouse gas which tends to leak, but it's theoretically possible to burn hydrocarbons and turn the CO2 to coal and leave it like that with a net energy gain - it's just hugely impractical compared to not burning them in the first place.

aDyslecticCrow 2y ago
> In hydrocarbons the majority of energy comes from the oxidation of hydrogen. This I wasn't quite aware of. Thanks for the correction. > But it's theoretically possible to burn hydrocarbons and turn the CO2 into coal and leave it like that with a net energy gain This would be a game-changer! Though "theoretically" is pulling a bit of weight here... > We should get rid of coal first, as it's irredeemable in this regard and methane second, as it's a greenhouse gas which tends to leak, I also agree with your list. Burning stuff for grid energy should stop ASAP. Liquid fuel for transport is, however, the most difficult and probably the last to be replaced. It's to the point that generating green liquid fuels (that don't use fossil sources of carbon) is still actively researched and used, as air travel or shipping may never become feasible on green energy sources.
- bluGill 2y ago
  Ever see a diesel 'rolling coal'? They are burning the hydrogen and sending carbon into the air. Terrible for the local evironment though. this is still carbon positive though since some carbon is burned - just not all.
- blkhawk 2y ago
  > But it's theoretically possible to burn hydrocarbons and turn the CO2 into coal and leave > it like that with a net energy gain > This would be a game-changer! Though "theoretically" is pulling a bit of weight here... In nat. gas this is possible - its called pyrolisis - as an alternative to steam reformation it is generating pure carbon and hydrogen instead of the CO2 and Hydrogen that steam reformation does. Its main downside is that it takes more energy so you get less usable energy out of the process. You can do it with other organic fuels as well and the simplest process is making charcoal from wood but its not as clear a way to separate out carbon there.
- taurknaut 2y ago
  > Burning stuff for grid energy should stop ASAP. Sadly I think the only viable route to this is wealthy countries paying poor countries to dismantle these power plants (and presumably replace them with something equivalent). This has two nice benefits. One, wealthy countries show they act in good faith. Two, this will greatly reduce wealth disparity. Of course, there's the chance some people will threaten to emit gas to acquire disproportionate power. This is true, but still preferable to the west just roasting the planet and then blaming china. Like grow tf up.
  - amrocha 2y ago
    This is putting the cart before the horses. These wealthy countries haven’t even stopped burning fossil fuels. Let’s focus on that first.
    - taurknaut 2y ago
      Why not both? We've been claiming to want to reduce carbon emissions since before I was born. It's not even a hard pitch—if we're insanely wealthy and have the capacity to discuss greening our grid and still can't or won't, why would you reasonably expect countries with basically no capacity to do this to forget about centuries of globalization, colonization, and exploitation? We burned the globe; if we want to heal this, the most reasonable approach is good-faith reconciliation and remediation. But the way conversation is now we're headed straight towards ecofascism. A healthy globe for me but not for thee (as if this even makes much sense).
      - bruce511 2y ago
        You're right. It's convenient for the US to blame "developing economies" (especially China) for the problem. Solutions like "buying off other countries" make sense. (And in itself is not a bad idea.) But it's a deflection from the bigger issue which is consumption at home. But as long as we can make it a "them " problem, our population doesn't have to feel guilt, or understand they are the people who need to change.
      - nradov 2y ago
- tremon 2y ago
  shipping may never become feasible on green energy sources If only we had some historical records explaining how pre-industrialized societies navigated the globe without fossil fuels...
  - pfisch 2y ago
    Did those societies feed and clothe billions of people?
- xbmcuser 2y ago
  China has started adding battery electric container ships to it's local shipping fleets. They have also started using some battery electric cargo trains. Now if they can just get off coal for their electricity consumption they are very close to the tipping point. So in my opinion we are getting there in terms of carbon output but I also think it is to late to stop global warming and we have crossed the point of no return already. https://electrek.co/2024/05/02/fully-electric-10000-ton-container-ship-begun-service50000-kwh-batteries/ https://electrek.co/2024/05/02/fully-electric-10000-ton-cont...
  - bruce511 2y ago
    There's still a ways to go, but China are progressing faster at this than the US is. https://www.reuters.com/business/energy/chinas-solar-wind-power-installed-capacity-soars-2024-2025-01-21 https://www.reuters.com/business/energy/chinas-solar-wind-po... While the US looks at China as the convenient villan here, the rest of the world sees the US as the villan and China at least aggressively attacking the problem. And that's before we consider the impact Chinese exports of solar panels and inverters have had on renewable energy production outside of China. One may not like the system of govt in China, or their human rights policies (personally, I don't, but each to his own), but as far as climate change goes they're getting stuff done while the US govt does nothing. Or actively fights against improvements.
    - xbmcuser 2y ago
      China is demonized in the western countries for human rights abuses only because it is a communist country I am not saying that China is not doing bad shit but that western countries hypocrisy of only highlighting China. Where as they themselves have exploited and are still exploiting African countries resources by using corrupt African politicians that are doing many human rights on their people. At least Europeans have started to at least call-out Israel now but they should also call out US for enabling Israel but for those abuses it's okay not to say anything to the US.
      - nradov 2y ago
rob74 2y ago
Are you telling me that you're against good clean American coal?! https://www.theguardian.com/us-news/2025/feb/03/trump-war-on-clean-energy-big-oil https://www.theguardian.com/us-news/2025/feb/03/trump-war-on... (BTW I agree with you, but the current political climate - and not only in the US - seems to go in the entirely wrong direction)
pjc50 2y ago
There's a pretty insane scheme called "underground coal gasification" which had been proposed for the Firth of Forth. It's the same process as town gas - partial oxidation of coal to hydrogen and carbon monoxide. Bus in situ. So a controlled underground coal fire.
- thinkcontext 2y ago
  There's a similar idea to gasify old oil and gas wells. This sounds more feasible than doing it with coal though I suppose you could have a blowout. It should be cheaper too since it uses already drilled wells. https://protonh2.com/protonh2-advances-project-apollo-with-selection-of-epc-partner-and-completion-of-pre-feed-phase/ https://protonh2.com/protonh2-advances-project-apollo-with-s...
AnthonyMouse 2y ago
> it's theoretically possible to burn hydrocarbons and turn the CO2 to coal and leave it like that with a net energy gain - it's just hugely impractical compared to not burning them in the first place. It's also theoretically possible to have chemical reactions that bind carbon from the air into solid compounds that aren't themselves combustible without a net energy loss, but then you need a very large volume of reactants and produce a very large volume of industrial waste and it still turns out to be highly uneconomical compared to the cost of replacing fossil fuels for power generation.
- cyberax 2y ago
  > It's also theoretically possible to have chemical reactions that bind carbon from the air into solid compounds that aren't themselves combustible without a net energy loss That's not true. The reactants must have enough stored potential energy to reduce carbon. You might get that for "free" by using accelerated weathering of rocks (the energy ultimately comes from the radioactive decay in Earth's core).
  - AnthonyMouse 2y ago
    "Net energy loss" meaning you have to supply some energy in the form of heat or electricity to make the reaction go, and you don't get it back. There are things that will react with CO2 and form something that isn't combustible. That reaction may even generate heat that you could hypothetically use for something, but in practice probably not enough of it to be worth extracting.
    - cyberax 2y ago
      > There are things that will react with CO2 and form something that isn't combustible. Sure. There are plenty of such things. For example, elemental magnesium will happily bind carbon dioxide into pretty inert magnesium carbonate. But to _get_ that elemental magnesium, you need to expend energy, because elemental magnesium can't be found in nature. There is only one realistic option: rock weathering. Silicate rocks can react with carbon dioxide to produce calcium carbonate and (eventually) silicon dioxide.
rob_c 2y ago
> I'm of the opinion that no matter the level of cartoon villainy the oil industry is accused of - they're most likely guilty, Unfortunately their success over the years is showing others like the airline industry how to behave. There's some great "support" getting cloud into the extreme left (who are anti science like the extreme right) who conveniently love talking about chem trail style nonsense... Which is a shame because if we actually made an effort to reduce these clouds we'd make a big step forward to improving things for little effort... (Notice how I'm not saying fix, we're closer to fusion at scale than battery powered commercial flights I suspect)
- lazyasciiart 2y ago
  > There's some great "support" getting cloud into the extreme left Is this sentence missing a word or is it a use of the word “cloud” that I don’t know?
cyberax 2y ago
> In hydrocarbons the majority of energy comes from the oxidation of hydrogen. That's not quite true. To add some numbers, the average formula for long-chain hydrocarbons is roughly CH2 (one carbon atom for two hydrogen atoms). The enthalpy of formation of water is -286kJ/mole, and for carbon dioxide it's -394kJ/mole. Conveniently enough, one mole of long-chain hydrocarbons produces one mole of water and one mole of carbon dioxide. It's better for pure methane, as with its formula CH4 it produces 2 moles of water for each mole of CO2. So you get 572kJ of energy from hydrogens versus the same 394kJ from carbon.
- Tade0 2y ago
  Formation is just one part of the equation. On the other side there's an additional C-C bond per segment of the hydrocarbon chain longer than methane, which you need to break during combustion.
  - cyberax 2y ago
    It's already taken into the account. The CO2 enthalpy of formation has C-C bond breaking "baked in", by convention the "standard" form of an element has zero enthalpy of formation. For carbon, it's graphite with its C-C bonds. I did neglect the C-H bond enthalpy, but it's close enough to the C-C bond energy to matter too much.
deleted 2y ago
[deleted]

by Tade0 2y ago

aDyslecticCrow 2y ago

> In hydrocarbons the majority of energy comes from the oxidation of hydrogen. This I wasn't quite aware of. Thanks for the correction. > But it's theoretically possible to burn hydrocarbons and turn the CO2 into coal and leave it like that with a net energy gain This would be a game-changer! Though "theoretically" is pulling a bit of weight here... > We should get rid of coal first, as it's irredeemable in this regard and methane second, as it's a greenhouse gas which tends to leak, I also agree with your list. Burning stuff for grid energy should stop ASAP. Liquid fuel for transport is, however, the most difficult and probably the last to be replaced. It's to the point that generating green liquid fuels (that don't use fossil sources of carbon) is still actively researched and used, as air travel or shipping may never become feasible on green energy sources.

bluGill 2y ago
Ever see a diesel 'rolling coal'? They are burning the hydrogen and sending carbon into the air. Terrible for the local evironment though. this is still carbon positive though since some carbon is burned - just not all.
blkhawk 2y ago
> But it's theoretically possible to burn hydrocarbons and turn the CO2 into coal and leave > it like that with a net energy gain > This would be a game-changer! Though "theoretically" is pulling a bit of weight here... In nat. gas this is possible - its called pyrolisis - as an alternative to steam reformation it is generating pure carbon and hydrogen instead of the CO2 and Hydrogen that steam reformation does. Its main downside is that it takes more energy so you get less usable energy out of the process. You can do it with other organic fuels as well and the simplest process is making charcoal from wood but its not as clear a way to separate out carbon there.
taurknaut 2y ago
> Burning stuff for grid energy should stop ASAP. Sadly I think the only viable route to this is wealthy countries paying poor countries to dismantle these power plants (and presumably replace them with something equivalent). This has two nice benefits. One, wealthy countries show they act in good faith. Two, this will greatly reduce wealth disparity. Of course, there's the chance some people will threaten to emit gas to acquire disproportionate power. This is true, but still preferable to the west just roasting the planet and then blaming china. Like grow tf up.
- amrocha 2y ago
  This is putting the cart before the horses. These wealthy countries haven’t even stopped burning fossil fuels. Let’s focus on that first.
  - taurknaut 2y ago
    Why not both? We've been claiming to want to reduce carbon emissions since before I was born. It's not even a hard pitch—if we're insanely wealthy and have the capacity to discuss greening our grid and still can't or won't, why would you reasonably expect countries with basically no capacity to do this to forget about centuries of globalization, colonization, and exploitation? We burned the globe; if we want to heal this, the most reasonable approach is good-faith reconciliation and remediation. But the way conversation is now we're headed straight towards ecofascism. A healthy globe for me but not for thee (as if this even makes much sense).
    - bruce511 2y ago
      You're right. It's convenient for the US to blame "developing economies" (especially China) for the problem. Solutions like "buying off other countries" make sense. (And in itself is not a bad idea.) But it's a deflection from the bigger issue which is consumption at home. But as long as we can make it a "them " problem, our population doesn't have to feel guilt, or understand they are the people who need to change.
    - nradov 2y ago
tremon 2y ago
shipping may never become feasible on green energy sources If only we had some historical records explaining how pre-industrialized societies navigated the globe without fossil fuels...
- pfisch 2y ago
  Did those societies feed and clothe billions of people?
xbmcuser 2y ago
China has started adding battery electric container ships to it's local shipping fleets. They have also started using some battery electric cargo trains. Now if they can just get off coal for their electricity consumption they are very close to the tipping point. So in my opinion we are getting there in terms of carbon output but I also think it is to late to stop global warming and we have crossed the point of no return already. https://electrek.co/2024/05/02/fully-electric-10000-ton-container-ship-begun-service50000-kwh-batteries/ https://electrek.co/2024/05/02/fully-electric-10000-ton-cont...
- bruce511 2y ago
  There's still a ways to go, but China are progressing faster at this than the US is. https://www.reuters.com/business/energy/chinas-solar-wind-power-installed-capacity-soars-2024-2025-01-21 https://www.reuters.com/business/energy/chinas-solar-wind-po... While the US looks at China as the convenient villan here, the rest of the world sees the US as the villan and China at least aggressively attacking the problem. And that's before we consider the impact Chinese exports of solar panels and inverters have had on renewable energy production outside of China. One may not like the system of govt in China, or their human rights policies (personally, I don't, but each to his own), but as far as climate change goes they're getting stuff done while the US govt does nothing. Or actively fights against improvements.
  - xbmcuser 2y ago
    China is demonized in the western countries for human rights abuses only because it is a communist country I am not saying that China is not doing bad shit but that western countries hypocrisy of only highlighting China. Where as they themselves have exploited and are still exploiting African countries resources by using corrupt African politicians that are doing many human rights on their people. At least Europeans have started to at least call-out Israel now but they should also call out US for enabling Israel but for those abuses it's okay not to say anything to the US.
    - nradov 2y ago

rob74 2y ago

Are you telling me that you're against good clean American coal?! https://www.theguardian.com/us-news/2025/feb/03/trump-war-on-clean-energy-big-oil https://www.theguardian.com/us-news/2025/feb/03/trump-war-on... (BTW I agree with you, but the current political climate - and not only in the US - seems to go in the entirely wrong direction)

pjc50 2y ago

There's a pretty insane scheme called "underground coal gasification" which had been proposed for the Firth of Forth. It's the same process as town gas - partial oxidation of coal to hydrogen and carbon monoxide. Bus in situ. So a controlled underground coal fire.

thinkcontext 2y ago
There's a similar idea to gasify old oil and gas wells. This sounds more feasible than doing it with coal though I suppose you could have a blowout. It should be cheaper too since it uses already drilled wells. https://protonh2.com/protonh2-advances-project-apollo-with-selection-of-epc-partner-and-completion-of-pre-feed-phase/ https://protonh2.com/protonh2-advances-project-apollo-with-s...

AnthonyMouse 2y ago

> it's theoretically possible to burn hydrocarbons and turn the CO2 to coal and leave it like that with a net energy gain - it's just hugely impractical compared to not burning them in the first place. It's also theoretically possible to have chemical reactions that bind carbon from the air into solid compounds that aren't themselves combustible without a net energy loss, but then you need a very large volume of reactants and produce a very large volume of industrial waste and it still turns out to be highly uneconomical compared to the cost of replacing fossil fuels for power generation.

cyberax 2y ago
> It's also theoretically possible to have chemical reactions that bind carbon from the air into solid compounds that aren't themselves combustible without a net energy loss That's not true. The reactants must have enough stored potential energy to reduce carbon. You might get that for "free" by using accelerated weathering of rocks (the energy ultimately comes from the radioactive decay in Earth's core).
- AnthonyMouse 2y ago
  "Net energy loss" meaning you have to supply some energy in the form of heat or electricity to make the reaction go, and you don't get it back. There are things that will react with CO2 and form something that isn't combustible. That reaction may even generate heat that you could hypothetically use for something, but in practice probably not enough of it to be worth extracting.
  - cyberax 2y ago
    > There are things that will react with CO2 and form something that isn't combustible. Sure. There are plenty of such things. For example, elemental magnesium will happily bind carbon dioxide into pretty inert magnesium carbonate. But to _get_ that elemental magnesium, you need to expend energy, because elemental magnesium can't be found in nature. There is only one realistic option: rock weathering. Silicate rocks can react with carbon dioxide to produce calcium carbonate and (eventually) silicon dioxide.

rob_c 2y ago

> I'm of the opinion that no matter the level of cartoon villainy the oil industry is accused of - they're most likely guilty, Unfortunately their success over the years is showing others like the airline industry how to behave. There's some great "support" getting cloud into the extreme left (who are anti science like the extreme right) who conveniently love talking about chem trail style nonsense... Which is a shame because if we actually made an effort to reduce these clouds we'd make a big step forward to improving things for little effort... (Notice how I'm not saying fix, we're closer to fusion at scale than battery powered commercial flights I suspect)

lazyasciiart 2y ago
> There's some great "support" getting cloud into the extreme left Is this sentence missing a word or is it a use of the word “cloud” that I don’t know?

cyberax 2y ago

> In hydrocarbons the majority of energy comes from the oxidation of hydrogen. That's not quite true. To add some numbers, the average formula for long-chain hydrocarbons is roughly CH2 (one carbon atom for two hydrogen atoms). The enthalpy of formation of water is -286kJ/mole, and for carbon dioxide it's -394kJ/mole. Conveniently enough, one mole of long-chain hydrocarbons produces one mole of water and one mole of carbon dioxide. It's better for pure methane, as with its formula CH4 it produces 2 moles of water for each mole of CO2. So you get 572kJ of energy from hydrogens versus the same 394kJ from carbon.

Tade0 2y ago
Formation is just one part of the equation. On the other side there's an additional C-C bond per segment of the hydrocarbon chain longer than methane, which you need to break during combustion.
- cyberax 2y ago
  It's already taken into the account. The CO2 enthalpy of formation has C-C bond breaking "baked in", by convention the "standard" form of an element has zero enthalpy of formation. For carbon, it's graphite with its C-C bonds. I did neglect the C-H bond enthalpy, but it's close enough to the C-C bond energy to matter too much.

deleted 2y ago

[deleted]