• Rivalarrival@lemmy.today
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    2 days ago

    And all of the aside, this doesn’t math even if it worked. It takes too much energy to pull CO2 out of the air

    They aren’t taking it out of the air. They are taking it out of smoke stacks. It’s far easier to pull it out of highly concentrated sources like smoke stacks than to try to pull it directly out of the atmosphere.

    we’d have to put up CO2 condensers on a percentage of earths surface…

    You’re describing biofuels. Vegetation “condenses” the CO2 out of the atmosphere, incorporating it into carbohydrates.

    Burning biofuels, we produce H2O and CO2 in the smoke stacks. Every pound of CO2 pulled from the smoke stack is a pound removed from the atmosphere.

    Any introduction of fossil fuels into the process defeats the purpose, but the underlying technology is theoretically feasible with biofuel carbon sources.

    • theneverfox@pawb.social
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      1 day ago

      The biofuel thing is just further nonsense.

      If you’re pulling CO2 out of the air, why in the world would you turn around and burn it???

      That makes zero sense. For one, biofuels require processing, which means they might even be carbon positive before you burn it, and again, the scale needed to produce it in meaningful quantities is totally impractical.

      And again, you can’t just pump CO2 in the well and put an acme sized plug on it. The structure of the rock is destroyed by the process, it’ll just leak out. We’d need an entirely new method to store it, which was never the plan here

      This whole scheme is a fever dream designed to continue burning fossil fuels while siphoning away money from actual green movements

      • Rivalarrival@lemmy.today
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        21 hours ago

        If you’re pulling CO2 out of the air, why in the world would you turn around and burn it???

        Because the CO2 we pull out of the air is not in a form that we can feasibly sequester. It’s padded with excessive hydrogen and oxygen into carbohydrate chains. When we burn that vegetation, we convert it to primarily to H2O, along with some CO2. Targeting the CO2 alone, we can sequester a lot more for the same energy and same volume.

        The structure of the rock is destroyed by the process, it’ll just leak out.

        That rock sequestered hydrocarbons from the biosphere for millions of years. It’s not destroyed by the process. We use comparable methods for the strategic petroleum reserve and the national helium reserve.

        This whole scheme is a fever dream designed to continue burning fossil fuels

        That may be true. And yet, when used with non-fossil fuel sources, it does, indeed, serve to remove CO2 from the atmosphere, rather than simply reducing the emission of CO2.

        • theneverfox@pawb.social
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          18 hours ago

          I get what you’re saying, it sounds very reasonable conceptually. But the problem is that this is a chain so riddled with weak links it’s infeasible

          You’re right about biofuel… Except that biofuel is already refined biomass. The water is already removed, usually to become as close to pure hydrocarbons as possible. That’s a far more efficient CO2 sink than pure CO2, because the oxygen component is in the atmosphere

          It’s insane to burn biofuels to lower atmospheric CO2.

          And as far as the process being non-destructive… This technology was developed to use pressured CO2 to break smaller pockets in the rock, it’s like using a pressure chamber to deflate foam. Except the rocks aren’t plastic until your get a whole lot deeper, and the amount of pressure means the whole well is being pressurized beyond a level it was ever at naturally

          Can a big cavity in the Earth store gasses? Sure. Can an oil well? Maybe… But so far, the answer is it leaks

          As for your last point… If you instead ask if we should cram biofuels in the ground? That’s a way better idea, there’s something to it. It’s not a solution, it doesn’t scale to the levels where we can keep using fossil fuels everywhere, but it would sequester C02 very effectively. Kind of like it was before we dug it up and burned it

          • Rivalarrival@lemmy.today
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            15 hours ago

            You’re right about biofuel… Except that biofuel is already refined biomass. The water is already removed, usually to become as close to pure hydrocarbons as possible.

            Hydrocarbons.

            Chains of hydrogen and carbon.

            Your comment demonstrates you’re not fully understanding the chemistry of the combustion. If you remove the “water” I am talking about, you wouldn’t have a hydrocarbon. You would have only carbon.

            The “water” I am talking about is the “hydro” part of the “hydrocarbon”. That “hydro” does not become CO2 when it burns. That “hydro” becomes H2O.

            When burning lighter hydrocarbons, the majority of the exhaust in the stack is actually water vapor rather than CO2. Putting that hydrogen into the ground, unburnt, provides no additional benefit over putting just the CO2 into the ground. It merely fills up the reservoir faster, and requires even more energy for the same amount of carbon sequestration. Burning that biomass, it is (theoretically) possible for the energy recovered (after powering sequestration operations) to be a net positive.

            Sequestering the unburned biofuel without recovering that energy, the operation must be a net negative.

            • theneverfox@pawb.social
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              13 hours ago

              Chains of hydrogen and carbon.

              Yes, hydrogen, the smaller possible molecule, and carbon, which is smaller and lighter then oxygen

              Hydrocsrbon chains are the most efficient way to store carbon, aside from something like graphite.

              Who cares what it becomes when you burn it? CO2 is obviously not the optimal carbon sink, even before you start considering things like long term stability

              • Rivalarrival@lemmy.today
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                12 hours ago

                Hydrocsrbon chains are the most efficient way to store carbo

                Volumetric efficiency is not the relevant metric. Energy efficiency is much more important. The process you describe requires far greater energy input to complete the sequestration.

                Furthermore, the physical properties are a problem. Biomass appropriate to this process is conveyed as a flammable, pelletized solid; CO2 is an inert fluid. One of these can be pumped via pipeline into empty subterranean reservoirs; the other cannot.

    • theneverfox@pawb.social
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      2 days ago

      Ok… Come on now, I know you’ve been propagandized, and propaganda works, but let’s think this through

      If you capture CO2 out of smokestacks, what have you done? You’ve slightly reduced emissions by going after the lowest hanging fruit possible

      Are we going to do that to every power plant? Is every containment effort going to work? Does that actually fix the problem?

      • Rivalarrival@lemmy.today
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        1 day ago

        Ok… Come on now, I know you’ve been propagandized, and propaganda works, but let’s think this through

        Please read what I wrote, not what you think I said.

        If you capture CO2 out of smokestacks, what have you done?

        It depends on where that carbon came from. If it came from petroleum or coal feedstocks, you’ve slightly reduced emissions. But, the carbon from biofuels originated from the atmosphere. Vegetation captured that CO2 directly from the atmosphere, and incorporated it into the biomass. Burning it converted the biomass into concentrated CO2 and H2O; we’re capturing the concentrated CO2 out of that stream.

        Again: this does not replace the need to suspend fossil fuels. But the specific process I described does, indeed, extract CO2 from the biosphere.

        If we plow the vegetation under, we are burying the hydrogen and excess oxygen as well as the carbon. Burning it, we release the hydrogen (as water), but still bury the carbon.