New power source? CO2 in. Electricity and hydrogen out. - Page 2
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  1. #21
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    USA C02 emissions from coal is on the order of 4.3 Billion pounds of co2 from 1.18 billion tons of coal in 2008.... per year that is 3.7 tons per person.

    If you are getting the Na from NaCl then you have one Cl atom left over per c02 absorbed by the process we are discussing. Cl is 35, co2 is 44, so you will produce 3.5 billion tons of Cl in order to capture 4.4 billion tons of co2. which would produce 8.4 billion tons of sodium bicarbonate.


    The density of sodium bicarbonate is about twice that of coal, which means the next civilization will be very confused when they find all the prior coal mines filled up with baking soda.
    By volume it would be about a 1:1 ratio, 2 tons of baking soda for every ton of coal.

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    On the plus side, for get hydrogen oxygen rockets, you must be able to get to LEO with that much backing soda in the tank!


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    My post # 3 stands.

    Many thanks to jancollc and others on the chemistry, power levels, global market production levels of the associated materials, sodium and other stuff.

    So it seems the processes need to use (at least somewhat) large currents, high power, molten salts at high temperatures ..
    and then seems to be a net energy loss process, with probably large quantities of byproducts either not wanted or pretty much Very Not Wanted.

    As I said I *Like* the idea.
    But doubted if it has any realistic chance of working out in the real world as an actual industry.

    The process seems similar to making diesel/hydrocarbon fuels from air/seawater.
    - This is perfectly feasible and multiple pilot projects have proven it works.
    - But is is much cheaper and more energy efficient to make hydrocarbon fuels in other ways.

    Many such projects invoke things like "waste heat" from coal plants, or similar.
    Sure, extra heat occurs in coal plants, but also in alu smelters, foundries, nuke plants, etc.

    If a process only requires "waste heat" to be profitable it is likely nukes or foundries could be a much better implementation.

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    Quote Originally Posted by hanermo View Post
    My post # 3 stands.

    Many thanks to jancollc and others on the chemistry, power levels, global market production levels of the associated materials, sodium and other stuff.

    So it seems the processes need to use (at least somewhat) large currents, high power, molten salts at high temperatures ..
    and then seems to be a net energy loss process, with probably large quantities of byproducts either not wanted or pretty much Very Not Wanted.

    As I said I *Like* the idea.
    But doubted if it has any realistic chance of working out in the real world as an actual industry.

    The process seems similar to making diesel/hydrocarbon fuels from air/seawater.
    - This is perfectly feasible and multiple pilot projects have proven it works.
    - But is is much cheaper and more energy efficient to make hydrocarbon fuels in other ways.

    Many such projects invoke things like "waste heat" from coal plants, or similar.
    Sure, extra heat occurs in coal plants, but also in alu smelters, foundries, nuke plants, etc.

    If a process only requires "waste heat" to be profitable it is likely nukes or foundries could be a much better implementation.
    This gets back to what the real problem is which is one of entropy. No real solutions outside of addressing that.

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    Quote Originally Posted by johansen View Post
    USA C02 emissions from coal is on the order of 4.3 Billion pounds of co2 from 1.18 billion tons of coal in 2008.... per year that is 3.7 tons per person.

    If you are getting the Na from NaCl then you have one Cl atom left over per c02 absorbed by the process we are discussing. Cl is 35, co2 is 44, so you will produce 3.5 billion tons of Cl in order to capture 4.4 billion tons of co2. which would produce 8.4 billion tons of sodium bicarbonate.
    You are confusing me going from pounds to tons, you're obviously not going to produce more CO2 by weight than that amount of coal you burned....

    I meant to say 1.2 Billion tons of CO2 from coal. That is EIA data from 2017.

    How much of U.S. carbon dioxide emissions are associated with electricity generation? - FAQ - U.S. Energy Information Administration (EIA)

    Still much less that the 4.4 you cite, and since the process in the OP is 50% efficient, I am looking at a one-time through the hybrid cell scenario..

    That would mean removing 600 Million tons of CO2 annually. That would consume 313 million tons of Na (23/44*600), the production of which would also produce 476 million tons of Cl (23/35*313). The NaHCO3 produced would be 1.145 Billion tons, which is also a lot more than the current production of bicarb at ~4 million tons.

    That's way more Chlorine than the 65 million tons currently produced annually, so I will concede there is a chlorine problem.

    One potential way to deal with it would be to combine it with iron, which would be exothermic and produce ferric chloride. The heat could generate more electricity, but the waste ferric chloride would have to be disposed of.

    One way or another there would be a need to deal with the chlorine, so you were right about that.

    Maybe a simpler solution would just be to start with soda ash and just bubble CO2 through a solution:

    Na2CO3 + CO2 + H2O → 2NaHCO3

    The bicarb will precipitate out naturally.

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    Not sure why i made that mistake.

    Anyhow, 4.3 Billion tons of co2 is produced from 1.12 billion tons of coal burned.

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    Quote Originally Posted by johansen View Post
    ...Anyhow, 4.3 Billion tons of co2 is produced from 1.12 billion tons of coal burned.
    That makes no sense. Coal is not 100% carbon. So just taking the atomic weights of carbon and CO2 and multiplying by the tons of coal is not how to calculate the CO2 released. You have to account for the other combustion products too. Water, Coal ash, SO2, NOx...

    Simple combustion equation using methane for an example:

    CH₄ + 2O₂ → CO₂ + 2H₂O + HEAT

    1.744 Billion tons is how much CO2 was released from ALL fossil fuel power generation in 2017. Check the EIA link I posted.

    edit to add: Here is some more from the EIA
    The carbon dioxide emission factors in this article are expressed in terms of the energy content of coal as pounds of carbon dioxide per million Btu. Carbon dioxide (CO2) forms during coal combustion when one atom of carbon (C) unites with two atoms of oxygen (O) from the air. Because the atomic weight of carbon is 12 and that of oxygen is 16, the atomic weight of carbon dioxide is 44. Based on that ratio, and assuming complete combustion, 1 pound of carbon combines with 2.667 pounds of oxygen to produce 3.667 pounds of carbon dioxide. For example, coal with a carbon content of 78 percent and a heating value of 14,000 Btu per pound emits about 204.3 pounds of carbon dioxide per million Btu when completely burned.(5) Complete combustion of 1 short ton (2,000 pounds) of this coal will generate about 5,720 pounds (2.86 short tons) of carbon dioxide.
    Carbon Dioxide Emission Factors for Coal

    In 2017 the US consumed 716 Million short tons of coal, 93% of it was used for generating power.

    Annual Coal Report - Energy Information Administration

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    Think the other thing a lot of people miss here is you don't have to capture all CO2 to make a meaningful difference. if you could capture just 1/5th of current amounts you would buy a lot more time to address the CO2 issue.

    its like the notion that solar pannels don't work as you can generate all your electric that way at any time of day. All these things are part of a system, if we can change that to the better then its worth while, to make no change because its not a 100% fix is kinda dumb, when it comes to CO2 any helps surely?

    That said, i much prefer the bellow ground injection ideas, in the correct rocks its been shown to turn into various stone like states locking it away in a stable solid in under months and no reactive waste products like bicarb that are just sitting there waiting to break back down!

    Experiment 'turns waste CO2 to stone' - BBC News

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    Quote Originally Posted by jancollc View Post
    ....You are confusing me going from pounds to tons, you're obviously not going to produce more CO2 by weight than that amount of coal you burned....
    Geez, I'm getting punchy myself. I have to correct this statement, You obviously do produce more CO2 by weight. I was thinking in moles- doh!

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    so coincidentally the average co2 produced per person per year for the whole world is about the same 3.7 tons per year as does the USA produce just from burning coal alone.


    USA CO2 production per capita per year is about 20 tons. clearly, no one has room for 40 tons of baking soda per year in their backyard.

    This process of using sodium to make baking soda from c02 is of course interesting, perhaps more research into this will produce better sodium ion batteries. but as for offsetting the CO2 produced by any chemical industry.. there are a lot better things we can do with the energy that would have gone into producing the sodium, such as not burning the carbon in the first place.

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    Quote Originally Posted by johansen View Post
    there are a lot better things we can do with the energy that would have gone into producing the sodium, such as not burning the carbon in the first place.
    As a short-term palliative, how much could we save by banning leaf-blowers ?

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    Quote Originally Posted by EmanuelGoldstein View Post
    As a short-term palliative, how much could we save by banning leaf-blowers ?
    I’d ban those anyway.
    We have at least one neighbor who is up at 7am every Sunday.

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    One of the largest difficulties with industrialization of this sort of process is that you don’t get reagent grade reactants from burning fossils..the electrodes and electrolytes rapidly become poisoned.

    Then there the use of waste heat.
    There are different grades of heat, and just as a matter of economics large processes try to get as much use out of it as possible.

    Finally hydrogen is a shit fuel.
    It doesn’t compress and liquify nicely, it leaks away...it’s just a pain in the ass.

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    Yes, ... and no.

    Hydrogen is not a fuel, it is an energy storage medium like lead-acid 12V batteries in cars, or lion batteries, or natural gas, butane, propane, etc.

    Hydrogen is the most slippery smallest molecule gas, practically impossible to efficiently store past short term.
    It does hydrogen embrittlement in steels, and leaks past any seals and through any materials known.
    It leaks slowly-fast depending on the vessel, temp, pressure and stuff.

    E.
    Caverns keep air force diesel fuel at 4C cold temps, in granite, for decades.
    Nothing we know of can keep similar quantities of hydrogen for months to years, without some significant losses.

    Hydrogen is a potential good fuel for engines/fuel cells, if it was cheap. But it is not.
    It burns cleanly, if with somewhat low energy density, and does not necessary degrade the engine internals as much as diesel etc.

    But hydrogen takes 5x more energy to create the same result as a lion battery.
    Hydrogen is made by steaming crude oil. Hydrolysis iirc.

    An electric-only electrolysis process is more costly and slow, and much less efficient.
    = expensive.

    Hydrogen is very very hard to pipe, contain, compress, transport.
    It is quite dangerous, as it is a natural explosive in air.

    Once we get an abundance of energy from pv cells, it c/would potentially make sense to store peak power in hydrogen, if we could somehow soak it into something and store it.
    Today, we cannot.

    Quote Originally Posted by Miguels244 View Post
    Finally hydrogen is a shit fuel.
    It doesn’t compress and liquify nicely, it leaks away...it’s just a pain in the ass.

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    I really wish I understood chemistry better most of this is right over my head.

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    Disagree, politely.
    Entropy says you cannot dig up sand, filter it, and get gazillion joules (say 1MWh++) of energy per kg out of the refined sand.
    Yet nuclear reactors do this all the time.

    The *real* thing is, entropy actually accounts for potential energy (uranium) and stored energy (oil/gas).
    There are zero reasons in physics we cannot capture co2, or create energy from uranium, or from cold fusion (in theory).
    Or pump the energy back into another rock of some kind.
    Potentially.

    We just don´t know how to do cold fusion, or pump the energy back into rocks, etc. (Economically.)

    There is zero reason a process might not convert an input material into something else, while capturing the co2.
    The only criticism I had was cost, efficiency, reality today.

    I saw rocketry university books from 60s that proved, conclusively, that todays stepper and servo motors are impossible due to the magnetic flux densities being impossible.
    Before rare earth doped motors appeared.
    And todays igbts and sic-carb semiconductors.

    The proposed process may work, to some extent, and might perhaps be scaled and or developed into something useful, some day.
    But when they quote 50% efficiency without any data or numbers, the claims are usually universally bogus.

    Quote Originally Posted by Ziggy2 View Post
    This gets back to what the real problem is which is one of entropy.
    No real solutions outside of addressing that.

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    Quote Originally Posted by hanermo View Post
    Disagree, politely.
    Entropy says you cannot dig up sand, filter it, and get gazillion joules (say 1MWh++) of energy per kg out of the refined sand.
    Yet nuclear reactors do this all the time.

    The *real* thing is, entropy actually accounts for potential energy (uranium) and stored energy (oil/gas).
    There are zero reasons in physics we cannot capture co2, or create energy from uranium, or from cold fusion (in theory).
    Or pump the energy back into another rock of some kind.
    Potentially.

    We just don´t know how to do cold fusion, or pump the energy back into rocks, etc. (Economically.)

    There is zero reason a process might not convert an input material into something else, while capturing the co2.
    The only criticism I had was cost, efficiency, reality today.

    I saw rocketry university books from 60s that proved, conclusively, that todays stepper and servo motors are impossible due to the magnetic flux densities being impossible.
    Before rare earth doped motors appeared.
    And todays igbts and sic-carb semiconductors.

    The proposed process may work, to some extent, and might perhaps be scaled and or developed into something useful, some day.
    But when they quote 50% efficiency without any data or numbers, the claims are usually universally bogus.
    Because of entropy, every energy transformation we do will result in a transformational loose or inefficiency. This is why perpetual machine does not exist.

    Even with nuclear fission and fusion, you have an increase in entropy with the transformation of the energy from the conversion of matter into energy. There are no free lunches at the entropy counter. Everything comes with a cost of increased entropy.

    Localizing our frame of reference to just the planet Earth and allowing for outside energy sources, the Sun, photosynthesis does allow for a decrease in entropy, when of the few cases in which it happens chemically. But even in this example, the overall entropy of the whole Universe is increasing as this is going on.

    This is why all of these schemes breakdown when applied to reality. The concept of scrubbing CO2 from the atmosphere is nice, but to do it we need the raw Na in sufficient quantities with an energy penalty in the refining process of producing the pure Na for the reaction which will produce a pile of sodium bicarbonate in addition to the Cl from the Na production reaction. If you need the Cl and the sodium bicarbonate for raw materials, this might make sense. If you are going to use this reaction as purely a form of CO2 removal from the atmosphere, you will always ultimately be faced with the fact that it will require more energy to do the reaction then what you get out of it.

    You can't fight the laws of thermal dynamics and expect to win. Everything we see around us indicates that the Universe is continuously moving from a low entropy state to a higher entropy state. Yes there are small bubbles that might violate this on a microscopic scale but at the macro level, it is always a condition of increasing entropy.

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    Quote Originally Posted by Ziggy2 View Post
    ...If you are going to use this reaction as purely a form of CO2 removal from the atmosphere, you will always ultimately be faced with the fact that it will require more energy to do the reaction then what you get out of it.
    Yeah, ultimately that's where I come down on this too. It would be okay on a small scale, but only at the level where the chlorine and bicarb could be absorbed by the normal demands of the chemical industry.

    Creating 450 million tons of chlorine to get rid of 300 million tons of CO2 just makes no sense. The solution is worse than the problem...

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    Based on my perusal of numbers quoted above (including the $0.20/lb Na production, which is of dubious applicability due to being a near 30 year old figure), I estimated that you could... kinda break even doing this. The power generated, under theoretical max conditions (per post #17), would cost $.04/kWhr in elemental Na alone. It is potentially profitable if you have really high efficiency, low overhead, minimal labor costs, etc.

    Then you have the resultant outputs. More ionic Chlorine than anyone knows what to do with, literal Tons of baking soda that can never be used for anything (or else you have sequestered ZERO CO2 as it is a byproduct of nearly all uses of the stuff), and some H2 that needs to be used up immediately and locally due to storage and transportation shortcomings. That's if you get the CO2 waste product for free. That costs something to separate out from the exhaust stream of a power plant. I suppose you could get the government to force them to provide it for you for free, then we are all still paying for it, but it just doesn't show up on your ledger. Actually, it's a double-whammy because it would increase power generation costs, making your generated electricity worth more and look better by comparison.

    Cool technology? Sure. Useful at some scale? Maybe. Silver bullet? Unlikely.


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