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>If the CO2 emitted from the battery's materials came from the atmosphere in the first place, this will be a closed cycle and won't increase global CO2 levels.

>If the CO2 emitted from the battery's materials came from the atmosphere in the first place, this will be a closed cycle and won't increase global CO2 levels. The carbon emissions of aluminum smelting come from the carbon electrodes in the electrolytic cell-- you're essentially burning them to pull the oxygen atoms off the aluminum oxide molecule. http://en.wikipedia.org/wiki/Aluminium_smelting http://en.wikipedia.org/wiki/Aluminium_smelting Carbon electrodes used in industrial processes are generally formed from processed coal and mineral graphite: the fossiliest of the fossil fuels. You could theoretically produce synthetic bulk carbon from atmospheric CO2 using the Bosch process, (http://en.wikipedia.org/wiki/Bosch_reaction http://en.wikipedia.org/wiki/Bosch_reaction) at incredible cost per kilogram of carbon produced, which would then directly increase the cost per kilogram of aluminum smelted.

stcredzero 12y ago
Carbon electrodes used in industrial processes are generally formed from processed coal and mineral graphite: the fossiliest of the fossil fuels. Again, there's no fundamental reason why this must be the case. You could theoretically produce synthetic bulk carbon from atmospheric CO2 using the Bosch process, (http://en.wikipedia.org/wiki/Bosch_reaction http://en.wikipedia.org/wiki/Bosch_reaction) at incredible cost per kilogram of carbon produced, which would then directly increase the cost per kilogram of aluminum smelted. Yes, but this is like saying that because our present economic/industrial configuration is the way it is, there's no escape from emitting carbon, which is simply circular logic. Or, maybe you do understand the implication, which is that the only way out is for us to make energy much cheaper across the board.
- dojomouse 12y ago
  It's more like saying 'if you're looking at a new solution you better account for every step of the process, including costs and losses, and compare to viable alternatives, before deciding it's a good thing. The logic isn't circular. Rather, you're conflating multiple independent processes. Even if we did have a commercially viable way to capture atmospheric co2 and turn it back into carbon that still doesn't mean we should then burn the carbon to make batteries. We could also bury it, and use normal rechargeable batteries.
  - stcredzero 12y ago
    It's more like saying 'if you're looking at a new solution you better account for every step of the process...The logic isn't circular. In the general context of whether we can get ourselves out of carbon dioxide pollution, it is, and this happens again and again. If we assume that the current truism of our industrial society -- that you almost can't do anything without a carbon footprint -- is somehow true for all time is a vastly convoluted circular logic. You will also note that the "two positions" above are actually the same position. The big caveat is the massive power use in recycling. We just interpret that in two different ways. "Not viable because it's not viable in our present economic infrastructure" is a position that's clearly false in the historical record. Unless you're being specific to the short term only, using that to justify a position is just obfuscated circular logic.
    - dojomouse 12y ago
      Uhh... I disagree. Firstly, I don't see the circle in the following: - SolutionX puts lots of CO2 into the atmosphere compared to alternatives, and would be extremely uneconomic if we included in the cost/unitSolutionX the cost required to extract that CO2 from the atmosphere again. - Lots of CO2 in the atmosphere is bad -> SolutionX is either bad because it's uneconomic, or bad because it leads to lots of CO2 in the atmosphere. -> We shouldn't use SolutionX until some factors change such that SolutionX is better than alternatives, rather than worse. That's linear reasoning. If you want to change one of the underlying assumptions, namely that it's expensive to capture CO2 (and convert it back to carbon in this case... where at least the CO2 is coming from a concentrated point which reduces the cost of the process) then it's still linear reasoning with a slightly different result. For it to become circular there would have to be some step where we said "If we had SolutionX it would be cheap and easy to get CO2 from the atmosphere and turn it back into carbon, but we don't have SolutionX because the methods of getting CO2 from the atmosphere without SolutionX are expensive so SolutionX is dirty". That, interestingly, was used and is used as an argument against solar cells (e.g. solar cells made on power grids consume energy that may have a large CO2 loading). But it's easily revealed as bullshit through the use of EROEI (Energy returned on energy invested) accounting, and it's easy to show how 'SolutionX' (solar in this case) makes itself clean over time. How is that the case with this aluminium fuel cell concept? Any advances in energy generation and CO2 capture are probably going to happen independently of aluminium fuel cell production. There's certainly plenty of incentive for both already, the aluminium fuel cells won't create a new market. In conclusion, you're right that an aluminium based energy storage cycle would be more attractive if we had vast quantities of cheap and clean energy and low emission method of capturing CO2 and turning it into carbon. But.... 1. We have neither of those things 2. So for now an aluminium energy storage cycle is probably unattractive for most applications 3. If we did have both of those things it would totally change the economics of all sorts of other solutions, so you'd need to recalculate those as well before doing any comparisons between aluminium fuel cells and (e.g.) synthetic gasoline.

stcredzero 12y ago

Carbon electrodes used in industrial processes are generally formed from processed coal and mineral graphite: the fossiliest of the fossil fuels. Again, there's no fundamental reason why this must be the case. You could theoretically produce synthetic bulk carbon from atmospheric CO2 using the Bosch process, (http://en.wikipedia.org/wiki/Bosch_reaction http://en.wikipedia.org/wiki/Bosch_reaction) at incredible cost per kilogram of carbon produced, which would then directly increase the cost per kilogram of aluminum smelted. Yes, but this is like saying that because our present economic/industrial configuration is the way it is, there's no escape from emitting carbon, which is simply circular logic. Or, maybe you do understand the implication, which is that the only way out is for us to make energy much cheaper across the board.

dojomouse 12y ago
It's more like saying 'if you're looking at a new solution you better account for every step of the process, including costs and losses, and compare to viable alternatives, before deciding it's a good thing. The logic isn't circular. Rather, you're conflating multiple independent processes. Even if we did have a commercially viable way to capture atmospheric co2 and turn it back into carbon that still doesn't mean we should then burn the carbon to make batteries. We could also bury it, and use normal rechargeable batteries.
- stcredzero 12y ago
  It's more like saying 'if you're looking at a new solution you better account for every step of the process...The logic isn't circular. In the general context of whether we can get ourselves out of carbon dioxide pollution, it is, and this happens again and again. If we assume that the current truism of our industrial society -- that you almost can't do anything without a carbon footprint -- is somehow true for all time is a vastly convoluted circular logic. You will also note that the "two positions" above are actually the same position. The big caveat is the massive power use in recycling. We just interpret that in two different ways. "Not viable because it's not viable in our present economic infrastructure" is a position that's clearly false in the historical record. Unless you're being specific to the short term only, using that to justify a position is just obfuscated circular logic.
  - dojomouse 12y ago
    Uhh... I disagree. Firstly, I don't see the circle in the following: - SolutionX puts lots of CO2 into the atmosphere compared to alternatives, and would be extremely uneconomic if we included in the cost/unitSolutionX the cost required to extract that CO2 from the atmosphere again. - Lots of CO2 in the atmosphere is bad -> SolutionX is either bad because it's uneconomic, or bad because it leads to lots of CO2 in the atmosphere. -> We shouldn't use SolutionX until some factors change such that SolutionX is better than alternatives, rather than worse. That's linear reasoning. If you want to change one of the underlying assumptions, namely that it's expensive to capture CO2 (and convert it back to carbon in this case... where at least the CO2 is coming from a concentrated point which reduces the cost of the process) then it's still linear reasoning with a slightly different result. For it to become circular there would have to be some step where we said "If we had SolutionX it would be cheap and easy to get CO2 from the atmosphere and turn it back into carbon, but we don't have SolutionX because the methods of getting CO2 from the atmosphere without SolutionX are expensive so SolutionX is dirty". That, interestingly, was used and is used as an argument against solar cells (e.g. solar cells made on power grids consume energy that may have a large CO2 loading). But it's easily revealed as bullshit through the use of EROEI (Energy returned on energy invested) accounting, and it's easy to show how 'SolutionX' (solar in this case) makes itself clean over time. How is that the case with this aluminium fuel cell concept? Any advances in energy generation and CO2 capture are probably going to happen independently of aluminium fuel cell production. There's certainly plenty of incentive for both already, the aluminium fuel cells won't create a new market. In conclusion, you're right that an aluminium based energy storage cycle would be more attractive if we had vast quantities of cheap and clean energy and low emission method of capturing CO2 and turning it into carbon. But.... 1. We have neither of those things 2. So for now an aluminium energy storage cycle is probably unattractive for most applications 3. If we did have both of those things it would totally change the economics of all sorts of other solutions, so you'd need to recalculate those as well before doing any comparisons between aluminium fuel cells and (e.g.) synthetic gasoline.