Can ultracapacitors be used to split CO2 into carbon and oxygen?

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Discussion Overview

The discussion revolves around the feasibility of using ultracapacitors to split carbon dioxide (CO2) into carbon and oxygen. Participants explore the energy requirements for this process, the methods of achieving it, and the implications of their calculations. The conversation includes theoretical considerations, potential experimental setups, and challenges associated with the proposed methods.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant calculates the energy required to split CO2 and expresses confusion over the resulting temperature estimates, questioning the validity of their method.
  • Another participant provides a calculation for the energy required per molecule of CO2 and suggests that high temperatures are necessary to break the bonds, indicating that using an electric field from capacitor plates may not be effective due to the neutral nature of CO2.
  • A different participant proposes that pressurizing CO2 and adding an electrolyte might enable the splitting of CO2 into its components, raising a potential alternative approach.
  • Further clarification is sought regarding the temperature calculated for splitting CO2 and the reasoning behind the initial method's flaws.
  • Another participant reiterates the stability of CO2 and mentions photosynthesis as a natural process for producing oxygen from CO2, while noting that artificial attempts to replicate this have not been successful on a large scale.

Areas of Agreement / Disagreement

Participants express differing views on the methods and feasibility of splitting CO2, with no consensus reached on the effectiveness of ultracapacitors or the proposed alternative methods. The discussion remains unresolved regarding the best approach to achieve the splitting of CO2.

Contextual Notes

Participants highlight uncertainties in the calculations and assumptions made regarding energy requirements and methods. There is an acknowledgment of the complexity and stability of the CO2 molecule, as well as the limitations of the proposed techniques.

Who May Find This Useful

This discussion may be of interest to those researching carbon capture technologies, energy storage solutions, or chemical processes related to CO2 conversion.

PlanetGazer8350
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I have been researching on the bonding energies of different compounds, and for example, for CO2 it is 1600kJ/mole, 1600kJ/44g, or ~36.37kJ/g of energy required to split the carbon dioxide into carbon and oxygen. Furthermore, I transformed the amount of energy required in kJ to degrees celsius, and got 845.2 Cº for splitting 44g (or 1 mole), or 19.15 Cº for splitting 1 gram of CO2. However, the latter figure, as you may have noticed, is clearly absurd, as you logically cannot split 1 gram of CO2 with such a relatively low temperature.

I clearly understand that I am following the wrong procedure, although it seems the logical one at first, until, of course you arrive at an unreasonable figure. How should I find the required temperature for splitting a certain quantity of a compound? Also, why is my procedure wrong, and what have I not understood correctly?

Finally, I have also considered using a set of ultracapacitors connected together as an option to splitting CO2, (already having considered the amount of ultracapacitors needed): for example, to achieve an energy of ~36.37kJ (to split 1 gram of CO2) I would need 20 ultracapacitors with (individually) a voltage of 2.7V and capacitance of 500 farads. Would it be possible to split CO2 using ultracapacitors, or is this procedure also wrong, and why?

Thanks in advance
 
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1600 kJ/mole is ## 1.6 \cdot 10^6 \,J/(6.02 \cdot 10^{23})= 2.7 \cdot 10^{-18} \, J/ ##molecule. This will only be approximate, but with ## k_B=1.38 \cdot 10^{-23} \, J/K ##, the temperature ## T \approx 2 \cdot 10^5 ## to separate the ## CO_2 ## molecule into atoms by thermal means. ## \\ ## And putting the molecule into a strong electric field, such as between capacitor plates is not likely to separate it into components. The ## CO_2## molecule is electrically neutral and only slightly polar. It would not be affected appreciably by the voltage from two capacitor plates.
 
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However, if the CO2 was pressurized and turned into liquid, adding an electrolyte, would it be possible to split the CO2 into its components?

Edit: is the temperature (T): 2·105 the temperature required to split 1 molecule of CO2, in degrees kelvin? In addition, I now understand that your procedure is the correct one, but why exactly is my procedure wrong, (1600kJ/44g to get energy for 1 gram and then transform ~36.37kJ to celsius: 19.15 cº (which I know is wrong)), as it seems the most logical & proper one at first hand, and how to avoid these type of procedures on other concepts?
 
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The calculation shows energy ## E=2.7 \cdot 10^{-18} ## Joules/molecule. At a temperature of ## T=200,000 \, K ##, thermal energy will break most of the bonds in these molecules. That is only an approximate calculation, and each of the bond energies will actually be 1/2 of what I used above. This is only approximate, but it basically says that ## CO_2 ## is a very stable molecule. One way of getting ## O_2 ## in a process with ## CO_2 ## is by photosynthesis: ## CO_2+H_2 O \rightarrow CH_2O+O_2 ##. There have recently been attempts to do this process artificially, but it hasn't yet been achieved on a large scale. See e.g. https://www.physicsforums.com/threads/breaking-down-carbon-dioxide.916913/#post-5778727
 

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