[X-18]

Hello:

I'm trying to figure out how to separate the carbon from the oxygen in CO₂. Even if it has to be done in a process. Example, could one cause the oxygen to bond to a metal to create, say, Na₂O? All I need is simple decomposition.


Also, what kind of alcohol would a car run best on? Does anyone know of a list that has alcohols, how volitiale it is, and the energy stored in one mol?

Sorry, I know I'm very vague on both, my dad is leaving for town so I don't have anymore time but I'll try and come up with more of my own ideas when I get home. I've only been toying this around in my head for the last 2 days so... Any help is greatly appreciated.

X-18

[J.I.]

separate carbon from oxygen in carbon dioxide? try studying the process of photosynthesis.

[desperad0oo7]

This does not occur in photosynthesis. What happens in photosynthesis is that CO2 gets reduced to sugars without the seperation of the bonds. Oxygen that rise from plants is due to the photolysis of water by excited electrons from chlorophyl to 4 protons and O2.

am not sure about the original question though, but would imagine it to be very dificult. try and check if raney nickel coul reduce it to dihydroxymethane which could be broken off later, just a very rough Idea and most probably would not work, but who know

[mir]

Why not make a carboxylic acid in some way, from the CO2. Then reduce the acid to an alcohol. Then remove the alcohol through the tossylate.

Instead of doing the reduction, you might make the acid chloride with SOCl2. Then Let it react under nitrogen/argon with N-hydroxy-pyridin-2-tione to make the thiohydroxamic ester. Then initiate a radical reaction with AIBN/HSnBu3. You get a simple reduction (Barton decarboxylation).

But of course, the weak point of this plan, is how to make CO2, reactive?

[mir]

Hey, why not make carbon monoxide from CO2?

Carbon monoxide is a diradical, and would react with organic radicals, twice actually. You get a keto group inserted:

CO2 --> CO  (in some strange way)
R-I + SnBU3/AIBN -->  R*
R* + :CO -->  R-*CO
R-*CO --> R2CO

Then you might reduce the carbonyl group thorugh standard methods.

[Borek]

If one could only reverse oxalic acid oxidation...

5(COO)₂^2- + 2MnO₄^- + 16H⁺ -> 2Mn²⁺ + 10CO₂ + 8H₂O

[AhmedEzatAlzawalaty]

first post why u need oxygen from CO2 definitely itself.u could get reactive oxygen from decomposition of H2O2 or oxidizing agents for instance.

[billnotgatez]

Is it possible to heat carbon dioxide hot enough to separate it into carbon and oxygen?
I guess the upshot of my question is that given enough energy one could separate them.

[HP]

Thats wht i know as practical CO2 reduction reaction:
BaO2 + CO2 = BaCO3 + O2
You'll say where such a process can be useful...

[charco]

simply heating CO2 with carbon will form Carbon monoxide

[Yggdrasil]

But of course, the weak point of this plan, is how to make CO2, reactive?

Many biological systems fix carbon dioxide by reacting bicarbonate ions with biotin.  Many enzymes employ this strategy such as pyruvate carboxylase, acetyl-CoA carboxylase, and propionyl-CoA carboxylase.

[HP]

Also interesting and common is the so called Kolbe-Schmitt reaction usefull for practical acetylsalicilic acid preparation starting from Na-phenolate and dry CO2...
http://www.organic-chemistry.org/namedreactions/kolbe-schmitt-reaction.shtm

[Yggdrasil]

I guess you could also react CO₂ with a Grignard reagent to form a carboxylate.  However, this is most commonly done by pouring the Grignard reagent onto dry ice, so it probably wouldn't work easily with atmospheric carbon dioxide.

[HP]

Aha this is one more classical example for CO2 reactivity in organic chemistry but all these reactions are addition one not decomposing...In Grignard CO2 addition the dry CO2 gas could be obtained by passing "wet" CO2 true a Wolf's flask with conc.H2SO4 as drying agent. Dry ice is nice too I have some reminiscence of CO2 improved reactivity at  high temperatures may be something as the proposed by charco used in the Siemens-Martin steel oven process: 
C + O2 = CO2
2C + O2 = 2CO
CO2 + C reverse reaction to 2CO - Q

[Donaldson Tan]

simply heating CO2 with carbon will form Carbon monoxide

Provided it is at least 900C