Hello All,    I posted a similar question to sci.chem.electrochem, but got no response in 5 days, so maybe one of you gentle people will answer this question...  Assuming you used suitable temps and pressure to keep CO2 liquified, could you directly electrolize the C and O2 components like H20 can be done? I've seen de_script_ions of processes that use molten salts at 1000 C with multistage reactions but I don't know if that was for efficiency, use at a standard pressure, or because thats the way its done...   So, can it be done; does it produce something else, ie CO and O instead; and where can I find the info on this. It seems very hard to get info on CO2 chemistry, especially how to break it down without using plants/algea of some kind.   Thankyou very, very much for any info or references you can supply. (Incase you wonder what this has to do with space, I am interested in terraforming and Venus in particular... Posts or direct email would be great - Thankx again!                                 Take Care All                                 David Sandman                                 This e-mail address is being protected from spam bots, you need JavaScript enabled to view it

...I've seen de_script_ions of processes that use molten salts at 1000 C with multistage reactions but I don't know if that was for efficiency, use at a standard pressure, or because thats the way its done... I believe it's for efficiency. However, the process I'm most familiar with is using heat and a porous _meta_l to produce O2 and CO, not going all the way to O2 and C. That process doesn't require compressing and liquifying the CO2; the whole thing is done on a heated and slightly compressed gas.                                                 Frank Crary                                                 CU Boulder

Hello All,    I posted a similar question to sci.chem.electrochem, but got no response in 5 days, so maybe one of you gentle people will answer this question...  Assuming you used suitable temps and pressure to keep CO2 liquified, could you directly electrolize the C and O2 components like H20 can be done? I've seen de_script_ions of processes that use molten salts at 1000 C with multistage reactions but I don't know if that was for efficiency, use at a standard pressure, or because thats the way its done...   So, can it be done; does it produce something else, ie CO and O instead; and where can I find the info on this. It seems very hard to get info on CO2 chemistry, especially how to break it down without using plants/algea of some kind.   Thankyou very, very much for any info or references you can supply. (Incase you wonder what this has to do with space, I am interested in terraforming and Venus in particular... Posts or direct email would be great - Thankx again!                            Take Care All I very much doubt it, since CO2 is covalently bonded. Just as pure water does not electrolyze, but needs a drop of e.g. H2SO4 to provide the ionization for the classical classroom demonstration. jk

 So, can it be done; does it produce something else, ie CO and O instead; and where can I find the info on this. CO is produced as an intermediate and converted into solid C (which is filtered out) and CO2.   Some references in the open literature are: Isenberg & Verostko (1989) SAE paper 891506 Chullen, Heppner and Sudar (1988) SAE 881041. Alan

could you directly electrolize the C and O2 components like H20 can be done? Sure. Just about any liquid can be electrolized. The problem is the voltage and power required. I don't recall the numbers, but I think it's quite difficult to do with CO2.                                                Frank Crary                                                CU Boulder   wait, If you would cool CO2 to liquid (which can only be done at a presure of more then 5 atm) and electrolize it, you would get soild carbon on the catode, which will also act as an isolator and stop any more CO2 from being broken.  but if it will be possable, it could be powered by solar cells, and be used in space suit on long repair missions (the ship will use plants to syntisize the O2 need).

  wait, If you would cool CO2 to liquid (which can only be done at a presure of more then 5 atm) and electrolize it, you would get soild carbon on the catode, which will also act as an isolator and stop any more CO2 from being broken. I thought that solid carbon was a conductor. Aren't the electrodes in arc lamps made from solid carbon? Didn't Eddison's early lightbulbs have carbon filaments?