Sciencemadness Discussion Board

Idea for Na production

Scratch- - 7-4-2005 at 16:15

I dont know much about the chemisty of sodium oxides/hydrides but here is my idea for sodium production. This would use only an inert atmosphere, sodium carbonate, hydrogen gas, and either pyridine or a suitable cruicible to melt sodium and its hydroxide in.

2 Na<sub>2</sub>CO<sub>3</sub> => 2 Na<sub>2</sub>O + 2 CO<sub>2</sub>
Na<sub>2</sub>O + H<sub>2</sub> => NaOH + NaH
NaOH + NaH + Na<sub>2</sub>O => 2 NaOH + 2 Na

The sodium carbonate is heated to decomposition to make sodium oxide and carbon dioxide (It starts to decompose at around 400*C).

Half by weight of the sodium oxide is exposed to hydrogen (Possibly with heat?) to produce sodium hydroxide and sodium hydride.

The sodium hydroxide and sodium hydride mixture is mixed with the other half of sodium oxide and heated to produce more sodium hydroxide and elemental sodium.

The sodium hydroxide is either dissolved in pyridine or heated untill it melts and the sodium can be scooped off the surface of the hydroxide.

The sodium hydroxide can be turned back into sodium carbonate by bubbling carbon dioxide through an aqueous solution of it.

Do you think this will work? I think its worth a shot but I wasnt sure about the sodium oxide and sodium hydride making elemental sodium and sodium hydroxide part.

[Edited on 4/8/2005 by Scratch-]

BromicAcid - 7-4-2005 at 18:18

The decomposition of sodium carbonate may begin to occur @ 400C but it is at an incredibly slow rate, so much so that it has a defined melting point of 854 C and it's not until nearly 1000 C that decomposition becomes measurable. So the first step would be a major pain in the butt. Better to just buy the sodium hydroxide, it is more readiy avalible, at least to me then sodium carbonate anyway.

And as for the last step, there is some eqiulibrium formed there, sodium metal reacts with sodium hydroxide at >400C to produce hydrogen and sodium oxide as products so it would have to occur at mild temperatures, and the middle step, I have not clue on the spontenaety proably would have to be under pressure and couldn't be greater then 200C otherwise the hydride decomposes.

[Edited on 4/8/2005 by BromicAcid]

Scratch- - 7-4-2005 at 19:13

Perhaps if I made a large CaSO<sub>4</sub> pot and put the NaCO<sub>3</sub> in it, I could build a fire around it. If I use alot of charcoal and build the fire in a hole lined with bricks it would reflect enough heat to decompose the NaCO<sub>3</sub>. It might be a good (And perhaps profitable) way to produce Na (Assuming the rest of the reaction works out, and if the H<sub>2</sub> doesnt need pressure) if its done in large batches. Na<sub>2</sub>O seems like it would be very useful also as a drying agent as it reacts with water to make the hydroxide, Na<sub>2</sub>O + H<sub>2</sub>O => 2 NaOH.

BromicAcid - 7-4-2005 at 19:20

If you would be willing to do that to sodium carbonate it would be easier to actually go straight to sodium, heating sodium carbonate with carbon gives sodium at about 1000 C or at least in that neighborhood. If you haven't already check the library, there is a little link at the top for the old library page and on that page is the pages that I scanned in and Polverone made into a PDF on sodium manufacture, chemical reduction methods of sodium salts being one of the main focuses.

Scratch- - 7-4-2005 at 19:37

Ah, I never noticed that. It looks like an interesting book! I'll read it over the weekend. Thanks.