Discussion Formate salts instead of formic acid for CO method?

[roseblade]

Delete and repost because I realized I put it in the wrong board.

Original post:

Tried the search function, don't see anyone else talking about this. I've seen several posters mention using formic acid and sulfuric acid to generate CO. I've actually had sulfuric acid for quite some time; it seems to be readily available in the US in relatively pure form. Formic acid, on the other hand, seems to only be available from chemical suppliers. I do, however, see some online listings for salts of formic acid (# Formate, replace # with any common cation). It seems that such salts should undergo a reaction where the formate ion is protonated to formic acid, and then further react to form CO and water. I don't have any information about the speed of the reaction, and there doesn't seem to be much information about this reaction in general. Has anyone else considered this method? If chemically viable, formate salts might be a more feasible option than formic acid directly.



Note/warning: Some sources say that the reaction between formic acid and sulfuric acid is exothermic, and could lead to thermal runaway if the reaction rate isn't carefully controlled.

 

[dustoff]

i know that sodium formate undegoes pyrolysis when heated:

2HCOONa -> (COO)2 Na2 + H2|
(COO)2 Na2 >290c -> Na2CO3 + CO|

it seems that reation of formic acid salts with h2so4 may need some heating too. if formates are reactive as sulphides some of which decompose even when added to water it may be a viable option.

 

[atre]

If I remember correctly, formic acid is one of the fewer chemicals that readily react at room temperature (in this context of making CO, of course). Its advantage is that it reacts so easily, simple. But it gives off acidic vapours... (both in aerosol form and gaseous phase), unless you filter/wash the contaminated gas.

Maybe there is a chemical that reacts at room temperature other than formic acid? I have no idea, sorry. The user "Intoxicated" is much more knowledgeable than me. Let's see if he sees this thread.

 

[roseblade]

i know that sodium formate undegoes pyrolysis when heated:

2HCOONa -> (COO)2 Na2 + H2|
(COO)2 Na2 >290c -> Na2CO3 + CO|

it seems that reation of formic acid salts with h2so4 may need some heating too. if formates are reactive as sulphides some of which decompose even when added to water it may be a viable option.

It looks like pyrolysis should work with any formate salt, but the temperatures seem awfully high. I found a paper describing the pyrolysis of calcium formate, but it required temperatures upwards of 500°C. According to Wikipedia, FWIW, ammonium formate decomposes to formamide and water at 180°C, and formamide decomposes into CO and ammonia at 100°C. Ammonia, however, is extremely noxious, so I don't know if that's really viable after all.

 

[dustoff]

It looks like pyrolysis should work with any formate salt, but the temperatures seem awfully high. I found a paper describing the pyrolysis of calcium formate, but it required temperatures upwards of 500°C. According to Wikipedia, FWIW, ammonium formate decomposes to formamide and water at 180°C, and formamide decomposes into CO and ammonia at 100°C. Ammonia, however, is extremely noxious, so I don't know if that's really viable after all.

in the reaction above sodium formate turns into sodium oxalate with the release of hydrogen before the oxalate decompose in sodium carbonate and carbon monoxide. maybe oxalates better suited for pyrolytic CO production if some laboratory gear available (i think it's feasible with dry distillation setup that can channel the fumes in a room or exit bag/gas mask). still CO is explosive in high concentrations just heating soidum oxalate on frying pan is a bad idea IMO.

 

[RadiantNumber]

I'm not chemist but formic salts with acid will give you formic acid or sth

 

[Intoxicated]

Preparation of CO by mixing sodium formate and sulfuric acid is demonstrated in this video

View attachment CO from sodium formate.mp4

If I had to choose between HCOOH and HCOONa, I'd prefer the salt, because it's much safer to work with and it doesn't emit irritating vapors when you just open the container with it.

 

[roseblade]

Preparation of CO by mixing sodium formate and sulfuric acid is demonstrated in this video

View attachment 208797

If I had to choose between HCOOH and HCOONa, I'd prefer the salt, because it's much safer to work with and it doesn't emit irritating vapors when you just open the container with it.

Much appreciated! Hopefully it will be able to scale up