Method Formic+sulfuric acid, testing soon

[noidea1984]

By "testing" I don't mean I'm instantly going to attempt CTB. Rather I plan on trying to make some sort of homemade "distillation" where any unreacted acid condenses before it can exit into the air, while carbon monoxide is still able to get out. I should have everything in about ~3 weeks and I'll update then

 

[Intoxicated]

I'd recommend to consider HCOONa + H2SO4 as an alternative to HCOOH + H2SO4. I suspect that HCOONa + H2SO4 can produce a smaller amount of irritating HCOOH fumes, since methanoic acid is just an intermediate product in this reaction.

 

[noidea1984]

I'd recommend to consider HCOONa + H2SO4 as an alternative to HCOOH + H2SO4. I suspect that HCOONa + H2SO4 can produce a smaller amount of irritating HCOOH fumes, since methanoic acid is just an intermediate product in this reaction.

The problem I have with that is using sodium formate will result in the sulfuric acid becoming a reactant to form sodium sulfate. With only formic acid, the sulfuric acid will never actually be "used" since it's not much more than a catalyst. This way I can just add the sulfuric acid and pretty much forget and wait rather than having to worry about the reaction stopping if all the sulfuric acid is used up

 

[Intoxicated]

I find such an argument contrived. In some sense, H2SO4 is "consumed" with HCOOH too. The more H2O molecules taken from HCOOH are bound to sulfuric acid, the weaker dehydrating agent it becomes, this is why you can't use a small amount of it for decomposing a much bigger amount of HCOOH at a decent rate.

 

[stopthenoise]

This is also my preferred method. I have the chems, my concern is my lungs, they are very sensitive to chemical fumes creating irritation that will force me to panic and stop. I have seen the water filter method and I am wondering how well that removes irritants in the gas? Seems strange to worry about as I plan my CTB, but I am hoping for some knowledgeable opinions / advice. I appreciate any guidance.

 

[noidea1984]

I find such an argument contrived. In some sense, H2SO4 is "consumed" with HCOOH too. The more H2O molecules taken from HCOOH are bound to sulfuric acid, the weaker dehydrating agent it becomes, this is why you can't use a small amount of it for decomposing a much bigger amount of HCOOH at a decent rate.

You can still use a smaller amount with direct dehydration rather than adding an extra step in creating the formic acid. It makes even more sense to cut out the extra step when sodium formate costs more than formic acid itself. (95% formic acid is $187 for 5 gallons while I can only get 2.5 kilos of sodium formate for the same price)

 

[Endofpain]

People have made use of a improvised gaswasher. Formic acid is water soluble. The outlet of the reaction vessel is passed through a bucket of water.

I have played around with that setup myself and can tell you that in my opinion the gaswasher is somewhat neccesary for comfort.

If I were to used this method again, i would probably use a ground glass reaction setup with a reflux condenser equipped with icewater. This is then led through a drying tube containing carbonate.

 

[noidea1984]

People have made use of a improvised gaswasher. Formic acid is water soluble. The outlet of the reaction vessel is passed through a bucket of water.

I have played around with that setup myself and can tell you that in my opinion the gaswasher is somewhat neccesary for comfort.

If I were to used this method again, i would probably use a ground glass reaction setup with a reflux condenser equipped with icewater. This is then led through a drying tube containing carbonate.

The best I have is some buckets used for pool Chlorine storage and cleaning hoses. (Assuming the hoses are polyethylene) I'd probably be able to cut a hole through the lid to fit the tube through, then melt the cut part and use it to hold the tube in place. The tube would lead to a second bucket that's just water, and that's basically the gas washer

 

[Intoxicated]

(95% formic acid is $187 for 5 gallons while I can only get 2.5 kilos of sodium formate for the same price)

Are you going to kill Godzilla?

 

[pthnrdnojvsc]

I find such an argument contrived. In some sense, H2SO4 is "consumed" with HCOOH too. The more H2O molecules taken from HCOOH are bound to sulfuric acid, the weaker dehydrating agent it becomes, this is why you can't use a small amount of it for decomposing a much bigger amount of HCOOH at a decent rate.

So would 2 times the amount for example 2 liters sulfuric acid be needed for 1 liter of Formic acid

Would that be enough for a 10 foot by 6 foot shed, what level of co would 1 liter of Formic acid produce in a 10 by 6 foot container. Or 400 cubic feet ?
400 cubic feet is 11327 liters

a weather pod pop tent is 80 cubic feet 2265 liters .

would require production of 45 liters of carbon monoxide in that tent to reach 2%

would require production of 227 liters of carbon monoxide in that shed to reach 2%

23.2 grams formic == 1 liter of carbon monoxide .

There are 115 g of formic acid in 100 ml of \(95\%\) formic acid solution.

so rough estimate 20 ML formic produces 1 liter carbon monoxide.

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[noidea1984]

Are you going to kill Godzilla?

I'm not taking ANY chances of failure, so I guess you could say that

 

[Depressive_Thoughts]

Be careful to not end up killing yourself in the process of finding out if that mixture might actually kill you or not (sarcasm)

 

[Intoxicated]

So would 2 times the amount for example 2 liters sulfuric acid be needed for 1 liter of Formic acid

I saw people using even 1:1 proportion, but they heated the mixture in order to speed up the reaction. PPH 2022 recommends 250 ml of H2SO4 + 50 ml of HCOOH. I suspect that there is no a generally accepted standard optimal proportion, after all it's a matter of what yield you want to get within some amount of time.

23.2 grams formic == 1 liter of carbon monoxide .

The theoretical max yield of CO from HCOOH is 22.4 liters at 0 °C or 24.0 liters at 20 °C from 46 g of HCOOH. Of course, you probably wouldn't want to wait for completion of the reaction, and some part of CO may be wasted somewhere, so the real effective yield should be expected to be much smaller, but your estimations look too pessimistic nevertheless. I think, it would be safe to assume that you can obtain 1 liter of CO out of 10 g of formic acid in a reasonable time without heating the mixture (if the reaction takes place in an environment with temperature at 20 °C).

50 ml of concentrated formic acid should suffice for reliable CTB if you use a plastic bag. I don't see a point in filling tents or larger spaces with CO.

 

[atre]

I don't see a point in filling tents or larger spaces with CO.

If you mean an "exit bag" kind of mechanism, I can see the point of filling tents with gas. Some people (like me ) have trouble making their own exit bags. I know there is a text guide on how to make one in PPH, but unless there is a video instruction on it I don't see myself ever succesfully making a working bag with the tape over the neck, non-leaking and all.

Unrelated, but I wonder if you can inhale CO (or H2S) from a balloon. Granted that the balloon is high quality and does not leak, I don't see why not.

 

[noidea1984]

I saw people using even 1:1 proportion, but they heated the mixture in order to speed up the reaction. PPH 2022 recommends 250 ml of H2SO4 + 50 ml of HCOOH. I suspect that there is no a generally accepted standard optimal proportion, after all it's a matter of what yield you want to get within some amount of time.

The theoretical max yield of CO from HCOOH is 22.4 liters at 0 °C or 24.0 liters at 20 °C from 46 g of HCOOH. Of course, you probably wouldn't want to wait for completion of the reaction, and some part of CO may be wasted somewhere, so the real effective yield should be expected to be much smaller, but your estimations look too pessimistic nevertheless. I think, it would be safe to assume that you can obtain 1 liter of CO out of 10 g of formic acid in a reasonable time without heating the mixture (if the reaction takes place in an environment with temperature at 20 °C).

50 ml of concentrated formic acid should suffice for reliable CTB if you use a plastic bag. I don't see a point in filling tents or larger spaces with CO.

If I can get my home-made "gas washer" setup completed I'll probably make another extension where I can just breathe through the tube. 1.25% is enough to kill me in under 5 minutes so chances are a much higher concentration will have an even faster effect. Maybe then I could get a much lower amount and still achieve the same effect.