08-26-04 18:12
No 527517
I´v found this procedure in an old thread, it´s look intresting for the production of Formic Acid. My knowledge are not enugh to evaluate it "critically".
Alternative method of production, by madscientist PREPARATION OF HYDROGEN CYANIDE FROM POTASSIUM PERMANGANATE, METHANOL, SULFURIC ACID, AQUEOUS AMMONIA, AND POTASSIUM HYDROXIDE
Notes:
-all potassium chemicals can be substituted with their sodium parallel, if mass ratios have been properly adjusted
-it is highly recommended that nbk2000 dismiss all described and inferred safety precautions
PREPARATION OF POTASSIUM FORMATE (HCOOK) AND MANGANESE FORMATE (Mn(HCOO)2):
126.4 grams of potassium permanganate (KMnO4) is added to 32 grams (approximately 40.2mL) of concentrated methanol (CH3OH):
10(CH3OH) + 8(KMnO4) --} 10(HCOOH) + 10(H2O) + 8(MnO) + 4(K2O)
10(HCOOH) + 10(H2O) + 8(MnO) + 4(K2O) --} 10(HCOOH) + 8(KOH) + 8(MnO) + 6(H2O)
10(HCOOH) + 8(KOH) + 8(MnO) + 6(H2O) --} 8(HCOOK) + 2(HCOOH) + 8(MnO) + 14(H2O)
8(HCOOK) + 2(HCOOH) + 8(MnO) + 14(H2O) --} 8(HCOOK) + Mn(HCOO)2 + 7(MnO) + 15(H2O)
Mixture is then filtered to remove the manganese oxide (MnO), and the filtered solution is then allowed to evaporate. What is left is a ratio of eight : one of potassium formate : manganese formate. The remaining crystals should weight approximately 81.77 grams if you acheived a 100% yield.
PREPARATION OF FORMIC ACID (HCOOH):
The mixture of potassium formate and manganese formate is added to concentrated sulfuric acid. That is, all 81.77 grams of the potassium formate and manganese formate crystals are added to 49 grams (26.5mL) of concentrated sulfuric acid. The remaining mixture is heated, and the vapors, which are composed of formic acid, are condensed. WARNING! FORMIC ACID IS TOXIC. PURE FORMIC ACID IS A COLORLESS FUMING LIQUID WITH A PUNGENT ODOUR; IT IRRITATES THE MUCOUS MEMBRANES AND BLISTERS THE SKIN.
8(HCOOK) + Mn(HCOO)2 + 5(H2SO4) --} 10(HCOOH) + 4(K2SO4) + MnSO4
Is that fasible?
(Hive Bee)
08-26-04 22:00
No 527552
possibly. If there is one thng i have learnt - complex synthesis of precursors will annoy, and the ones i have made seem simpler than the formic synth you describe...
If your in the US then formic may be a problem (is)
If your in the EU - buy some.
Otherwise - look for household chemicals.
Where I am at you can get formic OTC as 'kettle descaler'
ie hard water - chalk build up... %varies
however, does form an azeotrope so purification becomes complicated (Soxhlet - hectic..) if you want 85-95%
hope that helps a lil
(Hive Addict)
08-27-04 07:50
No 527726
i really dont like the first step with the permangenate oxidiser.... if you not SUPER carefull you will oxidise to CO2 and H2O.....
As its said you need to figure what conc you need.
You can make formic ala rhodiums site with oxalic and glycerol, if done PROPERLY you can get ~70% ish you need to titrate to find out proper conc.
Much easier than that method...
But if thats a problem you could do that way....
Would work well but just be very carefull with the acidification of the salts part.... that will run hot and let off formic vapours, and belive me i got a face full of them and it hurts like a mother fucker!
Take the req precautions.
-AC
Its just my opinion, but no-one listens to me anyway, and rightly so...
(Stranger)
08-27-04 18:54
No 527802
I have no problem getting formic in the states,you just have to tighten up and find that source.
S.I.A®
Got gunz©
S.I.A™
(Stranger)
08-27-04 23:21
No 527839
I´m very happy to read that the most luky guys can buy Formic acid or the precursor as in Rhodium write up.
The question is:
have someone already tried the above reaction or a similary reaction?I found UTFSE many document but no a finally word on it .Any experienced old bee maybe?
(Hive Bee)
08-27-04 23:43
No 527841
Isn't formic acid used as a silage preservative in the US?
Video meliora, proboque; Deteriora sequor. -Ovid
(Hive Bee)
08-27-04 23:51
No 527842
like a possibility
but if you feel like banging your head against the nearest wall..