John paul III
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Performate salts by oxidation of formaldehyde with air
Formaldehyde reacts with air to give formic acid; I read somewhere that performic acid undergoes reaction with formaldehyde to give two formic acid
molecules. Could this be the way the first reaction proceeds? Wikipedia claims only aromatic aldehydes oxidize in air to peracids, but I suspect
that's only because the second reaction in this case is slow enough to separete the peracid easily, ergo formaldehyde should react forming HCOOOH too.
This brings me to the second question: how could one perticipate performate as a salt to prevent it from turning into formic acid? I thought of
generating colloidal suspension of Ca(OH)2 in situ, but this would catalyze canizarro reaction of formaldehyde potentially reducing the yield. I don't
want to use strong acid salts of Ca. Would adding more formic acid to solution be a viable way of reducing pH? (It would also slow the cannizarro
reaction and formic acid formation due to le-chatelier principle). Or would the cannizarro reaction be slow enough to not affect the yield too much?
[Edited on 1-7-2018 by John paul III]
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John paul III
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https://en.m.wikipedia.org/wiki/Peracetic_acid
Peracetic acid is prepared industrially from acetaldehyde with O2. I'll try digging to find how they supress the peracid+aldehyde reaction or if it is
only formaldehyde-performic acid specific reaction
[Edited on 2-7-2018 by John paul III]
[Edited on 2-7-2018 by John paul III]
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John paul III
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I knew I was right about the mechanism:
http://www.chemgapedia.de/vsengine/vlu/vsc/en/ch/2/vlu/oxida...
[Edited on 2-7-2018 by John paul III]
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John paul III
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https://patents.google.com/patent/US3228978
This one seems adaptable for a home chemist. Interestingly, acetic anhydride is formed as one of the byproducts depending on the conditions, perhaps
one could add a dehydrating agent and recover some of it
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tetraiodide
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I actually thinking, of making formic acid by oxidation of formaldehyde or paraformaldehyde, but I was thinking of using a stronger oxidizer like h2o2
or sodium hypochloride, haven't looked into it much but since holding tank different is wayyy easier to get than formic acid it seemed like easy
route, anyone have any thoughts/experience doing it that way?
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John paul III
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Quote: Originally posted by tetraiodide  | | haven't looked into it much but since holding tank different is wayyy easier to get than formic acid it seemed like easy route, anyone have any
thoughts/experience doing it that way? |
Did you mean to say that formaldehyde is easier to get than formic acid? Everything depends on where you live but i suggest you look for a scale
remover, some of them contain formic acid at ~40% concentration
[Edited on 3-7-2018 by John paul III]
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