Sciencemadness Discussion Board

Make Formic Acid

TheAMchemistry87 - 13-8-2012 at 19:53

Hey i am trying to make Formic Acid (HCOOH) by bubbling Carbon Monoxide (CO) gas into Methanol (CH3OH) and producing Formic Acid (HCOOH) is this a good process to produce Formic Acid (HCOOH)?

Make Carbon Monoxide

TheAMchemistry87 - 13-8-2012 at 19:58

Hey im trying to make Carbon Monoxide (CO) to make Formic Acid (HCOOH) . Is this a good process

Zn + CaCO3 → ZnO + CaO + CO

Or is there any other way to produce it pure?

woelen - 13-8-2012 at 23:05

I have doubts about whether this produces CO. I can imagine that the reaction proceeds further to ZnO, C and CaO. Do not expect this to be an easy synth, you'll need strong heating and a good vessel which withstands the strong heat.

Second, making formiates from CO is not easily done as well, at least not in a home or a lab setting. CO is rather inert and does not react with water, nor with a solution of NaOH in water. You need to bring the CO in contact with solid finely divided NaOH at a temperature of 150 to 200 Celcius and at high pressure. This can be done on an industrial scale, but again, it is very difficult to do this at home or in a lab.

In the lab, making formiates could be done by hydrolysing chloroform in strong alkaline solution. Chloroform can be made from ethanol and bleach and when excess NaOH is present, then the chloroform will further react to formiate. Next you need to add a strong acid to the mix and distill off all liquid. This will give you impure dilute formic acid.

woelen - 13-8-2012 at 23:41

Please, next time combine your questions into a single post.

No, this does not make formic acid. In your other thread about making CO from zinc and CaCO3 I give another method for making formic acid.

woelen - 13-8-2012 at 23:42

Further discussion can be done here: http://www.sciencemadness.org/talk/viewthread.php?tid=21186

This thread is closed, it is best to keep all discussion in the same thread.

watson.fawkes - 14-8-2012 at 03:41

Quote: Originally posted by TheAMchemistry87  
Hey i am trying to make Formic Acid (HCOOH) by bubbling Carbon Monoxide (CO) gas into Methanol (CH3OH) and producing Formic Acid (HCOOH) is this a good process to produce Formic Acid (HCOOH)?
This is indeed the reaction used industrially, but it's a 40 bar (or so) reaction. Unless you have the pressure vessel required, it's not for you.

For lab scale production, there's the route with oxalic acid and glycerol. Unlike the Wikipedia page for carbon monoxide, whose reaction with zinc and CaCO3 has no references, the page for formic acid has citations, including an old and freely-available paper on the oxalic acid route.

Dave Angel - 14-8-2012 at 09:33

Have a look at rhodium for formic acid syntheses applicable to a home lab.

Notably, one should not try distilling formic acid from formate and conc. sulphuric acid (as one might for nitric from nitrate) as CO is evolved. Unless you're after CO for some purpose other than making formic acid, it seems like something of a backwards step!

Depending on where you are, you may be able to obtain aqueous formic acid OTC as a descaler (Boots in the UK sells it as ATAKA). This can be fractionally distilled under reduced pressure with the right kit (e.g. perkin triangle). It does defeat the purpose of making the acid yourself, but this depends on whether you are just interested in having the end product or developing a process.

Hexavalent - 14-8-2012 at 09:52

One can often find descaler products OTC that contain formic acid, my own local brand at a concentration of 40%.

kristofvagyok - 14-8-2012 at 09:57

An easy method is descibed in the following paper: just distill some glycerol and oxalic acid. Formic acid will came over, it is an easy method for preparation of a small amount of formic acid.

Interaction of glycerol and oxalic acid
Frederick Daniel Chattaway
J. Chem. Soc., Trans., 1914,105, 151-156
DOI: 10.1039/CT9140500151

Also: long ago the common method to obtain some formic acid was to collect a lot of ant, put them in a retort and distill them... Anyone ever tried it?:D

vmelkon - 14-8-2012 at 12:28

Quote: Originally posted by kristofvagyok  
Also: long ago the common method to obtain some formic acid was to collect a lot of ant, put them in a retort and distill them... Anyone ever tried it?:D


No but my chemistry teacher told us about this. It would require a large amount of ants and it is messy. Then, people would take the formic acid and then add some acid to make CO. It is an easy laboratory way to make CO.
The decomposition section explains
http://en.wikipedia.org/wiki/Formic_acid#Decomposition

weiming1998 - 15-8-2012 at 04:03

Quote: Originally posted by watson.fawkes  
Quote: Originally posted by TheAMchemistry87  
Hey i am trying to make Formic Acid (HCOOH) by bubbling Carbon Monoxide (CO) gas into Methanol (CH3OH) and producing Formic Acid (HCOOH) is this a good process to produce Formic Acid (HCOOH)?
This is indeed the reaction used industrially, but it's a 40 bar (or so) reaction. Unless you have the pressure vessel required, it's not for you.

For lab scale production, there's the route with oxalic acid and glycerol. Unlike the Wikipedia page for carbon monoxide, whose reaction with zinc and CaCO3 has no references, the page for formic acid has citations, including an old and freely-available paper on the oxalic acid route.


I'm pretty sure that the reaction between methanol and carbon monoxide makes acetic acid instead of formic acid. Anyway, another way to make formic acid is by the haloform reaction with acetaldehyde (generated on site by oxidizing excess ethanol with hypochlorite). A formate salt, as well as chloroform, is produced. If you make the solution more alkaline, the chloroform will react, making more formate salts. Your only impurity then would be volatile acetaldehyde, ethanol and leftover chloroform, which you can get rid of by boiling the solution, and the hydroxide that you used to alkalise the solution. This solution can then be evaporated and formic acid synthesized from the formate salt and an acid.

watson.fawkes - 15-8-2012 at 08:37

Quote: Originally posted by weiming1998  
I'm pretty sure that the reaction between methanol and carbon monoxide makes acetic acid instead of formic acid.
Kirk-Othmer (4th ed., Vol. 11, p. 503) says otherwise. The product is methyl formate, which is then hydrolyzed to formic acid. Getting efficiencies of scale has a lot of interesting problems, and there's lots of patented processes and research about it. Interesting, but not amateur-scale.

watson.fawkes - 15-8-2012 at 08:39

Quote: Originally posted by kristofvagyok  
Interaction of glycerol and oxalic acid
Frederick Daniel Chattaway
J. Chem. Soc., Trans., 1914,105, 151-156
DOI: 10.1039/CT9140500151
This is the paper cited in the Wikipedia article on formic acid. Here the free version at HathiTrust.

AJKOER - 16-8-2012 at 10:58

Per Watt's (http://books.google.com/books?pg=PA649&lpg=PA649&sig... ) Formic acid is formed upon distillation of Oxalic acid with glycol, mannite, dulcite, erythrite and quercite. Per another source, the rapid heating of H2C2O4 produces Formic acid along with CO, CO2 and H2O (see page 3 at www.scribd.com/doc/30134128/Oxalic-Acid ) and the Formic acid can further decompose with the application of heat.

Note, I have an experience where my Oxalic acid (perhaps impure) decompose on me during the summer, so mild heat may induce a slow decomposition producing Formic acid that accelerates the decomposition of the H2C2O4 (per a comment at the Scrib link).


[Edited on 17-8-2012 by AJKOER]

Amos - 30-9-2014 at 12:23

So this thread hasn't seen some action for awhile. I'm trying to prepare some formic acid for carbon monoxide generation, using the process detailed here: https://www.erowid.org/archive/rhodium/chemistry/formic.acid...

I know that some of the stuff from Rhodium isn't necessarily too sound, so before I try to use up all of my glycerol, has anyone tried this synthesis before, or does it at least look pretty sound? It appears to rely on creating an ester, glyerine formate or glyceryl formate, in situ from oxalic acid and glycerol with some heating, though I can find almost no information on that substance. The ester is then hydrolyzed into glycerol, which is reused, and formic acid, which distills over.

I tried a mini-synthesis using about 25g glycerol and 25g oxalic acid, which yielded only a few ml of a somewhat cloudy liquid that distilled over between 90 and 100 degrees celsius. My product did react with baking soda, so I appear to either have gotten at least some formic acid or some oxalic acid that sublimated and came over with its own water of crystallization.