Chemgineer
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Oxalic acid
I'm having a go at producing oxalic acid from sucrose and nitric acid. It has now been banned where I am unbelievably!
The reaction seems to consume so much nitric acid though, 500ml for 100g of sucrose that it becomes very expensive.
Nevermind i'm only producing it for interest of the process.
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j_sum1
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Weird that you can't get oxalic acid but still have access to nitric.
The world of regulations is a strange place.
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Chemgineer
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Quote: Originally posted by j_sum1  | Weird that you can't get oxalic acid but still have access to nitric.
The world of regulations is a strange place. |
I should have been clearer, I can't get nitric acid either.
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Precipitates
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If you only need small quantities, it may be worth extracting it from plants (they are not restricted, yet  ).
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Alkoholvergiftung
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Alternative the Sodium salt was made when NaOH is molten together with Sawdust.This was the prevered methode because no NOx gases. KOH is better
because of the high price an mix of KOH and NaOH was used the result was purificated with CaOH as insoluble Calciumoxalate.
[Edited on 5-9-2024 by Alkoholvergiftung]
[Edited on 5-9-2024 by Alkoholvergiftung]
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Keras
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Can’t oxalic acid be made by oxidation of glycol using potassium permanganate?
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bnull
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| Quote: Originally posted by Chemgineer | | I'm having a go at producing oxalic acid from sucrose and nitric acid. It has now been banned where I am unbelievably! |
Oxalic acid banned? You're kidding, right?
@Keras: Oxalic acid is oxidised to CO2 by permanganate. The reaction is also autocatalytic, so it may not work as expected. Possibly some
other oxidiser (dichromate?), or permanganate with calcium hydroxide (will calcium oxalate be attacked?).
Quod scripsi, scripsi.
B. N. Ull
P.S.: Did you know that we have a Library?
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Sulaiman
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UK >10% regulated,
https://www.gov.uk/government/publications/licensing-for-hom...
The lists get longer each time that I look 
CAUTION : Hobby Chemist, not Professional or even Amateur
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woelen
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Things in the UK are really bad, even worse than in the rest of the EU. Here, we only have explosives precursor regulations
(KClO3/KClO4/NaClO3/NaClO4/HNO3/H2SO4/H2O2/CH3NO2/NH4NO3). All the other limitations, given in the provided link, like the one for oxalic acid, do not
apply here. I can buy oxalic acid without problems. Concentrated HCl also is no problem here.
Many sellers over here do impose additional limitations on the sale of chemicals, but frequently this only is asking for a End User Declaration, which
should describe what you intend to do with the chemical, combined with a limit of the amount you can buy in a year (frequently 1 liter/1 kilo,
sometimes limited to 100g, such as for iodine or magnesium powder). I can live with such limitations on what you may buy. It is sufficient for me, I
never use more than 1 liter / kilo per year of any chemical and even 100 grams is sufficient for me in the case of iodine or magnesium powder. At
least we still can obtain these chemicals 
[Edited on 5-9-24 by woelen]
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Chemgineer
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I failed, I boiled the solution down to dryness because I was distracted. I now have brown tar in the beaker. Expect this might be unreacted
sucrose.
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DraconicAcid
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Unreacted, partially reacted...sounds like a mess.
Dissolve what you can in aqueous base, and see what precipitates with calcium.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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Fulmen
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It can be prepared from sodium formate: http://www.sciencemadness.org/talk/viewthread.php?tid=107579
We're not banging rocks together here. We know how to put a man back together.
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bnull
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@Chemgineer: As @DraconicAcid said, unreacted and partially reacted sucrose, plus possible products from the interaction of sucrose and oxalic acid.
It's really a mess. There may be substances together with oxalic acid that would precipitate calcium. But it's quite possible that most of them are
soluble in water when you add an acid to separate them from calcium. I should have asked this before: did you use vanadium oxide as catalyst?
@Alkoholvergiftung: The downside in making oxalic acid from fusing sawdust and sodium hydroxide is the generation of carbon monoxide. Acetic acid is
formed during the process, about one part of acetic acid for each three of oxalic acid produced, but it can be removed during purification.
Quod scripsi, scripsi.
B. N. Ull
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chloric1
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Christ almighty! How absurd! Makes showing up in some random other country with nothing and no money but more liberty would be preferable than
living with those regulations! Other than that, how would one fight these regulations diplomatically? How hard is it to get an EPP license anyways?
Could you find a corporate or academic chemist to assist and convince them you are not a threat? Is there a business you could start that would make
getting an EPP license easier to obtain?
Fellow molecular manipulator
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Precipitates
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| Quote: Originally posted by chloric1 |
Makes showing up in some random other country with nothing and no money but more liberty would be preferable than living with those regulations!
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That's what I did! Sure I have to choose between buying food and chemicals some weeks, but at least I can buy them - "as much nitric acid as I can
eat".
About licenses, I'm not sure if anyone on here has managed to obtain one on the grounds of being a "hobby" chemist.
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Keras
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| Quote: Originally posted by woelen | | …but frequently this only is asking for a End User Declaration, which should describe what you intend to do with the chemical…
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What do you write when you have to fill one of those EUD?
Tot ziens!
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chloric1
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Yeah chemical hobbyist does not sound disciplined but rather whimsical. We all know we like various colors, smells and bangs but we must come across
as obedient and diligent. Even green energy and environmental advocacy requires testing reagents of some kind. Maybe you have a pond nearby you
suspect is contaminated with nitrates and you need 1L of 98% Reagent grade sulfuric acid to perform the “brown ring” tests. Or somehow get
involved with the dye industry somehow. Dyes need acids, bases, oxidants and reducing agents. Say you are trying to come up with a closed loop
production process that generates less wastes.
Fellow molecular manipulator
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Keras
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| Quote: Originally posted by bnull |
@Keras: Oxalic acid is oxidised to CO2 by permanganate. The reaction is also autocatalytic, so it may not work as expected. Possibly some
other oxidiser (dichromate?), or permanganate with calcium hydroxide (will calcium oxalate be attacked?). |
Oxone? Hypochlorite? Ammonium persulphate? Hydrogen peroxide?
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bnull
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Ozone is probably too strong and hypochlorite may chlorinate the intermediates somewhere along the path (or decompose them to phosgene). Peroxide and
persulfate seem a good choice, along with dichromate. I'd have to consult March's, wherever I've put it this time.
Or perhaps alkaline permanganate. If I'm not mistaken, that autocatalysis happens in acidic solution, and using permanganate and calcium hydroxide
simultaneously could work. It has probably been reported here some time in the past.
Edit: There's always the possibility of having a second job, even if it amounts to rarely performing that job. Sir Lawrence Bragg was a gardener, for
example. I do some gardening, electronics, plumber and electrician services. Nothing that requires a professional certificate or licenses but enough
to order stuff without raising too many eyebrows.
[Edited on 7-9-2024 by bnull]
Quod scripsi, scripsi.
B. N. Ull
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Keras
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It was really Oxone™, not ozone. Potassium peroxymonosulphate, if you prefer
Thanks for all the rest, I’m going to have a look at the Merck index.
Edit: The Index says it can be done ‘…heating sodium formate in
the presence of NaOH or Na,CO;’
[Edited on 8-9-2024 by Keras]
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Fulmen
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Correct, see my previous post.
We're not banging rocks together here. We know how to put a man back together.
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bnull
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O_o... I've been plagued by "x" in place of "z" so many times...
Oxone™ may work as good as peroxide or persulfate. I think you would need iodobenzoic (or was it iodosobenzoic) acid or TEMPO as catalyst.
Still, ozone (with a "z") is probably too strong; periodic acid and lead tetraacetate are too strong as well.
Quod scripsi, scripsi.
B. N. Ull
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RU_KLO
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patent: US3691232A
key aspects:
"Oxalic acid is produced at high yield by the oxidation of ethylene glycol with an acid mixture comprising 2-60 wt percent nitric acid 20-78 wt
percent sulfuric acid and 20-50 wt percent water. The molar ratio of nitric acid/ethylene glycol should not be less than 3/1.
..the concentrations and the ratios to ethylene glycol of nitric acid and sulfuric acid have a great influence on the reaction rate, yield of oxalic
acid, ratio of the formation of nitrogen monoxide versus nitrogen peroxide as well as on economics of the process.
Suitable concentration range is indicated in the attached drawing. The preferable concentration range comprises 2 to 60 wt percent nitric acid, to 78
wt percent sulfuric acid and 20 to 50 wt percent water. The molar ratio of nitric acid/ethylene glycol should not be less than 3/1. If ethylene glycol
exceeds this ratio, nitric acid become insufficient and a reductive environment is formed.
Reaction temperatures influence not only the reaction rate but also the selectivity for the formation of the desired product. The reaction may be
carried out at a temperature ranging from room temperature to 100 C., but preferable range of the reaction temperature is from 60 to 100 C.
Therefore, it is not preferable to add nitric acid in a dropwise manner to ethylene glycol, or to add ethylene glycol to a dilute solution of nitric
acid. It is necessary to choose reaction condition so that ethylene glycol is always not in theoretical excess over nitric acid
Ethylene glycol or its aqueous solution may be added in dropwise manner to the acid mixture solution so that the components in the reaction mixture
will fall in the above mentioned concentration range
EXAMPLE 1
In a 500 cc four necked reaction vessel provided with a stirrer, a dropping funnel, thermometer and a reflux condensor to which bubbling bottle and a
gas holder were connected,
153 g of 97 wt percent sulfuric acid,
147 g of 63 wt percent nitric acid and
80 g of water were charged.
The air in the whole reaction system was thenreplaced with helium. The acid mixture was heated to 80 C. and maintained at this temperature. A solution
of 18.6 g of ethylene glycol in 24.5 g of water was added in a dropwise manner to the mixture over a period of 1 hour.
During the reaction, the mixture was maintained at the same temperature. After 2 hours from the completion of the ethylene glycol addition, the yield
of oxalic acid reached 84 percent, and after 5 hours 94 percent. Neither nitrogen gas nor nitrogen monoxide which is not recoverable formed
"
Maybe it could be done, in not a controlled atmosphere.
Go SAFE, because stupidity and bad Luck exist.
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clearly_not_atara
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| Quote: Originally posted by Alkoholvergiftung | Alternative the Sodium salt was made when NaOH is molten together with Sawdust.This was the prevered methode because no NOx gases. KOH is better
because of the high price an mix of KOH and NaOH was used the result was purificated with CaOH as insoluble Calciumoxalate.
[Edited on 5-9-2024 by Alkoholvergiftung] |
This is one of those things where it's really helpful to have an actual procedure because the immediate product of the rxn is usually a "complex
mixture" from which some oxalate can be obtained by a less than obvious method.
Remember that sodium oxalate is poorly soluble in water (~3%) while potassium oxalate is highly soluble. However, potassium also forms the
tetraoxalate (KH3Ox2) which is poorly soluble (~2%).
In fact this was the subject of an undergraduate thesis in the 1920s:
https://thesis.library.caltech.edu/487/
| Quote: | This investigation was undertaken to find the best method of preparing oxalic acid from sawdust, either by one of the methods described in the
literature or a modification of it. The first work consisted in following the procedure recommended by a previous experimenter in order to become
acquainted with the methods which are now used and to discover their weak points. The procedures used commercially, and the experimental work of
Thorn, described in "Utilization of Wood Waste" by E. Hubbard form the basis of the work. No recent literature could be found on the subject, the work
of Thorn having been done nearly forty years before. Various commercial processes use slightly different methods; one uses KOH alone in the fusion and
precipitates MgC2O4 by adding MgCl2 to the K2C2O4 solution; in another a preliminary fusion is carried on in a vacuum at 180°, followed by the
regular fusion yielding a nearly colorless product. A process similar to that outlined by Thorn is also used.
The heating of sawdust with KOH results in the production of oxalic acid. Since NaOH is much cheaper, it is desirable to substitute it for KOH as far
as possible. Thorn found that a mixture containing 40% KOH and 60% NaOH by weight gave almost as good a yield, when heated in thin layers, as pure
KOH. The yield dropped off rapidly with a decreasing KOH percentage below 40%. He also found that the most satisfactory melt was made by using one
part of sawdust to two parts of lye, striking a balance between large percentage yield from lye with more sawdust, and more organic impurities which
are hard to remove if more sawdust is used. Soft wood gives a better yield than hardwood, and pure sawdust gives a better one than lignose left after
treating cellulose with HCl. |
Here it is evident that it is the potassium oxalate which leaches into solution and can then be pptd to obtain the product.
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