seilgu
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Hydrazine process here outdated?
https://en.wikipedia.org/wiki/Peroxide_process
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Before invention of the peroxide process, the Bayer ketazine process had been commercialized. In the Bayer process, the oxidation of ammonia by sodium
hypochlorite is conducted in the presence of acetone.
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So it seems to me that currently the best method is to use Ammonia mixed with MEK, and then drip H2O2 (not bleach) slowly to get the ketazine.
But it seems that most people including NileRed, NurdRage, or Doug's Lab still uses the old method. Is there any danger to the H2O2 process? Or is it
because nobody wanted to risk trying the H2O2 process?
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njl
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Concentrated H2O2 is harder to get than Cl2 or bleach. As far as I know it's basically the same process using different oxidants. Interesting ideas to
me are straight Cl2 or dimethyldioxirane as oxidants. Thoughts?
Reflux condenser?? I barely know her!
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Elemental Phosphorus
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Quote: Originally posted by njl  | | Concentrated H2O2 is harder to get than Cl2 or bleach. As far as I know it's basically the same process using different oxidants. Interesting ideas to
me are straight Cl2 or dimethyldioxirane as oxidants. Thoughts? |
As far as I know the peroxide shouldn't have to be extremely concentrated, no? After all, 12% peroxide is OTC in most places, but it is true that
bleach is cheaper.
Anyway, I'm not sure it's really that no one has tried using hydrogen peroxide as the oxidant, I'm sure some home chemists have but the method with
bleach is simple and cheap.
I'd think that chlorine and dimethyldioxirane would have the same issue as oxidants. Interesting chemistry, but too dangerous or hard to get a hold of
to be a more practical process than bleach or peroxide.
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Alkoholvergiftung
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In the German Wiki they write as an lab methode. Bubbling Chlorine throught 20% Urea Solution and after this let it react with 20& NaOH Solution.
But i never hear that someone use this methode.
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Elemental Phosphorus
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| Quote: Originally posted by Alkoholvergiftung | | In the German Wiki they write as an lab methode. Bubbling Chlorine throught 20% Urea Solution and after this let it react with 20& NaOH Solution.
But i never hear that someone use this methode. |
Yes, this is the chlorourea process. Ordenblitz did it a while back:
http://www.sciencemadness.org/talk/viewthread.php?tid=1128&a...
I think his results are in that thread.
I can also understand that some people would not want to use a peroxide process on a large scale. Mixing concentrated hydrogen peroxide and MEK on a
large scale might make me a little nervous too..
(The addition of the ammonia should prevent the formation of methyl ethyl ketone peroxide, but accidents do happen.)
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njl
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For me 12 percent is available but oddly expensive. 3 percent is the next best thing, but that requires a large volume of water.
Reflux condenser?? I barely know her!
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XeonTheMGPony
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here 35% is available in 4L jugs for peroxide.
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UC235
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Bleach and urea are super cheap. Industry is very different from amateur.
We're not using the Bayer process, but a modified Raschig process. Using urea offers better reaction control and higher yield (50ish%) vs the original
http://orgsyn.org/Content/pdfs/procedures/cv1p0309.pdf
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seilgu
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https://patents.google.com/patent/CN104555953A/en
Here's a Chinese patent. See Embodiment 1 for an example.
I haven't tried it yet because I'm having problems with the bleach ketazine process.
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symboom
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| Quote: Originally posted by seilgu | https://en.wikipedia.org/wiki/Peroxide_process
| Quote: |
Before invention of the peroxide process, the Bayer ketazine process had been commercialized. In the Bayer process, the oxidation of ammonia by sodium
hypochlorite is conducted in the presence of acetone.
|
So it seems to me that currently the best method is to use Ammonia mixed with MEK, and then drip H2O2 (not bleach) slowly to get the ketazine.
But it seems that most people including NileRed, NurdRage, or Doug's Lab still uses the old method. Is there any danger to the H2O2 process? Or is it
because nobody wanted to risk trying the H2O2 process? |
I'm curious if a peroxy salt would be similar
Such as using zinc peroxide, sodium percarbonate, perborate or persulfate could be used with ammonia or urea to form hydrazine
Also could hydrazine be formed from ammonium sulfate and sodium hypochlorite or calcium hypochlorite to form a concentrated mixture.
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clearly_not_atara
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From an industrial perspective, ammonia is cheaper than urea in bulk, and, being a gas, offers convenient flow process engineering.
From a laboratory perspective, ammonia and urea are both very cheap, and urea doesn't smell bad and is easily stored as a pure chemical.
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njl
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Maybe the urea/h2o2 adduct would be useful here because it allows you to concentrate h2o2 and also combines both reagents into one solid.
Reflux condenser?? I barely know her!
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morganbw
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I am sorry for my thoughts, this thread, to me may confuse some armatures
and actually put them at risk.
Hydrazine is pretty effing dangerous. I would suggest those outside of industry to follow the proven methods that have been derived for armature use.
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macckone
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one reason not use the hydrogen peroxide method is cost.
bleach is considerably cheaper.
The ketazine method of purification also has significant loss.
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symboom
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@ morganbw I'm sure a lot that goes into it understands the danger and along with others here that are not a kewl. My suggestion is the pathway to see
if it is even possible for the curiosity and science. There are times when I'm focused on just getting the product at the cheapest way. At times it's
the most rare and to satify curiosity. At times is the lazy quick I just want to get to the product even if it cost more.At times it's to achieve the
highest yield.
[Edited on 5-3-2021 by symboom]
[Edited on 5-3-2021 by symboom]
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macckone
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The primary reason to use the ketazine modification is purity.
The primary reason to prefer the hypochlorite method over the hydrogen peroxide method is cost.
The hydrogen peroxide method would likely yield a cleaner starting product, but I haven't tried it.
Ammonia is cheaper than urea on an industrial scale.
On a lab scale there isn't much difference in cost but urea is easier to handle than ammonia gas.
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