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Author: Subject: Oxidation of ethanol
Sauron
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[*] posted on 31-3-2007 at 17:54


Gemtlemen, let's have some documentation.

@RG, what's your snippet from?

@Eclectic, it is very well known that a number of extremely ubiquitous microbes happily consume sugars and turn them into acetic acid, these bacteria multiply much faster than do yeasts and that is whywinemeakers operate microbiology labs on premises, They can't use biocides or they'd kill the yeast as well. Fermentation is anaerobic, these bacteria require air (oxygen) while yeast does not. In short there is always some acetic acid formed in wine via these imperfectly excluded bacteria

I suspect that any contribution by Cr in the SS alloy of the vat is down in the baseline noise level of the bacterial generation of AcOH -- which in any succesful fermentation is managed to be kept to an acceptable low level anyway.
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not_important
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[*] posted on 1-4-2007 at 03:18


Quote:
Originally posted by guy
I have a mixture of nickel and copper salts (from US nickel coins) I dont know how to separate it! grrr


Check the properties of NiSO4 and CuSO4, I believe copper sulfate decomposes around 650 C while nickel lasts until 840 C or thereabouts. Heating the mixture to 700 - 730 C should decompose the copper salt to the oxide, leaving the nickel salt. Having not tried this, I can't say that the mixture might behave differently that the isolated salts, or that you might need to leech out the NiSO4, dry, and heat once again.

If you overheat the NiSO4 also decomposes into the oxide. The mixed oxides can be extracted with hot dilute H@SO4, with dissolves the copper oxide. I don't know what 'dilute' is exactly, consult a text on nickel mining.

Other wet methods include precipitation of CuS from an acid solution, precipitation of cuprous iodide and iodine by adding a soluble iodide (only for countries where the element iodine and its compounds have not been outlawed), using dimethylgloxime to precipitate the nickel (only for people with deep pockets).

I would have tried starting with the metal alloy, and electro-refine it by plating copper from the alloy to a copper electrode in an acid solution, using a low voltage. The nickel would go into solution as the copper dissolves to be plated out on the other electrode.

Another method, when you have a mix that is mostly nickel, the finely divided metals (from reducing the oxides) can be treated by the Mond process to extract the nickel. As this involves carbon monoxide (toxic) and nickel carbonyl (more toxic) it is not a process for the amateur or to do at home, unless your home is very isolated and your will is up to date. But it is a elegant method.
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[*] posted on 1-4-2007 at 09:32


Just a thought, add iron filings or steel wool to give metalic copper and a mixture of nickel and iron salts.
Filter and add excess ammonia and bubble air through it. The iron ppts as Fe(OH)3 and the Cu stays in solution as the ammine complex.
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Eclectic
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[*] posted on 1-4-2007 at 12:21


@Sauron: The patent was teaching a catalytic O2 oxidation to esters with Cr as the catalyst, either added, or leached with HCl from the SS. No fermentation involved.
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[*] posted on 3-4-2007 at 06:59


chromatography? countercurrent extraction?
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Sauron
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[*] posted on 3-4-2007 at 22:26


@Eclectic, someone else (@JohnWW I believe) brought up the connection to viniculture in SS vats, it was not interjected by me. I was merely responding that that post.

It's hard to address the patent when you haven't posted it or remembered the number, isn't it?
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[*] posted on 5-4-2007 at 16:30


Another Nickel Peroxide article

Information on preparation of catalyst and procedures for oxidizing various alcohols. This example is for oxidizing saturated aliphatic alcohols.


Quote:

Experimental

Preparation of Nickel Peroxide.
-A mixture of 300 ml. of
6% sodium hypochlorite solution and 42 g. of sodium hydroxide
was added dropwise to 130 g. of nickel sulfate hydrate
in 300 ml. of water, and stirred for 0.5 hr. at 20".
The resulting black nickel peroxide was collected by filtration,
washed with enough water to remove active chlorine,
and, after crushing the cake to powder, dried over anhydrous
calcium chloride under reduced pressure.

Renewal of Nickel Peroxide.-After the oxidation reaction, nickel peroxide was collected by filtration, washed
with water, stirred with 6% sodium hypochlorite solution
(about ten times the quantity of nickel peroxide) for 20 min.,
filtered, washed with water, and dried.

Determination of Oxidation Rates for Saturated Aliphatic
Alcohols.
-To a solution of 0.04 mole of each alcohol and 2
g. of sodium hydroxide in 100 ml. of water, nickel peroxide
(1.5 times the theoretical amount) was added under stirring
on a magnetic stirrer, and the heterogeneous mixture was
allowed to react for the given times at various temperatures.
The solid was then separated from the reaction solution by
suction filtration and washed with water. The combined
filtrate was acidified with dilute sulfuric acid and a portion
accurately weighed out from the solution was steam distilled.
The volatile carboxylic acid in the distillate was
titrated with 0.1 N sodium hydroxide solution


Also, NiOOH can be used to oxidize chloroform to hexachloroethane in 72% yield

[Edited on 4/5/2007 by guy]

Attachment: jo01052a026.pdf (571kB)
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Sauron
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[*] posted on 5-4-2007 at 17:45


Yes, I noticed that, however it is not an exidation. It is a free radical initiation and dimerization. It implies that nickel peroxide might be useful as initiator for other FR reactions (in place of benzoyl peroxide or AIBN/SO2Cl2 systems for example)

However it is a little OT for this thread (like many of the other transformations described in the review).

Also, for many of us, CHCl3 is more valuable than hexachloroethane, unless you have an all consuming need to make Zn-based smoke bombs.
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[*] posted on 5-4-2007 at 18:48


It may be useful to know that nickel peroxide, NiOOH, also known as nickelic hydroxide, is the black material of the positive (+) electrode of a charged NiCd battery.



The single most important condition for a successful synthesis is good mixing - Nicodem
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Sauron
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[*] posted on 5-4-2007 at 20:03


For oxidation of ethanol, to acetaldehyde it is useless.

To acetic acid, in inert organic solvent it is very efficient.

For benzyl alcohol to benzaldehyde (in inert solvent) it is very efficient. 92%

For toluene to benzaldehyde and benzoic acid, it is claimed but no yield given.

For some other oxidations where we normally use KMnO4 it may be superior. Methylpyridines to nicotinic and isonicotinic acids for example.

Nickel peroxide's claim to fame is a very high ratio of available O2 to weight as compared to MnO2 etc. The potential of harvesting the powder from NiCd batteries rather than having to prepare it from bleach and soluble nickel salts is interesting and attractive. The applicability to numerous other transformations is also tantalizing.

[Edited on 6-4-2007 by Sauron]
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[*] posted on 10-4-2007 at 18:09
KMnO4 + EtOH + NaOH ---> Sodium acetate --> Acetic acid


I need some help with the oxidation of ethanol in the presence of KMnO4 and NaOH to yield sodium acetate. There is plenty of info on “put the alcohol, oxidant, and base into a flask and you will get the carboxylic salt), but little info on how much and for how long. And what type of work-up is required

Experiment:

A 250ml Erlenmeyer flask was charged with 50ml of 95% EtOH and ~.60g KMnO4 with stirring. The KMnO4 was allowed to dissolve upon to which 75ml of 3M NaOH was added. Immediately upon adding NaOH, the solution turned from deep pink to dark brown. A precipitate was noticed on the bottom of the flask. The solution was then heated to boiling for approximately 15 minutes. The solution was then gravity filtered to separate the precipitate.

The filtrate is clear orange and strongly basic, the precipitate is muddy brown.

I would like to issolate the sodium salt...but have no idea if any of the reagents were used in correct proportion.

- 3vil
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[*] posted on 18-4-2007 at 16:13


Activated DMSO can oxidize ethanol to aldehyde.
I have an article of review for that.
If you need it, Please contact me.
wjmed_at_126_point_com
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[*] posted on 18-4-2007 at 17:32


Quote:
Originally posted by Dr.3vil
...

I would like to issolate the sodium salt...but have no idea if any of the reagents were used in correct proportion.

- 3vil


Stoichiometry is your friend, and a good starting point. Sometimes an excess of a reactant is needed or helpful, but starting with balanced equations.

So start with balanced equations, use formula weights and liquid density values to determine the physical amount of the the reactants to use, and you most of the way there.
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[*] posted on 27-5-2007 at 19:03


Ok..I didnt want to use bleach because that would be too dilute. So I got a bunch of sodium dichloro-s-Triazinetrione (sodium dichloroisocyanurate)

Is there anyway to make a "bleach' solution out of this in situ. Like can I mix sodium dichloro-s-Triazinetrione, NaOH, NiCl2 and EtOH in one pot?

[Edited on 5/27/2007 by guy]
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Sauron
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[*] posted on 27-5-2007 at 20:23


The S in that name is not capitalized. If you capitalize it it means SULFUR of which there is none in this compound. The small s stands for sym. as in symmetrical, and the compound you are talking about is merely the monosodium salt of TCCA.
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[*] posted on 27-5-2007 at 20:38


Ok. so I tested it by adding some of the NaDCC with NaOH and hypochlorite is definietly formed. Ok good to go!

[Edited on 5/27/2007 by guy]

I added 68g NaOH to 100mL H2O and added that to an alcoholic solution of NiCl2*6H2O (10.17g) and 100mL of EtOH. The solution turned to a thick green sludge.
Then I added in portions, 158g of sodium dichlorocyanurate dihydrate. Each addition formed a brown coloration but quickly turned back to green along with a lot of heat! I foolishly did not use an ice bath (just plain water). I added the last portion too quickly and had a runaway reaction with ethanol and water boiling off vigorously.

Now I am left with the solids and tommorow I will try adding acid to see if acetic acid has formed.

[Edited on 5/28/2007 by guy]
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[*] posted on 28-6-2007 at 22:18


Indirect alcohol oxidation by electrolysis with Ni(OH)2 catalyst?

I have read a few journal articles on this method but they all used a NiOOH electrode. I am wondering if I can just electrolyze a slurry of Ni(OH)2 in alcohol? I have tried electrolyzing Ni(OH)2 by itself and it does indeed make NiOOH.
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