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flakten
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Clorine gas WITHOUT sodium hypochlorite
Hello, I'm fairly new to this forum. Have read it many times but haven't had anything to add. Now I need help with a subject, hoping that you can help
me.
I'm looking for a way to produce chlorine gas without using neither sodium hypochlorite nor potassium permanganate.
Why?
Sodium hypochlorite is available as bleach in most countries. However here in Sweden there was a problem in the 90:s when children found "firecracker
recipes" on line. Many of them used sodium hypochlorite to produce sodium chlorate. Mixed with various fuels it's a cheap but very sensitive
explosive. After a few kids blew themselves up, hypochlorite bleach was replaced by other types of bleach and now hypochlorite is virtually impossible
to find.
Permanganates can be used with sulphuric acid and sodium chloride to make chlorine gas but manganese is fairly toxic and I have no way to handle the
waste. I have proper methods for handling the waste products from my experiments but manganese compounds are problematic. I'm not going to pour
manganese waste slurry into the drain. I know chlorine gas is also fairly toxic, but the chlorine gas is a necessity here, using manganese can be
avoided.
Goal
Chlorine gas for use as a reagent. For my purposes I don't need very pure gas, I intend to dissolve the gas by bubbling it into the precursor +
catalyst solution.
I have several experiments I want to do, the purity of the chlorine gas is not very important for any of them. Assuming that the gaseous
impurities are either common atmospheric gasses and/or insoluble gasses. Solvent in the reaction vessel will be water (distilled) in all the
experiments I have planned.
Resources
For the discussion I'm omitting all the safety concerns and similar resources. Otherwise we'll end up with a full textbook's worth of warnings and
similar.
Acids are very difficult to get in Sweden, at least the useful ones. I have access mainly to various concentrations of dilute nitric
acid and various concentrations of dilute hydrochloric acid. I can get sulphuric acid but that is a major headache, I'd like
to avoid it if possible. Except for acids, I can get anything you can get from common internet suppliers.
To answer the question, I don't want to import regulated acids, although I have nothing illegal to hide, getting a visit from the police after a
customs incident is never fun. Hypochlorite is not regulated but if customs find you're importing a bottle you will probably end up in the "criminal
surveillance and suspicion registry" which can cause problems in the future.
Thank you for an outstanding forum, I appreciate all the help you can give me.
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elementcollector1
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If you can find trichloroisocyanuric acid (TCCA), your problem is solved - it generates a clean stream of chlorine gas upon reaction with HCl, and
only water scrubbing is needed.
Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
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Dan Vizine
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The standard laboratory preparation of dry Cl2 is to simply heat CuCl2 strongly.
I think Sweden must be as looney as the US, worse even.
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Praxichys
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Do you have access to pool chlorination chemicals? "Pool shock" is about 60% calcium hypochlorite, and chlorinating tablets are either
trichloroisocyanuric acid or a mono- or disodium salt of di or monochloroisocyanuric acid, respectively.
Mixed with just about any acid (the dilute HCl would be fine), either of these two will generate wet chlorine.
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gdflp
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Try electrolyzing sodium chloride in a split cell, chlorine will be produced at one anode and hydroxide ions and hydrogen will be produced at the
other. If you scale this up you should be able to get a decent flow of chlorine at a really cheap price. The only problem with this method is that
as the hydroxide becomes evenly mixed in the solution it will start dissolving chlorine and turning it into hypochlorite. Electrolyzing hydrochloric
acid would be even better, hydrogen will be generated at one electrode and chlorine at the other. Separation of the electrodes will allow for
separation of the gasses.
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flakten
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Thank you all for your replies, now I have a good selection of methods with materials available.
This really is an outstanding forum.
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flakten
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In many aspects, yes. It's good that people who don't know what they're doing can't get the items, but sometimes I'd really like to be somewhere where
the laws are just a little bit more forgiving...
But if there were no challenges I'd just get bored and find something different to do.
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WGTR
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Dang, gdflp beat me to this.
One way that you can make chlorine is electrochemically. Electrolyzing hydrochloric acid will produce both hydrogen and chlorine. A graphite anode
must be used, as it is resistant to the chlorine in a neutral or low pH solution.
You can also electrolyze a concentrated solution of everyday sodium chloride, but you should use a divided cell in this case. Otherwise, the pH
gradually will rise around the anode, generating both bleach and increasing amounts of oxygen as the pH rises. This isn't so much of a problem
except that the graphite anode will begin to deteriorate under these conditions.
The way I would probably do it is with sodium chloride, because I like hurting myself with sharp objects (joke). I made some clay out of 40% grog,
40% A.P. Green fireclay, and 20% OM4 ball clay. After ramping the temperature carefully from 400-750°C (to drive off the chemically bound water), the
clay was fired low at 1000-1100°C for about an hour. It seems to hold up to a strong sodium hydroxide solution, and the material works as a
suitable diaphragm, although there are a few volts of drop across it. Alternately you could try using a small unglazed clay flower pot. The idea
is to separate the cathode and anode compartments from each other, allowing ionic conduction, but minimizing the bulk diffusion of the anolyte and
catholyte into each other.
The pH will rise around the cathode, and pH paper will become bleached at the anode as chlorine is separated. If the graphite anode begins to
deteriorate, it's time to change out the solutions with fresh ones. It's theoretically possible to add fresh chloride with the addition of HCl, but
you will get a bad case of ChlorineInTheFace (bleach + HCl = chlorine!).
I haven't made chlorine this way in a while, but when I did, I collected it with a large 60mL syringe barrel. You submerge it almost all the way in
the solution, and connect a hose to the outlet of the barrel. The anode gets put inside the barrel, which collects the chlorine. This way, you can
get up to a few inches of water pressure. That gives the chlorine enough pressure to bubble out into whatever solution you are delivering it to.
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flakten
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Would trichloroacetic (trichloroethanoic) acid work as well?
My regular supplier has that in store.
[Edited on 4-9-2014 by flakten]
[Edited on 4-9-2014 by flakten]
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flakten
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Very useful, thank you. I have an electrolysis apparatus somewhere in my basement.
[Edited on 4-9-2014 by flakten]
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Metacelsus
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No. If you look at the structures, you will see how they are different.
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flakten
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Ok, now I know what to get.
Thank you for your help!
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unionised
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No it isn't.
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Dornier 335A
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Flakten, sodium hypochlorite is still available as 3% solution called "klorin" in every supermarket. TCCA and NaDCC can be bought at
Biltema as pool chemicals.
Sweden is not that bad when it comes to chemicals. You can get most stuff if you know what you are doing.
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Siggebo
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"Klorin" brand is sodium hypochlorite, as previously pointed out. Other, cheap brands of bleach may be hypochlorite, possibly with surfactants.
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Dan Vizine
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I would refer you to "The Synthesis and Characterization of Inorganic Compounds" by William L. Jolly. Just look for the index heading "Gases, dry
chemical sources".
This is a well known equilibrium process between Cu (I), Cu (II) and Cl2.
[Edited on 21-9-2014 by Dan Vizine]
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AJKOER
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To quote Wikipedia on MnO2 (link: http://en.m.wikipedia.org/wiki/MnO2 ):
"The reaction of hydrogen chloride with MnO2 was used by Carl Wilhelm Scheele in the original isolation of chlorine gas in 1774"
MnO2(s) + 4HCl(aq) → Cl2(g) + MnCl2(aq) + 2H2O(l)
New dry cell batteries could be a source for MnO2, but usually with a strong base like KOH so carefully wash the MnO2.
With respect to a source for HCl, if you cannot buy cheap iron contaminated Muriatic acid, react NaCl with battery acid (H2SO4), or with a spa pH
control chemical like NaHSO4, or buy a strong organic acid like Oxalic acid.
[Edit] If you have found a source for NaOCl, but wish to avoid storing strong acids around children and others, add to the NaOCl vinegar, copper
metal, aluminum foil and some sea salt. This is the making of a so called bleach battery that I have discussed previously on SM. Here is an extract:
Quote: Originally posted by AJKOER  | Actually, here is a more useful way (actually, it makes the so-called bleach battery that you can use to produce electricity as well) to make some
Chlorine. Steps:
1. Mix bleach (NaOCl) and vinegar (which contains Acetic acid HAc) in the volume ratio 1.4 parts of 5% vinegar to one part of 8.25% extra strength
chlorine bleach.
2. Add a piece of copper metal which will function as the cathode.
3. Add an Aluminum source to act as the anode (finely cut up Al foil, for example, will also work).
4. Add a touch of sea salt (better than NaCl) to act as the electrolyte to get things started.
My take on the chemistry:
The creation of Hypochlorous acid:
NaOCl + HAc --> HOCl + NaAC
And, on the major electrochemical reactions:
H2O <--> H3O + OH-
At anode: Al + 3OH- ⇒ Al(OH)3 + 3e-
At the cathode (copper):
3 HOCl + 3 H3O+ + 3 e- ⇒ 3/2 Cl2(g) + 3 H2O
for an implied net reaction of:
3 HOCl + Al --> Al(OH)3 (s) + 3/2 Cl2 (g) Eo net = 3.93 V
This battery cell is theoretically capable of generating 3.93 volts.
Reference: see http://www.exo.net/~pauld/saltwater/ and http://sci-toys.com/scitoys/scitoys/echem/batteries/batterie... and also http://www.dtic.mil/dtic/tr/fulltext/u2/d019917.pdf
There are also many side reactions. For safety, however, it should be noted that in addition to the toxic/corrosive Chlorine gas, in the case of the
use of an excess of Aluminum, some explosive hydrogen gas can also be formed (in about a day) as the protective Al2O3 coating is attacked in a salt
solution permitting the reaction:
2 Al + 6 H2O --> 2 Al(OH)3 + 3 H2 (g)
[Edited on 28-8-2013 by AJKOER] |
I have more recently discovered that burning Aluminum foil in a perturbed flame (just knock the burner on your stove, once lit, slightly off center,
and a loud hotter flame is formed) till the Al is glowing red results in a form of weakened gamma Al2O3 covering the Aluminum that is functionally
more reactive. In the context of the current galvanic cell, after modest warming, the generation of Cl2 and the dissolution of the Aluminum commences.
I would also recommend a different path to HOCl as the presence of acetate in the cell after a few days apparently produces a nasty chloro-acetate.
Here is my new recommendation:
Mix NaClO with CaCl2, producing an equilibrium reaction:
CaCl2 + 2 NaClO = Ca(ClO)2 + 2 NaCl
which when shaken in a large vessel containing CO2 (from say, the action of NaHCO3 on vinegar, and the solution drained carefully leaving just the
heavy CO gas), a bright white precipitate of CaCO3 is formed along with Hypochlorous acid, moving the above reaction to the right:
Ca(ClO)2 + CO2 + H2O ---> CaCO3(s) + 2 HOCl
On cooling, the CaCO3 suspension collapses to a solid precipitate allowing the easy collection of the Hypochlorous acid.
[Edited on 21-9-2014 by AJKOER]
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Oxirane
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Chlorine cell electrolysis would be the ideal but the membrane may be very difficult to make working. There's been some discussion about this thing on
the forum before and many attempts to make chlorine cell with mixed and not very promising results. I am very interested to see if anyone has got a
working membrane cell that lasts reasonable long to produce useable amounts of chlorine. 
But just to say if one really needs those chemicals, register a company, I've had to work with many countries companies legal matters as foreign agent
and most places the registering procedure itself is very easy and cheap and after one has the company details, they can order just about anything that
has no special restrictions, and many cases even those bad-ones. This is superb for getting bulk stuff like many acids very cheap, less than a $ per
litre and bulk quantities since stuff like HCl, H2SO4, H2O2 are used in vast amounts for just about everything, including washing hardware equipment
where they're sold very handy 10, 25 and 50 liter canisters just right size for a decent hobbyist to last for a year or two. 
[Edited on 22-9-2014 by Oxirane]
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Dan Vizine
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Maybe we should have asked you in the first place, how much chlorine do you need?
Some of the ideas that have been suggested are experiments all by themselves. I try to avoid doing experiments before my chosen experiment even
starts. Any starting material which is to be made should be done with as little equipment, experimental time, procurement time as possible.
So let's look at your options for doing this...
a) Electrolysis - an experiment in itself
b) NaOCl + acid - out of consideration
c) Any Mn-based reaction - out of consideration
c) TCCA - Ideal if you have a source, subject to: how conc. does the HCl need to be? Can you get the HCl?
d) CuCl2 - Usually accessible, simple
Not surprisingly, pyrolysis or c) seem to be the most practical routes. You will probably have to invest way too much work if you choose electrolysis.
IMHO electrolysis usually seems at first glance to be a better route than it actually is because of the experimental conditions and support equipment
it takes to make it all work. If you have this equipment already, well, maybe. But I'd still look for a simpler way.
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Oxirane
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Indeed, building an electrolysis app is an enterprise on itself. One can make demonstrative buildups with batteries and lead pencils, but if you
really need to get some gas produced what you will need is power. PC power source could do it, but someone has even used welder transformer that can
output serious currents. The same way you need to get bigger wires and bigger electrodes and bigger cell, and so on, and soon you have found yourself
couple of hundred bucks poorer, with a bunch of hardware and lot of uncertainities and question marks, while you could have bought 20-30kg of chlorine
products otc. 
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CuReUS
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flakten
i recently saw a video about thermally cracking polystyrene to get styrene-http://www.youtube.com/watch?v=6tEs7P6UUVQ
that and your need for Cl2 gave me an idea.-why not burn PVC to get HCl http://www.fsrj.org/act/7_nenkai/02-1-IFSR/ISFR99/PP-20.pdf
and then do deacon's process (by oxidising the HCl produced with CuCL2 catalyst)-http://en.wikipedia.org/wiki/Deacon_process
this process is dangerous as burning PVC produces lots of other toxic gases other than HCl but since you have removed all traces of safety out of the
fume hood and given us liberty to suggest you any feasible process,i think its
worth a try.
if the worst comes to worst,atleast you will have a never ending source of HCl
[Edited on 23-9-2014 by CuReUS]
[Edited on 23-9-2014 by CuReUS]
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AJKOER
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| Quote: Originally posted by Dan Vizine | Maybe we should have asked you in the first place, how much chlorine do you need?
Some of the ideas that have been suggested are experiments all by themselves. I try to avoid doing experiments before my chosen experiment even
starts. Any starting material which is to be made should be done with as little equipment, experimental time, procurement time as possible.
So let's look at your options for doing this...
a) Electrolysis - an experiment in itself
b) NaOCl + acid - out of consideration
c) Any Mn-based reaction - out of consideration
c) TCCA - Ideal if you have a source, subject to: how conc. does the HCl need to be? Can you get the HCl?
d) CuCl2 - Usually accessible, simple
Not surprisingly, pyrolysis or c) seem to be the most practical routes....
|
I recall seeming a demo video on extracting MnO2 from a dry cell battery in minutes. As this likely can be performed without even a trip to the store,
this is certainly worthy of consideration. The opening thread states that dilute HCl is available to which I would add an excess of NaCl to increase
the activity coefficient of the dilute acid.
The pyrolysis (with the exception of the simple thermal heating of CuCl2) in the presence of oxygen is possibly the worst idea due to the extreme
toxicity issues of some products not to mention the smell, method of collection and purification issues. The burning of most plastics, for example,
produces NOx and HCN. Even if one collected these acid gases, they can combine with Cl2 to form even more extremely dangerous compounds. A very very
bad idea.
[Edited on 23-9-2014 by AJKOER]
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Oxirane
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You do not burn the PVC, you pyrolyze it. I've done polystyrene pyrolysis several times and it is quite as simple as shown in the video. I melted
styrofoam into acetone and then dumped the gelatine into a steel reactor and heated it with gas grill, acetone came over first and then the pyrolysis
started, I could get about 70% per mass of liquid hydrocarbons from styrofoam this way.
I was thinking, when carbon dioxide is passed through hot coal, it will form carbon monoxide. Could there be any reaction where 2 HCl could be cracked
into Cl2 and H2? These two gases are of course quite same as oxygen and hydrogen, and the reaction is highly exothermic, so another of these should be
captured off by some other compound to be discarded or further recovered.
Umm, yeah. I think I just tried to reinvent the wheel. What about just getting
some metal, and leading the HCl gas to it to form chlorides, and then just pyrolyze it to get pure chlorine gas? Iron will form dichloride which does
not decompose though, and trichloride will decompose with only single chlorine, forming dichloride. Copper would be, but it decomposes at about 1000C
and unless you have equipment for it..
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Dan Vizine
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| Quote: Originally posted by AJKOER | | Quote: Originally posted by Dan Vizine | Maybe we should have asked you in the first place, how much chlorine do you need?
Some of the ideas that have been suggested are experiments all by themselves. I try to avoid doing experiments before my chosen experiment even
starts. Any starting material which is to be made should be done with as little equipment, experimental time, procurement time as possible.
So let's look at your options for doing this...
a) Electrolysis - an experiment in itself
b) NaOCl + acid - out of consideration
c) Any Mn-based reaction - out of consideration
c) TCCA - Ideal if you have a source, subject to: how conc. does the HCl need to be? Can you get the HCl?
d) CuCl2 - Usually accessible, simple
Not surprisingly, pyrolysis or c) seem to be the most practical routes....
|
I recall seeming a demo video on extracting MnO2 from a dry cell battery in minutes. As this likely can be performed without even a trip to the store,
this is certainly worthy of consideration. The opening thread states that dilute HCl is available to which I would add an excess of NaCl to increase
the activity coefficient of the dilute acid.
The pyrolysis (with the exception of the simple thermal heating of CuCl2) in the presence of oxygen is possibly the worst idea due to the extreme
toxicity issues of some products not to mention the smell, method of collection and purification issues. The burning of most plastics, for example,
produces NOx and HCN. Even if one collected these acid gases, they can combine with Cl2 to form even more extremely dangerous compounds. A very very
bad idea.
[Edited on 23-9-2014 by AJKOER] |
The problem with this approach is that it violates the condition stated at the outset..."I have proper methods for handling the waste products from my
experiments but manganese compounds are problematic. I'm not going to pour manganese waste slurry into the drain. "
That's what I was referring to in my c) entry.
No Mn cmpds. is a tough constraint.
I'd make the location of a source of TCCA my top priority.
[Edited on 23-9-2014 by Dan Vizine]
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Metacelsus
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The issues with Mn waste can be avoided. It's possible to electrolytically regenerate manganese dioxide from manganese(ii) chloride produced from the
reaction with HCl. (look up electrolytic manganese dioxide)
This way, you will be indirectly generating chlorine by electrolysis, with a solid, and thus easy to work with, intermediate.
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