Building a small scale KCLO3/04 Cell

[AustralianPyromaniac]

Hey everyone, so basically I need some help with getting my first chlorate cell up and running as after a fair bit of research I still can't figure out a few things.

 

The details of my plan so far are that its going to be a 2.5L glass cell using an MMO Anode and a Ti Cathode links below. My first question is basically would these be suitable and if not, can anyone recommend an alternative. I know that these materials have been recommend but is there anything I need to know regarding quality thickness or anything else?

 

MMO Anode: http://www.ebay.com.au/itm/172354640140?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

 

Ti Cathode: http://www.ebay.com.au/itm/142198453856

 

My second question is what sort of current (Amps) would I require to run such a cell and does this change according to the proximity of the electrodes? Basically, if I get a certain power supply do I need to ensure that the electrode are set distance apart and adjust them or just set them up say 5cm apart and go for it?

 

Continuing on from my previous question I'm completely lost on the subject of powers supplies. I've heard that computer powers supply can be used but I would really appreciate it if someone could point me in the right direction regarding this and give me and idea of the Amps & Volts I should expect to require and the best way to get them computer power supply or otherwise. I'm savvy enough with electronics so thats not a problem.

 

Thanks in advance for the replies and I apologise for asking some questions that likely seem obvious to the more experiences users of this site as I simply haven't been able to find answers to them (Not for lack of trying).

 

P.S.

I think I should also mention that I live in Australia and have been having a lot of troubles with finding reasonable cheep anodes that are suitable for our purposes so thats why I'm using the recycled pool chlorinator one.

[greenlight]

There is a thread on here called making potassium per/chlorate that has loads of info but it is about 200+ pages long.

User WSMs blog also has alot of info.

 

This is where I get my electrode from for my cells. He sells the Ti and MMO anode and cathode together for $25 which is decent and they work well:

 

http://store.theamateurchemist.com/electrodes/

 

I have a perc cell that is 2.7 litres and I use a 5 volt 20 amp power supply with it but it requires a water bath to keep the temp down after it has been running a while.

Electrodes are 1 inch apart.

 

Chlorate cells are easy as you can see how far done they are because the product precipitates on the bottom of the cell.

2.5 litre cell with a 5 volt 20 amp supply and MMO anode and a Ti cathode and keep temp around 70 C using a water bath if needed and you should get heaps of chlorate.

I will try find my specs from my first chlorate cell if you would like

Good luck.

Edited April 15, 2017 by greenlight

[AustralianPyromaniac]

There is a thread on here called making potassium per/chlorate that has loads of info but it is about 200+ pages long.

User WSMs blog also has alot of info.

 

This is where I get my electrode from for my cells. He sells the Ti and MMO anode and cathode together for $25 which is decent and they work well:

 

http://store.theamateurchemist.com/electrodes/

 

I have a perc cell that is 2.7 litres and I use a 5 volt 20 amp power supply with it but it requires a water bath to keep the temp down after it has been running a while.

Electrodes are 1 inch apart.

 

Chlorate cells are easy as you can see how far done they are because the product precipitates on the bottom of the cell.

2.5 litre cell with a 5 volt 20 amp supply and MMO anode and a Ti cathode and keep temp around 70 C using a water bath if needed and you should get heaps of chlorate.

I will try find my specs from my first chlorate cell if you would like

Good luck.

Thanks for the reply I really appreciate it. I just purchased the electrodes you recommended but just need one thing cleared up. You state that I should use a 5v 20A power supply but I'm stil confused about what the best power supply would be? And plans you would be greatly appreciated as I'm certainly trying to get as much info as possible to do things safly and hopefully efficiently.

 

EDIT: Would something like this be appropriate?

https://www.ebay.com.au/itm/152147392473

Edited April 15, 2017 by AustralianPyromaniac

[greenlight]

Yes I use a similar power supply to the one you linked.

You just have to cut an old cord off a broken appliance and connect the positive, negative and ground to the unit so you can plug it into the wall socket.

 

I will find all the specs for you for my chlorate cell when I get home tonight.

[greenlight]

First chlorate cell:

 

Size: 900ml

Power supply: 5 volt 20 amp power unit

Anode: MMO

Cathode: Titanium mesh

Electrode spacing: 30mm apart

Run time: 100 hours

Yeild: 320 grams potassium chlorate

 

Current per/chlorate cell

 

Size: 2.6 litres

Power supply: 5 volt 20 amp

Anode: MMO or Pt

Cathode: Titanium

Electrode spacing: 45mm

Run time: 100 hrs..(awaiting shunt for ammeter)

Yeild: Not finished

 

Sits at 70.C in a water bath when on so maybe space electrodes slightly further apart next time.

[Arthur]

You really should read the existing topic, there is a lot of expert discussion there and a lot of construction details. When you have read all 240 pages most of your questions will be answered, you will have learned of and from the mistakes of others and able to proceed with your cell with confidence, then you should write and post your experimental details and results. Once you have read up on all the work so far by others, members will be more willing to spend time discussing the finer points of your cell with you.

 

There are numerous Youtube videos available about how to modify an ATX computer power supply to get a controlled voltage output, otherwise ebay will offer you all sorts of power supplies. I'd suggest that 20A is a good start and 50A is a big amateur production unit.

[AustralianPyromaniac]

 

Thank you very much! Just ordered that power supply and the wireing looks very simple and a lot less scary than the alternative of amongst other things wireing microwave transforms together!

 

I will adjust those electrodes to reduce the heat output and hopefully get it down to a temperature manageable without a water bath and when I'm complete post a few photos on this thread.

 

You really should read the existing topic, there is a lot of expert discussion there and a lot of construction details. When you have read all 240 pages most of your questions will be answered, you will have learned of and from the mistakes of others and able to proceed with your cell with confidence, then you should write and post your experimental details and results. Once you have read up on all the work so far by others, members will be more willing to spend time discussing the finer points of your cell with you.

 

There are numerous Youtube videos available about how to modify an ATX computer power supply to get a controlled voltage output, otherwise ebay will offer you all sorts of power supplies. I'd suggest that 20A is a good start and 50A is a big amateur production unit.

I appreciate your comments and I do understand where your coming from. But I think it's important to consider that ok... I haven't read through the whole thread on perc manufacture I have read a bit and am planning to read more. The main reason of starting this new thread is simply my inability to find this information using YouTube google and the APC and even if I had read through the whole thread I would bet that the information I got from this thread wouldn't have been available certainly not in as much detaile in the perc thread.

[WSM]

My first few successful cells were powered by a similar supply (5Vdc 30 Amps) and they typically ran at about 45^oC in a 1 gallon glass jar (maybe 3 liters full). Check out my blog, Homegrown Oxidizers Part One for more details.

 

If you have questions, feel free to ask.

 

WSM

Edited April 17, 2017 by WSM

[Arthur]

The important detail is that every amateur cell is different, so it's impossible to give detailed advice that's accurately suited to your cell. Some times you need to understand how "best practice" and "best amateur skills" actually apply to your own cell -especially in terms of current, volume and temperature.

[AustralianPyromaniac]

My first few successful cells were powered by a similar supply (5Vdc 30 Amps) and they typically ran at about 45^oC in a 1 gallon glass jar (maybe 3 liters full). Check out my blog, Homegrown Oxidizers Part One for more details.

 

If you have questions, feel free to ask.

 

WSM

Thanks I appreciate having your experience at hand if I need it! Just read your blog and I think its very well written, very informative. I was a little confused about how you mentioned determining the finishing point of the electrolysis though. At first you mentioned just observing the current flow to determine the end point of the reaction and then mentioned using decity measurements for the same thing. Can both of these methods be used and is the current draw method reliable enough as it's certainly much easier?

 

EDIT: Accidental double post.

Edited April 18, 2017 by AustralianPyromaniac

[WSM]

Thanks I appreciate having your experience at hand if I need it! Just read your blog and I think its very well written, very informative. I was a little confused about how you mentioned determining the finishing point of the electrolysis though. At first you mentioned just observing the current flow to determine the end point of the reaction and then mentioned using decity measurements for the same thing. Can both of these methods be used and is the current draw method reliable enough as it's certainly much easier?

EDIT: Accidental double post.

When I first started (electrolyzing KCl), I only watched the current draw (I didn't have a decent hydrometer), but now I'd definitely go that way.

 

For the potassium chlorate cell, it's a good way to monitor the progress of the run since the end product precipitates out of the solution, and the specific gravity changes reliably as this happens.

 

Lacking the hydrometer, watching the current provides an excellent "educated guess".

 

WSM

Edited April 19, 2017 by WSM

[WSM]

I should mention, using a hydrometer with a sodium chlorate cell is not as effective as with a potassium chlorate cell. The sodium chlorate is more soluble than the chloride it's made from, so everything stays in solution and the specific gravity of the electrolyte changes much more subtly.

 

WSM

[AustralianPyromaniac]

Hello again, I put this project on hold for a while but its finally up and running producing chlorate as I write this. I resurrected this thread to give some feedback ask a few more questions that after reading the "Making potassium (per) chlorate" still haven't been answered.

 

Firstly a warning, I purchased a 20A LED power supply and tried to use it, but within 5 minutes it overheated and died even with a cooling fan blowing on it. So my advice to anyone building a cell is, do not use and LED power supply. Other than that I had no problems and ended up just using an ATX power supply which is working splendidly without any overheating.

 

Now onto my questions.

 

Firstly, when running the cell what is the ideal temperature to avoid hypochlorite production; I know I read it but it escapes my mind and i cant find it with a google search.

 

Secondly, when using an MMO anode Ti cathode is it bad for the electrodes just to run the cell splitting H₂O after the end point is reached to ensure all KCl is consumed or should I stop before that to increase the longevity of the cell?

 

Thanks, heaps.

[Doloy]

 

Hello again, I put this project on hold for a while but its finally up and running producing chlorate as I write this. I resurrected this thread to give some feedback ask a few more questions that after reading the "Making potassium (per) chlorate" still haven't been answered.

 

Firstly a warning, I purchased a 20A LED power supply and tried to use it, but within 5 minutes it overheated and died even with a cooling fan blowing on it. So my advice to anyone building a cell is, do not use and LED power supply. Other than that I had no problems and ended up just using an ATX power supply which is working splendidly without any overheating.

 

Now onto my questions.

 

Firstly, when running the cell what is the ideal temperature to avoid hypochlorite production; I know I read it but it escapes my mind and i cant find it with a google search.

 

Secondly, when using an MMO anode Ti cathode is it bad for the electrodes just to run the cell splitting H₂O after the end point is reached to ensure all KCl is consumed or should I stop before that to increase the longevity of the cell?

 

Thanks, heaps.

 

According to what I read, to avoid the formation of hypochlorite the solution should be hot, but under 70*C. My guess would be 50 to 60 *C.

 

I would advise you not to continue the electrolysis after the end point. Some of the dissolved chlorate will start oxidizing to perchlorate and it will most likely destroy your MMO anode because of the extreme oxidizing conditions.

[AustralianPyromaniac]

According to what I read, to avoid the formation of hypochlorite the solution should be hot, but under 70*C. My guess would be 50 to 60 *C.

 

I would advise you not to continue the electrolysis after the end point. Some of the dissolved chlorate will start oxidizing to perchlorate and it will most likely destroy your MMO anode because of the extreme oxidizing conditions.

 

Thanks for that reply. My understanding though is that due to the oxygen potential of MMO it is impossible to produce any perc but not 100% sure. Other than this do you know of any further problems associated with this?

 

Also, welcome to the forums!

Edited June 12, 2017 by AustralianPyromaniac

[MrB]

Firstly a warning, I purchased a 20A LED power supply and tried to use it, but within 5 minutes it overheated and died even with a cooling fan blowing on it. So my advice to anyone building a cell is, do not use and LED power supply.

 

Seams weird. Of course, every manufacturer has a bad unit now and then, but i've loaded mine with 16A for days, no issues, as well as know quite a few "others" using these PSU's for similar loads, and some specifically for cells.

 

Did you verify that your current was within spec? Over-voltage, or over-current, could easily fry things.

[AustralianPyromaniac]

 

Seams weird. Of course, every manufacturer has a bad unit now and then, but i've loaded mine with 16A for days, no issues, as well as know quite a few "others" using these PSU's for similar loads, and some specifically for cells.

 

Did you verify that your current was within spec? Over-voltage, or over-current, could easily fry things.

Yes, I used my multimeter and it was only drawing 12A according to my calculations. I even sent the first unit I received back to the seller to get a new one and the second one had the same issue as the first.

[MrB]

Weird. Voltage?

 

Perhaps the seller got his from a bad source or something. But that shows you what to expect, i suppose. Cheap stuff might have varying quality. Who know.

Worth taking in to account when recommending these PSU's. Thanks for the heads up.

[Doloy]

 

Thanks for that reply. My understanding though is that due to the oxygen potential of MMO it is impossible to produce any perc but not 100% sure. Other than this do you know of any further problems associated with this?

 

Also, welcome out itto the forums!

You might be right, but if I were you I'd rather not risk it. Better waste some KCl in my opinion. Also, in the past I've made small quantities of chlorate and perchlorate, the only thing I would add is that if you plan to make perchlorates in the futur I suggest using a lead dioxide anode. In the past I used a platinum anode for perchlorates, It worked wonderfully the first time and I ended up with about 200 grams of perchlorate, but then the anode just stopped working after a few more runs. There was a non-conductive white coating on it. The current density might also be good to check if you want to make sure your anode last long (usually 0,3A/cm2 for MMO).

[AustralianPyromaniac]

Weird. Voltage?

Perhaps the seller got his from a bad source or something. But that shows you what to expect, i suppose. Cheap stuff might have varying quality. Who know.

Worth taking in to account when recommending these PSU's. Thanks for the heads up.

My understanding is that these kind of supplies provide a constant voltage of 5v with varying current depending on the load. In this case the load was only drawing 12A at 4.7v as far as I remember but regardless of the load the PSU would still push 5v through it discounting the resistance of the solution. As such it would be impossible to "draw" more than 5v.

 

You might be right, but if I were you I'd rather not risk it. Better waste some KCl in my opinion. Also, in the past I've made small quantities of chlorate and perchlorate, the only thing I would add is that if you plan to make perchlorates in the futur I suggest using a lead dioxide anode. In the past I used a platinum anode for perchlorates, It worked wonderfully the first time and I ended up with about 200 grams of perchlorate, but then the anode just stopped working after a few more runs. There was a non-conductive white coating on it. The current density might also be good to check if you want to make sure your anode last long (usually 0,3A/cm2 for MMO).

Thanks for the heads, that build up may have been some sort of salt collecting on the anode? If you have the problem in future try soaking in 5:1 H2O:HCl this is what I use to clean the white buildup on my pool chlorinater which after a while becomes completely non coductive and stops producing chlorine works a charm!

 

I think I will try running the KCl down because it occurred to me that MMO pool chlorination units run with very low levels of NaCl and work with no problem for years and years on end though they don't have 50-60 c liquids as well.

 

As far as current levels I think I'm good I did all my calculations and I'm sending just about the right amount of current though them considering the size of the electrodes I'm using.

 

Thanks for all the replies I really do love the APC community!

[WSM]

So far as making hypochlorite, my chlorate cells always make hypochlorite (a first step in the electrochemical process of making chlorate).

 

I forgot to ask, are you trying to make sodium or potassium chlorate?

As your cell electrolyzes the chloride solution it forms hypochlorite, hypochlorous acid (chlorite) and chlorate. After the cell run, the "depleted" solution has all of them in it. My used electrolyte always smells of bleach. Handle it carefully and wear personal protective equipment, i.e., rubber or nitrile gloves, and keep it off your clothes.

WSM

Edited June 17, 2017 by WSM

[AustralianPyromaniac]

As far as making hypochlorite, my chlorate cells always make hypochlorite (the first step in making chlorate).

 

When your cell electrolyzes the chloride solution it forms hypochlorite, hypochlorous acid and chlorate. After the cell run, the "depleted" solution has all of them in it.

 

WSM

I understand that but I was under the impression that at below a certain temperature the hypochlorite reaction disproportionates the chlorate reaction and not chlorate at all is produced.

[Mumbles]

That's not really true. High heat drives the hypochlorite disproportionation (thus requiring smaller cells), and decreases the resistance of the solution. Hypochlorite disproportionates at basically all temperatures, but the higher the temp the faster it works. pH is also important to this process to prevent hypochlorite decomposition to non-chlorate species and non-chlorate electrolysis products.

[MrB]

My understanding is that these kind of supplies provide a constant voltage of 5v with varying current depending on the load. In this case the load was only drawing 12A at 4.7v as far as I remember but regardless of the load the PSU would still push 5v through it discounting the resistance of the solution. As such it would be impossible to "draw" more than 5v.

 

Nah... They are both adjustable, and easy to modify for different voltages. Which was why i asked. 4.7v doesn't really seam extreme, anyway, so i have no idea at this point. Seams mostly to be just bad luck. That seller might have had a bad batch of PSU's or something.

[Arthur]

Lots of cheap kit will produce full power BUT cannot handle the internal heat build up over time, then components or solder joints start to heat, stress and fail.

Edited June 14, 2017 by Arthur