The Bucket Cell - Start to Finish

[WSM]

Wsm I believe it is worth the effort to run a test in the bucket cell for na-clo3

Arthur suggested something similar to me recently. I asked him if he is considering giving it a try.

 

If he does, I believe he'll post the results.

 

WSM

[WSM]

I'm looking forward to reworking pyrojig's bucket cell adaptor (BCA) and fitting it to run with larger, copper-filled titanium leads, so it will run cooler.

 

When it's ready, I'll get it to him so he can get back to running his cell.

 

WSM

[WSM]

I'm looking forward to reworking pyrojig's bucket cell adaptor (BCA) and fitting it to run with larger, copper-filled titanium leads, so it will run cooler.

When it's ready, I'll get it to him so he can get back to running his cell.

WSM

I'm heading off to the PGI Convention so work on pyrojig's bucket cell will have to wait till I get back.

 

I'll post the results when I make this happen.

 

WSM

[WSM]

I'm heading off to the PGI Convention so work on pyrojig's bucket cell will have to wait till I get back.

I'll post the results when I make this happen.

WSM

 

 

I got pyrojig's bucket cell lid done and ready to deliver. I'm certain he'll get it running before year's end, and hopefully report how things are going when he does.

 

WSM

[WSM]

I got pyrojig's bucket cell lid done and ready to deliver. I'm certain he'll get it running before year's end, and hopefully report how things are going when he does.

WSM

 

 

I got the equipment delivered and He'll probably get things going before the year is out. More electro-chemical fun to come... !

 

WSM

Edited September 26, 2021 by WSM

[WSM]

I'm halfway through rebuilding the electrodes for a friend's bucket cell. In the first version, the leads were too small and heating was a serious problem.

I've since remade the leads and upgraded from 6 mm OD titanium tubing to 3/8" (~9.5 mm) OD tubing, and plan to fill the space inside with 1/4" (6.35 mm) OD solid round copper rod. I find the solid copper conducts electricity so much better than filling the titanium tubing with solder, tin or almost any other metal; that the heating issues are reduced to easily manageable levels.

I've also enlarged the electrode size enough to give him a serious boost in reaction potential (more oxidizer production in shorter times). I expect he'll be happier with the whole setup and be able to make plenty of chlorate with his power setup.

He also mentioned his desire to build a second bucket cell with an LD anode for converting sodium chlorate to sodium perchlorate! It sounds like he has an exciting goal for his electrochemistry pursuits this year (I can't say I blame him ).

WSM

 

 

I received the electrodes from my friend to make perchlorate. The anode is a platinized titanium mesh roughly 1/2" x 4" long on a flat titanium strap. I think the maximum average current draw will be about 7.5 Amps DC, so a 0-10 Vdc 0-10 Adc power supply with constant current (CC) capability would work well for him. Even a small supply with 0-5 Vdc and 0-10 Adc output with CC capability would work admirably.

 

It won't make perchlorate fast, but with patience and careful use it can make a lot, over time!

 

Instead of using a bucket cell, I'll probably use a one gallon glass container for this perchlorate cell. These are easy to use indoors as there is virtually no chlorine production, just some ozone smell noticed emanating from the vent, plus likely hydrogen (which always needs to be carefully vented away to the atmosphere for safety).

 

WSM

[WSM]

I received the electrodes from my friend to make perchlorate. The anode is a platinized titanium mesh roughly 1/2" x 4" long on a flat titanium strap. I think the maximum average current draw will be about 7.5 Amps DC, so a 0-10 Vdc 0-10 Adc power supply with constant current (CC) capability would work well for him. Even a small supply with 0-5 Vdc and 0-10 Adc output with CC capability would work admirably.

It won't make perchlorate fast, but with patience and careful use it can make a lot, over time!

Instead of using a bucket cell, I'll probably use a one gallon glass container for this perchlorate cell. These are easy to use indoors as there is virtually no chlorine production, just some ozone smell noticed emanating from the vent, plus likely hydrogen (which always needs to be carefully vented away to the atmosphere for safety).

WSM

 

 

I see I neglected to mention that I'm making the small glass perchlorate cell for my friend. I have a small collection of perchlorate anodes set aside to use for my own projects later on.

 

I've postponed my own perchlorate experiments till I have a respectable amount of sodium chlorate made, hence my focus on that part of my research at the moment. More later...

 

WSM

[WSM]

I see no reason why a bucket cell wouldn't do a fine job of turning sodium chlorate to sodium perchlorate.

 

With the right setup, it could do a great job and probably last a long time.

 

WSM

[pyrojig]

I see no reason why a bucket cell wouldn't do a fine job of turning sodium chlorate to sodium perchlorate.

 

With the right setup, it could do a great job and probably last a long time.

 

WSM

Probably will make a huge amount of product beyond expectations and a small cell may be best to get the process learned and dialed in. There is an enormous amount of salt in a NA sys that stays in solution.. I'd probably go broke buying pallets of salt 😜 Edited October 29, 2021 by pyrojig

[pyrojig]

But I'd give it a whirl Edited October 29, 2021 by pyrojig

[Arthur]

My initial "back of fag packet" calculations were that a 2 - 3 litre cell would satisfy my needs for ever.

 

Maybe a 500ml cell would be good for test runs. All based on a 60a psu hopefully running cool at 25a for 160 hour per week with a little time off for any attention needed.

[WSM]

Probably will make a huge amount of product beyond expectations and a small cell may be best to get the process learned and dialed in. There is an enormous amount of salt in a NA sys that stays in solution.. I'd probably go broke buying pallets of salt

 

 

Remember, the sodium chloride solution left in a sodium chlorate cell, gets recycled into the follow up runs of the cell. The sodium chlorate crystals harvested from the chlorate cell are used to make the electrolyte for the sodium perchlorate cell.

 

By dropping out a portion of the sodium chlorate crystals, the remaining chlorate in the electrolyte is recycled to the next run of the sodium chlorate cell with added sodium chloride, which will produce more chlorate in a shorter time than the initial run because the "recharged" electrolyte has a head start with existing precursor ions, rather than starting from scratch with simple sodium chloride solution.

 

In the interest of preserving the perchlorate anodes, I only run the cell till the chlorate level drops off. This gives a fairly concentrated sodium perchlorate solution with an unknown but substantial sodium chlorate residue. I also run the perchlorate cell at lower voltages than commercial systems so the anode is not as stressed and prone to break down, as when trying to run them as harshly as chlorate anodes are typically run. I chose this method after hearing of other amateur electrochemists having their expensive and hard to obtain platinum and lead dioxide anodes break down when running them. I supposed they ran their cells with higher voltages and that was the cause of their woes (and why I approached the effort with my system powered under constant current conditions and lower voltages, give or take 4.0 Vdc rather than 6+ Vdc).

 

After the perchlorate cell was run to "calculated completion", my next step was to destroy the chlorate residue in my sodium perchlorate solution by treating the solution with sulfur dioxide gas.

 

The simplest method to do this is to treat the perchlorate solution with sodium metabisulfite solution, slowly and deep under the surface of the sodium perchlorate solution. I learned that this was necessary because dropping the metabisulfite on the surface of the perchlorate solution caused the SO₂ gas to "flash off" and disperse into the air rather than react with the chlorates within the perchlorate solution. I believe the "head pressure" of the solution plus the slow rate of injection kept the reactants within the solution, saving me from getting blasted by the noxious fumes otherwise experienced.

 

With the metabisulfite slowly flowing into the lower level of the perchlorate solution, little or no gas appears to form and the sulfur dioxide does its work of destroying the chlorate and leaving the perchlorate unaffected.

 

After the chlorate is removed from the perchlorate solution, the potassium chloride solution is added all at once, causing the fine white potassium perchlorate powder (very fine crystals, actually) to instantly drop out of solution. All the residual sodium salts remain dissolved and the newly formed potassium perchlorate is then filtered off and the purification of it is started (removing any residual sodium contaminants by careful rinsing with deionized water). Once the potassium perchlorate is rendered sodium-free, it is dried and stored for later use.

 

It's my contention that if careful and thorough purification of the sodium chloride and potassium chloride solutions are done before using them in our processes, we can achieve final products equal to, or better than, commercial potassium chlorates or perchlorates.

 

This is within our grasp if we take the necessary steps to accomplish it.

 

Why not? We're already bothering to make our own oxidizer salts, so why not take the extra steps to make them even better (and safer!)?

 

WSM

Edited October 30, 2021 by WSM

[Arthur]

With care the only material consumed is sodium chloride -what's not used should be recycled. and potassium chloride again what's not used remains for reuse next time.

 

The skill comes with fractional crystalisation of the product liquor to achieve a good separation of Ksalt product from the recyclable remainder.

[pyrojig]

Reply to wsm's quote:

 

( After the chlorate is removed from the perchlorate solution, the potassium perchlorate solution🧐 is added all at once, causing the fine white potassium perchlorate powder (very fine crystals, actually) to instantly drop out of solution)

 

I believe you meant potassium chloride solution is added all at once... Not potassium perchlorate solution...just for your readers to not get confused

Reply to wsm's quote:

 

( After the chlorate is removed from the perchlorate solution, the potassium perchlorate solution🧐 is added all at once, causing the fine white potassium perchlorate powder (very fine crystals, actually) to instantly drop out of solution)

 

 

 

I believe you meant potassium chloride solution is added all at once... Not potassium perchlorate solution...just for your readers to not get confused.

 

Very good points on purity , and I like efficiency not wasting materials . It feels like a shame to waste sodium chlorate to metabisfate cleaning, but the losses are minimal and the process is absolutely necessary.

 

BTW my constant current power supply came in the mail!! Can't wait to get time to set up some equipment and start some test runs on the system. Just need to get started purification of the NA salts..need some stock for perch later.

Edited October 30, 2021 by pyrojig

[WSM]

With care the only material consumed is sodium chloride -what's not used should be recycled. and potassium chloride again what's not used remains for reuse next time.

The skill comes with fractional crystalisation of the product liquor to achieve a good separation of Ksalt product from the recyclable remainder.

 

 

I fear a lot of precious material would be wasted in the pursuit of that skill. I like the simplicity of separate steps in the process.

 

WSM

[WSM]

Reply to wsm's quote:

I believe you meant potassium chloride solution is added all at once... Not potassium perchlorate solution...just for your readers to not get confused

Reply to wsm's quote:

( After the chlorate is removed from the perchlorate solution, the potassium perchlorate solution is added all at once, causing the fine white potassium perchlorate powder (very fine crystals, actually) to instantly drop out of solution)

I believe you meant potassium chloride solution is added all at once... Not potassium perchlorate solution...just for your readers to not get confused.

Very good points on purity , and I like efficiency not wasting materials . It feels like a shame to waste sodium chlorate to metabisfate cleaning, but the losses are minimal and the process is absolutely necessary.

BTW my constant current power supply came in the mail!! Can't wait to get time to set up some equipment and start some test runs on the system. Just need to get started purification of the NA salts..need some stock for perch later.

 

 

Good catch. Thanks for bringing it to my attention.

 

WSM

Edited October 30, 2021 by WSM

[WSM]

I fear a lot of precious material would be wasted in the pursuit of that skill. I like the simplicity of separate steps in the process.

WSM

 

 

I like the simplicity AND CONTROL of separate steps in the process.

 

It would be nice to have a quick system (especially in an industrial setting), but we have the luxury of time as amateurs and the benefit of separating the steps includes various purification steps we can use that help yield a superior final product.

 

WSM

[WSM]

Probably will make a huge amount of product beyond expectations and a small cell may be best to get the process learned and dialed in. There is an enormous amount of salt in a NA sys that stays in solution.. I'd probably go broke buying pallets of salt

 

Not really. In a sodium chlorate cell you can use the unharvested chlorate (with all the various precursor salts) to do the next run of chlorate (after re-charging the electrolyte with more sodium chloride).

 

For the perchlorate cell, the left over chlorate in the electrolyte is chalked up to "acceptable losses" when it's neutralized prior to adding potassium chloride solution in converting sodium perchlorate to potassium perchlorate.

 

I suppose it's all theory until the practical experience is gained .

 

WSM

[WSM]

Not really. In a sodium chlorate cell you can use the unharvested chlorate (with all the various precursor salts) to do the next run of chlorate (after re-charging the electrolyte)

WSM

 

 

Running the sodium chlorate cell at 40^o-50^oC, and then harvesting NaClO₃ crystals at 0^oC, I realized that I got perhaps 10% of the sodium chlorate out of the electrolyte.

 

The remaining chlorate isn't wasted; the used electrolyte can then be recharged with more NaCl and run again, now with greater efficiency since all the precursors and left-over chlorate are still there and a lot of energy isn't wasted making them as in the initial run! So things will go faster and with greater yields in subsequent runs.

 

WSM

[WSM]

Reply to wsm's quote:

( After the chlorate is removed from the perchlorate solution, the potassium perchlorate solution is added all at once, causing the fine white potassium perchlorate powder (very fine crystals, actually) to instantly drop out of solution)

I believe you meant potassium chloride solution is added all at once... Not potassium perchlorate solution...just for your readers to not get confused

Reply to wsm's quote:

( After the chlorate is removed from the perchlorate solution, the potassium perchlorate solution is added all at once, causing the fine white potassium perchlorate powder (very fine crystals, actually) to instantly drop out of solution)

I believe you meant potassium chloride solution is added all at once... Not potassium perchlorate solution...just for your readers to not get confused.

Very good points on purity , and I like efficiency not wasting materials . It feels like a shame to waste sodium chlorate to metabisfate cleaning, but the losses are minimal and the process is absolutely necessary.

BTW my constant current power supply came in the mail!! Can't wait to get time to set up some equipment and start some test runs on the system. Just need to get started purification of the NA salts..need some stock for perch later.

 

 

Yup! I sure bone-headed that one. Thankfully, pyrojig caught my error and realized what I meant to say. I need to carefully read through my writing before hitting the "Send" button (or at least read it after and use the "Edit" feature).

 

Thanks to friends who take the time to correct our missteps and clarify our message!

 

WSM

[WSM]

I realize it's been over nine years since Swede has posted anything. That's too bad, he was a prolific researcher and documented his thoughts and projects well. We miss him and his offerings which supported our own efforts in electrochemistry.

 

We wish him well in his current pursuits and hope he is well.

 

WSM

Edited February 27, 2022 by WSM

[WSM]

In my research, I sourced and obtained a nice sized piece of 3/4" thick PVC plate. I'm considering making a few BCA's (Bucket Cell Adaptors) to try, similar to what Swede did prior to starting this thread so many years ago.

 

My first thought is to make them round, rather than square the way Swede did, so they'll fit better on many of the bucket lids available to us and offer more space for extra fittings, et cetera, as we develop our systems. I prefer to use titanium round tubes or rods to make my electrode leads to help prevent the salt creep that tends to eat at our copper lead wires.

 

Thanks to Swede's innovations (see his descriptions in the blog section), I switched to using round CP titanium tubing for my electrode leads which are held in PVDF (Kynar) fittings for a perfect seal which helps solve that problem. The 3/4" thick PVC is machinable, compatible with our chlor-alkali cells and it's fairly easy to use machining taps to add tapered pipe threads through the BCA for plumbing fittings into and out of the bucket cells.

 

I need to make at least one prototype BCA and try it out in a working cell.

 

I plan to post photos here of my efforts as I progress. More to come...

 

WSM

Edited March 28, 2022 by WSM

[WSM]

In my research, I sourced and obtained a nice sized piece of 3/4" thick PVC plate. I'm considering making a few BCA's (Bucket Cell Adaptors) to try, similar to what Swede did prior to starting this thread so many years ago.

My first thought is to make them round, rather than square the way Swede did, so they'll fit better on many of the bucket lids available to us and offer more space for extra fittings, et cetera, as we develop our systems. I prefer to use titanium round tubes or rods to make my electrode leads to help prevent the salt creep that tends to eat at our copper lead wires.

Thanks to Swede's innovations (see his descriptions in the blog section), I switched to using round CP titanium tubing for my electrode leads which are held in PVDF (Kynar) fittings for a perfect seal which helps solve that problem. The 3/4" thick PVC is machinable, compatible with our chlor-alkali cells and it's fairly easy to use machining taps to add tapered pipe threads through the BCA for plumbing fittings into and out of the bucket cells.

I need to make at least one prototype BCA and try it out in a working cell.

I plan to post photos here of my efforts as I progress. More to come...

WSM

 

 

Recently, I dug out my table saw and the large piece of 3/4" thick grey PVC plate (12" x 48"), and cut four 6" x 6" square pieces. I'm disappointed that they weren't perfectly square (more trapezoidal) but they ought to work anyway, for prototype BCA's.

 

The practical reason to cut the bucket cell adaptors square rather than round is to avoid wasting the material outside of a circular shape.

 

My next step will be to use a router to round the edges not facing the bucket lid. The rounded chamfer will help me avoid cutting my hand while handling the hard plastic material, as well as remove confusion as to the orientation of the BCA on the cell lid.

 

Once I complete the basic shape of the BCA, I need to select a bucket lid to attach it to and then plan the layout. To avoid contamination problems, plus simplify compatibility issues, my thought is to mount the BCA on the underside of the lid, with stainless steel hardware coming through the lid into the BCA. I think 1/4-20 hex bolts with fender washers (all 300 series stainless steel) should work since they'll be outside the cell, with none of it exposed to the corrosive environment inside the cell.

 

The plan is to cut a hole in the bucket lid smaller than the BCA, leaving a flange for connecting and sealing the two parts into a single, complete unit.

 

I debated whether or not to use a Viton gasket between the BCA and the bucket lid, but feel the simple solution is to use silicone bathroom caulk between the BCA and bucket lid when screwing them together. The silicone sealer doesn't need to perfectly adhere to all the materials to make a good seal, plus it is easy to remove and replace, if and when needed.

 

I was originally thinking of using bolts in the four corners of the BCA, but perhaps eight bolts would make a better seal (four corners plus one bolt each between them, on the straight sides).

 

If I decide I like the plan, I'll have to make a drill guide to keep the hole pattern uniform for matching the hole pattern on the BCA and bucket lid.

 

More to come...

 

WSM

Edited May 1, 2022 by WSM

[WSM]

Recently, I dug out my table saw and the large piece of 3/4" thick grey PVC plate (12" x 48"), and cut four 6" x 6" square pieces. I'm disappointed that they weren't perfectly square (more trapezoidal) but they ought to work anyway, for prototype BCA's.

 

 

I will try this size and see if it works. Another thought is if I find that I need more area for many more tapped holes (needed for extra equipment, such as sensors, access ports, et cetera), I may opt for an 8" x 8" BCA instead of the smaller prototypes I've already cut.

 

There are many options, and I won't limit my ability to explore them on this project .

 

WSM

[WSM]

I will try this size and see if it works. Another thought is if I find that I need more area for many more tapped holes (needed for extra equipment, such as sensors, access ports, et cetera), I may opt for an 8" x 8" BCA instead of the smaller prototypes I've already cut.

There are many options, and I won't limit my ability to explore them on this project .

WSM

 

 

In reality, an 8" BCA would have to be round to fit on a normal 5 gallon bucket lid, by my measurements.

 

WSM

 

Edit: A square 8" BCA would fit IF the corners were severely rounded, I imagine. We'll see if and when it appears necessary...

Edited May 4, 2022 by WSM