The Bucket Cell - Start to Finish

[Arthur]

Perspex -one of the MethylMethacrylate polymers used for windows and aircraft canopies.

 

The relevance is that if you can describe your Bucket Cell Adaptor as an art piece rather than an engineering piece someone who makes and engraves trophies will have the tools to make your bucket cell adaptor plate out of your chosen plastic -PVC or cPVC in this case. Let's face it, few of us design a cell to mils.

 

Please be cautious with big cells. The conditions to make chlorate by electrolysis are favoured by warm conditions (ask Mumbles for the precise thermodynamics!) to get and keep a IBC size cell hot would take much too much current for a domestic supply and make a commercial amount of product and waste. One of the significant design elements of a cell is suiting the current to the cell size, current not used for electrolysis will create heat, that heat is lost through the cell walls and heat produced will match heat lost at a certain temperature rise above ambient.

 

Probably a reasonable top limit for a "home" cell is the amount of damage that a container failure would make -and what is acceptable. IMO the best uses for an IBC would be holding water at a site, and using one as a tray in which to contain the whole wet side of the process. Anyone doubting the risks associated with too big a plant should search youtube for "pepcon" or just consider the herbicidal effect of chlorate over a radius of 500ft if your cell leaks into the ground.

[MrB]

Please be cautious with big cells. The conditions to make chlorate by electrolysis are favoured by warm conditions (ask Mumbles for the precise thermodynamics!) to get and keep a IBC size cell hot would take much too much current for a domestic supply and make a commercial amount of product and waste. One of the significant design elements of a cell is suiting the current to the cell size, current not used for electrolysis will create heat, that heat is lost through the cell walls and heat produced will match heat lost at a certain temperature rise above ambient.

 

I was mostly jesting, but for the sake of argument... I have been toying with a plan of a "IBC" sized cell, with a two compartment design. Using an actual IBC for this design, would be favorable, since it makes hooking things to it, real easy, with it's flat sides, and the metal reinforcements allow for sturdy constructions. A "fairly small" heating mat, and insulation will take care of keeping the system temperature where it "needs" to be, and the smaller reaction "cell" piggybacks of the side of it, getting feed from the top, and having a "magic bean" stirrer in the bottom to create circulation and push the reacted fluid, and solids back in to the larger volume, the IBC it self. Hell, if there is an issue with keeping the temperature up, those stirrers can be bought as hotplate - with stirrer. Buy a fancy one, and have it temperature controlled. Tape the probe to the IBC, inside the insulation.

 

And of course. Care should always be taken to avoid spills. It would suck to run one of these in your backyard for a few years, find out that you have to move for personal reasons, and come to find out that nothing grows in the backyard anymore.

[Arthur]

Just random numbers!

 

a 5v psu outputting 50amps that's 250 watts, probably draws 500w from the mains.

a 5v psu outbutting 100amps .......500 watts, probably consumes 750watts.

 

When does it become

1/ too expensive to run -electricity costs money

2/ too productive to run - after the first or second ton of chlorate per week???

3/ too time demanding to run, -it's only part of your life.

 

Personally I think that say 25 amps running 24/7 would produce a reasonable amount for home production, purification and use. What is the appropriate rate of conversion in terms of realistic yield in kilos per amphour? Would I be satisfied at 1kilo a week, probably. Would I want 100kilos/week absolutely NOT.

[MrB]

a 5v psu outputting 50amps that's 250 watts, probably draws 500w from the mains.

a 5v psu outbutting 100amps .......500 watts, probably consumes 750watts.

 

Not sure why your examples both have 250w as "waste heat" but that puts you on 50 & 75% efficiency. A modern switched power-supply generally speaking sits around 80% efficiency, and "great" power-supplies can be over 97%.(A cheap-o one like the mean well RSP-750-5 is rated at "up to" 82% efficiency.) They don't provide any info on efficiency@power output, at least not in the manual, but it's not going to be dropping of as far down as to 50% outside very low loads, and looking at around 50-95% load, you should still be in the 80% efficiency range.

I would make it a habit to verify that you aren't actually running at 100% output from the PSU, regardless of what PSU one decides to use.

 

When does it become

1/ too expensive to run -electricity costs money

2/ too productive to run - after the first or second ton of chlorate per week???

3/ too time demanding to run, -it's only part of your life.

 

Personally I think that say 25 amps running 24/7 would produce a reasonable amount for home production, purification and use. What is the appropriate rate of conversion in terms of realistic yield in kilos per amphour? Would I be satisfied at 1kilo a week, probably. Would I want 100kilos/week absolutely NOT.

 

But why would you run it 24/7, week after week, if you produce the 5 kilos you need for the next 6 months in one go?

It doesn't really matter if it takes 5 minutes, or 5 weeks, the idea is to simplify the process. If i can cut down on hassle, by going larger, i may very well. At some point you are breaking even. 5 runs that produce 1 kilo each, or one run that produces 5 kilos, where both setups need the same amount of time to produce the 5 kilos, means you are pretty much spending a little more on the hardware, with virtually no gains. But if you can cut back on the amount of work you have to put in to it, then it might be worth it.

[WSM]

Someone (I think it was Arthur, several years ago) once mentioned setting up a photovoltaic array to power a cell. Most of us wrote off the suggestion as impractical and too expensive.

 

The price and availability of solar panels are becoming more obtainable as time goes on, and I've been revisiting the idea.

 

First of all, solar panels alone won't work because they only generate voltage during daylight hours; BUT, with a battery backup system plus an intelligent controller, this drawback can be overcome. Fortunately, these are also becoming more available and affordable. The batteries are probably the priciest part of the equation, but that can be overcome as well.

 

The best approach may be to build a shed to house the whole setup and use the photovoltaic array for a somewhat oversized roof (angled to suit the maximum sun exposure). I envision building an electrochemistry shed, which (depending on the scope of the project) could be self sustaining for power.

 

The first part is to design it for adequate power generation during the shortest days of the year, plus enough extra to account for less than optimal solar conditions (cloudy days). This means more panels than needed for "average" consumption days, and the rest of the system designed to match. Too much electrical power is never a problem; we always find ways to use more, but too little electricity IS a problem, so always go bigger (plan for extra power for the future).

 

What's needed is a battery backup system capable of lasting long enough to endure the longest period of darkness anticipated in a normal year plus at least 10% more (remember about cloudy days).

 

A good power inverter is also required unless the whole system is built from scratch to deliver only 4Vdc for the chlorate or perchlorate cells (impractical).

 

The idea of creating a solar power system sounds ridiculous, if it's only intended for hobby uses; but if it's set up for supplying supplemental power for the household (especially when keeping it separate from the power grid, simplifying the whole setup), the idea of being self sufficient for at least part of your home's power consumption is a lot more attractive.

 

We'll explore this further...

 

WSM

Edited September 22, 2017 by WSM

[PeteyPyro]

Perchlorate and chlorates are still available in the USA, however, they might eventually be banned (CPSC?). On that day, I might be utilizing the existing photovoltaic gear that is currently a power backup for the well pump. (Came in handy for Hurricane Irma last week, when there was no power for 6 days). Some lead dioxide and MMO/Ti electrodes may be in my future✴ The solar panels, batteries, charge controller, and inverter should be of sufficient capacity to run the chlorate cell's PSU, day and night, at a high enough current for proper efficiency and operating temperature and to prevent unwanted crystallization from night time cooling. (Dog not included)

[Arthur]

The problem with solar power is that even in the sunnyest places there will be no more than 8 hours of power sunlight in a typical day, AND chlorate and perc electrodes don't stand leaving in the liquid when there is no power to them

 

The basic idea for solar power came from an old plant I once had to electrolyticaly recover silver from photo fixer.

 

The cell was above the reservoir tank and had three connections,

one the bottom drain simply let the liquid drain back into the reservoir tank to protect the electrodes when the power went off,

the second was a large overflow so that the cell couldn't possibly overflow

the third was the pumped feed from the reservoir to the cell using a magnetically coupled chemically resistant pump (Iwaki again off an old photo processor)

 

The big challenge for this process will be controlling the temperature of the cell -it must be warm to work while letting the solution off the electrodes when the solar is off.

 

Adding batteries and an inverter adds more cost and the limited life of cycled batteries (say 1000 cycles) adds more cost.

 

Heat is generated in the cell by current lost to electrolysis, in a simple cell the heat goes out the cell walls and top and equilibrium is achieved when heat generated equals heat loss at a certain temperature. When heat is lost by flow to the holding reservoir as well then there will be more variables to determine the current needed to maintain adequate cell temperature.

 

I can see that two cells in series (say 10v) run off a 500w solar array and manually connected every morning and disconnected every evening would be an off grid start up project, But it's manual. A small cell could be raised on jack screws by first solar of the day .......

[MrB]

I can see that two cells in series (say 10v) run off a 500w solar array and manually connected every morning and disconnected every evening would be an off grid start up project,

 

Well... If we ignore weather, transmission, and transformer losses, a 500w system would be able to run a 16.6A 10v setup, 24/7. I think i'd rather aim at a single 5v cell, it would make it possible to run in the neighborhood of 30A through the cell.

Practically we have a bunch of losses, so, perhaps aim for a 20A cell, (100w. Means you'd have 200w / hour unused, to cover losses. not entirely sure that is reasonable. The array provides charging voltage, so no losses from the array "to" the battery bank. But then there is the invertor, to go from the battery-bank, to the cell PSU, which in turn has it's own transformer, and a second set of losses. I wonder if there is a 12-14.4v buck convertor that will output "cell voltage", preferably slightly adjustable for fine tuning. Skipping the invertor would remove one set of losses.) and go grab a bunch of batteries from old trucks with sleeper cabs. Especially if these trucks have been used in cold weather, they swap the batteries "early", and there are lots of life left in them. The fact that they are 200-300A and 12v doesn't hurt either. 3 or 4 should be just enough to get through the night, so 5-6, would make sure you never have to deplete them entirely, and give you some small reserve for when the weather sucks some day. Every now and then you'd have to let the system "charge up" fully, if you have a lot of crappy weather, something like not using it at all the day you recover the product from the cell, or similar.

 

Makes a lot more sense to me, then hooking a solar system to the house, and try to offset costs on power bills that way. (Here in Sweden you are forced to use a metering-unit to keep track of how much electricity you produced, so that a energy company can "buy" it from you, and then sell it back to you, just so that the government gets their taxes... But if it's not "household power" you can skirt the rules.)

[WSM]

Well... If we ignore weather, transmission, and transformer losses, a 500w system would be able to run a 16.6A 10v setup, 24/7. I think i'd rather aim at a single 5v cell, it would make it possible to run in the neighborhood of 30A through the cell.

Practically we have a bunch of losses, so, perhaps aim for a 20A cell, (100w. Means you'd have 200w / hour unused, to cover losses. not entirely sure that is reasonable. The array provides charging voltage, so no losses from the array "to" the battery bank. But then there is the invertor, to go from the battery-bank, to the cell PSU, which in turn has it's own transformer, and a second set of losses. I wonder if there is a 12-14.4v buck convertor that will output "cell voltage", preferably slightly adjustable for fine tuning. Skipping the invertor would remove one set of losses.) and go grab a bunch of batteries from old trucks with sleeper cabs. Especially if these trucks have been used in cold weather, they swap the batteries "early", and there are lots of life left in them. The fact that they are 200-300A and 12v doesn't hurt either. 3 or 4 should be just enough to get through the night, so 5-6, would make sure you never have to deplete them entirely, and give you some small reserve for when the weather sucks some day. Every now and then you'd have to let the system "charge up" fully, if you have a lot of crappy weather, something like not using it at all the day you recover the product from the cell, or similar.

Makes a lot more sense to me, then hooking a solar system to the house, and try to offset costs on power bills that way. (Here in Sweden you are forced to use a metering-unit to keep track of how much electricity you produced, so that a energy company can "buy" it from you, and then sell it back to you, just so that the government gets their taxes... But if it's not "household power" you can skirt the rules.)

Hi MrB,

 

I like your line of thinking.

 

Inverters DO waste a lot of power, BUT if the energy source is free (solar), after the initial setup expenses catch up with the cost of paying a power company for electricity, the whole system costs less overall. The idea of using cheap or free batteries for the system backup makes it even more attractive.

 

A purchased or fabricated windmill could also supplement the solar component for power generation. I believe some controllers have the capacity to accommodate that option. I've wondered if an automotive alternator could be modified to use wind as the prime mover to produce 12 Vdc power for a battery bank (multiple 12 Vdc batteries connected in parallel)? I may try it as an experiment sometime in the future. It would be interesting to see if,

• it worked, and
• if it were practical.

As a supplement to a photovoltaic array, it could be very useful.

 

WSM

 

Edit: If you use an alternate system to avoid using an inverter, be sure to add in a filter to clean up the DC output. Batteries don't like ripple (AC components on the DC feed). A Pi filter usually helps.

Edited September 29, 2017 by WSM

[WSM]

The problem with solar power is that even in the sunnyest places there will be no more than 8 hours of power sunlight in a typical day, AND chlorate and perc electrodes don't stand leaving in the liquid when there is no power to them

The basic idea for solar power came from an old plant I once had to electrolyticaly recover silver from photo fixer.

The cell was above the reservoir tank and had three connections,

one the bottom drain simply let the liquid drain back into the reservoir tank to protect the electrodes when the power went off,

the second was a large overflow so that the cell couldn't possibly overflow

the third was the pumped feed from the reservoir to the cell using a magnetically coupled chemically resistant pump (Iwaki again off an old photo processor)

The big challenge for this process will be controlling the temperature of the cell -it must be warm to work while letting the solution off the electrodes when the solar is off.

Adding batteries and an inverter adds more cost and the limited life of cycled batteries (say 1000 cycles) adds more cost.

Heat is generated in the cell by current lost to electrolysis, in a simple cell the heat goes out the cell walls and top and equilibrium is achieved when heat generated equals heat loss at a certain temperature. When heat is lost by flow to the holding reservoir as well then there will be more variables to determine the current needed to maintain adequate cell temperature.

I can see that two cells in series (say 10v) run off a 500w solar array and manually connected every morning and disconnected every evening would be an off grid start up project, But it's manual. A small cell could be raised on jack screws by first solar of the day .......

 

A friend and fellow enthusiast described a similar system to me nearly a decade ago. He said he'd tried a multi-tank system with the reaction chamber (RC) higher than the reservoir, connected with a pump. The attractive part is, if the power fails, the electrolyte drains out of the RC back down to the reservoir tank, leaving the electrodes "high and dry". He abandoned that scheme and later created a continuous KClO₃ cell which he ran periodically for years, which worked very well until he retired it.

 

You're right about not leaving the electrodes in the mother liquor with the power off. The electrodes will be negatively affected.

 

I like the description you give of the RC with three ports (the inlet, outlet and overflow). I may incorporate that design into one of my experimental cells.

 

WSM

[WSM]

Perchlorate and chlorates are still available in the USA, however, they might eventually be banned (CPSC?). On that day, I might be utilizing the existing photovoltaic gear that is currently a power backup for the well pump. (Came in handy for Hurricane Irma last week, when there was no power for 6 days). Some lead dioxide and MMO/Ti electrodes may be in my future✴ The solar panels, batteries, charge controller, and inverter should be of sufficient capacity to run the chlorate cell's PSU, day and night, at a high enough current for proper efficiency and operating temperature and to prevent unwanted crystallization from night time cooling. (Dog not included)

 

Hey Petey, that's a nice setup. Thanks for sharing (how much extra for the dog? ).

 

I hope that your cleanup after the storm goes well.

 

If you need any tips with building a chlorate or perchlorate cell, ask us here. Most of us here are willing to share our (sometimes) hard won knowledge.

 

WSM

[PeteyPyro]

Thanks, WSM. Cleanup is ongoing. We've been using solar generated & battery stored electricity for off grid backup for the well pump (9kwh), shops (32 kwh), and house power (58kwh) for years, and have our infrastructure set for when the grid goes down. The investment really paid off during hurricane Irma and the weeks without grid power. I've been reading the long "making potassium (per) chlorate" thread (238 pages?) started a decade ago, and have gleened lots of great info from Swede, mumbles, as well as your very valuable input. When I eventually do start up an electrochemical cell, I'll definitely count upon your hard learned expertise. I don't want to reinvent the wheel, since so many have already blazed the trail here. I do LOVE the idea of "free" energy churning out POUNDS per month of potassium chlorate, from 50 cent a pound "water softener" salt. I'm eyeing plastic materials in the meanwhile, since they are replumbing the city, and discarding lots of nice HDPE pipe leftovers. It's amazing what the utility workers gave me for the price of a case of beer. 😎

BTW, WSM is also the abbreviation for Winchester Short Magnum. .300 WSM is my favorite "WSM". <grin>

Edited September 29, 2017 by PeteyPyro

[MrB]

I've wondered if an automotive alternator could be modified to use wind as the prime mover to produce 12 Vdc power for a battery bank

 

Could? Sure. Useful & effective? Not really. Reservation for some unobtanium style generator used in some vehicle i don't know about, automotive alternators have a set of very weak permanent magnets to get current flowing, and then feed the generated current back in to the electromagnets creating a stronger magnetic field, and with that, more current can be extracted. Very creative construction, and very smart. But not really that great for small windpower-setups. It means there is a lot of resistance as soon as it starts spinning, just to generate the current needed to get up and running. So to speak.

First when the alternator is properly energized will it start returning "charge", and i THINK it has to be turning at something like 1000-1500 rpm. Honestly, if wind is supposed to be used as a reserve power for the solarsystem, buy the wind-mill.

 

 

Edit: If you use a system to avoid using an inverter, be sure to add in a filter to clean up the DC output. Batteries don't like ripple (AC components on the DC feed). A Pi filter usually helps.

 

IF i was to do anything like this (i doubt it) i would run a controller between the solar arrays, and the battery. If there is to be wind-power included, then the controller would have to be one that can handle both. Personally, i don't care much for wind-power. Water, sure, wind, not so much. Anyway, such a controller should have ripple suppression. The buck-convertor for DC-DC voltage regulation powering the cell would make sure nothing gets to go "upstream" and cause havoc as well.

[WSM]

Well, my workshop/man cave is coming together nicely. I've got a friend who's a contractor that offered to hook me up with solar panels and equipment at cost. I plan to use battery backup with a controller and inverter as well. I'm seriously considering it to use as supplemental power for my projects.

 

My current plans are to run a 240 Vac line from the house to a subpanel I mounted inside, which will feed 120 Vac power to the lights and power outlets plus a 240 V outlet for higher power equipment. If I do the solar option, it'll be a separate wiring setup, with an option to feed extension cords to the house for temporary emergency power for the refrigerator and some lights. We don't loose power often, but it's nice to be prepared if it does happen.

 

I'm also considering adding a heat pump to the workshop, for heating/cooling and year round comfort when I'm working out there. It's good to learn that there are affordable options in this venture. It's especially nice to have a separate structure to house my projects, and my Wife is happy to see the back yard get decluttered of all my experimental bits and pieces.

 

I'm planning to move my covered workbench to just outside the workshop and have a covered outlet already in place. I may build an enclosure for the electrochemical experiments as sort of a lean-to on the workshop, with proper venting, lights and accessories in place. We'll see how this develops...

 

WSM

[PeteyPyro]

Sounds like a great setup, WSM. One thing that I discovered the hard way, was just how corrosive even barely detectable traces of chlorine gas are. Only 6 months of barely detectable chlorine fumes have badly corroded steel and aluminum in a shed outdoors. The door's hinges had a fluffy iron chloride, hygroscopically turning into rust colored stains dripping down the painted door. And apparently iron chloride also melts at the 100°f plus temperatures sometimes encountered there. It's a mess. An aluminum ladder in there turned into a white fuzzy ladder, I'm guessing that chlorine fumes turns most metals into a mess. Lesson: now I make sure that positive ventilation removes ANY & ALL traces of electrochemical generated chlorine from a cell.

[pyrojig]

I like this contractor fellow ... Maybe I can set up a similar setup , and get my act together.( ).I might be due for a project .Been a long time since i had electrochemistry excitement to wake up to . Kinda addicting adventure .

[WSM]

Sounds like a great setup, WSM. One thing that I discovered the hard way, was just how corrosive even barely detectable traces of chlorine gas are. Only 6 months of barely detectable chlorine fumes have badly corroded steel and aluminum in a shed outdoors. The door's hinges had a fluffy iron chloride, hygroscopically turning into rust colored stains dripping down the painted door. And apparently iron chloride also melts at the 100°f plus temperatures sometimes encountered there. It's a mess. An aluminum ladder in there turned into a white fuzzy ladder, I'm guessing that chlorine fumes turns most metals into a mess. Lesson: now I make sure that positive ventilation removes ANY & ALL traces of electrochemical generated chlorine from a cell.

 

Yes.

 

A lean-to type structure, as I envision it, won't be sealed but will have ample (passive) ventilation to prevent corrosive build up inside. Active ventilation can be fabricated as well, using polymer components able to withstand corrosive fumes or gases.

 

Thanks for sharing the unfortunate experiences with metal tools and structures exposed to chlorine/chlorine products. All of us should keep these details in mind when designing chemical handling facilities (even on a hobbiest scale).

 

WSM

[WSM]

I like this contractor fellow ... Maybe I can set up a similar setup , and get my act together.( ).I might be due for a project .Been a long time since i had electrochemistry excitement to wake up to . Kinda addicting adventure .

 

Yeah, he's a nice guy (and a fellow pyrotechnist).

 

Once I get the outside perimeter of my workshop more completed* I want to resume my chemical purification and electrochemical experiments. Among them are one or more bucket cells (there; I knew I could get back on topic !).

 

WSM

 

Edit: *I'm looking for affordable paver stones to lay around the workshop for ground surface stabilization of the soil and a skirt on the bottom of the shed to prevent the incursion of furry little vermin under it (even though I live in a suburban setting, we have skunks, possums, raccoons and squirrels running around, getting into things and creating a mess wherever they go).

Edited January 20, 2018 by WSM

[WSM]

I like this contractor fellow ... Maybe I can set up a similar setup , and get my act together.( ).I might be due for a project .Been a long time since i had electrochemistry excitement to wake up to . Kinda addicting adventure .

 

Yeah, me too.

 

Weather and time permitting, I need to get my stuff set up and running (maybe by Summer? We'll see...).

 

WSM

[athlon]

Hi ,guys! I need some MMO anodes and platinum cathodes. Please respond with PM...

[Scorpion812]

nonono,

you dont need PLATINUM cathodes, you use Ti for the cathode

[WSM]

That's true. I missed the statement about using platinum for the cathode.

 

If anything, platinum would be used for an anode, not the cathode. Platinum's expense has me reserving it for electrolysing sodium chlorate solution to form sodium perchlorate, which is used in making other perchlorates.

 

When searching for titanium to use for a cathode, be sure to get CP (commercially pure) grades.

 

Good luck.

 

WSM

Edited June 14, 2018 by WSM

[memo]

I have my cell back up and running ay about 36 hours I switched from platinized ti to a mmo . my water turned black in about 5 minutes. any idea what is happening and why ?

memo

[memo]

update i shut the cell down pulled everything out of the solution and let it sit about 30 minutes and all the black settled to the bottom. what do you think ?

[Baldor]

MMO falling from the electrode?