PEM fuel cell deuterium generator

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Bob Reite
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Re: PEM fuel cell deuterium generator

Post by Bob Reite »

I took a two hole stopper and used a drill press to drill the third hole for my system.
The more reactive the materials, the more spectacular the failures.
The testing isn't over until the prototype is destroyed.
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Dennis P Brown
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Re: PEM fuel cell deuterium generator

Post by Dennis P Brown »

Really an informative post since it is so difficult to get compressed deuterium gas! Good details, too.

The fuel cell is the exact one my daughter used for her "hydrogen" powered mini-model car (worked very well.) She had/used a solar cell to create the hydrogen (& oxygen) gas.
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Rich Feldman
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Re: PEM fuel cell deuterium generator

Post by Rich Feldman »

What could be greener than H2 fuel made by electrolysis, using electricity from PV cells?
But people using lots of H2, such as for oil refining or ammonia-making (space shuttle fuel tanks were a drop in the bucket) know that
"Today, 95% of the hydrogen produced in the United States is made by natural gas reforming in large central plants."
Ref: http://energy.gov/eere/fuelcells/hydrogen-production

So electric cars powered by hydrogen fuel cells are just a more efficient fossil-fuel-driven technology.
But way cool, and hobby-scale PEM cells are a fringe benefit.
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Adam Szendrey
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Re: PEM fuel cell deuterium generator

Post by Adam Szendrey »

I'd say this is realted:
http://fuelcellstore.com/fuel-cell-stac ... -fuel-cell

Cheap, "reversible" (well all of them are really...maybe it's made to be more compatible (separate water fill inlet or something) with reverse operation? Not sure) PEM cell. 7 ml/min (claimed), not the fastest thing out there, but if you use a reservoir as suggested here, it can produce all the deuterium you need, on the cheap.

https://www.youtube.com/watch?v=oRpSfsE1zUg

Indeed seems to have a separate (third) port for filling...?

Glad to have found this thread, as I'm planning on using heavy water as well. 10 liters of D2 would cost me a whopping 280 USD...No thanks. I can get that from about a gram of D2O.
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Dave Xanatos
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Re: PEM fuel cell deuterium generator

Post by Dave Xanatos »

See what you all made me do???

:)
Parts6.jpg
Parts7.jpg
Parts8.jpg
My machinist is awesome.
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Richard Hull
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Re: PEM fuel cell deuterium generator

Post by Richard Hull »

Nice finish on the item.

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Fusion is the energy of the future....and it always will be
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Re: PEM fuel cell deuterium generator

Post by AllenWallace »

Really nice! Are you going to put in a float switch or equivalent which will allow auto-demand?
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Dave Xanatos
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Re: PEM fuel cell deuterium generator

Post by Dave Xanatos »

AllenWallace wrote:Really nice! Are you going to put in a float switch or equivalent which will allow auto-demand?
Hadn't thought of that, but I like the idea! Thanks!
It would take decades of work, by thousands of scientists, in a particle accelerator powered by dump trucks of flaming grant money! - Professor Farnsworth/FUTURAMA
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Re: PEM fuel cell deuterium generator

Post by Dave Xanatos »

Deuterium Generator installed on the portable demo fusor...
Generator1.jpg
Generator2.jpg
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Rich Feldman
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Re: PEM fuel cell deuterium generator

Post by Rich Feldman »

Ooh! Aah!
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Charles Vorbach
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Re: PEM fuel cell deuterium generator

Post by Charles Vorbach »

Beautiful. Much less hacked together than my supply.

I am curious though, is the D2 really wet when produced from a PEM cell? Most of the diagrams I have seen seem to show the PEM membrane as impermeable to water.

Image
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Rich Feldman
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Re: PEM fuel cell deuterium generator

Post by Rich Feldman »

Same question was addressed a couple months ago in Erik Burrows's thread.
viewtopic.php?f=45&t=10592&p=70213#p70213

It would be nice if someone found or measured how much water comes through their Hydrocar cell,
or how much water it takes to interfere with or contaminate a fusor.

With a glass cold finger or u-tube condenser and various freezing baths,
or a Peltier-cooled shiny surface exposed to the gas,
it would easy to set bounds on the dew point temperature, hence the relative humidity. In D2.

Some day when I have a working fusor with fuel cell deuterium,
one of the first experimental variations will be to skip the drier and see what happens.
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Bob Reite
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Re: PEM fuel cell deuterium generator

Post by Bob Reite »

I also thought that the PEM cells were supposed to produce dry hydrogen, but after running mine for awhile, I do notice some condensation in the hydrogen output tubing, so I do have a drier between the over pressure protection system and the mass flow controller. A picture of my gas system is at download/file.php?id=8528&mode=view
The more reactive the materials, the more spectacular the failures.
The testing isn't over until the prototype is destroyed.
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Re: PEM fuel cell deuterium generator

Post by Dave Xanatos »

Just a quick design revision: note the increased diameter of the two crossover droptubes. This is to prevent too high of a pressure developing within the PEM Cell trying to push the vacuum oil through the small diameter tubing. The gas flow diameters are fine as they should never conduct oil. Also note the addition of the terminal block for easy hookup without having to mess with the PEM Cell.

0620162105b_resized.jpg
0620162105a_resized.jpg
0620162104_resized.jpg
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Brodie Reid
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Re: PEM fuel cell deuterium generator

Post by Brodie Reid »

I plan on using this method for my Deuterium source, however I do have one question. What exactly are the oil resevoirs and if anyone could post a link to where to get them (or how to make them), I would really appreciate it!

Thanks,
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Bob Reite
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Re: PEM fuel cell deuterium generator

Post by Bob Reite »

I used some old medicine bottles and rubber stoppers for my system. The photos above show a fancy custom built system. There is more than one way to do it.
The more reactive the materials, the more spectacular the failures.
The testing isn't over until the prototype is destroyed.
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Re: PEM fuel cell deuterium generator

Post by Rex Allers »

I haven't built a generator like this yet, but I have accumulated parts (PEM cell, plumbing, valves, etc.).

My thought for a buffer holding chamber for the gas was to use a small mylar balloon rather than these oil displacing chambers. My thought was that it would be easy to suck oil if you want to evacuate to keep the D2 as pure as possible, or even from the chamber vacuum if you aren't watching enough. Seemed to me the balloon could be evacuated without a problem.
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Re: PEM fuel cell deuterium generator

Post by Rich Feldman »

My story is like Rex's. Got hydrocar kits from craigslist & ebay, etc. Have a couple of Mylar balloons, but have not yet experimented with how to seal them to tubing. Found an ebay vendor who regularly sells D2O packaged in 50 gram lots for $75. You get only 45 ml because the water is, uh, heavy.

Storage in balloons misses one benefit easily achieved with gas-over-liquid reservoirs. That's "overpressure" relief in the vacuum plumbing. In case electrolytic gas production stops, we don't want a strong vacuum to develop on the PEM cell. If a PEM were supported to withstand vacuum, then we could skip the reservoirs and very-low-flow restrictor. Simply adjust electric current to set the D2 flow. No great technical problem there. Electrolytic "hydrostik" refillers run PEMs with hundreds of psi on the hydrogen side., as discussed in another thread.

[edit] Can also avoid risk of vacuum on PEM cell, by having no plumbing that connects reservoir to fusor flow control and PEM cell at the same time.

I learned that there's a well analyzed geometric shape called "Mylar balloon". From the nominal balloon size (diameter of flat circles sealed around the edge) we could figure the maximum inflated volume. I have not yet done that exercise, nor measured the volume using real fluid. I think that tables for party helium show 18" balloons needing about 1/2 cubic foot.
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Richard Hull
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Re: PEM fuel cell deuterium generator

Post by Richard Hull »

A rather inexpensive device with hydrogen and oxygen tanks (reversable PEM) for those experimenters. Might be adapatable....modifiable?

https://fuelcellstore.com/downloads/drf ... torage.pdf

Want just the reversable cell?.....

https://www.fuelcellstore.com/horizon-m ... -fuel-cell

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Re: PEM fuel cell deuterium generator

Post by Rex Allers »

On Richards two fuelcellstore links.

I've never seen the first one but it seems to have a lot of implementation that might be better done in ways that are more specific to meet our needs.

Second link is for a reversible device (can be a fuel cell or an electrolyser). I think we only really want to go in the electrolyser direction and the following link is slightly cheaper.
Horizon Mini PEM Electrolyzer
https://www.fuelcellstore.com/horizon-m ... ectrolyser

It's been several years since I looked into these things but I thought there might have been some advantage to the electrolyser for our intended use. Well there is a $6.50 advantage from prices listed today. Thought there was something I read once about differences that might matter, but couldn't swear to it and can't find it now.
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Mark Rowley
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Re: PEM fuel cell deuterium generator

Post by Mark Rowley »

Several of the Horizon PEM cell videos demonstrate gas collection in a syringe. If deuterium was collected in a large 100cc syringe, would the vacuum in a typical Fusor be sufficient to draw from it via a needle valve (resulting in the slow retraction of the plunger)? Or is it necessary that I have positive deuterium pressure?

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Bob Reite
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Re: PEM fuel cell deuterium generator

Post by Bob Reite »

The vacuum would be more than enough, you don't need pressure. In fact the PEM cell has to be protected from excessive positive or negative pressures.
The more reactive the materials, the more spectacular the failures.
The testing isn't over until the prototype is destroyed.
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Re: PEM fuel cell deuterium generator

Post by Rich Feldman »

Rex Allers has one of the PEM cell electrolyzers for refilling storage cartridges.
Puts out H2 even against back pressures of more than 400 psi.

As I've said before, maybe even in this very thread, there's no technical reason a membrane couldn't be supported on the hydrogen side, to withstand full vacuum. Then fusor gas flow would be controlled directly and immediately by the electrolyzer current setting.
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Re: PEM fuel cell deuterium generator

Post by Martiname »

Hi All,

I would like to build fully automatic Deuterium generator with PEM Cell. To avoid any unnecessary liquid parts (vacuum oil) I going to use only pressure switch with Over/Underpressure trip points.
Function will be very simple, D2 Gas will be generated by PEM Cell and keep in small vessell under overpressure max. 1100 mBar a, above this pressure D2 will be gently vented by solenoid valve with flow reducer and sintered filter. In normal function, Gas flow will be reduced by precise neeedle valve to Fusor chamber, there is possibilty to reduce generation of D2 by PWM PEM Cell control to avoid overpressure. And if acidentally decrease the pressure below 900 mBar a vent valve will be opened to avoid destroy PEM cell by this low pressure. I get a professional Peltier cooled cold trap (3.stage/-45°C), so this is reason why is used there.

Further description and block schematic is attached.

I would like to welcome any comments, mainly Iam not sure about min./max. pressure and overall function.

Many Thanks
Best Regards
Martin
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Richard Hull
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Re: PEM fuel cell deuterium generator

Post by Richard Hull »

The rebirth and commentary on this old 2014 posting is often seen in other posts. The rather complex system posted just above in 2021 is a nice exposition on what might be a superior system using a PEM cell.

However, for those not so well disposed to a complex system, a most miraculous system of rather great simplicity and used to create fusion far beyond the norm is presented in a FAQ in this forum!! This is the work of the dedicated Mark Rowley here at fusor.net, and In my estimation is one of the finest FAQs ever created due to its simplicity and its attention to detail coupled with solving in a simple and easy manner the often difficult issue for the amateur in obtaining deuterium gas for use in a fusor.

The amazing thing is that a full video exposition consisting of 3 videos will explain it all! This reduces the effort of PEM cell production of Deuterium gas in a highly successful fusion system to a "monkey-see-monkey-do" experience. Mark tells of how the produced gas is "not wet" and drying not absolutely needed! If drying was needed, Mark's large fusion numbers using his undried gas would not be possible.

This amazing FAQ can be seen and explored at.......

viewtopic.php?f=24&t=13995

Sit down and watch the videos in order. Take notes. Again, the beauty of Mark's system is its simplicity, low cost and proven workability to solve what is often a stumbling block on the road to amateur fusion.

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Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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