Mark III Advanced Pressure Control / Deuterium Generation from D2O / Metal Hydride Storage

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Andrew Seltzman
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Re: Mark III Advanced Pressure Control / Deuterium Generation from D2O / Metal Hydride Storage

Post by Andrew Seltzman »

Latest tests:

Charging pressure from hydrofill pro is about 270psi for steady state operation, this is just the output pressure from the fuel cell, no compressor is used.
Over a 1h run blanked off against a pressure gauge: for the first ~10min no D2 is produced, then pressure climbed rapidly to 300psi over 2min, then slowly to 335psi over the next two min, then slowly dropped to 270psi over the next 10min and held that pressure until it was turned off. I know it has a pressure sensor inside, possibly a digital pressure gauge though it may also be a pressure switch. It says the rated output pressure is 435psi and it never reached this level, it's possibly the microcontroller has some intelligent gas pressure regulator to determine the best output though.
chraging presure.png
Metal hydride cartridges have an outlet pressure of ~250psi
metal hydride pressure.png
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Richard Hull
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Re: Mark III Advanced Pressure Control / Deuterium Generation from D2O / Metal Hydride Storage

Post by Richard Hull »

Amazing! Your own little tank of D2 at a pressure that will allow for many runs of a stock fusor. A very nice and for sure a rather costly little system that you have reported on before. While I have a larger tanked system and two PEM cells, if needed in future, your system is sort of a middle ground that in many ways is ideal.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
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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Re: Mark III Advanced Pressure Control / Deuterium Generation from D2O / Metal Hydride Storage

Post by Andrew Seltzman »

More tests on the Hydrofill PRO.

The circuit boards have a KA7500 switchmode controller chip running a buck converter connected to the fuel cell. and an Holtek HTT46R066B microcontroller. The The pressure switch is digital and is connected to pin 16 of the microcontroller (a digital i/o line). The switch pulls the i/o pin high to 5v when closed. Measurements on the fuel cell indicate a voltage between 3.06V-3.2V and current between 7.9A-8.75A. Connecting the switch i/o pin to 5v through a 2k resistor turns off fuel cell current. Doing this a few times shuts down the fill cycle on the cartridge (turns the status light solid green, shuts down fuel cell current). I believe the purge cycle on the molecular sieve hydrogen purifying column is triggered through a timer and not a pressure sensor. The cartridge connector on the Hydrofill has a check valve on it so venting the water trap / molecular sieve column does not empty any deuterium from the cartridge. There is no pin on the fitting to open the cartridge valve so it is opened by pressure alone.

Circuit Board front/back
circuit front.png
curcuit rear.png
Current measurement on cell
current cell.png
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Matt_Gibson
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Re: Mark III Advanced Pressure Control / Deuterium Generation from D2O / Metal Hydride Storage

Post by Matt_Gibson »

Thought I would revive this thread now that I see deuterium lecture bottles have doubled in price ($800 plus shipping hazmat).

Has anymore work been done with these? Any chance someone with one of these might be willing to fill a hydrostik if we supply the hydrostik and the heavy water?

I can’t see myself paying $1k for a lecture bottle once mine runs out…

-Matt
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Emma Black
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Re: Mark III Advanced Pressure Control / Deuterium Generation from D2O / Metal Hydride Storage

Post by Emma Black »

I've been using these for a while now and so far have been working great, much easier than messing around with the syringe and pem arrangement. Each one lasted many months and the refill station has worked well. I got a ridiculous quote of £1300 + shipping for a normal gas bottle here.

Pretty sure Andrew is still able to supply filled cartridges - although the powers that be didn't seem to like these being shipped internationally. I'm also happy to supply these at cost for any UK folks, they work out about £100 each.
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Re: Mark III Advanced Pressure Control / Deuterium Generation from D2O / Metal Hydride Storage

Post by Matt_Gibson »

Hi Emma,

What are you using for a regulator on the hydrostik?

-Matt
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Emma Black
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Re: Mark III Advanced Pressure Control / Deuterium Generation from D2O / Metal Hydride Storage

Post by Emma Black »

I'm using the Horizon one, it screws onto the cartridge and it drops the pressure right down:
https://www.h2planet.eu/en/detail/one_s ... egulator_1

Same one as in the photo at the top of the thread.

Each recharge using the refill station about 30g of D2O.
IMG_4451.jpg
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Re: Mark III Advanced Pressure Control / Deuterium Generation from D2O / Metal Hydride Storage

Post by Andrew Seltzman »

The purge solenoid on my Hydrofill unit failed, fortunately it's pretty easy to find on ebay. I have 2 backup electrolyzers so not an issue for deuterium generation, but hopefully I'll have this one fixed
It's a 3v, 10ohm coil, with a normaly closed config
https://www.ebay.com/itm/262673367726
$_57.JPG
s-l1600.jpg
While I had the unit apart I decided to replace the silicone hoses which were degrading and examine the other components inside. All the hose connections are o-ring sealed with a washers compressing a rectangular o-ring against the stainless tube and the seat of a threaded fitting. They are pretty east to remove.
PXL_20231209_015012324.jpg
PXL_20231209_015016560.jpg
PXL_20231209_015026283.jpg
PXL_20231209_015158882.jpg
This unit turned out to be a combination of a reservoir to collect water that made it through the electrolysis, and a pressure regulator to limit the pressure the purge solenoid must handle. The output is over 300psi, but the solenoid is probably limited to about 10-20psi. When the solenoid opens any water in the reservoir is forced out.
PXL_20231209_014837528.jpg
PXL_20231209_014829545.jpg
PXL_20231209_014623774.jpg
PXL_20231209_014611795.jpg
PXL_20231209_014607816.jpg
PXL_20231209_014558854.jpg
PXL_20231209_014537952.MP.jpg
PXL_20231209_014529587.jpg
PXL_20231209_014515784.jpg
The other cylinder as expected appears to be some manner of molecular sieve for purifying the hydrogen/deuterium.
PXL_20231209_015206836.jpg
Appears to have some sort of relief valve on the bottom
PXL_20231209_015219690.jpg
x-rays show some powder inside and you can hear something granular when you shake it
Image__2023-12-08__21-20-17.png
Last edited by Andrew Seltzman on Sat Dec 09, 2023 8:12 pm, edited 1 time in total.
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Richard Hull
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Re: Mark III Advanced Pressure Control / Deuterium Generation from D2O / Metal Hydride Storage

Post by Richard Hull »

I noted earlier last year, I think, that the price of heavy water has definitely more than doubled in the last decade. Are production costs increased? There is a limitless supply on earth of raw material (water). I might imagine labor costs, regulations and the electricity demanded in production have increased. I would hate to think someone, entity, nation state, etc. is building up a stockpile of D2 gas or heavy water and bidding the price upwards as it comes on the market. Supply and demand. Same goes for tanked gas as D2 gas isn't found in nature and must come from electrolysis in the end.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
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
Andrew Seltzman
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Re: Mark III Advanced Pressure Control / Deuterium Generation from D2O / Metal Hydride Storage

Post by Andrew Seltzman »

Unfortunately it seems this electrolyzer has died (fortunately I have 2 more). The replacement solenoid valve did fix the problem, but it stall wasn't producing deuterium at anywhere near the rate it should. It was producing 0.3l/h and should be producing 3l/h. Blanked off against a pressure gauge, the cell would still produce about 400psi output but at very low supply rate. Cell voltage was at the maximum 5v the board could supply and it was only drawing a few hundred mA. Connecting the cell directly to a power supply required 12-13V across the cell (normal voltage should be 2-3v) to drive the required ~8A. At this current the cell would produce the required 3l/h but would rapidly overheat due to the increased power dissipation. This effect points to PEM membrane degradation (see fig 2) in following paper.
https://h2tools.org/sites/default/files ... er_194.pdf
I decided to dismantle this unit for exploration an possibly future repair.
PXL_20240211_023915089.jpg
The fitting the hydride cartridge screws into also has a pressure relief valve on the back that was not previously visible.
The PEM cell has an M5 output thread, which will also fit a 10-32 face seal pneumatic fitting rather than the internal o-ring they designed. The bolts holding the steel plates (1/4" thick on the water side, 1/2" thick on the deuterium side) were torqued to about 16 in-Lbs as assembled.
PXL_20240211_031528643.jpg
Halves are sealed with a silicone o-ring
PXL_20240211_031922798.jpg
There is an array of channels to allow water access to the cell electrodes and membrane.
PXL_20240211_031927850.jpg
The electrode feed throughs are sealed with RTV
PXL_20240211_031932720.jpg
PXL_20240211_032007009.jpg
The output fitting is stainless and has a fiberglass backup washer
PXL_20240211_032144944.jpg
The metal mesh electrode is spot welded to another finer metal mesh and lays on top on another fine metal mesh. These electrodes have some oxidation (rust?) on them and the water in the electrolyser was starting to get a very fine rust particulate material in it when the electrolyser was run. The good ones don't have this issue.
PXL_20240211_032647374.jpg
Under this electrode is the polymer PEM membrane
PXL_20240211_033212572.jpg
The OEM membrane is bonded to a graphite cloth presumably impregnated with a catalyst. The membrane surface abuts an o-ring that steels it against the opposing electrode to trap the deuterium, a hole drilled through the stack to the other end allows deuterium to diffuse to the center and exit the electrolyzer
PXL_20240211_033320659.jpg
A rigid graphite plate contacts the graphite cloth on the membrane
PXL_20240211_033547315.jpg
The sealing o-ring is removed
PXL_20240211_033711022.jpg
The negative electrode is bonded to a graphite cloth that contacts the graphite plate
PXL_20240211_033916680.jpg
The hole through the electrode allows the deuterium to exit
PXL_20240211_033957863.jpg
and is sealed to the output fitting with an o-ring
PXL_20240211_034016776.jpg
Resistance measurements are as follows
PXL_20240211_033439662.jpg
PXL_20240211_033451638.jpg
PXL_20240211_033519657.jpg
PXL_20240211_033933633.jpg
Does anyone have a guess on the exact type of membrane?
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Dennis P Brown
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Re: Mark III Advanced Pressure Control / Deuterium Generation from D2O / Metal Hydride Storage

Post by Dennis P Brown »

Outstanding disassembly sequence/photo's and diagnostics.
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