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

For posts specifically relating to fusor design, construction, and operation.
Andrew Seltzman
Posts: 755
Joined: Mon Feb 02, 2004 1:02 am
Real name: Andrew Seltzman
Contact:

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

Post by Andrew Seltzman » Thu Mar 12, 2020 3:02 am

I tested the fusor with the deuterium from the metal hydride cartridge and found equivalent performance to the deuterium from the lecture bottle. Due to some arcing from a damaged grid insulator, voltage was limited to 30kV. A run with a deuterium lecture bottle was followed by a run with the metal hydride cartridge, which was followed by another run with the lecture bottle. Purging of the fuel lines brought the core up to a few torr of air, followed by a few torr of D2 between each run.

Run parameters for both runs were:
30kV, 17.4mA, 10mTorr, ~200k n/s

So that's a confirmation that it will work.

Lecture bottle and metal hydride cartridge
IMG_20200311_223453589.jpg
lose up of metal hydride cartridge, regulator, and connection to piezo valve
IMG_20200311_223505220.jpg
Star mode with metal hydride cartridge
IMG_20200311_223733286.jpg
Andrew Seltzman
www.rtftechnologies.org

User avatar
Rich Feldman
Posts: 1296
Joined: Mon Dec 21, 2009 11:59 pm
Real name: Rich Feldman
Location: Santa Clara County, CA, USA

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

Post by Rich Feldman » Thu Mar 12, 2020 3:14 am

That is really cool, Andrew. Hip, hip, hooray!

Might well be a "first time in the world" demonstration, without needing many words of qualification.

Confirms that gas dry enough to put into hydride cartridges is dry enough for fusing.
All models are wrong; some models are useful. -- George Box

Andrew Seltzman
Posts: 755
Joined: Mon Feb 02, 2004 1:02 am
Real name: Andrew Seltzman
Contact:

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

Post by Andrew Seltzman » Sat Mar 14, 2020 1:31 am

I recently dismantled one of the used metal hydride cartidges that would no longer take a charge.

The top screws on, though I was unable to find a way to unscrew it, it may be epoxied in place
IMG_20200312_223728291.jpg
There are threads on the ID of the cylinder
hydrostick1.jpg
hydrostick1.jpg (25.15 KiB) Viewed 591 times
Cutting the cylinder with a tube cutter removed the top. It is filled with loose powder
IMG_20200313_114639214.jpg
The casing is pretty thick, about 1/8"
IMG_20200313_114724975.jpg
The cap contains a filter assembly to prevent powder from getting out, and a valve that is opened by depressing the pin
IMG_20200313_114643311.jpg
XRF analysis on the powder indicated it's composition by mass is
70.9% Ni
21.1% La
6.92% Ce
0.42% Cr
0.68% Mn

The powder is almost certainly Lanthanum pentanickel (LaNi5), a common AB5 metal hydride for hydrogen storage. The other elements are likely impurities, probably reflecting the low cost compared to commercial reagent grade LaNi5, though it obviously doesn't seem to affect storage.
https://www.sigmaaldrich.com/catalog/pr ... &region=US
Andrew Seltzman
www.rtftechnologies.org

Rex Allers
Posts: 435
Joined: Sun Dec 30, 2012 8:39 am
Real name:
Location: San Jose CA

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

Post by Rex Allers » Sat Mar 14, 2020 10:50 am

Great stuff Andrew. Thanks for taking it all the way to fusion and sharing the results.

Good info (with resources not available to many) on what is inside too.
You said, "one of the used metal hydride cartidges that would no longer take a charge."

Any idea why it wouldn't take a charge?
Rex Allers

Andrew Seltzman
Posts: 755
Joined: Mon Feb 02, 2004 1:02 am
Real name: Andrew Seltzman
Contact:

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

Post by Andrew Seltzman » Sat Mar 14, 2020 2:57 pm

It was a used one that I got on ebay with a Brunton Reactor fuel cell. It was left screwed into the fuel cell for probably long after it was empty and air with moisture likely got in (by permeating through the fuel cell membrane after there was no flow of hydrogen out of the cartridge) and destroyed the metal hydride.
Andrew Seltzman
www.rtftechnologies.org

User avatar
Rich Feldman
Posts: 1296
Joined: Mon Dec 21, 2009 11:59 pm
Real name: Rich Feldman
Location: Santa Clara County, CA, USA

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

Post by Rich Feldman » Sun Mar 15, 2020 12:57 am

Fascinating. Probably not good stuff to eat or get in your eye! Nice that you identified it as a standard formulation. Online searches for charge/discharge pressure curves etc. need not be limited to Hydrostik brand.

Andrew, would you be interested in helping to answer an old question, by doing one more "assay by fusor"?

Right here is one Brunton core that was bought new, a few years ago, and run to shut-down in a fuel cell while ampere hours were logged. Then immediately disconnected, and stored clean and dry with whatever residual hydrogen is left in it.
If you have no such thing on hand, you can have mine as a gift. Hope you can then repeat your fill-and-fuse exercise, with no special effort to purge the regular H2.
Neutron yields in a stable system are easier to measure than H2/D2 ratios (and more relevant), for those of us without mass spectrometers.

p.s. Harold Urey's discovery of deuterium used a high-resolution optical spectrometer. But he had to do a lot of enriching, by letting LH2 boil down, before there was enough D to detect that way. First trial failed because the H2 was prepared by electrolysis, and was deuterium-depleted to begin with!
Mass spectrometry had been developed, and had already measured the stable isotopes of all other light elements. But deuterium was hiding behind molecular ion H2+ in the mass 2 channel. Soon after Urey's report, deuterium in enriched samples was confirmed in the mass 3 channel, as HD+. There ought to be no such problem using a mass spec. to measure H contamination in D.
All models are wrong; some models are useful. -- George Box

Andrew Seltzman
Posts: 755
Joined: Mon Feb 02, 2004 1:02 am
Real name: Andrew Seltzman
Contact:

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

Post by Andrew Seltzman » Sun Mar 15, 2020 4:44 am

No special method to purge the residual hydrogen was used on my metal hydride cartridges. They were emptied of H2 down to atmospheric pressure then filled with D2. The H2 to D2 ratio would probably be a few ml H2 per 11L D2.
Andrew Seltzman
www.rtftechnologies.org

ian_krase
Posts: 629
Joined: Mon Nov 28, 2016 7:48 am
Real name: Ian Krase

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

Post by ian_krase » Sun Mar 15, 2020 8:02 am

Beware -- hydrogen storage material is sometimes pyrophoric!

User avatar
Rich Feldman
Posts: 1296
Joined: Mon Dec 21, 2009 11:59 pm
Real name: Rich Feldman
Location: Santa Clara County, CA, USA

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

Post by Rich Feldman » Sun Mar 15, 2020 7:06 pm

Andrew, thanks for response about the residual hydrogen question. Back in 2016, technical sales told us that unlike the Brunton cores, new Hydrostiks came evacuated. That suggested no extractable hydrogen, or even argon/nitrogen from the factory atmosphere, and that a new cartridge would weigh more after filling and then emptying to 0 psig. Have you heard or found otherwise?

Am still having trouble making sense of this chart, from a European maker (or seller) of hydrogen storage cartridges:
https://www.pragma-industries.com/broch ... -V2019.pdf
hydrides2.png
hydrides2.png (138.88 KiB) Viewed 473 times
Perhaps very generic, and old, but it seems to show most of the hydrogen locked up at 1 bar! Maybe something was lost in translation.
For material comparisons, one would think the capacity at some stated (or conventional) absolute P_min is just as important as the capacity at P_max.

Andrew, it was insightful to show us the Sigma Aldrich unit prices for hydrogen storage media,
which (in 10g quantities) are many times the retail price of whole Hydrostiks or Hydrocores.

Online documentation taught me some things about Hydrostik and Hydrostik Pro.
The latter supports faster charging and discharging, "for educational applications", using a different storage medium.
The former uses a TiMn2 formula according to one document, and an "AB5" according to another. https://www.horizonfuelcell.com/minipak

Did the non-Pro Hydrostik and Hydrofill get discontinued, or just re-named and labeled?
Hard to find non-Pro stuff online today, except that minipak brochure and this old Hydrofill manual (version 13 :
resources.arcolaenergy.com/docs/Manuals/HYDROFILL_Manual_V13.pdf

One paper lists a bunch of LaNi5 variants, with other elements replacing some of the nickel. They don't show the ceriated flavor that you found.
hydrides.png
hydrides.png (98.29 KiB) Viewed 473 times
from fcto_h2_storage_summit_motyka.pdf

Can't find the documentation from an instrument maker whose hydrogen storage medium is/was depleted uranium powder.
All models are wrong; some models are useful. -- George Box

Andrew Seltzman
Posts: 755
Joined: Mon Feb 02, 2004 1:02 am
Real name: Andrew Seltzman
Contact:

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

Post by Andrew Seltzman » Sun Mar 15, 2020 8:10 pm

I think the non pro versions were discontinued.
The one I took apart was the brunton hydrocore (a rebranded hydrostick pro).
Both the Brunton hydrocore, and the hydrostik pro version come full with hydrogen.

Depleated uranium is usually only used for storing tritium. It has to be heated to several hundred C to release the tritium which gives a level of protection against accidental release if the canister is damaged since it will not desorb unless heated.
Andrew Seltzman
www.rtftechnologies.org

Post Reply