SupaVillain
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Separate Argon and Nitrogen from Cylinder?
So i have access to a 25%argon 75%nitrogen cylinder, anybody know how to separate them?
After looking at cms (carbon molecular sieves) they seem to hold oxygen while nitrogen passes through. If the nitrogen were the gas to be held back i
believe the argon would flow through but unfortunately it doesnt seem to be that way. I wonder if the argon would be absorbed into the carbon just
like oxygen?
Would love to use the argon for a 488nm laser for a fully automated cell sorter and for magnetron sputtering
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battoussai114
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I'll throw some ideas on the wind here:
Liquefy the N2: Not particularly easy but if you get yourself a refrigerator pump or something along this lines you could build a cryo-refrigerator
based on the joule-thompson effect. N2 should be easier to liquefy, and as such, separate.
Cryogenic absorption: As I posted somewhere in the forum (technochemistry or beginings I guess) I've been workin on a Cryogenic sorption vacuum pump
and based on what I read it seems noble gasses are particularly hard to get in the sieves. So you could work along these lines and build a system to,
at least, concentrate the argon.
Some reaction based separation: Not sure if it'd work but you could put this mixture in a previously evacuated chamber and get something to react with
the nitrogen... Maybe some really hot metal, similar to titanium sublimation devices used in high vacuum, would make some nitride and leave pure
argon.
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SupaVillain
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http://chem-brains.blogspot.com/2012/04/p-block-elements-ii-...
it seems as though cryogenic things are much better at producing all the different types of gases, i dont have any pumps like that but i do have
vacuum pumps. One that goes to 1x10-2 torr and a diffusion pump prolly reaching 1x10-4torr
i would think that unfortunately for retrieving rare gases like xenon and argon, it's going to take a lot of pumping time to get them in comparison to
oxygen and nitrogen....but then again it is the first process in the link above that pulls argon xenon and krypton into charcoal....
the real thing to ask though is.... will it be cheaper to make a system like this and have the gases i want (Ar and Xe) or will it be cheaper to buy
an argon cylinder and still never have xenon?
[Edited on 22-7-2015 by SupaVillain]
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battoussai114
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Depends on how much LN2 costs where you live. Coconut charcoal or 10X Molecular sieves aren't particularly expensive and since they can be regenerated
by heat treatment they'll remain useful for some long time. So Cryogenic Sorption seems cheap enough.
The idea of liquefying the mixture would be more expensive since you'd need machining and pumps, but then once the system is build you'd have your own
LN2 producing system at hand, and depending on where you live it's probably less expensive than buying LN2.
Reactive separation would mean loosing a piece of whatever metal you choose, but some metals are pretty inexpensive too. I paid like 3 bucks or less
for a high purity Tungsten electrode and I'm pretty sure if you pass a high enough current through it you'd get the nitride forming on it's surface.
If you already have vacuum pumps its not much money wasted on materials.
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annaandherdad
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Burn magnesium in it, it will get rid of most of the nitrogen.
Any other SF Bay chemists?
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j_sum1
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How easy would that be to do? Are you
going to get a self-sustaining flame? I doubt it since it is hard enough to light a piece of Mg ribbon in air sometimes. What kind of set up would
be needed to get this to work?
If you are after argon, there are other ways to get it and it need not be too expensive. Wine sellers often sell cans of argon for re-sealing bottles
of expensive wine. Welders' supplies are another. You might simply want to buy some argon and keep your 25-75 mix for when you want a non-specific
inert gas.
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m1tanker78
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Invest in an argon cylinder from a welding gas outlet. If you can't afford that, you probably can't afford a dodgy scheme to separate, refrigerate,
store compressed gas. It's kind of a hefty up front cost but you get relatively pure argon on demand and exchanges aren't expensive.
Chemical CURIOSITY KILLED THE CATalyst.
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SupaVillain
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You could have electrical feedthroughs in a closed container and burn the magnesium i believe, just like a normal PVD thin film setup
In reply to other posts....
I would honestly really like to make xenon gas and have all the other gases available for whatever i want to do with them. Youd be surprised how much
one can minimize costs when approaching things DIY if you really have faith in your ability to construct things
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BromicAcid
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Quote: Originally posted by battoussai114  | | Liquefy the N2: Not particularly easy but if you get yourself a refrigerator pump or something along this lines you could build a cryo-refrigerator
based on the joule-thompson effect. N2 should be easier to liquefy, and as such, separate. |
Certainly an understatement, I mean, how often have you seen a refrigerator get down to -196C? There are threads on this on the forum but cascade
cooling would be the way to go, i.e., one compressor cools the next in line cools the next in-line etc. Unfortunately this also requires changing the
refrigerant in the compressors to things like ethane which is also no trivial matter. Even with your disclaimer, it is much easier said than done.
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SupaVillain
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Looking at the joule thomson effect/joule expansion for cryogenic temperatures i could easily vacuum my chamber out and open it up to another chamber
to cause it but.... i dont know at which rate i would do this, and too fast would cause considerable implosion danger to me and my pretties. My dearly
beloved valves and feedthroughs
[Edited on 23-7-2015 by SupaVillain]
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Dr.Bob
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Just use it as an inert gas for blanketing reactions, and treat it like argon. Should work fine for that. Any other use is likely going to cost
more than a tank of argon. Or use it for mig welding. Nitrogen is cheap, so not worth trying to do that. It would be easier to buy liquid
nitrogen to condenser the argon out, if that is what you want, but still not very practical.
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SupaVillain
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| Quote: Originally posted by BromicAcid | | Quote: Originally posted by battoussai114 | | Liquefy the N2: Not particularly easy but if you get yourself a refrigerator pump or something along this lines you could build a cryo-refrigerator
based on the joule-thompson effect. N2 should be easier to liquefy, and as such, separate. |
cascade cooling would be the way to go, i.e., one compressor cools the next in line cools the next in-line etc. . |
Ultra low-temperature cascade refrigeration syste…: https://youtu.be/mzeRvdnIP-I
cascade cooling is awesome af. Prolly gonna make dis jaunt
[Edited on 23-7-2015 by SupaVillain]
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j_sum1
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Well, LN2 has been discussed here before. http://www.sciencemadness.org/talk/viewthread.php?tid=58712 and many similar threads I am sure.
This is the niftiest set-up that I have come across. Execution in this particular video is not that safe but the set-up is genius and looks to be
really convenient.
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MrHomeScientist
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If you want any quantity of pure argon, you'd need a mountain of magnesium to burn. It's 75% N<sub>2</sub>! If it was 1%
N<sub>2</sub> I could see that being more of an option.
This all sounds rather dangerous, impractical, and very expensive and difficult. Just buy an argon tank. I got a 40 ft<sup>3</sup> tank
from Airgas, no questions asked, for around $100. When it runs out, I can exchange the tank for a new full one for $20. I guarantee that is far less
expensive than some cobbled together LN2 machine that's liable to break any minute.
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SupaVillain
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Yes if my plasma applications for thin films truly need argon gas then i will just buy an argon cylinder. I was just going off on the tangent of these
cascade coolers because i had never heard of them before, i am surprised they are so cheap in comparison of other cryogenic approaches
[Edited on 23-7-2015 by SupaVillain]
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battoussai114
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| Quote: Originally posted by BromicAcid | | Quote: Originally posted by battoussai114 | | Liquefy the N2: Not particularly easy but if you get yourself a refrigerator pump or something along this lines you could build a cryo-refrigerator
based on the joule-thompson effect. N2 should be easier to liquefy, and as such, separate. |
Certainly an understatement, I mean, how often have you seen a refrigerator get down to -196C? There are threads on this on the forum but cascade
cooling would be the way to go, i.e., one compressor cools the next in line cools the next in-line etc. Unfortunately this also requires changing the
refrigerant in the compressors to things like ethane which is also no trivial matter. Even with your disclaimer, it is much easier said than done.
|
Pretty much everything is easier in the paper, and my way of seeing it is that if you're really willing it's always possible. This board is a nice
demonstration of this concept, after all, I've had a lot of people telling me that doing something was possible but wouldn't happen in a garage lab
and stuff along these lines.
Anyway the point here is that we are thinking of different techniques. In a joule Thomson machine you'd not be cooling a working gas and use it to
remove heat from the N2 Ar mixture. Instead you would exploit friction losses and other effects that make a non ideal gas cool during expansion(and
this gas would be the nitrogen argon mix) Then by repeated compression and expansion you should be able to achieve temperatures around 90K. It's
probably not a very effective technique, but it's still used in some air liquefaction equipment, and it's already been demonstrated to be possible in
a diy fashion by a guy known as imsmooth, later I'll try to find his page (I'm on my smartphone now)
[Edited on 24-7-2015 by battoussai114]
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battoussai114
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Here's ImSmooth video on his equipment, in the description there are links for resources like the plans and stuff.
https://www.youtube.com/watch?v=DaViMXLPkbA
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SupaVillain
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I've looked at tons of cascade cooling setups and I've already seen this diy homemade liquid nitrogen setup as well. I've concluded that imsmooth's
homemade liquid nitrogen setup is a lot cheaper and more straightforward than a cascade. I don't think it would take much more investment to collect
the oxygen coming from his nitrogen separator which would be another cool thing to have. His setup is the idea of having one big powerful compressor
instead of a series of smaller and weaker hermetic/in-line compressors with a number of refrigerants, such as in the cascade.
HOWEVER you dont need his big 4500 psi scuba compressor, that thing is for bringing stuff down to cryogenic temperatures, liquid air and
liquid nitrogen. You can get away with making good purity nitrogen just from the nitrogen separator he shows on his website. It's a PSA (pressure
swing adsorber) and to push air through it would make it a nitrogen generator.
[Edited on 11-8-2015 by SupaVillain]
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SupaVillain
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I've also found that they sell little nitrogen cartridges from online wine type stores. Just google "nitrogen cartridge" They seem great for
experiments but feasibility of production says get the 120 cu. ft. tank. If only they had these argon and xenon I would synthesize a hardon
[Edited on 11-8-2015 by SupaVillain]
turns out they have them for argon as well from the same wine supply shops but not xenon. 
[Edited on 11-8-2015 by SupaVillain]
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SupaVillain
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I'm starting to think that all you need for cryogenicity via joule expansion is an air compressor and this needle valve.... is this true? I think you
only need a big compressor if you want to have a large amount created, but then again that's governed by whatever amount of air can actually come out
of this needle valve, while it being... a "needle" valve... maybe being at such high psi and cfm then suddenly blasting in tiny amounts out of this
valve to atmospheric pressure is what makes it more possible.
http://homemadeliquidnitrogen.com/needle%20valve.html
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Hawkguy
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Lithium will react with the nitrogen, that's in my old 1921 Bloxam chemistry book for argon purification..
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SupaVillain
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YOOOOO
i found it
so basically an oxygen generator based off of a PSA/carbon molecular sieve will do the trick. Why? Because this molecular sieve is designed to adsorb
nitrogen instead of adsorbing oxygen, like they do in the nitrogen generators. In the data in the link below it shows that argon percentage increased,
as well as oxygen, when they compressed normal air into it. So if i send gas from a cylinder of 25%argon and 75%nitrogen, then the sieve will gather
all the nitrogen and come out of the waste end and the argon will come out alone on the product end. I can vacuum out the chamber to maintain the
purity of the cylinder tank of gas to the two new products, and send the nitrogen into a solar cell manufacturing process, while sending the argon to
a 488nm laser for bio fluorescence work and other vacuumed containers for storage before it's applications.
ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19920013240.pdf
Oh.
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