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Author Topic: Autoclave and pressure vessel discussion  (Read 151 times)

Shake

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Autoclave and pressure vessel discussion
« on: July 12, 2011, 03:22:44 AM »
There are tonnes of reactions that require increased pressures, 02 wackers like the SRV in that PET soda bottle is great as the bottle can hold 80psi quite easily.

The DMA 02 wacker requires temps of 80c and 6atm pressure, the pressure is ok for the sodabottle but it cant take the heat..

I would like people to bring forward ideas for pressure vessels that can be run hot (80-100c) and also take a decent amout of pressure 60 - 100 psi.

A couple i had were, if i were to coat the entire bottle in resin and fibreglass matting, all over it including the bottom, then fill it with boiling water, what would happen to the PET? would it melt? would the resin hold it? can thicker PET take 100c??

A mini portable cappacino steamer has an internal element, it heats water and builds up pressure, then there is a valve that releases the pressure to froth up milk ect. I have been thinking about this, fitting a tyre valve in the top of it, but i have heard palladium chloride reacts with the stainless steal in the vessel, i know PdCl2 stains stainless steel so there is something going on.. i have heard spiceboy had problems with fire extinguishers, the metal reacting with the palladium..

some refs say they used a "stainless steel autoclave" and others say they used a stainless autoclave with a teflon lining, or a glass inner.. Do all comercial science autoclavs have a lining?

Does anyone know how PdCl2 would affect aluminium? What metal will Pd not react with? surely they must teach these things in uni...

What about Dimethylacetamide or DMF in a PVC vessel? as it would be quite easy to get the parts for a pressure vessel from  the hardware, i just dont know if these solvents will destroy PVC, i think they might

soda stream bottles i guess would work but they are not so easy to fill with pure 02

« Last Edit: July 12, 2011, 03:26:27 AM by Shake »

Hawkwind

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Re: Autoclave and pressure vessel discussion
« Reply #1 on: July 12, 2011, 04:44:19 AM »
There are good chemists that wouldn't touch a homemade autoclave for some very good reasons.  Of course, there was a time when a great chemist like Roger Adams had to make his own starting from a pressure tank.  His original article may even be in the Rhodium archive.

I couldn't tell you if aluminum reacts with palladium chloride, but if it reacts with stainless I doubt the usual aluminum oxide coating will protect the aluminum.

If aluminum can be made suitable (is anodized aluminum less reactive?), perhaps an All American pressure sterilizer might be a good starting point for a low pressure, 1 atm. gauge autoclave.  Remove and replace the rubber blowout plug (fill or tap) and pressure relief valve and perhaps replace the bakelite handles on the locking lugs. Available from the gourmet, medicinal and psychedelic mushroom guy's company (edited:  I think it's an allowed source, but new rules, so I took the name out).

There's a nice hydrogenation vessel constructed by Magpie and discussion over at SM, look for the Homemade Autoclave thread in the Prepublication section.  That's where I would start.
« Last Edit: July 12, 2011, 07:14:16 AM by Hawkwind »

Vesp

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Re: Autoclave and pressure vessel discussion
« Reply #2 on: July 12, 2011, 08:10:46 AM »
80c of a PET Sodabottle?
Ever done this?

Have you ever once added boiling water to a PET bottle? Its a joke you'd even suggest such an idea let alone say also put it in with pressure.

Get a large metal pipe, attach a smaller metal pipe to it, and than add a weight on top of it that is the appropriate mass to hold the desired PSI for whatever reaction you plan to do with it... Essentially just create a pressure cooker -- same design, different weight to have a higher pressure...

Figure out some sort of safety release valve, or add additional weights that come off at different pressures... to inform you to stop heating...


« Last Edit: July 12, 2011, 08:13:52 AM by Vesp »
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Shake

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Re: Autoclave and pressure vessel discussion
« Reply #3 on: July 12, 2011, 10:02:46 AM »
Quote
80c of a PET Sodabottle?
Ever done this?

Have you ever once added boiling water to a PET bottle? Its a joke you'd even suggest such an idea let alone say also put it in with pressure.

Trust me, i have had plenty of soda bottle experience. It distorts with hot water i know. but notice how the thicker plastic around the lid is just fine?

My last experiment was a soda bottle wrapped in tape then wound top to bottom in nichrome wire then retaped, then connected to a laptop charger to run a current through the wire.. the bottle was then connected to a jigsaw shaker.. it ran smooth at about 60c under 50psi pure 02. Filled with DMF and PdCl2. DMF is know best for penetrating plastics..  Is that a joke?

So contrary to what you might think, im not talking out of my ass.

I never suggested putting it under pressure dude take it easy. It is a study on the properties of PET.
Have you ever coated something in fibreglass and resin?

the resin coated bottle would hold the PET in its shape, but would the PET melt? is the question.. Hot water distorts PET, but it does not necessarily 'melt it'

I could boil a PET bottle in water, it would not melt it away to liquid would it?. if its not melting it away, then under pressure in a resin coated bottle what would happen..

Making a metal vessel is easy, it is finding a metal that will not react with the Catalyst.

As for hawkwind, i believe the PdCl2 stains the stainless because it reacts with the chromium in the stainless steel, something that aluminium does not have.. Just like acetic acid is stored in aluminium vats, because it eats through steel..



« Last Edit: July 12, 2011, 10:26:29 AM by Shake »

aniracetam

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Re: Autoclave and pressure vessel discussion
« Reply #4 on: July 12, 2011, 01:56:57 PM »
hxxp://www.labsafety.com/refinfo/ezfacts/ezf213.htm
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Terror

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Re: Autoclave and pressure vessel discussion
« Reply #5 on: July 12, 2011, 01:59:52 PM »
Shake, was reading on this today and thinking about sending you a message.

I think those corneys are the way to go, as long as their not reactive. Or maybe run it at a lower temp with different (longer reaction) conditions.I didnt see anything in the lit. that suggested the reaction was temp bound, although maybe I missed it.

Maybe crome the inners of a corney, i mean heck, they are already set for pressure, has release valves, can't ask for much more!@
« Last Edit: July 12, 2011, 02:04:26 PM by Terror »
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Terror

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Re: Autoclave and pressure vessel discussion
« Reply #6 on: July 12, 2011, 02:01:56 PM »
aniracetam - I was thinking about some sort of PTFE buckets with an element installed.. Who knows how that would work in ghetto prep but those buckets are cheep-cheep
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n.snostorm

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Re: Autoclave and pressure vessel discussion
« Reply #7 on: July 12, 2011, 08:22:26 PM »
What about modified fire extinguisher, those with round bottom. Like in cars.
It's easily immersed in oil/water bath or nickel-chrome heating wire could be wound around it.

jon

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Re: Autoclave and pressure vessel discussion
« Reply #8 on: July 12, 2011, 08:38:23 PM »
if you want to make a fire extinguisher chemically resistant you can always coat it in xylan 1004 (teflon)

Shake

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Re: Autoclave and pressure vessel discussion
« Reply #9 on: July 12, 2011, 11:32:44 PM »
aniracetam that link was perfect!

yeah teflon coating would be ideal, you can get it in a can in america i think..

JustDreaming

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Re: Autoclave and pressure vessel discussion
« Reply #10 on: July 13, 2011, 05:15:27 PM »
I remember reading champagne bottles can hold an internal pressure of 90-100psi. Not sure if this is something of value to this discussion or not, but it sounds a whole lot better then using pop bottles.
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Shake

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Re: Autoclave and pressure vessel discussion
« Reply #11 on: July 13, 2011, 10:10:06 PM »
jon knows all about champagne bottles, ;) BOOM..  i could reinforce one with resin and fibreglass but how could a tyre valve be fitted in it? Also the base is not flat, it is a dome, and the stirbar will not spin on it

So far the easiest seems like hand held pumpable a weed sprayer, drill a hole, fit a tyre valve..

Wrap it top to bottom in aluminium tape for heat dispursion, then wrap it in some type of heat proof tape, before wraping the whole thing top to bottom in nichrome wire and cover with resin.

If the wire is able to touch the aluminium tape it will bridge the current and the resistance wire wont heat up.

Finally wrap it in tape again so its not too hot to hold, connect the wire to a charger or powersource that will hold the contents of the bottle at 60-80c,

I have a question about safety here, the flash point of the solvent is actually 80c. The refs warn about this, but they still run the reactions at 100c using the solvent..

is there much to be worried about here?

car battery trickle charger might be the go, but it will depend on how much wire used..
« Last Edit: July 13, 2011, 10:13:24 PM by Shake »
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