Sciencemadness Discussion Board

Stainless Steel Reaction Vessels

dettoo456 - 31-1-2024 at 19:37

Does anyone use or have experience using stainless steel reaction vessels instead of glass? Obviously it’s used industrially over glass (or with in glass-lined vessels) but I haven’t seen much amateur use. Even plastic bottles and weird stuff like old fire hydrants seem more commonly used than normal stainless steel. It seems cheap (when bought used), nonmagnetic, less fragile, and pretty corrosion resistant except against halogens. Borosilicate is universally resistant of course, but in some procedure like a nitration, extraction, reduction, or generally anything organic, 304 SS seems like it’d be plainly better to work with.

Is there something obvious I missed about it?

[Edited on 1-2-2024 by dettoo456]

Sulaiman - 31-1-2024 at 23:59

The reason that I use mostly glass is....
I can watch what happens.
Interesting, educational, and I get some warning of impending disasters.
And it's cute ;)

PS as a boy dabbling with chemistry I wanted jointed glassware,
now, as a big boy, I can afford it.
But I may have over-compensated for my unfulfilled boyhood desires ;)

[Edited on 1-2-2024 by Sulaiman]

Rainwater - 1-2-2024 at 01:37

Quote: Originally posted by Sulaiman  
But I may have over-compensated for my unfulfilled boyhood desires ;
your not alone.


I seen someone post a while back about some ss shot glasses. these have worked great for decomposition reactions for me. And are affordable.
They didnt hold up to well for molten salt(nacl,cacl mix) electrolysis because the outside started corroded due to air exposure, worked good as a cathode and i did recover some sodium.

For molten or boiling down group 1 salts, that normally destroy glass, they work as expected, slight discoloration of the salt from chrome contamination, but that is acceptable for my purpose. They can not be used with strong acids, so nitric and sulfuric are out. And i destroyed one boiling down sodium acetate from solution containing a slight excess of vinegar
Edit:
This 30mL shotglass would work better than the stainless steel ones

[Edited on 1-2-2024 by Rainwater]

charley1957 - 1-2-2024 at 05:42

I use stainless if I need to utilize really high temperatures, but often get a contamination from it as Rainwater noted. I try to use glass whenever possible, but I do have a few assorted sizes of stainless bowls and cups for those times when I need the heat resistance.

SnailsAttack - 15-3-2024 at 16:50

I have a stainless steel beaker. It's only a year old but it looks like shit and I barely even use it.

IMG_7677.jpg - 121kB IMG_7678.jpg - 103kB

I don't think I've even put a chloride salt in this thing and the interior's already completely dull. A fair amount of rust rubs off when wiped with a paper towel, but nothing too crazy, to be fair.

I'd say it's probably useful for handling wet alkalis and maybe organics or fairly dry salts, but never wet chlorides or anything even remotely acidic.

The nice thing about stainless steel is you don't have to worry about it randomly imploding on the stovetop the way you do with glassware; this thing is virtually indestructible. Too bad it still tends to chip and flake off as it rusts.

SnailsAttack - 15-3-2024 at 16:53

Quote: Originally posted by Rainwater  
ss shot glasses. these have worked great for decomposition reactions for me. And are affordable.

Oh these are perfect, I've been having to choose between the metal beaker I posted and a teeny little 30 mL cocktail shaker cap which is about ready to crumble to dust.

Keras - 15-3-2024 at 23:55

I was looking at some point to some sort of stainless steel round bottom flask to perform the thermal decarboxylation of sodium benzoate to benzene, which was a crazy idea (the flask, not the reaction)

You can find bottles with GL45 threading, but they’re super expensive.

And in any case, it’s impossible to fit steel to glass because of the difference in thermal expansion coefficients…


zed - 20-3-2024 at 17:15

Umm. Decarboxylation of Sodium Benzoate? Guys often use "tin" cans for this type reaction. Cheap! Easily replaceable! Empty (handheld) propane torch cylinders might suffice. When they invariably corrode away; it is no big loss.

mr_bovinejony - 20-3-2024 at 18:58

Recently I found a stainless steel pepper grinder that last 1 run at 900c with some ferrocyanide using a small clay pot to close the bottom. Is there really no way besides welding to seal the threads of a stainless steel pipe and cap to withstand such high temperatures? Refractory cement may work but having the chisel that crap off every time you open the cap would be a pain

Kf flanges can be used to go from steel to glass the connection would have to be far enough to be cool

BVV Stainless Steel KF-25 x Glass Jointed Adapter-24/40 https://a.co/d/iKBOr03

[Edited on 21-3-2024 by mr_bovinejony]

Keras - 21-3-2024 at 04:50

Quote: Originally posted by zed  
Umm. Decarboxylation of Sodium Benzoate? Guys often use "tin" cans for this type reaction. Cheap! Easily replaceable! Empty (handheld) propane torch cylinders might suffice. When they invariably corrode away; it is no big loss.


Yes, I know. I just happen to have none really available at hand at the time, and I was looking for a more ‘durable’ device.

Mateo_swe - 10-4-2024 at 01:24

There are these "Hydrothermal Autoclave Reactor" made of stainless steel that is used for chemical reactions.
They are completely sealed and made up to withstand the pressures developing inside.
They usually have a PTFE jar inside that you put the reagents in and all this goes inside the SS vessel.
They are really nice but somewhat expensive.
One can use these instead of an autoclave in some applications.
But Borosilicate glass is easier and better for most situations.


SS rector.jpg - 110kB

Dr.Bob - 10-4-2024 at 13:59

I have used these "bomb" type reactors occasionally for years, always behind a shield, hence the name...

They are OK, but you can't see the reaction, it is hard to heat them in a simple manner, unless you buy a special heating mantle and controller rated to high temps, and they corrode eventually. And the liners often warp or bend so that they are hard to use. But I have done reactions at many atm in them. I usually start moderate (1/2 of rated pressure), then work my way up slowly. If your reaction generates a gas, like de-Boc'ing an amine, they can be a mess, and build up pressure very fast once a reaction starts, or if it is auto-catalytic. Again, use a shield...

For slightly high pressure reactions, I prefer glass pressure tubes (like from Ace) or even better, disposable microwave tubes with crimp caps, like CEM or Biotage has used. Both have fancier caps now, but the old crimp top ones were the bomb... I often use them outside of a microwave, in oil baths or other heating methods, again, always behind a shield, just in case. I could do 140C reactions in EtOH and isoPrOH with those, and similar reactions. Much easier than setting up a reflux condenser, and reactions go faster at higher temps. But always some danger. Maybe that is why people like them. For low pressure reactions, I often use septa top vials and heat just to the BP, which works fine, and normally does not build up enough pressure to pop the septa top, but that acts as a pressure limiting device as well.

I have only blown up a few vials in the microwave or vials. But use some sense, heating K2CO3 in acid in a sealed tube is not a good idea, and many other things I have seen people do. Heating organics in air or oxygen also is not so wise... Best to blow out with nitrogen.

ManyInterests - 10-4-2024 at 14:14

I'm not sure about reaction vessels, but I did make ammonium nitrate from calcium nitrate (via ammonium carbonate) in a copper lined dutch oven without issue. Did the same with my stainless steel dutch oven.

Now I only use that to boil down my nitrates out of solution. I never saw any degradation of my product as a result.

Quote:
I have only blown up a few vials in the microwave or vials. But use some sense, heating K2CO3 in acid in a sealed tube is not a good idea, and many other things I have seen people do. Heating organics in air or oxygen also is not so wise... Best to blow out with nitrogen.


Yeah don't do that. I tried to heat up KNO3 in water in my microwave and... yeah, I had a bad feeling and I stopped before anything happened.

BromicAcid - 10-4-2024 at 16:13

My work has been trying to swap over to stainless flasks for use with pyrophorics for safety sake. They are shaped just like a regular 22L, 50 L, 72L flask but have KF glassware joints which are a kind of flat face joint with a gasket and clamp. We have regular flasks with the same joints too. One of the necks usually has a glass viewing window installed and if there is a free joint after everything else is hooked up a second will usually be setup with a glass window so you can shine the flashlight through that one and look through the other as a view port. They work fine, not sure I've noticed better thermal conductivity despite the fact that you would expect it.

dettoo456 - 11-4-2024 at 07:08

Quote: Originally posted by BromicAcid  
My work has been trying to swap over to stainless flasks for use with pyrophorics for safety sake. They are shaped just like a regular 22L, 50 L, 72L flask but have KF glassware joints which are a kind of flat face joint with a gasket and clamp. We have regular flasks with the same joints too. One of the necks usually has a glass viewing window installed and if there is a free joint after everything else is hooked up a second will usually be setup with a glass window so you can shine the flashlight through that one and look through the other as a view port. They work fine, not sure I've noticed better thermal conductivity despite the fact that you would expect it.



Do you know if they have pressure relief valves (or purges for pyrophorics) on all those steel reactors too?

Especially if using glass pressure vessels w/ Ace threads, taking up a joint with a relief valve seems like a no-brainer, at least for peace of mind.

BromicAcid - 11-4-2024 at 10:01

Quote: Originally posted by dettoo456  

Do you know if they have pressure relief valves (or purges for pyrophorics) on all those steel reactors too?

Especially if using glass pressure vessels w/ Ace threads, taking up a joint with a relief valve seems like a no-brainer, at least for peace of mind.


Yeah, one of the necks is a burst disk, they're appropriately sized by the engineers based on the size of the vessel and they blow out into an inerted container.

Grizli7 - 16-4-2024 at 08:08

First, you need to decide on the reactions that you will carry out and only then select/make stainless steel equipment. Glass is glass. Stainless steel is stainless steel.