zig (Stranger)
02-26-02 10:38
No 273851
      MeNH2 gascilinder  Bookmark   

In a very interesting dream someone was able to buy a couple of small gas cilinders. The little cilinders are app. 45 cm in length and 7 cm width. The inscription says: 250 bar, 0.405 l, 0.207 kg anhydrous methylamine. The cilinders are non-refillable. They have only one crane. How does someone use this kind of cilinders? How can you get the MeNH2 in flask as a liquid? What kind of pressure valve's do you have to use? Like in some post were they talk about elve's...  tongue.
(Old P2P Cook)
02-26-02 11:40
No 273881
      Re: MeNH2 gascilinder  Bookmark   

The little cilinders are app. 45 cm in length and 7 cm width.
Sounds like what are commonly refered to as "lecture bottles".

They have only one crane. How does someone use this kind of cilinders?
So the cylinders have one valve on them but this is mostly just an on/off valve. You need to find some sort of multi-turn valve to use as a regulating valve. You will need to know what type of thread is on the cylinder outlet so that you can get another valve with the same thread. The valve should probably NOT be brass as the metylamine may attack brass. Stainless steel or carbon steel should be suitable.

How can you get the MeNH2 in flask as a liquid?
Another thing you would like to know is if the cylinders have an "eductor tube", this is a tube inside the cylinder that runs from the cylinder valve to the bottom of the cylinder. The purpose of the eductor tube is to make it easy to get liquid out of the bottle.

You may be just as well off if you have cylinders without an eductor tube. Then you can bubble gaseous methylamine into cold methanol to make a 10% solution. Easier to handle than liquid methylamine.
Edit LT/: do not use gaseous methylamine to bubble, much faster: use the lecture bottle (only if they have no eductor tube!) in an upside down position, with the valve down and the bottom up. That way, a thick rubber hose clamped on the valve outlet will transport liquid methylamine directly in the ice cold methanol, situated on a digital balance, so you can close the valve when 10% more weight is read from the balance. Be carefull not to overheat the methylamine/methanol mix by letting too long methylamine in, so then cool the mix again in a freezer and repeat the procedure untill 10% extra weight is measured. LT/
03-01-02 09:55
No 275374
      Re: MeNH2 gascilinder  Bookmark   

Thanks for your reply! After some searching somebody else got a pressure regulator. For the vac pumps someone else uses black hose; is this type of rubber hose suitable for MeNH2? And to be sure if there is an eductor tube in it, because the supplier couldn't anwser that question, I'll hold the lecture bottle in upside down position. When soemone else opens the bottle and a fluid comes out, the bottle hasn't got an e. t., if a gas comes out there is an e.t.
03-06-02 02:09
No 277754
      Re: MeNH2 gascilinder  Bookmark   

Pressure regulators are good when dealing with gas.  But as far as SWIM understands, it can be bad for liquid gas to get into a gas regulator. Swim doesnt know if this is relevant to MeAm, and it may depend upon the type of regulator.

However if the bottles are to be used for dispensing liquid, then surely all that is needed is a stainless needle valve and appropriate adapters (or one can always get a couple of stainless fittings welded together wink)


When the day is bad,and life's a curse
CHEER UP!!! Tomorrow may be Worse!!
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(Hive Bee)
03-06-02 07:50
No 277866
      Re: MeNH2 gascilinder  Bookmark   

Gasseous methlyamine works great for hydrogenations with rainey nickel Catalyst.