Steam Distillation

[diogenes]

Hi, sorry for another question, just want to clarify what you have said. Steam distillation is recommended under vacuum, so that the temperature is even lower and no oxidation occurs, right? Also in the second post you advice to go 1 drop per second, so about 3ml/minute, otherwise some oil will also come through with the steam. Is this not the main goal of steam distillation, I mean we are trying to get the pue prduct (oil) to come over to the reveiving flask. What am i getttig wrong? thank you

 

[G.Patton]

Hi, sorry for another question, just want to clarify what you have said. Steam distillation is recommended under vacuum, so that the temperature is even lower and no oxidation occurs, right? Also in the second post you advice to go 1 drop per second, so about 3ml/minute, otherwise some oil will also come through with the steam. Is this not the main goal of steam distillation, I mean we are trying to get the pue prduct (oil) to come over to the reveiving flask. What am i getttig wrong? thank you

diogenes

oil will also come through with the steam

Which oil do you mean? Amphetamine/meth? Steam distillation is assumed that you distill them as azeotropic mixture.

 

[G.Patton]

In theory boiling point drops to below 100C, right? I have done this without vacuum and the boiling point kept at 98-99. The amph base-water azeotrope has lower boiling point than water alone. On the other hand the small change in boiling point makes it impossible to distinguish between different oils.
e.g. https://chem.libretexts.org/Bookshe...ria/Immiscible_Liquids_and_Steam_Distillation

What I don`t understand is why most sources generate steam in a separate flask. Is it not easier to just put the water and the oil together in one flask, stir and distill? This can be supplemented by an addition funnel to replace water if it runs out while there is still some oil left.

diogenesHi, thank you for interesting theory link. An answer to your question is in a linked topic:

Obviously if you have two immiscible liquids in a closed flask and keep everything still, the vapor pressure you measure will simply be the vapor pressure of the one which is floating on top. There is no way that the bottom liquid can turn to vapor. The top one is sealing it in.

What do you want to say, I don't understand your idea? Side products will have same bp shift with steam. Hence you can separate them by this distillation from amine.

On the other hand the small change in boiling point makes it impossible to distinguish between different oils.

P.S. @KokosDreams and @ImOutAlso You will be interested to read this topic (link above).

 

[KokosDreams]

Hi, thank you for interesting theory link. An answer to your question is in a linked topic:

What do you want to say, I don't understand your idea? Side products will have same bp shift with steam. Hence you can separate them by this distillation from amine.


P.S. @KokosDreams and @ImOutAlso You will be interested to read this topic (link above).

G.PattonThanks brother! Saved this to my library

 

[diogenes]

Hi, thank you for interesting theory link. An answer to your question is in a linked topic:

What do you want to say, I don't understand your idea? Side products will have same bp shift with steam. Hence you can separate them by this distillation from amine.


P.S. @KokosDreams and @ImOutAlso You will be interested to read this topic (link above).

G.PattonThe link recommends vigorous stirring to keep the oil/water mix `swirling` continuously, which will prevent the oil from `locking` the water underneath.

In this way the vapour pressure of the water, which is (roughly) 1 bar = 760Hgmm at 100C. Now the overall vapour pressure of your`swirling` mixture will be the sum of the vapour pressure of the oil and water. The oil`s vapour pressure at 100C is nowhere near 760Hgmm so will contribute very little to the sum, and only reduce the boiling point a tiny bit. So in case there is an unwanted, but volatile component in your oil, with similar boiling point as your product, it will be difficult to tell when your desired product and when this undesired product is coming over to the collection flask.

E.g. the vapour pressure of benzaldehyde is 0.074bar at 97C water`s vapour pressure is 0.91 so the sum is just short of 1 bar, and benzaldehyde will distill with the water at 98C. I haven`t found a calculator for amphetamine base vapour pressure, but it is lower than benzadehyde because it`s boiling point is higher and its weight is higher as well. So it will boil between 98 and 100C. There are a lot of factors, such as altitude etc. and these are just estimated values, but the point is that most molecules we are dealing with will boil with water/steam in a narrow temperature range and it not possible to tell what is coming over based on temperature. The steam temperature difference will be minuscule even if the compounds` boiling points are very different e.g. benzaldehyde and methamphetamine. With steam distillation it is only possible to separate the volatile components from the non-volatile `pollutions` in your oil. (Which is what we need as most of the volatile components is our product.)

 

[Lordoftheshard]

I steam distill.my meth freebase it's the proper Aussie way of making meth buy I'll explain and show the Aussie.variation of steam distilling

Here in Australia the most popular way of making meth is via hypophosphorous acid 50% or stronger anything less than 50 % it won't convert that psuedo or ephedrine to meth so before you start anything a refractometer is needed to check the strength of your hypo acid

Now let's fast forward we have refluxed reaction mix for 4 hours psuedo hypo acid and iodine and now we want our meth freebase to set up for steam distillation you will need a pressure cooker with PTFE hosing and a glass tube or straw attached at the end of f that hosing
You want to use a 3neck angled rbf for this the way your going to get your steam into the flask is threw the side neck a rubber bung with a hole drilled in the middle of it to fit the the glass stem I I spoke of earlier.threw it and into the flask all the way threw form about an inch to 2 off the bottom of your
flask
Now this should have been measured and s o forth before you even start the synth the rule of thumb here 1kg of of pseudo used 2kg of dry caustic and you might ask why dry caustic because if you used the normal 20% caustic route the steam your pumping in will lower the pH under 13' and you won't get all your FB oil out
What about caustic lock or lye lock I hear you say well thats what the steamer is for it breaks everything down so don't fear
Your pressure cooker should on top of a gas burner switch the burner on when you start to add the caustic to the flask this is done threw a powder funnel in the side neck add a little bit at a time stopper the powder funnel straight away shit smoke will build up in the flask over the recovery bend and half way down the condenser wait till All the white smoke has gone back into the flask before adding more caustic farst forward and that flask is hot and sweating think it's going to explode nthr n all if a sudden the caustic isn't reacting with the reaction miix pour what you have left of the caustic into the flask get you r glass tube with rubber bung and were you were putting the caustic i .in put the glass tube and rubber Bung inti the side neck now adjust your pressure of your steam with the gas burner we want it breaking down the caustic not bringing anything over yet

Once half the caustic is broken down adjust your gas burner so the vapour pressure does not go down further than a quarter of fthe the way down the condenser
FB oil and water will Go down into your receiving beaker once all the FB oil had been collect place that contents of the beaker into a sep funnel let seperate collect your FB oil and discard you caustic water

 

[Botsauto-Dutchland]

Cant realy see or find it here but steam distilation works only good when using a seperate boiling flask or controllable steam machine, and blow steam true the boiling flask, wiich is heated to.
After this a vacuum distillation can be done (for the dot on the I.) dont know to say it in engelishj

 

[Lordoftheshard 2]

Cant realy see or find it here but steam distilation works only good when using a seperate boiling flask or controllable steam machine, and blow steam true the boiling flask, wiich is heated to.
After this a vacuum distillation can be done (for the dot on the I.) dont know to say it in engelishj

Botsauto-DutchlandNo need for vacuum distillation of you want to be anal run it's three the steamer again