Steam distillation:
Distillation of a pair of immiscible Liquids:
When water and a immiscible substance are heated,
boiling commences when the total vapour pressure is equal to the external atmospheric pressure.
Assuming that Dalton's law of partial pressures holds,
each componenent will be contributing the pressure of vapour which it alone would be exerting at the boiling point of the mixture.
Thus is Pw and Pa are the vapour pressures of water and the immiscible liquid then at the boiling point
Pw + Pa + 760mm
and the composiion of the vapour is
Nw/Na = Pw/Pa
where Nw and Na are the numbers of moles of water and the liquid in a given volume of vapour.
But Nw = Ww/18 and Na = Wa/Ma where W is he weight of the substance in the vapour and M is the Molecular weight.
Hence Ww/Wa=18Nw/MaNa = 18Pw/MaPa
and the weights of the two liquids collecing in the distilate are directly proportional to their vapour pressures and their molecular weights.
The advantage of steam distiallation can be immediately seen in the the molecular weight of water is low compared with those of liquids which may be steam distilled
An example of steam distillation is iodobenzene.at the boiling poin of he mixture, 98.2
the vapour pressure of waer Pw is 712mm and that of iodobenzene Pa is 48mm. Subsituting these figures and
the molecular weight of iodobenzene, 204, into the equation, we have
Ww/Wa=18x712/204x48=13.1/10
Thus, for every 13.1 g of waer colleceed, 10g of iodobenzene are obtained.
Distillation with superheaed Steam
Consideration of equation above indicates that the proportion of the higher boiling point componenet in the steam distillate can be raised by increasing the vapour pressure of the component relative to water,.
This can be achieved by superheating the steam
The effect of super heated steam may be illustrated by reference to benzaldehyde, which boils at 178c at 760mm. It distills with steam at 97.9c(Pw is 703.5mm and Pa
is 56.5mm)
and the distillate contains 32.1 percent of benzaldehyde by weight.If one employs steam superheated to 133c, the vapour pressure of benzaldehyde (interpolated from the boiling point-pressure curve)
is 220mm: hence Pw is 540mm, Pa is 220mm, Ma is 106 and
Ww/Wa=540x18/220x106=41.7/100
i.e. the distillate contains 70.6 percent of benzaldehyde by weight, this compares nicely with 31.6 percent with steam at 100c and one atmosphere.
The use of superheated steam has the advantage that less condensation takes place theus obviating the use of supplimentary heat in the vessel containg the substance;
beyong this no advantage ovewr stream used underordinary
pressure will result so long as condensed water is present. If all condensation of the steam is prevented(eg surrounding the flask by a bath of liquid at the same temp as the super heated steam), the higher temp of the superheated steam will result in an increase in the proportion of he higher boiling point component of the distilate.
In practice superheated steam is genberally employed for substances with a low vapour pressure(<1mm) a 100(The mdp2p ketone!).The upper limit of temp will of course be controlled by the stability of the compound.
Notes on Purification by Crystallisation of Organic substances.(vogels)
1) scratching the inside of the beaker
2) innoculation with a seed crystal, created by freezing a .1ml of the oil of a large surface area
3)cooling the solution
4) Adding lumps of co2
5) Or just do as i did and leave in a ice chest, freeze the fuck out of it, let it warm up for a bit untill crystals form
from the scratching method, then re freezing,.
Preface: 5/08/2002
Yes, I did it, Lil ol' hellman, I think it was prettyobvious after all these years of watching and lurking around that maybee nobody believed this could be done, or maybee ..ahh who cares here it is,.
This is for you all to enjoy,
Whether drugs are the tools to the evolution of man, or to hide our earth bound sadness,
it is for you to decide and moderate
If you can do this(moderate drugs) then you have won the battle, As what is to follow is the final piece to the puzzle,.
From Sassafras to Mdma.hcl without vacuum distillation
My journey began with chinese Sas, the clear waterwhite variety,
from this I obtained sizeable crystals through freezing,.From this I followed the benzoquinone(from hydro+h202+i2) wacker,.
Work up was standard and the post reaction mix was washed wih more care than ususal,.
I assembled a $20/20l stainless seel reaction vessel(Big Cooking Pot), loaded it with 10
litres of water,And placed it on the stove. To the small hole on the top of the airtight lid,
I attached a run of platic tube which ran to the floor, into a 5 liter pyrex bowl resting in
cool water.
Into the pot i dumped the 100 ml or so of dirty ketone,.Resealed and started the heating, until
a vigourous boil was obtained,.
Slowly, the distillation started and distillate dripped at about 3 or 4 drops per second into the
recieving flask.(I could have increased this)
Periodically i would check the water level, and adjust as necessary to keep the pot as full as possible wih water to minimise condensation,.
My fascination quickly eluded me, retopped the water level, and continued to hang anxiously
around for the next 8 hours,.
After a total of 12 or so hours I could see what i thought was about 60 or 70 ml of clear oil
floating beautifully in the reciever bowl.
Yes chromic you are about right in your calculation, approx 1-2 oil per 100ml water,.
I am tired now, but it was breathtaking as it was a beautiful sight,.
-In hindsight I believe that there was no need to crystalize the mdp2p, I believe its purity was sufficient,.
But i had to try it, next time I wont bother,.
I created a cooling chest by slowly heating a drinking glass 500ml in the oven to about 300c(this can be done, the trick is o do it slowly)
With this heated glass I submerged it ino a 20cm CUBED BLOCK of polystyrene(I was going to ozonate this styrene, but I will leave that to another day)
Into the glass which had cooled-(smile), I poured my Co2/acetone/salt/ slurry, and ino that i placed
my testube containing roughly 50ml clear as water Mdp2p,.
Being not a professional in crystallizing, It took me a while to get a seed crystal to start,.
I furiuosly went through vogels, and realized that letting the substance warm just a little, then scratching it with a glass rod produced the seed that i was after,.
Back into the ice chest it went, and back into the freezer,.
And with 2 hours after that the whole testube was a crystalline solid, WOW,.(or for you american dudes-Neat-)
I let it warm jst a bit drained the oil and refroze,.
So, Yes you can crystalize Mdp2p, but after steam distillation, I don't believe that it really makes that much difference.
I aminated the crystal and got 9g from 10g-It was the same yield as when Vacuum is used
I aminated the steam distilled oil,. I got 8.2g from 10g oil.
But I think the point here is that I have crap technique,.
The yield here is not what is the interesting bit,.
-it is thae fact that this operation was not babysitted,.
-It could be ran unnatended in a remote location, done in multiple reaction vessels, I am am talking like 50 small vessels, all fed by one steam generator,.
Then you are talking big scale,.
think abou that, really think about it,.
In hindsight i could have used superheated steam,to further increase the ratio of ketone to water,.
I honestly believe that you could process say 1 litre of mdp2p remotely
with multiple vessels, in say a week or maybee less, I haven't done the math, but I am sure one of
you guys can,.
Use superheated steam,-
you see I modified the reaction vession by making the whole thing kinda of in situ,.
Normally you would pump steam into the reaction vessel, I created the steam in-situ,.
But Your reacion vessels could be like 100 testubes bound together in a matrix, all with 2 holed pluro
stoppers with say one litre of dirty ketone spread amongst each one, all fed by the one steam generator
With the run off all going into a centralized recieving flask,.
Hellman's Matrix, 0 Yeah I like that,.
And you know what, it will work,.
Imagination, fuck i can really feel it,.
Good luck everyone,.
-you see ladies and gentlebees, fear really can be over run by logic, which really is just a little bit of wisdom seeded byimagination.
Now you should never get caught right?
-imagine having your apparatus in the forest, or in the country,
Just like cooking damper, you could come back after a week to find 1 litre of the cleanest mdp2p sitting in the recieving flask, buried below
the ground,
I would like to thank Placebo for the Hydroquinone Source
Osmium for his Logic behind muliple batches vs increased size labware
Methyl Man, An old Friend, And Kapten, Baalchemist, chromic who have powered the dreams to push the envelope and stand on the shoulders and see further into the dark.
And a special respectful hello to rhodium for archiving the ingredients to this ordered madness.
Caveat Emptor
The end.
IQ is the rate of logic, as Wisdom increases logic, fear & compromise decrease to reveal objectivity
