Sciencemadness Discussion Board - Need Help with Fractional Distillation of Camphor oil

Need Help with Fractional Distillation of Camphor oil

ScienceNoob - 3-6-2012 at 12:35

I am currently distilling a oil which is currently boiling at 170C. Here is the problem I have been running this distillation for over 13 hours the abstract says that it should only take 4 hours. I recently ran a test run with tap water using my water aspirator to create a vaccum. I found it odd that even with the vaccum attached that the BP was 100C this seems odd because this is what it should boil at at normal pressure please correct me if I'm wrong. I was expecting my thermometer to get a reading by now and to have my distillate come over to the receiving flask by now. I will post pictures if someone gets n here to help.

Hexavalent - 3-6-2012 at 13:05

The BP of water will vary with atmospheric pressure - could be 97*C in some places, maybe even 102*C in others.

Silly question, but are you certain the vacuum hose is actually attached to the apparatus?

Are you using a vacuum trap between the flask and pump/aspirator? What sort of water pressure is running through the aspirator?

Post the pictures and add more detail about your situation and we'll try and help.

[Edited on 3-6-2012 by Hexavalent]

ScienceNoob - 3-6-2012 at 13:08

TY TY TY stay there please I will post pictures right now to show you what i'm working with just hang tight please I beg you

Hexavalent - 3-6-2012 at 13:11

I will, as long as you discontinue your practice of asking in other, unrelated threads for help with this question.

This should be in Beginnings, I'll inform the mods so that they can shift it.

ScienceNoob - 3-6-2012 at 13:12

I apologize I'm just desperate

Hexavalent - 3-6-2012 at 13:19

Patience is key to chemistry. If I were you, I'd switch everything off now and try again tomorrow or later, depending on where you are in the world (time zone areas), e.g. in the UK ATM it's 22:20 and getting quite late. Concentration will rapidly decrease and you will likely, under this additional stress of yours, break something or hurt yourself; trust me, my 2L quickfit flask full of sodium hypochlorite knew this.

ScienceNoob - 3-6-2012 at 13:20

Well i can't find my flash drive atm but yes I am sure the hoses are connected properly the condenser is filling nicely and the outlet is making a small little tornado where the water goes back into the tub please wait just a little longer I will have photos soon.

Hexavalent - 3-6-2012 at 13:22

How much oil are you distilling and how long is the fractionating column you are using?

Little amount of oil and large column = no brainer.

How do you know BTW it's boiling at 170*C? Did you look this value up or measure it yourself, e.g. with an infrared thermometer or something?

[Edited on 3-6-2012 by Hexavalent]

ScienceNoob - 3-6-2012 at 13:29

I'm fine ready to go it's only 5:00 pm where I am at plus I have insomnia

posting some pictures now

Hexavalent - 3-6-2012 at 13:31

How are you actually heating the oil?

I can't see in the photos.

ScienceNoob - 3-6-2012 at 13:33

Yes I have an infra red thermometer but I know that the real BP is when it reaches the 3 way adapter which leads me to believe something is wrong with the aspirator.. I got it to work before with a 500mm vigerux column but I broke it being a noob trying to unpack with a small coat hanger. Feel free to call me dumb because I smacked myself literally could of just used muratic acid. Also I am distilling roughly 200 ML of the Oil at the moment. Do you think using a larger flask would be better I have a 1000ML RBFlask as well as a 3 neck RBFlask. I don't think its the flask but I'm just reaching out at any straw possible at this point

ScienceNoob - 3-6-2012 at 13:37

yes I am using an oil bath peanut oil since it retains heat nicely and doesn't catch on fire from what I have read until it reaches above 200C

ScienceNoob - 3-6-2012 at 13:39

Also to answer your other question I am using a 200MM vigerux for my column

Hexavalent - 3-6-2012 at 13:40

I would use a 500ml flask, if you have one.

Too big a flask will cause problems with heating, splashing and maybe bumping...always use some boiling stones or a stir bar.
Too small a flask will cause problems with filling the excess headroom with vapours.

1.. If it's reaching the 3-way adapter, what's the problem?
3. Do you have a vacuum gauge? If so, measure the vacuum produced and compare it with the expected boiling point at THAT negative pressure level.
4. Does the aspirator have fluctuations in the vacuum it provides?
5. What flowrate of water is going through said aspirator?
6. Add some marshmallows to a sealed vacuum flask and quickly apply a vacuum and release it. Does anything happen to them?
7. Is the vacuum tubing collapsing maybe under the vacuum?

Also, please use the edit feature to add more information to a single post as opposed to posting sequentially.

Edited to remove questions answered whilst I was typing this post.

[Edited on 3-6-2012 by Hexavalent]

ScienceNoob - 3-6-2012 at 13:46

I am using a 250RB Flask for the reaction vessel.

1. How are you heating the oil? Peanut Oil Using Heating plate with magnetic stirring
2. If it's reaching the 3-way adapter, what's the problem? It is not reaching the 3 way adapter
3. Do you have a vacuum gauge? If so, measure the vacuum produced and compare it with the expected boiling point at THAT negative pressure level. Nope I don't have one need to get one
4. Does the aspirator have fluctuations in the vacuum it provides? No this is a pond pump just drop it in the water and it does its thing
5. What flowrate of water is going through said aspirator? It seems to give a pretty good flow rate I can't really give a measurement because I'm not sure how to test that.
6. Add some marshmallows to a sealed vacuum flask and quickly apply a vacuum and release it. Does anything happen to them? I will have to try this
7. Is the vacuum tubing collapsing maybe under the vacuum?

Hexavalent - 3-6-2012 at 13:52

1. I would suggest using a bigger flask.

2. My mistake, sorry I misread one of your posts. Have you tried warming the oustide of the column with a hot air gun or something? It looks like you are performing this outside, and if its a windy day even with insulation the column can cool quickly. Can you see a reflux effect of the boiling oil on the base of the fractionating column?

4. Are you using a water aspirator for the vacuum? How does a pond pump create a vacuum?

5. High pressure? Low pressure? Trickle?

6. Just to test the vacuum.

7. Collapsed tubing caused by thin-walled hose is a bad thing for containing a vacuum. Shoot us an image of the aspirator/vacuum pump if you can, in operation, with the tubing you use. What is the wall thickness of this tubing?

ScienceNoob - 3-6-2012 at 14:05

Ok I will post pics here in a minuet.. I think it may be the tubing here is the link http://www.hometrainingtools.com/rubber-tubing-5-16-x-10/p/C...

The pressure is I would say low pressure like turning a faucet on really low... and II am now sure how the pond pump creates vaccum I was just going by what the procedure recommended. Also, I can see the reflux swirling around mixing with larger pools of precipitate then they get heavy and fall back in the reaction vessel. The precipitate is all the way up to the male piece of the 3 way adapter I think I am going to use a blow dryer to see if that helps it. Posting pics in 5 mins as requested

Hexavalent - 3-6-2012 at 14:10

It states on the HST website 'but is too flexible for vacuum application' . . .and this is what you are using it for.

What do you mean 'the precipitate'? Do you know what a precipitate is?

ScienceNoob - 3-6-2012 at 14:27

Sorry wrong word thus the name ScienceNoob umm hows about condensation or to use non science vocab I can see liquid speckles working up into the adapter. Yes that is what I'm using I didn't know any better I know learn to read is the answer I was just excited when I was ordering everything and made quite a few mistakes. However funny thing is I got this to work before using the same tubing just a different column was about the only thing different. I changed out the tubing real quick to new tubing which hasn't been used yet or exposed to any natural elements such as the sun. I have a question though I am using the infrared temp gun to see what the temp is up the column it is about 23 C outside the three way adapter is about 38.5C is this a good sign that it may be ready to come over soon?

Hexavalent - 3-6-2012 at 14:35

That is called the condensation front, and when it has tricked into the condenser it is called the fraction, which is the distillate.

No, the outside temperature of the 3-way adapter and the BP of the liquid at 170*C suggests that the liquid will reflux and drip back into the flask WAY before going anywhere near the condenser.

Is it feasible to do the distillation indoors where there is no wind? Add some fibreglass wool insulation between the layers of foil if possible and if necessary heat the outside gently with a heat gun or hairdryer. Turn off the magnetic stirrer for about 10 seconds... .when the vortex has disappeared, can you see bubbles forming and rising to the top? This will probably tell you if it's boiling or not. Be certain when measuring with the infrared gun to hit the temperature of the liquid, not the hotplate itself. Can you see any other signs of actual boiling? Can you see little drops of liquid entering the flask again from the bottom of the fractionating column?

Also, how fast is the water entering the aspirator? A low speed (low pressure) will produce a very weak vacuum . . .perhaps your mains water pressure was different on that day where it worked.

Is this, or something similar, what you have for supplying the vacuum?

[Edited on 3-6-2012 by Hexavalent]

ScienceNoob - 3-6-2012 at 14:37

here is the aspirator and tubing picture

Hexavalent - 3-6-2012 at 14:42

Can you post some pictures;

a) With the entire setup in view
b) With the flask in view, WITHOUT magnetic stirring being switched on
c) With the entire aspirator setup in view??

ScienceNoob - 3-6-2012 at 14:45

Yes I have seen it Reflux (I am pretty sure this is when the condensation? drips back down into the reaction vessel) quite a few times I have not tried to turn of the magnetic stirrer yet I will try that here in a few minuets. I can't do it inside no one trusts me really I don't trust myself yet either. I did pack it the inside with some steel wool I thought this would help with the heat problem. I also thank you for the clarification on vocabulary very foolish to use words that you are unsure of the definition of said word or words. I also see no little drops of liquid at the bottom of the column it is all trying to work its way up at the moment. The adapter is getting very foggy though but the thermometer just won't jump.

ScienceNoob - 3-6-2012 at 14:48

Quote: Originally posted by Hexavalent

That is called the condensation front, and when it has tricked into the condenser it is called the fraction, which is the distillate.

No, the outside temperature of the 3-way adapter and the BP of the liquid at 170*C suggests that the liquid will reflux and drip back into the flask WAY before going anywhere near the condenser.

Is it feasible to do the distillation indoors where there is no wind? Add some fibreglass wool insulation between the layers of foil if possible and if necessary heat the outside gently with a heat gun or hairdryer. Turn off the magnetic stirrer for about 10 seconds... .when the vortex has disappeared, can you see bubbles forming and rising to the top? This will probably tell you if it's boiling or not. Be certain when measuring with the infrared gun to hit the temperature of the liquid, not the hotplate itself. Can you see any other signs of actual boiling? Can you see little drops of liquid entering the flask again from the bottom of the fractionating column?

Also, how fast is the water entering the aspirator? A low speed (low pressure) will produce a very weak vacuum . . .perhaps your mains water pressure was different on that day where it worked.

Is this, or something similar, what you have for supplying the vacuum?

Nope what you see in the picture is the so called aspirator aka Pond Pump attached to an adapter which is attached to the water hose inlet which is attached to the condenser when I turn on the pump it fills really quick like within maybe 20 seconds? I will go back down now to get better pictures my lab top is not ideal for this lol
[Edited on 3-6-2012 by Hexavalent]

Hexavalent - 3-6-2012 at 14:48

May I ask, Mr Noob, how old you are?

I can also see from your earlier photos that your thermometer is over-immersed, which can give an inaccurate reading. The base should be parallel with the side arm;

[Edited on 3-6-2012 by Hexavalent]

ScienceNoob - 3-6-2012 at 14:52

I am 19... lack of maturity? I can tighten up if need be... :cool:

Hexavalent - 3-6-2012 at 14:57

No, just lack of confidence and effort mainly.

Look up the terms to make sure you use them correctly and avoid ambiguity . . .how long have you been doing chemistry BTW?? Why don't your family trust you? With some dedicated space to keep your stuff, a fire extinguisher, a regulated hotplate, safety gear and common sense most experiments can be done safely.

Again, try insulating the column even more and supply additional heating if necessary to it. Make SURE the liquid itself is actually boiling in the flask, and be sure that a vacuum is actually coming out of the aspirator . . .answer some of my questions and then I can help answer yours much better

I'm 14 BTW and my family trust me

ScienceNoob - 3-6-2012 at 15:14

I feel ashamed, so bad right now... I actually just started last week I am doing this as a hobby. I am majoring in Computer Science with strong emphasis on software application development. I would like to say I am impressed with your level of maturity for your age and your intellect in this area I have a feeling you will do great things one day. Also the place where I live is an apartment complex so I do not wish to endanger others with my stupidity god forbid something goes wrong. I am however pretty careful and paranoid about almost every move that I make while carrying out my procedure. Here are some of the pics as requested. Also I am not getting a temp of 51C at the adapter...

ScienceNoob - 3-6-2012 at 15:17

Oh to add I did as instructed it is boiling without stirring I tested it for 60 secs and I would like to correct the typo in the last post I am now getting a temp in the three way of 51 C I am about to try heating with a blow dryer for a while as instructed. I thank you for your help and I do plan on studying the terminology from now on before using it in a sentence xD

ScienceNoob - 3-6-2012 at 15:43

I shut it down for the day should not have taken this long.

Paddywhacker - 3-6-2012 at 23:13

Great work Hexavalent, you have a nice tutorial talent.

Noob, you do realise that the vacuum has to be applied to the opening marked '9' in Hexavalent's diagrams on page 1, don't you?

It is difficult to make out exactly what your setup is from your photographs. Maybe you could draw your setup, either in a paint program or on a sheet of paper and then scan or photograph that.

Once we are on the same wavelength about your setup then things will go more smoothly. A thought before I hand you back to Hex ... if you have already distilled off the low boiling fractions in an earlier experiment then your oil will boil at a higher temperature than you expect.

Hexavalent - 4-6-2012 at 02:46

Thanks, Paddywhacker!

ScienceNoob ~ are you using the same oil now as when it worked for you the first time? If so, then as Paddy stated, all of the lower boiling fractions (those with a lower molcular weight) will have come off in that first run, leaving you with higher boiling fractions (those with a higher molecular weight) this time around.

I can only second what he also says about the diagrams; the images you have posted so far are 'incomplete' and make it very hard to see precisely what's going on and what you are doing and how your apparatus is actually setup.

Additionally, are you sure that the aspirator can generate a sufficient vacuum for a long distillation? IME short filtrations are fine with them but long distillations are a no-no. For the lower boiling fractions, it is probable that a vacuum is not necessary to boil them under a reasonable temperature, but the longer-chain ones, thusly those with higher boiling points - probably do need it to lower their BP to make it a more easily attained temperature for your heating apparatus.

Supplu us with details, and we shall supply you with answers. I still don't believe, though, that fractional distillation under vacuum is a good place to start for a beginner, hence the ambiguity we get from the array of factors that could be causing your problem and you not using the proper terms correctly without even bothering to research them and their definition first.

I should point out, however, that with vacuum distillation you were corret to use a stir bar and not boiling stones to avoid bumping or superheating
(sudden, violent burts of boiling that can cause the original mixture to splash up into the stillhead, damage apparatus and cause injury) - under negative pressure, I recall reading somewhere that standard boiling chips do not work as, because of the pressure differences, they cannot release their little bubbles of air when heated that rise to the top and promote smooth boiling.

[Edited on 4-6-2012 by Hexavalent]

mr.crow - 5-6-2012 at 10:21

What are you distilling from camphor oil?

We are happy to help, but distilling safrole on your apartment balcony isn't the best way to get into it or represent amateur science