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Cephalo

Solvent vacuum evaporation

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Morning,

:)

Please forgive my English and unfamiliarity with some of the terms I need.

Outside my field...

 

We are trying our luck with crude oil extracts from plant material. Soak the dry plant material in a solvent (Ethanol/Acetone/ Ethylacetate Etc...)

We have been working in lab scale using a rotary evaporator.

Now I need to design and purchase a larger system for doing the same basic thing.

Evaporating a solvent and collecting the oil.

The goal is to evaporate 100L of solvent in about 8h of work.

So... here is what I think we need (and a few questions):

1) 5L double jacketed reactor (Vacuum prof).

2) A heater/ water calculator for the jacket (Heating capacity? Pump speed and type? How not to break the glass jacket?)

3) A condenser- I have been told that we need a very large joint 45/40 and a very large surface area of at least 0.8m2 - Not sure how much it its true.

4) A chiller circular for glycosomething- to cool the condenser (Cooling capacity? Pump specifications?)

Any advice would be very much appreciated!

 Thank you

  Cephalo

 

 

 

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Don't rush to get it all done in 8 hours. Be safe. Avoid fire sources around your distillation kit. Your set up seems sound for a standard distillation. If you don't really know what you are doing on a small scale then don't scale it up. Maybe people haven't responded because some people use this technique to extract oils from plants that they are not legally allowed to own. Therefore people are probably reluctant to comment.

Can I ask  -  what are you extracting and from which plant?

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22 hours ago, DrP said:

Don't rush to get it all done in 8 hours. Be safe. Avoid fire sources around your distillation kit. Your set up seems sound for a standard distillation. If you don't really know what you are doing on a small scale then don't scale it up. Maybe people haven't responded because some people use this technique to extract oils from plants that they are not legally allowed to own. Therefore people are probably reluctant to comment.

Can I ask  -  what are you extracting and from which plant?

Thank you kindly for your reply.

We are extracting specific carotenoids from plant leafs. Grow the plants, apply stress and collect the leafs.

It's under patents and I can't really say all I would like to.

Nothing illegal. It's for work...

I do not know how to calculate the parameters necessary for what you consider "a standard distillation".

At the end I need to order a reactor, a condenser, a heater and a chiller. What specs do I need?

The 8h is so we can finish one batch in one shift at work. Is it really too fast? 10L/h is too much to expect?

What do you think is more reasonable/ safe?

Thank you

  W

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3 minutes ago, Cephalo said:

At the end I need to order a reactor, a condenser, a heater and a chiller. What specs do I need?

I reckon a standard borosilicate 5L round bottomed flask would do. The condenser will also be fairly standard - get a larger condenser maybe if you are drawing the stuff off quickly - you 'can' stick 2 together but it will look a mess. Doubt it matters. You will probably have to play with your set up to perfect it. For a 5 L flask I would assume that the heater would be one of those electric heating mantles. I have seen them in use for 2L flasks. For smaller one offs we'd use an oil bath and heater, but for a permanent set up I think a dedicated heating mantle sized to fit your flask would suit. I am sure there are several ways to achieve the result you are looking for.

You might not need a chiller, the condenser might be enough - but otherwise you can submerge your collection vessel into a cold bath. A basin of IPA with a few handfuls of dry ice in it can work well for this. For a more permanent set I do not know what to use.

Have you considered drawing a vacuum? It will distil across a lot faster and at a lower temperature.  There are usually pressure/temperature charts in the back of chem catalogues or easy to find on the net that will show you what temperatures you will be aiming at for a given pressure compared to the boiling point of your liquid. 

Use clamps to secure your whole set up to some sort of frame on the bench. Clamp the condenser, clamp the flask, clamp everything to the frame (this will take the weight of each piece of kit off of the joints in the glass and just keep the whole thing more stable). You can get little clips also to help hold the glass joints together. Maybe grease the joints lightly with silicone grease. Even clamp the tubes that carry the water through the condenser to keep it all tidy. Use wire tightened around the fitting of the tube to the condenser to stop it coming off and causing a flood when you are not looking.  

Keep a fire extinguisher near...  but that is standard lab kit anyway. :) even those electric heating mantles can short out and cause a fire. I've put one out myself  - naked flames licking up around the flask and reflux condenser full of solvents at their boiling point. Scary.

Anyway - I'm not an expert - these are just my first thoughts based on doing distillations in the past - take or leave what I have said - feel free to ask any questions. GL.

 

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On 4/4/2018 at 4:27 PM, DrP said:

I reckon a standard borosilicate 5L round bottomed flask would do. The condenser will also be fairly standard - get a larger condenser maybe if you are drawing the stuff off quickly - you 'can' stick 2 together but it will look a mess. Doubt it matters. You will probably have to play with your set up to perfect it. For a 5 L flask I would assume that the heater would be one of those electric heating mantles. I have seen them in use for 2L flasks. For smaller one offs we'd use an oil bath and heater, but for a permanent set up I think a dedicated heating mantle sized to fit your flask would suit. I am sure there are several ways to achieve the result you are looking for.

You might not need a chiller, the condenser might be enough - but otherwise you can submerge your collection vessel into a cold bath. A basin of IPA with a few handfuls of dry ice in it can work well for this. For a more permanent set I do not know what to use.

Have you considered drawing a vacuum? It will distil across a lot faster and at a lower temperature.  There are usually pressure/temperature charts in the back of chem catalogues or easy to find on the net that will show you what temperatures you will be aiming at for a given pressure compared to the boiling point of your liquid. 

Use clamps to secure your whole set up to some sort of frame on the bench. Clamp the condenser, clamp the flask, clamp everything to the frame (this will take the weight of each piece of kit off of the joints in the glass and just keep the whole thing more stable). You can get little clips also to help hold the glass joints together. Maybe grease the joints lightly with silicone grease. Even clamp the tubes that carry the water through the condenser to keep it all tidy. Use wire tightened around the fitting of the tube to the condenser to stop it coming off and causing a flood when you are not looking.  

Keep a fire extinguisher near...  but that is standard lab kit anyway. :) even those electric heating mantles can short out and cause a fire. I've put one out myself  - naked flames licking up around the flask and reflux condenser full of solvents at their boiling point. Scary.

Anyway - I'm not an expert - these are just my first thoughts based on doing distillations in the past - take or leave what I have said - feel free to ask any questions. GL.

 

On 4/4/2018 at 4:27 PM, DrP said:

I thought of a water heater circulation for the reactor jacket. But I don't know how to calculate the heating capacity necessary. And a glycol chilling circulating for cooling the condenser. 
How do I calculate the heating and chilling capacity?

 

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Not sure you need to get tied up with heat capacities and calculations. Just get the temp right for your distillation at the pressure you are using and heat to just below that  -  then take it up slowly until it stabilizes at your chosen temp. Again - with the chiller  -  just chill and let it happen. :cool: Just run cold tap water through the condenser and chill your collection vessel maybe with the solvent/dry ice mix. Literally just have the collection vessel dipped into the dry ice/alcohol bath and clamp it there - the temperature gradient will also help pull the product down into the vessel.

 

 

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