Essential oil distillation

thomas

Another thinking-out-loud post.

I have inherited a 500mL round bottom flask and heating mantle from my lab. I’m trying to see what I would need to make it into an essential oil still.

Option 1a: simple distillation, 250 mL capacity – 29/32

Option 1 is the cheapest

  • Round bottom flask 500 mL 29/32 €0
  • Elbow 75 degrees 29/32 €8.34
  • 14/32 stopper €0
  • Jacketed straight condenser 200 mm 29/32 €16.85
  • Receiving adapter 29/32 €8.60
  • Separatory funnel 250 mL €13.18

Total: €46.97

Option 1b: simple distillation, 250 mL capacity – 24/29

Same but 1 size down

  • Round bottom flask 500 mL 29/32 €0
  • Elbow 75 degrees 29/32m to 24/29m €8.14
  • 14/32 stopper €0
  • Jacketed straight condenser 200 mm 24/29 €6.86
  • Receiving adapter 24/29 €8.87
  • Separatory funnel 250 mL €13.18

Total: €37.05

Option 1c: simple distillation, 250 mL capacity – 19/26

Same but 2 sizes down again, needs adapter

  • Round bottom flask 500 mL 29/32 €0
  • Adapter 29/32m – 19/26f €6.80
  • Elbow 75 degrees 29/32 €6.45
  • 14/32 stopper €0
  • Jacketed straight condenser 200 mm 19/26 €12.67
  • Receiving adapter 19/26 €8.60
  • Separatory funnel 250 mL €13.18

Total: €47.40

Option 2a: reflux distillation, 250 mL capacity – 29/32

This one is the most simple option; a reflux separator with a condenser, straight onto the flask.

  • Round bottom flask 500 mL 29/32 €0
  • Reflux separator 29/32 €28.99
  • Jacketed Dimroth condenser 300 mm E.L. 29/32 €30.36

Total:

Option 2b: reflux distillation, 250 mL capacity – 24/29

Same as before but reduced to 24/29, i.e. thinner separator & column

Total: €56.60 (200 mm) / €65.67 (300 mm) / €67.76 (400 mm)

Option 2c: reflux distillation, 250 mL capacity – 19/26

Same as before but reduced to 19/26, i.e. thinner separator & column

  • Round bottom flask 500 mL 29/32 €0
  • Adapter 29/32m – 19/26f €6.70
  • Reflux separator 19/26 €29.61
  • Jacketed Dimroth condenser 300 mm 19/26 €30.42

Total: €66.73

Option 3a: reflux steam distillation, 500-2000 mL capacity – 24/29

This one is the maximum I can do with my 500 mL heating mantle, although I could possibly fit a 2L chromatography flask too. Reduced to 24/29 better to keep 29/32 for easier filling/emptying? Reduce reflux separator and Dimroth condenser?

  • Round bottom flask 500 mL 24/29 €12.86
  • Some sort of reservoir
    • 500 mL round 24/29 €19.63
    • 1000 mL round 24/29 €27.78
    • 2000 mL round 24/29 €41.14
    • 500 mL globe separator €18.11
    • 1000 mL globe separator €26.66
    • 500 mL globe separator 29/32 €21.51
    • 500 mL straight column separator 24/29 €25.61
    • 500 mL straight column separator 29/32 €29.40
    • ~500 mL straight column 24/? (50×300 mm) €32.59
    • ~1000 mL straight column 24/? (70×300 mm) €41.00
    • Wait a minute, I have an awesome big ~1.8L glass reservoir that is the perfect shape! It’s just missing the DN100? lid. The lid on its own is more expensive than all the other options though. Maybe use a temperature resistant funnel? Print a PETG lid and line it with PTFE baking sheet?
  • Reflux separator 24/29 €27.92 €32.90
  • Jacketed Dimroth condenser 300 mm 24/29 €29.43

Total:

Option 3b: as above, but I’ve put more thought into it

Putting a stopcock between the boiling flask and the reservoir is a bad idea. It’ll clog up with plant material. Also, I want the biggest diameter reservoir opening possible, to make it easier to fill/empty/clean.

  • Round bottom flask 500 mL 29/32 €0
  • Reservoir
  • 29/32 option (€68.05)
    • Clevenger apparatus 5mL 29/32 €37.76 don’t trust
    • Jacketed Dimroth condenser 300 mm E.L. 29/32 €30.29
  • 24/29 option (€69.60)
    • Adapter M29/32 F24/29 €7.33
    • Clevenger apparatus 5mL 24/29 €32.90
    • Jacketed Dimroth condenser 300 mm E.L. 24/29 €29.37
  • 24/29 option with thermometer adapter (€80.86)
    • Y adapter M29/32 2*F24/29 €14.80
    • Thermometer adapter 24/40 €3.79 (probably fits)
    • Clevenger apparatus 5mL 24/29 €32.90
    • Jacketed Dimroth condenser 300 mm E.L. 24/29 €29.37

Things to figure out

  • Can a Clevenger device even be used with steam distillation (refluxing through the biomass flask)?
    • Yes, e.g. 1 2 3
  • How on earth am I going to clamp such a tall installation
  • Do I want to use my jacketed column? Perhaps upside down, but how would I connect the little screw adapter into the 24/29 Clevenger? Maybe just get the cheaper shorter 200 mm Dimroth for €21.27?
  • Could I perhaps use my condenser as part of a DIY Clevenger? It has an extra port at the bottom. Would need to improvise a stopcock at the spout. This would make for a much less tall setup; it would sit next to the boiling flask / biomass vessel stack, with hydrosol overflow going up diagonally back into the boiling flask or biomass flask. Would need some sort of splitter adapter there, a hydrosol hose, a lid for my reactor (biomass) vessel, possibly an insulated metal pipe from the vessel to the condenser.. Maybe if I want a big volume, I should just hook up the Clevenger & Dimroth to a pressure cooker or other metal pot.
  • Do I need to put some sort of restriction at the top of the Dimroth condenser to limit flow/vapor loss?
  • Would a Vigreux column do something? I’m already refluxing

Option 3c

Ok I’ve decided I want the 5mL graduated 24/29 Clevenger and a Dimroth on top of it, but I think I can get away with a shorter 200mm one because of the low heating power and high efficiency of the condenser. I can ramp up the coolant pump if needed, or just add another condenser on top if it turns out to be too short.

Total: €109.80 (dual with stopper) or €107.37 (single, no stopper)

Option 3d

What would a 2L biomass flask cost?

Total: €126.56

Option 3e

What about the one with a bigger mouth?

  • Round bottom flask 500 mL 24/29 €12.84
  • Biomass flask: 2000 mL round 50/40 & 24/40 €49.24
  • Adapter M50/40 F24/29 €14.45
  • Clevenger apparatus 5 mL 24/29 €32.90
  • Dimroth condenser 200 mm 24/29 €21.27

Total: €130.70

Things to figure out

  • Will my 200W heater provide enough heat for a 2 L biomass flask?
    • 500 g plant material: 1 kW for 4.5 h, 6 kg of water -> 200W can do 100 g?
    • ~1 kWh/kg -> at 4.5 h, 200 W can do ~1 kg?
    • ~1.9 kWh/kg -> at 4.5 h, 200 W can do ~500 g?
    • 0.3-4.0 kWh/kg, best results at 1.2-4.0 kWh/kg -> at 4.5 h, 200 W can do ~250-750 g?
    • 250 g per liter biomass
    • Ergo, 200W might just keep up with 500 g / 2 L flask? Otherwise, just run for longer?
  • Will my 500 mL boiling flask provide enough water for the process?
    • Fill to max 50%
    • Water is refluxed
    • 2.8 L/kg -> water must be refluxed at least 6 times
    • If not enough, just add through condenser? And pre-wet biomass?
  • Do I want to spend the extra €20 on a flask twice the size?
  • Do I want to spend €100+ on new glassware when I already have used stuff? It might be toxic and I’d have to figure out connections, especially both sides of the 1.8L reactor that has no lid.. The condenser I could probably figure out now that I know the screw connections. I still want a Clevenger in any case.
  • Microwave assisted extraction or microwave pretreatment

What I have bought

I’ve bought a Clevenger (5mL graduated, 24/29 connections).

I’ll try to connect everything I already have up first. But none of those things are made to connect. There are 4 places that I’d like to be mostly “steam tight”:

  • 500 mL round bottom flask to biomass flask: 29/32 ground glass to glass hose connection. Maybe drill out a rubber stopper?
  • Biomass flask to biomass flask lid: custom clamp? Or maybe make a new lid from stainless steel or old pot lid?
  • Biomass flask lid to Clevenger: GL25 (or was it GL32?) screw connection to 24/29 ground glass – maybe a 24/29 to hose adapter, and then stick it in a screw cap with teflon ring?
  • Clevenger to condenser: put the glass hose connection of the condenser into a drilled out 24/29 rubber stopper again?

To be continued.

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