Essential Oil Distillation Apparatus Clevenger Type

This Clevenger-type essential oil distillation apparatus is the standard lab glassware for extracting essential oils from plant material by steam distillation and measuring how much oil you get. It continuously returns the water (hydrosol) to the boiling flask while collecting the pure oil in a graduated tube for direct measurement.

Components

A complete setup includes these core parts, made from borosilicate 3.3 glass to resist thermal shock:

• Boiling flask: A round-bottom flask (500ml or 1000ml, select from the drop-down) where the plant material and water are heated.
• Clevenger receiver (trap): A graduated tube that collects the condensed oil and water, with a side arm that returns the water to the flask.
• Condenser: Typically a Liebig or Allihn type (300mm is standard) above the receiver that cools the vapour back to liquid.
• Joints: Standard 24/29 or 24/40 ground glass joints for leak-proof connections.

Two Types, by Oil Density

Essential oils behave differently in water, so the apparatus depends on the oil's density:

• For oils lighter than water: The most common version (for example lavender, citrus or peppermint). The oil floats on the water in the graduated tube, and the extra water flows back to the flask through a return arm.
• For oils heavier than water: For oils like clove or cinnamon. The denser oil sinks to the bottom of the graduated receiver, and the water returns to the flask from a higher point.

How the Process Works

1. Heating: The plant material is boiled in water in the flask.
2. Vaporisation: Steam carries the volatile oils up into the condenser.
3. Condensation: The vapour cools and drips into the graduated receiver.
4. Separation: The oil and water separate into two layers because of their different densities.
5. Recycling: The water siphons back into the flask automatically, so the distillation can run for several hours to get the most oil.