Extraction of essential oils

An essential oil is a concentrated, hydrophobic liquid containing volatile organic compounds from botanical matter (plants, herbs, spices etc). Common techiques for extraction of essential oils are steam stripping and distillation. Essential oils are used in many flavour and fragrance applications including perfumery, aromatherapy and for food and beverage flavouring.

Most essential oil production uses traditional, crude and inefficient batch distillation techniques. Such systems typically expose the raw material to long periods (perhaps hours) of high heat, resulting in the thermal degeneration of the volatile oil constituents.

Alternatively, the Spinning Cone Column may be used for steam stripping of essential oils from a variety of raw materials and offers the following benefits over traditional techniques:

Short residence time
The residence time in the Spinning Cone Column is of the order of 10 to 15 seconds ensuring that thermally sensitive compounds are not damaged. Evidence of this can be seen in the examples to the right.

High efficiency
The high mass transfer efficiency of the Spinning Cone Column maximises the yield of essential oil recovered.

Variable operating temperature
The Spinning Cone Column can operate at or below 100°C, thus ensuring minimum thermal damage to heat sensitive volatile compounds.

The quality of oil recovered using the SCC is superior to that of traditional distillation. Some examples include:

• Garlic and onion - to produce lightly coloured oils without "cooked" notes.
• Mustard - for production of premium quality Allyl Isothiocyanate.
• Ginger - for the collection of both aqueous flavour and essential oils

Mint Oil Example

Garlic Oil Example