The Eucalyptus genus is native to Australia and comprises more than 600 species. These trees are used primarily for their wood and may also provide other products including the oil, which has a variety of industrial and pharmaceutical purposes. Most species of eucalyptus trees produce some essential oil, but only about 20 have commercially viable concentrations of oil in their leaves. Eucalyptus oil is extracted through an industrial process that uses a specific type of distillation.
Load about 8 tons of fresh, uncompressed eucalyptus leaves in a large vat with a series of steam pipes that run along its bottom. Secure the lid tightly to the vat with locking clamps.
Turn the boiler on and begin feeding steam through the pipes at the bottom of the vat. This will cause steam to pass through the leaves which will vaporize the essential oils in the leaves. This vaporization process requires 3 to 4 hours and will leave a black liquor which will drain through a hole in the bottom of the vat.
Collect the eucalyptus vapor through outlets at the top of the vat. The vapor will collect in a central pipe that is surrounded by pipes that contain cold water. The water circulates through this condenser and cools the vapor back to a liquid state.
Drain the condensed distillate into a collection vessel. The distillate contains a water and oil component which will eventually separate. The oil may then be skimmed of the surface. Pour the oil into drums for further refinement.
Rectify the unrefined eucalyptus oil. This is a more specific type of distillation which includes the use of chemical reagents which remove the impurities in the eucalyptus oil.