Using Steam Distillation to Produce Essential Oils

Andrew Collins

The Renaissance physician Paracelsus (1493-1541) did not invent steam distillation, but rather the modern term used for the volatile oils of plants—essential oils, directly recalls his alchemical theory of quinta essentia (literally fifth element).

For Paracelsus the process of distillation involved harnessing the innate powers of fire and flame to separate and purify the essential characteristics from crude matter. Today the theory behind this common laboratory procedure is far less romantic or poetic, involving directly quantifiable differences in vapor pressure and Raoult's Law.

Theories aside, Paracelsus was an expert distiller and the alembics and retorts (see examples on title page) he used to produce essential oils are similar to the laboratory equipment used around the world today. Therefore these instructions will make use of modern laboratory equipment.

Introduction

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1

Required Glassware

2

Stopper Clainsen Adapter Still Head Distillation Adapter

Addition Funnel Condenser Separation Funnel

Round-Bottom Flask

Biomass Flask

x3

Additional Required Equipment

3

Hot Plate Water Pump

TubingWater Tub

4

Apparatus Assembly

Hot Plate

Round-BottomFlask

ClainsenAdapter

AdditionFunnel

Condenser

DistillationAdapter

Still Head

Stopper

SeparationFunnel

WaterPumpWater

Tub

Biomass Flask

Tubing

Water

Steam distillation requires boiling water to produce steam.

Ice

To operate effectively the condenser requires cold water.

Biomass

Choose plant material which is suitable for steam distillation. The following represents a mere fragment of all possibilities: caraway, cinnamon, clove, cumin, rosemary, peppermint, spearmint, and lavender.

Necessary Materials

5

!To prevent personal injury avoid steam discharges from the apparatus and avoid operating around children or pets.

?Persian physician Avicenna (c. 980 - 1037) invented steam distillation in the eleventh century.

6

Apparatus Preparation

Biomass

H2O

H2O

H2O

1. Check for loose connections between glassware.

2. Add water to Round-Bottom Flask, Addition Funnel, and Water Tub.

3. Load biomass into Biomass Flask.

4. Make sure Water Pump is operating and condenser water is flowing.

5. Add ice to Water Tub.

7

Apparatus Operation

Biomass

H2O

H2O

EO

H2O

1. Turn on Hot Plate.

2. Confirm steam is being generated.

3. Check for steam leaking out of glassware.

4. Verify Water Pump is operating and condenser water is flowing.

5. Add ice to Water Tub as necessary.

6. Transfer water from Addition Funnel to Round-Bottom Flask as necessary.

7. Watch essential oil begin to collect!

8

Collecting Essential Oil

Essential OilLighter Than

Water

Water

Essential OilHeavier Than

Water

1. After 2-4 hours the steam distillation will be finished.

2. Turn the Hot Plate off and let the apparatus cool down. Remove the Separation Funnel.

3. If essential oil which is heavier than water is in the bottom of the separation funnel collect it by carefully turning the stopcock and quickly closing the stopcock.

4. Drain away water collected in the Separation Funnel.

5. If essential oil which is lighter than water is in the top of the separation funnel collect it.

!It is important to open and close the stopcock quickly and firmly, otherwise essential oil may be lost.

?Annual global production of spearmint oil is 1400 metric tons, 70% comes from the United States.

Bibliography

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Adams, Roger, John R. Johnson, and Charles F. Wilcox. Laboratory Experiments in Organic Chemistry. New York: Macmillan, 1979. Print.

The Alchemy Web Site. Web. 10 May 2010. <http://www.alchemywebsite.com/>.

"Essential Oil." Wikipedia, the Free Encyclopedia. Web. 10 May 2010. <http://en.wikipedia.org/wiki/Essential_oil>.

Fessenden, Ralph J., Joan S. Fessenden, and Patty Feist. Organic Laboratory Techniques. Pacific Grove, CA: Brooks/Cole Thomson Learning, 2001. Print.

Harwood, Laurence M., Christopher J. Moody, and Jonathan M. Percy. Experimental Organic Chemistry: Standard and Microscale. Oxford: Blackwell Science, 2008. Print.

Pavia, Donald L. Introduction to Organic Laboratory Techniques: a Small Scale Approach. Belmont, CA: Thomson Brooks/Cole, 2005. Print.

"Steam Distillation." Wikipedia, the Free Encyclopedia. Web. 10 May 2010. <http://en.wikipedia.org/wiki/Steam_distillation>.

Teuscher, Eberhard, Ulrike Bauermann, and Monika Werner. Medicinal Spices: a Handbook of Culinary Herbs, Spices, Spice Mixtures, and Their Essential Oils. Stuttgart: Medpharm, 2006. Print.