Due to the increasing rates of people’s application of essential oil in relaxing pressure and skin recuperation, to meet the growing market needs, essential oil suppliers try various ways to pursuit easy, cost effective and delicate quality essential oil extraction way. No matter how people strive for excellence on extraction essential oil, the way of extract essential oil will not going away from the following basic methods.
1.Distillation
Generally speaking, distillation way includes Steam Distillation and Water Distillation. It is the most common way for us to distillate essential oil, 95% of essential oil is distillated by this way.
By steam distillation, the plant raw material is placed on the basket sieve of the distillation barrel, while the high pressure steam goes through, the essential oil from the plant is released, and it evapotranspires to the steam. When this mixed gaseous fluid enters into the cooling system, the steam condensates to liquid state, due to different density, the essential oil separates from hydrolat by oil-water separator.
Due to the low pressure and temperature, this distillation way is suitable for heat sensible essential oil like neroli and rose.
2.Cold pressure
Cold pressure adopts manual or mechanical way to press pericarp, and then extract the essential oil. Most of citrus essential oil, like orange, bergamot, grapefruit, and lemon are extracted by this way. Due to most of citrus essential oil cannot resist the heat of steam, and the essence components are easily destroyed by distillation, currently, people adopts mechanical cold pressure way to exact essential oil from pericarps.
3.Enfleurage
Enfleurage is an ancient essential oil extraction way, it is called Enfleurage Absolute. Apart from Grasse in France, it nearly vanished in the common commercial market.
Science ancient, Enfleurage is the essential oil extraction way. Generally speaking, people usually extract essential oil from petal plants by this way. We place a sheet of glass on a wood plate, paint animal oil, and spread pedals, by this layer by layer way, extract essential oil by animal oil. It is noted that, in the process of extraction, we should frequently change petal or replace animal oil or glass sheet by cotton cloth covered with olive oil or jojoba oil.
4.Solvent extraction
Some delicate flowers or plant resins are not suitable for distillation essential oil, people use volatile solvent to extract their aromatic molecules, this extraction way is called Solvent Extraction. It mixes the volatile solvent and the plants to be extracted, by solvent to extract the essential oil. Usually, expensive floral essential oil is extracted by solvent extraction way.
5.CO2 extraction
CO2 Extraction began in 1980, due to the complicated structure and expensive costs, the extracted essential oil is marked as “CO2 extraction”. For its principle of compress CO2 into half liquid and half gas state, extract the aromatic molecules from plant. By exchange the pressure, makes gas volatilize, the rest parts are essential oil. By CO2 extraction, we get very fine quality essential oil, compared with traditional distillation, the aroma is perfect. By this extraction way, the essential oil is more close to the natural plant aroma. Without high temperature during distillation, and no residues rests, but very high costs, it is not very commonly used.