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Essential oils

What is Essential Oil?

Essential oil refers to the general term for volatile aroma-containing substances obtained by processing and extracting from spice plants or aroma secreting animals. Generally, essential oils are volatile aromatic substances extracted from plant flowers, leaves, roots, seeds, fruits, bark, resin, wood core and other parts through steam distillation, cold pressing, liposuction or solvent extraction. Essential oils are divided into diluted (compound essential oils) and undiluted (single essential oils), such as cactus seed oil. Essential oils are very volatile and will evaporate quickly once they come into contact with air, so essential oils must be stored in dark and sealable bottles.

But one thing is that not all plants can produce essential oils. Only plants that contain balsam glands can produce essential oils. Essential oils are composed of some very small molecules. These highly volatile substances can be absorbed into the body by the nasal mucosal tissues, and send information directly to the brain, through the limbic system of the brain, to regulate emotions and the physiological functions of the body.

What Is the Best Extraction Method for Essential Oils?

If you want to know what essential oil extraction method is best for you, you need to understand what essential oil extraction methods are.

Steam Distillation

This is the most commonly used method for extracting essential oils from aromatic plants. 95% of essential oils from aromatic plants are extracted by distillation.

This method is to put the plant parts (flowers, leaves, wood chips, resin, root bark, etc.) containing aromatic substances into a large container (distiller), heating and burning or pass steam into the bottom of the container. When the hot steam is filled in the container, the aroma of essential oil components in the plant will evaporate with the water vapor, and as the water vapor passes through the upper condenser tube, it is finally introduced into the condenser.

The condenser is a spiral tube surrounded by cold water so that the steam is cooled and converted into an oil-water mixture and then flows into the oil-water separator. The oil that is lighter than water will float on the surface, and oil that is heavier than water will sink to the bottom of the water, and the remaining water is pure dew. Then use a separatory funnel to further separate the essential oils and hydrosols.

Steam Distillation

Steam Distillation


The quality of essential oils will be great by using this method to extract essential oils, but it is now less used because it is quite time-consuming.

Immerse the plant in a glass bottle filled with vegetable oil and expose it to the sun for several weeks, so that the flavor of the essential oil is absorbed by the fat. After the taste of the plants is filtered out, more herbal extracts should be added. Another way is to spread a layer of flowers on the thin lard. The flowers must be covered every day until the required concentration is reached,

and then add alcohol. When the alcohol evaporates, the essential oils are separated.

Solvent Extraction

Solvent extraction is mostly used for the extraction of delicate and fragile plant petals or resins that do not like heat sources.

Essential oils generally labeled as “absolute” on the market are immersed in a volatile solvent such as petroleum ether or ethane to transfer the aroma components. After the solvent evaporates, it will leave the vegetable wax block concrete, and then put it in the alcohol solvent. After dissolving, after the solvent evaporates, it will be refined into essential oil.

Squeeze Extraction

Most logarithmic citrus essential oils, such as orange, bergamot, grapefruit, and orange, are extracted by this method. Because most citrus essential oils cannot resist the heat of distillation, their essential components will be destroyed during the extraction process.

Supercritical CO2 Extraction

The principle of this method is that carbon dioxide in the supercritical state has special solubility for plant essential oils, and its solubility is related to density. The density can be adjusted by temperature and pressure to precipitate the essential oils.

According to different products and processes, essential oil extraction can be roughly divided into the above types. Therefore, to choose what method to extract essential oils, I believe you already have a general idea in your mind. With the development of science and technology, the technology of essential oil extraction is not limited to manual operation. The production of modern machines also makes the extraction process more convenient and can ensure the purity of the extraction.

What Machines Are Used to Extract Oil?

The essential oil extraction machinery currently provided by SED has a complete production line as well as machines which can be used independently. According to the different working principles of the machine, there are the following:

Extraction and Concentration Equipment Line

This Oil Extraction Equipment Line is suitable for the extraction of herbal materials, such as rose oil, zedoary turmeric oil, star anise oil, litsea cubeba oil, patchouli oil, peppermint oil, and lavender oil.

The working principle of this line is to use a steam distillation tank to extract water (wet steam), which is heated by a jacket and a steam generator.

Extraction and Concentration Equipment Line
Extraction and Concentration Equipment Line

Multi-functional Essential Oil Extraction and Concentration Equipment

This equipment line is used to extract the most basic equipment and can be used for various materials in the pharmaceutical, food, chemical and other industries. Different extraction processes such as water extraction, solvent extraction, and heat reflux can be used to extract various materials such as herbs, flowers, seeds, and fruits.

Food Edible Oil Extraction Machine

The oil extraction machine of this series is especially for making edible oil. The hydraulic principle is used to produce edible oil that meets the edible grade. In addition, when using this oil press, the entire oil output process is clear at a glance, which only takes about 5-7 minutes. The sesame oil press is small in size, occupies a small space, and has a fast oil extraction speed, which is very suitable for farms or small oil plants.

Industrial Herbal Ethanol Extraction Machine

The herbal ethanol extraction machine has multiple functions such as heat recovery, distillation, condensation, normal distillation, condensation, precipitation, and exudation.

At the same time, it has a variety of working pressure conditions to choose from: negative pressure, normal pressure, and positive pressure. It is suitable for distilled water, ethanol and solvents, which also meets GMP standards.

Ball Type Vacuum Concentrator & Single/Double Effect Vacuum Concentrator

The working principle of vacuum concentration is that under the induction of the secondary steam and the suction of the high vacuum of the separator, the concentrated material and the secondary steam enter the separator along the tangential direction at a relatively fast speed.

Ball Type

The ball-type vacuum concentrator is evaporation equipment that is mainly composed of a concentrating tank, condenser, and storage tank for recycled liquid.

Single/Double Effect Type

The structure and working principle of the double-effect concentration equipment are similar to that of the single-effect membrane concentration equipment, mainly including a heat pump, a second-effect heater and a second-effect separator.

The two concentrators above are suitable for fluid materials such as herbal medicine, glucose, starch, and dairy products, especially heat-sensitive fluids.

Where to Buy Oil Extraction Machine?

After reading this article, do you have a certain understanding of essential oil extraction? As a leading Chinese manufacturer of oil extraction equipment, SED Pharma is always committed to providing our clients with stable quality and thoughtful pre-sales & after-sales service. If you have a need for an essential oil concentrator or want more details, welcome to consult!


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