Supercritical CO2 Extraction (Sofact): Green Technology at the Service of Perfume

The Different Extraction Processes and the Perfumer’s Organ

There are different extraction processes for raw materials in perfumery:

• Distillation
• Volatile solvent extraction
• Expression
• Enfleurage
• Head space
• CO2 or sofact extraction

There are, in total, 1,000 natural raw materials and 3,000 synthetic raw materials. The perfumer can therefore select those they wish to use, according to their tastes.

If they are independent, they will be very free in their choice of raw materials, and will generally select 1,000 (natural and synthetic). However, if they work for a large company, the perfumer will be limited to the latter’s perfume organ.

New raw materials are discovered and marketed every year, while others disappear, often due to legislation which is increasingly strict. Similarly, over time, raw material extraction techniques are perfected and become increasingly sophisticated.

Note that: not all perfumers have access to noble products resulting from the CO2 extraction technique, or sofact.

What is CO2 or Sofact Extraction?

CO2 extraction, also called “sofact”, is an extraction process carried out at high pressure, without excessive temperature load, and without coming into contact with oxygen.

The CO2 solvent, or carbon dioxide, is then in a supercritical state, that is to say in a form situated between the liquid and gaseous state, which is generated at a pressure greater than 73 bars. The temperature is quite low (31° C), which also allows preserving all the molecules of the treated raw material.

Technical Operation

Sofact technology is very innovative, but its process remains quite simple:

1. The raw material is placed in cylindrical baskets equipped with filters at both ends.
2. These baskets are then placed in the extractor, where CO2 circulates in liquid form.
3. The essential oil of the raw material will subsequently be dissolved in the CO2.
4. Then, the pressure is reduced, which allows the CO2 to recover its gaseous form.
5. The fragrant extract is then collected in the separator, while the CO2 gas continues its course and becomes liquid again, before being reused.

What is Supercritical CO2 Gas?

You should know that carbon dioxide or CO2 exists in 3 forms: solid, liquid, gaseous. The supercritical state of CO2 is actually a fourth state in which a fusion is provoked between the gaseous state and the liquid state, thanks to pressure and heat.

Other uses: This method is also used in the food industry to decaffeinate coffee, de-nicotinize tobacco, or to work hops for beer.

What Are the Advantages of CO2 Extraction?

This extraction technique offers many benefits regarding respect for the environment, the raw material, and the quality of the scent obtained.

The Raw Material Treated with Respect

Supercritical CO2 extraction or sofact is the most recent extraction process, and the one allowing a scent to be reproduced as closely as possible to the smell of the raw material. It is a clean and gentle modern technology, used by solvent, and allowing obtaining an absolute very close to the natural smell of the raw material.

The latter is very little heated, and leaves no product residue. This technique is particularly effective for all materials having low volatility, such as spices, for example.

The absolutes created have the particularity of possessing remarkable olfactory qualities. Indeed, the scented products obtained are very faithful to the scent of perfumery raw materials. However, they are also more expensive, because products treated by CO2 are considered luxurious.

An Ecological and Non-Polluting Technique

Furthermore, CO2 is a solvent recognized as non-dangerous, and non-flammable, unlike hexane (cf. Volatile solvent extraction). Its use is therefore much safer.

This gas is also recyclable, and non-polluting, therefore respectful of the environment (one could qualify it as a “green solvent”). This method is therefore very ecological, because it generates no greenhouse gases.

Given the growing interest in more natural and ecological products and due to strict environmental regulations, this innovative extraction technique is growing strongly.

Conclusion

Supercritical CO2 extraction treatment, or sofact, is a very ecological treatment, which allows rediscovering classic perfumery products.

To realize the effects of this method, here is an interesting experiment to carry out: smell, for example, a rose absolute or a pink peppercorn treated by classic volatile solvent (hexane or benzene), then compare this scent with these same raw materials, treated by CO2.

In this way, you will be able to notice to what extent this technique preserves the original smell of the raw material: it is a real delight! The only disadvantage is of course its cost, which is more expensive.