Pressure makes perfect: ECU innovator refines essential oil production

A researcher from Edith Cowan University (ECU) has pioneered an innovative essential oil extraction process that could cut costs and increase yields.

Essential oils are used in a range of industries, including food, cosmetics, fragrance, and pharmaceuticals. However, traditional extraction methods are limited by low yields, long processing times and thermal degradation of sensitive bioactive compounds.

ECU PhD student Muhammad Hassnain noted that the Instantaneous Controlled Pressure Drop (CID) technology is an advanced intensification method to overcome these challenges by applying compression-decompression cycles and modifying plant structure to enhance heat and mass transfer.

“Traditional extraction methods involve lengthy extraction periods, consume significant amounts of energy, incur higher expenses, yield low outputs, and have more substantial environmental impacts,” Mr Hassnain said.

“The CID technology can couple thermo-mechanical effects to produce high-quality essential oils with low energy consumption. This method also significantly cuts down on the time it takes to produce essential oils, while simultaneously increasing the yield.”

A review conducted by Mr Hassnain and his co-authors has highlighted the three existing CID variants currently available to market, in which the material is generally treated with highly saturated steam for a brief period, followed by a sudden drop in pressure to create a vacuum, resulting in the rapid vaporisation of volatile compounds. The process occurs in cycles, whereby at the end of each cycle, a condensed emulsion of water and volatile liquids is formed in a vacuum tank.

This emulsion is then rapidly cooled due to abrupt volume expansion, thereby preventing thermal degradation.

“The real advantage of CID lies in its efficiency; it delivers faster extraction with lower energy use and minimal solvents, all while improving overall yield. The process also avoids some of the paradoxical effects we see in traditional extraction methods, which means we achieve much better extraction efficiency overall,” Mr Hassnain said.

Mr Hassnain, under the supervision of Dr Muhammad Rizwan Azhar and with industry collaboration, is now optimising the CID technology for the extraction of Indian and Australian sandalwood oil.