Pervaporation in the separation of essential oil components: A review

Essential oils and their components have wide use in many areas of industry (chemicals, cosmetics, food, and pharmaceuticals), beyond presenting potential to be used to combat agricultural pests and as a component of active packaging, where raw essential oil may be used, or it can undergo a fractioning process to obtain fractions with different compositions with specific properties. However, the process of purification of essential oil components by fractional distillation is economically and energetically costly, despite the value and the potential of essential oil components for specific applications. The present review highlights the recent developments and use of pervaporation as an emerging process separation for the separation of essential oil components and terpenes in general. The review also addresses the polymers used to manufacture the pervaporation membranes. Additionally, it is presented a brief discussion about the challenges of using the pervaporation in large scale compared to vacuum fractional distillation, which is the standard separation procedure in the industry, and other fractioning methods. Despite the huge developments in the field of pervaporation and membrane manufacturing, there is not a suitable membrane capable to separate pure raw essential oil in specific components, neither into classes of components. However, the pervaporation is already being used in the obtainment of aroma compounds for specific uses, especially in food industry in the fields of dealcoholization of beverages, and in the recovery of aroma compounds from juice extraction and processing.