An overview of mathematical modeling for conventional and intensified processes for extracting essential oils

Essential oils are extracted from plants by different methods, including traditional and emerging technologies. The so-called emerging technologies, such as extraction aided by microwaves and/or ultrasound, can improve heat and mass transfer, reducing processing times, energy requirements, and environmental impacts. Understanding the role of mass transfer and heating mechanisms in the performance of these intensified processes is critical for their efficient design. So far, several mathematical models have been developed to describe the effect of the different process variables involved in those extraction processes. This review aims to discuss the different models developed to describe the extraction behavior for both traditional and emerging technologies, identifying the theoretical basis, associated variables, and undertaken assumptions, intending to provide the readers with a helpful overview of the existing mathematical approaches and their feasibility for different applications.