Supercritical fluid extraction from vegetable materials

In the 21st century, the mission of chemical engineering is to promote innovative technologies that reduce or eliminate the use or generation of hazardous materials in the design and manufacture of chemical products. The sustainable use of renewable resources, complying with consumer health and environmental requirements, motivates the design, optimisation, and application of green benign processes. Supercritical fluid extraction is a typical example of a novel technology for the ecologically compatible production of natural substances of high industrial potential from renewable resources such as vegetable matrices that finds extended industrial application. The present review is devoted to the stage of development of supercritical fluid extraction from vegetable material in the last 20 years. Without the ambition to be exhaustive, it offers an extended, in comparison with previous reviews, enumeration of extracted plant materials, discusses the mathematical modelling of the process, and advocates a choice for the appropriate model that is based on characteristic times of individual extraction steps. Finally, the attention is focussed on the elements of a thermodynamic modelling framework designed to predict and model robustly and efficiently the complex phase equilibria of the systems solute + supercritical fluid.