Microwave assisted process intensification techniques have been used in our research group since 2006, to improve extraction of valuable compounds from natural products. Microwaves have proved to be successful when pretreating such a different products like aromatic plants (to extract essential oils), microalgae (for pigments and triglycerides), wastewater sludge (to improve hydrolysis) or grape marc (for extracting polyphenols).
Microwaves allow fast volumetric heating, reducing time exposition to high temperature. The effect of microwaves, by itself or in combination with a solvent, cause damage in the cell wall, reducing mass transfer for components extraction. In some cases, like essential oil extraction from lavender or rosemary, the oil containing trichomes of the plant are exploded by microwaves, causing direct release of essential oil.
At the research group, the industrial use of microwaves is under study. The high cost of electricity demands high efficiency continuous processes, able to take the advantages from this promising technique while keeping economic and sustainability criteria.