Figure 11

Possible extraction and transesterification mechanisms for ultrasonic and microwave induced reactors in series: a) microalgal cells in water are exposed to ultrasonication; b) ultrasonics align the algal cells along the vibrations; c) ultrasonics coagulate to form floc and concentrate the algal cells; d) concentrated algal cells exposed to microwaves in the solvent medium; e) microwaves induce diffusive and disruptive mechanisms and create hotspots to extract the oils and lipids; f) algal lipids extracted and transesterified by the microwaves.