Oil extraction from enriched Spirulina platensis microalgae using supercritical carbon dioxide

Abstract

This article deals with the extraction of neutral lipids and antioxidants from enriched Spirulina platensis microalgae using supercritical carbon dioxide (CO2), and more particularly with the influence of experimental conditions on extraction yields and kinetics at laboratory and pilot scales. Preliminary studies were carried out at laboratory scale before the establishment of an experimental design: extraction curves were plotted for different autoclave fill rates, and under different conditions of pressure and temperature. Using a Response Surface Methodology, the significant influence of pressure on extraction efficiency was highlighted. Surface responses showed that, in the studied experimental field, mass loss increased when pressure, temperature, and CO2/microalgae mass ratio increased. Extract analyses showed that oil extracts contained chlorophylls a and b, as well as β-carotene. Finally, larger-scale experiments were carried out with batches of 1 and 50kg (scale-factors of 100 and 5000, respectively) and the results were consistent with those obtained at laboratory scale.