The microalga Nannochloropsis sp. was used in this study, in a biorefinery context, as biomass feedstock for the production of fatty acids for biodiesel, biohydrogen and high added-value compounds. The microalgal biomass, which has a high lipid and pigment content (mainly carotenoids), was submitted to supercritical CO 2 extraction. The temperature, pressure and solvent flow-rate were evaluated to check their effect on the extraction yield. The best operational conditions to extract 33g lipids /100g drybiomass were found to be at 40°C, 300bar and a CO 2 flow-rate of 0.62g/min. The effect of adding a co-solvent (ethanol) was also studied. When supercritical CO 2 doped with 20% (w/w) ethanol was used, it was possible to extract 45g lipids /100g drybiomass of lipids and recover 70% of the pigments. Furthermore, the remaining biomass after extraction was effectively used as feedstock to produce biohydrogen through dark fermentation by Enterobacter aerogenes resulting in a hydrogen production yield of 60.6mL/g drybiomass . © 2012 Elsevier Ltd.
Nobre, B. P., Villalobos, F., Barragán, B. E., Oliveira, A. C., Batista, A. P., Marques, P. A. S. S., Mendes, R. L., Sovová, H., Palavra, A. F., & Gouveia, L. (2013). A biorefinery from Nannochloropsis sp. microalga - Extraction of oils and pigments. Production of biohydrogen from the leftover biomass. Bioresource Technology, 128-136. https://doi.org/10.1016/j.biortech.2012.11.084