Usage of Chlorella vulgaris biomass in microalgae-based bioethanol production

In this thesis study, bioethanol was produced from Chlorella vulgaris biomass with high sugar content. Candida boidinii yeast was used in fermentation experiments. In order to maximize the resulting reducing sugar and bioethanol concentrations, important parameters such as microalgae cultivation condition, pretreatment method, initial raw material concentration and different nitrogen sources and mineral salts were optimized. The highest reducing sugar concentration was determined as 16.23 g/L in the photoheterotrophic medium containing carrot pomace, and the highest bioethanol production was reached at 1% H2SO4 (v/v) and 200 g/L initial raw material concentration. It has also been found that nitrogen sources and mineral salts increase the production of bioethanol. The highest concentration of bioethanol obtained from the wet biomass of Chlorella vulgaris was found to be 4.54 g/L for Candida boidinii. In addition theoretical ethanol yield %54.69, the QP value is 0.38 g/L.h and YP/S are calculated as 0.38 g/g.