Cultivation of microalgae Chlorella vulgaris in photobioreactor for biodiesel production

Microalgae are gaining considerable attention as a feedstock for biodiesel production. They can be grown away from the croplands and hence do not compromise food crop supplies. The ability of microalgae to capture solar energy and fix CO2 is a promising process for sustainable production of biomass. Chlorella vulgaris may be suitable for biodiesel production due to its faster growth and easier cultivation compared to other strains. The effect of media composition and process conditions on biomass productivity of C. vulgaris are investigated in a laboratory scale photobioreactor. The results show excellent growth of C. vulgaris on 2X Tris-Acetate-Phosphate culture medium, reaching biomass concentrations around 7.7 g/L. The combination of process parameters that result in highest biomass for our system are: agitation at 600 rpm, temperature of 29°C, average light irradiance of 900 muE/ (m2 s), and 4% CO2 in air. The statistical analysis of biomass from fractional factorial experiments confirms that C. vulgaris growth in presence of the aforementioned process parameters can give highest biomass for our system from the process parameters that were studied. However, statistical analysis also reveals that increase in irradiance from 450 muE/ (m 2 s) to 900 muE/ (m2 s) in our system did not have significant effect on biomass concentration.