A model for autotrophic growth of Chlorella vulgaris under photolimitation and photoinhibition in cylindrical photobioreactor

• A growth model accounting for photolimitation and photoinhibition was developed.
• The model could predict the coupled autotrophic growth and light distribution.
• Model predicts experimental data reasonably well for cylindrical photobioreactor.
• The model accuracy depends on parameter determination for specific growth rate.

A model for the autotrophic growth of Chlorella vulgaris (C. vulgaris) under photolimitation and photoinhibition in cylindrical photobioreactor was developed by taking into account the interactions between the biomass concentration and light intensity. The growth kinetic model for a batch system was developed by coupling the light distribution under photolimitation and photoinhibition effects with the biomass growth with respect to incident light intensity on the surface of the reactor. The developed model could successfully simulate the specific growth rates, light intensity distribution in the reactor, average light intensities, and biomass concentrations at a given incident light intensity with good accuracy. The prediction of the cell density primarily depended on the determination of the parameters included in the specific growth rate expression, which is a function of the light intensity distribution. Despite the limitation of the semi-empirical specific growth rate expression, the coupled model could predict the biomass growth in different reactor sizes.