Productivity of outdoor algal cultures in enclosed tubular photobioreactor

Abstract

At quasi-steady-state outdoor cyclic fed batch cultures of Chlorella pyrenoidosa, the growth irradiance incidented on the tubular photobioreactor increased about five-fold between 9:00 a.m. and noon. Overheating of the cultures was observed, resulting in decreasing biomass output rate when culture temperature went above 40°C. In cultures with temperature control, the quasi-steady-state output rate of all cultures increased throughout the day and leveled off in the late afternoon in high-density cultures. The daily area output rate was proportional to the density of the cultures. The specific growth rate of the light-limited cultures increased only marginally (20%) in the morning.