Based on advective-diffusive reaction equation for inhomogeneous biochemical system and an empirical equation for light attenuation coefficient, the interplay among culture parameters, light intensity and illumination condition, and mechanical mixing condition during O-2 evolution and H-2 production in a flat plate photobioreactor with sulfur-deprived Chlamydomonas reinhardtii culture is modeled in this work. Four initial chlorophyll concentrations, two light attenuation levels, and two illumination conditions were modeled to study their effects on the dynamics of O-2 evolution and H-2 production. The results indicate that two side illumination is the best design for light penetration into a flat plate reactor. While for single side illumination condition, an optimal combination of the initial cell concentration, light intensity, and reactor width may have to be considered for high H-2 production. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.