H-2 has the highest energy density among the other known fuels (143 GJ tonne(-1)). The present study is focused on spatial aspects of light patterns. Here, Rhodopseudomonas palustris strain DSM 123 was used for biohydrogen production in the triple jacketed photobioreactor (working volume 1 L) with light intensity (15 +/- 1.1 W m(-2)), temperature (33 +/- 1) degrees C, initial pH (6.7 +/- 0.1), inoculum volume 10% (v/v), and 250 rpm stirring. Three factor three level full factorial designs was used to optimize the concentration of three critical medium components DL malic acid, L glutamic acid and FeCl3 having high impacts on H-2 production. Surface and contour plots of the regression models revealed optimum H-2 production rate of 6.885 mL H-2 L-1 h(-1) showing correlation with experimental optimum H-2 production rate of 7.0 mL H-2 L-1 h(-1). In photobioreactors, turbulent flow conditions and light gradients may occur. CFD simulation study confirmed the advantages of designed annular PBR towards uniform fluid dynamics and heat transfer throughout the reactor. Mathematical modeling on substrate utilization for biomass and kinetics of substrate consumption for H-2 production by PNS bacteria gave good simulated results. Modified Gompertz equation yielded good simulated fitting with experimental value for H-2 production by Rhodopseudomonas palustris DSM 123. Copyright (C) 2016, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.