H2 production by photofermentation in an innovative plate-type photobioreactor with meandering channels

Hydrogen production by Rhodobacter capsulatus is an anaerobic, photobiological process requiring specific mixing conditions. In this study, an innovative design of a photobioreactor is proposed. The design is based on a plate-type photobioreactor with an interconnected meandering channel to allow culture mixing and H-2 degassing. The culture flow was characterized as a quasi-plug-flow with radial mixing caused by a turbulent-like regime achieved at a low Reynolds number. The dissipated volumetric power was decreased 10-fold while maintaining PBR performances (production and yields) when compared with a magnetically stirred tank reactor. To increase hydrogen production flow rate, several bacterial concentrations were tested by increasing the glutamate concentration using fed-batch cultures. The maximum hydrogen production flow rate (157.7 +/- 9.3 ml H-2/L/h) achieved is one of the highest values so far reported for H-2 production by R. capsulatus. These first results are encouraging for future scale-up of the plate-type reactor.

Automated summary

Hydrogen production by Rhodobacter capsulatus requires specific mixing conditions and an innovative plate-type photobioreactor design with meandering channels has been proposed. The flow rate of hydrogen production was significantly increased by testing different bacterial concentrations and the maximum flow rate achieved was among the highest reported values for R. capsulatus, showing great potential for future scale-up of similar reactors.