Light-limited continuous culture of Chlorella vulgaris in a Taylor vortex reactor

Recently, it has been demonstrated that Taylor vortices - hydrodynamic structures that arise in the annular region between two concentric cylinders when the inner cylinder rotates - can substantially improve the growth rate of algal biomass in a batch photobioreactor by inducing the flashing light effect. In order to assess the potential for using Taylor vortex flow to continuously culture algae, experiments were carried out in a continuous flow Taylor vortex algal photobioreactor using Chlorella vulgaris. Specifically, two important operating parameters were varied: the dilution rate and the inner cylinder rotation speed. For a fixed inner cylinder rotation speed, biomass productivity was independent of dilution rate. In contrast, biomass productivity was found to increase with increasing inner cylinder rotation speed for a fixed dilution rate, but this effect became less pronounced at higher rotation speeds. Overall, it is demonstrated that a continuous flow Taylor vortex algal photobioreactor can be used to produce and sustain high biomass production and carbon dioxide capture rates when operated in continuous flow mode. © 2013 American Institute of Chemical Engineers Environ Prog, 32: 884-890, 2013