Novel bioreactor with inclined baffles in cost-efficiently increasing algal biomass and carbon fixation

Abstract

We assess the cultivation of microalgae and possible improvements of photobioreactor (PBR) design and operation. A systematic method based on numerical modeling and experiments was proposed to guide the study of reactor performance. Taking the novel flat plate photobioreactor (FPPBR) with inclined baffles (IBs) as an example, the method was applied to investigate an effective way to improve the cultivation potential of the reactor. To obtain good mass transfer and light utilization, the optimal ratio of baffle opening gap to bioreactor width was 0.25. The algal biomass in the FPPBR with IBs at 3% CO2 aeration and an aeration rate of 0.05 vessel volume per minute (vvm) was 27.08% and 48.34% higher than that of FPPBR without baffles under the same cultivation conditions and higher air aeration rate of 0.15 vvm. The maximum carbon fixation rate increased by 106% when using the IBs under the same 3% CO2 aeration condition. The installation of the optimal IBs made it possible to achieve highly efficient cultivation under low energy aeration input, and it is also a cost-efficient way to increase carbon fixation in the bioreactor.