摘要
A bionic fractal tree-like photobioreactor (PBR) with multiscale bubbles was studied to help intensify gas-liquid mass transfer and the microalgal photosynthesis. A numerical simulation and several experiments were conducted to study the hydrodynamic characteristics of the microbubbles (MBs) and large bubbles (LBs) in the tree-like PBR. The characteristics studied included the bubble size distribution, flow pattern, gas holdup, gas-liquid slip ratio, and turbulence. The good flow characteristic of the MBs tended to generate a homogeneous dispersed flow pattern, which intensified the synergistic effect of flow and light fields based on the long residence time, large gas-liquid contact area, and even multiphase mixing in the large-area illuminated fractal reactor. As a result, the photosynthetic capacity and microalgal activity were enhanced by combining the tree-like PBR with MBs, providing a novel valuable technical solution for improving the multiphase photoreaction. (c) 2020 Elsevier Ltd. All rights reserved.
