CFD modeling of CO2 fixation by microalgae cultivated in a lab scale photobioreactor
Ulla Ojaniemi, Anu Tamminen, Jouni Syrjänen, Dorothee Barth
Abstract
• A CFD model for CO 2 fixation by Chlorella vulgaris cultivation has been presented. • A model for algae growth dependency on excess and shortage of dissolved CO 2 . • Verification done with experiments in laboratory scale stirred jacketed reactor. • The model serves as a valuable tool for evaluating photobioreactor performance. The green microalga Chlorella vulgaris has been studied for efficient fixation of carbon dioxide, CO 2 , from elevated concentrations of in-feed gas flows. In this work, a Computational Fluid Dynamics (CFD) model for algae cultivation including the dependence on CO 2 concentration in liquid has been derived based on cultivation experiments of Chlorella vulgaris . The experiments were performed in a laboratory scale cylindrical stirred tank reactor with a range of enriched CO 2 concentrations in-feed (0.04–50 %). The model provided by Béchet et al. (2015) for algae cultivation considering dependence on local light, algae concentration and temperature has been implemented for CFD and modified for comprising CO 2 dependence. The model has been verified with experimental results for the algae productivity showing the proper trends for dissolved CO 2 concentrations and algae concentrations. Thus, the developed CFD model can serve as a tool for evaluating photobioreactor performance for CO 2 capture.