Integrated Model for Design, Optimization, Scale-Up, Culture Scheme, and Production Evaluation of a Bioreactor and Its Application for Improving Algal Biomass and Carbon Fixation in Bioreactors

A comprehensive numerical model system for the bioreactor design, structure and cultivation condition optimization, scale-up, and carbon fixation performance evaluation was proposed. Three basic models of computational fluid dynamics, particle and mass transfer, and two improved models of algae growth and light accumulation were integrated innovatively. The algae growth model directly predicted the algal production performance of the bioreactor, and the error was less than 15% compared with the experimental results. The light accumulation model was proposed to simulate the spatial distribution of light utilization with the changes of algal concentration and light intensity. The model system was applied to scale up the flat plate photobioreactor with inclined baffles, and the results showed that the photobioreactor with 9 cm light path had a maximum ideal areal productivity (505.94 g/m2) and better performance. Based on the light accumulation model, the strategy of changing the surface light intensity during the cultivation was proposed to maintain the light utilization and increase the production. Under the optimized surface light intensity, the maximum algal concentration and the average carbon fixation rate of the bioreactor were 43.41 and 248.35% higher than those of the constant light intensity. The proposed model system is a reliable and efficient experimental alternative tool for algal production evaluation and carbon fixation application of the bioreactor.