Identification of the key structural parameters for the design of a large-scale PBR

Abstract

Although Photobioreactors (PBRs) are designed for industrial or experimental purposes, there are no standards for their design. PBRs are usually designed on the basis of the subjective decisions of researchers or producers, and most studies have examined small-scale PBRs. Furthermore, although it is important to enlarge the PBRs to obtain economic feasibility for microalgae production, the influence of each structural parameter on productivity in a large-scale PBR has not, to date, been fundamentally analysed. In this study, microalgae productivity according to the structural parameters (baffle and nozzles) was calculated and analysed using computational fluid dynamics (CFD) and the biomass production prediction grafting mixing and growth (BPMG) model. The influence of the structural parameters was then observed using statistical analysis. From simulation results, the microalgae productivity increased up to 90% depending on the installation condition of the baffle, although all the installation conditions of the baffle did not have a positive effect on the microalgae productivity. The installation depth (Bid) and the bottom clearance (Bc) values of the baffle as the main effects on the microalgae productivity were significant at the 99.9% confidence level. In addition, the influence of each structural parameter on the improvement of the microalgae productivity was evaluated, such that the t-values of the Bid, the Bc, and the number of nozzles (Nn) were found to be −8.437∗∗∗, −5.346∗∗∗, and 1.975, respectively. The interaction effect between the Bid and the Bc of the baffle showed a significant difference at the 95% confidence interval.