Conceptual design of a hybrid thin layer cascade photobioreactor for microalgal biodiesel synthesis

Abstract

Even though microalgae are able to produce various valuable metabolites, microalgal culture on an industrial scale still faces challenging difficulties. Open systems may be cheaper to construct, easier to operate and maintain, and possess greater surface area to volume ratio, but they are also easily contaminated, have high water loss due to evaporation, and suffer from unfavorable weather. On the other hand, closed photobioreactor systems possess higher biomass yields, better control over culture parameters, and lower contamination risks. However, photobioreactors are costlier to construct and maintain. Thus, a hybrid semi-closed thin layer cascade photobioreactor was proposed to cultivate high-density microalgal cultures for biodiesel production. Computational fluid dynamics analysis was carried out to observe fluid behavior in the hybrid photobioreactor design. The simulation results showed satisfactory performance in the improved design, making the photobioreactor a potential candidate for microalgal biodiesel production.

Novel Thin-Layer Fountain Photobioreactors for the High-Density Cultivation of Spirulina sp

“…However, as a preliminary work, the TLF-PBR with a layer depth of 1.1 cm achieved a lower average areal productivity (4.622 g m –2 day –1 ) than that of the flat panel PBR with a high depth of 5.0 cm (8.277 g m –2 day –1 ) during the 10-day cultivation, but it was higher than that of the TLCS with the same depth (3.588 g m –2 day –1 ). Although the flat panel PBR achieved high areal productivity, its commercial application is seriously limited due to its high mixing energy inputs and costs, small cultivation scales, and extremely high manufacturing cost . Compared with flat panel PBR, the TLF-PBRs have great advantages of high cell density and low operating culture volume, large cultivation scales, low manufacturing costs, and energy inputs (Figure ), holding great potential in achieving lower microalgal production costs than flat panel PBR.…”

“…Additionally, as an open cultivation system, the TLCS features a high contamination risk, rapid water evaporation rate, and difficulty in controlling cultivation conditions. 19 Herein, we report a novel mixing-based thin-layer fountain PBR (TLF-PBR) with a simple structure for high-density microalgal cultivation (Figure 1a,1b); a fountain pump is used to pump and spray the microalgal culture for mixing. To achieve a thin-layer depth for efficient microalgal cultivation, the fountain pump is deployed into a sump.…”

Crossing and selection of Chlamydomonas reinhardtii strains for biotechnological glycolate production

“…Ultimately, the concept of generating bioenergy from microalgal biomass can only be economically feasible if other valuable co-products are utilized (Khanum et al 2020 ). Several recent papers have also discussed this challenge and proposed ways to overcome it, such as careful selection and optimization of strains (Kong et al 2019 ; Sproles et al 2021 ), optimized photobioreactor design (Deprá et al 2019 ; Tan et al 2020 ; Legrand et al 2021 ), and improved economical harvesting and processing methods (Li et al 2020 ; Liber et al 2020 ).…”

Optimization of microalgal biomass and lipid productivities for bioenergy production using central composite design with desirability function

“…[6][7][8][9][10] It is a noteworthy aspect that lipid amount in microalgae biomass is a key parameter for production of biofuel yield. 6,[11][12][13] Worth mentioning that there are several thousands of microalgae species available in the nature. However, all of them may not be good source of lipids.…”

“…In this regard, biofuels from non‐food sources including microalgae biomass considered as a potential feedstock 6‐10 . It is a noteworthy aspect that lipid amount in microalgae biomass is a key parameter for production of biofuel yield 6,11‐13 . Worth mentioning that there are several thousands of microalgae species available in the nature.…”