Enhancement of CO 2 transfer and microalgae growth by perforated inverted arc trough internals in a flat-plate photobioreactor.

Flat-plate photobioreactor (PBR) with perforated inverted arc trough (PIAT) internals was proposed to promote CO ₂ bio-fixation by microalgae. The PIAT internals can enhance CO ₂ transfer from gas to culture medium by prolonging CO ₂ gas-liquid contact time and generate periodic aeration in the suspension upper side the PIAT providing suspension mixing. Experimental results showed gas-liquid contact time was prolonged from 0.448 s to 256 s and the CO ₂ partial pressure inside the PIAT internals was about 15.5 kPa during microalgae cultivation. Consequently, the dissolved CO ₂ concentration in the microalgae suspension of the proposed PBR was increased by 26.0% compared to that in the PBR without PIAT internals when 15% CO ₂ (v/v) was aerated at a rate of 15 mL min ^-1 . The elevated CO ₂ transfer contributed to a 20.9% increment in biomass concentration (3.35 g L ^-1 ) and a 26.2% increment in CO ₂ fixation rate (36.6 mg L ^-1  h ^-1 ).
(Copyright © 2018 Elsevier Ltd. All rights reserved.)