Development of dual strain microalgae cultivation system for the direct carbon dioxide utilization of power plant flue gas

Abstract

This study aims to propose a biological system that allows for direct utilization of flue gas for carbon dioxide capture and utilization by microalgae. The strain Chlorella sp. ABC-001 is employed for its high growth rate as well as lipid and carbohydrate content. Toxicity tests showed that cell growth was unaffected by NO, but the presence of SO₂ showed critical damage on cell growth. Hence, an extremophile alga, Galdieria sulphuraria 5587.1 was applied to build a dual-strain cultivation system to mitigate the effect of SO₂ toxicity and increase CO₂ capture efficiency. All SO₂ was removed by Galdieria culture and the system exhibited stable growth from a simulated flue gas stream containing CO₂, NO and SO₂. Combined CO₂ biofixation rate of 793 mg/L/d and lipid productivity of 113 mg/L/d was achieved. The results showed that this new cultivation system is a promising alternative for reducing CO₂ emissions from power plants.

Keywords: Biological CO(2) fixation; Dual strain cultivation system; Flue gas utilization; SOx removal.