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

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 SO 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 SO toxicity and increase CO capture efficiency. All SO was removed by Galdieria culture and the system exhibited stable growth from a simulated flue gas stream containing CO, NO and SO. Combined CO 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 CO emissions from power plants.