Promotion of microalgal biomass production and efficient use of <scp>CO₂</scp> from flue gas by monoethanolamine

Abstract

Abstract BACKGROUND Flue gas as carbon source for microalgae culture has been applied to reduce the high cost of production. However, low mass transfer efficiency owing to the low CO 2 partial pressure in flue gas limited its utilization. In this work, monoethanolamine was proposed to enhance CO 2 utilization and microalgal biomass production . RESULTS In abiotic absorption experiments, the total inorganic carbon concentration in the medium increased with the increase of monoethanolamine concentration and the CO 2 absorptivity remained above 60% for a considerable pH range (6.5–10.0). The biomass productivity and lipid productivity of Scenedesmus dimorphus were enhanced with monoethanolamine ranging from 0 to 100 mg L −1 . When 100 mg L −1 monoethanolamine was added, the CO 2 utilization efficiency reached 76.1%, which was much higher than the 44.5% obtained in routine culture. The growth of cells was inhibited with monoethanolamine concentration exceeding 150 mg L −1 . The changes of net photosynthetic activity revealed that the oxygen evolving complex might be injured by the higher concentration of monoethanolamine . CONCLUSIONS These results indicated that the incorporation of monoethanolamine could be a promising solution to the problem of low CO 2 utilization efficiency and low biomass productivity in the microalgae culture system. © 2014 Society of Chemical Industry