Microalgae have piqued renewed interest as a sustainable biofuel feedstock owing to their high CO2 conversion efficiency. However, the major limitation of microalga-based biofuel production is low productivity. In this study, CO2 in flue gas emitted from the coal-fired power plants was fixed through mass microalgal cultivation using only sunlight as an energy source. To minimize the cost and energy required to supply the flue gas and efficiently utilize the microalgal biomass, a polycarbonate (PC) greenhouse and polymeric photobioreactors were installed near the power plant stack. Four different microalgal strains (Chlamydomonas reinhardtii, Chlorella sorokiniana, Neochloris oleoabundans, and Neochloris oleoabundans #13) were subjected to semi-continuous culturing for 1 month. The maximum biomass productivity was achieved by the N. oleoabundans #13 strain (0.703 g L−1 day−1). Additionally, polymerase chain reaction analysis revealed that the individual microalgal culture was not cross-contaminated with other microalgal cultures in this cultivation system, owing to the structural properties of photobioreactor comprising individual modules. The lipid content and calorific productivity of N. oleoabundans #13 biomass were 45.70% and 3.553 kJ L−1 day−1, respectively, which indicate satisfactory performance of biomass as a direct combustion fuel. The CO2 fixation rate, which was calculated based on the carbon content in the biomass, was 0.309 g CO2 L−1 day−1. Therefore, large amounts of CO2 can be reduced using the large-scale microalgal cultivation system, which enables efficient biological CO2 conversion and maximizes microalgal biomass utilization.
Bibliographical noteFunding Information:
This work was supported by the Korea CCS R&D Center (Korea CCS 2020 Project) of the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT of Korea [Grant number 2014M1A8A1049278] and the Korea Institute of Energy Technology Evaluation and Planning (KETEP) Grant funded by the Korean government (Ministry of Trade, Industry and Energy) [Grant number 20172010202050].
© 2020, Jiangnan University.
- CO conversion process
- Coal-fired power plant
- Direct combustion fuel
ASJC Scopus subject areas
- Applied Microbiology and Biotechnology
- Food Science
- Biochemistry, Genetics and Molecular Biology (miscellaneous)