BACKGROUND: CO2 is the primary impurity in many fuel gases and may reduce the efficiency of fuel combustion and generate incomplete residues in the product, leading to energy waste and environmental issues after emission. Currently although plants/microalgae-mediated approaches have been widely used for CO2 separation/digestion, they usually emphasize CO2 removal efficacy for the purpose of environment protection, but give less consideration to subsequent CO2 manipulation for cell culture that restricts their effectiveness thereafter. To address the above issues, a perfluorinated photobioreactor system (PPBRS) enabling CO2 separation and controlled microalgae cultivation was developed in this study. RESULTS: Results showed that the PPBRS provided >85% CO2 separation efficiency from 60%-N2/40%-CO2 within 5 days by using perfluorocarbon as the CO2 absorbent. Nannochloropsis oculata cultured with 20 mL min-1 perfluorocarbon containing 2% CO2 isolated from the gas mixture exhibited 2-fold higher cell concentration and yielded 1.8-, 2.5-, and 2-fold (P < 0.05 for all) increased productions of biomass, lipid, and eicosapentaenoic acid, respectively, compared with the group with air aeration without PFC for 5 days. CONCLUSION: Perfluorocarbon is recyclable and all procedures including CO2 extraction, collection of purified gas, and delivery of isolated CO2 to cell culture are a continuous process without need for additional handling. The PPBRS thus provides an efficacious, easy-to-use, and cost-effective means for simultaneous CO2 separation and enhanced microalgae production that can be applied for use in industry.
- CO separation