PHOTOSYNTHETIC CO2 MITIGATION USING A NOVEL MEMBRANE-BASED PHOTOBIOREACTOR

Biological carbon control, or photosynthesis, offers many advantages. Biomass developed from photosynthesis has numerous beneficial uses, including a potentially renewable source of biodiesel and other biofuels. It also offers potentially very low operating costs compared to other CO2 separation processes for coal-fired power plants. The work presented here, partially funded by the Department of Energy, describes the design and development of an engineered photobioreactor for CO2 recycling. The objectives of this study were: (1) to build a pilot-scale prototype of the membrane-based photobioreactor; (2) to demonstrate its operation and performance the thermophilic Chlorogleopsis; and (3) to characterize the growth and CO2 assimilation of Chlorogleopsis at different light levels. Results of testing using a strain of Chlorogleopsis isolated by Dr. Keith Cooksey of Montana State University have indicated that thermophilic cyanobacteria can grow in a sustainable, continuous fashion via photosynthesis using only solar power in saturated flue gas. The results also indicate that suspension of viable thermophilic organisms on vertically-suspended growth surfaces drastically reduces overall system footprint compared to the equivalent purely aquatic system. Further, coupling a full-spectrum, solar-tracking photon collection and delivery system via fiber optics allows the bioreactor to optimize growth and further reduce system footprint. Finally, coupling the delivery of water (during normal growth phase) and harvesting systems into the same fluid delivery mechanism has facilitated improved growth rates, while reducing system costs.