Demonstration of an Algae-based System for CO2 Mitigation from Coal-fired Power Plants

Given the potential of microalgae for mitigating coal-fired power plant emissions, the Commonwealth of Kentucky Department of Energy Development and Independence (KY DEDI) tasked the University of Kentucky (UK) in late 2008 with determining the technical and economic feasibility of algae-based carbon capture in Kentucky. The current UK-led project (“Demonstration of an Algae-Based System for CO2 Mitigation from Coal-Fired Power Plants”) is focused on the design, construction, and demonstration of an algae-based CO2 mitigation process suitable for use at Kentucky power plants. The overall goal of this project is to design a process capable of utilizing the flue gas through operation of a continuous microalgae culture (selected for its ability to flourish in the relevant conditions), harvesting a sustainable quantity of the algae, and converting harvested algae into a value-added product (e.g., fuel for co-firing, biooil for conversion to biodiesel, bio-gas, or a nutritional additive for animal feed). The unique nature of our concept is that we are designing the cultivation and processing system to suit the CO2 source, as opposed to allowing the cultivation system to dictate the source which has been the general direction of most comparable studies. Our efforts have resulted in the development of a low-cost, closed-loop photobioreactor coupled with a low-energy biomass recovery strategy using flocculation and sedimentation. One of these photobioreactors (~5500 liter), shown in Figure 1, is currently operating within our greenhouse facility at the UK Center for Applied Energy Research.