Improving the Economic Viability of Biological Utilization of Coal Power Plant CO2 by Improved Algae Productivity and Integration with Wastewater Treatment
- University of Illinois at Urbana-Champaign, Urbana, IL (United States)
- Helios-NRG, LLC, East Amherst, NY (United States)
The overall goal of this project was to improve the cost-effectiveness of systems using algae to capture and beneficially utilize CO2 from the flue gas of coal-fired power plants. Algal biomass cultivation is an attractive alternative for carbon capture and utilization because it can uptake more CO2 per land area than any other photosynthetic crop. Also, the resulting biomass can be used to make valuable large-market commodity products, such as biofuels and animal feed. However, the use of algal carbon capture has been limited by several factors including: (1) high costs for growing algae (>$$\$$1,300$/ton), (2) large land requirements for algae cultivation, and (3) environmental concerns about the large amount of water and nutrient inputs needed for growing algae. This project has taken direct aim at resolving these key limitations and demonstrated several viable approaches to improve the economic and environmental feasibility of algal carbon capture. In particular, this project demonstrated a significant increase in average annual algal productivity from baseline values of 8 g/m2-day to above 20 g/m2-day. This supports a much lower projected cost of algae production (<$$\$$500$/ton) and reduces land requirements by more than 50%. Additionally, this project confirmed the ability to grow multiple algae species with wastewater nutrients, which facilitates the potential for substantial new revenue streams for algae cultivation based on tipping fees for nutrient laden wastewater. This study highlighted that there is more potential value in wastewater nutrient treatment credits than in the primary commodity products made from algae. The use of wastewater inputs also mitigates the concerns associated with the large amount of water needed for growing algae. The algal biomass grown for this project using wastewater and simulated flue gas inputs were characterized for potential use as an animal feed ingredient. The algae had a protein content in the range of 35-40%, which is between some common commodity animal feed products— distiller’s grains (~25-30% protein) and soybean meal (45-50% protein). In-vitro digestion tests using cattle rumen fluids, showed that this algae biomass was best suited for use as “bypass protein”, which is digested in the animal intestine. Based on the protein content and amino acid profile of the algae grown in this study, it was estimated to have market value in the range of $$\$$190$$-$$\$$280$/ton. There is potential for higher value feed products if the algae content of omega-3 fatty acids or antioxidants is accounted for. This project also did small scale demonstration of forward osmosis algae dewatering and nanofiltration of hydrothermal liquefaction aqueous products, which were shown to improve the cost and energy balance for producing algal products. When all the improvements demonstrated in this study were included in techno-economic analysis, it showed there was a viable pathway to profitable algal CO2 utilization with a payback period in the range of six to ten years.
- Research Organization:
- University of Illinois at Urbana-Champaign, Urbana, IL (United States)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE); USDOE Office of Environmental Management (EM), Regulatory and Policy Affairs. Waste and Materials Management; USDOE Office of Fossil Energy (FE), Petroleum Reserves; USDOE Office of Fossil Energy (FE), Clean Coal and Carbon Management
- DOE Contract Number:
- FE0030822
- OSTI ID:
- 1887581
- Report Number(s):
- DOE-UIUC-30822
- Country of Publication:
- United States
- Language:
- English
Similar Records
Biofuels from Microalgae: Review of Products, Processes and Potential, with Special Focus on Dunaliella sp.
Development Of Nutrient And Water Recycling Capabilities In Algae Biofuels Production Systems. Final Summary Report