Center for Energy, University of Pittsburgh
positioning our region for the future.
Reuse of Treated Internal or External Wastewaters in the Cooling Systems of Coal-based Thermoelectric Power Plants
The overall research objective of this study is to assess the potential of using three different impaired waters—namely, secondary-treated municipal wastewater, passively treated coal mine drainage, and ash pond effluent, as cooling water in coal-based thermoelectric power generation. This project is designed to assess geographic proximity, pretreatment requirements, available quantities, and regulatory and permitting issues that are relevant for application of these impaired waters in cooling systems, as well as key design and operating parameters that would ensure successful use of these impaired waters without detrimental impact on the performance of the cooling system. Another important objective of the proposed work is to develop and demonstrate the efficacy of small, pilot-scale cooling towers for side-by-side evaluation of the use of impaired waters under different operating conditions. As consideration of alternative sources of water for cooling purposes increases in the years ahead, it will be important to have methods in place for rapid and accurate evaluation of performance of these waters in cooling systems.
Application and Benefits
Many thermoelectric power plants cannot be constructed where they are needed because they cannot obtain permits for cooling water from the existing surface waters. This obstacle can be overcome if they can secure their cooling needs using the proposed impaired waters.
The major benefits are to:
- develop new cooling water sources;
- ensure continuous development of new coal-fired power plants;
- improve economics of power generation;
- conserve water usage in power generation;
- develop strategies for controlling biofilm growth as well as strategies for controlling scaling and corrosion; and
- develop standardized protocols for testing new water sources for cooling use.
Study objectives will be accomplished through carefully combining pilot- and laboratory-scale studies with engineering and regulatory assessments and mathematical-modeling efforts. Pilot-scale cooling-tower systems will be operated for an extended period of time using real impaired waters at each of three sites selected for this study: municipal wastewater treatment facility, mine-drainage collection and treatment site, and coal-based thermoelectric power plant using sluicing systems to remove combustion residues from the plant. Laboratory studies to assess treatment technologies for blowdown from the pilot-scale cooling towers will be performed. Concentrations and reactions of chemical constituents in the impaired waters during cooling tower operation will also be evaluated through bench-scale experiments and chemical modeling. Modeling studies will be used to facilitate understanding of key aspects of the water-quality changes in the cooling-tower system and aid experimental work to reach maximum understanding of these complex processes.
Key Industry Partner
Other Industry Partners
Baltimore Air and Coil
U.S. Department of Energy
National Energy Technology Laboratory
Radisav D. Vidic
Professor and Chairman
University of Pittsburgh
Department of Civil and Environmental Engineering