Assessing Cooling Tower PM2.5 and PM10 Emissions using Advanced Instrumentation, Plume Transects, and Plume Modeling
Assessing the particulate matter emissions from cooling towers using both brackish and freshwater.
Regents of the University of California, Davis
Recipient
Davis, CA
Recipient Location
3rd
Senate District
4th
Assembly District
$687,298
Amount Spent
Completed
Project Status
Project Result
The research team has completed measuring particulate matter (PM) in the cooling tower plume at three operating power plants. A third power plant was added to allow for sampling at a cooling tower with brackish water. The team analyzed the data collected from the plume measurements and developed a model to allow power plant operators and regulatory agencies to accurately estimate PM emissions from cooling towers. The project final report has been submitted for review.
The Issue
Concerns over limited freshwater supplies have resulted in state policies encouraging the use of degraded water in cooling towers for recently approved thermal power plants. Cooling towers using degraded water sources, which contain high concentrations of total dissolved solids, will have higher particulate matter (PM) less than 10 micrometers in diameter (PM10) emissions that require the purchase of additional costly PM offsets. These emissions are a significant issue for power plant developers and may discourage the use of degraded water sources for cooling.
Project Innovation
Current methods estimating PM emissions from cooling towers are rough approximations and most likely overestimate those emissions. This leads to power plant operators pursuing more expensive PM reduction than may actually be required. This project measured PM2.5 and PM10 across the spray drift plume from two power plant cooling towers that use fresh water and brackish water. These measurements were used to develop and validate a model of power plant PM2.5 and PM10 emissions that provides power plant operators and air quality agencies a methodology to accurately estimate PM2.5 and PM10 emissions of brackish water use in cooling towers.
Project Goals
Project Benefits
The research team used plume measurements from fresh and brackish water-cooling towers to develop a model of the droplet and particle size distribution changes in cooling tower plumes as a function of cooling water composition, meteorological conditions, and cooling tower operating parameters. The model is based on first principles of chemistry and physics and was validated using the field measurement data. The model supports the use of brackish water instead of expensive fresh water, leading to decreased costs for electric utilities and ratepayers and freeing up more fresh water for use in homes, industry, and agriculture in California.
Affordability
This project decreases power plant operating costs by enabling the switch from fresh water to brackish water in cooling towers, saving money in facilities operations, since brackish water is less expensive than fresh water.
Environmental Sustainability
This research shows that particulate matter emissions from cooling towers, even those using brackish water is quite low. In fact, cooling towers may actually reduce actually reduce ambient particulate matter levels.
Key Project Members
Anthony Wexler
Subrecipients
The Regents of the University of California, Santa Cruz
Match Partners
