Recovery Act - Brackish and Wastewater Cleanup for Process Cooling

Thermoelectric power plants and refineries use large quantities of water for cooling, placing large demands on conventional water resources. This is especially true in arid locations, where groundwater may be the only source. To ease the burden and free up conventional water resources for agricultural and potable water use, there is increasing interest in developing technologies that could allow thermoelectric power generating stations to use unconventional, brackish water that is unfit for agriculture or potable water use, for process cooling. Unfortunately, depending on the source, these brackish waters contains dissolved salts and other contaminants in the range of several thousand parts-per-million, which must be removed to make these waters suitable for cooling tower makeup water. TDA Research Inc., is developing a capacitive deionization (CDI) process that makes use of our inexpensive, high surface area, high capacity, and adjustable pore size electrodes. With our electrode technology, we can tune the properties of the electrodes to maximize their performance to process many types of brackish water, or a particular feed. Our technology is considerably less expensive than competing technologies such as ion exchange and reverse osmosis.In Phase I, TDA designed and built a CDI electrochemical cell and demonstrated that our proprietary electrodes have high capacities for removing dissolved salts in simulated brackish water. In addition, no degradation was observed after an eightycycle test, indicating that the electrodes are durable. In Phase II, TDA will optimize the electrodes and the process conditions for CDI, and then design, build and test of a prototype unit with several real brackish water samples. The prototype will be tested at TDA and by our industrial partner at their facilities. The successful demonstration of the prototype will give use valuable data for designing and demonstrating a pilot scale test unit in Phase III. Commercial Applications and Other Benefits: We estimate that even with only 20% market penetration, our technology can save enough water on an annual basis to continuously supply 6.5 million people with fresh water.