Waste-heat-to-power (WHP) recovers electrical power from exhaust heat emitted by industrial and commercial facilities. Waste heat is available in enormous quantities. The U.S. Department of Energy estimates 5-13 quadrillion BTUs/yr with a technical potential of 14.6 GW are available and could be utilized to generate power by converting the heat into electricity. The research proposed here will define a system that can economically recover energy from waste heat through a thermal regenerative electrochemical system. The primary motivation came from a patent and the research sponsored by the National Renewable Energy Laboratory (NREL). The proposed system improves on this patent in four major ways: by using air/oxygen, rather than hydrogen; by eliminating the cross diffusion of counter ions and using a dual membrane cell design; and by using high concentrations of electrolytes that have boiling points below water. Therefore, this system also works at difficult-to-recover low temperatures. Electrochemical power is estimated at 0.2W/cm2, and for a 4.2 M solution at 1 L/s, the power of a 100 kW system is 425 kW. Distillation energy costs are simulated and found to be 504 kJ/s for a 1 kg/s feed stream. The conversion efficiency is then calculated at 84%. The Carnot efficiency for a conservative 50% conversion efficiency is compared to the ideal Carnot efficiency. Preliminary work suggests an LCOE of 0.6ยข/kWh. Industrial energy efficiency could be boosted by up to 10%. Potential markets include power stations, industrial plants, facilities at institutions like universities, geothermal conversion plants, and even thermal energy storage.
| Identifer | oai:union.ndltd.org:unt.edu/info:ark/67531/metadc1808390 |
| Date | 05 1900 |
| Creators | Gray, David B |
| Contributors | Choi, Tae-Youl, Choi, Wongbong, Zhao, Weihuan |
| Publisher | University of North Texas |
| Source Sets | University of North Texas |
| Language | English |
| Detected Language | English |
| Type | Thesis or Dissertation |
| Format | vii, 54 pages, Text |
| Rights | Public, Gray, David B, Copyright, Copyright is held by the author, unless otherwise noted. All rights Reserved. |
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