Energy-Scavenging Thermogalvanic Cells for Improved Efficiency of Coal-Fired Power Plants and Post-Combustion Carbon Capture Systems via Waste Heat Utilization - Topic 8

This is a continuation to complete an already funded project paired in conjunction with an additional proposal based on the results and success of the previous grant (PON2 127 1300001707). In line with energy efficiency improvement initiatives for Kentucky (Strategy 1 and 6), we propose a thermal energy harvesting system which can scavenge the ubiquitous “waste heat” in coal-fired power plants, transduce the energy into electricity, and re-inject it as supplementary power for various plant processes. As an example, it will make carbon capture system (CCS) more economically feasible by reducing the parasitic energy load drawn from coal-fired power plants for amine circulation pumps, CO2 compressor etc.. This low maintenance and easy to implement technology will bring about significant increases in the efficiency of CCS and indeed overall energy conversion efficiencies in Kentucky’s coal industry. The technology provides autonomous power in the form of zero-emission electricity, operating wherever a temperature differential between the two sides of our device exists. The device is an electrochemical cell with specialized passive components which deliver power to a load whenever one side is hotter than the other. It is thus easy to envision wrapping modules of our thermogalvanic (TG) cells around various equipment in a coal-burning power plant where thermal energy is being dissipated from e.g. a vessel, and inevitably lost to the atmosphere as “waste heat”. Energy conversion efficiencies is typically in the range from 37 to 45% for coal-fired power plants depended on the steam conditions. The majority of this energy loss is attributed to “wasted” steam condensation which is rejected to recycled cooling water. Some power generation technologies can increase efficiency by recycling heat in “combined cycle” type generators, but coal-fired plants are less amenable to this process. For coal to remain a viable fuel source for electricity generation in Kentucky – in the face of dropping costs of natural gas and imminent EPA regulations – CCS retrofits may be necessary. If funded, the research will focus on nanostructured carbon materials with high surface areas to be used in electrodes for TGs. The cells harvest low grade heat (