Integrated High Operating Temperature Heat Storage System for Process Waste Heat

Industrial manufacturing processes consume vast amounts of heat. The most common source of heat generation used by the manufacturing sector is coal, natural gas, and petroleum. These industrial processes operate at higher temperatures and waste more than 50% of the total heat to the environment. This loss of high temperature and high-quality heat not only has negative economic impact but also contributes significantly to the carbon emissions, in the United States. To tackle this problem, in Phase II, Advanced Cooling Technologies (ACT), Inc. proposes to develop integrated high operating temperature storage (HOTS) system that uses metal (aluminum) as the phase change material for the storage and reutilization of industrial waste heat. In Phase I, Advanced Cooling Technologies Inc. in collaboration with Rutgers University successfully demonstrated HOTS prototype development. The proposed HOTS concept uses aluminum as the phase change material choice for higher operating temperatures (~660 °C) and higher latent thermal energy storage capacity. ACT in Phase I tackled the biggest challenge of using metal as phase change material by developing novel ceramic and coatings-based solutions for storing highly corrosive aluminum. In addition, ACT’s novel method of using vapor chamber for cancellation of thermal gradients and thermal shocks to ceramic/coating-based storage of aluminum adds to the overall structural integrity of the system. In addition, ACT plans to further develop the novel alkali metal heat pipes used for passive and isothermal heat transfer to and from the system at higher temperatures in the proposed Phase II program. Building on the successful demonstration of the HOTS prototype in Phase I, ACT in collaboration with Rutgers University proposes to further develop the HOTS concept for larger storage capacity and higher heat transfer capability. This will include the development of novel coatings and ceramic encapsulation structures for long-term corrosion resistant performance against molten aluminum exposure. In addition, the development of thermal battery units that contain aluminum phase change material placed inside a vapor chamber and the method of passively transferring heat with heat pipes will be conducted in Phase II for the desired energy storage capacity and heat transfer rate. Phase II program will also include the design of a larger HOTS system that can match to the waste heat storage and reutilization requirement of the manufacturing industry such as steel, aluminum, chemicals etc. In addition, ACT will conduct technoeconomic analysis to understand the viability of the proposed technology in the energy storage and reutilization capacity in comparison to existing state-of-the-art technologies. Proposed HOTS technology will offer means of storing and reutilizing high temperature waste heat. The primary commercial applications that benefit from the proposed technology are the manufacturing industries owing to their higher temperature operations and high heat losses. The manufacturing of metal (e.g., steel, aluminum), chemicals (e.g., Methanol, Ethelene, Nitric acid), cement/concrete, glass are the primary candidates for the use of the proposed HOTS technology. In addition, the proposed technology can be beneficial to reutilization of the stored high temperature heat for lower temperature application such as power plants, conventional furnace operations, steam boilers etc.