Micro Encapsulated Phase Change Material for the Application in Thermal Energy Storage

Abstract The pursuit of CO2 reduction targets has increased the need of storage capacities for renewable energy or thermal energy to enhance the efficiency of industrial processes. To combine the benefits of latent and sensible thermal energy storage systems, the concept of micro encapsulated phase change material is presented. The microparticles are designed to work in a high-temperature thermal energy storage system considering economic and technical points of view. Therefore, particles of sodium nitrate are physio-mechanical coated with polyimide by using spray-drying in a fluidized bed reactor. To evaluate the influence of the process conditions, several coating experiments with different process settings are performed. Afterward, the samples are analyzed to determine their properties. Besides a microscopic and a sieving analysis, they are tested in the laboratory to define their mechanical and thermal limits. Finally, a rough layout of a thermal energy storage system using the produced particles is presented and compared to a common sensible thermal energy storage.