Optimization of Spinel Absorber Coatings for CSP Particle Receivers

In order to improve the current commercial plants of concentrating solar power system (CSP), new system designs are being explored within the framework of COMPASsCO2 project to reach high temperatures. Solid particles are potential candidates to be used as receiver in CSP plants to increase their operating temperature (in order of 1000 °C) and efficiency, while can be also used as thermal storage medium. So, the integration of CSP particle systems into a highly efficiency-CO2 Brayton power cycle for electricity production is pursued. Different kinds of particles developed by Saint-Gobain have been coated with new developed coatings in order to ensure good optical properties and study their high temperatures and abrasion resistance. Solar absorptance values as high as 0.98 are obtained by applying 4 layers of porous black copper, manganese and iron spinel, heated at 1000ºC. A system to study abrasion processes by particle-particle collisions was also presented.