100 kWe power generation pilot plant with a solar thermochemical process: design, modeling, construction, and testing

Abstract

Using concentrated solar thermal energy to drive endothermic thermochemical reactions offers promising prospects for the efficient utilization of solar energy by upgrading solar energy to high-quality chemical energy. A 100 kWe power generation pilot plant with mid-and-low temperature solar thermochemistry is designed, modeled, constructed, and tested in this work. The mid-and-low temperature solar thermochemistry and power generation are investigated experimentally, and successfully integrated operation is achieved for the first time. In the pilot plant, solar energy is upgraded into the chemical energy of solar fuel (H2 and CO) through the solar thermochemical process of the methanol decomposition reaction. The solar fuel is then fed to an internal combustion engine to generate power, achieving efficient and stable conversion of solar energy to electricity. The solar generation pilot plant is constructed, including four solar thermochemistry units (with a solar field area of 198 m2), power generation unit (100 kWe), syngas storage unit (with a volume of 19.2 m3), preheating unit, and measurement instrumentation. The thermodynamic performance of the pilot plant is tested under varying solar irradiation levels and power loads. The catalyst bed temperature distribution, methanol decomposition rate, and solar-to-chemical energy efficiency are experimentally investigated. The solar thermochemistry generates with catalyst bed temperatures of 70–290 °C, and a methanol conversion rate exceeding 80% is achieved. The solar-to-chemical energy efficiency is in the range of 37.12–45.51% for solar fluxes of 404–761 W/m2. The system achieves an electrical efficiency of 24.73%, and it can provide a fuel saving of 16.71% compared with direct methanol combustion systems.