Precalciner Geometry Optimization Considering H2O and CO2 Heat Transfer Fluid for Cement Production

The cement industry accounts for 3 – 5% of global CO2 emissions and is difficult to decarbonize due to the high temperature used in the process. The cement raw material requires temperatures up to 900 ℃ for calcination and 1500 ℃ for sintering. Synhelion has developed an absorbing-gas solar receiver which can provide 1500 °C heat to the process via an H2O/CO2 heat transfer fluid to provide fossil-free heating for the preheating and calcination stages. However, very little work has been done to investigate the viability of solar-heated H2O and CO2 gases to efficiently calcine the cement raw meal relative to conventional gas-fired precalciners. The objective of this study is to present an optimized small scale precalciner considering particle suspension, flow dynamics, heat transfer, and thermochemistry of the raw meal when using H2O and CO2 gases. The optimization of the precalciner geometry using a CFD model developed in ANSYS is presented.