(246a) Transient Heat and Mass Transfer Model of a Solar Thermochemical Reactor for CO2 Capture
A dual–cavity solar thermochemical reactor for carbon dioxide capture using the CaO carbonation—calcination cycle is under development. During the first step of the cycle, the exothermic carbonation, a packed bed of CaO particles in the reactor captures CO2 from a dilute stream such as from a power plant. In the second step, the endothermic calcination, the beam up reactor accepts concentrated solar energy through a windowless aperture at the bottom. The radiation is absorbed by the cavity walls and transferred via conduction to the reacting packed bed of particles in the outer cavity, releasing CO2 in a concentrated stream and regenerating CaO. To support refinement of the reactor design, a transient heat and mass transfer model has been developed using ANSYS Fluent to solve the continuity, momentum, and heat transfer equations coupled to a custom Monte Carlo ray tracing routine that determines radiation heat transfer in the reactor cavity. Transient temperature and velocity profiles and chemical reaction conversion in the reactor are presented.