Experimental investigation of Directly Irradiated Fluidized Bed Autothermal Reactor (DIFBAR) for thermochemical processes

The integration of Concentrating Solar Thermal technology (CST) with thermochemical processes is regarded as a frontier innovation, with potential applications to energy storage and chemical industry. In this context, the development of novel multiphase reactors for CST becomes a strategic goal. This study aims to investigate the potentiality of a Directly Irradiated Fluidized Bed Autothermal Reactor (DIFBAR), that incorporates a solar particle receiver/reactor and a solid-solid heat exchanger for heat recovery. A laboratory prototype is tested with a high-flux solar simulator. The bed inventory is continuously recycled to a reservoir, that can also be operated as a secondary reactor. Black proppant, mullite and doped silica are used for inert experiments. Solid circulation rates in the range 0.5–2.5 g/s and heat transfer coefficients in the range 300–900 W/(m2 K) are estimated. Calcium Looping process is chosen for reactive experiments, using a mixture of limestone and black proppant.