Catalytic ozone decomposition in a high density circulating fluidized bed riser

Reactor performance of a high density circulating fluidized bed (CFB) riser is studied using ozone decomposition with extremely high solids circulation rates up to 800 kg/m²s and superficial gas velocities ranging from 5 to 9 m/s. Results show that the axial and radial distributions of the ozone concentration are consistent with those of the solids holdup. Higher solids flux and/or lower gas velocity lead to higher reaction conversion in the riser. Solids holdup is the dominant factor affecting reaction conversion. Effects of solids holdup on overall ozone conversion are more significant under high superficial gas velocity and/or low solids circulation rate. Overall conversion in the high density riser is not only less than that of plug flow reactor but also less than that of completely stirred tank reactor indicating that, due to the two-phase nature inside the riser, a CFB riser is still far from an ideal plug flow reactor.