A fluid-solids contactor comprising an annular rotating fluidized bed and a method of using the same are disclosed. The fluid-solids contactor includes a vessel and a plurality feed inlets disposed thereon. The vessel comprises a stationary inner wall, an outer wall, and a chamber formed between the stationary inner wall and the outer wall. The feed inlets are configured to create an annular rotating bed with mixture of solids and a fluid when the solid particles and a fluid are fed into the chamber. The stationary inner wall of the vessel is permeable to the fluid such that the fluid from the chamber can be continuously withdrawn from the solids to the space within the stationary inner wall of the vessel.