A rotor assembly for a rotary feeder apparatus may include a hollow central shaft, a plurality of circumferentially spaced blades extending generally radially from the hollow central shaft partially forming a plurality of compartments, and at least one valve element associated with an opening formed in a wall of the central shaft. A rotary feeder apparatus may include a housing, a material inlet and outlet, and a rotor assembly. A stationary cam may be disposed within the hollow central shaft of the rotor assembly and a surface of the cam may displace a valve element. Methods of operating a rotary feeder apparatus may include loading a particulate material into a compartment of a rotary feeder, rotating the compartment, supplying a gas to the compartment through an opening in a wall of the hollow central shaft in communication with the compartment, and unloading the particulate material from the compartment.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 This invention was made with government support under Contract No. DE-AC07-05ID14517 awarded by the United States Department of Energy. The government has certain rights in the invention.