A system for reduction of organic materials, comprising: an infeed module for receiving material comprising organic materials and conveying the material into a reducing atmosphere, the infeed module comprising an infeed conveyor, for conveying the material through the infeed module, at least one purge chamber, a first closure for isolating the at least one purge chamber from an ambient atmosphere outside the system, a gas injection system in communication with the at least one purge chamber, for injecting a reducing gas to displace air from the at least one purge chamber to create a reducing atmosphere having a lowered concentration of oxygen in the at least one purge chamber, a microwave tunnel, the microwave tunnel being in sealed communication with the infeed module for isolating the microwave tunnel from the ambient atmosphere outside the system, the microwave tunnel comprising a microwave-impervious microwave chamber comprising a plurality of magnetrons for generating microwave radiation and at least one port for removal of process gas products, and a tunnel conveyor for receiving the material from the infeed module and transporting the material through the microwave chamber, at least a second closure for isolating the at least one purge chamber from the microwave tunnel, and at least one controller for controlling process parameters of the infeed module and the microwave tunnel, characterized in that: the system further comprises at least a second purge chamber in sealed communication with the at least one purge chamber and selectively isolated therefrom by a closure, whereby air in the second purge chamber is displaced by the reducing gas or another reducing gas to create a second reducing atmosphere in the second purge chamber having a lower concentration of oxygen than the reducing atmosphere in the first purge chamber. an infeed module for receiving material comprising organic materials and conveying the material into a reducing atmosphere, the infeed module comprising an infeed conveyor, for conveying the material through the infeed module, at least one purge chamber, a first closure for isolating the at least one purge chamber from an ambient atmosphere outside the system, a gas injection system in communication with the at least one purge chamber, for injecting a reducing gas to displace air from the at least one purge chamber to create a reducing atmosphere having a lowered concentration of oxygen in the at least one purge chamber, a microwave tunnel, the microwave tunnel being in sealed communication with the infeed module for isolating the microwave tunnel from the ambient atmosphere outside the system, the microwave tunnel comprising a microwave-impervious microwave chamber comprising a plurality of magnetrons for generating microwave radiation and at least one port for removal of process gas products, and a tunnel conveyor for receiving the material from the infeed module and transporting the material through the microwave chamber, at least a second closure for isolating the at least one purge chamber from the microwave tunnel, and at least one controller for controlling process parameters of the infeed module and the microwave tunnel,