Abstract: A method and apparatus for treating a commodity includes providing a sealed enclosure. A commodity is arranged in a plurality of layers spaced apart to provide ventilation areas between the layers. The commodity is further arranged in a plurality of rows having a space formed therebetween. A cover is positioned on a top surface and an exposed end surface of the rows or an exposed surface of an air handler to provide a seal. The air handler is positioned in communication with the space between the rows so as to move air along the space and through the ventilation areas, such that an even flow of air is achieved over the commodity. A catalytic heater/converter is provided for burning unburnt fuel and for depleting oxygen from the sealed enclosure during the heating of the commodity. A controller controls the air flowing through the ventilation areas and over the commodity.