Abstract: The invention provides a practical and efficient method and apparatus for thermally processing organic based raw materials of either primary or secondary (recycled) origin, in order to extract volatile organic vapors and to selectively produce either condensable hydrocarbon gases or, more preferably, non-condensable synthesis gases that are rich in hydrogen and carbon monoxide for use as a raw material in chemical processes, or as a fuel. In particular, the invention provides a single rotary reactor having two contiguous hearth reaction areas, i.e., a drying and volatizing area and a reformation area, the areas being separated from each other by a bed-retaining refractory weir. The weir has an aperture for fluidly connecting the two hearth reaction areas of the single reactor.