Abstract: A method and apparatus for the removal and recovery of volatile or evaporable substances from materials containing them. In other embodiments, the invention is readily applicable for the simultaneous incineration and concentration of such materials, particularly spent water-diluted effluents from industries and municipalities as well as for the generation of electric power from various thermal fuels, particularly power gas produced from coal or oil. In further embodiments, the reclamation of oil, from oil sands and shales, is effected as well as the cyclic pulping of cellulosic materials with cyclic recovery of heat and chemicals.