Abstract: A material containing combustible components is burned or gasified in a circulating fluidized bed comprising a turbulence chamber, a solids separator connected to the upper area of the turbulence chamber, a return line leading from the solids separator to the turbulence chamber and a cooling device for the indirect cooling of solids arriving from the solids separator. The cooling device comprises several fluidized beds through which the solids pass one after the other. The first fluidized bed, into which the hot solids arriving from the solids separator are introduced first, is situated in a dechlorinating chamber.