Method of producing fuel gas and process heat fron carbonaceous materials

A method of generating a fuel gas and process heat from a carbonaceous material which comprises:

• (a) reacting said carbonaceous material with oxygen-containing gases in the presence of steam in a circulating fluidized bed of a fluidized bed reactor at a temperature of 800.degree. C. to 1100.degree. C. in a first fluidized bed stage in which solids are entrained by gases from the fluidized bed, separating the entrained solids from the gas phase and recycling at least a portion of the separated solids to the fluidized bed to react 40 to 80% of the carbon contained in said material and produce a fuel gas therefrom contained in said gas phase;
• (b) contacting thereafter said gas phase at a temperature of 800.degree. C. to 1000.degree. C. with particles of a sulfur-trapping solid which are fluidized in said gas phase thereby removing sulfur therefrom;
• (c) recovering sulfur-trapping particles from the gas phase following step (b);
• (d) cooling the gas phase following the recovery of the sulfur-trapping particles therefrom and subjecting the cooled gas phase to at least one dust collection step to obtain said fuel gas and collect dust from the cooled gas phase;
• and
• (e) feeding solids withdrawn from said first circulating fluidized bed stage, the dust collected in step (d), the particles recovered in step (c), and aqueous condensate, to a second circulating fluidized bed stage and burning combustible constituents therein with an oxygen excess of 5 to 40% to produce a waste gas which is discharged to the atmosphere after process heat recovery.