Two stage fluid bed regeneration of spent carbon

Abstract

Method and apparatus are disclosed for regenerating wet spent carbon containing volatile impurities wherein the wet spent carbon is dried in a drying zone utilizing incinerated reactivation zone gaseous effluent. The reactivation zone gaseous effluent is derived by reactivating dried spent carbon in a reactivation zone at pyrolysis conditions to remove volatile components from the adsorbent. Removal is effected utilizing combustion gases. The reactivation zone gaseous effluent is comprised of the combustion gases, the vaporized volatile impurities, and, where steam is employed in the reactivation zone to remove fixed carbon, substantial quantities of carbon monoxide and hydrogen. By interposing the incineration zone between the drying and reactivation zone, efficiency of the overall process is maximized. The combustible components of the combustion gases, the volatile impurities and the carbon monoxide and hydrogen, produced by removal of fixed carbon with steam, are burned in such a manner that the heat of combustion is used for drying the incoming wet spent carbon and for maintaining pyrolysis conditions required for reactivation. The effluent gases may be discharged directly into the atmosphere without further incineration.