Process for pyrolyzing a solid or liquid hydrocarbonaceous fuel in a fluidized bed

Abstract

Abstract A SOLID OR LIQUID HYDROCARBONACEOUS FUEL, SUCH AS BITUMINOUS COAL OR RESIDUAL OIL, IS CHARGED TO A LOWER ZONE OF A FLUIDIZED BED, THIS ZONE COMPRISING COKE PELLETS, WHEREIN THE FUEL IS CARBONIZED OR CRACKED (I.E. PYROLYZED) TO FORM GASEOUS PRODUCTS AND A FRESH COKE ACCRETING UPON THE PELLETS. THE GASEOUS PRODUCTS FLUIDIZE A SUPERPOSED, CONTIGUOUS, UPPER ZONE OF THE FLUIDIZED BED, COMPRISING A SOLID OF SMALLER SIZE AND BEING FLUIDIZED AT LOWER VELOCITY. THE VELOCITY OF THE LOWER ZONE IS SUFFICIENT TO PREVENT THE SMALLER SOLID FROM PENETRATING DEEPLY INTO THE ZONE. HEAT IS SUPPLIED TO THE LOWER ZONE BY HEAT CONDUCTION FROM THE UPPER ZONE. THE HEAT IS EITHER GENERATED WITHIN THE UPPER ZONE (E.G., BY COMBUSTION OR OTHER CHEMICAL REACTION OR BY SUPPLY OF A HOT SOLID TO THE UPPER ZONE AND WITHDRAWAL OF SOLID THEREFROM) OR SUPPLIED THERETO BY INDIRECT HEAT EXCHANGE FROM A HEATING MEDIUM. ALTERNATIVELY, IF THE FUEL CARBONIZATION OR CRACKING IS CONDUCTED IN AN ATMOSPHERE OR HYDROGEN AT A SURRICIENTLY HIGH PARTIAL PRESSURE, SO THAT THE REACTION OF THE FUEL IS EXOTHERMIC, HEAT IS WITHDRAWN FROM THE LOWER ZONE BY HEAT CONDUCTION TO THE UPPER ZONE AND THE HEAT IS REMOVED FROM THE UPPER ZONE, E.G., BY INDIRECT HEAT EXCHANGE TO A COOLING MEDIUM.

Inventors

• 👤 Arthur M Squires

Bibliographic Details