Production of pure carbon dioxide

Claim 1

A PROCESS FOR PREPARING PURE CO2 SUBSTANTIALLY FREE OF NON-CONDENSIBLE GASES WHICH COMPRISES CONTACTING CARBONACEOUS MATERIAL IN A REACTION ZONE WITH SOLID FINELY-DIVIDED HIGHER METAL OXIDE SELECTED FROM THE GROUP CONISTING OF FERRIC OXIDE, VANADIUM PENTOXIDE AND STANNIC OXIDE, MAINTAINING THE SOLIDS CONTENT IN THE REACTION ZONE IN A FLUIDIZED STATE BY MEANS OF INJECTED CO2 GAS AND AT A TEMPERATURE OF 500* C. TO 1200* C. WHEREBY THE CARBONACEOUS MATERIAL IS OXIDIZED TO CO2 AND THE METAL OXIDE REDUCED TO A LOWER OXIDE, REMOVING SUBSTANTIALLY PURE CO2 FROM AN UPPER PART OF THE REACTION ZONE, REMOVING FROM THE REACTION ZONE A STREAM OF SOLID HIGHER AND LOWER METAL OXIDES CONTAINING AT LEAST 10 WEIGHT PER CENT OF THE HIGHER OXIDE, INTRODUCING THE WITHDRAWN STREAM INTO A SEPARATE OXIDATION ZONE WHEREIN THE LOWER OXIDE IS REOXIDIZED TO THE HIGHER OXIDE BY MEANS OF A FREE-OXYGEN-CONTAINING GAS AND THE EXOTHERMIC HEAT OF REACTION IMPARTED TO THE OXIDE, WITHDRAWING A STREAM OF HOT REOXIDIZED HIGHER METAL OXIDE FROM THE OXIDATION ZONE, PURGING THE HOT HIGHER METAL OXIDE OF NONCONDENSIBLE GASES BY MEANS OF CO2 GAS INJECTED INTO THE WITHDRAWN STREAM, SEPARATING THE PURGED NON-CONDENSIBLE GASES FROM THE HOT OXIDE, AND RETURNING HOT PURGED HIGHER METAL OXIDE FLUIDIZED IN CO2 TO THE REACTION ZONE.