Method of working up cellulose waste liquor containing sodium and sulfur

Claim 1

A METHOD OF TREATING CELLULOSE WASTE LIQUORS CONTAINING SODIUM AND SULFUR COMPOUNDS FOR THE RECOVERY OF CHEMICAL COMPONENTS OF SAID LIQUORS, SAID METHOD COMPRISING: (1) THERMALLY DECOMPOSING THE LIQUOR BY DIRECTLY CONTACTING THE SAME IN A REACTION ZONE WITH A PREHEATED REDUCING GAS FLOWING CONCURRENTLY THEREWITH THROUGH SAID ZONE; (2) SEPARATING FROM ONE ANOTHER THE SOLID AND GASEOUS REACTION PRODUCTS OF SAID THERMAL DECOMPOSITION; (3) REMOVING SULFUR COMPONENTS FROM SAID GASEOUS REACTION PRODUCTS; (4) HEATING ONE PORTION OF THE DESULFURIZED GASEOUS REACTION PRODUCTS BY INDIRECT CONTACT THEREOF WITH HOT COMBUSTION GASES, SAID COMBUSTION GASES COMPRISING ANOTHER PORTION OF SAID DESULFURIZED GASEOUS REACTION PRODUCTS; (5) RETURNING SAID FIRST-NAMED PORTION OF SAID INDIRECTLY HEATED DESULFURIZED GASEOUS REACTION PRODUCTS TO SAID REACTION ZONE TO SERVE AS PREHEATED REDUCING GAS FOR SAID THERMAL DECOMPOSITION OF THE LIQUOR IN SAID REACTION ZONE; (6) TREATING THE HYDROGEN SULFIDE-CONTAINING GAS COMPONENT OF SAID GASEOUS REACTION PRODUCT TO FORM SULFUR DIOXIDE BY COMBUSTION OF SAID COMPONENT WITH AIR; (7) RECOVERING SODIUM CARBONATE FROM SAID SOLID REACTION PRODUCTS; AND (8) FORMING SODIUM SULFITE SOLUTION BY REACTING SAID SULFUR DIOXIDE WITH SAID SODIUM CARBONATE.

Claim 2

A METHOD OF TREATING CELLULOSE WASTE LIQUORS CONTAINING SODIUM AND SULFUR COMPOUNDS FOR THE RECOVERY OF CHEMICAL COMPONENTS OF SAID LIQUORS, SAID METHOD COMPRISING: (1) THERMALLY DECOMPOSING THE LIQUOR BY DIRECTLY CONTACTING THE SAME IN A REACTION ZONE WITH A PREHEATED REDUCING GAS FLOWING CONCURRENTLY THEREWITH THROUGH SAID ZONE; (2) SEPARATING FROM ONE ANOTHER THE SOLID AND GASEOUS REACTION PRODUCTS OF SAID THERMAL DECOMPOSITION; (3) REMOVING SULFUR COMPONENTS FROM SAID GASEOUS REACTION PRODUCTS; (4) HEATING ONE PORTION OF THE DESULFURIZED GASEOUS REACTION PRODUCTS BY INDIRECT CONTACT THEREOF WITH HOT COMBUSTION GASES, SAID COMBUSTION GASES COMPRISING ANOTHER PORTION OF SAID DESULFURIZED GASEOUS REACTION PRODUCTS; (5) RETURNING SAID FIRST-NAMED PORTION OF SAID INDIRECTLY HEATED DESULFURIZED GASEOUS REACTION PRODUCTS TO SAID REACTION ZONE TO SERVE AS PREHEATED REDUCING GAS FOR SAID THERMAL DECOMPOSITION OF THE LIQUOR IN SAID REACTION ZONE; (6) TREATING THE HYDROGEN SULFIDE-CONTAINING GAS COMPONENT OF SAID GASEOUS REACTION PRODUCT TO FORM SULFUR DIOXIDE BY COMBUSTION OF SAID COMPONENT WITH AIR; (7) RECOVERING SODIUM CARBONATE FROM SAID SOLID REACTION PRODUCTS; AND (8) FORMING SODIUM SULFITE SOLUTION BY REACTING SAID SULFUR DIOXIDE WITH SAID SODIUM CARBONATE.