Treating a water stream containing a water-soluble sulfite compound

Abstract

Abstract A WATER STREAM CONTAINING A WATER-SOLUBLE SULFITE COMPOUND IS TREATED IN ORDER TO REDUCE ITS TOTAL SULFUR CONTENT WHILE MINIMIZING THE FORMATION OF SULFATE BY-PRODUCTS BY THE STEPS OF: (A) CONVERTING THE SULFITE COMPOUND CONTAINED IN THE WATER STREAM TO THE CORRESPONDING THIOSULFATE COMPOUND; (B) REACTING THE RESULTING THIOSULFATE COMPOUND WITH CARBON MONOXIDE AT REDUCTION CONDITIONS SELECTED TO PRODUCE THE CORRESPONDING SULFIDE COMPOUND; AND THEREAFTER (C) STRIPPING HYDROGEN SULFIDE FROM THE EFFLUENT STREAM FROM STEP (B) TO FORM A SUBSTANTIALLY SULFATEFREE TREATED WATER STREAM WHICH IS SUBSTANTIALLY REDUCED IN TOTAL SULFUR CONTENT RELATIVE TO THE INPUT WATER STREAM. PRINCIPAL UTILITY OF THIS TREATMENT PROCEDURE IS ASSOCIATED WITH THE REGENERATION OF A SULFITE-CONTAINING ABSORBENT STREAM WHICH IS COMMONLY PRODUCED BY CONTACTING A FLUE GAS STREAM CONTAINING SULFUR DIOXIDE WITH A SUITABLE AQUEOUS ABSORBENT STREAM CONTAINING AN ALKALINE REAGENT. T HE TREATED WATER STREAM PRODUCED BY THE PRESENT METHOD CAN THEN BE REUSED IN THE ABSORPTION PROCESS OR DISCHARGED INTO A SUITABLE SEWER WITHOUT CAUSING POLLUTION PROBLEMS. KEY FEATURES OF THIS METHOD INVOLVES THE SELECTIVE CONVERSION OF THE SULFITE COMPOUND TO THE CORRESPONDING THIOSULFATE COMPOUND, THE SUBSEQUENT REDUCTION OF THE THIOSULFATE COMPOUND TO THE CORRESPONDING SULFIDE COMPOUND IN A HIGHLY EFFICIENT, ECONOMIC AND SELECTIVE MANNER, AND THE MINIMIZATION OF UNDESIRED SULFATE BY-PRODUCTS DURING BOTH OF THESE CONVERSION STEPS.

Inventors

• 👤 Peter Urban

Bibliographic Details