Method of removing sulfur dioxide from waste gases

Abstract

Abstract A PROCESS FOR THE CONVERSION OF SOLIDS CONTAINING ALKALINE EARTH METAL AND SULFUR VALUES TO THE CORRESPONDING ALKALINE EARTH METAL CARBONATE AND AN ENRICHED HYDROGEN SULFIDE-CONTAINING GASEOUS PRODUCT WHICH INCLUDES A MULTISTAGE CONVERSION OF ALKALINE EARTH METAL SULFIDE TO THE INDICATED PRODUCTS. SOLIDS COMPRISING ALKALINE EARTH METAL SULFIDE ARE SLURRIED IN AN AQUEOUS MEDIUM AND THE RESULTING SLURRY IS CONTACTED WITH A GAS COMPRISING HYDROGEN SULFIDE TO PRODUCE AN AQUEOUS SOLUTION OF THE ALKALINE EARTH METAL HYDROSULFIDE, ANY WATER INSOLUBLE IMPURITIES ORIGINALLY ASSOCIATED WITH THE METAL SULFIDE REMAINING SUSPENDED IN THE AQUEOUS MEDIUM. THE AQUEOUS SOLUTION OF ALKALINE EARTH METAL HYDROSULFIDE, AFTER SEPARATION OF ANY SUCH IMPURITIES, IS THEN CONTACTED WITH CARBON DIOXIDE TO PRODUCE ALKALINE EARTH METAL CARBONATE AND AN ENRICHED HYDROGEN SULFIDE-CONTAINING GAS, A PORTION OF THE LATTER BEING USED TO FORM THE AQUEOUS SOLUTION OF ALKALINE EARTH METAL HYDROSULFIDE, AND THE REMAINING PORTION BEING CONVERTED TO ELEMENTAL EARTH OR SULFUR DIOXIDE. THE SOLIDS COMPRISING ALKALINE EARTH METAL SULFIDE MAY BE DERIVED BY REDUCTION OF ALKALINE EARTH METAL SULFATE INCLUDING NATIVE AND BYPRODUCT SUCH AS GYPSUM, AND ALKALINE EARTH METAL SULFATE PRODUCED BY TREATMENT OF SULFUR DIOXIDE-CONTAINING GASES OR SULFATE-CONTAINING WATERS WITH ALKALINE EARTH METAL CARBONATE OR OXIDE.

Inventors

• 👤 Ernesto Suriani
• 👤 Thomas H Milliken

Bibliographic Details