Sulfuric Acid (Single Absorption Process)

Abstract

All commercial sulphur sources containing more than 99.5 percent sulphur are suitable as raw materials. The sulphur is melted and burned with dried air to give a gas mixture containing 8 to 12 percent S02 by volume, the combustion temperature is held at about 800'C. After addition of more air, the S'2 is oxidised to S'3 over a vanadium catalyst. The S03 is absorbed in sulphuric acid of 98.3 percent H2S04 and converted with its water content into H2S04. Absorption and drying of the process air take place in packed towers where the gas are sprayed in counter-current with cooled concentrated sulphuric acid. The entire sulphuric acid plant operates with yields of more than 97.8 percent.