PROCESS FOR COMPLETELY OXIDIZING SULFUR FROM H 2 S PRESENT IN A GAS AND ITS APPLICATION TO TOTALLY RECOVERY AS SULFUR OF SULFUR COMPOUNDS CONTAINED IN SULFUR FACTORY WASTE GAS

摘要

An oxidation unit (2a) is used which comprises, in series, three catalytic stages (3a, 4a, 5a) each containing a catalyst for promoting the selective oxidation of H2S to sulphur up to a temperature theta s /= 150 DEG C. The gas to be processed (16) is fed through each of said stages and air (50, 53a, 55a) is injected into each stage. An H2S fraction of said gas is adiabatically oxidised to sulphur in each of the first two stages (3a, 4a) with an amount of air such that a temperature no higher than theta s is achieved at the outlet of said stages. All the H2S in the gas fed into the final stage (5a) is oxidised in a controlled excess of air at temperatures no higher than theta s. The method is useful for processing H2S-containing gases produced by the hydrogenation/hydrolysis of sulphur plant waste gases.