| 摘要 |
1,211,033. Removing SO 2 from waste gases. ONTARIO RESEARCH FOUNDATION. 10 Jan., 1969 [11 Jan., 1968], No. 1741/68. Heading C1A. Sulphur dioxide containing effluent gas is contacted with a reducing gas comprising H 2 S in the presence of a catalyst at a temperature of 50- 150‹ C. whereby the SO 2 is at least partially reduced to sulphur in accordance with the equation: and the sulphur is deposited on the catalyst, and removing the sulphur from the catalyst at least partially by reaction with carbon monoxide at a temperature of from 250-500‹ C. in order to provide regenerated, substantially sulphur free catalyst. The reaction with carbon monoxide preferably occurs at 300-450‹ C. The carbonyl sulphide produced may in turn be hydrolysed to CO 2 and H 2 S which is recycled, further H 2 S being produced if a mixture of CO and H 2 is used for removing the sulphur, steam (removing the necessity for subsequent hydrolysis) and an inert gas, such as N 2 , may also be present. Sufficient H 2 S is used in order to react with all the SO 2 , sufficient CO with or without H 2 is used to react with 2/3 of the sulphur produced, the rest being removed as sulphur vapour in the COS and subsequently removed; sufficient steam is used to hydrolyse all the COS produced. A continuous process for the removal of the catalyst from the sulphur depositing zone to the sulphur removing zone and: thereafter recycling the catalyst, is described. Catalysts disclosed for the sulphur producing stage are Pd, Pt, Rh, promoted iron oxide but preferably activated alumina or bauxite is used. This stage may be broken up into 2 parts: (a) reaction with H 2 S at 250-400‹ C. (b) completion of the reaction at 50-150‹ C. Some CS 2 may be produced especially if hydrocarbons are present in the CO or H 2 . This need not be hydrolysed since CS 2 will reduce SO 2 to S if recycled. |
