| 摘要 |
<p>A method and an apparatus for selectively removing, by liquid absorption, hydrogen sulphide from a gas containing both hydrogen sulphide and carbon dioxide, are disclosed. In a first stage of the method, the gas (3) is in a container (1) contacted, in at least one step, with a carbonate-containing alkaline solution whose pH is adjusted during the absorption by the addition of a hydroxide, such as sodium hydroxide. In a second stage of the method, the gas is combusted in a combustion device (32) for converting the hydrogen sulphide remaining in the gas to sulphur dioxide, which then is absorbed in an alkali-containing solution, such as a sodium hydroxide solution, in a wet cleaner (36). By combining the absorption of hydrogen sulphide in a carbonate-containing solution in a first stage, and the combustion of the remaining hydrogen sulphide to sulphur dioxide and the absorption of the formed sulphur dioxide in an alkaline solution in a second stage, one may attain a total hydrogen-sulphide separation of high selectivity, high degree of separation and good process economy.</p> |
