| 摘要 |
<p>PURPOSE: To provide a method for tail gas treatment, as a closed system entirely free from secondary pollution problems such as exhaust gas and effluents from the sulfur recovery unit, having such advantages as low equipment and installa tion cost and also low in operational cost such as for chemicals. CONSTITUTION: A hydrogen sulfide-contg. gas is treated with an absorbing solution regenerating-type absorption device and elementary sulfur is recovered by Claus reaction using the hydrogen sulfide as feedstock obtained by regenerating the absorbing solution. In this sulfur recovery unit, the temperature of a tail gas discharged from the sulfur recovery unit is raised to a specified level followed by injecting hydrogen or a hydrogen-contg. gas into the tail gas, and the resultant mixed gas is passed through a hydrogenation catalyst to convert the sulfur compounds in the tail gas into hydrogen sulfide, which is then cooled to a specified temperature and circulatingly fed to the above absorbing solution regenerating-type absorption device.</p> |
