| 摘要 |
The present invention provides a process for purifying a sour gas stream containing hydrogen sulfide by (a) absorbing hydrogen sulfide from a sour gas (1) by contacting the gas with a hydrogen sulfide absorbent (3) in an absorber (101) to obtain a hydrogen sulfide-rich absorbent (5); (b) stripping hydrogen sulfide from the hydrogen sulfide-rich absorbent (5) to obtain a hydrogen sulfide-rich gas (8); (c) feeding the hydrogen sulfide-rich gas (8) together with sulfur dioxide-rich gas (9), so that the hydrogen sulfide is in stoichiometric excess, into a reactor column (108) in the presence of a solvent and catalyst (10) that catalyzes their reaction to form liquid sulfur and water vapor; (d) recovering the liquid sulfur from the reactor column; (e) recovering a hydrogen sulfide-rich off-gas from the reactor column; and (f) recovering hydrogen sulfide (2) from the hydrogen sulfide-rich off-gas and recycling the hydrogen sulfide thus recovered to the reactor of step (c). Preferably, the absorber column used in step (f) is part of the same absorber column that is used for step (a). Alternatively, the absorber of step (f) may be a second absorber, different from that of step (a), in which case a second hydrogen sulfide-rich gas is recovered from the second absorber, and is fed to the reactor, preferably as a combined stream with the hydrogen sulfide-rich gas from step (b). Preferably, the hydrogen sulfide-rich off-gas from the reactor column is cooled (112), dewatered (113) and compressed (116) while being recycled to the hydrogen sulfide absorber.
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