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US 4,526,773 AGranted
Scrubbing and oxidation of hydrogen sulfide with removal of dissolved oxygen from scrubbing solution before reuse
AssigneeLinde Aktiengesellschaft
InventorGunter Weber
Life of this patent
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Abstract
In a continuous process for the removal of H.sub.2 S from a gaseous mixture involving: (a) simultaneous absorption and oxidation of H.sub.2 S to form elemental sulfur; (b) regeneration of the oxidizing agent, e.g., vanadate, by treating the used scrubbing liquid with air; and (c) recycling the regenerated scrubbing liquid to the scrubbing step, to avoid the formation of sulfates and thiosulfates, the dissolved oxygen is substantially prevented from appearing in the scrubbing solution before reuse.
Claims21
In a process for the removal of hydrogen sulfide from a gaseous mixture comprising:
- (a) scrubbing said gaseous mixture with an aqueous alkaline scrubbing solution containing an oxidizing agent, whereby the sulfide of the hydrogen sulfide is oxidized principally to elementary sulfur, with the simultaneous reduction of the oxidizing agent to a lower valence state;
- (b) regenerating resultant scrubbing solution in a downstream oxidizer comprising introducing an oxygen-containing gas into the scrubbing solution to form dissolved oxygen which reoxidizes the reduced oxidizing agent;
- (c) removing elementary sulfur from the scrubbing medium;
- and
- (d) recycling resultant sulfur-diminished and reoxidized scrubbing medium to said scrubbing step (a);
- the improvement which comprises conducting step (b) so that the reduced oxidizing agent is oxidized to only 60-85% thereof, resulting in residual reduced oxidizing agent, the latter functioning as a scavenger for any oxygen present to substantially prevent the presence of residual dissolved oxygen in the scrubbing solution recycled to the scrubbing step (a).
3 more elements
Dependencies are inferred from the claim text.