Dual temperature dual desulfurization
OwnerDonald C. Ericksoninventor
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Abstract
A fuel gas is desulfurized while hot by contact with a molten alkali salt. The salt is regenerated for further use by contact with a recirculating gas stream. The H.sub.2 S and COS picked up by the recirculating gas stream is scrubbed at low temperature in an aqueous alkaline salt scrub system such as hot potash. H.sub.2 S regenerated from the low temperature alkaline scrub system is subsequently converted to sulfur. By combining both high temperature and low temperature alkali scrubbing in a single dual temperature dual alkali (DTDA) process, the best advantages of both scrub techniques are retained whereas the serious disadvantages of molten salt scrubbing are eliminated.
Claims4
In a continuous process in which a high temperature reducing gas is scrubbed of H.sub.2 S by contact with at least one molten alkali salt scrubbing medium, which is regenerated for reuse, the improvement which comprises:
- a. regenerating the molten salt by contacting it with a recirculating gas stream comprised essentially of H.sub.2 O, CO.sub.2, H.sub.2, and CO, whereby H.sub.2 S is introduced into the recirculating gas stream;
- b. scrubbing the H.sub.2 S from the recirculating gas stream using an aqueous alkaline salt scrubbing medium;
- c. recycling the recirculating gas stream to further molten salt regeneration;
- d. adding a makeup gas consisting essentially of CO.sub.2 optionally admixed with H.sub.2 O to the recirculating gas stream.
Dependencies are inferred from the claim text.