US3846538A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for regenerating strong bases from solutions of their sulfides and simultaneously producing sulfur
Assignee: IFP Energies nouvelles
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Filing: 1972-09-19
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Granted: 1974-11-05
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Expires: 1992-09-19
Abstract
Abstract Process for regenerating a strong base from an aqueous solution of a sulfide thereof comprising (a) contacting said sulfide with an ammonium salt of a strong inorganic acid or an organic acid of low volatility, so as to obtain an aqueous solution of the resulting salt, at such a temperature that hydrogen sulfide and ammonia evolve, (b) contacting said hydrogen sulfide and ammonia with sulfurous anhydride for recovering sulfur and releasing ammonia and water in a gaseous state, (c) contacting said salt with an anionic ion exchange resin so as to release the strong base and to enrich the resin with acid, (d) periodically regenerating the resin with an aqueous solution of ammonia from stage (b) and (e) feeding back to stage (a) the product obtained when regenerating the resin, which consists of a solution of the ammonium salt of the acid.
Inventors
- 👤 P Renault
- 👤 C Dezael
- 👤 A Deschamps
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 05:03
CPC Classifications
C; C01; C01B; C01B17/00; C01B17/16; C01B17/167; C01C; C01C1/00; C01C1/02; C01C1/10; C01D; C01D1/00; C01D1/04
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
220 words
A PROCESS FOR REGENERATING A STRONG BASE FROM AN AQUEOUS SOLUTION OF A CORRESPONDING SULFIDE OF SAID STRONG BASE, WHEREIN (A) THE AQUEOUS SOLUTION OF SAID SULFIDE IS CONTACTED WITH AN AMMONIUM SALT OF A STRONG INORGANIC ACID OR AN ORGANIC ACID LESS VOLATILE THAN HYDROGEN SULFIDE, AT SUCH A TEMPERATURE THAT HYDROGEN SULFIDE AND AMMONIA EVOLVE, SO AS TO OBTAIN AN AQUEOUS SOLUTION OF THE SALT OF THE ACID AND THE STRONG BASE; (B) THE HYDROGEN SULFIDE AND THE AMMONIA OBTAINED IN THE STAGE (A) ARE CONTACTED WITH SULFUROUS ANHYDRIDE FOR RECOVERING SULFUR AND RELEASING, IN A GASEOUS STATE, AMMONIA AND WATER; (C) THE SOLUTION OF THE SALT OF THE ACID AND THE STRONG BASE PRODUCED IN THE STAGE (A) IS CONTACTED WITH AN ANIONIC ION EXCHANGE RESIN IN ORDER TO RELEASE THE STRONG BASE AND TO ENRICH THE RESIN WITH ACID; (C) THE CONTACT WITH THE RESIN IS PERIODICALLY INTERRUPTED AND THE LATTER IS TREATED WITH AN AQUEOUS SOLUTION OF AMMONIA ISSUING FROM STAGE (B), SO AS TO REGENERATE THE RESIN WHICH, AFTER REGENERATION, IS CONTACTED WITH THE SOLUTION OF THE SALT FORMED BY THE ACID AND THE STRONG BASE; AND (E) THE PRODUCT OBTAINED WHEN REGENERATING THE RESIN, WHICH CONSISTS OF AN AQUEOUS SOLUTION OF THE AMMONIUM SALT OF THE ACID, IS FED BACK TO STAGE (A).
Claim 2
Dependent Claim
220 words
A PROCESS FOR REGENERATING A STRONG BASE FROM AN AQUEOUS SOLUTION OF A CORRESPONDING SULFIDE OF SAID STRONG BASE, WHEREIN (A) THE AQUEOUS SOLUTION OF SAID SULFIDE IS CONTACTED WITH AN AMMONIUM SALT OF A STRONG INORGANIC ACID OR AN ORGANIC ACID LESS VOLATILE THAN HYDROGEN SULFIDE, AT SUCH A TEMPERATURE THAT HYDROGEN SULFIDE AND AMMONIA EVOLVE, SO AS TO OBTAIN AN AQUEOUS SOLUTION OF THE SALT OF THE ACID AND THE STRONG BASE; (B) THE HYDROGEN SULFIDE AND THE AMMONIA OBTAINED IN THE STAGE (A) ARE CONTACTED WITH SULFUROUS ANHYDRIDE FOR RECOVERING SULFUR AND RELEASING, IN A GASEOUS STATE, AMMONIA AND WATER; (C) THE SOLUTION OF THE SALT OF THE ACID AND THE STRONG BASE PRODUCED IN THE STAGE (A) IS CONTACTED WITH AN ANIONIC ION EXCHANGE RESIN IN ORDER TO RELEASE THE STRONG BASE AND TO ENRICH THE RESIN WITH ACID; (C) THE CONTACT WITH THE RESIN IS PERIODICALLY INTERRUPTED AND THE LATTER IS TREATED WITH AN AQUEOUS SOLUTION OF AMMONIA ISSUING FROM STAGE (B), SO AS TO REGENERATE THE RESIN WHICH, AFTER REGENERATION, IS CONTACTED WITH THE SOLUTION OF THE SALT FORMED BY THE ACID AND THE STRONG BASE; AND (E) THE PRODUCT OBTAINED WHEN REGENERATING THE RESIN, WHICH CONSISTS OF AN AQUEOUS SOLUTION OF THE AMMONIUM SALT OF THE ACID, IS FED BACK TO STAGE (A).
Claim 3
Dependent Claim
14 words
A process according to claim 1, wherein the sulfide is sodium or potassium sulfide.
Claim 4
Dependent Claim
28 words
A process according to claim 1 wherein the ammonium salt used for displacing the hydrogen sulfide from the sulfide solution is an ammonium salt of strong inorganic acid.
Claim 5
Dependent Claim
16 words
A process according to claim 3 wherein the ammonium salt is ammonium chloride or ammonium sulfate.
Claim 6
Dependent Claim
14 words
A process according to claim 4, wherein the sulfide is sodium or potassium sulfide.
Claim 7
Dependent Claim
40 words
A process according to claim 1, wherein the ammonium salt used for displacing the hydrogen sulfide from the strong base sulfide solution is a salt of an organic acid of 2-20 carbon atoms whose pK value is lower than 5.
Claim 8
Dependent Claim
30 words
A process according to claim 6, wherein the ammonium salt is selected from the group consisting of the ammonium salts of acetic acid, citric acid, benzoic acid and adipic acid.
Claim 9
Dependent Claim
29 words
A process according to claim 1, wherein the aqueous solution of said sulfide results from contacting a hydrogen sulfide containing gas with an aqueous solution of a strong base.
Claim 10
Dependent Claim
23 words
A process according to claim 8 wherein the aqueous solution of a strong base has a concentration of from 0.1 to 8 moles/liter.
Claim 11
Dependent Claim
22 words
A process according to claim 8 wherein the aqueous solution of a strong base has a concentration from 0.5 to 2 moles/liter.
Claim 12
Dependent Claim
21 words
A process according to claim 1, wherein the aqueous solution of ammonium salt has a concentration of 0.5 to 5 moles/liter.
Claim 13
Dependent Claim
36 words
A process according to claim 1, wherein the stage (b) is carried out in a liquid phase containing a heavy alcohol, a polyol, a mono- or polyalkylene glycol or an ether or ester of these compounds.
Claim 14
Dependent Claim
20 words
A process according to claim 1, wherein the aqueous ammonia solution has a concentration from 2 N up to saturation.
Claim 15
Dependent Claim
14 words
A process according to claim 5, wherein the anionic exchange resin is a polyamine.
Claim 16
Dependent Claim
18 words
A processs according to claim 14, wherein step (a) is conducted at a temperature of at least 90*C.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-04 | 1978-05-06 | 1978-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-04 | 1982-05-06 | 1982-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-04 | 1986-05-06 | 1986-11-05 | $7700.00 | Window Closed / Lapsed |