US3904734A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Decontamination of gas purification process effluent
Assignee: Babcock Woodall Duckham Ltd
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Filing: 1973-12-18
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Granted: 1975-09-09
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Expires: 1993-12-18
Abstract
Abstract Gas purification processes in which hydrogen sulphide (H2S) and/or hydrogen cyanide (HCN) are removed from a foul gas, e.g. coke-oven gas, by absorption in a circulating liquid reagent, for instance an alkaline anthraquinone disulphonic acid (ADA) salt solution or an alkaline polysulphide solution, produce an effluent containing noxious compounds with consequent disposal problems. The invention provides a method in which such an effluent is decomposed in a fluidised bed to products which may be recycled to the foul gas or to the process reagent as the case may be. Two such effluents of different types may be decomposed together in an integrated plant in which gaseous decomposition products are returned to the foul gas stream and any solids to one or the other or both of the process reagents as required.
Inventors
- 👤 Derek Vernon Gosden
- 👤 Anthony Roland Marshall
- 👤 David George Robson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 07:29
CPC Classifications
C; C10; C10K; C10K1/00; C10K1/08; C10K1/10; C10K1/12
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
127 words
IN A GAS PURIFICATION PROCESS IN WHICH AT LEAST ONE CONTAMINANT SELECTED FROM THE GROUP CONSISTING OF H2S AND HCN IS EXTRACTED FROM A FOUL GAS STREAM BY ABSORPTION IN A LIQUID REAGENT, H2S THEREBY BEING CONVERTED TO SULPHUR AND HCN TO THIOCYANATE AND THE REAGENT BEING SUBSEQUENTLY REGENERATED AND RECYCLED FOR ABSORPTION OF FURTHUR CONTAMINANT, THE METHOD OF DECONTAMINATING THE LIQUID REAGENT WHICH COM-PRISES: A. BLEEDING-OFF A SIDESTREAM OF SAID LIQUID REAGENT, B. REDUCING SAID SIDESTREAM IN ABED OF INHERT PARTICLES FLUIDIZED BY A REDUCING GAS AT A TEMPERATURE SO AS TO PRODUCE SUBSTANTIALLY GASEOUS AND SOLID PRODUCTS, C. RECYCLING THE GASEOUS PRODUCTS OF SUCH REDUCTION TO BE SAID FOUL GAS STREAM, AND D. RETURNING THE SOLID PRODUCTS OF SAID REDUCTION TO THE SAID LIQUID REAGENT.
Claim 2
Dependent Claim
127 words
IN A GAS PURIFICATION PROCESS IN WHICH AT LEAST ONE CONTAMINANT SELECTED FROM THE GROUP CONSISTING OF H2S AND HCN IS EXTRACTED FROM A FOUL GAS STREAM BY ABSORPTION IN A LIQUID REAGENT, H2S THEREBY BEING CONVERTED TO SULPHUR AND HCN TO THIOCYANATE AND THE REAGENT BEING SUBSEQUENTLY REGENERATED AND RECYCLED FOR ABSORPTION OF FURTHUR CONTAMINANT, THE METHOD OF DECONTAMINATING THE LIQUID REAGENT WHICH COM-PRISES: A. BLEEDING-OFF A SIDESTREAM OF SAID LIQUID REAGENT, B. REDUCING SAID SIDESTREAM IN ABED OF INHERT PARTICLES FLUIDIZED BY A REDUCING GAS AT A TEMPERATURE SO AS TO PRODUCE SUBSTANTIALLY GASEOUS AND SOLID PRODUCTS, C. RECYCLING THE GASEOUS PRODUCTS OF SUCH REDUCTION TO BE SAID FOUL GAS STREAM, AND D. RETURNING THE SOLID PRODUCTS OF SAID REDUCTION TO THE SAID LIQUID REAGENT.
Claim 3
Dependent Claim
22 words
The method of claim 1, in which said reduction step is effected at a temperature in the range 500*-800*C. at atmospheric pressure.
Claim 4
Dependent Claim
15 words
The method of claim 1, in which the fluidisation medium is a gas comprising hydrogen.
Claim 5
Dependent Claim
15 words
The method of claim 1, in which the fluidised bed particles comprise a synthetic rutile.
Claim 6
Dependent Claim
43 words
The method of claim 4, in which the liquid reagent sidestream contains salts giving solid reduction products which are deposited on the said particles, said particles being continually withdrawn and leached to extract soluble solids therefrom and then returned to the fluidized bed.
Claim 7
Dependent Claim
67 words
The method of claim 5, in which said withdrawn bed particles are leached with said liquid reagent sidestream to produce a slurry of leached particles and reagent and a separable liquid phase enriched in said soluble solids, said slurry being separated from said liquid phase and fed to the fluidized bed while said separated liquid phase is recycled to the liquid reagent of the gas purification process.
Claim 8
Dependent Claim
63 words
The method of claim 6, in which two gas purification stages are utilized, wherein a sidestream of the liquid reagent of the first gas purification sTage is used to leach said withdrawn particles and to form said slurry and a sidestream of the liquid reagent of the second gas purification stage is added to said slurry and introduced therewith to the fluidised bed.
Claim 9
Dependent Claim
59 words
The method of claim 6, in which two gas purification stages are utilized, wherein portions of withdrawn particles are leached with sidestreams of the liquid reagents of said individual gas purification stages to form individual slurry portions and associated liquid phases, said liquid phases portions being recycled to the respective liquid reagents from which the individual sidestreams are derived.
Claim 10
Dependent Claim
148 words
In a gas purification process in which at least one contaminant selected from the group consisting of H2S and HCN is extracted from a foul gas stream by absorption in a liquid reagent, H2S thereby being converted to sulphur and HCN to thiocyanate and the reagent being subsequently regenerated and recycled for absorption of further contaminant, the improvement which comprises decontaminating the liquid reagent by a. bleeding-off a sidestream of said liquid reagent; b. reducing said sidestream to substantially gaseous and solid products in a bed of inert particles fluidized by a reducing gas at a temperature range of 500* to 800*C. at atmospheric pressure, said reducing gas being selected from the group consisting of hydrogen and a hydrogen-containing gas; c. recycling the gaseous products of said reduction to the said foul gas stream; and d. returning the solid products of said reduction to the said liquid reagent.
Claim 11
Dependent Claim
148 words
In a gas purification process in which at least one contaminant selected from the group consisting of H2S and HCN is extracted from a foul gas stream by absorption in a liquid reagent, H2S thereby being converted to sulphur and HCN to thiocyanate and the reagent being subsequently regenerated and recycled for absorption of further contaminant, the improvement which comprises decontaminating the liquid reagent by a. bleeding-off a sidestream of said liquid reagent; b. reducing said sidestream to substantially gaseous and solid products in a bed of inert particles fluidized by a reducing gas at a temperature range of 500* to 800*C. at atmospheric pressure, said reducing gas being selected from the group consisting of hydrogen and a hydrogen-containing gas; c. recycling the gaseous products of said reduction to the said foul gas stream; and d. returning the solid products of said reduction to the said liquid reagent.
Claim 12
Dependent Claim
17 words
The process of claim 1, wherein the liquid reagent is an alkaline anthraquinone disulphonic acid salt solution.
Claim 13
Dependent Claim
14 words
The process of claim 1, wherein the liquid reagent is an alkaline polysulphide solution.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-08 | 1979-03-10 | 1979-09-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-08 | 1983-03-10 | 1983-09-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-08 | 1987-03-10 | 1987-09-09 | $7700.00 | Window Closed / Lapsed |