US3867509A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the purification of sulfur and nitrogen containing waste water and waste gas
Assignee: Evonik Operations GmbH
•
Filing: 1973-05-08
•
Granted: 1975-02-18
•
Expires: 1993-05-08
Abstract
Abstract Sulfur and nitrogen containing waste waters and waste gases are purified by treating with alkali or alkaline earth chlorites in acidic medium at a p H up to 6.
Inventors
- 👤 Friedhelm Geiger
- 👤 Theodor Lussling
- 👤 Wolfgang Igert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 09:14
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/72; C02F1/76; Y; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/916
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
102 words
A PROCESS FOR THE PURIFICATION OF (1) WASTE WATER OR (2) WASTE GAS CONTAINING AN OXIDIZABLE COMPOUND SELECTED FROM THE GROUP CONSISTING OF HYDROGEN SULFIDE, SULFUROUS ACID, A MERCAPTAN, A MERCAPTOAMINO CARBOXYLIC ACID, A THIOETHER, A DISULFIDE, A SULFOXIDE, A PHENOL, ALLYL ALCOHOL, TOLUENE, ANETHOL CINNAMYL ALCOHOL, CINNAMALDEHYDE, OLEIC ACID, GLYCERYL TRIOLE ATE, FURFURAL, INDOLE, B-METHYLINDOLE AND HYDROGEN CYANIDE COMPRISING TREATING THE WASTE WATER WITH ALKALI OR ALKALINE EARTH CHLORITE IN AN ACID MEDIUM AT A PH UP TO 6 OR PASSING THE WASTE GAS THROUGH AH AQUEOUS SOLUTION OF ALKALI OR ALKALINE EARTH CHLORITE AT A PH OF UP TO 6.
Claim 2
Dependent Claim
102 words
A PROCESS FOR THE PURIFICATION OF (1) WASTE WATER OR (2) WASTE GAS CONTAINING AN OXIDIZABLE COMPOUND SELECTED FROM THE GROUP CONSISTING OF HYDROGEN SULFIDE, SULFUROUS ACID, A MERCAPTAN, A MERCAPTOAMINO CARBOXYLIC ACID, A THIOETHER, A DISULFIDE, A SULFOXIDE, A PHENOL, ALLYL ALCOHOL, TOLUENE, ANETHOL CINNAMYL ALCOHOL, CINNAMALDEHYDE, OLEIC ACID, GLYCERYL TRIOLE ATE, FURFURAL, INDOLE, B-METHYLINDOLE AND HYDROGEN CYANIDE COMPRISING TREATING THE WASTE WATER WITH ALKALI OR ALKALINE EARTH CHLORITE IN AN ACID MEDIUM AT A PH UP TO 6 OR PASSING THE WASTE GAS THROUGH AH AQUEOUS SOLUTION OF ALKALI OR ALKALINE EARTH CHLORITE AT A PH OF UP TO 6.
Claim 3
Dependent Claim
11 words
A process according to claim 1 wherein waste water is purified.
Claim 4
Dependent Claim
18 words
A process according to claim 2, wherein the waste water is waste water from the manufacture of methionine.
Claim 5
Dependent Claim
19 words
A process according to claim 2 wherein the waste water is waste water from the manufacture of a mercaptan.
Claim 6
Dependent Claim
12 words
A process according to claim 4 wherein the mercaptan is methyl mercaptan.
Claim 7
Dependent Claim
19 words
A process according to claim 2 wherein the waste water is waste water from the manufacture of methyl mercapto-propionaldehyde.
Claim 8
Dependent Claim
18 words
A process according to claim 2 wherein the waste water is waste water from the manufacture of methylmercaptodichlorotriazine.
Claim 9
Dependent Claim
11 words
A process according to claim 1, wherein waste gas is purified.
Claim 10
Dependent Claim
29 words
A process according to claim 8 wherein the oxidizable sulfur compound is hydrogen sulfide, sulfurous acid, a mercaptan, a mercaptoamino carboxylic acid, a thioether, a disulfide or a sulfoxide.
Claim 11
Dependent Claim
18 words
A process according to claim 9, wherein the waste gas is waste gas from the manufacture of methionine.
Claim 12
Dependent Claim
28 words
A process according to claim 2 wherein the oxidizable compound is hydrogen sulfide, sulfurous acid, a mercaptan, a mercaptoamino carboxylic acid, a thioether, a disulfide or a sulfoxide.
Claim 13
Dependent Claim
17 words
A process according to claim 11 wherein aqueous HCl or H2SO4 is employed to establish the pH.
Claim 14
Dependent Claim
21 words
A process according to claim 1 wherein waste water is purified and the waste water withdrawn contains 5-100 mg/l of chlorite.
Claim 15
Dependent Claim
32 words
A process according to claim 1 wherein waste gas is purified by treating with a chlorite containing acidified chlorite containing wash liquor and the wash liquor withdrawn contains 5-100 mg/l of chlorite.
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) | 1978-02-17 | 1978-08-19 | 1979-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-17 | 1982-08-19 | 1983-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-17 | 1986-08-19 | 1987-02-18 | $7700.00 | Window Closed / Lapsed |