US4411923A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the extraction of caffeine from super-critical solutions
Assignee: Hag AG
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Filing: 1981-02-09
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Granted: 1983-10-25
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Expires: 2001-02-09
Abstract
Abstract A process for extracting caffeine from raw coffee, roast coffee, tea and the like. Super-critical carbon dioxide is used as extracting agent, and ion-exchangers are used to absorb the caffeine, and are subsequently regenerated by use of aqueous regenerating agents.
Inventors
- 👤 Peter Hubert
- 👤 Otto Vitzthum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:43
CPC Classifications
B; B01; B01D; B01D11/00; B01D11/02; B01D11/0203; A; A23; A23F; A23F3/00; A23F3/36; A23F3/366; A23F5/00; A23F5/20; A23F5/206; B01D11/0292
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
111 words
Process for extracting caffeine from caffeine-containing natural substances using super-critical carbon dioxide as extracting agent wherein caffeine and non-caffeine substances are removed from said natural substances by the extracting agent, including the steps of (a) selectively removing caffeine from the extracting agent with a polystyrene-based cation exchanger with sulfonic acid groups at a pressure between 100 to 300 bars; (b) adding from 5% to 30% water based on the total weight of the cation exchange resin to moisten the caffeine-filled resin and thereby avoid explosion of the resin particles during and after release of the CO 2 gas; and (c) regenerating said cation exchange resin by use of aqueous regenerating agents.
Claim 2
Dependent Claim
111 words
Process for extracting caffeine from caffeine-containing natural substances using super-critical carbon dioxide as extracting agent wherein caffeine and non-caffeine substances are removed from said natural substances by the extracting agent, including the steps of (a) selectively removing caffeine from the extracting agent with a polystyrene-based cation exchanger with sulfonic acid groups at a pressure between 100 to 300 bars; (b) adding from 5% to 30% water based on the total weight of the cation exchange resin to moisten the caffeine-filled resin and thereby avoid explosion of the resin particles during and after release of the CO 2 gas; and (c) regenerating said cation exchange resin by use of aqueous regenerating agents.
Claim 3
Dependent Claim
29 words
Process according to claim 1, wherein the caffeine adsorption in the CO 2 -system by the cation exchangers is effected at temperatures different from those used for the extraction.
Claim 4
Dependent Claim
21 words
Process according to claim 1, wherein the natural substances are selected from the group comprising raw coffee, roast coffee and tea.
Claim 5
Dependent Claim
25 words
Process according to claim 1, wherein the regeneration of the cation exchangers is effected with aqueous salt solutions at temperatures between 20° and 100° C.
Claim 6
Dependent Claim
25 words
Process according to claim 1, wherein the regeneration of the cation exchangers is effected with aqueous mineral acids at temperatures between 20° and 100° C.
Claim 7
Dependent Claim
17 words
Process according to claim 5, wherein the regeneration is effected at temperatures between 80° and 90° C.
Claim 8
Dependent Claim
39 words
Process according to claim 1, wherein the regeneration of the cation exchangers is carried out by displacing the caffeine by (a) aqueous alkali metal or ammonia solutions; and (b) subsequent conversion of the exchangers into the H + form.
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) | 1986-10-24 | 1987-04-25 | 1987-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-24 | 1991-04-25 | 1991-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-24 | 1995-04-25 | 1995-10-25 | $7700.00 | Window Closed / Lapsed |