US4976979A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the decaffeination of tea
Assignee: Evonik Operations GmbH
•
Filing: 1989-03-20
•
Granted: 1990-12-11
•
Expires: 2009-03-20
Abstract
Abstract The present invention provides a process for the decaffeination of tea containing 15 to 50% by weight of water with moist carbon dioxide at 255 to 350 bar at 50° to 80° C. in a pressure vessel, subsequent separation of the caffeine from the carbon dioxide with the help of an adsorbent and recycling the caffeine-free carbon dioxide over the already extracted tea, wherein the adsorbent is distributed in the material to be extracted in an amount of from 5 to 40% by weight, referred to the dry weight of the tea.
Inventors
- 👤 Hubertus Klima
- 👤 Erwin Schutz
- 👤 Heinz-Rudiger Vollbrecht
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:08
CPC Classifications
A; A23; A23F; A23F3/00; A23F3/36; A23F3/38; A23F3/385; A23F3/366; B; B01; B01D; B01D11/00; B01D11/02; B01D11/0215; B01D11/0219; B01D11/028; B01D11/0284
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
124 words
A process for the selective decaffeination of tea, comprising distributing in the tea, a charcoal adsorbing means operable to remove caffeine from solution in carbon dioxide; adjusting the moisture content of the tea to 15 to 50% by weight of water; extracting the tea containing 15 to 50% by weight of water in a single step with moist carbon dioxide at 255 to 350 bar and at 50° to 80° C. in a pressure vessel thereby to extract the caffeine into the carbon dioxide and remove the caffeine from the carbon dioxide into the adsorbent; and recycling the caffeine-free carbon dioxide over the already extracted tea and separating the carbon dioxide from the tea essentially without removing flavor, color or aroma from the tea.
Claim 2
Dependent Claim
124 words
A process for the selective decaffeination of tea, comprising distributing in the tea, a charcoal adsorbing means operable to remove caffeine from solution in carbon dioxide; adjusting the moisture content of the tea to 15 to 50% by weight of water; extracting the tea containing 15 to 50% by weight of water in a single step with moist carbon dioxide at 255 to 350 bar and at 50° to 80° C. in a pressure vessel thereby to extract the caffeine into the carbon dioxide and remove the caffeine from the carbon dioxide into the adsorbent; and recycling the caffeine-free carbon dioxide over the already extracted tea and separating the carbon dioxide from the tea essentially without removing flavor, color or aroma from the tea.
Claim 3
Dependent Claim
30 words
The process of claim 1, wherein the adsorbing means is active carbon used in an amount of 5 to 40% by weight referred to the dry weight of the tea.
Claim 4
Dependent Claim
22 words
The process of claim 1, wherein the adsorbing means is homogeneously mixed with the tea before being placed into the pressure vessel.
Claim 5
Dependent Claim
25 words
The process of claim 1, wherein the adsorbing means is distributed by filling the pressure vessel with alternating layers of the tea and adsorbing means.
Claim 6
Dependent Claim
31 words
The process of claim 1 further comprising passing the stream of carbon dioxide through a pure adsorbent packing and thereafter removing the carbon dioxide from the pressure vessel for further use.
Claim 7
Dependent Claim
22 words
The process of claim 1 wherein said adsorbing means is an adsorbent with a grain size of from 0.1 to 10 mm.
Claim 8
Dependent Claim
27 words
The process of claim 7 further comprising separating the adsorbent from the tea after the extraction by means of cyclone separation, air sifting, sieve classification or electrofiltration.
Claim 9
Dependent Claim
13 words
The process of claim 6 wherein the adsorbent is enveloped with gas-permeable material.
Claim 10
Dependent Claim
19 words
The process of claim 8, wherein the adsorbent is used filled into bags, sacks or tubes of textile material.
Claim 11
Dependent Claim
16 words
The process of claim 8, wherein the adsorbent is enveloped in porous clay or porous graphite.
Claim 12
Dependent Claim
20 words
The process of claim 1 wherein the carbon dioxide flows through the pressure vessel in the axial or radial direction.
Claim 13
Dependent Claim
16 words
The process of claim 1 wherein extraction is carried out for from 1 to 4 hours.
Claim 14
Dependent Claim
25 words
The process of claim 1 wherein 0.1 to 3 kg of carbon dioxide are used per gram of caffeine to be removed from the tea.
References Cited (Backward Citations)
US2198859A
Cited
FR2360260A1
Cited
US4247570A
Cited
US4411923A
Cited
FR2408607A1
Cited
US4364965A
Cited
EP0140061A2
Cited
DE3413869A1
Cited
EP0159724A2
Cited
DE3415844A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-12-10 | 1994-06-11 | 1994-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-10 | 1998-06-11 | 1998-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-10 | 2002-06-11 | 2002-12-11 | $7700.00 | Window Closed / Lapsed |