Patent US4705637A successfully refreshed from Google Patents.
US4705637A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for reducing the wash water requirement of weakly basic anion exchangers
Assignee: Bayer AG
•
Filing: 1985-05-31
•
Granted: 1987-11-10
•
Expires: 2005-05-31
Abstract
Abstract The invention relate to a process for reducing the wash water required by weakly basic anion exchangers containing primary and/or secondary amino groups when fed with water containing carbon dioxide; in accordance with the process the exhausted, weakly basic anion exchangers are treated with dilute aqueous mineral acids before being regenerated.
Inventors
- 👤 Harold Heller
- 👤 Peter M. Lange
- 👤 Friedrich Martinola
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:10
CPC Classifications
B; B01; B01J; B01J49/00; B01J49/05; B01J49/07; B01J41/00; B01J41/04; B01J41/07
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
101 words
In a process which comprises completely loading a weakly basic anion exchanger containing primary and/or secondary amino groups with water containing carbon dioxide to thereby produce an exhausted weakly basic anion exchanger, regenerating the anion exchanger, washing the anion exchanger with water, and repeating the loading step, the improvement which comprises treating the exhausted weakly basic anion exchanger with a dilute aqueous mineral acid before it is regenerated, at least 0.25 equivalents of the mineral acid being used per equivalent of effective capacity of the weakly basic anion exchanger, whereby the amount of wash water required to remove regenerant is reduced.
Claim 2
Dependent Claim
101 words
In a process which comprises completely loading a weakly basic anion exchanger containing primary and/or secondary amino groups with water containing carbon dioxide to thereby produce an exhausted weakly basic anion exchanger, regenerating the anion exchanger, washing the anion exchanger with water, and repeating the loading step, the improvement which comprises treating the exhausted weakly basic anion exchanger with a dilute aqueous mineral acid before it is regenerated, at least 0.25 equivalents of the mineral acid being used per equivalent of effective capacity of the weakly basic anion exchanger, whereby the amount of wash water required to remove regenerant is reduced.
Claim 3
Dependent Claim
26 words
The process of claim 1, wherein the dilute aqueous mineral acid used is dilute aqueous hydrochloric acid, dilute aqueous nitric acid or dilute aqueous sulphuric acid.
Claim 4
Dependent Claim
23 words
The process of claim 1, wherein the concentration of the mineral acid in the dilute aqueous solution is 0.5 to 10% by weight.
Claim 5
Dependent Claim
36 words
The process of claim 1, wherein the mineral acid is employed in an amount such that 0.35 to 1.0 equivalents of mineral acid are used per equivalent of effective capacity of the weakly basic anion exchanger.
Claim 6
Dependent Claim
25 words
Process according to claim 1, characterised in that regeneration agent effluents, containing mineral acid, from cation exchangers are used as the dilute aqueous mineral acid.
References Cited (Backward Citations)
DE759180C
Cited
US2354172A
Cited
DE1063986B
Cited
DE1767584A1
Cited
FR2055000A5
Cited
US3887391A
Cited
US3982956A
Cited
US4247340A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-11-09 | 1991-05-11 | 1991-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-11-09 | 1995-05-11 | 1995-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-11-09 | 1999-05-11 | 1999-11-10 | $7700.00 | Window Closed / Lapsed |