US5397475A
Expired / Lapsed
US
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Purification of hydrogen peroxide
Assignee: Solvay Interox Ltd
•
Filing: 1991-10-02
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Granted: 1995-03-14
•
Expires: 2011-10-02
Abstract
Abstract Purification of aqueous hydrogen peroxide solutions using conventional ion-exchange techniques can result in the hydrogen peroxide decomposing explosively. Much safer processes are obtained by restricting the contact between the resin bed and the hydrogen peroxide solution to a very short contact time, by employing a treatment chamber that is vented to the atmosphere and also by slurrying the resin bed. The bed is conveniently retained on a mesh that acts as a filter (13) preferably conical having an aperture (17) at its apex through which is introduced a small fraction of the solution countercurrent (10) to the main solution flow (9) in order to slurry the bed (19). The solution can be recycled through the same bed or a plurality of beds. Very high purification can be achieved and combined with improved safety of operation.
Inventors
- 👤 Malcolm H. Millar
- 👤 Francis R. F. Hardy
- 👤 Gareth W. Morris
- 👤 John R. Crampton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:38
CPC Classifications
C; C01; C01B; C01B15/00; C01B15/01; C01B15/013; C01B15/0135; B; B01; B01J; B01J47/00; B01J47/10; B01J8/00; B01J8/18; B01J8/20
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
92 words
In a process for purifying an aqueous metal ion-containing hydrogen peroxide solution which comprises contacting said solution with an ion exchange resin in acid form until at least a fraction of the metal ions have been exchanged for hydrogen ions, and thereafter separating the ion exchange resin and solution, the improvement wherein the resin is employed in the form of a shallow slurried bed of ion exchange particles and wherein said contacting is effected by passing said solution through said bed at a rate of at least 200 bed volumes per hour.
Claim 2
Dependent Claim
92 words
In a process for purifying an aqueous metal ion-containing hydrogen peroxide solution which comprises contacting said solution with an ion exchange resin in acid form until at least a fraction of the metal ions have been exchanged for hydrogen ions, and thereafter separating the ion exchange resin and solution, the improvement wherein the resin is employed in the form of a shallow slurried bed of ion exchange particles and wherein said contacting is effected by passing said solution through said bed at a rate of at least 200 bed volumes per hour.
Claim 3
Dependent Claim
25 words
A process according to claim 1 wherein the solution is passed through the bed at a rate of at least 500 bed volumes per hour.
Claim 4
Dependent Claim
16 words
A process according to claim 1 wherein the solution flows through the resin bed under gravity.
Claim 5
Dependent Claim
27 words
A process according to claim 1 wherein the linear ratio of head of solution to bed depth is selected within the range of from 5:1 to 50:1.
Claim 6
Dependent Claim
27 words
A process according to claim 1 wherein the total contact time between the resin and the solution is within the range of from 5 to 75 seconds.
Claim 7
Dependent Claim
22 words
A process according to claim 1 wherein the solution is passed through the resin and/or a different resin a plurality of times.
Claim 8
Dependent Claim
23 words
A process according to claim 6 further comprising the step of changing said bed after each passage of said solution through said bed.
Claim 9
Dependent Claim
20 words
A process according to claim 6 wherein said solution is passed through said resin bed from 5 to 12 times.
Claim 10
Dependent Claim
25 words
A process according to claim 1 wherein the resin particles are fluidised by an upward stream of at least part of the hydrogen peroxide solution.
Claim 11
Dependent Claim
36 words
A process according to claim 9 wherein a fluidised bed of said particles is created by an upward stream of at least part of the hydrogen peroxide solution concentrated at a central zone of the bed.
Claim 12
Dependent Claim
15 words
A process according to claim 10 wherein the bed is retained within an inclined sidewall.
Claim 13
Dependent Claim
19 words
A process according to claim 11 wherein the sidewall comprises a mesh filter that defines a downward pointing cone.
Claim 14
Dependent Claim
21 words
A process according to claim 1 wherein the resin employed comprises a cross linked polystyrene resin bearing pendant sulphonic acid groups.
Claim 15
Dependent Claim
149 words
Apparatus for purifying an aqueous metal ion-containing hydrogen peroxide solution comprising: a vessel containing a bed of ion exchange resin particles in acid form; a reservoir of metal ion-containing aqueous hydrogen peroxide solution; means for passing a fluid upwardly through said resin bed to slurry the ion exchange resin particles in the form of a shallow slurried bed of said particles; means for passing hydrogen peroxide solution from said reservoir through said shallow slurried bed of ion exchange resin particles at a rate of at least 200 bed volumes per hour to effect contact of said hydrogen peroxide solution with said ion exchange particles in said shallow slurried bed to exchange at least a fraction of the metal ions with hydrogen ions; and outlet means for the passage of purified hydrogen peroxide solution from said vessel after the solution has passed through said shallow slurried ion exchange resin bed.
Claim 16
Dependent Claim
149 words
Apparatus for purifying an aqueous metal ion-containing hydrogen peroxide solution comprising: a vessel containing a bed of ion exchange resin particles in acid form; a reservoir of metal ion-containing aqueous hydrogen peroxide solution; means for passing a fluid upwardly through said resin bed to slurry the ion exchange resin particles in the form of a shallow slurried bed of said particles; means for passing hydrogen peroxide solution from said reservoir through said shallow slurried bed of ion exchange resin particles at a rate of at least 200 bed volumes per hour to effect contact of said hydrogen peroxide solution with said ion exchange particles in said shallow slurried bed to exchange at least a fraction of the metal ions with hydrogen ions; and outlet means for the passage of purified hydrogen peroxide solution from said vessel after the solution has passed through said shallow slurried ion exchange resin bed.
Claim 17
Dependent Claim
51 words
Apparatus according to claim 14 further comprising means for maintaining a body of said hydrogen peroxide solution above said slurried resin bed, the head of said body of said solution being sufficient to enable the solution to pass downwardly through said shallow slurried resin bed solely under the influence of gravity.
Claim 18
Dependent Claim
18 words
Apparatus according to claim 14 wherein said vessel comprises an inclined filter surface sidewall retaining said resin bed.
Claim 19
Dependent Claim
12 words
Apparatus according to claim 16 wherein the sidewall forms an inverted cone.
Claim 20
Dependent Claim
18 words
Apparatus according to claim 17 wherein said inverted cone has a cone angle of from 50° to 125°.
Claim 21
Dependent Claim
32 words
Apparatus according to claim 16 wherein the sidewall has an aperture at or adjacent to the base of the incline, said aperture being an inlet for upward introduction of the slurrying fluid.
Claim 22
Dependent Claim
26 words
Apparatus according to claim 14 wherein said fluid passing means comprises means for passing aqueous hydrogen peroxide solution from said reservoir upwardly through said resin bed.
Claim 23
Dependent Claim
18 words
Apparatus according to claim 14 further comprising closeable outlet means for discharging said resin particles from said vessel.
Claim 24
Dependent Claim
23 words
Apparatus according to claim 14 further comprising means for conveying the purified aqueous hydrogen peroxide solution from said outlet means to said reservoir.
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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) | 1998-03-13 | 1998-09-12 | 1999-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-03-13 | 2002-09-12 | 2003-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-03-13 | 2006-09-12 | 2007-03-14 | $7700.00 | Window Closed / Lapsed |