Patent
Purification of hydrogen peroxide
| العنوان: | Purification of hydrogen peroxide |
|---|---|
| Patent Number: | 5,397,475 |
| تاريخ النشر: | March 14, 1995 |
| Appl. No: | 08/030,487 |
| Application Filed: | April 02, 1993 |
| مستخلص: | 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: | Millar, Malcolm H. (Widnes, GB2); Hardy, Francis R. F. (Widnes, GB2); Morris, Gareth W. (Widnes, GB2); Crampton, John R. (Widnes, GB2) |
| Assignees: | Interox Chemicals Limited (London, GB2) |
| Claim: | We claim |
| Claim: | 1. 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. 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: | 3. A process according to claim 1 wherein the solution flows through the resin bed under gravity. |
| Claim: | 4. 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: | 5. 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: | 6. A process according to claim 1 wherein the solution is passed through the resin and/or a different resin a plurality of times. |
| Claim: | 7. A process according to claim 6 further comprising the step of changing said bed after each passage of said solution through said bed. |
| Claim: | 8. A process according to claim 6 wherein said solution is passed through said resin bed from 5 to 12 times. |
| Claim: | 9. 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: | 10. 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: | 11. A process according to claim 10 wherein the bed is retained within an inclined sidewall. |
| Claim: | 12. A process according to claim 11 wherein the sidewall comprises a mesh filter that defines a downward pointing cone. |
| Claim: | 13. A process according to claim 1 wherein the resin employed comprises a cross linked polystyrene resin bearing pendant sulphonic acid groups. |
| Claim: | 14. Apparatus for purifying an aqueous metal ion-containing hydrogen peroxide solution comprising |
| Claim: | a vessel containing a bed of ion exchange resin particles in acid form; |
| Claim: | a reservoir of metal ion-containing aqueous hydrogen peroxide solution; |
| Claim: | 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; |
| Claim: | 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 |
| Claim: | 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: | 15. 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: | 16. Apparatus according to claim 14 wherein said vessel comprises an inclined filter surface sidewall retaining said resin bed. |
| Claim: | 17. Apparatus according to claim 16 wherein the sidewall forms an inverted cone. |
| Claim: | 18. Apparatus according to claim 17 wherein said inverted cone has a cone angle of from 50.degree. to 125.degree.. |
| Claim: | 19. 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: | 20. 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: | 21. Apparatus according to claim 14 further comprising closeable outlet means for discharging said resin particles from said vessel. |
| Claim: | 22. Apparatus according to claim 14 further comprising means for conveying the purified aqueous hydrogen peroxide solution from said outlet means to said reservoir. |
| Current U.S. Class: | 210/661; 210/677; 210/263; 423/584 |
| Current International Class: | B01D 1504 |
| Patent References Cited: | 1671864 May 1928 Higgins 2366007 December 1944 D'Alelio 2676923 April 1954 Young 3074782 January 1963 Meeker et al. 3174927 March 1965 Cross et al. 3436343 April 1969 Smith 4132762 January 1979 Kim |
| Other References: | Chemical Abstracts, vol. 69, No. 14, 30 Sep. 1968, (Columbus, Ohio), p. 4990, abstract 53300d, & PL, B, 55378 (Zaklady Elektrochemiczne "Zabkowice"). |
| Primary Examiner: | Cintins, Ivars |
| Attorney, Agent or Firm: | Larson and Taylor |
| رقم الانضمام: | edspgr.05397475 |
| قاعدة البيانات: | USPTO Patent Grants |
| الوصف غير متاح. |