Adsorbent for water removal from ammonia

• US 20040009873A1
• Filed: 07/09/2002
• Published: 01/15/2004
• Est. Priority Date: 07/09/2002
• Status: Active Grant

• Current Assignee: Versum Materials US Inc.
• Original Assignee: Air Products and Chemicals Incorporated (Linde Plc)
• Inventors: Dong, Chun Christine, Rao, Madhukar Bhaskara, Wu, Dingjun
• Granted Patent: US 7,446,078 B2
• Time in Patent Office: Days
• US Class Current: 502/406
• CPC Class Codes: B01J 20/0211 Compounds of Ti, Zr, Hf
• CPC Class Codes: B01J 20/0222 Compounds of Mn, Re
• CPC Class Codes: B01J 20/0225 Compounds of Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt
• CPC Class Codes: B01J 20/0229 Compounds of Fe
• CPC Class Codes: B01J 20/0244 Compounds of Zn
• CPC Class Codes: B01J 20/0248 Compounds of B, Al, Ga, In, Tl B01J20/08 takes precedence
• CPC Class Codes: B01J 20/0281 Sulfates of compounds other than those provided for in B01J20/045
• CPC Class Codes: B01J 20/0288 Halides of compounds other than those provided for in B01J20/046
• CPC Class Codes: B01J 20/045 containing sulfur, e.g. sulfates, thiosulfates, gypsum
• CPC Class Codes: B01J 20/046 containing halogens, e.g. halides
• CPC Class Codes: B01J 20/08 comprising aluminium oxide or hydroxide; comprising bauxite
• CPC Class Codes: B01J 20/28057 Surface area, e.g. B.E.T specific surface area
• CPC Class Codes: B01J 20/28078 Pore diameter
• CPC Class Codes: B01J 20/3204 Inorganic carriers, supports or substrates
• CPC Class Codes: B01J 20/3234 Inorganic material layers
• CPC Class Codes: B01J 20/3236 containing metal, other than zeolites, e.g. oxides, hydroxides, sulphides or salts
• CPC Class Codes: B01J 20/3441 Regeneration or reactivation by electric current, ultrasound or irradiation, e.g. electromagnetic radiation such as X-rays, UV, light, microwaves
• CPC Class Codes: B01J 20/3483 by thermal treatment not covered by groups B01J20/3441 - B01J20/3475, e.g. by heating or cooling
• CPC Class Codes: C01C 1/024 Purification
• CPC Class Codes: C01P 2006/82 water content

Abstract

The present invention provides an adsorbent for removing water and/or other oxygen-containing impurities from a fluid comprising ammonia to the ppb level and methods for making and using same. The adsorbent preferably comprises a substrate having a plurality of pores and a surface area that ranges from about 100 to about 2,500 m²/g and a compound disposed within a least a portion of the substrate. In certain preferred embodiments, the compound comprises at least one cation from the group consisting of ammonium (I), lithium (I), sodium (I), potassium (I), cesium (I); magnesium (II), calcium (II), strontium (II), barium (II), manganese (II), nickel (II), iron (II), zinc (II); aluminum (III), indium (III), iron (III), and zirconium (IV) or combinations thereof that is ionically associated with an anion from the group consisting of halide, sulfide, sulfite, or sulfate.

Claims

1. An adsorbent for removing water from a fluid comprising ammonia, the absorbent comprising:

a substrate having a plurality of pores and a surface area that ranges from about 100 to about 2,500 m²/g; and

a compound disposed within at least a portion of the substrate, the compound comprising at least one cation selected from the group consisting of ammonium (I), lithium (I), sodium (I), potassium (I), cesium (I);

magnesium (II), calcium (II), strontium (II), barium (II), manganese (II), nickel (II), iron (II), zinc (II);

aluminum (III), indium (III), iron (III), and zirconium (IV) or combinations thereof that is tonically associated with an anion from the group consisting of halide, sulfide, sulfite and sulfate.

2. The adsorbent of claim 1 wherein the surface area ranges from about 100 to about 1,500 m²/g.

3. The adsorbent of claim 2 wherein the surface area ranges from about 100 to about 1,200 m²/g.

4. The adsorbent of claim 1 wherein the average pore size within the substrate ranges from about 8 to about 500 Angstroms.

5. The adsorbent of claim 1 wherein the weight percentage of compound disposed within the substrate ranges from about 1 to about 80%.

7. The adsorbent of claim 1 wherein the cation comprises ammonium.

8. The adsorbent of claim 7 wherein the anion comprises sulfate.

9. The adsorbent of claim 1 wherein the substrate is selected from the group consisting of alumina, activated carbon, or zeolite.

10. An apparatus for removing water from NH₃, the apparatus comprising the adsorbent of claim 1.

6. The adsorbent of claim 6 wherein the weight percentage of compound disposed within the substrate ranges from about 2 to about 50%.

11. A method for preparing an adsorbent for removing water from ammonia, the method comprising:

providing a mixture comprising at least one cation selected from the group consisting of ammonium (I), lithium (I), sodium (I), potassium (I), cesium (I);

magnesium (II), calcium (II), strontium (II), barium (II), manganese (II), nickel (II), iron (II), zinc (II);

aluminum (III), indium (III), iron (III), and zirconium (IV) or combinations thereof that is tonically associated with an anion from the group consisting of halide, sulfide, sulfite, and sulfate;

impregnating a porous substrate with the mixture to form an adsorbent precursor; and

heating the adsorbent precursor to a temperature of at least about 100°

C. or greater to form the adsorbent.

12. The method of claim 11 wherein the mixture further comprises a solvent.

13. The method of claim 12 wherein the method further comprises the step of removing the solvent from the adsorbent precursor.

14. The method of claim 13 wherein the removing and heating are conducted simultaneously.

15. The method of claim 11 wherein the heating is conducted under vacuum conditions.

16. The method of claim 11 wherein the heating is conducted in a nitrogen atmosphere.

17. The method of claim 11 wherein the heating is conducted in an inert atmosphere.

18. The method of claim 11 wherein the substrate is selected from the group consisting of alumina, activated carbon, or zeolite.

19. A method for preparing an adsorbent comprising at least one cation ionically associated with at least one anion, the method comprising:

providing a compound precursor having at least one cation is selected from the group consisting of ammonium (I), lithium (I), sodium (I), potassium (I), cesium (I);

magnesium (II), calcium (II), strontium (II), barium (II), manganese (II), nickel (II), iron (II), zinc (II);

aluminum (III), indium (III), iron (III), and zirconium (IV) or combinations thereof;

depositing the compound precursor on at least a portion of a porous substrate to form an adsorbent precursor;

heating the adsorbent precursor to a temperature of at least about 100°

C. or greater in a gaseous atmosphere to provide an anion from the group consisting of halide, sulfide, sulfite, or sulfate; and

reacting the at least one cation and an anion under temperature conditions sufficient to form the adsorbent.

20. The method of claim 19 wherein the gaseous atmosphere comprises a halide gas, a sulfur-containing gas, or combinations thereof.

21. The method of claim 19 wherein the substrate is selected from the group consisting of alumina, activated carbon, or zeolite.

22. A method of removing water from a fluid comprising ammonia and water wherein the water contained within the fluid is at a partial pressure ranging from about 10⁻

9 atm to about 9×

10<sup>−

4</sup> atm by passing the fluid over an adsorbent comprising from about 1 to about 80% of a compound disposed within at least a portion of a porous substrate at temperatures ranging from about −

40°

to about 70°

C. wherein the compound comprises at least one cation selected from the group consisting of ammonium (I), lithium (I), sodium (I), potassium (I), cesium (I);

magnesium (II), calcium (II), strontium (II), barium (II), manganese (II), nickel (II), iron (II), zinc (II);

aluminum (III), indium (III), iron (III), and zirconium (IV) or combinations thereof that is ionically associated with an anion from the group consisting of halide, sulfide, sulfite and sulfate.

23. The method of claim 22 wherein the adsorbent is regenerable.

24. The method of claim 22 wherein the compound is at least one selected from the group consisting of ammonium sulfate, cesium sulfate, calcium sulfate, or zirconium sulfate.

25. The method of claim 22 wherein the fluid comprises a liquid.