Chemically coated zeolite and method for chemically coating zeolite and using coated zeolite

• US 5,833,739 A
• Filed: 11/06/1995
• Issued: 11/10/1998
• Est. Priority Date: 11/13/1992
• Status: Expired due to Fees

• Current Assignee: Fernando Cadena, Fred Klatte
• Original Assignee: Fernando Cadena, Fred Klatte
• Inventors: Cadena, Fernando, Klatte, Fred
• Primary Examiner(s): Lewis, Michael L.
• Assistant Examiner(s): DUNN, THOMAS G
• Application Number:
  US08/554,198
• Time in Patent Office: 1,100 Days
• Field of Search: 502/62, 502/64, 502/60, 95/141, 95/116, 95/136, 95/902, 210/691
• US Class Current: 95/136
• CPC Class Codes: A23K 20/105 Aliphatic or alicyclic compounds
• CPC Class Codes: A23K 20/142 Amino acids; Derivatives thereof
• CPC Class Codes: A23K 20/174 Vitamins
• CPC Class Codes: A23K 20/30 Oligoelements
• CPC Class Codes: B01D 46/00 Filters or filtering processes specially modified for separating dispersed particles from gases or vapours filtering elements B01D24/00-B01D35/00; filtering material B01D39/00; their regeneration outside the filters B01D41/00
• CPC Class Codes: B01D 53/02 by adsorption, e.g. preparative gas chromatography solid sorbent compositions B01J20/00, preparation of inorganic compounds or elements C01
• CPC Class Codes: B01D 53/885 Devices in general for catalytic purification of waste gases
• CPC Class Codes: B01J 20/183 Physical conditioning without chemical treatment, e.g. drying, granulating, coating, irradiation
• CPC Class Codes: B01J 29/40 of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively
• CPC Class Codes: B01J 37/0221 of particles
• CPC Class Codes: Y10S 95/902 Molecular sieve

Abstract

A process for coating zeolite crystals with paraffin, a wax other than paraffin, a fat or oil, or a mixture of at least one QAC and a wax, fat, or oil. Preferably, the crystals are dehydrated until they have about 5% moisture content, and are then mixed with paraffin to produce paraffin-coated zeolite crystals having a desired content of paraffin. When the coated zeolite crystals are used for removing benzene from contaminated water, their paraffin content is preferably about 8% (by weight). Other embodiments are methods for using zeolite coated with paraffin, another wax, a fat, an oil, or a mixture of at least one QAC and a wax, fat, or oil to filter a contaminant from contaminated liquid or gas. The zeolite crystals are optionally impregnated with a chemical such as permanganate before they are coated with the desired wax, fat, oil or mixture. A zeolite crystal having pores coated with wax, fat, oil, or a mixture of at least one QAC and wax, fat, or oil is within the scope of the invention. Another aspect of the invention is a method of filtering contaminants from fluid by exposing the fluid to zeolite crystals coated with a wax, fat, oil, or a mixture of at least one QAC and wax, fat, or oil.

Claims

1. A zeolite crystal coated with a substance, produced as a result of a method including the steps of:

(a) dehydrating zeolite crystals containing at least some water to decrease their moisture content below their initial moisture content, thereby producing dehydrated zeolite crystals; and

(b) after step (a), mixing the dehydrated zeolite crystals with the substance, thereby producing zeolite crystals coated with the substance, wherein said substance is selected from the group consisting of waxes, mixtures of at least one QAC and at least one wax, mixtures of at least one QAC and at least one fat, and mixtures of at least one QAC and at least one oil.

2. A method, including the steps of:

(a) impregnating zeolite crystals with a first substance selected from the group consisting of permanganates and quaternary ammonium cations, thereby producing impregnated zeolite crystals; and

(b) after step (a), mixing the impregnated zeolite crystals with a second substance in a liquid state selected from the group consisting of waxes, fats, oils, mixtures of at least one QAC and at least one wax, mixtures of at least one QAC and at least one fat, and mixtures of at least one QAC and at least one oil, thereby producing impregnated zeolite crystals coated with the second substance.

3. The method of claim 2, wherein the second substance is paraffin.

4. The method of claim 3, wherein the zeolite crystals coated with paraffin have a paraffin content of from 7% to 9% by weight.

5. The method of claim 4, wherein the zeolite crystals coated with paraffin have a paraffin content of 8% by weight.

6. A zeolite crystal coated with paraffin, produced as a result of the method of claim 3.

7. The method of claim 2, wherein the second substance has a melting point, and also including the step of:

(c) after step (b), cooling the zeolite crystals coated with the second substance to below the melting point of said second substance.

8. A zeolite crystal coated with said second substance, produced as a result of the method of claim 2.

9. The method of claim 2, wherein step (a) includes the step of impregnating the zeolite crystals with a permanganate.

10. The method of claim 2, also including the step of:

exposing the impregnated zeolite crystals coated with the second substance to a contaminated fluid that is a member of the group consisting of contaminated air and contaminated water, to absorb from the contaminated fluid a contaminant that is an organic chemical.

11. The method of claim 10, wherein the contaminant is benzene.

12. The method of claim 10, wherein the contaminant is toluene.

13. The method of claim 10, wherein the contaminant is xylene.

14. The method of claim 2, also including the step of:

exposing the impregnated zeolite crystals coated with the second substance to a contaminated fluid that is a member of the group consisting of contaminated air and contaminated water, to absorb from the contaminated fluid a contaminant that is a member of the group consisting of hydrogen sulfide, acetone, ethylene glycols, and formaldehyde.

15. A zeolite crystal coated with at least one substance selected from the group consisting of waxes, mixtures of at least one QAC and at least one wax, mixtures of at least one QAC and at least one fat, and mixtures of at least one QAC and at least one oil.

16. The crystal of claim 15, wherein said at least one substance is a wax.

17. The crystal of claim 15, wherein said at least one substance is paraffin.

18. The crystal of claim 17, having a paraffin content of from 7% to 9% by weight.

19. The crystal of claim 18, having a paraffin content of 8% by weight.

20. The crystal of claim 15, having a size sufficient for filtering a contaminant from a contaminated fluid.

21. A method, including the steps of:

(a) dehydrating zeolite crystals containing at least some water to decrease their moisture content below their initial moisture content, thereby producing dehydrated zeolite crystals;

(b) after step (a), mixing the dehydrated zeolite crystals with a substance selected from the group consisting of waxes, fats, oils, mixtures of at least one QAC and at least one wax, mixtures of at least one QAC and at least one fat, and mixtures of at least one QAC and at least one oil, thereby producing zeolite crystals coated with the substance; and

exposing the zeolite crystals coated with said substance to a contaminated fluid that is a member of the group consisting of contaminated air and contaminated water, to absorb from the contaminated fluid a contaminant that is an organic chemical.

22. A method, including the steps of:

(a) applying a substance in solid form to the zeolite crystals, said substance having a melting point, and said substance being selected from the group consisting of waxes, fats, oils, mixtures of at least one QAC and at least one wax, mixtures of at least one QAC and at least one fat, and mixtures of at least one QAC and at least one oil;

(b) after step (a), mixing the zeolite crystals with the substance, thereby producing a mixture;

(c) heating the mixture to a temperature above the melting point of the substance, thereby producing zeolite crystals coated with the substance; and

exposing the zeolite crystals coated with said substance to a contaminated fluid that is a member of the group consisting of contaminated air and contaminated water, to absorb from the contaminated fluid a contaminant that is an organic chemical.

23. The method of claim 22, wherein the contaminant is benzene.

24. The method of claim 22, wherein the contaminant is toluene.

25. The method of claim 22, wherein the contaminant is xylene.

26. A method, including the steps of:

(a) dehydrating zeolite crystals containing at least some water to decrease their moisture content below their initial moisture content, thereby producing dehydrated zeolite crystals;

(b) after step (a), mixing the dehydrated zeolite crystals with a substance selected from the group consisting of waxes, fats, oils, mixtures of at least one QAC and at least one wax, mixtures of at least one QAC and at least one fat, and mixtures of at least one QAC and at least one oil, thereby producing zeolite crystals coated with the substance; and

exposing the zeolite crystals coated with said substance to a contaminated fluid that is a member of the group consisting of contaminated air and contaminated water, to absorb from the contaminated fluid a contaminant that is a member of the group consisting of hydrogen sulfide, acetone, ethylene glycols, and formaldehyde.

27. A method, including the steps of:

(a) applying a substance in solid form to the zeolite crystals, said substance having a melting point, and said substance being selected from the group consisting of waxes, fats, oils, mixtures of at least one QAC and at least one wax, mixtures of at least one QAC and at least one fat, and mixtures of at least one QAC and at least one oil;

(b) after step (a), mixing the zeolite crystals with the substance, thereby producing a mixture;

(c) heating the mixture to a temperature above the melting point of the substance, thereby producing zeolite crystals coated with the substance; and

exposing the zeolite crystals coated with said substance to a contaminated fluid that is a member of the group consisting of contaminated air and contaminated water, to absorb from the contaminated fluid a contaminant that is a member of the group consisting of hydrogen sulfide, acetone, ethylene glycols, and formaldehyde.