Spherical agglomerates based on zeolite(s), process for the production thereof and use thereof in adsorption processes or in catalysis

1. Spray-dried zeolitic agglomerates, said zeolite agglomerates having been spray-dried, and

having a content of zeolite(s) greater than or equal to 80% by mass and containing at most 20% of inert binder, measured as calcined equivalent, wherein the zeolite(s) is selected from the group consisting of A zeolites, Y zeolites, X zeolites, LSX, faujasites, and clinoptilolite, and the inert binder is a clay selected from the group consisting of kaolins, kaolinites, nacrites, dickites, halloysites, attapulgites, sepiolites, montmorillonites, bentonites, illites, metakaolins, and mixtures thereof;

having a volume mean diameter (D 50 ) of less than or equal to 600 μm;

having an apparent density ranging from 0.5 g/cm 3 to 0.8 g/cm 3 ;

having a bulk crushing strength (BCS) ranging from 0.5 MPa to 3 MPa,

having a mean roundness ranging from 85% to 100%;

having an elongation such that the percentage of particles having an elongation of 0% ranges from 10 to 100, and the percentage of particles having an elongation of less than 10% ranges from 70 to 100.

2. The spray-dried zeolitic agglomerates as claimed in claim 1 , having a volume mean diameter (D 50 ) of between 50 μm and 180 μm.

3. The spray-dried zeolitic agglomerates as claimed in claim 1 , having a volume mean diameter (D 50 ) of between 250 μm and 400 μm.

4. A coated zeolitic agglomerate, having a core which consists of one or more spray-dried zeolitic agglomerates as claimed in claim 1 and a coating.

5. A method for producing spray-dried zeolitic agglomerates according to claim 1 , which comprises the following steps:

a) mixing and suspending in water crystallites of the one or more zeolites, at least one of the binders, optionally up to 5% of the total mass of solids as calcined equivalent of one or more additives, and optionally up to 5% of the total mass of solids as calcined equivalent of a source of liquid and/or solid silica;

b) spray-drying the suspension obtained in step a) to produce spherical agglomerates in a hot gas at an inlet temperature ranging from 110° C. to 300° C., optionally followed by a step of sieving and/or cycloning;

c) calcining the agglomerates obtained in step b) at a temperature ranging from 500° C. to 600° C., optionally preceded by a second drying phase post spray-drying;

d) optionally bringing the product resulting from step c) into contact with an alkaline basic aqueous solution followed by washing;

e) optionally partial or complete ion exchange of the zeolitic agglomerates obtained in step c) or step d) followed by washing;

f) drying and activating at a temperature ranging from 200° C. to 600° C. the product derived from step d) or step e).

6. The method as claimed in claim 5 , wherein the one or more zeolites are in powdered form and have crystal size of between 0.5 μm and 20 μm.

7. A fixed adsorption bed, comprising at least one spray-dried zeolitic agglomerate as claimed in claim 1 .

8. The fixed bed as claimed in claim 7 , comprising a quantity of spray-dried zeolitic agglomerate(s) of less than 50 kg and greater than 50 g.

9. A composite material comprising, at least one spray-dried zeolitic agglomerate as claimed in claim 1 and at least one polymer matrix.

10. The composite material as claimed in claim 9 , comprising from 5% to 95% of the at least one spray-dried zeolitic agglomerate relative to the total weight of the composite material.

11. A disposable zeolitic adsorbent cartridge, comprising at least one spray-dried zeolitic agglomerate as claimed in claim 1 .

12. A transportable, mobile oxygen concentrator for respiratory assistance, comprising at least one spray-dried zeolitic agglomerate as claimed in claim 1 .

13. A disposable zeolitic adsorbent cartridge, comprising at least one spray-dried zeolitic agglomerate as claimed in claim 9 .

14. A disposable zeolitic adsorbent cartridge, comprising a fixed adsorption bed as claimed in claim 7 .

15. A transportable, mobile oxygen concentrator for respiratory assistance, comprising at least one fixed adsorption bed as claimed in claim 7 .

16. A transportable, mobile oxygen concentrator for respiratory assistance, comprising at least one composite material as claimed in claim 9 .

17. A transportable, mobile oxygen concentrator for respiratory assistance, comprising at least one cartridge as claimed in claim 11 .

18. Spray-dried zeolitic agglomerates having a content of zeolite(s) greater than or equal to 80% by mass and containing at most 20% of inert binder, measured as calcined equivalent, wherein the zeolite(s) is selected from the group consisting of A zeolites, Y zeolites, X zeolites, LSX, faujasites, and clinoptilolite, and the inert binder is a clay selected from the group consisting of kaolins, kaolinites, nacrites, dickites, halloysites, attapulgites, sepiolites, montmorillonites, bentonites, illites, metakaolins, and mixtures thereof; a volume mean diameter (D 50 ) of less than or equal to 600 μm; an apparent density ranging from 0.5 g/cm 3 to 0.8 g/cm 3 ; a bulk crushing strength (BCS) ranging from 0.5 MPa to 3 Mpa; a mean roundness ranging from 85% to 100%; and an elongation such that the percentage of particles having an elongation of 0% ranges from 10 to 100, and the percentage of particles having an elongation of less than 10% ranges from 70 to 100, which is made by a process comprising:

a) mixing and suspending in water crystallites of one or more powdered zeolite(s) selected from the group consisting of A zeolites, Y zeolites, X zeolites, LSX, faujasites, and clinoptilolite, at least one binder selected from the group consisting of kaolins, kaolinites, nacrites, dickites, halloysites, attapulgites, sepiolites, montmorillonites, bentonites, illites, metakaolins, and mixtures thereof, optionally up to 5% of the total mass of solids as calcined equivalent of one or more additives, and optionally up to 5% of the total mass of solids as calcined equivalent of a source of liquid and/or solid silica;

b) spray-drying the suspension obtained in step a) to produce spherical agglomerates in a hot gas at an inlet temperature ranging from 110° C. to 300° C, optionally followed by a step of sieving and/or cycloning;

c) calcining the agglomerates obtained in step b) at a temperature ranging from 500° C. to 600° C., optionally preceded by a second drying phase post spray-drying;

d) optionally bringing the product resulting from step c) into contact with an alkaline basic aqueous solution followed by washing;

e) optionally partial or complete ion exchange of the zeolitic agglomerates obtained in step c) or step d) followed by washing; and

f) drying and activating at a temperature ranging from 200° C. to 600° C. the product derived from step d) or step e).

19. Spray-dried spherical zeolitic agglomerates, said zeolitic agglomerates having been spray-dried, and

having a content of zeolite(s) greater than or equal to 80% by mass and containing at most 20% of inert binder, measured as calcined equivalent, wherein the zeolite(s) is selected from the group consisting of A zeolites, Y zeolites, X zeolites, LSX, faujasites, and clinoptilolite, and the inert binder is selected from the group consisting of kaolins, kaolinites, nacrites, dickites, halloysites, attapulgites, sepiolites, montmorillonites, bentonites, illites, metakaolins, and mixtures thereof;

having a volume mean diameter (D 50 ) of less than or equal to 600 μm;

having an apparent density ranging from 0.5 g/cm 3 to 0.8 g/cm 3 ;

having a bulk crushing strength (BCS) ranging from 0.5 MPa to 3 MPa,

having a mean roundness ranging from 85% to 100%;

having an elongation such that the percentage of particles having an elongation of 0% ranges from 10 to 100, and the percentage of particles having an elongation of less than 10% ranges from 70 to 100.

20. The spray-dried spherical zeolitic agglomerates of claim 19 , wherein the zeolite is selected from the group consisting of A zeolites, Y zeolites, X zeolites, and LSX.

21. The spray-dried spherical zeolitic agglomerates of claim 1 , wherein the zeolite(s) have a crystal size of between 0.5 μm and 20 μm.

22. The spray-dried spherical zeolitic agglomerates of claim 1 , wherein the spray-dried zeolitic agglomerates are made by the process of spray-drying a suspension comprising the zeolite, the inert binder, and water, and the suspension has a solids content of about 40-60%.

23. The spray-dried spherical zeolitic agglomerates of claim 19 , wherein the spray-dried zeolitic agglomerates are formed by spray-drying a suspension comprising the zeolite, the inert binder, and water, and the suspension has a solids content of about 40-60%.

24. The spray-dried spherical zeolitic agglomerates of claim 20 , wherein the zeolite is LSX.

25. The spray-dried spherical zeolitic agglomerates of claim 20 , wherein the zeolite is A zeolite.

26. The spray-dried spherical zeolitic agglomerates of claim 20 , wherein the zeolite is Y zeolite.

27. The spray-dried spherical zeolitic agglomerates of claim 20 , Wherein the zeolite is X zeolite.

28. The spray-dried zeolitic agglomerates of claim 1 , wherein the binder is selected from the group consisting of kaolinites, nacrites, dickites, halloysites, attapulgites, sepiolites, montmorillonites, illites, metakaolins, and mixtures thereof.