# US 2015/0306565 A1 · Zeolitic adsorbents, their process of preparation and their uses

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- Number: US 2015/0306565 A1
- Document ID: US20150306565A1
- Status: Published application
- Kind: A1
- Application number: 14/650,780
- Filed: 2013-12-10
- Published: 2015-10-29
- Earliest claimed: 2012-12-12
- Assignees: Ceca S.A.; Ifp Energies Nouvelles
- Applicants: Ceca S.A; Ifp Energies Nouvelles
- Inventors: Ludivine BOUVIER; Stephane KIEGER; Catherine LAROCHE; Philibert LEFLAIVE
- Web page: https://patentgrep.com/patent/US20150306565A1

## CPC

- B01J 20/18: Synthetic zeolitic molecular sieves
- B01J 20/183: {Physical conditioning without chemical treatment, e.g. drying, granulating, coating, irradiation}
- B01J 20/186: {Chemical treatments in view of modifying the properties of the sieve, e.g. increasing the stability or the activity, also decreasing the activity}
- B01J 20/28004: {Sorbent size or size distribution, e.g. particle size}
- B01J 20/28011: {Other properties, e.g. density, crush strength}
- B01J 20/2803: {Sorbents comprising a binder, e.g. for forming aggregated, agglomerated or granulated products}
- B01J 20/3007: {Moulding, shaping or extruding}
- B01J 20/3042: {Use of binding agents; addition of materials ameliorating the mechanical properties of the produced sorbent}
- B01J 20/3071: {Washing or leaching}
- B01J 20/3078: {Thermal treatment, e.g. calcining or pyrolizing}
- C07C 7/13: by molecular-sieve technique
- C07C 29/76: by physical treatment
- C07C 37/82: by solid-liquid treatment; by chemisorption
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS

## Abstract

The present invention relates to zeolitic adsorbents based on small agglomerated crystals of zeolite X comprising barium, combining optimum properties in terms of selectivity and of mechanical strength. These adsorbents have applications in the separation of fractions of aromatic C8 isomers and in particular xylenes, in the separation of substituted toluene isomers, such as nitrotoluene, diethyltoluene or toluenediamine, in the separation of cresols and in the separation of polyhydric alcohols, such as sugars.

## Claims

### Claim 1

An agglomerated zeolitic adsorbent, based on crystals of zeolite X and on at least one non-zeolitic phase, wherein:
the crystals of zeolite X exhibit:
i. a number-average diameter of less than or equal to 1.7 μm
ii. an Si/Al atomic ratio of between 1.00 and 1.50, limits included,
the content by weight of non-zeolitic phase (NZP) is such that 2.0%<NZP<5.0%, by weight of the total weight of the adsorbent,
the content by weight of barium oxide (BaO) is greater than 23%, with respect to the total weight of the adsorbent,
the content by weight of potassium oxide K2O is less than 9%, with respect to the total weight of the adsorbent, and
the total content by weight of oxides of alkali metal or alkaline earth metal ions, other than BaO and K2O, is less than 5% with respect to the total weight of the adsorbent.

### Claim 2 (depends on 1)

An adsorbent according to claim 1, wherein the number-average diameter of the crystals of zeolites X is between 0.1 μm and 1.5 μm, limits included.

### Claim 3 (depends on 1)

An absorbent according to claim 1, wherein the content of barium oxide (BaO) is between 33% and 42%, limits included, by weight, with respect to the total weight of the adsorbent.

### Claim 4 (depends on 1)

An absorbent according to claim 1, the loss on ignition of which, measured at 950° C. according to Standard NF EN 196-2 is between 4.0% and 7.7%, limits included.

### Claim 5 (depends on 1)

An absorbent according to claim 1, in the form of agglomerates, the number-average diameter of which is between 0.4 mm and 2 mm, limits included.

### Claim 6 (depends on 1)

A process for the preparation of an adsorbent according to claim 1, comprising at least the stages of:
a) agglomeration of crystals of zeolite X with a number-average diameter of less than or equal to 1.7 μm, with an Si/Al atomic ratio of between 1.00 and 1.50, limits included, with a zeolitisable binder comprising at least 80% by weight of zeolitisable clay and with a source of silica, then shaping of agglomerates and, finally, drying and calcination of said agglomerates,
b) zeolitization of the said zeolitisable binder by bringing the agglomerates obtained in stage a) into contact with a basic alkaline solution,
c) cationic exchange of the agglomerates of stage b) by bringing the agglomerates into contact with a solution of barium ions or of barium ions and potassium ions,
d) optional cationic exchange by bringing the agglomerates of stage c) into contact with a solution of potassium ions,
e) then washing and drying the agglomerates thus obtained, and
f) production of the zeolitic adsorbent by activation of the agglomerates obtained in stage e).

### Claim 7 (depends on 6)

A process according to claim 6, in which stage b) of zeolitization is carried out with an alkaline solution, the concentration of which is between 0.5M and 5M.

### Claim 8 (depends on 6)

A process according to claim 6, in which stage b) of zeolitization is carried out for a period of time of between 1 hour and 8 hours.

### Claim 9 (depends on 6)

An absorbent obtained according to the process of claim 6.

### Claim 10 (depends on 1)

A process for using an adsorbent according to claim 1 wherein the process comprises:
separating fractions of aromatic C8 isomers,
separating substituted toluene isomers,
separating cresols, or
separating polyhydric alcohols.

### Claim 11 (depends on 10)

A process according to claim 10, wherein the process comprises separating para-xylene from fractions of aromatic isomers having 8 carbon atoms.

### Claim 12 (depends on 1)

A process for the recovery of para-xylene from fractions of aromatic hydrocarbon isomers comprising 8 carbon atoms, in the liquid phase, by adsorption of the para-xylene using an adsorbent according to claim 1, in the presence of a desorbent.

### Claim 13 (depends on 12)

A process according to claim 12, wherein the process is a simulated moving bed process.

### Claim 14 (depends on 12)

A process according to claim 12, wherein the process is a simulated countercurrent process.

### Claim 15 (depends on 12)

A process according to claim 12, wherein the process is a simulated cocurrent process.

### Claim 16 (depends on 1)

A process for the recovery of para-xylene from fractions of aromatic hydrocarbon isomers comprising 8 carbon atoms, in the gas phase, by adsorption of the para-xylene using an adsorbent according to claim 1, in the presence of a desorbent.

### Claim 17 (depends on 12)

A process for the recovery of para-xylene according to claim 12, wherein the desorbent is selected from the group consisting of toluene and para-diethylbenzene.

### Claim 18 (depends on 1)

A process for the separation of polyhydric alcohols, wherein the process employs an adsorbent according to claim 1.

### Claim 19 (depends on 1)

A process for the separation of substituted toluene isomers, wherein the process employs an adsorbent according to claim 1.

### Claim 20 (depends on 1)

A process for the separation of cresols, wherein the process employs an adsorbent according to claim 1.