Zeolitic adsorbent for high productivity xylene separation
OwnerLudivine BOUVIER, Maria MANKO +1inventors
InventorsLudivine BOUVIER, Maria MANKO, Javier PEREZ-PELLITERO
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Abstract
The invention relates to agglomerated zeolitic adsorbents based on Faujasite X type zeolite crystals with a controlled Si/Al molar ratio, exchanged with barium; or based on Faujasite X type zeolite with a controlled Si/Al molar ratio, exchanged with barium and potassium. The invention also relates to the use of the adsorbent in the separation of sugars, polyhydric alcohols, substituted toluene isomers, cresols, or for the recovery of very high purity para-xylene; and to the separation process for separating xylenes that implements the use of the adsorbent.
Claims15
An agglomerated zeolitic adsorbent based on MSX zeolite crystals, having an Si/Al atomic ratio such that 1.10≤Si/Al≤1.18, preferably 1.10≤Si/Al≤1.17, more preferably 1.10≤Si/Al≤1.16, more preferably 1.11≤Si/Al≤1.16, of which at least 90%, preferably at least 95% of the exchangeable cationic sites are occupied, either by barium ions alone or by barium ions and potassium ions.
An agglomerated zeolitic adsorbent according to one of the preceding claims, that has a size distribution such that the number-average diameter is between 0.4 mm and 2.0 mm, preferably between 0.4 mm and 0.8 mm.
An agglomerated zeolitic adsorbent according to one of the preceding claims, of which the mechanical strength, as measured by the Shell method series SMS1471-74 that is appropriate for agglomerates having a size that is less than 1.6 mm, is greater than or equal to 2 MPa, preferably greater than or equal to 2.5 MPa.
An agglomerated zeolitic adsorbent according to one of the preceding claims, whereof the loss on ignition as measured at 900° C. is less than or equal to 7.7%, preferably between 0 and 7.7%, in a preferable manner between 3.0% and 7.7%, in an even more preferable manner between 3.5% and 6.5%, and advantageously between 4.5% and 6.0%, inclusive of limits.
An agglomerated zeolitic adsorbent according to one of the preceding claims, in which the MSX zeolite crystals have a number average diameter of between 0.01 μm and 5 μm, preferably between 0.05 μm and 5 μm, in a highly preferable manner between 0.1 μm and 4 μm, in an even more preferable manner between 0.1 μm and 3 μm, and in an even more preferable manner between 0.1 μm and 2 μm.
The use of an agglomerated zeolitic adsorbent based on MSX zeolite crystals having an Si/Al atomic ratio such that 1.10≤Si/Al≤1.18, preferably 1.10≤Si/Al≤1.17, even more preferably 1.10≤Si/Al≤1.16, even more preferably 1.11≤Si/Al≤1.16, of which at least 90% of the exchangeable cationic sites are occupied, either by barium ions alone or by barium ions and potassium ions, for the separation of sugars, polyhydric alcohols, substituted toluene isomers, cresols, or for the recovery of para-xylene, in the presence of a desorbent, which is preferably either toluene or para-diethylbenzene, in liquid phase or in gas phase.
Dependencies are inferred from the claim text.