Separation of gases from air
The present invention relates to the use of a zeolitic adsorbent material based on faujasite (FAU) zeolite crystals, the Si/AI mole ratio of which is between 1.00 and 1.20, and the non-zeolitic phase (NZP) content of which is such that 0<NZP≤25%, for the non-cryogenic separation of industrial gases by (V)PSA, in particular of the air gases. The invention also relates to respiratory assistance machines comprising at least said zeolitic adsorbent material.
1 . A method for non-cryogenic separation of industrial gases by (V) PSA and for industrial preparation of oxygen by (V) PSA, comprising contacting the industrial gases with a zeolitic adsorbent material, where the zeolitic adsorbent material:
is based on faujasite (FAU) zeolite crystals, the Si/Al mole ratio of which is between 1.00 and 1.13, limits inclusive, where the crystals are chosen from NaLSX type crystals and NaMSX type crystals,
has a content of non-zeolite phase (NZP) such that 0<NZP≤10%, by weight relative to the total weight of the zeolitic adsorbent material,
is present as adsorbent layers, and
has a bulk density of between 0.55 g·cm −3 and 0.70 g·cm −3 ,
wherein sodium content of the zeolitic adsorbent material is greater than 95%, limits inclusive, the sodium content being expressed as a percentage of exchangeable sites, and
wherein the zeolitic adsorbent material has a measured nitrogen (N 2 ) mass adsorption capacity under 4 bar (0.4 MPa) at 25° C. of greater than 23 Ncm 3 ·g −1 .
2 . The method as claimed in claim 1 , wherein the zeolitic adsorbent material has a volume-mean diameter of less than or equal to 7 mm.
3 . The method as claimed in claim 1 , where the zeolitic adsorbent material is present as an adsorption element in oxygen concentrators for respiratory assistance.
4 . The method as claimed in claim 1 , wherein other adsorbent(s) are present and comprise zeolites chosen from CaLSX, LiTrLSX, 5A, NaX, LiX, LiAgLSX, LiLSX and LiCaLSX.
5 . The method as claimed in claim 1 , wherein the adsorbent is present in a double layer with another adsorbent based on LiLSX, forming a NaLSX/LiLSX or NaMSX/LiLSX double layer, wherein the NaLSX/LiLSX ratio is between 5/95 and 95/5.
6 . A transportable or mobile oxygen concentrator for respiratory assistance comprising at least one zeolitic adsorbent material, where the zeolitic adsorbent material:
is based on faujasite (FAU) zeolite crystals, the Si/Al mole ratio of which is between 1.00 and 1.13, limits inclusive, where the crystals are chosen from NaLSX type crystals and NaMSX type crystals,
has a content of non-zeolite phase (NZP) such that 0<NZP≤25%, by weight relative to the total weight of the zeolitic adsorbent material,
is present as adsorbent layers, and
has a bulk density of between 0.55 g·cm −3 and 0.70 g·cm −3 , and
wherein sodium content of the zeolitic adsorbent material is greater than 95%, limits inclusive, the sodium content being expressed as a percentage of exchangeable sites, and
wherein the zeolitic adsorbent material has a measured nitrogen (N 2 ) mass adsorption capacity under 4 bar (0.4 MPa) at 25° C. of greater than 23 Ncm 3 ·g −1 .
7 . The concentrator according to claim 6 , comprising a NaLSX/LiLSX or NaMSX/LiLSX double layer, wherein the NaLSX/LiLSX ratio is between 5/95 and 95/5.