ZEOLITE ADSORBENTS HIGH OUTER SURFACE, PROCESS FOR THEIR PREPARATION AND USES THEREOF

[0001] The invention relates to the use of zeolitic adsorbent materials in the form of agglomerates comprising at least one zeolite type A, said adsorbent a large exterior surface characterized by nitrogen adsorption, and a microporous high volume, for the gas phase separation, in particular in methods modulated pressure, or PSA (Adsorption pressure swing or "Pressure swing adsorption" English language) is of the VSA type (Adsorption modulated vacuum or "Vacuum swing adsorption" English language), or VPSA (hybrid method of previous 2), either ("Rapid Pressure swing adsorption" English language), in methods modulated temperature TSA type (adsorption temperature swing or "Temperature swing adsorption" English language) and/or in methods and modulated pressure type temperature PTSA (Adsorption modulated Pressure and temperature or "Pressure and Temperature swing adsorption" English language).

[0002] The present invention also relates to a method for gas separation and purification using zeolite adsorbents having a large outer surface.

[0003] The invention also provides materials zeolitic adsorbents can be used in the present invention, comprising potassium and/or calcium and/or sodium.

[0004] The use of this type of agglomerates is particularly advantageous in applications where the kinetics of transfer, the volume capacity of adsorption, parameters critical to the efficiency and overall productivity of the method, as well as lower friction losses are searched.

[0005] In technologies adsorptive separation, much has been to pool in recent years in order to increase the productivity schedule of adsorbent beds, in particular by increasing the frequency of the adsorption/desorption cycles, which means that the adsorbent implemented, in addition to its thermodynamic properties of adsorption, must be saturate by adsorption to the desorption and render the gas adsorbed into period of time short. The adsorbents must be so constructed as to have mass transfer in the most efficient, i.e. such that the gas to be separated or purifying reach as quickly as possible the adsorption sites and are also desorbed as quickly as possible.

[0006] Several tracks have been scanned order to obtain this object. The first method proposed by literature involves reducing the size of adsorbent particles. It is generally accepted that can allow more rapid diffusion of gases in the macroporous network, the kinetic constant material transfer is inversely proportional to the square of the particle diameter (or equivalent dimension, according to the morphology of the adsorbents). An illustrative for example the article " particle size effects in the separation of air by fast pressure swing adsorption", of. and al, Chemical Engineering Science, 49 (18), 3059-3075, (1994).

[0007] WO2008/152319 The document describes the preparation, spray, adsorbents mechanical strength of small sizes, which are used for example in portable medical oxygen concentrators, as shown in the document US2013/0216627. The main drawback of the reduction of the size of the adsorbent particles is the increase frictional losses in the adsorbers and the large power consumption associated therewith. This is particularly inhibitive in the adsorption processes for industrial production of gas.

[0008] The second method is a method of enhancing the transferability intra-granular adsorbents, without changing their size. Requests international JP2157119, and describe JP2002068732 WO2002/49742 adsorbers improved kinetic obtained by conversion of active material zeolite of the agglomeration binder and related methods of gas separation, than with conventional particles.

[0009] The document W02008/051904 relates to a method of producing by extrusion/spheronization of balls of adsorbents zeolite zeolite improved diffusion. The document W02008/109882 described in turn the preparation of adsorbents high strength and improved mass transfer from zeolites and less than 15% binder introduced silicic in colloidal form.

[0010] The request EP1240939 calls for the selection method for uses in PSA or VSA adsorbents having a certain ratio between their kinetic constants transport Adsorbable compounds in the gas phase and the solid phase. The document US6328786 defines a minimum threshold of mechanical strength and a kinetic coefficient beyond which the adsorbents are preferred for use in PSA process. The request EP1048345 described adsorbents with high macroporosity manufactured by a spheronization technique and lyophilization.

[0011] A third method is a method of enhancing access to the adsorbent using different geometries of shaping combining both reduced thicknesses of active material and sections of passage of the fluid sufficiently wide to permit a flow with low load losses. Include tissue the sheets and adsorbents, the honeycomb type monoliths, foams or other.

[0012] FR2794993 The document provides for the use of balls heterogeneous, with a peripheral layer adsorbent coating a thin inert core: the diffusion distance is reduced, without increasing the charge losses. The system has the fault be a low volume efficiency: a substantial portion of the adsorber is occupied by inert material to the direction of the adsorption, which has a significant impact in terms of dimensions of the facilities and thus investment, or weight, which can be disturbing, in the case of purification/separation apparatus portable, such as for example medical oxygen concentrators.

[0013] Requests patent US2013/0052126 US2012/0093715 and teach that can be formed with a monolithic zeolite structures hierarchical structure, by addition of a polymer to the reaction medium of synthesis: as for the tissue sheets and adsorbents, the solids obtained have a macroporous and mesoporous volume a volume very large, the solids are very sparse and their volume efficiency is low, due to their low adsorption capacity volume.

[0014] Therefore, all these geometries adsorbent of various nature problems of implementation relatively complex, mechanical strength fatigue or attrition and low volume efficiency, since the active material content is often reduced to inert binders or other reinforcing fibers or mechanical since the resulting materials are very sparse.

[0015] It remains a need for zeolite adsorbents useful for the separation and purification of gases with good transfer properties which do not have the drawbacks associated with the use of adsorbants of the prior art. In particular, there remains a need for a zeolitic adsorbent having capabilities and improved adsorption kinetic adsorption/desorption, enabling in particular to use more intensive methods, including methods and PSA, TSA or VPSA.

[0016] The inventors have now been found that the above objects can be achieved in whole or at least in part due to uses adsorbents specifically, dedicated to separation and purification of gases such that they will be described now.

[0017] Therefore, and according to a first aspect, the invention relates to the use for the separation and/or drying gases, of at least one material comprising at least one zeolitic adsorbent zeolite type A, said adsorbent having:

_AOE280A2AO> an outer surface, as measured by nitrogen adsorption and expressed as^{2 m per gram of} adsorbent, greater than 20 m .g 2 '^1, and preferably between 20 m .g 2'^{1 and} 300 m .g 2 '^1, and particularly preferably between 30 m .g 2'^{1 and2 250 m .g} '^{1 and} even more preferably between 40 m .g 2'^{1 m .g 2 and} 200 '^1, and particularly between 50 m .g 2'^{1 m .g 2 and} 200'^1,

_AOE280A2AO> phase content by non-zeolite (PNZ), such that 0 < PNZ ≤ 30%, preferably 3% ≤ PNZ ≤ 25%, more preferably 3% ≤ PNZ ≤ 20%, advantageously 5% ≤ PNZ ≤ 20%, more preferably 7% ≤ PNZ ≤ 18%, measured by DRX (by Diffraction Spokes X), by weight relative to the total weight of the adsorbent,

_AOE280A2AO> and atomic ratio Si/Al of the adsorbent between 1.0 and 2.0, preferably between 1.0 and 1.6, and most preferably, between 1.0 and 1.4,

the set of measurements are made on the adsorbent material exchanged at least 90% calcium.

[0018] In the present disclosure, the term "zeolite type A" LTA denotes a zeolite. In a preferred embodiment, zeolite A is a mesoporous zeolite A chosen from zeolites , 4A and 5A. For "3A", is meant a zeolite having a pore opening is about 3Â; by "4A", is meant a zeolite having a pore opening is about 4Â; and by "5A", is meant a zeolite having a pore opening is about 5 Â.

[0019] According to one embodiment of the invention, the adsorbent material zeolite may also include one or more other zeolite (s) (s) selected from zeolites FAU-type (LSX, MSX, X, Y), of type LTA, CHA-type ( ), type HEU (Clinoptilolite), and mixtures of two or more of, and more preferably from zeolites , , 5A, and mixtures of two or more of them. Other zeolites may be present in minor amounts in the adsorbents of the invention or for use in the method of the invention. These zeolites may be considered as two pollutants, in particular because they do not contribute to adsorption of gases, i.e. that they are inert to the adsorption of the gas. These zeolites include, by way of non-limiting example, sodalite, the hydroxysodalite, zeolite P, and other zeolites inert to adsorption of gases.

[0021] The different types of zeolites present in the zeolite adsorbent material are determined by DRX. The amount of zeolites is also measured by DRX and is expressed in % by weight relative to the total weight of the zeolite adsorbent material.

[0022] As a corollary, in the present invention, the term "non-zeolite phase" (or "PNZ") denotes any phase present in the adsorbent material, other than the zeolite (s) (s) defined above, referred to as "zeolite phase" or "PZ". The amount of non-zeolite phase is expressed by the complement to 100% of the zeolite phase of the adsorbent, i.e.:

- = 100% AND % PZ,

wherein % PNZ represents the percentage by weight of % PZ PNZ and the weight percent of zeolite phase, relative to the total weight of the adsorbent.

[0023] For "adsorbent exchanged at least 90% calcium", it is meant that at least 90% of the exchangeable cationic sites of the zeolite phase is occupied by calcium cations.

[0024] The adsorbent material zeolite exchanged at least 90% calcium can be obtained and preferably is obtained according to the following protocol: the adsorbent material to exchange at calcium zeolite is introduced into a solution of calcium chloride to 0.5 mole of_{2 per liter}, to 70 °C, during 2 hours, with a ratio of 10 ml liquid to solid .g '^1. The operation is repeated n times, n being at least equal to 1, preferably at least equal to 2, preferably at least equal to 3, more preferably at least equal to 4. [0025] The solids from exchange operations n -1 and n are successively washed four times by immersion in water in an amount of 20 ml .g '^{1 to remove the excess} salt, then dried for 12 hours at 80 °C in air, before being analyzed by X-ray fluorescence, If the percentage by mass of calcium oxide the adsorbent material zeolite, between operations n -1 and n, is stable at ± 1%, said adsorbent material is zeolite considered "in its exchanged form calcium at least 90%". Optionally, are additional exchanges such as described above until a stability of the weight percentage of calcium oxide ± 1%.

[0026] The preferred cationic perform exchanges successive batch, with a large excess of calcium chloride, until the content by mass of calcium oxide the adsorbent material zeolite, determined by chemical analysis of fluorescence type X, is stable at ± 1%. The method is described further in the description.

[0027] The atomic ratio Si/Al the adsorbent material is zeolite measured by chemical analysis fluorescence elemental X, well-known technique to those skilled in the art and described further in the description.

[0028] is performed if required for exchanging assays of calcium prior to the procedure detailed above. From the microporous volume according to - measured on the adsorbent material exchanged zeolite calcium, can be calculate a volume of - global (s) zeolite (s) A, weighted PNZ.

[0029] For " ", is understood to mean the volume of the microporous zeolitic adsorbent material whose measurement technique is described further. For " ", is understood to mean the volume of the mesoporous zeolitic adsorbent material whose measurement technique is described further.

[0030] In a preferred embodiment, said at least one zeolitic adsorbent material for use in the present invention has a mesopore volume ( ) .g^{between 0.07 cm} 3 '^{1 to} 0.18 cm^{3 .g}'^1, preferably between 0.10 cm^{3 .g} '^{1 and} 0.18 cm^{3 .g}'^1, and more preferably between 0.12 cm^{3 .g} '^{1 and} 0.18 cm^{3 .g}'^1, more preferably between^{3 0.14 cm .g} '^{1 and} 0.18 cm^{3 .g}'^1, inclusive, measured on the adsorbent material exchanged at least 90% calcium.

[0031] In yet a preferred embodiment, said at least one zeolitic adsorbent material for use in the present invention has a ratio ( - ) A/micro between -0.3 and 1.0, terminals not included, preferably between 0.9 and -0.1, terminals not included, preferably between 0 and 0.9, terminals not included, more preferably between 0.2 and 0.8, terminals not included, more preferably between 0.4 and 0.8, terminals not included, preferably between 0.6 and 0.8, terminals not included, wherein the microporous volume is measured by the method of - mesoporous and is the volume determined by the Barrett-Joyner-Halenda method method (BJH), the set of measurements are made on the adsorbent material exchanged at least 90% calcium.

[0032] In yet another embodiment, said at least one zeolitic adsorbent material has a microporous volume ( , or volume of - ), expressed in cm^{3 per gram} of adsorbent material, between 0,160 cm^{3 .g} '^{1 and3 0,280 cm .g}'^1, preferably between^{3 0,180 cm .g} '^{1 and3 0,280 cm .g}'^1, preferably between^{3 0,200 cm .g} '^{1 and3 0,280 cm .g}'^1, more preferably^{3 0,220 cm .g} '^{1 and3 0,280 cm .g}'^1, measured on the adsorbent material exchanged at least 90% calcium.

[0033] The total volume of the macro-and meso-pores of the zeolite adsorbent materials for use in the present invention, measured by mercury intrusion, is advantageously between 0.15 cm^{3 .g} '^{1 and3 0.50 cm .g}'^1, preferably between 0.20 cm^{3 .g} '^{1 and3 0.40 cm .g}'^{1 and} most preferably between 0.20 cm^{3 .g} '^{1 and} 0.35 cm^{3 .g}'^1, the measurements are performed on the adsorbent material exchanged at least 90% calcium.

[0034] The volume fraction of macropores of the zeolitic adsorbent material for use in the present invention is preferably between 0.20 and 1.00 of the total volume of the macro-and meso-pores, very preferably between 0.40 and 0.80, and even more preferably between 0.45 and 0.65 inclusive, the measurements are performed on the adsorbent material zeolite exchanged at least 90% calcium.

[0035] The zeolitic adsorbent materials can be used in the present invention are either known or can be prepared from known procedures, or are novel and as such are an integral part of the present invention.

[0036] In yet a preferred embodiment, the use according to the present invention uses a zeolite adsorbent material comprising at least one mesoporous zeolite type A. For "mesoporous", is meant a zeolite which exhibits, microporosity in conjunction with the inherent in the structure of the zeolite, internal cavities nano-sized (mesoporosity), can be easily identified by observation using a transmission electron microscope (MET or "TEM" English language), as described for example in US7785563.

[0037] Specifically, said zeolite zeolite A of the adsorbent material is a mesoporous zeolite A, i.e. a zeolite having an outer surface, defined by the method t-pad later described, between 40 m .g 2 '^{1 m 2 and 400 .g}'^1, preferably between 60 m .g 2 '^{1 m .g 2 and} 200'^1, inclusive. By extension, the purposes of the present invention, a "non-mesoporous zeolite" is a zeolite optionally having an outer surface, defined by the method t-pad later described, strictly less than 40 m .g 2'^1.

[0038] In particular, the zeolite adsorbent materials can be used in the present invention include at least one zeolite type A, wherein said at least one zeolite type A has a ratio Si/Al equal to 1.00 +/- 0.05, said ratio Si/Al being measured by nuclear magnetic resonance (NMR) solid silicon 29 (^{29 NMR If}), according to the techniques well known to those skilled in the art.

[0039] The ratio Si/Al of each of the zeolites (s) present in the adsorbent is measured also by the solid NMR.

[0040] In a preferred embodiment, the zeolite A the adsorbent material is in the form of zeolite crystals whose number-average diameter, measured by a scanning electron microscope (SEM), is less than 20 pm, preferably between 0.1 and 20 pm pm, preferably between 0.1 and 10 pm, preferably between 0.5 and 10 pm pm, more preferably between 0.5 and 5 pm pm, inclusive.

[0041] In yet another preferred embodiment, said zeolitic adsorbent material comprises at least one cation selected from Group IA, IIA, NIA, IB, MB, INB of the periodic table, the trivalent ions of the lanthanide series or earths-rare, zinc ion (II), the silver ion (I), (II) the cupric ion, the chromic ion (III), the ferric ion (III), the ammonium ion and/or hydronium ion, the ions preferred are calcium ions, lithium, sodium, potassium, barium, cesium, strontium, and zinc earths-rare and more preferably the sodium ions, calcium and potassium, and mixtures thereof.

[0042] According to the present invention, the zeolite adsorbent materials described above are particularly suitable and effective in methods for the separation and/or drying gas phase, in particular in methods modulated pressure, or PSA, is of the VSA type, or VPSA, either , or TSA type and/or in type PTSA.

[0043] More specifically, the present invention relates to the use of at least one zeolitic adsorbent material, comprising at least one zeolite type A, as defined above, for drying and/or separation of gases, said more generally simply "gas separation". For gas separation, is meant drying, purification, pre-purification, removal, and other separations of one or more gaseous compounds present in a mixture of one or more gaseous compounds. More specifically, by "drying" is understood to mean the selective trapping, by adsorption with the adsorbent material zeolite, water molecules present in a gaseous medium. The term "drying" is thus included in the definition of the present disclosure the term "separation", the term "drying" to be interpreted as the separation, of a gaseous medium, of the molecules of water contained in said gaseous medium.

[0044] In a preferred aspect of the present invention, the zeolite adsorbent materials usable for drying and purification of gas are materials produces little charge loss or losses acceptable for the said uses.

[0045] It is preferred and the agglomerated zeolitic adsorbent materials and shaped made according to techniques known to those skilled in the art such as extrusion, compacting, sintering granulating dish, drum granulator, atomization and other. The proportions of agglomeration binder and zeolites implementations are typically those of the prior art, i.e. between 5 and 30 parts parts by weight of binder for 95 parts to 70 parts by weight of zeolite.

[0046] The zeolitic adsorbent material for use in the present invention, that it is in the form of beads, extrudates or other, typically has a volume average diameter, or an average length (largest dimension when not spherical), less than or equal to 7 mm, preferably between 0.05 mm and 7 mm, more preferably in the range of 0.2 mm and 5.0 mm and more preferably between 0.2 mm and 2.5 mm.

[0047] The zeolitic adsorbent materials useful in the context of the present invention have mechanical properties particularly suitable for applications to which they are intended, i.e.:

_AOE280A2AO> is a crush strength bed (REL) measured according to ASTM 7084-04 between 0.5 MPa and 3 MPa, preferably between 0.75 MPa and 2.5 MPa, material volume average diameter (D50) or a length (largest dimension when the material is not spherical), lower (e) to 1 mm, inclusive,

_AOE280A2AO> is a crush strength grain, as measured according to ASTM D 4179 (2011) and ASTM D 6175 (2013), between 0.5 and 30daN daN, preferably between 1 and 20 daN daN, material volume average diameter (D50) or a length (largest dimension when the material is not spherical), upper (e) or (e) equal to 1 mm, inclusive.

[0048] In another preferred embodiment, the use according to the present invention uses at least one zeolitic adsorbent material having a high adsorption volume capacity, i.e. a volume microporous volume expressed in cm^{3 .cm} '^{3 of adsorbent material} exchanged at least 90% calcium, said volume microporous volume is greater than 0.01 cm^{3 .cm}'^3, preferably greater than 0.02 cm^{3 .cm} '^3, preferably greater than 0.03 cm^{3 .cm}'^3, more preferably greater than 0.04 cm^{3 .cm} '^3, preferably greater than 0.05 cm^{3 .cm}'^3.

[0049] In yet another embodiment, the use according to the invention preferably carried out at least one zeolitic adsorbent material having a loss on ignition, to 950 °C measured according to the standard NF EN 196-2, between 0 and 5%, preferably between 0 and 3% by weight.

[0050] In particular, the present invention relates to the use of at least one zeolitic adsorbent material such as it has just been defined for drying the cracked gases. Is defined the term "cracked gas" with the gas obtained by cracking (for example cracking, catalytic cracking, catalytic dehydrogenation and other) of hydrocarbon feedstocks, high temperature (> 350 °C), said fillers being, for example, and for example, but not limited to, LPG, ethane, naphtha, gas oil, vacuum distillate, and other. TSA The methods are particularly suitable for these uses drying cracked gas. Particularly preferred are used for these types of applications, the adsorbent materials comprising at least one zeolite 3A, preferably mesoporous.

[0051] For these kinds of applications, is preferably a zeolitic adsorbent material whose volume mean diameter (or the greatest length) is between 0.5 mm and 7.0 mm, preferably between 1.0 mm and 7.0 mm, and more preferably between 1.5 mm and 7.0 mm, inclusive.

[0052] In another embodiment, the present invention relates to the use of at least one zeolitic adsorbent material such as it has just been defined for drying and/or separation of refrigerant fluids, in particular of HFC and HFO, such as for example and without limitation, the 1.1.1.2 tetrafluoroethane, the 2, 3, 3, 3-tetrafluoropropene, and other, such as for example those mentioned in the document W02007/144632. The TSA methods are particularly suitable for these uses drying of refrigerant fluids. Particularly preferred are used for these types of applications, the adsorbent materials comprising at least one zeolite A, preferably mesoporous, chosen from zeolites , , 5A, and mixtures thereof.

[0053] For these kinds of applications, is preferably a zeolitic adsorbent material whose volume mean diameter (or the greatest length) is between 0.3 mm and 7.0 mm, preferably between 0.8 mm and 5.0 mm, and more preferably between 1.0 mm and 4.0 mm, inclusive.

[0054] In another embodiment, the present invention relates to the use of at least one zeolitic adsorbent material such as it has just been defined for drying alcohols, and in particular ethanol, and in particular according to methods modulated pressure (PSA). Particularly preferred are used for these types of applications, the adsorbent materials comprising at least one zeolite 3A, preferably mesoporous.

[0055] For these kinds of applications, is preferably a zeolitic adsorbent material whose volume mean diameter (or the greatest length) is between 0.3 mm and 7.0 mm, preferably between 0.8 mm and 5.0 mm, and more preferably between 2.0 mm and 5.0 mm, inclusive.

[0056] In another embodiment, the present invention relates to the use of at least one zeolitic adsorbent material such as it has just been defined for drying and/or the separation of air and industrial gases. TSA The methods are particularly suitable for these uses for drying air and industrial gases. Particularly preferred are used for these types of applications, the adsorbent materials comprising at least one zeolite A, preferably mesoporous, chosen from zeolites , , 5A, and mixtures thereof.

[0057] An application especially beneficial is the separation of nitrogen and oxygen from air, according to a PSA method or VPSA, using a zeolite adsorbent material as defined above, and comprising at least one zeolite 5A, preferably mesoporous.

[0058] For these kinds of applications, is preferably a zeolitic adsorbent material whose volume mean diameter (or the greatest length) is between 0.3 mm and 7.0 mm, preferably between 0.8 mm and 5.0 mm, and more preferably between 1.0 mm and 5.0 mm, inclusive.

[0059] In another embodiment, the present invention relates to the use of at least one zeolitic adsorbent material such as it has just been defined for purification of olefins, in particular for removing impurities, and preferably for the removal of oxygen-containing impurities, and more preferably for the removal of the methanol, in particular according to adsorption processes TSA. Particularly preferred are used for these types of applications, the adsorbent materials comprising at least one zeolite A, preferably mesoporous, chosen from zeolites , , 5A and mixtures thereof, preferably from zeolites , 4A, and mixtures thereof.

[0060] For these kinds of applications, is preferably a zeolitic adsorbent material whose volume mean diameter (or the greatest length) is between 0.3 mm and 7.0 mm, preferably between 0.8 mm and 5.0 mm, and more preferably between 2.0 mm and 4.0 mm, inclusive.

[0061] In another embodiment, the present invention relates to the use of at least one zeolitic adsorbent material such as it has just been defined for drying and/or separation of the natural gas, in particular for removing impurities and preferably for removing carbon dioxide, hydrogen sulfide, mercaptans and/or light (to one or two carbon atoms: , C_{2 SH}), in particular according to adsorption processes TSA, PSA or PTSA. Particularly preferred are used for these types of applications, the adsorbent materials comprising at least one zeolite A, preferably mesoporous, chosen from zeolites , 4A and 5A, and mixtures thereof.

[0062] For these kinds of applications, is preferably a zeolitic adsorbent material whose volume mean diameter (or the greatest length) is between 0.3 mm and 7.0 mm, preferably between 0.8 mm and 5.0 mm, and more preferably between 2.0 mm and 5.0 mm, inclusive.

[0063] In another embodiment, the present invention relates to the use of at least one zeolitic adsorbent material such as it has just been defined for the separation of paraffins, preferably gas phase, in particular according to adsorption processes TSA. Particularly preferred are used for these types of applications, the adsorbent materials comprising at least one zeolite 5A, preferably mesoporous.

[0064] For these kinds of applications, is preferably a zeolitic adsorbent material whose volume mean diameter (or the greatest length) is between 0.3 mm and 7.0 mm, preferably between 0.8 mm and 5.0 mm, and more preferably between 2.0 mm and 5.0 mm, inclusive.

[0065] In another embodiment, the invention relates to the use of at least one zeolitic adsorbent material such as it has just been defined for drying and/or purification of synthesis gas. An exemplary method of purification of synthesis gas is outlined in patent EP1312406. The synthesis gas antagonism are in particular synthesis gas of hydrogen and carbon monoxide and/or hydrogen and nitrogen (synthesis gas for the production of hydrogen), and more particularly blends of hydrogen and carbon monoxide and/or hydrogen and nitrogen, these synthesis gas which may additionally contain, or be contaminated by, carbon dioxide and any one or more other impurities, such as, for example, and for example, but not limited to one or more impurities selected from nitrogen, carbon monoxide, oxygen, ammonia, hydrocarbons and oxygenated derivatives, in particular alkanes, in particular methane, alcohols, in particular methanol, and other.

[0066] The use according to the present invention is thus particularly suitable for removing nitrogen, carbon monoxide, carbon dioxide, methane, and other impurities, preferably by adsorption processes modulated pressure (PSA), for the production of hydrogen. For these kinds of applications, materials are preferred adsorbents comprising at least one zeolite A, preferably mesoporous, chosen from zeolites , 4A and 5A, and mixtures thereof.

[0067] For these kinds of applications, is preferably a zeolitic adsorbent material whose volume mean diameter (or the greatest length) is between 0.3 mm and 7 mm, preferably between 0.8 mm and 5.0 mm, and more preferably between 1.0 mm and 3.0 mm, inclusive.

[0068] In another aspect, the present invention relates to an adsorbent material zeolite having:

_AOE280A2AO> Si/Al said adsorbent, as 1.0 ≤ Si/Al < 2.0, preferably 1.0 ≤ Si/Al ≤ 1,6, more preferably 1 ≤ Si/Al ≤ 1,4,

_AOE280A2AO> a mesopore volume between 0.07 cm^{3 .g} '^{1 to} 0.18 cm^{3 .g}'^1, preferably between 0.10 cm^{3 .g} '^{1 and} 0.18 cm^{3 .g}'^1, and more preferably between 0.12 cm^{3 .g} '^{1 and} 0.18 cm^{3 .g}'^1, more preferably between^{3 0.14 cm .g} '^{1 and} 0.18 cm^{3 .g}'^1, inclusive

_AOE280A2AO> ratio ( - ) A/micro between -0.3 and 1.0, terminals not included, preferably -0.1 and 0.9, terminals not included, preferably 0 and 0.9, terminals not included, more preferably between 0.2 and 0.8, terminals not included, more preferably between 0.4 and 0.8, terminals not included, preferably between 0.6 and 0.8, terminals not included, wherein the is measured by the method of and the - BJH is measured by the method, and

_AOE280A2AO> phase content by non-zeolite (PNZ), such that 0 < PNZ ≤ 30%, preferably 3% ≤ PNZ ≤ 25%, more preferably 3% ≤ PNZ ≤ 20%, advantageously 5% ≤ PNZ ≤ 20%, more preferably 7% ≤ PNZ ≤ 18%, measured by DRX, by weight relative to the total weight of the adsorbent material ,

the set of measurements are made on the adsorbent material zeolite exchanged at least 90% calcium.

[0069] The material zeolitic adsorbent of the invention such that it is be defined is a material novel in that it results from the agglomeration, with a binder as written further, at least one mesoporous zeolite A, wherein the term "mesoporous", already previously defined designates a zeolite which exhibits, microporosity in conjunction with the inherent in the structure of the zeolite, internal cavities nano-sized (mesoporosity), can be easily identified by observation using a transmission electron microscope (MET or "TEM" English language), as described for example in US7785563.

[0070] More specifically, the adsorbent material zeolite comprises at least one mesoporous zeolite A, i.e. a zeolite having an outer surface, defined by the method t-pad later described, between 40 m .g 2 '^{1 m 2 and 400 .g}'^1, preferably between 60 m .g 2 '^{1 m .g 2 and} 200'^1, inclusive.

[0071] zeolite Further the adsorbent material according to the invention comprises at least one metal selected from potassium, sodium, calcium and mixtures of two or more of these metals, preferably two metals selected from potassium, sodium, and calcium.

[0072] These features make the zeolitic adsorbent material according to the invention particularly suitable for treatment of gas, as described above in the present specification.

[0073] The zeolitic adsorbent material may be provided in all forms known to those skilled in the art, and preferably in simple geometries, i.e. in granular forms, such as balls or rods, i.e. in the form spherical or cylindrical, respectively. Such simple shapes are particularly well-suited because they are easy to implement in particular because of their shapes and their sizes compatible with existing technologies. Furthermore, these simple shapes make the implemented methods inefficient low, the adsorbent material zeolite generating little loss of load, and having enhanced transfer properties.

[0074] The zeolitic adsorbent material according to the present invention can be prepared according to any method known to the person skilled in the art, and in particular, and preferably, from the process for the preparation of mesoporous A as described by example in W02007/043731 and agglomerating the resulting crystals with at least one organic or mineral binder, preferably mineral, preferably a binder selected from clays, or not, and in particular from kaolines, kaolinites, , , halloysite, attapulgite, sepiolites, montmorillonites, bentonites, illites and metakaolins, and mixtures of two or more of these clays, in all ratios.

[0075] Agglomeration and the shaping may be carried out according to all techniques known to those skilled in the art, such as extrusion, compacting, sintering granulating dish, drum granulator, atomization and other. The various techniques have the advantage of enabling the preparation of adsorbent materials having the sizes and previously described forms and particularly well-suited to processing of gas.

[0076] The proportions of agglomeration binder (e.g. clays, as aforesaid) and zeolite (s) implemented for the preparation are typically those of the prior art, and vary according to the content and the degree of desired PNZ of the binder. These proportions are easily computable by those skilled in the art of agglomerated specialist the synthesis of zeolite.

[0077] The agglomerates zeolitic adsorbent materials, be they in the form of beads, extrudates or other, generally have a volume average diameter, or an average length (largest dimension when they are not spherical), less than or equal to 7 mm, preferably between 0.05 mm and 7 mm, more preferably in the range of 0.2 mm and 5 mm and more preferably between 0.2 mm and 2.5 mm.

[0078] A process for the preparation of zeolitic adsorbent materials according to the invention is easily adaptable from the methods of preparing known to those skilled in the art, as already indicated, the implementation of at least one mesoporous zeolite A, which does not substantially alter these known methods, so that the preparation method is a method for easily, rapidly and economically and easily industrializable with a minimum of steps.

[0079] The adsorbent material zeolite preferably includes both of the macro-pores, meso-pores and micro-pores. For "macro-pores", is meant pores with the opening is greater than 50 nm, preferably between 50 nm and 400 nm. For "meso-pores", is meant pores with the opening is between 2 nm and 50 nm, terminals not included. For "micropores", is meant pores with the opening is less than 2 nm.

[0080] In a preferred embodiment, the adsorbent material zeolite according to the present invention has a microporous volume (volume of - ), expressed in cm^{3 per gram of material} zeolitic adsorbent, between 0,160 cm^{3 .g} '^{1 and3 0,280 cm .g}'^1, preferably between^{3 0,180 cm .g} '^{1 and3 0,280 cm .g}'^1, more preferably between^{3 0,200 cm .g} '^{1 and3 0,280 cm .g}'^1, advantageously between^{3 0,220 cm .g} '^{1 and3 0,280 cm .g}'^1, said volume being measured on a microporous material exchanged zeolitic adsorbent at least 90% calcium.

[0081] The total volume of the macro-and meso-pores of the zeolite adsorbent materials according to the invention, measured by mercury intrusion, is advantageously between 0.15 cm^{3 .g} '^{1 and3 0.50 cm .g}'^1, preferably between 0.20 cm^{3 .g} '^{1 and3 0.40 cm .g}'^{1 and} most preferably between 0.20 cm^{3 .g} '^{1 and} 0.35 cm^{3 .g}'^1, the measurements are performed on the adsorbent material exchanged at least 90% calcium.

[0082] The volume fraction of macropores of the zeolitic adsorbent material is preferably between 0.2 and 1.0 of the total volume of the macro-and meso-pores, most preferably between 0.4 and 0.8, and more preferably between 0.45 and 0.65 inclusive, the measurements are performed on the adsorbent material zeolite exchanged at least 90% calcium.

[0083] The size of the zeolite crystals type A used to prepare the zeolite adsorbent material of the invention, as well as the element size of zeolite type A in the adsorbent material zeolite, are measured by observation under a scanning electron microscope (SEM). Preferably, the average diameter of the crystals type zeolite A is between 0.1 and 20 pm pm preferably between 0.5 and 20 pm pm, and more preferably between 0.5 and 10 pm pm. Observation SEM method confirms the presence of non-zeolite phase including for example the residual binder (non-converted during optional step of ) or other amorphous phase in the agglomerates.

[0084] In a preferred embodiment, the adsorbent material zeolite according to the invention has an outer surface, as measured by nitrogen adsorption and expressed as^{2 m per gram of} adsorbent, greater than 20 m .g 2 '^1, and preferably between 20 m .g 2'^{1 and} 300 m .g 2 '^1, and particularly preferably between 30 m .g 2'^{1 and2 250 m .g} '^{1 and more preferably between} 40 m .g 2'^{1 m .g 2 and} 200 '^1, and particularly between 50 m .g 2'^{1 m .g 2 and} 200'^{1 the} measurements are performed on the adsorbent material zeolite exchanged at least 90% calcium.

[0085] In a preferred embodiment, the adsorbent material zeolite according to the invention has a volume capacity high adsorption, i.e. a volume microporous volume expressed in cm^{3 .cm} '^{3 of adsorbent material} zeolite exchanged at least 90% calcium, said volume microporous volume is greater than 0.01 cm^{3 .cm}'^3, preferably greater than 0.02 cm^{3 .cm} '^3, preferably greater than 0.03 cm^{3 .cm}'^3, more preferably greater than 0.04 cm^{3 .cm} '^3, preferably greater than 0.05 cm^{3 .cm}'^3.

[0086] In a preferred embodiment, the adsorbent material zeolite according to the invention comprises at least one mesoporous zeolite A as defined previously, said at least one zeolite having an Si/Al ratio equal to 1.00 +/- 0.05, the measurements are performed on the adsorbent material zeolite exchanged at least 90% calcium.

[0087] In yet another preferred embodiment, said zeolitic adsorbent material comprises at least one cation selected from Group IA, IIA, NIA, IB, MB, INB of the periodic table, the trivalent ions of the lanthanide series or earths-rare, zinc ion (II), the silver ion (I), (II) the cupric ion, the chromic ion (III), the ferric ion (III), the ammonium ion and/or hydronium ion, the ions preferred are calcium ions, lithium, sodium, potassium, barium, cesium, strontium, and zinc earths-rare and more preferably the sodium ions, calcium and potassium.

[0088] In yet a preferred aspect, the adsorbent material zeolite of the invention does not have structure other than the zeolite structure A (LTA). Expression "has no zeolitic structure other than the structure A", it is meant that analysis XRD (X-ray diffraction) from the adsorbent material of the present invention does not allow to detect up to 5% by weight, preferably not more than 2% by weight, inclusive, zeolitic structure other than a LTA structure, based on the total weight of the zeolite adsorbent material.

[0089] In yet another preferred embodiment, the material according to the present invention has a total volume of the macro-and meso-pores, measured by mercury intrusion, between 0.15 cm^{3 .g} '^{1 and3 0.50 cm .g}'^1, and a volume fraction of macropores between 0.2 and 1 times said total volume of the macro-and meso-pores, preferably between 0.4 and 0.8, inclusive, the measurements are performed on the adsorbent material exchanged at least 90% calcium.

[0090] The physical properties of the zeolitic adsorbent materials are evaluated by the methods known to those skilled in the art, having major of which are recalled below.

[0091] The estimate of the mean diameter by number of the crystals of zeolite type A contained in the zeolite adsorbent materials, and which are used in preparing said zeolitic adsorbent material, is carried out by observation under a scanning electron microscope (SEM).

[0092] To estimate the size of the zeolite crystals on the samples, a set of slides is carried out at a magnification of at least 5000. Measuring the diameter of at least 200 crystals using dedicated software, for example the software Smile View of the editor. The accuracy is of the order of 3%.

Granulometry zeolite adsorbents

[0093] Determining the volume average diameter (or "volume average diameter") the adsorbent material zeolite the method according to the invention is carried out by analysis of the particle size distribution of a sample of adsorbent material imaging according to ISO 13322-2:2006, using a belt conveyor to the sample to pass in front of the lens of the camera.

[0094] The volume mean diameter is then calculated from the particle size distribution by applying ISO 9276-2:2001. Herewith, is used as "volume average diameter" or "size" for the zeolitic adsorbent materials. The accuracy is of the order of 0.01 mm for the size of the adsorbent materials useful in the present invention.

[0095] Chemical analysis cell of a zeolitic adsorbent material described above, can be performed according to different analytical techniques known to those skilled in the art. Among the techniques, include the technique of chemical analysis by X-ray fluorescence as described in the standard NF EN ISO 12677:2011 to a spectrometer wavelength dispersive (WDXRF), for example of the Bruker company Tiger S8.

[0096] The fluorescence X is a spectral nondestructive technique exploiting the photoluminescence of the atoms in the field of X-rays, to establish the elemental composition of a sample. The excitation of atoms generally by an X-ray beam or by bombardment with electrons, generates specific radiation after returning to the ground state of the atom. Conventionally is obtained after calibration for each oxide a measurement uncertainty less than 0.4% by weight.

[0097] Other methods of analysis are e.g. illustrated by the methods by atomic absorption spectrometry (AAS) and atomic emission spectrometry with high-frequency plasma (ICP-AES) described in the ISO standards or NF EN 21587-3 NF EN ISO 21079-3 apparatus such as Perkin Elmer 4300DV.

[0098] The fluorescence spectrum X has the advantage of very little depend on the chemical combination of the element, which provides an accurate determination, both quantitative and qualitative. Conventionally is obtained after calibration for each oxide Si0 Al_{2 0 2 and3,} as well as the various oxides (such as those from exchangeable cations, e.g. calcium), a measurement uncertainty less than 0.4% by weight.

[0099] Therefore, the elementary chemical analyses above both verify the Si/Al ratio of the zeolite used within the zeolitic adsorbent material and the ratio Si/Al the adsorbent material zeolite. In the description of the present invention, the uncertainty in measurement of the ratio Si/Al is ± 5%. The measuring the ratio Si/Al zeolite present in the adsorbent material may also be measured by nuclear magnetic resonance spectroscopy (NMR) solid silicon.

[00100] The quality of the ion exchange is related to the number of moles of the considered in the cation exchanged zeolitic adsorbent material. More specifically, the exchange rate by a given cation is estimated by evaluating the ratio between the number of moles of said cation and the number of moles of the set of exchangeable cations. The respective amounts of each of the cations are evaluated by chemical analysis corresponding cations. For example, the rate of exchange by the calcium ions is estimated by evaluating the ratio between the total number of^{2 + cation Ca and} the total number of exchangeable cations (e.g. Ca^{2 +,} K^+, Li^+, Ba^{2 +,} Cs^+, Na^+, etc.), the amount of each of the cations being evaluated by chemical analysis suitable oxides (Na_{2 0}, CaO, K_{2 0}, BaO, Li_{2 0}, 0_Cs 2, etc). The calculation method also maintains any oxides in the residual binder zeolite of the adsorbent material. However, the amount of such oxides is considered minor relative to oxides from the cations of the exchangeable sites of the zeolites or zeolite of the adsorbent material according to the invention.

[00101] macroporous and mesoporous The volumes are measured by mercury intrusion porosimetry. Mercury intrusion A type of ® 9500 is used to analyze the distribution of the pore volume contained in the macropores and in the mesopores.

[00102] The experimental method, described in the manual procedure the apparatus referring to ASTM D4284-83, includes placing a zeolitic adsorbent material sample to be measured (of ignition loss known) previously weighed, in a cell of the porosimeter, and then, after a degassing it in advance (drain pressure of 30 pm Hg for at least 10 min), the cell to be filled with mercury at a given pressure (0.0036 MPa), and then applying pressure increasing bearing to 400 MPa to enter gradually mercury in the porous network of the sample.

[00103] Herewith, the volumes macroporous and mesoporous zeolitic adsorbent materials, expressed in cm^{3 .g} '^1, are measured by mercury intrusion and based on the mass of the sample anhydrous equivalent, i.e. the corrected mass of said material of the loss on ignition. The measurements are taken over the adsorbent material zeolite exchanged at least 90% calcium.

[00104] The crush strength of the zeolite bed adsorbent materials as described in the present invention is characterized according to ASTM 7084-04. The resistors mechanical crush grain are determined with an apparatus "Crushing grain strength" marketed by Vinci Technologies, according to ASTM D and 4179 D 6175.

[0100] Measurement of the microporous volume is estimated by conventional methods such as the measurements of the volumes of - (adsorption of liquid nitrogen at 77 K or liquid argon to 87 K).

[0101] The volume of - is determined from the measurement of the adsorption isotherm gas, such as nitrogen or argon, its liquidus temperature, according to the opening of pores of the zeolite: is selected nitrogen for the zeolite A, previously exchanged to at least 90% calcium. Prior to the adsorption, the adsorbent material is zeolite degassed between 300 °C and 450 °C for a period of between 9 and 16 hours hours, vacuum (P < 6.7,10 '^{4 Pa}). The measurement of the adsorption isotherms is then performed on apparatus 2020 of ASAP , by providing at least 35 measuring points to relative pressures of report P/P0 between 0,002 and 1. The microporous volume is determined according to and from the isotherm obtained, by applying ISO 15901-3 (2007). The volume microporous evaluated according to the equation of and is expressed in cm^{3 adsorbate} liquid per gram of material zeolitic adsorbent. The uncertainty is ±0.003 cm^{3 .g} '^1, the measurements are performed on the adsorbent material zeolite exchanged at least 90% calcium.

[0102] The volume microporous volume calculated from the microporous volume as defined above and by multiplying said microporous volume by the bulk density of said zeolitic adsorbent material. The bulk density is measured as described in the standard DI N 8948/7,6.

[0103] The loss on ignition is determined in an oxidizing atmosphere, by calcination of the sample in air at a temperature of from 950 °C ± 25 °C, as described in the standard NF EN 196-2 (April 2006). The standard deviation of measurement is less than 0.1%.

[0104] The purity zeolites in the zeolitic adsorbent materials is evaluated by X-ray diffraction analysis, known to those skilled in the art by the acronym DRX. This identification is carried out on a Bruker DRX apparatus of the mark.

[0105] The assay is capable of identifying the different zeolites present in the adsorbent material since each has a single diffractogram zeolites defined by the positioning of the diffraction peaks and by their relative intensities.

[0106] The adsorbent materials zeolite is granulated and spread and smoothed on a sample holder by simple mechanical compression.

[0107] The acquisition conditions of the diffractogram realized on apparatus D5000 Brucker are the following:

_AOE280A2AO> cu tube used to 40-30 kV mA;

_AOE280A2AO> size of the gaps (divergent, diffusion and analysis) = 0.6 mm;

_AOE280A2AO> filter: Ni;

_AOE280A2AO> device rotary sample: 15'^{1 ;}

_AOE280A2AO> measuring range: 3 < 50° < 2θ °;

_AOE280A2AO> not: 0.02 °;

_AOE280A2AO> counting time by not: 2 seconds.

[0108] Interpretation of the diffractogram obtained is carried out with the software EVA with identification zeolites using the PDF-2, release 2011.

[0109] The amount of zeolite LTA fractions, by weight, is measured by analysis by DRX, the method is also used to measure the amount of the zeolite fractions other than LTA. This analysis is performed by the mark Bruker, and the amount by weight of the zeolite fractions is evaluated by means of the software of the Bruker company.

[0110] The method of calculating said t-pad uses data isotherm ads Q = f (P/P0) and computes the microporous surface. This suggests the outer surface by the difference with the BET surface area porous surface which calculates the total m^2/ g (S BET = microporous + outer surface).

[0111] To calculate the microporous surface by the method t-pad, trace is the curve Q ads (^{3 cm .g} '¹⁾ based on t = thickness of the layer depending on the partial pressure P/P0 which typically form on a reference non-porous material (t function log (P/P0): Jura equation and applied: [13,99 / (0,034-log (P/P0⁾⁾ A 0.5], Meanwhile t comprised between 0.35 nm and 0.5 nm, can be plotted a straight line which defines a ordinate at the origin Q adsorbed for calculating the microporous surface. If the material is not microporous the right passes through 0, the measurements are performed on the adsorbent material zeolite exchanged at least 90% calcium.

[0112] Measurement of the mesoporous volume is estimated by conventional methods such as the measurements of the volumes of Barret-Joyner-Halenda method (adsorption of liquid nitrogen at 77 K).

[0113] The mesoporous volume is determined from the measurement of the adsorption isotherm gas, such as nitrogen, its liquidus temperature, according to the opening of pores of the zeolite: is selected nitrogen for the zeolite A, previously exchanged to at least 90% calcium. Prior to the adsorption, the adsorbent material is zeolite degassed between 300 °C and 450 °C for a period of between 9 and 16 hours hours, vacuum (P < 6.7,10 '^{4 Pa}). The measurement of the adsorption isotherms is then performed on apparatus 2020 of ASAP , by providing at least 35 measuring points to ratio to the relative pressures P/PO between 0,002 and 1. The mesoporous volume is determined according to Barret-Joyner-Halenda method from the isotherm obtained, by applying ISO 15901-2 (2007). The mesoporous volume evaluated according to the equation of Barret-Joyner-Halenda method is expressed in cm^{3 adsorbate} liquid per gram of material zeolitic adsorbent, the measurements are performed on the adsorbent material zeolite exchanged at least 90% calcium.