EP0265018A2 — Bonded zeolites and process for preparing them

Claim 1

Independent Claim 214 words

Process for producing zeolites bonded with oligomeric silica, comprising mixing a suspension of said Zeolite in water with an aqueous solution of oligomeric silica and alkyl-ammonium hydroxide, and submitting to quick drying the so-obtained suspension, characterized in that the percentage of zeolite in the suspension of only zeolite in water is comprised within the range of from 20% to 50% by weight, preferably of from 25% to 35% by weight, the molar ratio in the solution between the oligomeric silica and alkyl-ammonium hydroxide is comprised within the range of from 0.05 to 0.2, preferably of from 0.08 to 0.15, the ratio between the oligomeric silica and water is comprised within the range of from 0.025 to 0.0125, the ratio between the oligomeric silica and zeolite is comprised within the range of from 5:95 to 20:80, the zeolites have a diameter of the pores comprised within the range of from 5 to 13 Å, the zeolites being selected from: 1) a calcined and anhydrous zeolite, 2) a calcined, anhydrous zeolite preferably exchanged with ammonium ions, 3) a damp zeolite containing as the counter-cations, ammonium or alkyl-ammonium cations, optionally in the presence of an excess of the related hydroxides, as it is obtained by means of a hydrothermal treatment, without carrying out a final calcination thereof.

Claim 2

Dependent Claim 214 words

Process for producing zeolites bonded with oligomeric silica, comprising mixing a suspension of said Zeolite in water with an aqueous solution of oligomeric silica and alkyl-ammonium hydroxide, and submitting to quick drying the so-obtained suspension, characterized in that the percentage of zeolite in the suspension of only zeolite in water is comprised within the range of from 20% to 50% by weight, preferably of from 25% to 35% by weight, the molar ratio in the solution between the oligomeric silica and alkyl-ammonium hydroxide is comprised within the range of from 0.05 to 0.2, preferably of from 0.08 to 0.15, the ratio between the oligomeric silica and water is comprised within the range of from 0.025 to 0.0125, the ratio between the oligomeric silica and zeolite is comprised within the range of from 5:95 to 20:80, the zeolites have a diameter of the pores comprised within the range of from 5 to 13 Å, the zeolites being selected from: 1) a calcined and anhydrous zeolite, 2) a calcined, anhydrous zeolite preferably exchanged with ammonium ions, 3) a damp zeolite containing as the counter-cations, ammonium or alkyl-ammonium cations, optionally in the presence of an excess of the related hydroxides, as it is obtained by means of a hydrothermal treatment, without carrying out a final calcination thereof.

Claim 3

Dependent Claim 43 words

Process according to claim 1, wherein the zeolites are based on: A) Si, Al and B; B) Si, Al and Ti; C) Si, Ti and Fe; D) Ti and Si; E) Si and B; F) Zeolite ZSM-5; G) Zeolite ZSM-11; H) Zeolite T.

Claim 4

Dependent Claim 188 words

Process according to claim 2, characterized in that the zeolite based on Si, Al and B meets, when calcined and anhydrous, the following general formula, expressed as molar ratios: pHAlO₂ . qB₂O₃ . SiO₂ (1) with the condition that, for zeolite hydrates containing ammonium bases, if the weight of the calcined and anhydrous zeolite is called "Z", the weight of ammonium ion or of alkyl-ammonium base is called "A⁺", and the weight of water is called "H", the following relationships are met: wherein, in the general formula (1), p has a value comprised within the range of from 0.034 to 0.0050, and q has a value comprised within the range of from 0.1 to 0.005, and the H⁺ of HAlO₂ can be at least partially replaceable by cations, the zeolite of formula (1) having a powder X-ray diffraction spectrum, whose meaningful lines are reported in Table A, and an I.R. spectrum at least showing the following bands: wherein wn is the wave number, as cm⁻¹ and I rel are the relative intensities, wherein s means strong; ms = medium-strong; m = medium; mw = medium-weak; w = weak.

Claim 5

Dependent Claim 197 words

Process according to claim 2, characterized in that the zeolite based on Si, Al and Ti meets, when calcined and anhydrous, the following general formula, expressed as molar ratios: pHAlO₂ . qTiO₂ . SiO₂ (2) with the condition that, for zeolite hydrates containing ammonium bases, if the weight of the calcined and anhydrous zeolite is called "Z", the weight of ammonium ion or of alkyl-ammonium base is called "A⁺", and the weight of water is called "H", the following relationships are met: wherein in the general formula (2), p has a value larger than zero and smaller than, or equal to 0.050, and q has a value larger than zero and smaller than or equal to 0.025; and the H⁺ of HAlO₂ can be at least partially replaceable by cations, wherein the zeolite having the general formula (2) has a X-ray diffraction spectrum of the powders, whose most meaningful lines are reported in following Table B, and an I.R. spectrum at least showing the following bands: wherein wn is the wave number, as cm⁻¹ and I rel are the relative intensities, wherein s means strong; ms = medium-strong; m = medium; mw = medium-weak; w = weak.

Claim 6

Dependent Claim 108 words

Process according to claim 2, characterized in that the zeolite based on Si and Ti meets, when calcined and anhydrous, the following general formula, expressed as molar ratios: xTiO₂ . (1-x)SiO₂ (3) with the condition that, for zeolite hydrates containing ammonium bases, if the weight of the calcined and anhydrous zeolite is called "Z", the weight of ammonium ion or of alkyl-ammonium base is called "A⁺", and the weight of water is called "H", the following relationships are met: wherein in the general formula (3), x is comprised within the range of from 0.0005 to 0.04, preferably of from 0.01 to 0.025, according to US patent No. 4,410,501.

Claim 7

Dependent Claim 178 words

Process according to claim 2, characterized in that the zeolite based on Si, Ti and Fe meets, when calcined and anhydrous, the general formula, expressed as molar ratios: pHFeO₂ . qTiO₂ . SiO₂ (4) with the condition that, for zeolite hydrates containing ammonium bases, if the weight of the calcined and anhydrous zeolite is called "Z", the weight of ammonium ion or of alkyl-ammonium base is called "A⁺", and the weight of water is called "H", the following relationships are met: wherein in the general formula (4), p has a value larger than zero and smaller than, or equal to 0.050, and q has a value larger than zero and smaller than or equal to 0.025; and the H⁺ of HFeO₂ can be at least partially replaceable by cations, wherein the zeolite having the general formula (4) shows an I.R. spectrum at least showing the following bands: wherein wn is the wave number, as cm⁻¹ and I rel are the relative intensities, wherein s means strong; ms = medium-strong; m = medium; mw = medium-weak; w = weak.

Claim 8

Dependent Claim 63 words

Process according to claim 1, characterized in that the solution of silica and alkyl-ammonium hydroxide is prepared by hydrolysing in liquid phase a tetraalkyl-orthosilicate in an aqueous solution of alkyl-ammonium hydroxide at a temperature comprised within the range of from 2°C to 120°C, preferably of from 50 to 60°C and for a time comprised within the range of from 0.2 to 24 hours.

Claim 9

Dependent Claim 10 words

Process according to claim 7, wherein the tetraalkyl-orthosilicate is tetraethyl-orthosilicate.

Claim 10

Dependent Claim 27 words

Process according to claim 1, wherein the alkyl-ammonium hydroxide has its alkyls with a number of carbon atoms comprised within the range of from 1 to 5.

Claim 11

Dependent Claim 9 words

Process according to claim 9, wherein alkyl-ammonium is tetrapropyl-ammonium.

Claim 12

Dependent Claim 138 words

Zeolite bonded with oligomeric silica, characterized in that the crystals of zeolite A, or of zeolite B, or of zeolite C, or of zeolite D, or of zeolite E, or of zeolite F, or of zeolite G, or of zeolite H are in the form of microspheres having a molar ratio of the oligomeric silica to zeolite A, or to zeolite B, or to zeolite C, or to zeolite D, or to zeolite E, or to zeolite F, or to zeolite G, or to zeolite H comprised within the range of from 5:95 to 20:80, the crystals of zeolite A, or of zeolite B, or of zeolite C, or of zeolite D, or of zeolite E, or of zeolite F, or of zeolite G, or of zeolite H are caged with one another by means of Si-O-Si bridges.

Claim 13

Dependent Claim 138 words

Zeolite bonded with oligomeric silica, characterized in that the crystals of zeolite A, or of zeolite B, or of zeolite C, or of zeolite D, or of zeolite E, or of zeolite F, or of zeolite G, or of zeolite H are in the form of microspheres having a molar ratio of the oligomeric silica to zeolite A, or to zeolite B, or to zeolite C, or to zeolite D, or to zeolite E, or to zeolite F, or to zeolite G, or to zeolite H comprised within the range of from 5:95 to 20:80, the crystals of zeolite A, or of zeolite B, or of zeolite C, or of zeolite D, or of zeolite E, or of zeolite F, or of zeolite G, or of zeolite H are caged with one another by means of Si-O-Si bridges.

Claim 14

Dependent Claim 22 words

Bonded silica according to claim 11, wherein the microspheres have a diameter comprised within the range of from 5 to 1,000 µm.

Bonded zeolites and process for preparing them

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