Synthesis of high-purity FER framework IZM-8 zeolite

Abstract

The present invention relates to a novel method for preparing FER framework IZM-8 zeolite, which allows the synthesis of FER framework IZM-8 zeolite by converting / converting FAU framework zeolite under hydrothermal conditions. In particular, this novel method allows the synthesis of FER framework IZM-8 zeolite starting from FAU framework zeolite, which is used as a source of silicon and aluminum, and N-ethyl-N-(3,3,5-trimethylcyclohexyl)pyrrolidinium hydroxide, a specific organic or structuring molecule containing a quaternary ammonium functional group. The FER framework IZM-8 zeolite obtained by the method of the present invention can be advantageously used as a catalyst, adsorbent, or separation agent.

Description

[Technical Field]

[0001] The present invention relates to a novel method for preparing FER framework-type IZM-8 zeolite. This novel method allows for the synthesis of FER framework-type IZM-8 zeolite by converting FAU framework-type zeolite under hydrothermal conditions. In particular, this novel method allows for the synthesis of FER framework-type IZM-8 zeolite starting from FAU framework-type zeolite, which is used as a source of silicon and aluminum, and N-ethyl-N-(3,3,5-trimethylcyclohexyl)pyrrolidinium hydroxide, a specific structural or organic molecule containing quaternary ammonium functional groups. The FER framework-type IZM-8 zeolite obtained by the method of the present invention can be advantageously used as a catalyst, adsorbent, or separation agent. [Background technology]

[0002] Crystalline microporous materials, such as zeolites and silicoaluminophosphates, are solids widely used in the petroleum industry as catalysts, catalyst supports, adsorbents, and separation agents. While many microporous crystalline structures have been discovered, the petroleum refining and petrochemical industries are constantly seeking new zeolite structures with unique properties for applications such as gas purification or separation, and carbon-based material conversion.

[0003] The FER framework type includes the following zeolites: ZSM-35, NU-23, FU-9, and ISI-6. The FER framework type has a two-dimensional 10-MR channel system with a pore size of 0.42 × 0.54 nm, interconnected by an 8-MR channel system with a pore size of 0.35 × 0.48 nm (Exxon Mobil Oil Corp. US4107195, J. Li et al. Catl. Lett., 20, (1993) 345).

[0004] FER framework zeolites have been synthesized using nitrogen-containing organic species such as pyrrolidine (J. Perez-Pariente et al. Micropor. Mesopor. Mat., 129, (2010) 164; LY Xu et al. Micropor. Mesopor. Mat., 240, (2017) 189), pyridine in the presence of NaF (T. Okubo et al. Micropor. Mesopor. Mat., 181, (2013) 154), and cyclohexylamine (W. Qingxia et al. Chinese Journal of Catalysis, 24, (2003) 531).

[0005] V. Valtchev et al. (Micropor. Mesopor. Mat., 200, (2014) 334) prepared FER framework zeolites in the presence of Na-ethylenediamine, Na-K, and Na-pyrrolidine to investigate the effect of mixing two structuring agents on the crystallization time and morphology of the resulting materials.

[0006] Examples include the use of organic compounds such as tetrahydrofuran as structuring agents to prepare FER framework zeolites (YC Long et al. Chem. Commun, 19, (2000), 1893; YC Long et al. Micropor. Mesopor. Mat., 119, (2009) 60).

[0007] J. Pérez-Pariente et al. (Chem. Mater. 19, 23 (2007), 5617; Catal. Today, 179, (2012) 16) prepared FER framework zeolites in the absence of inorganic cations using a mixture of organic cations, tetramethylammonium and benzylmethylpyrrolidinium, in a fluorinated medium as a structuring agent. Summary of the Invention

[0008] Surprisingly, the present applicant has developed a method for preparing FER framework zeolite from FAU framework zeolite in the presence of a specific structuring agent, which makes it possible to easily and reproducibly obtain high- or very-high-purity FER framework zeolite, designated IZM-8, with an SiO2 / Al2O3 ratio in the range of 15 to 30, preferably 10 to 25. The method for preparing FER framework IZM-8 zeolite allows the synthesis of FER framework IZM-8 zeolite by converting / transforming FAU framework zeolite under hydrothermal conditions. In particular, this new method allows the synthesis of FER framework IZM-8 zeolite starting from FAU framework zeolite, which is used as a source of silicon and aluminum, and N-ethyl-N-(3,3,5-trimethylcyclohexyl)pyrrolidinium hydroxide, a specific structuring or organic molecule containing quaternary ammonium groups. The FER framework type IZM-8 zeolite obtained according to the process of the invention is advantageously used as a catalyst, adsorbent or separation agent.

[0009] More particularly, the present invention relates to a method for producing a high-purity FER framework-type IZM-8 zeolite, which comprises at least the following steps: i) in an aqueous medium, FAU framework zeolite as a source of silicon in the oxide form SiO2 and aluminum in the oxide form Al2O3, a nitrogen-containing organic compound R, where R is N-ethyl-N-(3,3,5-trimethylcyclohexyl)pyrrolidinium hydroxide; at least one alkali metal and / or alkaline earth metal M of valence n, where n is an integer greater than or equal to 1; and Optionally, at least one trivalent element source in the oxide form Y2O3 wherein the mixture has the following molar composition: (SiO 2(FAU) ) / (AlO 3(FAU) +Y2O3) is in the range of 6 to 200, preferably in the range of 6 to 100, HO / (SiO 2(FAU) ) is in the range of 1 to 16, preferably in the range of 5 to 14, R / (SiO 2(FAU) ) is in the range of 0.01 to 0.5, preferably in the range of 0.04 to 0.3, M 2 / n O / (SiO 2(FAU) ) is in the range of 0.005 to 0.45, preferably in the range of 0.05 to 0.2, where Y is one or more trivalent elements selected from the group consisting of aluminum, boron, and gallium, and SiO 2(FAU) is the amount of SiO2 provided by the FAU zeolite, and Al2O 3(FAU) is the amount of Al2O3 provided by the FAU zeolite, M is one or more alkali metals and / or alkaline earth metals selected from lithium, sodium, potassium, calcium, magnesium, and mixtures of at least two of these metals; mixing the mixture until a homogeneous precursor gel is obtained; ii) aging the homogeneous precursor gel obtained at the end of step i), with or without stirring, at a temperature ranging from 15°C to 100°C for a period ranging from 10 minutes to 48 hours; iii) hydrothermally treating the precursor gel obtained at the end of step ii) at a temperature ranging from 120°C to 220°C for a period ranging from 12 hours to 7 days inclusive, until the FER-framework IZM-8 zeolite is formed.

[0010] Preferably, M is sodium. Preferably, the source of at least one alkali metal M is sodium hydroxide. Y may be aluminum.

[0011] Seed crystals of an FER framework-type zeolite can be added to the reaction mixture of step i) or to the homogeneous precursor gel of step ii) in an amount ranging from 0.01% to 10% of the total mass of the source of elements Si and Al in anhydrous form used in the reaction mixture, the seed crystals being exclusive of the total mass of the source of elements Si and Al.

[0012] The maturation in step ii) can be carried out at ambient temperature with stirring for a period ranging from 6 to 24 hours inclusive.

[0013] The hydrothermal treatment of step iii) can be carried out under autogenous reaction pressure. The hydrothermal treatment in step iii) can be carried out at a temperature in the range of 140°C to 195°C.

[0014] After carrying out step iii), the solid phase formed from the FER-framework IZM-8 zeolite obtained at the end of step iii) is filtered, washed and dried at a temperature ranging from 20°C to 150°C, preferably from 60°C to 100°C, for a period ranging from 5 to 24 hours to obtain a dried zeolite.

[0015] The dried zeolite may then be calcined at a temperature ranging from 450° C. to 700° C. for a period ranging from 2 to 20 hours, with the temperature optionally being gradually increased prior to the calcination.

[0016] The present invention also relates to an FER framework IZM-8 zeolite having a purity of at least 90% by weight, preferably more than 95% by weight, and an SiO2 / Al2O3 ratio in the range of 15 to 30 (both inclusive), preferably in the range of 10 to 25 (both inclusive), which is obtainable by any of the aforementioned various production processes.

[0017] The present invention also relates to a FER framework IZM-8 zeolite having a purity of 90% by weight or more, preferably more than 95% by weight, an SiO2 / Al2O3 ratio in the range of 15 to 30, inclusive, preferably in the range of 10 to 25, inclusive, calcined according to the procedure described above, and having a d measured by X-ray diffraction pattern. hkl The mean values ​​and relative intensities of are as follows, where VS = very strong; S = strong; m = moderate; mw = slightly weak; w = weak; vw = very weak, relative intensity I rel is given in relation to a relative intensity scale in which the most intense line of the X-ray diffraction pattern is assigned a value of 100: for zeolites vw<15; 15≦30; 30≦mw<50; 50≦m<65; 65≦S<85; VS≧85.

[0018] [Table 1]

[0019] The IZM-8 zeolite has a particle size of 0.122 to 0.136 cm 3 / g and micropore volume in the range of 325~400m 2 / g BET specific surface area.

[0020] Description of the embodiment The subject of the present invention is a novel method for producing IZM-8 zeolite of the FER framework type by converting or transforming FAU framework zeolite under hydrothermal conditions in the presence of a specific structuring agent or nitrogen-containing organic compound, N-ethyl-N-(3,3,5-trimethylcyclohexyl)pyrrolidinium hydroxide.

[0021] In particular, the applicant has discovered that mixing a specific structuring agent or nitrogen-containing organic compound, N-ethyl-N-(3,3,5-trimethylcyclohexyl)pyrrolidinium hydroxide, with an FAU framework-type zeolite used as a source of silicon and aluminum, with or without the addition of at least one source of at least one trivalent element Y selected from aluminum, boron, or gallium, results in the formation of a mixture known as a precursor gel for FER framework-type IZM-8 zeolite, in which the molar ratio of the total amount expressed as oxides of tetravalent elements to the total amount expressed as oxides of trivalent elements is in the range of 8 to 13. The total amount of tetravalent elements represents the content of SiO2 derived from the FAU zeolite, and the total amount of trivalent elements represents the sum of the content of Al2O3 derived from the FAU zeolite and the content of YO2O3 derived from at least one additional source of the oxide YO3, if added.

[0022] Gel maturation followed by hydrothermal treatment allows the production of high- or very high-purity FER framework IZM-8 zeolites.

[0023] The crystalline solid consisting of FER framework IZM-8 zeolite obtained at the end of the preparation process is generally, and very preferentially, free from any other crystalline or amorphous phases.

[0024] The purity of the obtained FER framework IZM-8 zeolite is at least 90% by weight, preferably at least 95% by weight, very preferably at least 97% by weight, more preferably at least 98% by weight, even more preferably at least 99% by weight, or even at least 99.8% by weight, based on the total mass of the obtained crystalline solid material.

[0025] Advantageously, the FER framework type IZM-8 zeolite obtained has an SiO2 / Al2O3 ratio in the range 15-30, preferably in the range 10-25. Drawing list [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 shows the chemical formula of the nitrogen-containing organic compound R, which is the structuring agent used in the synthesis method according to the invention. [Figure 2] FIG. 2 shows the X-ray diffraction pattern of the FER framework IZM-8 zeolite obtained according to Example 3. [Figure 3] FIG. 3 shows the X-ray diffraction pattern of the FER framework IZM-8 zeolite obtained according to Example 4. [Figure 4] FIG. 4 shows the X-ray diffraction pattern of the MOR framework zeolite obtained according to Example 6. DETAILED DESCRIPTION OF THE INVENTION

[0027] Other features and advantages of the method for synthesizing IZM-8 zeolite according to the invention, the catalyst according to the invention and the use according to the invention will become apparent from the description of non-limiting exemplary embodiments given below with reference to the accompanying drawings.

[0028] Detailed Description of the Invention More precisely, the subject of the present invention is a novel process for the preparation of FER framework type IZM-8 zeolites, comprising at least the following steps: i) in an aqueous medium, FAU framework zeolite, Nitrogen-containing organic compounds R, also known as specific structuring agents, N-ethyl-N-(3,3,5-trimethylcyclohexyl)pyrrolidinium hydroxide, at least one alkali metal and / or alkaline earth metal M of valence n, where n is an integer greater than or equal to 1; and Optionally, at least one source of a trivalent element in oxide form Y2O3 is mixed in, The mixture has the following molar composition: (SiO 2(FAU) ) / (AlO 3(FAU) +Y2O3) is in the range of 6 to 200, preferably in the range of 6 to 100, H2O / (SiO2( FAU) ) is in the range of 1 to 16, preferably in the range of 5 to 14, R / (SiO 2(FAU) ) is in the range of 0.01 to 0.5, preferably in the range of 0.04 to 0.3, M 2 / n O / (SiO 2(FAU) ) is in the range of 0.005 to 0.45, preferably in the range of 0.05 to 0.2, where Y is one or more trivalent elements selected from the group consisting of aluminum, boron, and gallium; preferably, Y is aluminum; and SiO 2(FAU) is the amount of SiO2 provided by the FAU zeolite, and Al2O 3(FAU) is the amount of Al2O3 provided by the FAU zeolite; and M is one or more alkali metals and / or alkaline earth metals selected from lithium, sodium, potassium, calcium, magnesium, and mixtures of at least two of these metals; highly preferably, M is sodium; mixing until a homogeneous mixture is obtained, called a precursor gel; wherein step i) is preferably carried out for a period ranging from 5 to 15 minutes; ii) aging the precursor gel of step i), with or without stirring, at a temperature ranging from 15°C to 100°C for a period ranging from 10 minutes to 48 hours, preferably from 6 hours to 24 hours; iii) hydrothermally treating the precursor gel obtained at the end of step ii) at a temperature ranging from 120°C to 220°C for a period ranging from 12 hours to 7 days until the FER-framework IZM-8 zeolite is formed.

[0029] Thus, one advantage of the present invention is that it provides a new method for forming high or very high purity FER framework zeolites from FAU framework zeolites, which method is carried out in the presence of a specific organic structuring agent, N-ethyl-N-(3,3,5-trimethylcyclohexyl)pyrrolidinium hydroxide.

[0030] The starting FAU framework zeolite preferably has a SiO / AlO molar ratio of 6.00 or greater and can be obtained by any method known to those skilled in the art, such as by steaming and acid washing an FAU framework zeolite having a SiO / AlO molar ratio of less than 6.00. Sources of FAU having a SiO / AlO ratio of 6.00 or greater include commercially available zeolites CBV712, CBV720, CBV760, and CBV780 from Zeolyst, and commercially available zeolites HSZ-350HUA, HSZ-360HUA, and HSZ-385HUA from Tosoh.

[0031] In the first embodiment, SiO 2 is used as a source of silicon and aluminum elements. 2(FAU) / AlO 3(FAU) An FAU framework zeolite having a molar ratio of 6.00 or more, preferably in the range of 6.00 to 200, more preferably in the range of 6.00 to 100, can be added to the reaction mixture for carrying out step (i).

[0032] In another embodiment, a FAU framework-type zeolite and at least one trivalent element source in oxide form Y2O3 can be used in step i), the composition of the reaction mixture being (SiO 2(FAU) ) / (AlO 3(FAU) +Y2O3) is set to be in the range of 6 to 200, preferably in the range of 6 to 100.

[0033] In a preferred variant of this embodiment, when Y is aluminum and in step i) an FAU framework zeolite and at least one other aluminum source in oxide form Al2O3 are used, the composition of the reaction mixture is: (SiO 2(FAU) ) / (AlO 3(FAU) +Al2O3) is set to be in the range of 6 to 200, preferably in the range of 6 to 100, which means that the composition of the reaction mixture takes into account the amount of aluminum oxide provided by the FAU zeolite and the amount of aluminum oxide provided by other aluminum sources.

[0034] In the present invention, R is the nitrogen-containing organic compound N-ethyl-N-(3,3,5-trimethylcyclohexyl)pyrrolidinium hydroxide, which compound is added as organic structuring agent to the reaction mixture for carrying out step i).

[0035] In the present invention, in the reaction mixture of step i) at least one source of at least one alkali metal and / or alkaline earth metal M of valence n is used, where n is an integer greater than or equal to 1, and M is preferably selected from lithium, potassium, sodium, magnesium and calcium, and mixtures of at least two of these metals. Highly preferably, M may be sodium.

[0036] Preferably, the source of at least one alkali metal and / or alkaline earth metal M may be sodium hydroxide.

[0037] According to the invention, in the mixture of step i) at least one additional source of oxide Y2O3 can be used, where Y is one or more trivalent elements selected from the group consisting of the following elements: aluminum, boron, gallium. Preferably, Y can be aluminum.

[0038] As a source of aluminum, preferably aluminum hydroxide or aluminum salts such as chlorides, nitrates or sulfates, sodium aluminate, aluminum alkoxides, or alumina itself, preferably in a hydrated or hydratable form, such as colloidal alumina, pseudoboehmite, γ-alumina or α- or β-alumina trihydrate, can be used. Mixtures of these sources can also be used. Highly preferably, the additional source of oxide YO is sodium aluminate.

[0039] Step i) of the process according to the invention consists in preparing an aqueous reaction mixture comprising an FAU framework-type zeolite, optionally a source of oxide YO, at least one nitrogen-containing organic compound R, where R is N-ethyl-N-(3,3,5-trimethylcyclohexyl)pyrrolidinium hydroxide, in the presence of at least one source of one or more alkali metals and / or alkaline earth metals, to obtain a precursor gel of the FER framework-type zeolite. The amounts of said reagents in the reaction mixture are adjusted as described above so that the gel has a composition which allows the crystallization of the FER framework-type IZM-8 zeolite.

[0040] In order to reduce the time required for the formation of FER framework-type zeolite crystals and / or the overall crystallization time, it may be advantageous to add seed crystals of FER framework-type zeolite to the reaction mixture during step i) of the method of the present invention or to the precursor gel during step ii), preferably at the end of the maturation step ii). The seed crystals also promote the formation of the FER framework-type IZM-8 zeolite while suppressing the formation of impurities. Such seed crystals comprise crystalline solids, in particular crystals of FER framework-type zeolite. The seed crystals are usually added in a proportion ranging from 0.01% to 10% of the total mass of the sources of tetravalent and trivalent elements used in the reaction mixture, and the seed crystals are not included in the total mass of the sources of tetravalent and trivalent elements. These seed crystals are useful for determining the composition of the reaction mixture and / or the composition of the gel as defined above, i.e., for determining the various molar ratios of the composition of the reaction mixture, in particular (SiO 2(FAU) ) / (AlO 3(FAU) +Y2O3), H2O / (SiO 2(FAU) ), R / (SiO 2(FAU) ), M 2 / n O / (SiO 2(FAU) ) will not be taken into consideration in determining

[0041] The mixing step i) is carried out with stirring at low or high shear rates, preferably by any system known to those skilled in the art, until a homogeneous mixture is obtained, preferably for a period ranging from 5 minutes to 15 minutes. At the end of step i), a homogeneous precursor gel is obtained.

[0042] The step ii) of aging the reaction mixture prior to the hydrothermal crystallization in step iii) of the method of the present invention allows for control of the crystal size of the FER framework-type IZM-8 zeolite. This aging also suppresses the formation of impurities and promotes the formation of the FER framework-type zeolite. The aging of the reaction mixture in step ii) of the method of the present invention can be carried out at ambient temperature (generally taken to be equal to 20°C) or at a temperature in the range of 15°C to 100°C, with or without stirring, for a period in the range of 10 minutes to 48 hours, preferably in the range of 6 to 24 hours.

[0043] According to step ii) of the method of the present invention, the precursor gel obtained at the end of step ii) is hydrothermally treated at a temperature ranging from 120°C to 220°C for a period ranging from 12 hours to 7 days until said FER-framework IZM-8 zeolite is formed.

[0044] The precursor gel is advantageously subjected to hydrothermal conditions under autogenous reaction pressure, preferably at a temperature in the range of 120°C to 220°C, more preferably in the range of 140°C to 195°C, optionally with the addition of a gas, for example nitrogen, until the FER framework type IZM-8 zeolite is completely crystallized.

[0045] The time required for crystallization is in the range of 12 hours to 7 days, preferably in the range of 12 hours to 6 days, and more preferably in the range of 12 hours to 3 days.

[0046] The reaction is usually carried out with or without stirring, preferably with stirring. The stirring device that can be used may be any device known to those skilled in the art, such as an inclined blade with counter blades, a stirring turbomixer, or an Archimedes screw.

[0047] After carrying out step iii) of the production method according to the present invention, the solid phase formed from the FER-framework IZM-8 zeolite at the end of the reaction can be preferably filtered, washed, and then dried. Drying can usually be carried out at a temperature in the range of 20°C to 120°C, preferably in the range of 60°C to 100°C, for a period in the range of 5 hours to 24 hours.

[0048] The dried zeolite can then preferably be calcined. The calcined FER framework IZM-8 zeolite is usually analyzed by X-ray diffraction, which technique also makes it possible to determine the purity of the zeolite obtained by the process of the invention.

[0049] Highly advantageously, the process of the present invention results in the formation of a FER framework-type zeolite that is free of other crystalline or amorphous phases. After the drying step, the FER framework-type IZM-8 zeolite is ready for subsequent steps such as calcination and ion exchange. These steps can be carried out by any conventional method known to those skilled in the art.

[0050] The loss on ignition of the FER-framework IZM-8 zeolite obtained after drying and before calcination is usually in the range of 5% to 15% by weight. In the present invention, the loss on ignition (LOI) refers to the ratio of the mass lost by the solid compound, i.e., the IZM-8 zeolite preferably produced in the present invention, during heat treatment at 1000°C for 2 hours in a muffle furnace to the mass of the initial solid compound, i.e., the mass of the IZM-8 zeolite preferably dried in the present invention. This loss on ignition generally corresponds to the loss of solvent (e.g., water), but also to the removal of organic compounds contained in the solid.

[0051] The FER framework IZM-8 zeolite obtained by the process of the invention can be advantageously calcined. The calcination step can be carried out at a temperature preferably ranging from 450°C to 700°C for a period ranging from 2 hours to 20 hours.

[0052] The FER framework IZM-8 zeolite obtained at the end of the calcination step is free of any organic species, and in particular free of organic structuring agents R.

[0053] At the end of the calcination step, the solid obtained by the method of the present invention can be confirmed by X-ray diffraction to be a FER framework zeolite. The purity of the FER framework IZM-8 zeolite thus obtained is 90% by weight or more, preferably 95% by weight or more, very preferably 97% by weight or more, more preferably 98% by weight or more, even more preferably 99% by weight or more, or even 99.8% by weight or more, based on the total mass of the crystalline solid material obtained.

[0054] The resulting solid has an X-ray diffraction pattern that includes at least the diffraction lines set forth in Table 1. Preferably, the X-ray diffraction pattern does not include any diffraction lines having significant intensities (i.e., intensities greater than about three times the background noise) other than those set forth in Table 1.

[0055] This diffraction pattern is from copper K α1 The crystal structure is obtained by radiation crystallography using a conventional powder diffractometer with radiation (λ = 1.5406 Å). Based on the position of the diffraction peaks, expressed as the angle 2θ, the lattice spacing d characteristic of the sample is calculated using Bragg's law. hkl is calculated. d hkl Measurement error Δ(d hkl ) is calculated by Bragg's law as a function of the absolute error Δ(2θ) assigned to the measurement of 2θ. The absolute error Δ(2θ) is generally accepted to be ±0.02°. hkl The relative intensity I assigned to each value of rel are measured according to the height of the corresponding diffraction peak. The X-ray diffraction pattern of the crystalline solid of the FER framework type according to the present invention has at least the d hkl Table 1 includes diffraction lines corresponding to values ​​of d measured in the X-ray diffraction patterns of calcined FER framework crystalline solids. hkl The average values ​​and relative intensities of the d shown in Table 1 are shown. hkl It consists of lines at least at values ​​of dhkl The value column shows the average lattice spacing in angstroms (Å). Each of these values ​​has a measurement error Δ(d hkl ) must be assigned.

[0056] [Table 2]

[0057] where VS = very strong; S = strong; m = moderate; mw = slightly weak; w = weak; vw = very weak. Relative Intensity I rel is given in relation to a relative intensity scale in which the most intense line of the X-ray diffraction pattern is assigned a value of 100: vw<15; 15≦w<30; 30≦mw<50; 50≦m<65; 65≦S<85; VS≧85.

[0058] X-ray fluorescence (XRF) spectroscopy is a chemical analysis technique that utilizes the fluorescence of X-rays, a physical property of matter. This method allows for precise and reproducible analysis of most chemical elements, starting with beryllium (Be), in concentrations ranging from a few ppm to 100%. X-rays are used to excite the atoms in a sample, resulting in the emission of X-rays with energies specific to each element. The intensity and energy of these X-rays are measured to determine the element concentrations in a sample.

[0059] The specific surface area is calculated using the Brunauer-Emmett-Teller (BET) method (Brunauer, S. et al., Journal of the American Chemical Society 1938, 60 (2), 309-319), and the micropore volume is calculated using a t-plot (Storck et al. Applied Catalysis A: General 1998, 174 (1-2), 137-146).

[0060] The calcined IZM-8 zeolite according to the invention advantageously has a micropore volume of between 0.122 and 0.136 cm 3 / g, and the BET specific surface area is advantageously in the range of 325 to 400 m 2 / g range.

[0061] It is also advantageous to obtain the proton form of the FER framework-type IZM-8 zeolite obtained by the method of the present invention. This proton form can be obtained by ion exchange with an acid, in particular a strong mineral acid such as hydrochloric acid, sulfuric acid, or nitric acid, or with compounds such as ammonium chloride, ammonium sulfate, or ammonium nitrate. The ion exchange can be carried out by suspending the FER framework-type IZM-8 zeolite in an ion exchange solution one or more times. The zeolite can be calcined before or after the ion exchange, or between two ion exchange steps. Calcining the zeolite before the ion exchange is preferred, as it removes organic materials contained in the zeolite pores, thereby facilitating the ion exchange.

[0062] The FER framework IZM-8 zeolite obtained by the process of the present invention can be used, after ion exchange, as an acidic solid for catalytic purposes in the refining and petrochemical sectors, as an adsorbent and as a molecular sieve. [Example]

[0063] Example 1: Preparation of N-ethyl-N-(3,3,5-trimethylcyclohexyl)pyrrolidinium dihydroxide (Structuring Agent R) Synthesis of enamine: N-(3,3,5-trimethylcyclohex-1-enyl)pyrrolidine + N-(3,5,5-trimethylcyclohex-1-enyl)pyrrolidine: 42.1 g (0.3 M) of 3,3,5-trimethylcyclohexanone and 64 g (0.9 M) of pyrrolidine were placed in a 1000 mL round-bottom flask and 500 mL of cyclohexane was added to dissolve the reactants. The reaction was stirred at 450 rpm, and then 65 g (0.54 M) of magnesium sulfate was added. The reaction was refluxed for 120 hours. After returning to ambient temperature, the resulting suspension was filtered through a porosity 3 frit. The resulting solid was washed on the frit with two 50 mL portions of cyclohexane. The cyclohexane was removed on a rotary evaporator to give 54 g (93% yield) of product. 1 H and 13 The C-NMR spectrum was consistent with the expected product structure (specifically, the enamine ethylenic protons were observed at 4.05 and 4.11 ppm, and the ethylenic carbons at 99.62, 105.62, 141.36, and 142.11 ppm).

[0064] Synthesis of N-(3,3,5-trimethylcyclohexyl)pyrrolidine: 25.1 g (0.13 M) of the enamine is placed in a 100 mL round-bottom flask and 13 g (0.282 M) of formic acid is added with stirring at 300 rpm. The reaction is heated to 80°C for 3 hours. After returning to ambient temperature, 20 g of 10% sulfuric acid is added with stirring at 800 rpm, and the reaction is allowed to continue stirring at ambient temperature overnight.

[0065] Add 50 g of 20% sodium hydroxide solution and 150 ml of ethyl ether to obtain a two-phase medium with an aqueous pH > 10. After decanting the organic phase, extract the aqueous phase twice with 100 ml of ethyl ether. Combine the organic phases and dry them over magnesium sulfate. Filter the magnesium sulfate and remove the ethyl ether on a rotary evaporator to obtain 7, 22.9 g (yield: 90%) of product. 1 H and 13 The C-NMR spectrum was consistent with the expected product structure (in particular, the disappearance of the ethylenic protons and carbons, and the β-protons relative to the nitrogen observed at 2.29, 2.48, and 2.61 ppm).

[0066] Synthesis of N-ethyl-N-(3,3,5-trimethylcyclohexyl)pyrrolidinium iodide Place 19.5 g (0.1 M) of N-(3,3,5-trimethylcyclohexyl)pyrrolidine in a 500 mL round-bottom flask and add 250 mL of acetonitrile to dissolve the N-(3,3,5-trimethylcyclohexyl)pyrrolidine. Heat the reaction mixture to 60 °C while stirring at 200 rpm (bar magnet), then add 62.3 g (0.4 M) of ethyl iodide over 22 minutes. Hold the reaction mixture at 60 °C for 24 hours. Evaporation of acetonitrile gave 34.9 g (99.5% crude yield) of crude product.

[0067] The solid is dissolved in 290 ml of acetone. After heating to reflux to obtain a solution, 140 ml of ethyl ether are added, and the precipitation of a white solid is observed. After returning to ambient temperature, the suspension obtained is filtered through a frit with a porosity of 3. The solid obtained is washed on the frit with 100 ml of a 1 / 2 mixture of ethyl ether / acetone. This gives 29 g of moist solid, which is then dried overnight in a ventilated oven at 45° C. until a constant weight is reached, giving 23.7 g (68% yield) of product.

[0068] Since there are two diastereomers, 1 H and 13 The C-NMR spectrum was complex but consistent with the expected structure of the product (protons β to nitrogen were observed at 3.38 and 3.58 ppm). The product was considered to be very pure, with no signals observed that could correspond to the presence of impurities.

[0069] Synthesis of N-ethyl-N-(3,3,5-trimethylcyclohexyl)pyrrolidinium hydroxide To a 250 mL Teflon beaker containing 23.4 g (0.07 mol) of N-ethyl-N-(3,3,5-trimethylcyclohexyl)pyrrolidinium iodide and 183 mL of deionized water, add 18.8 g (0.08 mol, 99%, Aldrich) of AgO. Stir the reaction mixture in the dark for 12 hours. The mixture is then filtered. The resulting filtrate is an aqueous solution of N-ethyl-N-(3,3,5-trimethylcyclohexyl)pyrrolidinium hydroxide. Quantitation of this compound is performed by proton NMR.

[0070] Example 2: Preparation of FER framework IZM-8 zeolite 0.43 g of sodium hydroxide (99.5 wt %, Aldrich) was mixed with 5.26 g of deionized water. 2.36 g of FAU framework zeolite (CBV720, SiO2 / Al2O3 = 34.7, Zeolyst, LOI = 8.54%) was added to the mixture, and the resulting mixture was stirred for 15 minutes. 2.65 g of an aqueous solution of N-ethyl-N-(3,3,5-trimethylcyclohexyl)pyrrolidinium hydroxide (21.68 wt %) prepared according to Example 1 was added to the synthesis mixture and stirred for 10 minutes. The synthesis mixture was stirred for 24 hours. The molar composition of the mixture was as follows: 1 SiO2:0.03 Al2O3:0.074 R:0.165 Na2O:13.4 H2O, i.e., the SiO2 / Al2O3 ratio was 33. The precursor gel was homogenized and then transferred to an autoclave. The autoclave was sealed and heated to 150°C for 6 days while stirring at 35 rpm using a rotary spit system. The resulting crystalline product was filtered, washed with deionized water, and dried overnight at 100°C. The solid was then placed in a muffle furnace and subjected to a calcination process. The calcination cycle consisted of a 1.5°C / min ramp to 200°C, a 2-hour steady-state hold at 200°C, a 1°C / min ramp to 550°C, and a 8-hour steady-state hold at 550°C, followed by a return to ambient temperature.

[0071] The calcined solid product was analyzed by X-ray diffraction and found to consist of FER framework IZM-8 zeolite with a purity of 91 wt%. The SiO2 / Al2O3 molar ratio of the product was determined to be 19 by X-ray fluorescence analysis. The BET specific surface area was 345 m 2 / g, micropore volume is 0.122 cm 3 / g.

[0072] Example 3: Preparation of FER framework IZM-8 zeolite 0.33 g of sodium hydroxide (99.5 wt %, Aldrich) was mixed with 4.29 g of deionized water. 2.17 g of FAU framework zeolite (CBV780, SiO2 / Al2O3 = 96.2, Zeolyst, LOI = 14%) was added to this mixture, and the resulting mixture was stirred for 15 minutes. 3.23 g of an aqueous solution of N-ethyl-N-(3,3,5-trimethylcyclohexyl)pyrrolidinium hydroxide (26.2 wt %) prepared according to Example 1 was added to the synthesis mixture and stirred for 10 minutes. 0.11 g of sodium aluminate (NaAlO2, 53 wt % Al2O3, Carlo Erba) was then added to the synthesis mixture, and the mixture was stirred for 24 hours. The molar composition of this mixture is as follows: 1 SiO2:0.031 Al2O3:0.12 R:0.165 Na2O:13.6 H2O, i.e., the SiO2 / Al2O3 ratio is 33. The precursor gel is homogenized and then transferred to an autoclave. The autoclave is sealed and heated at 150 °C for 6 days while stirring at 35 rpm using a rotary spit system. The resulting crystalline product is filtered, washed with deionized water, and dried overnight at 100 °C. The solid is then placed in a muffle furnace for the calcination step. The calcination cycle involves ramping the temperature to 200 °C at 1.5 °C / min, maintaining a steady state at 200 °C for 2 hours, ramping the temperature to 550 °C at 1 °C / min, maintaining a steady state at 550 °C for 8 hours, and then returning to ambient temperature.

[0073] The calcined solid product was analyzed by X-ray diffraction and was found to consist of FER framework IZM-8 zeolite with a purity of 91 wt%. The diffraction pattern obtained for this solid is shown in Figure 2. The SiO2 / Al2O3 molar ratio of this product was determined to be 19.5 by X-ray fluorescence analysis. The BET specific surface area was 350 m 2 / g, micropore volume is 0.120 cm 3 / g.

[0074] Example 4 Preparation of Seeded FER Framework IZM-8 Zeolite 0.33 g of sodium hydroxide (99.5 wt %, Aldrich) was mixed with 4.26 g of deionized water. 2.14 g of FAU framework zeolite (CBV780, SiO2 / Al2O3 = 96.2, Zeolyst, LOI = 14%) was added to this mixture, and the resulting mixture was stirred for 15 minutes. 3.18 g of an aqueous solution of N-ethyl-N-(3,3,5-trimethylcyclohexyl)pyrrolidinium hydroxide (26.2 wt %) prepared according to Example 1 was added to the synthesis mixture and stirred for 10 minutes. 0.10 g of sodium aluminate (NaAlO2, 53 wt % Al2O3, Carlo Erba) was then added to the synthesis mixture, and the mixture was stirred for 24 hours. The molar composition of this mixture is as follows: 1 SiO2:0.03 Al2O3:0.12 R:0.168 Na2O:13.6 H2O, i.e., an SiO2 / Al2O3 ratio of 33. To this mixture, seed crystals of FER framework zeolite (0.17 g of FER zeolite with an SiO2 / Al2O3 molar ratio of 9.9) are added. The precursor gel is homogenized and then transferred to an autoclave. The autoclave is sealed and heated at 150 °C for 3 days while stirring at 35 rpm using a rotary spit system. The resulting crystalline product is filtered, washed with deionized water, and dried overnight at 100 °C. The solid is then placed in a muffle furnace for the calcination step. The firing cycle was performed by ramping the temperature to 200°C at 1.5°C / min, holding steady at 200°C for 2 hours, ramping the temperature to 550°C at 1°C / min, holding steady at 550°C for 8 hours, and then returning to ambient temperature.

[0075] The calcined solid product was analyzed by X-ray diffraction and determined to consist of FER framework IZM-8 zeolite (ICDD file, PDF 01-073-9977) with a purity of over 99 wt%. The diffraction pattern obtained for this solid is shown in Figure 3. The SiO2 / Al2O3 molar ratio of this product was determined to be 15.8 by X-ray fluorescence analysis. The BET specific surface area was 364 m 2 / g, micropore volume is 0.128 cm 3 / g.

[0076] Example 5 Preparation of Seeded FER Framework IZM-8 Zeolite 0.33 g of sodium hydroxide (99.5 wt %, Aldrich) was mixed with 4.26 g of deionized water. 2.14 g of FAU framework zeolite (CBV780, SiO2 / Al2O3 = 96.2, Zeolyst, LOI = 14%) was added to this mixture, and the resulting mixture was stirred for 15 minutes. 3.18 g of an aqueous solution of N-ethyl-N-(3,3,5-trimethylcyclohexyl)pyrrolidinium hydroxide (26.2 wt %) prepared according to Example 1 was added to the synthesis mixture and stirred for 10 minutes. 0.10 g of sodium aluminate (NaAlO2, 53 wt % Al2O3, Carlo Erba) was then added to the synthesis mixture, and the mixture was stirred for 24 hours. The molar composition of this mixture is as follows: 1 SiO2:0.03 Al2O3:0.12 R:0.168 Na2O:13.6 H2O, i.e., an SiO2 / Al2O3 ratio of 33. To this mixture, seed crystals of FER framework zeolite (0.087 g of FER zeolite with an SiO2 / Al2O3 molar ratio of 9.9) are added. The precursor gel is homogenized and then transferred to an autoclave. The autoclave is sealed and heated at 150 °C for 3 days while stirring at 35 rpm using a rotary spit system. The resulting crystalline product is filtered, washed with deionized water, and dried overnight at 100 °C. The solid is then placed in a muffle furnace for the calcination step. The firing cycle was performed by ramping the temperature to 200°C at 1.5°C / min, holding steady at 200°C for 2 hours, ramping the temperature to 550°C at 1°C / min, holding steady at 550°C for 8 hours, and then returning to ambient temperature.

[0077] The calcined solid product was analyzed by X-ray diffraction and confirmed to consist of FER framework IZM-8 zeolite (ICDD file, PDF 01-073-9977) with a purity of over 99 wt%. The BET specific surface area was 360 m 2 / g, micropore volume is 0.125 cm 3 / g.

[0078] Example 6: Synthesis not according to the invention 0.297 g of sodium hydroxide (99.5 wt %, Aldrich) was mixed with 6.6 g of deionized water. 2.36 g of FAU framework zeolite (CBV720, SiO2 / Al2O3 = 34.7, Zeolyst, LOI = 8.54%) was added to the mixture, and the resulting mixture was stirred for 15 minutes. 1.52 g of an aqueous solution of N-ethyl-N-(3,3,5-trimethylcyclohexyl)pyrrolidinium hydroxide (26.20 wt %) prepared according to Example 1 was added to the synthesis mixture and stirred for 10 minutes. The mixture was stirred for 24 hours. The molar composition of the mixture was as follows: 1 SiO2:0.03 Al2O3:0.074 R:0.165 Na2O:20 H2O, i.e., a SiO2 / Al2O3 ratio of 33. The precursor gel was homogenized and then transferred to an autoclave. The autoclave was sealed and heated to 150°C for 6 days while stirring at 35 rpm using a rotary spit system. The resulting crystalline product was filtered, washed with deionized water, and dried overnight at 100°C. The solid was then placed in a muffle furnace and subjected to a calcination process. The calcination cycle consisted of a 1.5°C / min ramp to 200°C, a 2-hour steady-state hold at 200°C, a 1°C / min ramp to 550°C, and a 8-hour steady-state hold at 550°C, followed by a return to ambient temperature.

[0079] The calcined solid product was analyzed by X-ray diffraction and determined to consist of MOR framework zeolite (ICDD file, PDF 04-023-4678) with a purity of greater than 99 wt%.

Claims

1. A method for producing high purity FER framework IZM-8 zeolite, comprising at least the following steps: i) in an aqueous medium, Oxide form SiO ２ Silicon and oxide forms of Al ２ O ３ FAU framework zeolite as a source of aluminum, a nitrogen-containing organic compound R, where R is N-ethyl-N-(3,3,5-trimethylcyclohexyl)pyrrolidinium hydroxide; at least one alkali metal and / or alkaline earth metal M of valence n, where n is an integer greater than or equal to 1; and Optionally, oxide form Y ２ O ３ at least one trivalent element source wherein the mixture has the following molar composition: (SiO ２（ＦＡＵ） ) / (Al ２ O ３（ＦＡＵ） +Y ２ O ３ ) is in the range of 6 to 200, preferably in the range of 6 to 100, H ２ O / (SiO ２（ＦＡＵ） ) is in the range of 1 to 16, preferably in the range of 5 to 14, R / (SiO ２（ＦＡＵ） ) is in the range of 0.01 to 0.5, preferably in the range of 0.04 to 0.3, M ２／ｎ O / (SiO ２（ＦＡＵ） ) is in the range of 0.005 to 0.45, preferably in the range of 0.05 to 0.2, Here, Y is one or more trivalent elements selected from the group consisting of aluminum, boron, and gallium, and SiO ２（ＦＡＵ） is SiO supplied by FAU Zeolite ２ is the amount of Al ２ O ３（ＦＡＵ） is Al supplied by FAU Zeolite ２ O ３ and M is one or more alkali metals and / or alkaline earth metals selected from lithium, sodium, potassium, calcium, magnesium, and mixtures of at least two of these metals; mixing the mixture until a homogeneous precursor gel is obtained; ii) aging the homogeneous precursor gel obtained at the end of step i), with or without stirring, at a temperature ranging from 15°C to 100°C for a period ranging from 10 minutes to 48 hours; iii) hydrothermally treating the precursor gel obtained at the end of step ii) at a temperature ranging from 120°C to 220°C for a period ranging from 12 hours to 7 days, both ends included, until the FER framework-type IZM-8 zeolite is formed.

2. 2. The method of claim 1, wherein M is sodium, and preferably the source of at least one alkali metal M is sodium hydroxide.

3. 10. The method of any preceding claim, wherein Y is aluminum.

4. 10. The method according to any one of the preceding claims, wherein seed crystals of FER framework-type zeolite are added to the reaction mixture of step i) or to the homogeneous precursor gel of step ii) in an amount ranging from 0.01% to 10% of the total mass of the sources of Si and Al elements in anhydrous form used in the reaction mixture, and wherein the seed crystals are not included in the total mass of the sources of Si and Al elements.

5. 10. The method according to any one of the preceding claims, wherein the aging in step ii) is carried out at ambient temperature with stirring for a period ranging from 6 to 24 hours, both ends included.

6. 10. The method according to any one of the preceding claims, wherein the hydrothermal treatment of step iii) is carried out under autogenous reaction pressure.

7. 10. The method according to any one of the preceding claims, wherein the hydrothermal treatment of step iii) is carried out at a temperature in the range of 140 to 195°C.

8. 10. A process according to any one of the preceding claims, wherein after carrying out step iii), the solid phase formed from the FER framework-type IZM-8 zeolite obtained at the end of step iii) is filtered, washed and dried at a temperature ranging from 20 to 150°C, preferably at a temperature ranging from 60 to 100°C, for a period ranging from 5 to 24 hours to obtain a dried zeolite.

9. 9. The method of claim 8, wherein the dried zeolite is then calcined at a temperature in the range of 450 to 700°C for a period in the range of 2 to 20 hours, optionally with a gradual increase in temperature prior to the calcination.

10. SiO having a purity of 90% by weight or more, preferably a purity of more than 95% by weight ２ / Al ２ O ３ IZM-8 zeolite with a FER framework type, having a ratio in the range of 15 to 30, inclusive, preferably in the range of 10 to 25, inclusive, and obtainable by the process according to any one of claims 1 to 9.

11. SiO having a purity of 90% by weight or more, preferably a purity of more than 95% by weight ２ / Al ２ O ３ IZM-8 zeolite with a FER framework type, obtained by the process according to claim 9, wherein the ratio is in the range of 15 to 30, inclusive, preferably in the range of 10 to 25, inclusive, d measured by X-ray diffraction pattern ｈｋｌ The mean values ​​and relative intensities of the following are as follows, where VS = very strong; S = strong; m = moderate; mw = slightly weak; w = weak; vw = very weak, and the relative intensity I ｒｅｌ is given in relation to a relative intensity scale in which the most intense line of the X-ray diffraction pattern is assigned a value of 100: vw<15; 15≦w≦30; 30≦mw<50; 50≦m<65; 65≦S<85; VS≧85. Table 1

12. Micropore volume of 0.122 to 0.136 cm ３ / g, and the BET specific surface area is in the range of 325 to 400 m ２ 12. The FER framework-type IZM-8 zeolite of claim 11, wherein the ZnO content is in the range of 0.15 wt. / g.

Images