Ferrosilicate SSZ-70 molecular sieve, its synthesis and use

Abstract

A ferrosilicate molecular sieve having a SSZ-70 framework structure and a method for its manufacture are disclosed, which can be used in the dewaxing process of paraffinic hydrocarbon feedstocks.

Description

[Technical Field]

[0001] This disclosure * The present disclosure also relates to a process for dewaxing paraffinic hydrocarbon oils using a catalyst comprising the above molecular sieve. [Background technology]

[0002] Molecular sieves are classified by the Structure Commission of the International Zeolite Society according to the rules of the IUPAC Commission on Zeolite Nomenclature, which assigns three-letter codes to framework zeolites and other crystalline microporous molecular sieves whose structures are defined, as described, for example, in the "Atlas of Zeolite Framework Types" (Sixth Revised Edition, Elsevier, 2007).

[0003] SSZ-70 is one of the molecular sieves with a defined structure, and this framework material * SSZ-70 is a polymorph of MWW and can be considered as a disordered ABC-type stack of MWW layers. The MWW framework structure is characterized by two independent multidimensional channel systems. One pore system is defined by two-dimensional 10-membered ring (10-MR) sinusoidal channels. The other is composed of 12-MR supercages connected by 10-MR windows.

[0004] Currently, hydroisomerization catalysts generally comprise dual-function catalysts having an acid function and a precious metal (PM) function. The acidity is typically provided by a molecular sieve component, and the PM function is most often provided by platinum or palladium supported on and / or in the catalyst. The molecular sieves used in currently available catalysts have a specific content of aluminum and / or silica to control acidity. These catalysts exhibit very good activity but also suffer from relatively high cracking.

[0005] The present disclosure provides isomorphously substituted (Al for Fe), i.e., having iron (Fe) in place of the more common aluminum (Al) in tetrahedrally coordinated framework positions. * The present invention is directed to SVY molecular sieves and their use as hydroisomerization catalysts. The substitution of iron into the framework allows for modification of the acidic properties of the molecular sieve, resulting in a catalyst with superior properties compared to currently available catalysts. The performance advantages of the catalyst include improved yields (less cracking) and a more favorable product distribution. Summary of the Invention

[0006] In a first embodiment, in its as-synthesized form, it contains an organic structure directing agent in its pores. * - SVY framework type ferrosilicate molecular sieve, wherein the organic structure directing agent is represented by the formula (1): [ka] wherein R and R' are each independently selected from isopropyl, isobutyl, and cyclohexyl. The ferrosilicate molecular sieve is provided as follows:

[0007] In a second aspect, * 1. A method for synthesizing a ferrosilicate molecular sieve of the -SVY framework type, comprising: (1) a process for synthesizing a ferrosilicate molecular sieve comprising: (a) a source of iron oxide; (b) a source of silicon oxide; (c) a source of alkali or alkaline earth metal (M); (d) an organic structure directing agent (Q); (e) a source of hydroxide ions; and (f) water, the process comprising: [Table 1A] and (2) subjecting the reaction mixture to crystallization conditions sufficient to form crystals of the ferrosilicate molecular sieve, wherein the organic structure directing agent has the formula (1): [ka] wherein R and R' are each independently selected from isopropyl, isobutyl, and cyclohexyl. The method is represented by the following formula:

[0008] In a third aspect, there is provided a process for hydroisomerization of a paraffinic hydrocarbon feedstock, comprising: subjecting said paraffinic hydrocarbon feedstock to hydroisomerization conditions with hydrogen and * and obtaining a product having increased branched hydrocarbons relative to the hydrocarbon feedstock, wherein the catalyst further comprises 0.01 to 10 wt. % of a noble metal. The following is further disclosed regarding the present invention. [1] * -SVY framework type ferrosilicate molecular sieve, which in its as-synthesized form contains an organic structure directing agent in its pores, The organic structure directing agent has formula (1): [ka] wherein R and R' are each independently selected from isopropyl, isobutyl, and cyclohexyl. The ferrosilicate molecular sieve is represented by [2] SiO 2 / Fe 2 O 3 The ferrosilicate molecular sieve according to [1], wherein the molar ratio of [3] SiO 2 / Fe 2 O 3 The ferrosilicate molecular sieve according to [1], wherein the molar ratio of [4] * A method for synthesizing a ferrosilicate molecular sieve of -SVY framework type, comprising the steps of: (1)(a) a source of iron oxide; (b) a source of oxide of silicon; and (c) a source of alkali or alkaline earth metal (M); and (d) an organic structure directing agent (Q); (e) a source of hydroxide ions; and (f) Water and and having the following composition, expressed in molar ratios: Table 1A preparing a reaction mixture as follows: (2) subjecting said reaction mixture to crystallization conditions sufficient to form crystals of said ferrosilicate molecular sieve; Including, The organic structure directing agent has formula (1):

change

[10] [9] The process of [9], wherein the paraffinic hydrocarbon feedstock comprises n-C8+ hydrocarbons.

[11] SiO of the ferrosilicate molecular sieve 2 / Fe 2 O 3 The process according to [9], wherein the molar ratio of is in the range of 25 to 750.

[12] SiO of the ferrosilicate molecular sieve 2 / Fe 2 O 3 The process according to [9], wherein the molar ratio of is in the range of 50 to 500.

[13] [9] The process of [9], wherein the noble metal comprises platinum, palladium, or a mixture thereof.

[14] The hydroisomerization conditions are a temperature of 200°C to 450°C, a pressure of 0.5 to 20 MPa, and a reaction time of 0.1 to 10 hours. -1 and 35.6 to 3560 Nm 3 / m 3 [9], comprising a hydrogen circulation rate of [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 shows the powder X-ray diffraction (XRD) pattern of the as-synthesized ferrosilicate SSZ-70 prepared according to Example 1.

[0010] [Figure 2] FIG. 2 shows the powder XRD pattern of the calcined ferrosilicate SSZ-70 prepared according to Example 1.

[0011] [Figure 3] FIG. 3 shows the powder XRD pattern of the as-synthesized ferrosilicate SSZ-70 prepared according to Example 2.

[0012] [Figure 4] FIG. 4 shows the powder XRD pattern of the as-synthesized ferrosilicate SSZ-70 prepared according to Example 3.

[0013] [Figure 5(A)] FIG. 5(A) is a plot of conversion or yield versus temperature for n-decane hydroconversion over a Pd / Fe-SSZ-70 catalyst according to Example 21.

[0014] [Figure 5(B)] FIG. 5(B) is a plot of conversion or yield versus temperature for n-decane hydroconversion over a Pd / Al-SSZ-70 catalyst according to Example 21.

[0015] [Figure 6(A)] FIG. 6(A) is a plot of yield versus conversion for n-decane hydroconversion over a Pd / Fe-SSZ-70 catalyst according to Example 21.

[0016] [Figure 6(B)] FIG. 6(B) is a plot of yield versus conversion for n-decane hydroconversion over a Pd / Al-SSZ-70 catalyst according to Example 21.

[0017] [Figure 7(A)] FIG. 7(A) is a plot of C10 isomer distribution versus conversion for n-decane hydroconversion over a Pd / Fe-SSZ-70 catalyst according to Example 21.

[0018] [Figure 7(B)] FIG. 7(B) is a plot of C10 isomer distribution versus conversion for n-decane hydroconversion over a Pd / Al-SSZ-70 catalyst according to Example 21. DETAILED DESCRIPTION OF THE INVENTION

[0019] definition The term "ferrosilicate" refers to a molecular sieve having a framework built from FeO and SiO tetrahedral units. The ferrosilicate may contain only the specified oxides (in which case it may be referred to as a "pure ferrosilicate") or may further contain other oxides.

[0020] term" * -SVY" is approved by the Structure Committee of the International Zeolite Society * -Refers to the SVY topology type. * Examples of materials of the -SVY topology type include SSZ-70 and ECNU-5.

[0021] The term "as-synthesized" refers to the molecular sieve in its form after crystallization and before removal of the organic structure directing agent.

[0022] The term "Cn" hydrocarbon, where n is a positive integer (e.g., 1, 2, 3, 4, 5, etc.), means a hydrocarbon having n carbon atoms or atoms per molecule.

[0023] The term "Cn+" hydrocarbon, where n is a positive integer (e.g., 1, 2, 3, 4, 5, etc.), refers to a hydrocarbon having n or more carbon atoms per molecule.

[0024] The term "Cn-" hydrocarbon, where n is a positive integer (e.g., 1, 2, 3, 4, 5, etc.), refers to a hydrocarbon having n or fewer carbon atoms per molecule.

[0025] As used herein, the term "noble metal" generally refers to a metal selected from the group consisting of ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold.

[0026] The term "ferrosilicate SSZ-70" is sometimes abbreviated as "Fe-SSZ-70."

[0027] The term "aluminosilicate SSZ-70" is sometimes abbreviated as "Al-SSZ-70."

[0028] The term "M-SSZ-70" refers to the metallosilicate SSZ-70, which has a framework built from SiO4 and MO4 tetrahedral units, where M is Al or Fe.

[0029] The term "1,3-diisobutylimidazolium" is sometimes abbreviated as "DIBI."

[0030] The term "1,3-dicyclohexylimidazolium" is sometimes abbreviated as "DCHI."

[0031] Molecular sieve synthesis * The -SVY framework type ferrosilicate molecular sieve can be synthesized by (1) preparing a reaction mixture containing (a) a source of iron oxide, (b) a source of silicon oxide, (c) a source of alkali or alkaline earth metal (M), (d) an organic structure directing agent (Q), (e) a source of hydroxide ions, and (f) water; and (2) subjecting the reaction mixture to crystallization conditions sufficient to form crystals of the ferrosilicate molecular sieve.

[0032] The composition of the reaction mixture, expressed in molar ratios, is shown in Table 1: [Table 1] It may be within the range shown in FIG.

[0033] Suitable sources of iron include water-soluble iron salts (eg, ferric chloride, ferric nitrate, ferric sulfate).

[0034] Suitable silicon sources include colloidal suspensions of silica, precipitated silica, fumed silica, alkali metal silicates, and tetraalkyl orthosilicates (eg, tetraethyl orthosilicate).

[0035] The alkali or alkaline earth metal (M) is typically introduced into the reaction mixture along with a source of hydroxide ions. Examples of such metals include sodium and / or potassium, as well as lithium, rubidium, cesium, magnesium, and calcium. As used herein, the phrase "alkali or alkaline earth metal" does not mean that alkali metals and alkaline earth metals are used alternatively, but rather that one or more alkali metals may be used alone or in combination with one or more alkaline earth metals, and one or more alkaline earth metals may be used alone or in combination with one or more alkali metals.

[0036] The organic structure-directing agent (Q) is represented by the formula (1): [ka] wherein R and R' are each independently selected from isopropyl, isobutyl, and cyclohexyl. Specific examples of the organic structure directing agent include a 1,3-dialkylimidazolium cation, a 1,3-diisopropylimidazolium cation, a 1,3-diisobutylimidazolium cation, and a 1,3-dicyclohexylimidazolium cation.

[0037] Suitable sources of Q include hydroxides, chlorides, bromides, and / or other salts of quaternary ammonium compounds.

[0038] The reaction mixture may optionally contain a source of fluoride ions. The fluoride ion source may be any compound capable of releasing fluoride ions in the reaction mixture. Examples of fluoride ion sources include hydrogen fluoride; metal fluorides, preferably metal fluorides where the metal is sodium, potassium, calcium, magnesium, strontium, or barium; ammonium fluoride; or tetraalkylammonium fluorides, such as tetramethylammonium fluoride or tetraethylammonium fluoride. The molar ratio of F / SiO2 in the reaction mixture may be in the range of 0 to 1.0 (e.g., 0.01 to 1.0, 0.05 to 1.0, 0 to 0.5, 0.01 to 0.5, or 0.05 to 0.5).

[0039] The synthesis mixture may also contain seed crystals (usually * The reaction mixture may contain seed crystals of a -SVY framework molecular sieve, preferably in an amount of 0.01 to 10,000 ppm by weight (e.g., 100 to 5000 ppm by weight) based on the reaction mixture. * - It may be advantageous to improve the selectivity of SVY and / or shorten the crystallization process.

[0040] Crystallization of the desired molecular sieve from the reaction mixture can be carried out in a suitable reaction vessel, such as a polypropylene bottle or a Teflon-lined or stainless steel autoclave, under static, end-over-end, or stirred conditions at a temperature of 120°C to 200°C (e.g., 140°C to 180°C) for a time sufficient for crystallization to occur at the temperature used, e.g., about 3 to 30 days (e.g., 5 to 25 days). Crystallization is typically carried out under pressure in an autoclave, such that the reaction mixture is subject to autogenous pressure.

[0041] Once the desired molecular sieve crystals have formed, the solid product may be separated from the reaction mixture by standard mechanical separation techniques such as centrifugation or filtration. The recovered crystals are washed with water and then dried for a few seconds to a few minutes (e.g., 5 seconds to 10 minutes for flash drying) or for several hours (e.g., 4 hours to 24 hours for oven drying at 75°C to 150°C) to yield the as-synthesized molecular sieve crystals. The drying step can be carried out under vacuum or at atmospheric pressure.

[0042] As a result of the crystallization process, the recovered crystalline molecular sieve product contains within its pores at least a portion of the structure directing agent used in its synthesis.

[0043] The as-synthesized ferrosilicate molecular sieve may be subjected to heat treatment, ozone treatment, or other treatment to remove some or all of the organic structure-directing agent used in its synthesis. Removal of the organic structure-directing agent can be accomplished using a heat treatment (e.g., calcination) in which the as-synthesized material is heated in air or an inert gas at a temperature sufficient to remove some or all of the organic structure-directing agent. Pressures below atmospheric pressure may be used for the heat treatment, but atmospheric pressure is preferred for convenience. The heat treatment may be carried out at a temperature of at least 370°C for at least 1 minute, typically for up to 20 hours (e.g., 1 to 12 hours). The heat treatment may be carried out at temperatures up to 925°C. For example, the heat treatment may be carried out in air at a temperature of 400°C to 600°C for 1 to 8 hours.

[0044] The ferrosilicate molecular sieve (from which some or all of the organic structure directing agent has been removed) may be combined with a hydrogenation metal component. The hydrogenation metal component may be selected from molybdenum, tungsten, rhenium, nickel, cobalt, chromium, manganese, or a noble metal such as platinum or palladium, which performs a hydrogenation-dehydrogenation function. Such a hydrogenation metal component may be incorporated into the composition by one or more of the following processes: cocrystallization, ion exchange into the composition, impregnation into the composition, or physical mixing with the composition. The amount of metal may range from 0.001 to 20 wt. % (0.01 to 10 wt. %, or 0.5 to 2.0 wt. %) based on the catalyst.

[0045] Once synthesized, the ferrosilicate molecular sieve may be incorporated into a catalyst composition by combining it with another material that is resistant to the temperatures and other conditions used in organic conversion processes. Such resistant materials can be selected from active materials, inactive materials, synthetic zeolites, natural zeolites, inorganic materials, or mixtures thereof. Examples of such resistant materials can be selected from clays, silica, metal oxides such as alumina, or mixtures thereof. The inorganic materials may be naturally occurring or may be in the form of gelatinous precipitates or gels including mixtures of silica and metal oxides. The use of resistant materials in conjunction with the ferrosilicate molecular sieve, i.e., mixed with the ferrosilicate molecular sieve or present during the synthesis of the as-synthesized material whose crystals are active, tends to alter the conversion and / or selectivity of the catalyst in a particular organic conversion process. The inert resistant material serves as a suitable diluent to control the amount of conversion in a given process, thereby enabling economical and uncomplicated production of the product without the use of other means to control the reaction rate. These materials can be incorporated into natural clays (e.g., bentonite and kaolin) to improve the crush strength of the catalyst under commercial operating conditions. The inert resistant material (i.e., clay, oxide, etc.) acts as a binder for the catalyst. In commercial applications, it is desirable to prevent the catalyst from disintegrating into a powder-like material, so a catalyst with good crush strength can be beneficial.

[0046] Naturally occurring clays that may be composited with the ferrosilicate molecular sieves include the montmorillonite and kaolin families, which include sub-bentonites and kaolins commonly known as Dixie clays, McNamee clays, Georgia clays, and Florida clays, or other clays whose primary mineral component is halloysite, kaolinite, dickite, nacrite, or anoxite. Such clays may be used in the raw state as originally mined, or may first be subjected to calcination, acid treatment, or chemical modification.

[0047] Binders useful for compositing with the ferrosilicate molecular sieves also include inorganic oxides selected from silica, zirconia, titania, magnesia, beryllia, alumina, or mixtures thereof.

[0048] In addition to the materials mentioned above, the ferrosilicate molecular sieves may be composited with porous matrix materials such as silica-alumina, silica-magnesia, silica-zirconia, silica-thoria, silica-beryllia, silica-titania, and ternary compositions such as silica-alumina-thoria, silica-alumina-zirconia, silica-alumina-magnesia, and silica-magnesia-zirconia.

[0049] The relative proportions of ferrosilicate molecular sieve and inorganic oxide matrix may vary widely, with the molecular sieve content ranging from 1 to 95 weight percent (eg, 20 to 90 weight percent) of the composite material.

[0050] The catalyst is used in a conventional manner, for example in the form of spheres or extrudates.

[0051] Molecular sieve characterization The chemical composition, in terms of molar ratios, of the ferrosilicate molecular sieve in its as-synthesized and anhydrous form may be within the ranges shown in Table 2. [Table 2] wherein Q comprises an organic structure directing agent as described hereinabove, and M is an alkali or alkaline earth metal.

[0052] As taught by U.S. Pat. No. 7,108,843, the molecular sieve SSZ-70 has a powder X-ray diffraction pattern in its as-synthesized form that includes at least the peaks shown in Table 3 below, and in its calcined form that includes at least the peaks shown in Table 4. [Table 3] [Table 4]

[0053] As one skilled in the art will appreciate, measurements of the parameter 2-theta are subject to both human and mechanical error, which may combine to introduce an uncertainty of approximately ±0.15° into each reported value of 2-theta. The d-spacing values ​​have a deviation determined based on a corresponding deviation of ±0.15° of 2-theta when converted to the corresponding d-spacing value using Bragg's law. The relative intensity of a line, I / Io, represents the ratio of the peak intensity above background to the intensity of the most intense line. The relative intensities are represented by the symbols VS = very strong (>60), S = strong (≧40 and ≦60), M = moderate (≧20 and <40), and W = weak (<20).

[0054] Minor variations in the diffraction pattern can result from variations in the molar ratio of framework species in a particular sample, resulting in changes in lattice constants. Furthermore, sufficiently small crystals can affect peak shape and intensity, leading to significant peak broadening. Minor variations in the diffraction pattern can also result from changes in the organic compounds used in the preparation. Calcination can also slightly shift the XRD pattern. Despite these small perturbations, the basic crystal lattice structure remains unchanged.

[0055] Hydroisomerization of paraffinic hydrocarbon feedstocks The ferrosilicate molecular sieve is suitable for use as a catalyst in the hydroisomerization of a paraffinic hydrocarbon feedstock by contacting the catalyst with hydrogen under hydroisomerization conditions to yield a product enriched in branched hydrocarbons relative to the hydrocarbon feedstock.

[0056] The hydroisomerization conditions include a temperature of 200°C to 450°C (for example, 250°C to 400°C), a pressure of 0.5 to 20 MPa (for example, 1 to 15 MPa), and a time of 0.1 to 10 hours. -1 (e.g., 0.5 to 5 hours) -1 ) liquid hourly space velocity, and 35.6 to 3560 Nm 3 / m 3 (e.g., 356 to 1781 Nm 3 / m 3 ) hydrogen circulation rate.

[0057] When the hydrocarbon feedstock contains n-C hydrocarbons (e.g., n-C hydrocarbons or n-C hydrocarbons), the hydrocarbon feedstock is not limited to a specific type. More specifically, examples of such hydrocarbon feedstocks include relatively light fractions such as kerosene and jet fuel; high-boiling feedstocks such as any kind of crude oil, atmospheric residue (atmospheric residue), vacuum tower residue, vacuum residue (vacuum residue), cycle oil, synthetic crude oil (e.g., shale oil, tar oil, etc.), gas oil, vacuum gas oil, waxy bottoms, and fuel or wax fractions derived from FT synthetic oil; and other heavy oils.

[0058] In some embodiments, at least a portion of the feedstock may represent a feedstock derived from a biosource. In this discussion, biofeed or feedstock refers to a hydrocarbon feedstock derived from biological feedstock components such as vegetable oils, animal fats, fish oils, pyrolysis oils, and microalgae lipids / oils. [Example]

[0059] The following examples, by way of illustration, are intended to be non-limiting.

[0060] Example 1: Synthesis of ferrosilicate SSZ-70 A 23 mL Teflon liner was charged with 1.5628 g of deionized water, 0.1550 g of 50% aqueous NaOH, and 9.7013 g of 1,3-dicyclohexylimidazolium hydroxide (10%). This mixture was stirred until a homogeneous solution was obtained. 1.2 g of fumed silica was then slowly added and stirred until a homogeneous solution was obtained. Finally, 0.1597 g of Fe(NO3)3·9H2O was added. The resulting gel had the following molar composition: 1 SiO2: 0.01 Fe2O3: 0.1 NaOH: 0.2 Q-OH: 30 H2O The liner was capped and sealed in a 23 mL Parr autoclave vessel. The autoclave vessel was then heated in a convection oven under end-over-end conditions at 150°C for 7 days. The product was isolated by filtration, washed with deionized water, and then dried in an oven at 95°C.

[0061] The product was pure SSZ-70 by powder XRD. Figure 1 shows the powder XRD pattern of the as-synthesized product.

[0062] The SiO2 / Fe2O3 molar ratio of the as-synthesized product was 89 as determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES).

[0063] Thermogravimetric analysis (TGA) was performed by heating the sample under air flow from 20° C. to 900° C. at a heating rate of 1° C. / min. TGA showed a mass loss of approximately 25%.

[0064] The as-synthesized Fe-SSZ-70 samples were calcined in a muffle furnace by increasing the temperature in flowing air at 1°C / min to 120°C, holding the temperature at 120°C for 2 hours, and then increasing the temperature in air at 1°C / min to 550°C. After holding the temperature at 550°C for 5 hours, each sample was allowed to cool to ambient temperature. Figure 2 shows the powder XRD pattern of the calcined form of Fe-SSZ-70.

[0065] The calcined sample (H-form) was measured by nitrogen physisorption and the data were analyzed using the t-plot method. The micropore volume of this material was 0.17 cm 3 / g.

[0066] Isopropylamine temperature-programmed desorption (IPAM-TPD) was performed on the calcined material (H-form). Analysis of the data revealed that the acid site density was 180 μmol H + / g.

[0067] The physicochemical properties of the as-synthesized and calcined Fe-SSZ-70 materials are summarized in Table 6 below.

[0068] Example 2: Synthesis of ferrosilicate SSZ-70 A 23 mL Teflon liner was charged with 0.1808 g of 50% aqueous NaOH and 9.9602 g of 1,3-diisobutylimidazolium hydroxide (9%). The mixture was stirred until a homogeneous solution was obtained. 1.4 g of fumed silica was then slowly added and stirred until a homogeneous solution was obtained. Finally, 0.1854 g of Fe(NO3)3·9H2O was added. A stream of nitrogen gas was blown over the mixture until excess water had evaporated adequately. The resulting gel had the following molar composition: 1 SiO2: 0.01 Fe2O3: 0.1 NaOH: 0.2 Q-OH: 20 H2O The liner was capped and sealed in a 23 mL Parr autoclave vessel. The autoclave vessel was then heated in a convection oven under end-over-end conditions at 150°C for 7 days. The product was isolated by filtration, washed with deionized water, and then dried in an oven at 95°C.

[0069] The above product was pure SSZ-70 by powder XRD. Figure 3 shows the powder XRD pattern of the as-synthesized product.

[0070] Example 3: Synthesis of ferrosilicate SSZ-70 A polyethylene bottle was charged with 5.0 g of tetraethyl orthosilicate (TEOS) followed by 26.41 g of 1,3-diisobutylimidazolium hydroxide (9%). The mixture was stirred overnight to hydrolyze the TEOS. A stream of nitrogen gas was blown over the mixture until the ethanol produced by hydrolysis evaporated. Next, 0.4997 g of hydrofluoric acid (48%) was added and the mixture was homogenized with a spatula. Finally, 0.1977 g of Fe(NO3)3·9H2O was added and the mixture was homogenized with a spatula. The resulting gel had the following molar composition: 1 SiO2: 0.01 Fe2O3: 0.5 HF: 0.5 Q-OH: 5 H2O The contents of the polyethylene bottle were transferred to a Teflon liner. The liner was capped and sealed in a 23 mL Parr autoclave vessel. The autoclave vessel was then heated in a convection oven under static conditions at 150°C for 19 days. The product was isolated by filtration, washed with deionized water, and then dried in an oven at 95°C.

[0071] The above product was pure SSZ-70 by powder XRD. Figure 4 shows the powder XRD pattern of the as-synthesized product.

[0072] Examples 4-16 Synthesis of ferrosilicate SSZ-70 To prepare the Fe-SSZ-70 materials of Examples 4-16, the process conditions and molar ratios outlined in Table 5 below were applied.

[0073] Each of the resulting materials was determined by powder XRD to be a zeolite material with the framework structure of SSZ-70. [Table 5]

[0074] Example 17 Synthesis of aluminosilicate SSZ-70 Aluminosilicate SSZ-70 (Al-SSZ-70) was prepared according to the procedure reported by R.H. Archer et al. (Chem. Mater. 2010, 22, 2563-2572). A 23 mL Teflon liner was charged with 1.6071 g of water, 0.1550 g of NaOH (50%), and 9.7011 g of 1,3-dicyclohexylimidazolium hydroxide (10%). The mixture was stirred until homogeneous. 38.4 mg of Reheis F-2000 aluminum hydroxide was then added to the mixture and stirred until homogeneous. 1.2 g of fumed silica was added to the mixture and stirred until homogeneous. The resulting gel had the following molar composition: 1 SiO2: 0.01 Al2O3: 0.1 NaOH: 0.2 Q-OH: 30 H2O The liner was capped and sealed in a 23 mL Parr autoclave vessel. The autoclave vessel was then heated in a convection oven under end-over-end conditions at 160°C for 120 hours. The product was isolated by filtration, washed with deionized water, and then dried in an oven at 95°C.

[0075] A sample of as-synthesized Al-SSZ-70 was calcined as described in Example 1.

[0076] The physicochemical properties of the as-synthesized and calcined Al-SSZ-70 materials are summarized in Table 6 below. [Table 6]

[0077] Example 18 Ammonium exchange Calcined metallosilicate zeolite (M-SSZ-70) prepared according to Examples 1 and 17 was converted to the ammonium form (NH4NO3) by adding the zeolite to a 10% NH4NO3 solution in a mass ratio of 10:1 10% NH4NO3 solution:M-SSZ-70 zeolite. + The solution was heated at 95°C for at least 2 hours. The solution was decanted and the process was repeated two more times. After the final exchange, the zeolite was washed with deionized water until the conductivity was less than 50 μS / cm and dried. The resulting NH4 + / M-SSZ-70 is a hydrogen type (H + / M-SSZ-70).

[0078] Example 19 Catalyst Preparation Ammonium-exchanged metallosilicate SSZ-70 zeolite (NH4 + The zeolite (M-SSZ-70) was ion-exchanged in an aqueous palladium nitrate solution at a pH of approximately 10 and a Pd loading of 0.5 wt %. The exchanged zeolite was washed with deionized water until the conductivity was less than 50 μS / cm and dried. The zeolite was then calcined in air at 482°C for 3 hours.

[0079] Example 20 Constraint index Hydrogen-type metallosilicate SSZ-70 zeolite (H +The catalyst (M-SSZ-70) was pelletized at 4-5 kpsi, crushed, and sized to 20-40 mesh. 0.47 g of this catalyst (dry weight determined by TGA at 600 °C) was then loaded into a 3 / 8-inch stainless steel tube, and catalytically inactive alundum was packed on both sides of the zeolite bed. The reactor tube was heated using an Applied Test Systems (ATS) furnace. Helium was introduced into the reactor at 23 mL / min and atmospheric pressure. The catalyst was dehydrated at 482 °C for 2 hours. If necessary, the reactor temperature was then reduced to a preselected reaction temperature (e.g., 454 °C). The helium flow rate was then adjusted to 9.4 mL / min, and an equimolar mixture of n-hexane (n-C6) and 3-methylpentane (3-MP) was introduced into the reactor at a rate of 0.48 mL / h. The feedstock was delivered via an ISCO pump. Fifteen minutes after the introduction of the raw materials, online sampling of the products into a gas chromatograph (GC) was started. Representative results are shown in Table 7. [Table 7]

[0080] The results in Table 7 reveal that Al-SSZ-70 exhibits significantly higher conversion at lower temperatures than Fe-SSZ-70, suggesting that the acid sites associated with the framework iron are weaker than those associated with the framework aluminum. The constraint index values ​​are essentially identical for both Al-SSZ-70 and Fe-SSZ-70, indicating that the difference in catalytic activity is not due to any difference in the framework.

[0081] Example 21 Hydroconversion of n-decane 0.5 g of the Pd-loaded sample from Example 19 was pelletized at 5000 psi, trimmed to a 20-40 mesh size, and packed into the center of a 23-inch long, 1 / 4-inch outer diameter stainless steel reactor tube. Alundum was packed upstream of the catalyst to preheat the feed. The operating conditions were as follows: 1200 psig total pressure, 8.3 mL / min downflow hydrogen flow rate (measured at 1 atmosphere and 25°C), and 0.66 mL / h downflow n-decane feed rate. All materials were first reduced in flowing hydrogen at approximately 315°C for 1 hour. The products were analyzed every 30 minutes by online capillary gas chromatography (GC). The raw GC data were collected by an automated data acquisition / processing system, and the hydrocarbon conversion was calculated from the raw data. Conversion is defined as the amount of n-decane that reacted to form other products (including iso-C10). Yields are expressed as mole percent of products other than n-decane and include the iso-C10 isomer as the output product. The results of n-decane hydroconversion for Fe-SSZ-70 are compared with those for Al-SSZ-70 in Figures 5(A)-(B), 6(A)-(B), and 7(A)-(B).

Claims

1. ＊ - a ferrosilicate molecular sieve of the SVY framework type, which in its as-synthesized form contains an organic structure directing agent in its pores, The organic structure directing agent has the formula (1): 【Chemistry 1】 wherein R and R' are each independently selected from isopropyl and isobutyl. The ferrosilicate molecular sieve is an imidazolium cation represented by

2. SiO ２ / Fe ２ O ３ 2. The ferrosilicate molecular sieve of claim 1, wherein the molar ratio of

3. SiO ２ / Fe ２ O ３ 2. The ferrosilicate molecular sieve of claim 1, wherein the molar ratio of

4. ＊ - A method for synthesizing a ferrosilicate molecular sieve of SVY framework type, comprising the steps of: (1) (a) a source of iron oxides; (b) a source of oxide of silicon; and (c) a source of an alkali or alkaline earth metal (M); and (d) an organic structure directing agent (Q); and (e) a source of hydroxide ions; and (f) water; and having the following composition, expressed in molar ratios: Table 1A preparing a reaction mixture as follows: (2) subjecting the reaction mixture to crystallization conditions sufficient to form crystals of the ferrosilicate molecular sieve; Including, The organic structure directing agent has the formula (1): 【Chemistry 1】 wherein R and R' are each independently selected from isopropyl and isobutyl. The imidazolium cation is represented by

5. The reaction mixture has the following composition, expressed in molar ratios: Table 1B The method of claim 4, wherein:

6. 5. The method of claim 4, wherein the crystallization conditions comprise heating the reaction mixture under autogenous pressure at a temperature of from 120° C. to 200° C. for a period of from 3 days to 30 days.

7. The method of claim 4 , wherein the reaction mixture further comprises a source of fluoride ions.

8. The F / SiO ２ The method of claim 7, wherein the molar ratio of is in the range of 0.01 to 1.0.

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