Title of Invention

"A CRYSTALLINE METERIAL COMPRISING A CHA FRAMEWORK TYPE MOLECULAR SIEVE AN AEI FRAMEWORK-TYPE MOLECULAR SIEVE"

Abstract The present invention relates to a crystalline material which, in its as-synthesized form, comprises at least a CHA framework type molecular sieve and an AEI framework-type molecular sieve, which, in its as-synthesized form, also contains in its intra-molecular structure a first directing agent for directing the synthesis of a CHA framework-type molecular sieve and a second directing agent for directing the synthesis of a AEI framework-type molecular sieve, said first and second directing agents being different.
Full Text The present invention relates to a crystalline material comprising a CHA framework type molecular sieve and an AEI framework-type molecular sieve.
FIELD OF INVENTION
[0001] This invention relates to a novel chabazite-containing molecular
sieve, its synthesis and its use in the conversion of oxygenates, particularly methanol, to olefins, particularly ethylene and propylene.
BACKGROUND OF INVENTION
[0002] The conversion of oxygenates to olefins (OTO) is currently the
subject of intense research because it has the potential for replacing the long¬
standing steam cracking technology that is today the industry-standard for
producing world scale quantities of ethylene and propylene. The very large
volumes involved suggest that substantial economic incentives exist for alternate
technologies that can deliver high throughputs of light olefins in a cost efficient
manner. Whereas steam cracking relies on non-selective thermal reactions of
naphtha range hydrocarbons at very high temperatures, OTO exploits catalytic and
microrarchitectural properties of acidic molecular sieves under milder temperature
conditions to produce high yields of ethylene and propylene from methanol.
[0003] Current understanding of the OTO reactions suggests a complex
sequence in which three major steps can be identified: (1) an induction period leading to the formation of an active carbon pool (alkyl-aromatics), (2) alkylation-dealkylation reactions of these active intermediates leading to products, and (3) a gradual build-up of condensed ring aromatics. OTO is therefore an inherently transient chemical transformation in which the catalyst is in a continuous state of change. The ability of the catalyst to maintain high olefin yields for prolonged periods of time relies on a delicate balance between the relative rates at which the above processes take place. The formation of coke-like molecules is of singular importance because their accumulation interferes with the desired reaction sequence in a number of ways. In particular, coke renders the carbon pool
inactive, lowers the rates of diffusion of reactants and products, increases the
potential for undesired secondary reactions and limits catalyst life.
[0004] Over the last two decades, many catalytic materials have been
identified as being useful for carrying out the OTO reactions. Crystalline microporous materials are the preferred catalysts today because they simultaneously address the acidity and morphological requirements for the reactions. Particularly preferred materials are eight-membered ring aluminosilicates, such as those having the chabazite and AEI framework types, and their silicoaluminophosphate counterparts, such as SAPO-34 and SAPO-18. These molecular sieves have cages that are sufficiently large to accommodate aromatic intermediates while still allowing the diffusional transport of reactants and products into and out of the crystals through regularly interconnected window apertures. By complementing such morphological characteristics with appropriate levels of acid strength and acid density, working catalysts are produced. Extensive research in this area indicates that silicoaluminophosphates are currently more effective OTO catalysts than aluminosilicates. In particular, the control of the silica to alumina molar ratio is a key requirement for the use of aluminosilicates in OTO reactions. Nevertheless, aluminosilicate zeolites continue to be explored for use in OTO and appear to have yet undiscovered potential.
[0005] Chabazite is a naturally occurring zeolite with the approximate
formula C^Al^Sia-^O?!. Three synthetic forms of chabazite are described in "Zeolite Molecular Sieves", by D. W. Breck, published in 1973 by John Wiley & Sons, the complete disclosure of which is incorporated herein by specific reference. The three synthetic forms reported by Breck are Zeolite "K-G", described in J. Chem. Soc., p. 2822 (1956), Barrer et al; Zeolite D, described in British Patent No. 868,846 (1961); and Zeolite R, described in U.S. Patent No. 3,030,181 (1962). Zeolite K-G zeolite has a silica:alumina mole ratio of 2.3:1 to 4.15:1, whereas zeolites D and R have silica:alumina mole ratios of 4.5:1 to 4.9:1 and 3.45:1 to 3.65:1, respectively.
|0006] U.S. Patent No. 4,544,538, incorporated herein by reference,
describes the synthesis of another synthetic form of chabazite, SSZ-13, using N-
alkyl-3-quinuclidinol, N,N,N-tri-alkyl-l-adamantylammonium cations and/or N,N,N-trialkyl-exoaminonorbornane as a directing agent in a conventional OH" medium. According to the '538 patent, SSZ-13 typically has a silica to alumina molar ratio of 8 to 50, but it is stated that higher molar ratios can be obtained by varying the relative ratios of the reactants in the synthesis mixture and/or by treating the zeolite with chelating agents or acids to remove aluminum from the zeolite lattice. However, attempts to synthesize SSZ-13 in OH' media at silica to alumina molar ratios in excess of 100 have been unsuccessful and have produced ITQ-1 or SSZ-23, depending on the alkali metal cation present. Moreover, increasing the silica to alumina molar ratio of SSZ-13 by dealumination has met little or no success.
[0007] Significant work has been conducted on the use of SSZ-13 as a
catalyst for MTO reactions. However, investigations to date have shown that the performance of SSZ-13 is always inferior to that of its silicoaluminophosphate analog, SAPO-34. See, for example, Yuen, L.-T., Zones, S. I., Harris, T. V., Gallegos, E. J., and Auroux, A., "Product Selectivity in Methanol to Hydrocarbon Conversion for Isostructural Compositions of API and CHA Molecular Sieves", Microporous Materials 2, 105-117 (1994) and Dahl, I. M., Mostad, H., Akporiaye, D., and Wendelbo, R., "Structural and Chemical Influences on the MTO Reaction: A Comparison of Chabazite and SAPO-34 as MTO Catalysts", Microporous and Mesoporous Materials 29, 185-190 (1999).
[0008] A silica crystalline molecular sieve having the CHA framework
type has been hydrothermally synthesized using
N,N,N-trimethyladamantylammonium in hydroxide form as the structure-directing agent at nearly neutral pH in the presence of fluoride. See Diaz-Cabanas, M-J, Barrett, P. A., and Camblor, M. A. "Synthesis and Structure of Pure SiO2 Chabazite: the SiO: Polymorph with the Lowest Framework Density", Chem. Commun. 1881 (1998).
[0009] More recently, an aluminosilicate with the CHA framework type
and having a silica to alumina molar ratio in excess of 100, such as from 150 to 2000, has been synthesized again in the presence of fluoride ions. See U.S. Patent
Application Publication No. 2003/0176751 published September 18, 2003 and incorporated herein by reference.
[0010] Molecular sieves of the AEI framework-type do not exist in nature.
However, a number of aluminophosphates and silicoaluminophosphates having the AEI framework type have been synthesized, including SAPO-18, ALPO-18 and RUW-18. In addition, U.S. Patent No. 5,958,370, incorporated herein by reference, discloses an aluminosilicate zeolite having an AEI framework-type and a silica to alumina molar ratio of 10 to 100. Aluminosilicates having a silica to alumina ratio greater than 100 and all-silica molecular sieves with an AEI framework-type have so far not been reported.
[0011] Regular crystalline molecular sieves, such as the AEI and CHA
framework types, are built from structurally invariant building units, called
Periodic Building Units, and are periodically ordered in three dimensions.
However, disordered structures showing periodic ordering in less than three
dimensions are also known. One such disordered structure is a disordered planar
intergrowth in which the repeated building units from more than one framework
type, e.g., both AEI and CHA, are present. In addition, for certain molecular
sieves, the building units can exist in mirror image forms, which can result in
stacking faults where a sequence of building units of one mirror image form
intersects a sequence of building units of the opposite mirror image form.
[0012] U.S. Patent No. 6,334,994, incorporated herein by reference,
discloses a silicoaluminophosphate molecular sieve, referred to as RUW-19, which is said to be an AE1/CHA mixed phase composition. In particular, RUW-19 is reported as having peaks characteristic of both CHA and AEI framework type molecular sieves, except that the broad feature centered at about 16.9 (26) in RUW-19 replaces the pair of reflections centered at about 17.0 (20) in AEI materials and RUW-19 does not have the reflections associated with CHA materials centered at 26 values of 17.8 and 24.8.
[0013] U.S. Patent Application Publication No. 2002/0165089, published
November 7, 2002 and incorporated herein by reference, discloses a silicoaluminophosphate molecular sieve comprising at least one intergrown phase of molecular sieves having AE1 and CHA framework types, wherein said
intergrown phase has an AEI/CHA ratio of from about 5/95 to 40/60 as
determined by DIFFaX analysis, using the powder X-ray diffraction pattern of a
calcined sample of said silicoaluminophosphate molecular sieve.
[0014] Phosphorus-free molecular sieves, such as aluminosilicates and
silicas, comprising CHA/AEI intergrowths have so far not been reported.
SUMMARY
[0015] In one aspect, the invention resides in a crystalline material
substantially free of framework phosphorus and comprising a CHA framework type molecular sieve with stacking faults or at least one intergrown phase of a CHA framework type molecular sieve and an AEI framework type molecular sieve, wherein said material, in its calcined, anhydrous form, has a composition involving the molar relationship:
(n)X203:Y02,
wherein X is a trivalent element, such as aluminum, boron, iron, indium, and/or
gallium; Y is a tetravalent element such as silicon, tin, titanium and/or
germanium; and n is from 0 to about 0.5, conveniently from 0 to about 0.125, for
example from about 0.001 to about 0.1, such as from about 0.0017 to about 0.02.
[0016] Conveniently, the calcined crystalline material contains from about
1 to about 100 ppm, for example from about 5 to about 50 ppm, such as from
about 10 to about 20 ppm, by weight of a halide, preferably fluoride.
[0017] In a further aspect, the invention resides in a crystalline material
which comprises at least a CHA framework type molecular sieve and which, in its
as-synthesized form, contains in its intra-molecular structure a first directing agent
for directing the synthesis of a CHA framework-type molecular sieve and a
second directing agent for directing the synthesis of a AEI framework-type
molecular sieve, said first and second directing agents being different.
|0018] In one embodiment, each of the first and second directing agents
comprises a cyclic amine or ammonium compound. More particularly, the first directing agent comprises a multi-cyclic amine or ammonium compound and the second directing agent comprises a monocyclic amine or ammonium compound. Conveniently, the multi-cyclic amine or ammonium compound comprises a
tricyclic or tetracyclic amine or ammonium compound, such as at least one of an N-alkyl-3-quinuclidinol, an N,N,N-trialkyl-exoaminonorbomane and an adamantylamine or ammonium compound, for example an N,N,N-trialkyl-l-adamantylammonium compound; typically an N,N,N-trimethyl-l-adamantylammonium compound. Conveniently, the monocyclic amine or ammonium compound comprises a substituted piperidine or piperidinium compound, for example a tetraalkylpiperidinium compound, typically an N,N-diethyl-2,6-dimethylpiperidinium compound.
J0019] In yet a further aspect, the invention resides in a method of
synthesizing a crystalline material comprising a CHA framework type molecular sieve and having a-composition involving the molar relationship:
(n)X203:Y02,
wherein X is a trivalent element, Y is a tetravalent element and n is from 0 to about 0.5, the method comprising:
(a) preparing a reaction mixture capable of forming said material, said
mixture comprising a source of water, a source of an oxide of a tetravalent
element Y, and optionally a source of an oxide of a trivalent element X;
(b) maintaining said reaction mixture under conditions sufficient to
form crystals of said crystalline material comprising stacking faults or at least one
intergrown phase of a CHA framework type molecular sieve and an AEI
framework type molecular sieve; and
(c) recovering said crystalline material from (b).
[0020] Conveniently, said reaction mixture also comprises a halide or a
halide-containing compound, such as a fluoride or a fluoride-containing
compound.
[0021] Conveniently, said reaction mixture also comprises a first directing
agent for directing the synthesis of a CHA framework-type molecular sieve and a
second directing agent for directing the synthesis of a AEI framework-type
molecular sieve.
[0022] Conveniently, said reaction mixture also comprises seed crystals.
The seed crystals can be homostructural or heterostructural with said intergrown
phase. In one embodiment, the seed crystals comprise a crystalline material having an AE1, CHA, OFF or LEV framework-type.
[0023] In still a further aspect, the invention resides in a process for
producing olefins comprising the step of contacting an organic oxygenate compound under oxygenate conversion conditions with a catalyst comprising a porous crystalline material substantially free of framework phosphorus and comprising at least one intergrown phase of a CHA framework type and an AEI framework type.
|0024] It is to be understood that the term "in its calcined, anhydrous
form" is used herein to refer to a material which has been heated in air at a temperature in excess of 400°C for 0.1 to 10 hours without allowing the material to rehydrate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figures la and Ib are DIFFaX simulated diffraction patterns for
intergrown CHA/AEI zeolite phases having varying CHA/AEI ratios.
[0026] Figure 2 is the X-ray diffraction pattern of the calcined product of
Example 1.
[0027] Figure 3 is an overlay of part of the X-ray diffraction pattern of
Figure 2 with the DIFFaX simulated trace obtained as the sum of 56% of phase
(a), a random intergrown AEI/CHA phase having an AE1/CHA ratio of 15/85, and
44% of phase (b), a random intergrown AEI/CHA phase having an AEI/CHA
ratio of 75/25. The weighted average AEI/CHA ratio for example 1 is calculated
as 41/59.
[0028] Figure 4 is a high resolution transmission electron micrograph of
the product of the 175°C synthesis of Example 2.
[0029] Figure 5 is a high resolution transmission electron micrograph of
the product of Example 3. The inset is a Fourier Transform of the high resolution
transmission electron micrograph.
[0030] Figure 6 is a bright-field transmission electron micrograph of the
product of Comparative Example 5.
[0031] Figure 7 is a bright-field transmission electron micrograph of the
natural chabazite of Comparative Example 6.
[0032] Figure 8 is the X-ray diffraction pattern of the calcined product of
Example 7.
[0033] Figure 9 is a high resolution transmission electron micrograph of
the product of Example 7.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0034] The present invention relates to a novel crystalline material that is
substantially free of framework phosphorus and that comprises a CHA framework type molecular sieve with stacking faults or at least one intergrown phase of a CHA framework type molecular sieve and an AEI framework type molecular sieve. The invention also relates to the synthesis of this novel crystalline material in a halide, and particularly a fluoride, medium and to use of the material, such as in a process for the conversion of oxygenates, particularly methanol, to olefms, particularly ethylene and propylene.
[0035] Intergrown molecular sieve phases are disordered planar
intergrowths of molecular sieve frameworks. Reference is directed to the "Catalog of Disordered Zeolite Structures", 2000 Edition, published by the Structure Commission of the International Zeolite Association and to the "Collection of Simulated XRD Powder Patterns for Zeolites", M. M. J. Treacy and J. B. Higgins, 2001 Edition, published on behalf of the Structure Commission of the International Zeolite Association for a detailed explanation on intergrown molecular sieve phases.
[0036] Regular crystalline solids are built from structurally invariant
building units, called Periodic Building Units, and are periodically ordered in three dimensions. Structurally disordered structures show periodic ordering in dimensions less than three, i.e. in two, one or zero dimensions. This phenomenon is called stacking disorder of structurally invariant Periodic Building Units. Crystal structures built from Periodic Building Units are called end-member structures if periodic ordering is achieved in all three dimensions. Disordered
structures are those where the stacking sequence of the Periodic Building Units
deviates from periodic ordering up to statistical stacking sequences.
[0037] In the case of regular AE] and CHA framework type molecular
sieves, the Periodic Building Unit is a double six ring layer. There are two types of layers "a" and "b", which are topologically identical except "b" is the mirror image of "a". When layers of the same type stack on top of one another, i.e. aaaaaaaa or bbbbbbbb, the framework type CHA is generated. When layers "a" and "b" alternate, ie, abababab, the framework type AEI is generated. Intergrown AEI/CHA molecular sieves comprise regions of CHA framework type sequences and regions of AEI framework type sequences. Each change from a CHA to an AEI framework type sequence results in a stacking fault. In addition, stacking faults can occur in a pure CHA phase material when a sequence of one mirror image layers intersects a sequence of the opposite mirror image layers, such as for example in aaaaaabbbbbbb.
[0038] Analysis of intergrown molecular sieves, such as AEI/CHA
intergrowths, can be effected by X-ray diffraction and in particular by comparing the observed patterns with calculated patterns generated using algorithms to simulate the effects of stacking disorder. DIFFaX is a computer program based on a mathematical model for calculating intensities from crystals containing planar faults (see M. M. J. Tracey et al., Proceedings of the Royal Chemical Society, London, A [1991], Vol. 433, pp. 499-520). DIFFaX is the simulation program selected by and available from the International Zeolite Association to simulate the XRD powder patterns for randomly intergrown phases of zeolites (see "Collection of Simulated XRD Powder Patterns for Zeolites" by M. M. J. Treacy and J. B. Higgins, 2001, Fourth Edition, published on behalf of the Structure Commission of the International Zeolite Association). It has also been used to theoretically study intergrown phases of AEI, CHA and KFI, as reported by K. P. Lillerud et al. in "Studies in Surface Science and Catalysis", 1994, Vol. 84, pp. 543-550.
|0039] Figures la and Ib show the simulated diffraction patterns
calculated by DIFFaX for single intergrown zeolite phases having various AEI/CHA ratios. These patterns were calculated using the input file given in
Table 1 below, with each pattern being normalized to the highest peak of the entire set of simulated patterns, i.e. the peak at about 9.6 degrees 28 for the 0/100 AEI/CHA pattern. Normalization of intensity values allows the intensity of an X-ray diffraction peak at a certain 26 value to be compared between different diffraction patterns.
[0040] Where the crystalline material of the invention comprises an
intergrowth of a CHA framework type molecular sieve and an AEI framework
type molecular sieve, the material can possess a widely varying AEI/CHA ratio of
from about 99:1 to about 1:99, such as from about 98:2 to about 2:98, for example
from about 95:5 to 5:95. In one embodiment, where the material is to be used a
catalyst in the conversion of oxygenates to olefins, the intergrowth is preferably
CHA-rich and has AEI/CHA ratio ranging from about 5:95 to about 30:70. In
addition, in some cases the intergrown material of the invention may comprise a
plurality of intergrown phases each having a different AEI/CHA ratio. The
relative amounts of AEI and CHA framework-type materials in the intergrowth of
the invention can be determined by a variety of known techniques including
transmission electron microscopy (TEM) and DIFFaX analysis, using the powder
X-ray diffraction pattern of a calcined sample of the molecular sieve.
[0041] Where the crystalline material of the invention comprises a CHA
framework type molecular sieve but with stacking faults, the presence of these stacking faults can readily be determined by transmission electron microscopy. It is to be appreciated that stacking faults may not be present in every crystal of the CHA material but generally will be present in at least 5%, such as at least 10%, of the crystals.
[0042] In its calcined and anhydrous form, the crystalline material of the
present invention has a composition involving the molar relationship:
(n)X203:Y02!
wherein X is a trivalent element, such as aluminum, boron, iron, indium, and/or gallium, typically aluminum; Y is a tetravalent element, such as silicon, tin, titanium and/or germanium, typically silicon; and n is from 0 to about 0.5, conveniently from 0 to about 0.125, for example from about 0.001 to about 0.1, such as from about 0.0017 to about 0.02. Where a halide-containing compound
has been used in the synthesis of the material, the calcined form of the material of
the present invention is normally found to contain trace amounts, typically from
about 1 to about 100 ppm, for example from about 5 to about 50 ppm, such as
from about 10 to about 20 ppm, by weight of the halide, preferably fluoride.
[0043] In its as-synthesized form, the crystalline material of the present
invention typically has a composition involving the molar relationship:
(n)X2O3:YO2:(m)R:(x)F:z H2O,
wherein X, Y and n are as defined in the preceding paragraph, R is at least one organic directing agent and wherein m ranges from about 0.01 to about 2, such as from about 0.1 to about 1, z ranges from about 0.5 to about 100, such as from about 2 to about 20 and x ranges from about 0 to about 2, such as from about 0.01 to about 1. The R and F components, which are associated with the material as a result of their presence during crystallization, can be at least partly removed by post-crystallization methods hereinafter more particularly described. Typically, in its as-synthesized form, the intergrowth of the present invention contains only low levels of alkali metal, generally such that the combined amount of any potassium and sodium is less than 50% of the X2C>3 on a molar basis. For this reason, after removal of the organic directing agent (R), the material generally exhibits catalytic activity without a preliminary ion-exchange step to remove alkali metal cations.
[0044] As will be discussed below, the least one organic directing agent
(R) typically comprises at least one first organic directing agent for directing the synthesis of a CHA framework-type material and at least one second organic directing agent for directing the synthesis of an AEI framework-type material. It is found that these directing agents are typically retained intact in the intramolecular structure of the molecular sieve product. Depending on the composition of the directing agents it will normally possible to determine the relative amounts of the different directing agents retained in the as-synthesized molecular sieve by analytical techniques, such as !3C MAS (magic-angle spinning) NMR. Thus, in a preferred embodiment, where the first organic directing agent is an N,N,N-trimethyl-l-adamantylammonium compound (TMAA) and the second organic directing agent is an N,N-diethyl-2,6-
dimethylpiperidinium compound (DEDMP), the DEDMP exhibits peaks corresponding to the C nuclei in the CHa moieties in the 0 to 20 ppm range of the 13C MAS NMR spectrum, which peaks are not present in the 13C MAS NMR spectrum of the TMAA. This, by measuring the peak heights in the 0 to 20 ppm range of the 13C MAS NMR spectrum, the relative amounts of TMAA and DEDMP in the as-synthesized material can be determined. Preferably, the molar amount of AEI directing agent retained in the as-synthesized material to the total molar amount of AEI and CHA directing agent retained in the as-synthesized material is between 0.1 and 0.3.
[0045] To the extent desired and depending on the X2O3/YO2 molar ratio
of the material, any cations in the as-synthesized intergrowth can be replaced in accordance with techniques well known in the art, at least in part, by ion exchange with other cations. Preferred replacing cations include metal ions, hydrogen ions, hydrogen precursor, e.g., ammonium ions, and mixtures thereof. Particularly preferred cations are those which tailor the catalytic activity for certain hydrocarbon conversion reactions. These include hydrogen, rare earth metals and metals of Groups IIA, IIIA, IV A, VA, IB, IIB, IIIB, IVB, VB, VIB, VIIB and VIII of the Periodic Table of the Elements.
[0046] The intergrowth of the invention can be prepared from a reaction
mixture containing a source of water, a source of an oxide of the tetravalent element Y, optionally a source of an oxide of the trivalent element X, at least one organic directing agent I as described below, and typically a halide or a halide-containing compound, such as a fluoride or a fluoride-containing compound, said reaction mixture having a composition, in terms of mole ratios of oxides, within the following ranges:

[0047] Where the tetravalent element Y is silicon, suitable sources of
silicon include silicates, e.g., tetraalkyl orthosilicates, fumed silica, such as Aerosil (available from Degussa), and aqueous colloidal suspensions of silica, for example that sold by E.I. du Pont de Nemours under the tradename Ludox. Where the trivalent element X is aluminum, suitable sources of aluminum include aluminum salts, especially water-soluble salts, such as aluminum nitrate, as well as hydrated aluminum oxides, such as boehmite and pseudoboehmite. Where the halide is fluoride, suitable sources of fluoride include hydrogen fluoride, although more benign sources of fluoride such as alkali metal fluorides and fluoride salts of the organic directing agent are preferred.
[0048] The at least one organic directing agent R used herein conveniently
comprises a mixture of a plurality of different organic directing agents. Preferably, the mixture comprises at least one first organic directing agent for directing the synthesis of a CHA framework-type material and at least one second organic directing agent for directing the synthesis of an AEI framework-type material.
[0049] Suitable first organic directing agents for directing the synthesis of
a CHA framework-type material include N,N,N-trimethyl-l-adamantammoniurn
compounds, N,N,N-trimethyl-2-adamantammonium compounds, N,N,N-
trimethylcyclohexylammonium compounds, N,N-dimethyl-3,3-
dimethylpiperidinium compounds, N,N-methylethyl-3,3-dimethylpiperidinium
compounds, N,N-dimethyl-2-methylpiperidinium compounds, 1,3,3,6,6-
pentamethyl-6-azonio-bicyclo(3,2.1)octane compounds, N,N-
dimethylcyclohexylamine, and the bi- and tri-cyclic nitrogen containing organic
compounds cited in (1) Zeolites and Related Microporous Materials: State of the
Art 1994, Studies of Surface Science and Catalysis, Vol. 84, p 29-36; in (2) Novel
Materials in Hetrogeneous Catalysis (ed. Terry K. Baker & Larry L. Murrell),
Chapter 2, p!4 - 24, May 1990, in (3) J. Am. Chem. Soc., 2000, 122, p 263-273
and (4) in U.S. Patent Nos. 4,544,538 and 6,709,644. Suitable compounds include
hydroxides and salts, such as halides, especially chlorides and fluorides.
|0050] Suitable second organic directing agents for directing the synthesis
of an AEI framework-type material include N,N-diethy]-2,6-dimethylpiperdinium

compounds (mixture or either of the cis/trans isomers), N,N-dimethyl-2,6-dimethylpiperdinium compounds (mixture or either of the cis/trans isomers), and the directing agents cited in J. Am. Chem. Soc., 2000, 122, p 263-273 and U.S. Patent No. 5,958,370.. Suitable compounds include hydroxides and salts, such as halides, especially chlorides and fluorides.
[0051] Conveniently, the molar ratio of the first organic directing agent to
the second organic directing agent in the reaction mixture is from about 0.01 to about 100, such as from about 0.02 to about 50, for example from about 0.03 to about 33, such as from about 0.03 to about 3, for example from about 0.05 to about 0.3.
[0052] In -one embodiment, the organic directing agent comprises a
mixture of cyclic amines or ammonium compounds, particularly a mixture where one component is a multi-cyclic amine or ammonium compound and more particularly a mixture where one component is a multi-cyclic amine or ammonium compound and another component is a monocyclic amine or ammonium compound. Conveniently, the monocyclic amine or ammonium compound comprises a substituted piperidine or piperidinium compound, for example a tetraalkylpiperidinium compound, typically an N,N-diethyl-2,6-dimethylpiperidinium compound. Conveniently, the multi-cyclic amine or ammonium compound comprises a tetracyclic amine or ammonium compound, such as an adamantylamine or ammonium compound, for example an N,N,N-trialkyl-1-adamantylammonium compound; typically an N,N,N-trimethyl-l-adamantylammonium compound. Thus the term multi-cyclic amine is used herein to include multi-cyclic compounds in which the N atom is external to the rings. Suitable ammonium compounds include hydroxides and salts, such as halides, especially chlorides.
[0053] Conveniently, the reaction mixture has a pH of about 4 to about 14,
such as about 4 to about 10, for example about 6 to about 8.
[0054] Crystallization can be carried out at either static or stirred
conditions in a suitable reactor vessel, such as for example, polypropylene jars or Teflon®-lined or stainless steel autoclaves, at a temperature of about 50°C to about 300°C, such as about 135°C to about 185°C, for a time sufficient for
crystallization to occur. Formation of the crystalline product can take anywhere from around 30 minutes up to as much as 2 weeks, such as from about 45 minutes to about 240 hours, for example from about 1.0 to about 120 hours. The duration depends on the temperature employed, with higher temperatures typically requiring shorter hydrothermal treatments.
[0055] Synthesis of the new intergrowth may be facilitated by the presence
of at least 0.1 ppm, such as at least 10 ppm, for example at least 100 ppm, conveniently at least 500 ppm of seed crystals based on total weight of the reaction mixture. The seed crystals can be homostructural with the crystalline material of the present invention, for example the product of a previous synthesis, or can be a heterostructural crystalline material, such as an AEI, LEV, OFF, CHA or ERI framework-type molecular sieve. Conveniently, the seed material is an AEI-type molecular sieve, and particularly an AEI-type aluminosilicate. The seeds may be added to the reaction mixture as a colloidal suspension in a liquid medium, such as water. The production of colloidal seed suspensions and their use in the synthesis of molecular sieves are disclosed in, for example, International Publication Nos. WO 00/06493 and WO 00/06494 published on February 10, 2000 and incorporated herein by reference.
[0056] Typically, the crystalline product is formed in solution and can be
recovered by standard means, such as by centrifugation or filtration. The separated product can also be washed, recovered by centrifugation or filtration and dried.
[0057] As a result of the crystallization process, the recovered crystalline
product contains within its pores at least a portion of the organic directing agent used in the synthesis. In a preferred embodiment, activation is performed in such a manner that the organic directing agent is removed from the molecular sieve, leaving active catalytic sites within the microporous channels of the molecular sieve open for contact with a feedstock. The activation process is typically accomplished by calcining, or essentially heating the molecular sieve comprising the template at a temperature of from about 200°C to about 800°C in the presence of an oxygen-containing gas. In some cases, it may be desirable to heat the molecular sieve in an environment having a low or zero oxygen concentration.
This type of process can be used for partial or complete removal of the organic
directing agent from the intracrystalline pore system. In other cases, particularly
with smaller organic directing agents, complete or partial removal from the sieve
can be accomplished by conventional desorption processes.
[0058] Once the intergrown crystalline material of the invention has been
synthesized, it can be formulated into a catalyst composition by combination with other materials, such as binders and/or matrix materials, that provide additional hardness or catalytic activity to the finished catalyst.
(0059] Materials which can be blended with the intergrown crystalline
material of the invention can be various inert or catalytically active materials.
These materials include compositions such as kaolin and other clays, various
forms of rare earth metals, other non-zeolite catalyst components, zeolite catalyst
components, alumina or alumina sol, titania, zirconia, quartz, silica or silica sol,
and mixtures thereof. These components are also effective in reducing overall
catalyst cost, acting as a thermal sink to assist in heat shielding the catalyst during
regeneration, densifying the catalyst and increasing catalyst strength. When
blended with such components, the amount of intergrown crystalline material
contained in the final catalyst product ranges from 10 to 90 weight percent of the
total catalyst, preferably 20 to 80 weight percent of the total catalyst.
[0060] The intergrown crystalline material described herein can be used to
dry gases and liquids; for selective molecular separation based on size and polar properties; as an ion-exchanger; as a chemical carrier; in gas chromatography; and as a catalyst in organic conversion reactions. Examples of suitable catalytic uses of the intergrown crystalline material described herein include (a) hydrocracking of heavy petroleum residual feedstocks, cyclic stocks and other hydrocrackate charge stocks, normally in the presence of a hydrogenation component selected from Groups 6 and 8 to 10 of the Periodic Table of Elements; (b) dewaxing, including isomerization dewaxing, to selectively remove straight chain paraffins from hydrocarbon feedstocks typically boiling above 177°C, including raffmates and lubricating oil basestocks; (c) catalytic cracking of hydrocarbon feedstocks, such as naphthas, gas oils and residual oils, normally in the presence of a large pore cracking catalyst, such as zeolite Y; (d) oligomerization of straight and
branched chain olefms having from about 2 to 21, preferably 2 to 5 carbon atoms, to produce medium to heavy olefms which are useful for both fuels, i.e., gasoline or a gasoline blending stock, and chemicals; (e) isomerization of olefms, particularly olefms having 4 to 6 carbon atoms, and especially normal butene to produce iso-olefins; (f) upgrading of lower alkanes, such as methane, to higher hydrocarbons, such as ethylene and benzene; (g) disproportionation of alkylaromatic hydrocarbons, such as toluene, to produce dialkylaromatic hydrocarbons, such as xylenes; (h) alkylation of aromatic hydrocarbons, such as benzene, with olefms, such as ethylene and propylene to produce ethylbenzene and cumene; (i) isomerization of dialkylaromatic hydrocarbons, such as xylenes, (j) catalytic reduction of nitrogen oxides and (k) synthesis of monoalkylamines and dialkylamines.
[0061] In particular, the intergrown crystalline material described herein is
useful as a catalyst in the conversion of oxygenates to one or more olefms, particularly ethylene and propylene. As used herein, the term "oxygenates" is defined to include, but is not necessarily limited to aliphatic alcohols, ethers, carbonyl compounds (aldehydes, ketones, carboxylic acids, carbonates, and the like), and also compounds containing hetero-atoms, such as, halides, mercaptans, sulfides, amines, and mixtures thereof. The aliphatic moiety will normally contain from about 1 to about 10 carbon atoms, such as from about 1 to about 4 carbon atoms.
[0062] Representative oxygenates include lower straight chain or branched
aliphatic alcohols, their unsaturated counterparts, and their nitrogen, halogen and sulfur analogues. Examples of suitable oxygenate compounds include methanol; ethanol; n-propanol; isopropanol; €4 - Cio alcohols; methyl ethyl ether; dimethyl ether; diethyl ether; di-isopropyl ether; methyl mercaptan; methyl sulfide; methyl amine; ethyl mercaptan; di-ethyl sulfide; di-ethyl amine; ethyl chloride; formaldehyde; di-methyl carbonate; di-methyl kelone; acetic acid; n-alkyl amines, n-alkyl halides, n-alkyl sulfides having n-alkyl groups of comprising the range of from about 3 to about 10 carbon atoms; and mixtures thereof. Particularly suitable oxygenate compounds are methanol, dimethyl ether, or mixtures thereof, most preferably methanol. As used herein, the term "oxygenate" designates only the
organic material used as the feed. The total charge of feed to the reaction zone may contain additional compounds, such as diluents.
[0063] In the present oxygenate conversion process, a feedstock
comprising an organic oxygenate, optionally with one or more diluents, is contacted in the vapor phase in a reaction zone with a catalyst comprising the molecular sieve of the present invention at effective process conditions so as to produce the desired olefins. Alternatively, the process may be carried out in a liquid or a mixed vapor/liquid phase. When the process is carried out in the liquid phase or a mixed vapor/liquid phase, different conversion rates and selectivities of feedstock-to-product may result depending upon the catalyst and the reaction conditions.
[0064] When present, the diluent(s) is generally non-reactive to the
feedstock or molecular sieve catalyst composition and is typically used to reduce the concentration of the oxygenate in the feedstock. Non-limiting examples of suitable diluents include helium, argon, nitrogen, carbon monoxide, carbon dioxide, water, essentially non-reactive paraffins (especially alkanes such as methane, ethane, and propane), essentially non-reactive aromatic compounds, and mixtures thereof. The most preferred diluents are water and nitrogen, with water being particularly preferred. Diluent(s) may comprise from about 1 mol % to about 99 mol % of the total feed mixture.
(0065] The temperature employed in the oxygenate conversion process
may vary over a wide range, such as from about 200°C to about 1000°C, for
example from about 250°C to about 800°C, including from about 250°C to about
750 °C, conveniently from about 300°C to about 650°C, typically from about
350°C to about 600°C and particularly from about 400°C to about 600°C.
[0066] Light olefin products will form, although not necessarily in
optimum amounts, at a wide range of pressures, including but not limited to autogenous pressures and pressures in the range of from about 0.1 kPa to about 10 MPa. Conveniently, the pressure is in the range of from about 7 kPa to about 5 MPa, such as in the range of from about 50 kPa to about 1 MPa. The foregoing pressures are exclusive of diluent, if any is present, and refer to the partial pressure of the feedstock as it relates to oxygenate compounds and/or mixtures
thereof. Lower and upper extremes of pressure may adversely affect selectivity, conversion, coking rate, and/or reaction rate; however, light olefins such as ethylene still may form.
J0067] The process should be continued for a period of time sufficient to
produce the desired olefin products. The reaction time may vary from tenths of seconds to a number of hours. The reaction time is largely determined by the reaction temperature, the pressure, the catalyst selected, the weight hourly space velocity, the phase (liquid or vapor) and the selected process design characteristics.
|0068] A wide range of weight hourly space velocities (WHSV) for the
feedstock will function in the present process. WHSV is defined as weight of feed (excluding diluent) per hour per weight of a total reaction volume of molecular sieve catalyst (excluding inerts and/or fillers). The WHSV generally should be in the range of from about 0.01 hr"1 to about 500 hr"1, such as in the range of from about 0.5 hr"1 to about 300 hr"1, for example in the range of from about 0.1 hr"1 to about 200 hr"1.
[0069] A practical embodiment of a reactor system for the oxygenate
conversion process is a circulating fluid bed reactor with continuous regeneration, similar to a modem fluid catalytic cracker. Fixed beds are generally not preferred for the process because oxygenate to olefin conversion is a highly exothermic process which requires several stages with intercoolers or other cooling devices. The reaction also results in a high pressure drop due to the production of low pressure, low density gas.
|0070] Because the catalyst must be regenerated frequently, the reactor
should allow easy removal of a portion of the catalyst to a regenerator, where the catalyst is subjected to a regeneration medium, such as a gas comprising oxygen, for example air, to burn off coke from the catalyst, which restores the catalyst activity. The conditions of temperature, oxygen partial pressure, and residence time in the regenerator should be selected to achieve a coke content on regenerated catalyst of less than about 0.5 wt %. At least a portion of the regenerated catalvst should be relumed to the reactor.
[0071] In one embodiment, prior to being used to convert oxygenate to
olefins, the catalyst is pretreated with dimethyl ether, a C2-C4 aldehyde composition and/or a C^-Ci olefm composition to form an integrated hydrocarbon co-catalyst within the porous framework of the intergrown molecular sieve. Desirably, the pretreatment is conducted at a temperature of at least 10°C, such as at least 25°C, for example at least 50°C, higher than the temperature used for the oxygenate reaction zone and is arranged to produce at least 0.1 wt%, such as at least lwt%, for example at least about 5wt% of the integrated hydrocarbon co-catalyst, based on total weight of the molecular sieve. Such preliminary treating to increase the carbon content of the molecular sieve is known as "pre-pooling" and is further described in U.S. Application Serial Nos. 10/712668, 10/712952 and 10/712953 all of which were filed November 12, 2003 and are incorporated herein by reference.
[0072] The invention will now be more particularly described with
reference to the following Examples and the accompanying drawings. In the Examples, the X-ray diffraction data were collected with several types of instruments:
• Philips XRD shall hereinafter refer to X-ray diffraction data collected with
a Philips powder X-Ray Diffractometer, equipped with a scintillation
detector with graphite monochromator, using copper K-alpha radiation.
The diffraction data were recorded by step-scanning at 0.02 degrees of
two-theta, where theta is the Bragg angle, and a counting time of 1 second
for each step. The interplanar spacings, d's, were calculated in Angstrom
units, and the relative intensities of the lines, I/I0, where I0 is the intensity
of the strongest line, above background were determined by integrating the
peak intensities.
• Synchrotron XRD shall hereinafter refer to powder X-ray diffraction data
collected at Brookhaven National Labs on beamline XI OB with a
monochromatic radiation wavelength of 0.8695 A using Debye-Scherrer
geometry. Samples were first calcined in air at 600°C for 3 hours to
remove the template. The calcined samples were then sealed in 2 mm
outside diameter quartz capillary tubes while out-gassing at 300 °C under
vacuum ( Scintag XRD shall hereinafter refer to X-ray diffraction data collected with a Scintag X2 X-Ray Diffractometer equipped with a Peltier-cooled solid state detector, using copper K-alpha radiation. The diffraction data were recorded by step-scanning at 0.02 degrees two-theta, where theta is the Bragg angle, and a counting time of 0.3 second for each step. The interplanar spacing, d's, were calculated in Angstrom units, and the relative intensities of the lines, l/lo, where lo is the intensity of the strongest line, above background were determined by integrating the peak intensities
J0073] X-ray diffraction data for the calcined samples was obtained by
subjecting the as-synthesized product to the following calcination procedure. About 2 grams of the as-synthesized product were heated from room temperature to 200°C under a flow of nitrogen at a rate of 2°C per minute. The temperature was held at 200°C for 30 minutes and then the sample was heated from 200°C to 650°C under nitrogen again at a rate of 2°C per minute. The sample was held at 650°C under nitrogen for 5-8 hours, whereafter the nitrogen was then replaced by air and the sample was kept at 650°C under air for 3 hours. The sample was then cooled to 200°C and kept at 200°C to prevent hydration. The hot sample was then transferred into the XRD sample cup and was covered by Mylar foil to prevent hydration.
|0074] DIFFaX analysis was used to determine the AEI/CHA ratio of the
molecular sieves. For DIFFaX analysis, powder XRD diffraction patterns for varying ratios of AEI/CHA were generated using the DIFFaX program available from the International Zeolite Association (see also M. M. J. Treacy et al.,
Proceedings of the Royal Chemical Society, London, A (1991), Vol. 433, pp. 499-520 "Collection of Simulated XRD Powder Patterns for Zeolites" by M. M. J. Treacy and J. B. Higgins, 2001, Fourth Edition, published on behalf of the Structure Commission of the International Zeolite Association). Table 1 gives the DIFFaX input file used to simulate the XRD diffraction pattern of a 50/50 inter-growth. For the purposes of this analysis, calculations were based on a random distribution of the layers. Such calculations are used for statistical purposes only, and do not mean that the true nature of the material is necessarily random.(O 2- 122 0 .18081 0 .34223 0 .06605 3 . 00 1 .0
0 2- 128 0 .81919 0 .34223 0 .06605 3 .00 1 .0
O 2- 114 0 .68081 0 .84223 0 .06605 3 .00 1 .0
0 2- 120 0 .31919 0 .84223 0 .06605 3 .00 1 .0
O 2- 98 0 .85329 0 .15098 0 .11991 3 .00 1 .0
0 2- 104 0 .14671 0 .15098 0 .11991 3 .00 1 .0
O 2- 106 0 .35329 0 .65098 0 .11991 3 .00 1 .0
O 2- 112 0 .64571 0 .65098 0 .11991 3 .00 1 .0
0 2- 58 0 .32516 0 .44369 0 .13307 3 .00 1 .0
0 2- 64 0. .67484 0 .44369 0, .13307 3 .00 1 .0
O 2- SO 0. .82516 0 .94369 0 .13307 3 .00 1 .0
0 2- 56 0 . .17484 0 .94369 0 .13307 3 .00 1 .0
O 2- 90 0. .00000 0. ,02575 0. .16208 3. .00 1 . .0
0 2- 94 0. .50000 0. ,52575 0, .16208 3, ,00 1 , .0
Si4 + 2 0. ,11783 0. .04597 0. .16618 1 , .50 1 , .0
Si4 + e 0. 88217 0. 04597 0. 16618 1. 50 1 . ,0
Si4 + 10 0 . 61783 0 . 54597 0. 16618 1. .50 1 . 0
Si4 + 16 0. 38217 0. 54597 0. 16618 1. .50 1 . 0
0 2- 130 0 . 15106 0. 06287 0. 25000 3. 00 1. 0
0 2- 131 0. 84894 0 . 06287 0. 25000 3. 00 1 . 0
O 2- 134 0. 65106 0. 56287 0. 25000 3. 00 1 . 0
0 2- 135 0. 34894 0 . 56287 0. 25000 3. 00 1. 0

STACKING
recursive
infinite
TRANSITIONS
{Transitions from layer l) 0.50 0.0 -0.0810 0.50 0.0 0.0

0.5 0.5

{Header for stacking description) (Statistical ensemble) (Infinite number of layers)
(Header for stacking transition data)
{layer 1 to layer 1: CHA-type cages) {layer 1 to layer 2: AEI-type cages)



(Transitions from layer 2} 0.50 0.0 0.0 0.5 0 . 50 0.0 0 .0810 0.5

(layer 2 to layer 1: AEI-type cages) (layer 2 to layer 2: CHA-type cages)

|0075] Figures la and Ib show the simulated diffraction patterns
calculated by DIFFaX for single intergrown zeolite phases having various AEI/CHA ratios, normalized to the highest peak of the entire set, i.e. the peak at about 9.6 29 for the 100% CHA case which was set to 100. The diffractograms were simulated using the following parameter settings: all Si AE]_CHA X=l.54056, PSEUDO-VO1GT 0.1 -0.036; line broadening: 0.009: 0.6. A non-

linear least-squares procedure ("DIFFaX Analysis") was then used to refine the contribution of one or more phases, and of the background and the 20 shift required to fit the experimental profile. An intergrowth sensitive region (see e.g. Figure 3) was always chosen in order to maximize the sensitivity of the calculations. Alternatively, a manual trial-and-error fit can be performed for identifying the type and magnitude of the contributing phases, the background counts and the 26 shift. For materials characterized by the presence of more than one intergrown phase, the contribution of AEI and CHA was calculated by a least squares analysis method, summing the AEI and CHA contribution of each intergrown phases. For Synchrotron XRDs, the comparison with the DIFFaX simulated patterns was done by converting the experimental XRD patterns to CuKal (X= 1.54056 A).
|0076] In addition, the 13C MAS (magic-angle spinning) NMR spectra
were obtained using a Chemagnetics® CMXII-200 spectrometer operating at a
static field of 4.7 T (199.9 MHz 'H, 50.3 MHz !3C). The as-synthesized samples
were loaded in MAS ZrOa NMR rotors (5-mm o.d.) and spun at the magic angle.
The 13C MAS NMR (or Bloch decay) experiments were performed using a
doubly-tuned probe by applying a (90°) 13C pulse followed by 13C data
acquisition. A !H-13C dipolar-decoupling field of about 62-kHz was used during
13C data acquisition. The 13C Bloch decay spectra were obtained at 8-kHz MAS
using a pulse delay of about 60-sec. The free-induction decays thus obtained were
Fourier transformed (with a 25 Hz exponential line broadening filter). The I3C
chemical shifts are referenced with respect to an external solution of tetramethyl
silane (TMS 6c = 0.0 ppm), using hexamethyl benzene as a secondary standard.
One or more of the none-overlapping regions can be taken and its relative
intensity determined. This can in turn be converted into mole ratio of the specific
template whereby the relative contribution of one template versus the other can be
calculated. All solid-state NMR measurements were done at room temperature.
|0077] TEM analysis included both Bright-Field TEM imaging (BF-TEM)
and High-Resolution TEM imaging (HR-TEM).

[0078] TEM data were obtained by crushing individual as-calcined
samples into fines ( [0079] HR-TEM data were obtained by embedding the calcined samplez
in LR White hard grade resin (The London Resin Co., UK). Then, without adding the curing accelerator; the resin was thermally cured at 80°C for at least 3 hours in a nitrogen atmosphere. Electron transparent thin sections were cut at ambient temperature using a Boeckeler Powertome XL ultra-microtome equipped with a diamond knife. The thin sections were collected on lacey carbon TEM grids. HR-TEM analysis was done in a Philips CM12T transmission electron microscope at an accelerating voltage of 120 kV. The crystals were carefully oriented with the appropriate zone axis parallel to the electron beam and high-resolution TEM images were recorded on photographic plate at a nominal magnification of 100,000x.
(Table Remove)

EXAMPLE 1
|0080] 0.286 ml of a 23.5 mg/ml aqueous solution of A1(N03)3-9H2O was
added to a mixture of 8.060 ml of an aqueous solution of N,N-diethyl-2,6-dimethylpiperidinium hydroxide, DEDMP* OH", (0.6008 molar) and 1.000 ml of an aqueous solution of N,N,N-tri-methyl-l-adamantylammonium hydroxide, TMAA4 OH", (0.5379 molar). 2.400 ml of tetraethylorthosilicate was then added to this composition and the resultant mixture was continuously stirred in a sealed container for at least 2-3 hours at room temperature until all the tetraethylorthosilicate was completely hydrolyzed. To the resultant clear solution was added 0.234 ml of a 48wt% aqueous solution of hydrofluoric acid which immediately resulted in the production of a slurry. This slurry was further homogenized by stirring and exposure to air for evaporation of water and ethanol until a thick slurry mixture was obtained. Extra water was further evaporated from the slurry mixture under static conditions to give 2672 mg of a dry gel solid having the following molar composition:
SiO2 : 0.00083A12O3 : 0.45DEDMP : 0.05TMAA : 0.6F : 5.0H2O
|0081] To this solid was added with mechanical mixing lOmg (0.37wt%
based on the dry gel solid) of a seeding material, AEI having a Si/Al atomic ratio of 8.9 and Si/Na atomic ratio of 26.4. The resulting mixture of solids was transferred to a Teflon®-lined 5 ml pressure reactor and crystallized at 150°C for 65 hours under slow rotation (about 60 rpm). After cooling, the resultant solid was recovered by centrifuging, washed with distilled water, and dried at 100°C to give 775 mg of a white microcrystalline solid (29.0% yield based on the weight of the dry gel). The as-synthesized product had the X-ray diffraction pattern summarized in Table 2 below. The calcined product had the Scintag X-ray diffraction pattern shown in Figure 2.
[0082] DIFFaX analysis was conducted on the X-ray pattern of Figure 2
and the results are summarized in Figure 3. Figure 3 shows that the product of Example 1 is characterized by the presence of more than one random intergrown AE1/CHA phase. Least squares analysis shows that the product of Example 1 is composed of about 56 wt% of a first intergrown AE1/CHA phase having an AE1/CHA ratio of 15/85 and about 44 wt% of a second intergrown AE1/CHA
phase having an Atl/LHA ratio oi /:>//:>, sucn mat me wcigmcu a AEI/CHA ratio of the material was about 41/59.
[0083] SEM analysis of the calcined product showed particles having a
thick plate morphology and a size of about 1-2 micron. Chemical analysis showed the silica/alumina molar ratio of the product to be 1200.
TABLE 2 - X-Ray Diffraction Pattern of As-Synthesized Product of Example 1
(Table Remove)
EXAMPLE 2
[0084] The synthesis of Example 1 was repeated in two separate
experiments using the same starting materials in the same proportions as Example 1 but with the crystallization temperatures being 135°C and 175°C respectively. DIFFaX analysis was conducted as described in example 1 on the Synchrotron X-ray diffraction pattern of the calcined product of the 175°C synthesis and showed the presence of two intergrown AEI7CHA phases, namely about 78wt% of a first
intergrown phase having an AE1/CHA ratio of 5/95 and and about 22 wt% of a second intergrown phase having an AE1/CHA ratio of 95/5, which corresponds to a weighted average AE1/CHA ratio of about 25/75.
|0085] 13C MAS NMR analysis of the product of the 175°C synthesis
showed the presence of DEDMP (the AEI directing agent) and TMAA (the CHA
directing agent) in a molar ratio of 50/50 in the as-synthesized product. This
contrasts with a DEDMP:TMAA molar ratio of 90/10 in the synthesis mixture.
[0086] A high resolution transmission electron micrograph of the product
of the 175°C synthesis is shown in Figure 4 and confirms the presence of twinned/faulted CHA crystals with intercalated regions of faulted AEI phase material.
EXAMPLE 3
[0087] The synthesis of Example 1 was repeated with the molar ratio of
DEDMP/TMAA in the synthesis mixture being 1.0. DIFFaX analysis on the Synchrotron X-ray diffraction pattern of the as-calcined product showed the product to be pure CHA. In addition, 13C MAS NMR analysis showed the presence of only TMAA (the CHAdirecting agent) in the as-synthesized product. A HR-TEM transmission electron micrograph of the product is shown in Figure 5. No presence of faulting is apparent in the HR-TEM image. The Fourier Transform of the HR-TEM image shows sharp spots and no streaks, which is indicative of a regular stacking and of the absence of stacking faults or twins. No faults were observed in the 500 chards produced for the TEM analysis.
EXAMPLE 4
[0088] The synthesis of Example 1 was repeated with the molar ratio of
DEDMP/TMAA in the synthesis mixture being 5.67 and the crystallization temperature being 175°C. DIFFaX analysis on the Synchrotron X-ray diffraction pattern of the as-calcined product showed the presence of three phases, namely about 73.5 wt% of a first intergrown phase having an AEI/CHA ratio of 5/95, about 5.2 wt% of a second intergrown phase having an AEI/CHA ratio of 90/10 and about 21.3 wt% of a third phase having an AEI/CHA ratio of 0/100, which
corresponds to a weighted average AEI/CHA ratio of about 8.5/91.5. 13C MAS NMR analysis showed the presence of DEDMP (the AEI directing agent) and TMAA (the CHA directing agent) in a molar ratio of 23/77 in the as-synthesized product.
EXAMPLE 5 (COMPARATIVE)
[0089] The process described in U.S. Patent No. 4,544,538 was repeated
to produce SSZ-13 as follows. 2.00 g IN NaOH, 2.78 g 0.72 molar N,N,N-
trimethyladamantammonium hydroxide, and 3.22 g deionized water were added
sequentially to a 23 ml Teflon lined Parr autoclave. To the resultant solution 0.05
g of aluminum hydroxide (Teheis F-2000 dried gel, 50% AljOs) was added and
the solution was mixed until it cleared. 0.60 g fumed silica (Cab-O-Sil, M5 grade,
97% SiOa) was then added to the autoclave and the solution was mixed until
uniform.
[0090] The autoclave was sealed and heated without agitation at 160°C for
4 days. The autoclave was then cooled to room temperature and the solid product
recovered by filtration. The product was washed repeatedly with deionized water
and then dried in a vacuum oven at 50°C.
[0091] X-ray diffraction analysis showed the product to be pure CHA
framework type molecular sieve. A transmission electron micrograph of the
product is shown in Figure 6. No presence of faulting is apparent in the TEM and
no faults were observed in the 500 chards produced for the TEM analysis.
EXAMPLE 6 (COMPARATIVE)
[0092] A sample of a light brown colored natural chabazite was obtained
from western US. It was analyzed to have Si/Al = 3.70, 0.28 wt% Na, 0.33wt% K, 0.03 wt% Ca, 0.28 wt% Mg, and 1.50 wt% Fe. The sample was subjected to transmission electron microscopy without any prior treatment and the results are shown in Figure 7. No presence of faulting was apparent in the BF-TEM and no faults were observed in the 500 chards produced for the BF-TEM analysis.
EXAMPLE 7
|0093] 0.239 ml of a 23.5 mg/ml aqueous solution of A1(NO3)3-9H2O was
added to a mixture of 5.597 ml of an aqueous solution of N,N-diethyl-2,6-dimethylpiperidinium hydroxide, DEDMP+ OH", (0.6008 molar) and 1.959 ml of an aqueous solution of N,N,N-tri-methyl-l-adamantylammoniurn hydroxide, TMAA* OH", (0.5721 molar). 2.000 ml of tetraethylorthosilicate was then added to this composition and the resultant mixture was continuously stirred in a sealed container for 15 hours at room temperature until all the tetraethylorthosilicate was completely hydrolyzed. To the resultant clear solution was added 0.195 ml of a 48wt% aqueous solution of hydrofluoric acid which immediately resulted in the production of a slurry. This slurry was further homogenized by stirring and exposure to air for evaporation of water and ethanol until a thick slurry mixture was obtained. To this thick slurry, 0.058ml (0.37wt.% based on the weight of the dry gel) of LEV colloidal seeds (SiO2/Al2O3=12) suspension slurry (14.1wt.%) containing 4478 wt. ppm of sodium and 18000 wt. ppm of potassium was added and stirring was continued for another 10 minutes. Extra water was further evaporated from the slurry mixture under static conditions to give 2242 mg of a dry gel solid having the following molar composition:
SiO2 : 0.00083A12O3: 0.375DEDMP : 0.125TMAA : 0.6F : 5.0H2O
[0094] The resulting mixture of solids was transferred to a Teflon®-lined 5
ml reactor and crystallized at 175°C for 65 hours under slow rotation (about 60
rpm). After cooling, the resultant solid was recovered by centrifuging, washed
with distilled water, and dried at 100°C to give 634 mg of a white microcrystalline
solid (28.3% yield based on the weight of the dry gel). The Synchrotron X-ray
diffraction pattern of as-synthesized product is shown in Table 3, whereas the X-
ray diffraction pattern of the as-calcined product is shown in Figure 8.
J0095] DIFFaX analysis on the calcined Synchrotron X-ray pattern of
Figure 8 suggests the material of Example 7 is a pure CHA phase material. However, 13C MAS NMR analysis showed the presence of DEDMP (the AEI directing agent) and TMAA (the CHA directing agent) in a molar ratio of 13/87 in the as-synthesized product. The HR-TEM of the product is shown in Figure 9 and
clearly shows the crystal is faulted. To quantify the amount of faulting, 500
chards were analyzed in BF-TEM and 10% of the chards showed faults.
|0096] 13C MAS NMR analysis showed the presence of DEDMP (the AEI
directing agent) and TMAA (the CHA directing agent) in a molar ratio of 13/87 in the as-synthesized product. SEM analysis of the calcined product showed particles having a thick plate morphology and a size of about 0.5 micron. Chemical analysis showed the silica/alumina molar ratio of the product to be 1200.
Table 3 - X-Ray Diffraction Pattern of As-Synthesized Product of Example 7
(Table Remove)
EXAMPLE 8
|0097] The as-synthesized materials from Examples 1 and 2 were
individually pressed to pellets at 30000 psig (2.07xl05 kPa) and then ground and sieved to between 80 and 125 fan. Two separate samples of each of the sized materials were weighed between 21 and 22 mg and mixed separately with 90 mg of 100 fjmn silicon carbide. These mixtures were loaded into separate 1.9mm internal diameter tubes sealed at the bottom with a quartz frit. The tubes were sealed into heated reactor blocks and the catalysts were then calcined at 540°C under flowing air for 2 hours to effect organic template removal. The calcined catalysts were then subjected to a mixture of 85% methanol in N2 at 500°C, approximately 100 weight hourly space velocity (WHSV), and 40 psia (276 kPa) methanol partial pressure for 25 minutes. During the methanol reactions the reactor effluents were collected and stored at timed intervals for analysis by gas chromatography. Following the methanol reaction the catalysts were subjected to a flow of 50% oxygen in nitrogen at 550°C for approximately 90 minutes to bum off deposited coke. The reactor effluents were analyzed by infrared spectroscopy with quantitation of both carbon monoxide and carbon dioxide to determine the amounts of coke deposition.
|0098] Selectivities to hydrocarbon products were calculated. The values
given below are averages of each individual selectivity over the entire reaction. Each value represents an average of the selectivities obtained from the two individual repeats.
Selectivity Crystallization Temperature (°C)

EXAMPLE 9
[0099] The synthesis of Example 3 was repeated with the molar ratio of
DEDMP/TMAA in the synthesis mixture varying between 0.33 and 19. The results of 13C MAS NMR analysis for detecting the presence of DEDMP (the AEI directing agent) and TMAA (the CHA directing agent), expressed in molar ratios, in the as-synthesized products, as well as the percentage of faulted chards observed in 500 chards by BF-TEM analysis are shown in the following table, together with the results for the as-synthesized material from Example 3.
(Table Remove)
[0100] The as-synthesized products of Example 9, together with the as-
synthesized material from Example 3, were individually pressed to pellets at 30000 psig (2.07xl05 kPa) and then ground and sieved to between 80 and 125 /im. Two separate samples of both of the sized materials were weighed between 21 and 22 mg and mixed separately with 90 mg of 100 /im silicon carbide. These mixtures were loaded into separate 1.9mm internal diameter tubes sealed at the bottom with a quartz frit. The tubes were sealed into heated reactor blocks and the catalysts were then calcined at 540°C under flowing air for 2 hours to effect organic template removal. The calcined catalysts were then subjected to a mixture of 85% methanol in Nj at 540°C, approximately 100 weight hourly space velocity (WHSV), and 40 psia (276 kPa) methanol partial pressure. During the methanol reactions the reactor effluents were collected and stored at timed intervals for analysis by gas chromatography. Following the methanol reaction the catalysts were subjected to a flow of 50% oxygen in nitrogen at 550°C for approximately 90 minutes to burn off deposited coke. The reactor effluents were analyzed by infrared spectroscopy with quantitation of both carbon monoxide and carbon dioxide to determine the amounts of coke deposition.

|0101] Selectivities to hydrocarbon products were calculated for each
reaction. The values given below are the individual point selectivities obtained 30 seconds after the start of the methanol reaction for each catalyst. These values represent the points of maximum olefin selectivity for each catalyst. Each value represents an average of the selectivities obtained from the two individual repeats.
Selectivity DEDMP/TMAA Ratio in Synthesis Gel
(Table Remove)
EXAMPLE 10
[0102] The as-synthesized material from Example 7 was pressed to a
pellet at 30000 psig (2.07x105 kPa) and then ground and sieved to between 80 and 125 //m. Two separate samples of the sized material were weighed between 21 and 22 mg and mixed separately with 90 mg of 100 pm silicon carbide. These mixtures were loaded into separate 1.9mm internal diameter tubes sealed at the bottom with a quartz frit. The tubes were sealed into heated reactor blocks and the catalysts were then calcined at 540°C under flowing air for 2 hours to effect organic template removal. The calcined catalysts were then subjected to a mixture of 85% methanol in N? at 540°C, approximately 100 weight hourly space velocity (WHSV), and 40 psia (276 kPa) methanol partial pressure for 25 minutes. During the methanol reaction the reactor effluents were collected and stored at timed intervals for analysis by gas chromatography. Following the methanol reaction the catalysts were subjected to a flow of 50% oxygen in nitrogen at 550°C for approximately 90 minutes to bum off deposited coke. The reactor effluents were
analyzed by infrared spectroscopy with quantitation of both carbon monoxide and
carbon dioxide to determine the amounts of coke deposition.
[0103] Selectivities to hydrocarbon products were calculated. The values
given below are averages of each individual selectivity over the entire reaction. Each value represents an average of the selectivities obtained from the two individual repeats.
[0104] While the present invention has been described and illustrated by
reference to particular embodiments, those of ordinary skill in the art will appreciate that the invention lends itself to variations not necessarily illustrated herein. For this reason, then, reference should be made solely to the appended claims for purposes of determining the true scope of the present invention.





WE CLAIM:
1. A crystalline material which, in its as-synthesized form, comprises at least a CHA framework type molecular sieve and an AEI framework-type molecular sieve, which, in its as-synthesized form, also contains in its intra-molecular structure a first directing agent for directing the synthesis of a CHA framework-type molecular sieve and a second directing agent for directing the synthesis of a AEI framework-type molecular sieve, said first and second directing agents being different.
2. The crystalline material as claimed in claim 1, wherein the first directing agent comprises at least one of an N-alkyl-3-quinuclidinol, an N,N,N-trialkyl-exoaminonorbornane, an N,N,N-trimethyl-l-adamantammonium compound, an N,N,N-trimethyl-2-adamantammonium compound, an N,N,N-trimethylcyclohexylammonium compound, an N,N-dimethyl-3,3-dimethylpiperidinium compound, an N,N-methylethyl-3,3-dimethylpiperidinium compound, an N,N-dimethyl-2-methylpiperidinium compound, a l,3,3,6,6-pentamethyl-6-azonio-bicyclo(3.2.1)octane compound and N,N-dimethylcyclohexylamine..
3. The crystalline material as claimed in claim 1, wherein the first directing agent comprises a multi-cyclic amine or ammonium compound.
4. The crystalline material as claimed in any one of claims 1 to 3, wherein the first directing agent comprises an N,N,N-trimethyl-l-adamantylammonium compound.
5. The crystalline material as claimed in any one of claims 1 to 4, wherein the second directing agent comprises a monocyclic amine or ammonium compound.
6. The crystalline material as claimed in any one of claims 1 to 5, wherein the second directing agent comprises an N,N-dimethyl-2,6-dimethylpiperidinium compound or an N,N-diethyl-2,6-dimethylpiperidinium compound.
7. The crystalline material as claimed in any one of claims 1 to 6, wherein the molar amount of second directing agent retained in the as-synthesized material to the total molar
amount of first and second directing agents retained in the as-synthesized material is between 0.1 and 0.3.

Documents:

2626-delnp-2006-Abstract-(22-06-2011).pdf

2626-DELNP-2006-Abstract-(23-01-2012).pdf

2626-delnp-2006-abstract.pdf

2626-delnp-2006-assignments.pdf

2626-delnp-2006-Claims-(22-06-2011).pdf

2626-DELNP-2006-Claims-(23-01-2012).pdf

2626-delnp-2006-claims.pdf

2626-delnp-2006-Correspondence Others-(22-06-2011).pdf

2626-DELNP-2006-Correspondence Others-(23-01-2012).pdf

2626-delnp-2006-correspondence-others 1.pdf

2626-delnp-2006-Description (Complete)-(22-06-2011).pdf

2626-DELNP-2006-Description (Complete)-(23-01-2012).pdf

2626-delnp-2006-description (complete).pdf

2626-delnp-2006-Drawings-(22-06-2011).pdf

2626-delnp-2006-drawings.pdf

2626-delnp-2006-Form-1-(22-06-2011).pdf

2626-DELNP-2006-Form-1-(23-01-2012).pdf

2626-delnp-2006-form-1.pdf

2626-delnp-2006-form-18.pdf

2626-delnp-2006-Form-2-(22-06-2011).pdf

2626-DELNP-2006-Form-2-(23-01-2012).pdf

2626-delnp-2006-form-2.pdf

2626-delnp-2006-Form-3-(22-06-2011).pdf

2626-delnp-2006-form-3.pdf

2626-delnp-2006-form-5.pdf

2626-delnp-2006-GPA-(22-06-2011).pdf

2626-delnp-2006-gpa.pdf

2626-delnp-2006-pct-206.pdf

2626-delnp-2006-pct-220.pdf

2626-delnp-2006-pct-304.pdf

2626-delnp-2006-pct-409.pdf

2626-delnp-2006-pct-416.pdf

2626-delnp-2006-pct-request form.pdf

2626-delnp-2006-pct-search report.pdf

2626-delnp-2006-Petition-137-(22-06-2011).pdf


Patent Number 251405
Indian Patent Application Number 2626/DELNP/2006
PG Journal Number 11/2012
Publication Date 16-Mar-2012
Grant Date 12-Mar-2012
Date of Filing 10-May-2006
Name of Patentee EXXONMOBIL CHEMICAL PATENTS INC
Applicant Address 5200 BAYWAY DRIVE BAYTOWN TEXAS 77520-2101,UNITED STATES OF AMERICA
Inventors:
# Inventor's Name Inventor's Address
1 HAILIAN LI 130 PASITO TERRACE APT 409 SUNNYVALE CA 94086 USA
2 ANIL S.GURAM 1044 ARLINGTON LANE SAN JOSE CA 95129, USA
3 MARK T.MURAOKA 2047 MONTECITO AVENUE #5 MOUNTAIN VIEW CA 94043,USA
4 GUANG CAO 528 WOODSIDE LANE BRANCHBURG,NJ 08876,USA
5 MACHTELD M.MERTENS BERINGSTRAAT 72,B-3190 BOORTMEERBEEK BELGIUM
6 KARL G.STROHMAIER 47 ROCKPORT ROAD PORT MURRAY NJ 07865 USA
7 RICHARD B.HALL 40 HOLLAND BROOK ROAD WHITEHOUSE STATION NJ 08889 USA
8 THOMAS H.COLLE 2319 SYCAMORE GROVE,HOUSTON,TX 77062 USA
9 MOBAE AFEWORKI 807 MARY CIRCLE STEWARTSVILLE NJ 08886 USA
10 ANTONIE JAN BONS EDELZANGERSLAAN 1, B-3010 KESSEL-LO BELGIUM
11 WILFRIED J.MORTIER DIESTSE STEENWEG 483 B-3010 KESSEL -LO BELGIUM
12 CHRIS KLIEWER 5 AUSTIN HILL ROAD CLINTON NJ 08809 USA
13 ROBERT J.SAXTON 5168 INDEPENDENDENCE DRIVE PLEASANTON CA 94566 USA
14 JEFFREY C.YODER 5401 MARY JO WAY SAN JOSE CA 95124 USA
PCT International Classification Number CO1B 39/00
PCT International Application Number PCT/US2004/042739
PCT International Filing date 2004-12-20
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 60/532,600 2003-12-23 U.S.A.