U.S. patent application number 10/186905 was filed with the patent office on 2004-01-08 for zeolite ssz-54 composition of matter and synthesis thereof.
Invention is credited to Burton, Allen W. JR., Zones, Stacey.
Application Number | 20040005271 10/186905 |
Document ID | / |
Family ID | 29779962 |
Filed Date | 2004-01-08 |
United States Patent
Application |
20040005271 |
Kind Code |
A1 |
Zones, Stacey ; et
al. |
January 8, 2004 |
ZEOLITE SSZ-54 COMPOSITION OF MATTER AND SYNTHESIS THEREOF
Abstract
The present invention relates to new crystalline zeolite SSZ-54
prepared using a templating agent comprising N-isopropyl
ethylenediamine, or a mixture of 1-N-isopropyl diethylenetriamine
and isobutylamine, and processes employing SSZ-54 in a
catalyst.
Inventors: |
Zones, Stacey; (San
Francisco, CA) ; Burton, Allen W. JR.; (Richmond,
CA) |
Correspondence
Address: |
Richard J. Sheridan
Chevron Texaco Corporation
P.O. Box 6006
San Ramon
CA
94583-0806
US
|
Family ID: |
29779962 |
Appl. No.: |
10/186905 |
Filed: |
June 28, 2002 |
Current U.S.
Class: |
423/705 ;
423/706; 423/708; 423/718 |
Current CPC
Class: |
C01B 37/02 20130101;
C01B 39/48 20130101; Y10S 423/35 20130101; C01B 39/12 20130101;
Y10S 423/36 20130101 |
Class at
Publication: |
423/705 ;
423/706; 423/708; 423/718 |
International
Class: |
C01B 039/48 |
Claims
What is claimed is:
1. A zeolite having a mole ratio greater than about 20 of an oxide
of a first tetravalent element to an oxide of a second tetravalent
element which is different from said first tetravalent element,
trivalent element, pentavalent element or mixture thereof and
having, after calcination, the X-ray diffraction pattern of FIG.
1.
2. A zeolite having a mole ratio greater than about 20 of an oxide
selected from the group consisting of silicon oxide, germanium
oxide and mixtures thereof to an oxide selected from aluminum
oxide, gallium oxide, iron oxide, boron oxide, titanium oxide,
indium oxide, vanadium oxide and mixtures thereof, and having,
after calcination, the X-ray diffraction pattern of FIG. 1.
3. A zeolite according to claim 2 wherein the oxides comprise
silicon oxide and aluminum oxide.
4. A zeolite according to claim 2 wherein the oxides comprise
silicon oxide and boron oxide.
5. A zeolite according to claim 1 wherein said zeolite is
predominantly in the hydrogen form.
6. A zeolite according to claim 1 wherein said zeolite is
substantially free of acidity.
7. A zeolite having a composition, as synthesized and in the
anhydrous state, in terms of mole ratios as follows:
7 YO.sub.2/W.sub.cO.sub.d 25-100 M.sub.2/n/YO.sub.2 0.02-0.06
Q/YO.sub.2 0.01-0.04
wherein Y is silicon, germanium or a mixture thereof; W is
aluminum, gallium, iron, boron, titanium, indium, vanadium or
mixtures thereof; c is 1 or 2; d is 2 when c is 1 or d is 3 or 5
when c is 2; M is an alkali metal cation, alkaline earth metal
cation or mixtures thereof; n is the valence of M; and Q comprises
N-isopropyl ethylenediamine, or a mixture of 1-N-isopropyl
diethylenetriamine and isobutylamine.
8. A zeolite according to claim 7 wherein W is aluminum and Y is
silicon.
9. A zeolite according to claim 7 wherein W is boron and Y is
silicon.
10. A zeolite according to claim 7 wherein Q is N-isopropyl
ethylenediamine.
11. A zeolite according to claim 7 wherein Q is a mixture of
1-N-isopropyl diethylenetriamine and isobutylamine.
12. A method of preparing a crystalline material comprising an
oxide of a first tetravalent element and an oxide of a second
tetravalent element which is different from said first tetravalent
element, trivalent element, pentavalent element or mixture thereof,
said method comprising contacting under crystallization conditions
sources of said oxides and a templating agent comprising
N-isopropyl ethylenediamine, or a mixture of 1-N-isopropyl
diethylenetriamine and isobutylamine.
13. The method according to claim 12 wherein the first tetravalent
element is selected from the group consisting of silicon, germanium
and combinations thereof.
14. The method according to claim 12 wherein the second tetravalent
element, trivalent element or pentavalent element is selected from
the group consisting of aluminum, gallium, iron, boron, titanium,
indium, vanadium and combinations thereof.
15. The method according to claim 14 wherein the second tetravalent
element or trivalent element is selected from the group consisting
of aluminum, boron, titanium and combinations thereof.
16. The method according to claim 15 wherein the first tetravalent
element is silicon.
17. The method according to claim 12 wherein the templating agent
is N-isopropyl ethylenediamine.
18. The method according to claim 12 wherein the templating agent
is a mixture of 1-N-isopropyl diethylenetriamine and
isobutylamine.
19. The method of claim 12 wherein the crystalline material has,
after calcination, the X-ray diffraction pattern of FIG. 1.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to new crystalline zeolite
SSZ-54, a method for preparing SSZ-54 using a templating agent
comprising N-isopropyl ethylenediamine, or a mixture of
1-N-isopropyl diethylenetriamine and isobutylamine, and processes
employing SSZ-54 in a catalyst.
[0003] 2. State of the Art
[0004] Because of their unique sieving characteristics, as well as
their catalytic properties, crystalline molecular sieves and
zeolites are especially useful in applications such as hydrocarbon
conversion, gas drying and separation. Although many different
crystalline molecular sieves have been disclosed, there is a
continuing need for new zeolites with desirable properties for gas
separation and drying, hydrocarbon and chemical conversions, and
other applications. New zeolites may contain novel internal pore
architectures, providing enhanced selectivities in these
processes.
[0005] Crystalline aluminosilicates are usually prepared from
aqueous reaction mixtures containing alkali or alkaline earth metal
oxides, silica, and alumina. Crystalline borosilicates are usually
prepared under similar reaction conditions except that boron is
used in place of aluminum. By varying the synthesis conditions and
the composition of the reaction mixture, different zeolites can
often be formed.
SUMMARY OF THE INVENTION
[0006] The present invention is directed to a family of crystalline
molecular sieves with unique properties, referred to herein as
"zeolite SSZ-54" or simply "SSZ-54". Preferably, SSZ-54 is obtained
in its silicate, aluminosilicate, titanosilicate, vanadosilicate or
borosilicate form. The term "silicate" refers to a zeolite having a
high mole ratio of silicon oxide relative to aluminum oxide,
preferably a mole ratio greater than 100, including zeolites
composed entirely of silicon oxide. As used herein, the term
"aluminosilicate" refers to a zeolite containing both alumina and
silica and the term "borosilicate" refers to a zeolite containing
oxides of both boron and silicon.
[0007] In accordance with this invention, there is provided a
zeolite having a mole ratio greater than about 20 of an oxide of a
first tetravalent element to an oxide of a second tetravalent
element different from said first tetravalent element, trivalent
element, pentavalent element or mixture thereof and having, after
calcination, the X-ray diffraction pattern of FIG. 1.
[0008] Further, in accordance with this invention, there is
provided a zeolite having a mole ratio greater than about 20 of an
oxide selected from silicon oxide, germanium oxide and mixtures
thereof to an oxide selected from aluminum oxide, gallium oxide,
iron oxide, boron oxide, titanium oxide, indium oxide, vanadium
oxide and mixtures thereof and having, after calcination, the X-ray
diffraction pattern of FIG. 1.
[0009] The present invention further provides such a zeolite having
a composition, as synthesized and in the anhydrous state, in terms
of mole ratios as follows:
1 YO.sub.2/W.sub.cO.sub.d 25-100 M.sub.2/n/YO.sub.2 0.02-0.06
Q/YO.sub.2 0.01-0.04
[0010] wherein Y is silicon, germanium or a mixture thereof; W is
aluminum, gallium, iron, boron, titanium, indium, vanadium or
mixtures thereof; c is 1 or 2; d is 2 when c is 1 (i.e., W is
tetravalent) or d is 3 or 5 when c is 2 (i.e., d is 3 when W is
trivalent or 5 when W is pentavalent); M is an alkali metal cation,
alkaline earth metal cation or mixtures thereof (M is preferably
potassium); n is the valence of M (i.e., 1 or 2); and Q is
N-isopropyl ethylenediamine, or a mixture of 1-N-isopropyl
diethylenetriamine and isobutylamine.
[0011] In accordance with this invention, there is also provided a
zeolite prepared by thermally treating a zeolite having a mole
ratio of an oxide selected from silicon oxide, germanium oxide and
mixtures thereof to an oxide selected from aluminum oxide, gallium
oxide, iron oxide, boron oxide, titanium oxide, indium oxide,
vanadium oxide and mixtures thereof greater than about 20 at a
temperature of from about 200.degree. C. to about 800.degree. C.,
the thus-prepared zeolite having the X-ray diffraction pattern of
FIG. 1. The present invention also includes this thus-prepared
zeolite which is predominantly in the hydrogen form, which hydrogen
form is prepared by ion exchanging with an acid or with a solution
of an ammonium salt followed by a second calcination.
[0012] Also provided in accordance with the present invention is a
method of preparing a crystalline material comprising an oxide of a
first tetravalent element and an oxide of a second tetravalent
element which is different from said first tetravalent element,
trivalent element, pentavalent element or mixture thereof, said
method comprising contacting under crystallization conditions
sources of said oxides and a templating agent comprising
N-isopropyl ethylenediamine, or a mixture of 1-N-isopropyl
diethylenetriamine and isobutylamine.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is an X-ray diffraction pattern of a calcined sample
of SSZ-54.
[0014] FIG. 2 is an X-ray diffraction pattern of a calcined sample
of a zeolite having the MTT crystal structure.
[0015] FIG. 3 is an X-ray diffraction pattern of a calcined sample
of a zeolite having the TON crystal structure.
[0016] FIG. 4 shows calculated X-ray patterns of calcined zeolites
having about 50%, 60%, 70% or 80% MTT crystal structure and the
balance the TON crystal structure. For comparison purposes, FIG. 4
also shows the X-ray diffraction pattern for SSZ-54.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The present invention comprises a family of crystalline,
medium pore zeolites designated herein "zeolite SSZ-54" or simply
"SSZ-54". As used herein, the term "medium pore" means having an
average pore size diameter greater than about 4.5-6 Angstroms.
[0018] While not wishing to be bound by any particular theory, it
is believed that SSZ-54 is an intergrowth of the MTT and TON
crystal structures. FIG. 1 shows the X-ray diffraction pattern of a
calcined sample of SSZ-54. FIG. 2 shows the X-ray diffraction
pattern of a calcined sample of a pure phase zeolite having the MTT
crystal structure, and FIG. 3 shows the X-ray diffraction pattern
of a calcined sample of a pure phase zeolite having the TON crystal
structure. It can be seen that there are similarities between the
pattern for SSZ-54 and the patterns for MTT and TON.
[0019] FIG. 4 shows calculated X-ray diffraction patterns for
zeolites that are an intergrowth of the MTT and TON crystal
structures. The calculated patterns are for intergrowths containing
about 50%, 60%, 70% and 80% MTT and about 50%, 40%, 30% and 20%
TON, respectively. FIG. 4 also shows the X-ray diffraction pattern
for SSZ-54. It can be seen that there is a reasonably good
correlation between the calculated pattern of 70% MTT/30% TON and
the SSZ-54 pattern.
[0020] It is further believed that the peak broadening seen in the
SSZ-54 pattern of FIG. 4 is due to disorder in the SSZ-54 crystal
structure rather than exclusively to small crystal size. This is
further evidence that SSZ-54 is an intergrowth of more than one
crystal structure.
[0021] When needle-like crystals of SSZ-54 were examined by TEM,
the cross-section showed TON and MTT domains within the same
crystal. This is further evidence that SSZ-54 is an intergrowth of
TON and MTT crystal structures.
[0022] After calcination, the SSZ-54 has a crystalline structure
whose X-ray powder diffraction pattern includes the characteristic
lines shown in Table I below.
2TABLE I Calcined SSZ-54 Two Theta (deg.).sup.(a) Relative
Intensity 8.06 VS 8.78 W 11.32 W 15.82 W 16.28 W 17,97 W 19.64 S-VS
20.68 VS 22.92 W-M 24.00 VS 24.5 VS 25.94 M 31.76 W 35.48 M 36.62 W
37.65 W .sup.(a).+-. 0.2
[0023] .sup.(b) The X-ray patterns provided are based on a relative
intensity scale in which the strongest line in the X-ray pattern is
assigned a value of 100: W(weak) is less than 20; M(medium) is
between 20 and 40; S(strong) is between 40 and 60; VS(very strong)
is greater than 60.
3TABLE IA Calcined SSZ-54 Two Theta (deg.).sup.(a) Relative
Intensity 8.06 68 8.78 10 11.32 17 15.82 8 16.28 4 17,97 1 19.64 58
20.68 77 22.92 19 24.00 90 24.5 100 25.94 28 31.76 18 35.48 23
36.62 13 37.65 4
[0024] In preparing SSZ-54 zeolites, N-isopropyl ethylenediamine,
or a mixture of 1-N-isopropyl diethylenetriamine and isobutylamine
is used as a crystallization template (sometimes called a structure
directing agent). In general, SSZ-54 is prepared by contacting an
active source of one or more oxides selected from the group
consisting of monovalent element oxides, divalent element oxides,
trivalent element oxides, and tetravalent element oxides with the
templating agent.
[0025] The templating agents of this invention have the following
chemical structures: 1
[0026] When the templating agent is a mixture of 1-N-isopropyl
diethylenetriamine and isobutylamine, the mole ratio of
1-N-isopropyl diethylenetriamine to isobutylamine may be about
1:8.
[0027] SSZ-54 is prepared from a reaction mixture having the
composition shown in Table A below.
4TABLE A Reaction Mixture Typical Preferred YO.sub.2/W.sub.aO.sub.b
25-100 30-70 OH--/YO.sub.2 0.15-0.50 0.20-0.30 Q/YO.sub.2 0.10-1.00
0.10-0.40 M.sub.2/n/YO.sub.2 0.03-0.20 0.05-0.15 H.sub.2O/YO.sub.2
10-75 15-40
[0028] where Y, W, Q, M and n are as defined above, and a is 1 or
2, and b is 2 when a is 1 (i.e., W is tetravalent) and b is 3 when
a is 2 (i.e., W is trivalent).
[0029] In practice, SSZ-54 is prepared by a process comprising:
[0030] (a) preparing an aqueous solution containing sources of at
least one oxide capable of forming a crystalline molecular sieve
and the templating agent of this invention;
[0031] (b) maintaining the aqueous solution under conditions
sufficient to form crystals of SSZ-54; and
[0032] (c) recovering the crystals of SSZ-54.
[0033] Accordingly, SSZ-54 may comprise the crystalline material
and the templating agent in combination with metallic and
non-metallic oxides bonded in tetrahedral coordination through
shared oxygen atoms to form a cross-linked three dimensional
crystal structure. The metallic and non-metallic oxides comprise
one or a combination of oxides of a first tetravalent element(s),
and one or a combination of a second tetravalent element(s)
different from the first tetravalent element(s), trivalent
element(s), pentavalent element(s) or mixture thereof. The first
tetravalent element(s) is preferably selected from the group
consisting of silicon, germanium and combinations thereof. More
preferably, the first tetravalent element is silicon. The second
tetravalent element (which is different from the first tetravalent
element), trivalent element and pentavalent element is preferably
selected from the group consisting of aluminum, gallium, iron,
boron, titanium, indium, vanadium and combinations thereof. More
preferably, the second trivalent or tetravalent element is aluminum
or boron.
[0034] Typical sources of aluminum oxide for the reaction mixture
include aluminates, alumina, aluminum colloids, aluminum oxide
coated on silica sol, hydrated alumina gels such as Al(OH).sub.3
and aluminum compounds such as AlCl.sub.3 and
Al.sub.2(SO.sub.4).sub.3. Typical sources of silicon oxide include
silicates, silica hydrogel, silicic acid, fumed silica, colloidal
silica, tetra-alkyl orthosilicates, and silica hydroxides. Boron,
as well as gallium, germanium, titanium, indium, vanadium and iron,
can be added in forms corresponding to their aluminum and silicon
counterparts.
[0035] A source zeolite reagent may provide a source of aluminum or
boron. In most cases, the source zeolite also provides a source of
silica. The source zeolite in its dealuminated or deboronated form
may also be used as a source of silica, with additional silicon
added using, for example, the conventional sources listed above.
Use of a source zeolite reagent as a source of alumina for the
present process is more completely described in U.S. Pat. No.
5,225,179, issued Jul. 6, 1993 to Nakagawa entitled "Method of
Making Molecular Sieves", the disclosure of which is incorporated
herein by reference.
[0036] Typically, an alkali metal hydroxide and/or an alkaline
earth metal hydroxide, such as the hydroxide of sodium, potassium,
lithium, cesium, rubidium, calcium, and magnesium, is used in the
reaction mixture; however, this component can be omitted so long as
the equivalent basicity is maintained. The templating agent may be
used to provide hydroxide ion. Thus, it may be beneficial to ion
exchange, for example, the halide for hydroxide ion, thereby
reducing or eliminating the alkali metal hydroxide quantity
required. The alkali metal cation or alkaline earth cation may be
part of the as-synthesized crystalline oxide material, in order to
balance valence electron charges therein.
[0037] The reaction mixture is maintained at an elevated
temperature until the crystals of the SSZ-54 zeolite are formed.
The hydrothermal crystallization is usually conducted under
autogenous pressure, at a temperature between 100.degree. C. and
200.degree. C., preferably between 135.degree. C. and 160.degree.
C. The crystallization period is typically greater than 1 day and
preferably from about 3 days to about 20 days.
[0038] Preferably, the zeolite is prepared using mild stirring or
agitation.
[0039] During the hydrothermal crystallization step, the SSZ-54
crystals can be allowed to nucleate spontaneously from the reaction
mixture. The use of SSZ-54 crystals as seed material can be
advantageous in decreasing the time necessary for complete
crystallization to occur. In addition, seeding can lead to an
increased purity of the product obtained by promoting the
nucleation and/or formation of SSZ-54 over any undesired phases.
When used as seeds, SSZ-54 crystals are added in an amount between
0.1 and 10% of the weight of silica used in the reaction
mixture.
[0040] Once the zeolite crystals have formed, the solid product is
separated from the reaction mixture by standard mechanical
separation techniques such as filtration. The crystals are
water-washed and then dried, e.g., at 90.degree. C. to 150.degree.
C. for from 8 to 24 hours, to obtain the as-synthesized SSZ-54
zeolite crystals. The drying step can be performed at atmospheric
pressure or under vacuum.
[0041] SSZ-54 as prepared has a mole ratio of an oxide selected
from silicon oxide, germanium oxide and mixtures thereof to an
oxide selected from aluminum oxide, gallium oxide, iron oxide,
boron oxide, titanium oxide, indium oxide, vanadium oxide and
mixtures thereof greater than about 20; and has, after calcination,
the X-ray diffraction pattern of FIG. 1. SSZ-54 further has a
composition, as synthesized (i.e., prior to removal of the
templating agent from the zeolite) and in the anhydrous state, in
terms of mole ratios, shown in Table B below.
5TABLE B As-Synthesized SSZ-54 YO.sub.2/W.sub.cO.sub.d 25-100
M.sub.2/n/YO.sub.2 0.02-0.06 Q/YO.sub.2 0.01-0.04
[0042] where Y, W, c, d, M, n and Q are as defined above.
[0043] SSZ-54 can be made essentially aluminum free, i.e., having a
silica to alumina mole ratio of .infin.. A method of increasing the
mole ratio of silica to alumina is by using standard acid leaching
or chelating treatments. However, essentially aluminum-free SSZ-54
can be synthesized directly using essentially aluminum-free silicon
sources as the main tetrahedral metal oxide component, if boron is
also present. SSZ-54 can also be prepared directly as either an
aluminosilicate or a borosilicate.
[0044] Lower silica to alumina ratios may also be obtained by using
methods which insert aluminum into the crystalline framework. For
example, aluminum insertion may occur by thermal treatment of the
zeolite in combination with an alumina binder or dissolved source
of alumina. Such procedures are described in U.S. Pat. No.
4,559,315, issued on Dec. 17, 1985 to Chang et al.
[0045] It is believed that SSZ-54 is comprised of a new framework
structure or topology which is characterized by its X-ray
diffraction pattern. After calcination, the SSZ-54 zeolites have a
crystalline structure whose X-ray powder diffraction pattern
exhibits the characteristic lines of FIG. 1.
[0046] The X-ray powder diffraction patterns were determined by
standard techniques. The radiation was the K-alpha/doublet of
copper.
[0047] Minor variations in the diffraction pattern can result from
variations in the silica-to-alumina or silica-to-boron mole ratio
of the particular sample due to changes in lattice constants. In
addition, sufficiently small crystals will affect the shape and
intensity of peaks, leading to significant peak broadening.
[0048] Representative peaks from the X-ray diffraction pattern of
calcined SSZ-54 are shown in FIG. 1. Calcination can also result in
changes in the intensities of the peaks as compared to patterns of
the "as-made" material, as well as minor shifts in the diffraction
pattern. The zeolite produced by exchanging the metal or other
cations present in the zeolite with various other cations (such as
H.sup.+ or NH.sub.4.sup.+) yields essentially the same diffraction
pattern, although again, there may be minor shifts in the
interplanar spacing and variations in the relative intensities of
the peaks. Notwithstanding these minor perturbations, the basic
crystal lattice remains unchanged by these treatments.
[0049] Crystalline SSZ-54 can be used as-synthesized, but
preferably will be thermally treated (calcined). Usually, it is
desirable to remove the alkali metal cation by ion exchange and
replace it with hydrogen, ammonium, or any desired metal ion. The
zeolite can be leached with chelating agents, e.g., EDTA or dilute
acid solutions, to increase the silica to alumina mole ratio. The
zeolite can also be steamed; steaming helps stabilize the
crystalline lattice to attack from acids.
[0050] The zeolite can be used in intimate combination with
hydrogenating components, such as tungsten, vanadium, molybdenum,
rhenium, nickel, cobalt, chromium, manganese or a noble metal, such
as palladium or platinum, for those applications in which a
hydrogenation-dehydrogenation function is desired.
[0051] Metals may also be introduced into the zeolite by replacing
some of the cations in the zeolite with metal cations via standard
ion exchange techniques (see, for example, U.S. Pat. No. 3,140,249
issued Jul. 7, 1964 to Plank et al.; U.S. Pat. No. 3,140,251 issued
Jul. 7, 1964 to Plank et al.; and U.S. Pat. No. 3,140,253 issued
Jul. 7, 1964 to Plank et al.). Typical replacing cations can
include metal cations, e.g., rare earth, Group IA, Group IIA and
Group VIII metals, as well as their mixtures. Of the replacing
metallic cations, cations of metals such as rare earth, Mn, Ca, Mg,
Zn, Cd, Pt, Pd, Ni, Co, Ti, Al, Sn and Fe are particularly
preferred.
[0052] The hydrogen, ammonium and metal components can be
ion-exchanged into the SSZ-54. The zeolite can also be impregnated
with the metals, or the metals can be physically and intimately
admixed with the zeolite using standard methods known to the
art.
[0053] Typical ion-exchange techniques involve contacting the
zeolite with a solution containing a salt of the desired replacing
cation or cations. Although a wide variety of salts can be
employed, chlorides and other halides, acetates, nitrates and
sulfates are particularly preferred. The zeolite is usually
calcined prior to the ion-exchange procedure to remove the organic
matter in the channels and on the surface, since this results in a
more effective ion exchange. Representative ion exchange techniques
are disclosed in a wide variety of patents including U.S. Pat. No.
3,140,249 issued Jul. 7, 1964 to Plank et al.; U.S. Pat. No.
3,140,251 issued Jul. 7, 1964 to Plank et al. and U.S. Pat. No.
3,140,253 issued on Jul. 7, 1964 to Plank et al.
[0054] Following contact with the salt solution of the desired
replacing cation, the zeolite is typically washed with water and
dried at temperatures ranging from 65.degree. C. to about
200.degree. C. After washing, the zeolite can be calcined in air or
inert gas at temperatures ranging from about 200.degree. C. to
about 800.degree. C. for periods of time ranging from 1 to 48
hours, or more, to produce a catalytically active product
especially useful in hydrocarbon conversion processes.
[0055] Regardless of the cations present in the synthesized form of
SSZ-54, the special arrangement of the atoms which form the basic
crystal lattice of the zeolite remains essentially unchanged.
[0056] SSZ-54 can be formed into a wide variety of physical shapes.
Generally speaking, the zeolite can be in the form of a powder, a
granule or a molded product, such as extrudate having a particle
size sufficient to pass through a 2-mesh (Tyler) screen and be
retained on a 400-mesh (Tyler) screen. In cases where the catalyst
is molded, such as by extrusion with an organic binder, the zeolite
can be extruded before drying, or dried or partially dried and then
extruded.
[0057] SSZ-54 can be composited with other materials resistant to
the temperatures and other conditions employed in organic
conversion processes. Such matrix materials include active and
inactive materials and synthetic or naturally occurring zeolites as
well as inorganic materials such as clays, silica and metal oxides.
Examples of such materials and the manner in which they can be used
are disclosed in U.S. Pat. No. 4,910,006, issued May 20, 1990 to
Zones et al. and U.S. Pat. No. 5,316,753, issued May 31, 1994 to
Nakagawa, both of which are incorporated by reference herein in
their entirety.
[0058] SSZ-54 can be employed in catalysts useful for catalyzing
hydrocarbon conversion reactions such as hydrocracking, dewaxing,
isomerization and the like.
EXAMPLES
[0059] The following examples demonstrate but do not limit the
present invention.
Example 1
Preparation of SSZ-54
[0060] Into the Teflon cup of a Parr 23 ml reactor is placed 2 ml
of a 1N KOH solution, 4 grams of water and 0.30 grams of
N-isopropyl ethylenediamine. The resulting mixture is mixed by
hand. 1.27 Grams of Ludox AS-30 colloidal silica (30% SiO.sub.2) is
added and then 0.90 gram of Nalco 1056 colloidal silica particles
coated with Al.sub.2O.sub.3 is added last. The resulting reaction
mixture has a silica/alumina mole ratio ("SAR") of 30. The reactor
is sealed and heated at 170.degree. C. with 43 RPM tumbling for
four weeks. Analysis by XRD shows the product to be SSZ-54.
Example 2
Preparation of SSZ-54
[0061] A reaction is carried out as described in Example 1 except
that the SAR is adjusted to 40 by using 1.47 grams Ludox AS-30
colloidal silica and 0.62 gram Nalco 1056 colloidal silica. A
product is produced after two weeks and identified by XRD as
SSZ-54.
Example 3
Preparation of SSZ-54
[0062] A reaction is carried out as described in Example 1 except
that the SAR is adjusted to 50 by using 1.57 grams Ludox AS-30
colloidal silica and 0.52 gram Nalco 1056 colloidal silica. A
product is produced after three weeks and identified by XRD as
mostly SSZ-54 with a minor amount of cristobalite.
Example 4
Preparation of SSZ-54
[0063] 0.088 Gram of Reheis F-200 dried aluminum hydroxide gel
(50-53 wt. % Al.sub.2O.sub.3) is dissolved in 3 ml of a 1N KOH
solution, 8.4 grams water and 0.40 gram N-isopropyl
ethylenediamine. 0.90 Gram of Cabosil M5 fumed silica is blended
into the resulting reaction mixture and the reactor is closed,
sealed and heated at 170.degree. C. with 45 RPM tumbling. At nine
days of run time, the reaction mixture is cooled and the product is
collected and washed. XRD analysis shows the product to be SSZ-54.
The product had a SAR of 36.
Example 5
Preparation of SSZ-54
[0064] In the Teflon cup of a Parr 23 ml reactor, 3 grams of 1 N
KOH solution, 5 grams of water and 1.90 grams of Ludox AS-30
colloidal silica are mixed. Then 0.07 gram (0.5 millimole) of
1-N-isopropyldiethylenetriam- ine is added to the cup. Next, 1.30
grams of Nalco 1056 colloidal silica (26 wt. % silica coated with 4
wt. % alumina) is added with spatula stirring. 0.22 Grams of
isobutylamine is added and the reactor is closed and heated at
170.degree. C. with 43 rpm tumbling. After six days, a sample is
taken for scanning electron microscopy. A crystalline material is
recovered and found by XRD to be SSZ-54.
Examples 6-9
[0065] Reactions are run in a manner similar to that described in
Example 1 using the reagents shown in the table below. Amounts of
reagents are in grams; the seeds are previously made SSZ-54. The
product of each reaction is also shown in the table.
6 Rxn. Ex. 1N Reheis mix. No. KOH F-2000 Q.sup.(a) Nyacol.sup.(b)
H.sub.2O Seeds SAR Product 6 3.0 0.10 0.40 2.25 5.0 0.05 30 SSZ-54
7 3.0 0.08 0.40 2.25 5.0 0.05 37 SSZ-54 8 3.0 0.06 0.40 2.25 5.0
0.05 50 SSZ-54 9 3.0 0.02 0.40 2.25 5.0 0.05 150 Cristob alite +
Minor SSZ-54 .sup.(a)N-isopropyl ethylenediamine .sup.(b)colloidal
silica (40% SiO.sub.2)
Example 10
Calcination of SSZ-54
[0066] The material from Example 1 is calcined in the following
manner. A thin bed of material is heated in a muffle furnace from
room temperature to 120.degree. C. at a rate of 1.degree. C. per
minute and held at 120.degree. C. for three hours. The temperature
is then ramped up to 540.degree. C. at the same rate and held at
this temperature for 5 hours, after which it is increased to
594.degree. C. and held there for another 5 hours. A 50/50 mixture
of air and nitrogen is passed over the zeolite at a rate of 20
standard cubic feet per minute during heating.
Example 11
NH.sub.4 Exchange
[0067] Ion exchange of calcined SSZ-54 material (prepared in
Example 10) is performed using NH.sub.4NO.sub.3 to convert the
zeolite from its Na.sup.+ form to the NH.sub.4.sup.+ form, and,
ultimately, the H.sup.+ form. Typically, the same mass of
NH.sub.4NO.sub.3 as zeolite is slurried in water at a ratio of
25-50:1 water to zeolite. The exchange solution is heated at
95.degree. C. for 2 hours and then filtered. This procedure can be
repeated up to three times. Following the final exchange, the
zeolite is washed several times with water and dried. This
NH.sub.4.sup.+ form of SSZ-54 can then be converted to the H.sup.+
form by calcination (as described in Example 9) to 540.degree.
C.
Example 12
Constraint Index Determination
[0068] The hydrogen form of the zeolite of Example 11 is pelletized
at 2-3 KPSI, crushed and meshed to 20-40, and then >0.50 gram is
calcined at about 540.degree. C. in air for four hours and cooled
in a desiccator. 0.50 Gram is packed into a 3/8 inch stainless
steel tube with alundum on both sides of the zeolite bed. A
Lindburg furnace is used to heat the reactor tube. Helium is
introduced into the reactor tube at 10 cc/min. and at atmospheric
pressure. The reactor is heated to about 800.degree. F., and a
50/50 (w/w) feed of n-hexane and 3-methylpentane is introduced into
the reactor at a rate of 8 .mu.l/min. Feed delivery is made via a
Brownlee pump. Direct sampling into a gas chromatograph begins
after 10 minutes of feed introduction. The Constraint Index value
is calculated from the gas chromatographic data using methods known
in the art, and is found to be 21. At 800.degree. F and 40 minutes
on-stream, feed conversion was 40%.
* * * * *