Molecular sieve abstract
The present invention relates to new crystalline molecular sieve
SSZ-63 prepared using N-cyclodecyl-N-methyl-pyrrolidinium cation
as a structure-directing agent, methods for synthesizing SSZ-63
and processes employing SSZ-63 in a catalyst.
Molecular sieve claims
What is claimed is:
1. A process for converting hydrocarbons comprising contacting
a hydrocarbonaceous feed at hydrocarbon converting conditions with
a catalyst comprising a zeolite having a mole ratio greater than
about 15 of an oxide of a first tetravalent clement 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 lines
of Table II.
2. The process of claim 1 wherein the zeolite is predominantly
in the hydrogen form.
3. The process of claim 1 wherein the zeolite is substantially
free of acidity.
4. The process of claim 1 wherein the process is a hydrocracking
process comprising contacting the catalyst with a hydrocarbon feedstock
under hydrocracking conditions.
5. The process of claim 4 wherein the zeolite is predominantly
in the hydrogen form.
6. The process of claim 1 wherein the process is a dewaxing process
comprising contacting the catalyst with a hydrocarbon feedstock
under dewaxing conditions.
7. The process of claim 6 wherein the zeolite is predominantly
in the hydrogen form.
8. The process of claim 1 wherein the process is a process for
improving the viscosity index of a dewaxed product of waxy hydrocarbon
feeds comprising contacting the catalyst with a waxy hydrocarbon
feed under isomerization dewaxing conditions.
9. The process of claim 8 wherein the zeolite is predominantly
in the hydrogen form.
10. The process of claim 1 wherein the process is a process for
producing a C.sub.20+ lube oil from a C.sub.20+ olefin feed comprising
isomerizing said olefin feed under isomerization conditions over
the catalyst.
11. The process of claim 10 wherein the zeolite is predominantly
in the hydrogen form.
12. The process of claim 10 wherein the catalyst further comprises
at least one Group VIII metal.
13. The process of claim 1 wherein the process is a process for
catalytically dewaxing a hydrocarbon oil feedstock boiling above
about 350.degree. F. and containing straight chain and slightly
branched chain hydrocarbons comprising contacting said hydrocarbon
oil feedstock in the presence of added hydrogen gas at a hydrogen
pressure of about 15-3000 psi under dewaxing conditions with the
catalyst.
14. The process of claim 13 wherein the zeolite is predominantly
in the hydrogen form.
15. The process of claim 13 wherein the catalyst further comprises
at least one Group VIII metal.
16. The process of claim 13 wherein said catalyst comprises a layered
catalyst comprising a first layer comprising the zeolite and at
least one Group VIII metal, and a second layer comprising an aluminosilicate
zeolite which is more shape selective than the zeolite of said first
layer.
17. The process of claim 1 wherein the process is a process for
preparing a lubricating oil which comprises: hydrocracking in a
hydrocracking zone a hydrocarbonaceous feedstock to obtain an effluent
comprising a hydrocracked oil; and catalytically dewaxing said effluent
comprising hydrocracked oil at a temperature of at least about 400.degree.
F. and at a pressure of from about 15 psig to about 3000 psig in
the presence of added hydrogen gas with the catalyst.
18. The process of claim 17 wherein the zeolite is predominantly
in the hydrogen form.
19. The process of claim 17 wherein the catalyst further comprises
at least one Group VIII metal.
20. The process of claim 1 wherein the process is a process for
isomerization dewaxing a raffinate comprising contacting said raffinate
in the presence of added hydrogen under isomerization dewaxing conditions
with the catalyst.
21. The process of claim 20 wherein the zeolite is predominantly
in the hydrogen form.
22. The process of claim 20 wherein the catalyst further comprises
at least one Group VIII metal.
23. The process of claim 20 wherein the raffinate is bright stock.
24. The process of claim 1 wherein the process is a process for
increasing the octane of a hydrocarbon feedstock to produce a product
having an increased aromatics content comprising contacting a hydrocarbonaceous
feedstock which comprises normal and slightly branched hydrocarbons
having a boiling range above about 40.degree. C. and less than about
200.degree. C. under aromatic conversion conditions with the catalyst.
25. The process of claim 24 wherein the zeolite is substantially
free of acid.
26. The process of claim 24 wherein the zeolite contains a Group
VIII metal component.
27. The process of claim 1 wherein the process is a catalytic cracking
process comprising contacting a hydrocarbon feedstock in a reaction
zone under catalytic cracking conditions in the absence of added
hydrogen with the catalyst.
28. The process of claim 27 wherein the zeolite is predominantly
in the hydrogen form.
29. The process of claim 27 wherein the catalyst additionally comprises
a large pore crystalline cracking component.
30. The process of claim 1 wherein the process is an isomerization
process for isomerizing C.sub.4 to C.sub.7 hydrocarbons, comprising
contacting a feed having normal and slightly branched C.sub.4 to
C.sub.7 hydrocarbons under isomerizing conditions with the catalyst.
31. The process of claim 30 wherein the zeolite is predominantly
in the hydrogen form.
32. The process of claim 30 wherein the zeolite has been impregnated
with at least one Group VIII metal.
33. The process of claim 30 wherein the catalyst has been calcined
in a steam/air mixture at an elevated temperature after impregnation
of the Group VIII metal.
34. The process of claim 32 wherein the Group VIII metal is platinum.
35. The process of claim 1 wherein the process is a process for
alkylating an aromatic hydrocarbon which comprises contacting under
alkylation conditions at least a molar excess of an aromatic hydrocarbon
with a C.sub.2 to C.sub.20 olefin under at least partial liquid
phase conditions and in the presence of the catalyst.
36. The process of claim 35 wherein the zeolite is predominantly
in the hydrogen form.
37. The process of claim 35 wherein the olefin is a C.sub.2 to
C.sub.4 olefin.
38. The process of claim 37 wherein the aromatic hydrocarbon and
olefin are present in a molar ratio of about 4:1 to about 20:1
respectively.
39. The process of claim 37 wherein the aromatic hydrocarbon is
selected from the group consisting of benzene, toluene, ethylbenzene,
xylene, naphthalene, naphthalene derivatives, dimethylnaphthalene
or mixtures thereof.
40. The process of claim 1 wherein the process is a process for
transalkylating an aromatic hydrocarbon which comprises contacting
under transalkylating conditions an aromatic hydrocarbon with a
polyalkyl aromatic hydrocarbon under at least partial liquid phase
conditions and in the presence of the catalyst.
41. The process of claim 40 wherein the zeolite is predominantly
in the hydrogen form.
42. The process of claim 40 wherein the aromatic hydrocarbon and
the polyalkyl aromatic hydrocarbon are present in a molar ratio
of from about 1:1 to about 25:1 respectively.
43. The process of claim 40 wherein the aromatic hydrocarbon is
selected from the group consisting of benzene, toluene, ethylbenzene,
xylene, or mixtures thereof.
44. The process of claim 40 wherein the polyalkyl aromatic hydrocarbon
is a dialkylbenzene.
45. The process of claim 1 wherein the process is a process to
convert paraffins to aromatics which comprises contacting paraffins
under conditions which cause paraffins to convert to aromatics with
a catalyst comprising the zeolite and gallium, zinc, or a compound
of gallium or zinc.
46. The process of claim 1 wherein the process is a process for
isomerizing olefins comprising contacting said olefin under conditions
which cause isomerization of the olefin with the catalyst.
47. The process of claim 1 wherein the process is a process for
isomerizing an isomerization feed comprising an aromatic C.sub.8
stream of xylene isomers or mixtures of xylene isomers and ethylbenzene,
wherein a more nearly equilibrium ratio of ortho-, meta and para-xylenes
is obtained, said process comprising contacting said feed under
isomerization conditions with the catalyst.
48. The process of claim 1 wherein the process is a process for
oligomerizing olefins comprising contacting an olefin feed under
oligomerization conditions with the catalyst.
49. A process for converting oxygenated hydrocarbons comprising
contacting said oxygenated hydrocarbon under conditions to produce
liquid products with a catalyst comprising a zeolite having a mole
ratio greater than about 15 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
lines of Table II.
50. The process of claim 49 wherein the oxygenated hydrocarbon
is a lower alcohol.
51. The process of claim 50 wherein the lower alcohol is methanol.
52. The process of claim 1 wherein the process is a process for
the production of higher molecular weight hydrocarbons from lower
molecular weight hydrocarbons comprising the steps of: (a) introducing
into a reaction zone a lower molecular weight hydrocarbon-containing
gas and contacting said gas in said zone under C.sub.2+ hydrocarbon
synthesis conditions with the catalyst and a metal or metal compound
capable of converting the lower molecular weight hydrocarbon to
a higher molecular weight hydrocarbon; and (b) withdrawing from
said reaction zone a higher molecular weight hydrocarbon-containing
stream.
53. The process of claim 52 wherein the metal or metal compound
comprises a lanthanide or actinide metal or metal compound.
54. The process of claim 52 wherein the lower molecular weight
hydrocarbon is methane.
Molecular sieve description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to new crystalline molecular sieve
SSZ-63 a method for preparing SSZ-63 using N-cyclodecyl-N-methyl-pyrrolidinium
cation as a structure directing agent and the use of SSZ-63 in catalysts
for, e.g., hydrocarbon conversion reactions.
2. State of the Art
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.
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
The present invention is directed to a family of crystalline molecular
sieves with unique properties, referred to herein as "molecular
sieve SSZ-63" or simply "SSZ-63". Preferably, SSZ-63
is obtained in its silicate, aluminosilicate, titanosilicate, germanosilicate,
vanadosilicate or borosilicate form. The term "silicate"
refers to a molecular sieve having a high mole ratio of silicon
oxide relative to aluminum oxide, preferably a mole ratio greater
than 100 including molecular sieves comprised entirely of silicon
oxide. As used herein, the term "aluminosilicate" refers
to a molecular sieve containing both alumina and silica and the
term "borosilicate" refers to a molecular sieve containing
oxides of both boron and silicon.
In accordance with the present invention there is provided a process
for converting hydrocarbons comprising contacting a hydrocarbonaceous
feed at hydrocarbon converting conditions with a catalyst comprising
the zeolite of this invention. The zeolite may be predominantly
in the hydrogen form. It may also be substantially free of acidity.
Further provided by the present invention is a hydrocracking process
comprising contacting a hydrocarbon feedstock under hydrocracking
conditions with a catalyst comprising the zeolite of this invention,
preferably predominantly in the hydrogen form.
This invention also includes a dewaxing process comprising contacting
a hydrocarbon feedstock under dewaxing conditions with a catalyst
comprising the zeolite of this invention, preferably predominantly
in the hydrogen form.
The present invention also includes a process for improving the
viscosity index of a dewaxed product of waxy hydrocarbon feeds comprising
contacting the waxy hydrocarbon feed under isomerization dewaxing
conditions with a catalyst comprising the zeolite of this invention,
preferably predominantly in the hydrogen form.
The present invention further includes a process for producing
a C.sub.20+ lube oil from a C.sub.20+ olefin feed comprising isomerizing
said olefin feed under isomerization conditions over a catalyst
comprising the zeolite of this invention. The zeolite may be predominantly
in the hydrogen form. The catalyst may contain at least one Group
VIII metal.
In accordance with this invention, there is also provided a process
for catalytically dewaxing a hydrocarbon oil feedstock boiling above
about 350.degree. F. and containing straight chain and slightly
branched chain hydrocarbons comprising contacting said hydrocarbon
oil feedstock in the presence of added hydrogen gas at a hydrogen
pressure of about 15-3000 psi with a catalyst comprising the zeolite
of this invention, preferably predominantly in the hydrogen form.
The catalyst may contain at least one Group VIII metal. The catalyst
may be a layered catalyst comprising a first layer comprising the
zeolite of this invention, and a second layer comprising an aluminosilicate
zeolite which is more shape selective than the zeolite of said first
layer. The first layer may contain at least one Group VIII metal.
Also included in the present invention is a process for preparing
a lubricating oil which comprises hydrocracking in a hydrocracking
zone a hydrocarbonaceous feedstock to obtain an effluent comprising
a hydrocracked oil, and catalytically dewaxing said effluent comprising
hydrocracked oil at a temperature of at least about 400.degree.
F. and at a pressure of from about 15 psig to about 3000 psig in
the presence of added hydrogen gas with a catalyst comprising the
zeolite of this invention. The zeolite may be predominantly in the
hydrogen form. The catalyst may contain at least one Group VIII
metal.
Further included in this invention is a process for isomerization
dewaxing a raffinate comprising contacting said raffinate in the
presence of added hydrogen with a catalyst comprising the zeolite
of this invention. The raffinate may be bright stock, and the zeolite
may be predominantly in the hydrogen form. The catalyst may contain
at least one Group VIII metal.
Also included in this invention is a process for increasing the
octane of a hydrocarbon feedstock to produce a product having an
increased aromatics content comprising contacting a hydrocarbonaceous
feedstock which comprises normal and slightly branched hydrocarbons
having a boiling range above about 40.degree. C. and less than about
200.degree. C., under aromatic conversion conditions with a catalyst
comprising the zeolite of this invention made substantially free
of acidity by neutralizing said zeolite with a basic metal. Also
provided in this invention is such a process wherein the zeolite
contains a Group VIII metal component.
Also provided by the present invention is a catalytic cracking
process comprising contacting a hydrocarbon feedstock in a reaction
zone under catalytic cracking conditions in the absence of added
hydrogen with a catalyst comprising the zeolite of this invention,
preferably predominantly in the hydrogen form. Also included in
this invention is such a catalytic cracking process wherein the
catalyst additionally comprises a large pore crystalline cracking
component.
This invention further provides an isomerization process for isomerizing
C.sub.4 to C.sub.7 hydrocarbons, comprising contacting a feed having
normal and slightly branched C.sub.4 to C.sub.7 hydrocarbons under
isomerizing conditions with a catalyst comprising the zeolite of
this invention, preferably predominantly in the hydrogen form. The
zeolite may be impregnated with at least one Group VIII metal, preferably
platinum. The catalyst may be calcined in a steam/air mixture at
an elevated temperature after impregnation of the Group VIII metal.
Also provided by the present invention is a process for alkylating
an aromatic hydrocarbon which comprises contacting under alkylation
conditions at least a molar excess of an aromatic hydrocarbon with
a C.sub.2 to C.sub.20 olefin under at least partial liquid phase
conditions and in the presence of a catalyst comprising the zeolite
of this invention, preferably predominantly in the hydrogen form.
The olefin may be a C.sub.2 to C.sub.4 olefin, and the aromatic
hydrocarbon and olefin may be present in a molar ratio of about
4:1 to about 20:1 respectively. The aromatic hydrocarbon may be
selected from the group consisting of benzene, toluene, ethylbenzene,
xylene, naphthalene, naphthalene derivatives, dimethylnaphthalene
or mixtures thereof.
Further provided in accordance with this invention is a process
for transalkylating an aromatic hydrocarbon which comprises contacting
under transalkylating conditions an aromatic hydrocarbon with a
polyalkyl aromatic hydrocarbon under at least partial liquid phase
conditions and in the presence of a catalyst comprising the zeolite
of this invention, preferably predominantly in the hydrogen form.
The aromatic hydrocarbon and the polyalkyl aromatic hydrocarbon
may be present in a molar ratio of from about 1:1 to about 25:1
respectively.
The aromatic hydrocarbon may be selected from the group consisting
of benzene, toluene, ethylbenzene, xylene, or mixtures thereof,
and the polyalkyl aromatic hydrocarbon may be a dialkylbenzene.
Further provided by this invention is a process to convert paraffins
to aromatics which comprises contacting paraffins under conditions
which cause paraffins to convert to aromatics with a catalyst comprising
the zeolite of this invention, said catalyst comprising gallium,
zinc, or a compound of gallium or zinc.
In accordance with this invention there is also provided a process
for isomerizing olefins comprising contacting said olefin under
conditions which cause isomerization of the olefin with a catalyst
comprising the zeolite of this invention.
Further provided in accordance with this invention is a process
for isomerizing an isomerization feed comprising an aromatic C.sub.8
stream of xylene isomers or mixtures of xylene isomers and ethylbenzene,
wherein a more nearly equilibrium ratio of ortho-, meta- and para-xylenes
is obtained, said process comprising contacting said feed under
isomerization conditions with a catalyst comprising the zeolite
of this invention.
The present invention further provides a process for oligomerizing
olefins comprising contacting an olefin feed under oligomerization
conditions with a catalyst comprising the zeolite of this invention.
This invention also provides a process for converting oxygenated
hydrocarbons comprising contacting said oxygenated hydrocarbon with
a catalyst comprising the zeolite of this invention under conditions
to produce liquid products. The oxygenated hydrocarbon may be a
lower alcohol.
Further provided in accordance with the present invention is a
process for the production of higher molecular weight hydrocarbons
from lower molecular weight hydrocarbons comprising the steps of:
(a) introducing into a reaction zone a lower molecular weight hydrocarbon-containing
gas and contacting said gas in said zone under C.sub.2+ hydrocarbon
synthesis conditions with the catalyst and a metal or metal compound
capable of converting the lower molecular weight hydrocarbon to
a higher molecular weight hydrocarbon; and (b) withdrawing from
said reaction zone a higher molecular weight hydrocarbon-containing
stream.
BRIEF DESCRIPTION OF THE DRAWING
The drawing is a powder X-ray diffraction pattern of calcined SSZ-63.
DETAILED DESCRIPTION OF THE INVENTION
The present invention comprises a family of crystalline, large
pore molecular sieves designated herein "molecular sieve SSZ-63"
or simply "SSZ-63". As used herein, the term "large
pore" means having an average pore size diameter greater than
about 6.0 Angstroms, preferably from about 6.5 Angstroms to about
7.5 Angstroms.
While not wishing to be bound by any theory, it is believed that
the crystal structure of SSZ-63 consists of two polymorphs of zeolite
beta. Typical zeolite beta (BEA*) has a crystal structure consisting
of about a 50/50 combination of two polymorphs, polymorph A and
polymorph B. It is believed that the crystal structure of SSZ-63
consists of about 60-70% of a beta polymorph referred to herein
as beta-C (Higgins) with the remainder being beta polymorph B. Beta
polymorph C (Higgins) is different from beta polymorph C. The structure
of polymorph C (Higgins) has been postulated in the literature,
but it is believed that polymorph C (Higgins) has heretofore not
been made. A discussion of polymorph C (Higgins) can be found in
Higgins et al, "The framework Topology of Zeolite Beta",
Zeolites, 1988 vol. 8 pp. 446-452 with a correction at Higgins
et al., "The Framework Topology of Zeolite Beta--A Correction",
Zeolites, 1989 vol. 9 p. 358.
In preparing SSZ-63 N-cyclodecyl-N-methyl-pyrrolidinium cation
is used as a structure directing agent ("SDA"), also known
as a crystallization template. In general, SSZ-63 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, tetravalent element oxides and
pentavalent elements with the N-cyclodecyl-N-methyl-pyrrolidinium
cation SDA.
SSZ-63 is prepared from a reaction mixture having the composition
shown in Table A below.
TABLE A Reaction Mixture Typical Preferred YO.sub.2 /W.sub.a O.sub.b
>15 30-70 OH-/YO.sub.2 0.10-0.50 0.20-0.30 Q/YO.sub.2 0.05-0.50
0.10-0.20 M.sub.2/n /YO.sub.2 0.02-0.40 0.10-0.25 H.sub.2 O/YO.sub.2
30-80 35-45
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).
In practice, SSZ-63 is prepared by a process comprising:
(a) preparing an aqueous solution containing sources of at least
one oxide capable of forming a crystalline molecular sieve and a
N-cyclodecyl-N-methyl-pyrrolidinium cation having an anionic counterion
which is not detrimental to the formation of SSZ-63;
(b) maintaining the aqueous solution under conditions sufficient
to form crystals of SSZ-63; and
(c) recovering the crystals of SSZ-63.
Accordingly, SSZ-63 may comprise the crystalline material and the
SDA 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
trivalent element(s), pentavalent element(s), second tetravalent
element(s) different from the first tetravalent 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 trivalent element, pentavalent element and second tetravalent
element (which is different from the first tetravalent 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.
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.
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. 5225179 issued Jul.
6 1993 to Nakagawa entitled "Method of Making Molecular Sieves",
the disclosure of which is incorporated herein by reference.
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 SDA may be used to provide hydroxide
ion. Thus, it may be beneficial to ion exchange, for example, the
halide to 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.
The reaction mixture is maintained at an elevated temperature until
the crystals of the SSZ-63 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.
Preferably, the molecular sieve is prepared using mild stirring
or agitation.
During the hydrothermal crystallization step, the SSZ-63 crystals
can be allowed to nucleate spontaneously from the reaction mixture.
The use of SSZ-63 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-63 over any undesired phases. When used as seeds, SSZ-63 crystals
arc added in an amount between 0.1 and 10% of the weight of silica
used in the reaction mixture.
Once the molecular sieve 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-63 crystals. The drying
step can be performed at atmospheric pressure or under vacuum.
SSZ-63 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 15; and has, after calcination, the X-ray diffraction
lines of Table II below. SSZ-63 further has a composition, as synthesized
(i.e., prior to removal of the SDA from the SSZ-63) and in the anhydrous
state, in terms of mole ratios, shown in Table B below.
TABLE B As-Synthesized SSZ-63 YO.sub.2 /W.sub.c O.sub.d >15
M.sub.2/n /YO.sub.2 0.01-0.03 Q/YO.sub.2 0.02-0.05
where Y, W, c, d, M, n and Q are as defined above.
SSZ-63 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-63
can be synthesized directly using essentially aluminum-free silicon
sources as the main tetrahedral metal oxide component, if boron
is also present. The boron can then be removed, if desired, by treating
the borosilicate SSZ-63 with acetic acid at elevated temperature
(as described in Jones et al., Chem. Mater., 2001 13 1041-1050)
to produce an all-silica version of SSZ-63. SSZ-63 can also be prepared
directly as a borosilicate. If desired, the boron can be removed
as described above and replaced With metal atoms by techniques known
in the art to make, e.g., an aluminosilicate version of SSZ-63.
SSZ-63 can also be prepared directly as an aluminosilicate.
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. 4559315 issued
on Dec. 17 1985 to Chang et al.
It is believed that SSZ-63 is comprised of a new framework structure
or topology which is characterized by its X-ray diffraction pattern.
SSZ-63 as-synthesized, has a crystalline structure whose X-ray
powder diffraction pattern exhibit the characteristic lines shown
in Table I and is thereby distinguished from other molecular sieves.
TABLE I As-Synthesized SSZ-63 2 Theta.sup.(a) d-spacing (Angstroms)
Relative Intensity (%) 7.17 12.32 W 7.46 11.84 W 7.86 11.24 W 8.32
10.62 W 21.42 4.15 M 22.46 3.96 VS 22.85 3.89 W 25.38 3.51 W 27.08
3.29 W 29.62 3.01 W .sup.(a).+-.0.2 .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.
Table IA below shows the X-ray powder diffraction lines for as-synthesized
SSZ-63 including actual relative intensities.
TABLE IA 2 Theta.sup.(a) d-spacing (Angstroms) Relative Intensity
(%) 7.17 12.32 5.1 7.46 11.84 13.5 7.86 11.24 10.2 8.32 10.62 4.7
13.38 6.61 1.7 17.20 5.15 1.4 18.21 4.87 2.0 19.29 4.60 1.5 21.42
4.15 15.7 22.46 3.96 100.0 22.85 3.89 6.9 25.38 3.51 6.7 26.02 3.42
1.8 27.08 3.29 12.3 28.80 3.10 3.2 29.62 3.01 8.5 30.50 2.93 2.9
32.88 2.72 1.4 33.48 2.67 5.7 34.76 2.58 1.8 36.29 2.47 1.6 37.46
2.40 1.3 .sup.(a).+-.0.2
After calcination, the SSZ-63 molecular sieves have a crystalline
structure whose X-ray powder diffraction pattern include the characteristic
lines shown in Table II:
TABLE II Calcined SSZ-63 2 Theta.sup.(a) d-spacing (Angstroms)
Relative Intensity (%) 7.19 12.29 M 7.42 11.91 VS 7.82 11.30 VS
8.30 10.64 M 13.40 6.60 M 21.46 4.14 W 22.50 3.95 VS 22.81 3.90
W 27.14 3.28 M 29.70 3.06 W .sup.(a).+-.0.2
Table IIA below shows the X-ray powder diffraction lines for calcined
SSZ-63 including actual relative intensities.
TABLE IIA 2 Theta.sup.(a) d-spacing (Angstroms) Relative Intensity
(%) 7.19 12.29 27.7 7.42 11.91 68.5 7.82 11.29 67.0 8.30 10.64 40.1
10.46 8.45 3.1 11.31 7.82 6.7 13.40 6.60 25.1 14.38 6.16 5.3 14.60
6.06 6.5 21.46 4.14 11.2 22.50 3.95 100.0 22.81 3.90 13.0 25.42
3.50 9.2 27.14 3.28 19.6 28.80 3.10 8.2 29.70 3.01 11.0 30.48 2.93
3.3 33.56 2.67 3.9 34.86 2.57 3.3 36.29 2.47 3.2 37.64 2.39 2.8
.sup.(a).+-.0.2
The X-ray powder diffraction patterns were determined by standard
techniques. The radiation was the K-alpha/doublet of copper. The
peak heights and the positions, as a function of 2.theta. where
.theta. is the Bragg angle, were read from the relative intensities
of the peaks, and d, the interplanar spacing in Angstroms corresponding
to the recorded lines, can be calculated.
The variation in the scattering angle (two theta) measurements,
due to instrument error and to differences between individual samples,
is estimated at .+-.0.20 degrees.
The X-ray diffraction pattern of Table I is representative of "as-synthesized"
or "as-made" SSZ-63 molecular sieves. 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.
Representative peaks from the X-ray diffraction pattern of calcined
SSZ-63 are shown in Table II. 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
molecular sieve produced by exchanging the metal or other cations
present in the molecular sieve 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.
Crystalline SSZ-63 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 molecular sieve can be leached
with chelating agents, e.g., EDTA or dilute acid solutions, to increase
the silica to alumina mole ratio. The molecular sieve can also be
steamed; steaming helps stabilize the crystalline lattice to attack
from acids.
The molecular sieve 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.
Metals may also be introduced into the molecular sieve by replacing
some of the cations in the molecular sieve with metal cations via
standard ion exchange techniques (see, for example, U.S. Pat. No.
3140249 issued Jul. 7 1964 to Plank et al.; U.S. Pat. No. 3140251
issued Jul. 7 1964 to Plank et al.; and U.S. Pat. No. 3140253
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.
The hydrogen, ammonium, and metal components can be ion-exchanged
into the SSZ-63. The SSZ-63 can also be impregnated with the metals,
or the metals can be physically and intimately admixed with the
SSZ-63 using standard methods known to the art.
Typical ion-exchange techniques involve contacting the synthetic
molecular sieve 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 molecular sieve is usually
calcined prior to the ion-exchange procedure to remove the organic
matter present 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.
3140249 issued on Jul. 7 1964 to Plank et al.; U.S. Pat. No.
3140251 issued on Jul. 7 1964 to Plank et al.; and U.S. Pat.
No. 3140253 issued on Jul. 7 1964 to Plank et al.
Following contact with the salt solution of the desired replacing
cation, the molecular sieve is typically washed with water and dried
at temperatures ranging from 65.degree. C. to about 200.degree.
C. After washing, the molecular sieve 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.
Regardless of the cations present in the synthesized form of SSZ-63
the spatial arrangement of the atoms which form the basic crystal
lattice of the molecular sieve remains essentially unchanged.
SSZ-63 can be formed into a wide variety of physical shapes. Generally
speaking, the molecular sieve 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 SSZ-63 can be extruded
before drying, or, dried or partially dried and then extruded.
SSZ-63 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. 4910006 issued May 20 1990 to Zones et al.,
and U.S. Pat. No. 5316753 issued May 31 1994 to Nakagawa, both
of which are incorporated by reference herein in their entirety.
SSZ-63 is useful in catalysts for a variety of hydrocarbon conversion
reactions such as hydrocracking, dewaxing, isomerization and the
like.
Hydrocarbon Conversion Processes
SSZ-63 zeolites are useful in hydrocarbon conversion reactions.
Hydrocarbon conversion reactions are chemical and catalytic processes
in which carbon containing compounds are changed to different carbon
containing compounds. Examples of hydrocarbon conversion reactions
in which SSZ-63 are expected to be useful include hydrocracking,
dewaxing, catalytic cracking and olefin and aromatics formation
reactions. The catalysts are also expected to be useful in other
petroleum refining and hydrocarbon conversion reactions such as
isomerizing n-paraffins and naphthenes, polymerizing and oligomerizing
olefinic or acetylenic compounds such as isobutylene and butene-1
reforming, isomerizing polyalkyl substituted aromatics (e.g., m-xylene),
and disproportionating aromatics (e.g., toluene) to provide mixtures
of benzene, xylenes and higher methylbenzenes and oxidation reactions.
Also included are rearrangement reactions to make various naphthalene
derivatives, and forming higher molecular weight hydrocarbons from
lower molecular weight hydrocarbons (e.g., methane upgrading). The
SSZ-63 catalysts may have high selectivity, and under hydrocarbon
conversion conditions can provide a high percentage of desired products
relative to total products.
SSZ-63 zeolites can be used in processing hydrocarbonaceous feedstocks.
Hydrocarbonaceous feedstocks contain carbon compounds and can be
from many different sources, such as virgin petroleum fractions,
recycle petroleum fractions, shale oil, liquefied coal, tar sand
oil, synthetic paraffins from NAO, recycled plastic feedstocks and,
in general, can be any carbon containing feedstock susceptible to
zeolitic catalytic reactions. Depending on the type of processing
the hydrocarbonaceous feed is to undergo, the feed can contain metal
or be free of metals, it can also have high or low nitrogen or sulfur
impurities. It can be appreciated, however, that in general processing
will be more efficient (and the catalyst more active) the lower
the metal, nitrogen, and sulfur content of the feedstock.
The conversion of hydrocarbonaceous feeds can take place in any
convenient mode, for example, in fluidized bed, moving bed, or fixed
bed reactors depending on the types of process desired. The formulation
of the catalyst particles will vary depending on the conversion
process and method of operation.
Other reactions which can be performed using the catalyst of this
invention containing a metal, e.g., a Group VIII metal such platinum,
include hydrogenation-dehydrogenation reactions, denitrogenation
and desulfurization reactions.
The following table indicates typical reaction conditions which
may be employed when using catalysts comprising SSZ-63 in the hydrocarbon
conversion reactions of this invention. Preferred conditions are
indicated in parentheses.
Process Temp., .degree. C. Pressure LHSV Hydrocracking 175-485
0.5-350 bar 0.1-30 Dewaxing 200-475 15-3000 psig 0.1-20 (250-450)
(200-3000) (0.2-10) Aromatics 400-600 atm.-10 bar 0.1-15 formation
(480-550) Cat. cracking 127-885 subatm.-.sup.1 0.5-50 (atm.-5 atm.)
Oligomerization 232-649.sup.2 0.1-50 atm..sup.23 0.2-50.sup.2 10-232.sup.4
-- 0.05-20.sup.5 (27-204).sup.4 -- (0.1-10).sup.5 Paraffins to 100-700
0-1000 psig 0.5-40.sup.5 aromatics Condensation of 260-538 0.5-1000
psig 0.5-50.sup.5 alcohols Isomerization 93-538 50-1000 psig 1-10
(204-315) (1-4) Xylene 260-593.sup.2 0.5-50 atm..sup.2 0.1-100.sup.5
isomerization (315-566).sup.2 (1-5 atm).sup.2 (0.5-50).sup.5 38-371.sup.4
1-200 atm..sup.4 0.5-50 .sup.1 Several hundred atmospheres .sup.2
Gas phase reaction .sup.3 Hydrocarbon partial pressure .sup.4 Liquid
phase reaction .sup.5 WHSV
Other reaction conditions and parameters are provided below.
Hydrocracking
Using a catalyst which comprises SSZ-63 preferably predominantly
in the hydrogen form, and a hydrogenation promoter, heavy petroleum
residual feedstocks, cyclic stocks and other hydrocrackate charge
stocks can be hydrocracked using the process conditions and catalyst
components disclosed in the aforementioned U.S. Pat. No. 4910006
and U.S. Pat. No. 5316753.
The hydrocracking catalysts contain an effective amount of at least
one hydrogenation component of the type commonly employed in hydrocracking
catalysts. The hydrogenation component is generally selected from
the group of hydrogenation catalysts consisting of one or more metals
of Group VIB and Group VIII, including the salts, complexes and
solutions containing such. The hydrogenation catalyst is preferably
selected from the group of metals, salts and complexes thereof of
the group consisting of at least one of platinum, palladium, rhodium,
iridium, ruthenium and mixtures thereof or the group consisting
of at least one of nickel, molybdenum, cobalt, tungsten, titanium,
chromium and mixtures thereof. Reference to the catalytically active
metal or metals is intended to encompass such metal or metals in
the elemental state or in some form such as an oxide, sulfide, halide,
carboxylate and the like. The hydrogenation catalyst is present
in an effective amount to provide the hydrogenation function of
the hydrocracking catalyst, and preferably in the range of from
0.05 to 25% by weight.
Dewaxing
SSZ-63 preferably predominantly in the hydrogen form, can be used
to dewax hydrocarbonaceous feeds by selectively removing straight
chain paraffins. Typically, the viscosity index of the dewaxed product
is improved (compared to the waxy feed) when the waxy feed is contacted
with SSZ-63 under isomerization dewaxing conditions.
The catalytic dewaxing conditions are dependent in large measure
on the feed used and upon the desired pour point. Hydrogen is preferably
present in the reaction zone during the catalytic dewaxing process.
The hydrogen to feed ratio is typically between about 500 and about
30000 SCF/bbl (standard cubic feet per barrel), preferably about
1000 to about 20000 SCF/bbl. Generally, hydrogen will be separated
from the product and recycled to the reaction zone. Typical feedstocks
include light gas oil, heavy gas oils and reduced crudes boiling
above about 350.degree. F.
A typical dewaxing process is the catalytic dewaxing of a hydrocarbon
oil feedstock boiling above about 350.degree. F. and containing
straight chain and slightly branched chain hydrocarbons by contacting
the hydrocarbon oil feedstock in the presence of added hydrogen
gas al a hydrogen pressure of about 15-3000 psi with a catalyst
comprising SSZ-63 and at least one Group VIII metal.
The SSZ-63 hydrodewaxing catalyst may optionally contain a hydrogenation
component of the type commonly employed in dewaxing catalysts. See
the aforementioned U.S. Pat. No. 4910006 and U.S. Pat. No. 5316753
for examples of these hydrogenation components.
The hydrogenation component is present in an effective amount to
provide an effective hydrodewaxing and hydroisomerization catalyst
preferably in the range of from about 0.05 to 5% by weight. The
catalyst may be run in such a mode to increase isomerization dewaxing
at the expense of cracking reactions.
The feed may be hydrocracked, followed by dewaxing. This type of
two stage process and typical hydrocracking conditions are described
in U.S. Pat. No. 4921594 issued May 1 1990 to Miller, which
is incorporated herein by reference in its entirety.
SSZ-63 may also be utilized as a dewaxing catalyst in the form
of a layered catalyst. That is, the catalyst comprises a first layer
comprising zeolite SSZ-63 and at least one Group VIII metal, and
a second layer comprising an aluminosilicate zeolite which is more
shape selective than zeolite SSZ-63. The use of layered catalysts
is disclosed in U.S. Pat. No. 5149421 issued Sep. 22 1992 to
Miller, which is incorporated by reference herein in its entirety.
The layering may also include a bed of SSZ-63 layered with a non-zeolitic
component designed for either hydrocracking or hydrofinishing.
SSZ-63 may also be used to dewax raffinates, including bright stock,
under conditions such as those disclosed in U.S. Pat. No. 4181598
issued Jan. 1 1980 to Gillespie et al., which is incorporated by
reference herein in its entirety.
It is often desirable to use mild hydrogenation (sometimes referred
to as hydrofinishing) to produce more stable dewaxed products. The
hydrofinishing step can be performed either before or after the
dewaxing step, and preferably after. Hydrofinishing is typically
conducted at temperatures ranging from about 190.degree. C. to about
340.degree. C. at pressures from about 400 psig to about 3000 psig
at space velocities (LHSV) between about 0.1 and 20 and a hydrogen
recycle rate of about 400 to 1500 SCF/bbl. The hydrogenation catalyst
employed must be active enough not only to hydrogenate the olefins,
diolefins and color bodies which may be present, but also to reduce
the aromatic content. Suitable hydrogenation catalyst are disclosed
in U.S. Pat. No. 4921594 issued May 1 1990 to Miller, which
is incorporated by reference herein in its entirety. The hydrofinishing
step is beneficial in preparing an acceptably stable product (e.g.,
a lubricating oil) since dewaxed products prepared from hydrocracked
stocks tend to be unstable to air and light and tend to form sludges
spontaneously and quickly.
Lube oil may be prepared using SSZ-63. For example, a C.sub.20+
lube oil may be made by isomerizing a C.sub.20+ olefin feed over
a catalyst comprising SSZ-63 in the hydrogen form and at least one
Group VIII metal. Alternatively, the lubricating oil may be made
by hydrocracking in a hydrocracking zone a hydrocarbonaceous feedstock
to obtain an effluent comprising a hydrocracked oil, and catalytically
dewaxing the effluent at a temperature of at least about 400.degree.
F. and at a pressure of from about 15 psig to about 3000 psig in
the presence of added hydrogen gas with a catalyst comprising SSZ-63
in the hydrogen form and at least one Group VIII metal.
Aromatics Formation
SSZ-63 can be used to convert light straight run naphthas and similar
mixtures to highly aromatic mixtures. Thus, normal and slightly
branched chained hydrocarbons, preferably having a boiling range
above about 40.degree. C. and less than about 200.degree. C., can
be converted to products having a substantial higher octane aromatics
content by contacting the hydrocarbon feed with a catalyst comprising
SSZ-63. It is also possible to convert heavier feeds into BTX or
naphthalene derivatives of value using a catalyst comprising SSZ-63.
The conversion catalyst preferably contains a Group VIII metal
compound to have sufficient activity for commercial use. By Group
VIII metal compound as used herein is meant the metal itself or
a compound thereof. The Group VIII noble metals and their compounds,
platinum, palladium, and iridium, or combinations thereof can be
used. Rhenium or tin or a mixture thereof may also be used in conjunction
with the Group VIII metal compound and preferably a noble metal
compound. The most preferred metal is platinum. The amount of Group
VIII metal present in the conversion catalyst should be within the
normal range of use in reforming catalysts, from about 0.05 to 2.0
weight percent, preferably 0.2 to 0.8 weight percent.
It is critical to the selective production of aromatics in useful
quantities that the conversion catalyst be substantially free of
acidity, for example, by neutralizing the zeolite with a basic metal,
e.g., alkali metal, compound. Methods for rendering the catalyst
free of acidity are known in the art. See the aforementioned U.S.
Pat. No. 4910006 and U.S. Pat. No. 5316753 for a description
of such methods.
The preferred alkali metals are sodium, potassium, rubidium and
cesium. The zeolite itself can be substantially free of acidity
only at very high silica:alumina mole ratios.
Catalytic Cracking
Hydrocarbon cracking stocks can be catalytically cracked in the
absence of hydrogen using SSZ-63 preferably predominantly in the
hydrogen form.
When SSZ-63 is used as a catalytic cracking catalyst in the absence
of hydrogen, the catalyst may be employed in conjunction with traditional
cracking catalysts, e.g., any aluminosilicate heretofore employed
as a component in cracking catalysts. Typically, these are large
pore, crystalline aluminosilicates. Examples of these traditional
cracking catalysts are disclosed in the aforementioned U.S. Pat.
No. 4910006 and U.S. Pat. No 5316753. When a traditional cracking
catalyst (TC) component is employed, the relative weight ratio of
the TC to the SSZ-63 is generally between about 1:10 and about 500:1
desirably between about 1:10 and about 200:1 preferably between
about 1:2 and about 50:1 and most preferably is between about 1:1
and about 20:1. The novel zeolite and/or the traditional cracking
component may be further ion exchanged with rare earth ions to modify
selectivity.
The cracking catalysts are typically employed with an inorganic
oxide matrix component. See the aforementioned U.S. Pat. No. 4910006
and U.S. Pat. No. 5316753 for examples of such matrix components.
Isomerization
The present catalyst is highly active and highly selective for
isomerizing C.sub.4 to C.sub.7 hydrocarbons. The activity means
that the catalyst can operate at relatively low temperature which
thermodynamically favors highly branched paraffins. Consequently,
the catalyst can produce a high octane product. The high selectivity
means that a relatively high liquid yield can be achieved when the
catalyst is run at a high octane.
The present process comprises contacting the isomerization catalyst,
i.e., a catalyst comprising SSZ-63 in the hydrogen form, with a
hydrocarbon feed under isomerization conditions. The feed is preferably
a light straight run fraction, boiling within the range of 30.degree.
F. to 250.degree. F. and preferably from 60.degree. F. to 200.degree.
F. Preferably, the hydrocarbon feed for the process comprises a
substantial amount of C.sub.4 to C.sub.7 normal and slightly branched
low octane hydrocarbons, more preferably C.sub.5 and C.sub.6 hydrocarbons.
It is preferable to carry out the isomerization reaction in the
presence of hydrogen. Preferably, hydrogen is added to give a hydrogen
to hydrocarbon ratio (H.sub.2 /HC) of between 0.5 and 10 H.sub.2
/HC, more preferably between 1 and 8 H.sub.2 /HC. See the aforementioned
U.S. Pat. No. 4910006 and U.S. Pat. No. 5316753 for a further
discussion of isomerization process conditions.
A low sulfur feed is especially preferred in the present process.
The feed preferably contains less than 10 ppm, more preferably less
than 1 ppm, and most preferably less than 0.1 ppm sulfur. In the
case of a feed which is not already low in sulfur, acceptable levels
can be reached by hydrogenating the feed in a presaturation zone
with a hydrogenating catalyst which is resistant to sulfur poisoning.
See the aforementioned U.S. Pat. No. 4910006 and U.S. Pat. No.
5316753 for a further discussion of this hydrodesulfurization
process.
It is preferable to limit the nitrogen level and the water content
of the feed. Catalysts and processes which are suitable for these
purposes are known to those skilled in the art.
After a period of operation, the catalyst can become deactivated
by sulfur or coke. See the aforementioned U.S. Pat. No. 4910006
and U.S. Pat. No. 5316753 for a further discussion of methods
of removing this sulfur and coke, and of regenerating the catalyst.
The conversion catalyst preferably contains a Group VIII metal
compound to have sufficient activity for commercial use. By Group
VIII metal compound as used herein is meant the metal itself or
a compound thereof. The Group VIII noble metals and their compounds,
platinum, palladium, and iridium, or combinations thereof can be
used. Rhenium and tin may also be used in conjunction with the noble
metal. The most preferred metal is platinum. The amount of Group
VIII metal present in the conversion catalyst should be within the
normal range of use in isomerizing catalysts, from about 0.05 to
2.0 weight percent, preferably 0.2 to 0.8 weight percent.
Alkylation and Transalkylation
SSZ-63 can be used in a process for the alkylation or transalkylation
of an aromatic hydrocarbon. The process comprises contacting the
aromatic hydrocarbon with a C.sub.2 to C.sub.16 olefin alkylating
agent or a polyalkyl aromatic hydrocarbon transalkylating agent,
under at least partial liquid phase conditions, and in the presence
of a catalyst comprising SSZ-63.
SSZ-63 can also be used for removing benzene from gasoline by alkylating
the benzene as described above and removing the alkylated product
from the gasoline.
For high catalytic activity, the SSZ-63 zeolite should be predominantly
in its hydrogen ion form. It is preferred that, after calcination,
at least 80% of the cation sites are occupied by hydrogen ions and/or
rare earth ions.
Examples of suitable aromatic hydrocarbon feedstocks which may
be alkylated or transalkylated by the process of the invention include
aromatic compounds such as benzene, toluene and xylene. The preferred
aromatic hydrocarbon is benzene. There may be occasions where naphthalene
or naphthalene derivatives such as dimethylnaphthalene may be desirable.
Mixtures of aromatic hydrocarbons may also be employed.
Suitable olefins for the alkylation of the aromatic hydrocarbon
are those containing 2 to 20 preferably 2 to 4 carbon atoms, such
as ethylene, propylene, butene-1 trans-butene-2 and cis-butene-2
or mixtures thereof. There may be instances where pentenes are desirable.
The preferred olefins are ethylene and propylene. Longer chain alpha
olefins may be used as well.
When transalkylation is desired, the transalkylating agent is a
polyalkyl aromatic hydrocarbon containing two or more alkyl groups
that each may have from 2 to about 4 carbon atoms. For example,
suitable polyalkyl aromatic hydrocarbons include di-, tri- and tetra-alkyl
aromatic hydrocarbons, such as diethylbenzene, triethylbenzene,
diethylmethylbenzene (diethyltoluene), di-isopropylbenzene, di-isopropyltoluene,
dibutylbenzene, and the like. Preferred polyalkyl aromatic hydrocarbons
are the dialkyl benzenes. A particularly preferred polyalkyl aromatic
hydrocarbon is di-isopropylbenzene.
When alkylation is the process conducted, reaction conditions are
as follows. The aromatic hydrocarbon feed should be present in stoichiometric
excess. It is preferred that molar ratio of aromatics to olefins
be greater than four-to-one to prevent rapid catalyst fouling. The
reaction temperature may range from 100.degree. F. to 600.degree.
F., preferably 250.degree. F. to 450.degree. F. The reaction pressure
should be sufficient to maintain at least a partial liquid phase
in order to retard catalyst fouling. This is typically 50 psig to
1000 psig depending on the feedstock and reaction temperature. Contact
time may range from 10 seconds to 10 hours, but is usually from
5 minutes to an hour. The weight hourly space velocity (WHSV), in
terms of grams (pounds) of aromatic hydrocarbon and olefin per gram
(pound) of catalyst per hour, is generally within the range of about
0.5 to 50.
When transalkylation is the process conducted, the molar ratio
of aromatic hydrocarbon will generally range from about 1:1 to 25:1
and preferably from about 2:1 to 20:1. The reaction temperature
may range from about 100.degree. F. to 600.degree. F., but it is
preferably about 250.degree. F. to 450.degree. F. The reaction pressure
should be sufficient to maintain at least a partial liquid phase,
typically in the range of about 50 psig to 1000 psig, preferably
300 psig to 600 psig. The weight hourly space velocity will range
from about 0.1 to 10. U.S. Pat. No. 5082990 issued on Jan. 21
1992 to Hsieh, et al. describes such processes and is incorporated
herein by reference.
Conversion of Paraffins to Aromatics
SSZ-63 can be used to convert light gas C.sub.2 -C.sub.6 paraffins
to higher molecular weight hydrocarbons including aromatic compounds.
Preferably, the zeolite will contain a catalyst metal or metal oxide
wherein said metal is selected from the group consisting of Groups
IB, IIB, VIII and IIIA of the Periodic Table. Preferably, the metal
is gallium, niobium, indium or zinc in the range of from about 0.05
to 5% by weight.
Xylene Isomerization
SSZ-63 may also be useful in a process for isomerizing one or more
xylene isomers in a C.sub.8 aromatic feed to obtain ortho-, meta-,
and para-xylene in a ratio approaching the equilibrium value. In
particular, xylene isomerization is used in conjunction with a separate
process to manufacture para-xylene. For example, a portion of the
para-xylene in a mixed C.sub.8 aromatics stream may be recovered
by crystallization and centrifugation. The mother liquor from the
crystallizer is then reacted under xylene isomerization conditions
to restore ortho-, meta- and para-xylenes to a near equilibrium
ratio. At the same time, part of the ethylbenzene in the mother
liquor is converted to xylenes or to products which are easily separated
by filtration. The isomerate is blended with fresh feed and the
combined stream is distilled to remove heavy and light by-products.
The resultant C.sub.8 aromatics stream is then sent to the crystallizer
to repeat the cycle.
Optionally, isomerization in the vapor phase is conducted in the
presence of 3.0 to 30.0 moles of hydrogen per mole of alkylbenzene
(e.g., ethylbenzene). If hydrogen is used, the catalyst should comprise
about 0.1 to 2.0 wt. % of a hydrogenation/dehydrogenation component
selected from Group VIII (of the Periodic Table) metal component,
especially platinum or nickel. By Group VIII metal component is
meant the metals and their compounds such as oxides and sulfides.
Optionally, the isomerization feed may contain 10 to 90 wt. of
a diluent such as toluene, trimethylbenzene, naphthenes or paraffins.
Oligomerization
It is expected that SSZ-63 can also be used to oligomerize straight
and branched chain olefins having from about 2 to 21 and preferably
2-5 carbon atoms. The oligomers which are the products of the process
are medium to heavy olefins which are useful for both fuels, i.e.,
gasoline or a gasoline blending stock and chemicals.
The oligomerization process comprises contacting the olefin feedstock
in the gaseous or liquid phase with a catalyst comprising SSZ-63.
The zeolite can have the original cations associated therewith
replaced by a wide variety of other cations according to techniques
well known in the art. Typical cations would include hydrogen, ammonium
and metal cations including mixtures of the same. Of the replacing
metallic cations, particular preference is given to cations of metals
such as rare earth metals, manganese, calcium, as well as metals
of Group II of the Periodic Table, e.g., zinc, and Group VIII of
the Periodic Table, e.g., nickel. One of the prime requisites is
that the zeolite have a fairly low aromatization activity, i.e.,
in which the amount of aromatics produced is not more than about
20% by weight. This is accomplished by using a zeolite with controlled
acid activity [alpha value] of from about 0.1 to about 120 preferably
from about 0.1 to about 100 as measured by its ability to crack
n-hexane.
Alpha values are defined by a standard test known in the art, e.g.,
as shown in U.S. Pat. No. 3960978 issued on Jun. 1 1976 to Givens
et al. which is incorporated totally herein by reference. If required,
such zeolites may be obtained by steaming, by use in a conversion
process or by any other method which may occur to one skilled in
this art.
Condensation of Alcohols
SSZ-63 can be used to condense lower aliphatic alcohols having
1 to 10 carbon atoms to a gasoline boiling point hydrocarbon product
comprising mixed aliphatic and aromatic hydrocarbon. The process
disclosed in U.S. Pat. No. 3894107 issued Jul. 8 1975 to Butter
et al., describes the process conditions used in this process, which
patent is incorporated totally herein by reference.
The catalyst may be in the hydrogen form or may be base exchanged
or impregnated to contain ammonium or a metal cation complement,
preferably in the range of from about 0.05 to 5% by weight. The
metal cations that may be present include any of the metals of the
Groups I through VIII of the Periodic Table. However, in the case
of Group IA metals, the cation content should in no case be so large
as to effectively inactivate the catalyst, nor should the exchange
be such as to eliminate all acidity. There may be other processes
involving treatment of oxygenated substrates where a basic catalyst
is desired.
Methane Upgrading
Higher molecular weight hydrocarbons can be formed from lower molecular
weight hydrocarbons by contacting the lower molecular weight hydrocarbon
with a catalyst comprising SSZ-63 and a metal or metal compound
capable of converting the lower molecular weight hydrocarbon to
a higher molecular weight hydrocarbon. Examples of such reactions
include the conversion of methane to C.sub.2+ hydrocarbons such
as ethylene or benzene or both. Examples of useful metals and metal
compounds include lanthanide and or actinide metals or metal compounds.
These reactions, the metals or metal compounds employed and the
conditions under which they can be run are disclosed in U.S. Pat.
No. 4734537 issued Mar. 29 1988 to Devries et al.; U.S. Pat.
No. 4939311 issued Jul. 3 1990 to Washecheck et al.; U.S. Pat.
No. 4962261 issued Oct. 9 1990 to Abrevaya et al.; U.S. Pat.
No. 5095161 issued Mar. 10 1992 to Abrevaya et al.; U.S. Pat.
No. 5105044 issued Apr. 14 1992 to Han et al.; U.S. Pat. No.
5105046 issued Apr. 14 1992 to Washecheck; U.S. Pat. No. 5238898
issued Aug. 24 1993 to Han et al.; U.S. Pat. No. 5321185 issued
Jun. 14 1994 to van der Vaart; and U.S. Pat. No. 5336825 issued
Aug. 9 1994 to Choudhary et al., each of which is incorporated
herein by reference in its entirety.
EXAMPLES
The following examples demonstrate but do not limit the present
invention.
Example 1
Synthesis of the Structure-Directing Agent A (N-cyclodecyl-N-methyl-pyrrolidinium
cation)
##STR1##
The anion (X.sup.-) associated with the cation may be any anion
which is not detrimental to the formation of the zeolite. Representative
anions include halogen, e.g., fluoride, chloride, bromide and iodide,
hydroxide, acetate, sulfate, tetrafluoroborate, carboxylate, and
the like. Hydroxide is the most preferred anion.
The structure-directing agent (SDA) N-cyclodecyl-N-methyl-pyrrolidinium
cation was synthesized according to the procedure described below
(see Scheme 1). To a solution of cyclodecanone (25 gm; 0.16 mol)
in 320 ml anhydrous hexane in a three-necked round bottom flask
equipped with a reflux condenser and a mechanical stirrer, 34 gm
of pyrrolidine (0.48 mol) and 48 gm (0.4 mol) anhydrous magnesium
sulfate were added. The resulting mixture was stirred while heating
at reflux for five days. The reaction mixture was filtered through
a fritted-glass funnel. The filtrate was concentrated at reduced
pressure on a rotary evaporator to yield 32 gm (96%) of the expected
enamine (1-cyclodec-1-enyl-pyrrolidine) as a reddish oily substance.
.sup.1 H-NMR and .sup.13 C-NMR spectra were acceptable for the desired
product. The enamine was reduced to the corresponding amine (N-cyclodecyl-pyrrolidine)
in quantitative yield via catalytic hydrogenation in the presence
of 10% Pd on activated carbon at hydrogen pressure of 55 PSI in
ethanol.
Quaternization of N-cyclodecyl-pyrrolidine with Methyl Iodide (Synthesis
of N-cyclodecyl-N-methyl-pyrrolidinium iodide)
To a solution of 30 gm (0.14 mol.) of N-cyclodecyl-pyrrolidine
in 250 ml anhydrous methanol in a one liter reaction flask, 30 gm
(0.21 mol.) of methyl iodide was added. The reaction mixture was
mechanically stirred for 48 hours at room temperature. Then, a 0.5
mole equivalent of methyl iodide was added and the mixture was heated
to reflux and refluxed for 30 minutes. The reaction mixture was
then cooled down and concentrated under reduced pressure on a rotary
evaporator to give the product as a pale yellow solid material.
The product was purified by dissolving in acetone and then precipitating
by adding diethyl ether. The recrystallization yielded 46 gm (93%)
of the pure N-cyclodecyl-N-methyl-pyrrolidinium iodide. .sup.1 H-NMR
and .sup.13 C-NMR were ideal for the product.
Ion Exchange (Synthesis of N-cyclodecyl-N-methyl-pyrrolidinium
hydroxide)
N-cyclodecyl-N-methyl-pyrrolidinium iodide (45 gm; 0.128 mol) was
dissolved in 150 ml water in a 500 ml plastic bottle. To the solution,
160 gm of Ion-Exchange Resin-OH (BIO RAD.RTM. AHI-X8) was added
and the mixture was stirred at room temperature overnight. The mixture
was filtered and the solids were rinsed with an additional 85 ml
of water. The reaction afforded 0.12 mole of the SDA (N-cyclodecyl-N-methyl-pyrrolidinium
hydroxide) as indicated by titration analysis with 0.1N HCl. ##STR2##
Example 2
Synthesis of Borosilicate SSZ-63
A 23 cc Teflon liner was charged with 4.9 gm of 0.61M aqueous solution
of N-cyclodecyl-N-methyl-pyrrolidinium hydroxide (3 mmol SDA), 1.2
gm of 1M aqueous solution of NaOH (1.2 mmol NaOH) and 5.9 gm of
de-ionized water. To this mixture, 0.06 gm of sodium borate decahydrate
(0.157 mmol of Na.sub.2 B.sub.4 O.sub.7.10H.sub.2 O; .about.0.315
mmol B.sub.2 O.sub.3) was added and stirred until completely dissolved.
To this solution, 0.9 gm of CABO-SIL M-5.RTM. fumed silica (.about.14.7
mmol SiO.sub.2) was added and thoroughly stirred by hand. The resulting
gel was capped off and placed in a Parr steel autoclave and heated
in an oven at about 160.degree. C. while tumbling at about 43 rpm.
The reaction was monitored by periodically monitoring the pH of
the gel, and by looking for crystal growth using scanning electron
microscopy (SEM). Once the crystallization was completed, after
heating for 12 days at the conditions described above, the starting
reaction gel turned into a clear liquid layer and a fine powdery
precipitate. The mixture was filtered through a fritted-glass funnel.
The collected solids were thoroughly washed with water and, then,
rinsed with acetone (.about.20 ml) to remove any organic residues.
The solids were allowed to air-dry over night and, then, dried in
an oven at 120.degree. C. for 1hour. The reaction afforded 0.85
gram of SSZ-63. The originality of SSZ-63 was determined from its
unique XRD pattern, and by transmission electron microscopy analysis
Example 3
Conversion of Borosilicate SSZ-63 to Aluminosilicate SSZ-63
Borosilicate SSZ-63 synthesized as described in Example 2 above
and calcined as shown in Example 17 below was suspended in 1M solution
of aluminum nitrate nonahydrate (15 ml of 1M Al(NO.sub.3).sub.3.9H.sub.2
O soln./1 gm zeolite). The suspension was heated at reflux for 48
hours. The mixture was then filtered and the collected solids were
thoroughly rinsed with water and air-dried overnight. The solids
were further dried in an oven at 120.degree. C. for 2 hours.
Example 4
Synthesis of Germanosilicate SSZ-63
A 23 cc Teflon liner was charged with 4.85 gm of 0.61M aqueous
solution of N-cyclodecyl-N-methyl-pyrrolidinium hydroxide (3 mmol
SDA), 1.25 gm of 1M aqueous solution of NaOH (1.25 mmol NaOH) and
5.8 gm of de-ionized water. To this mixture, 0.25 gm of GeO.sub.2
(2.39 mmol) was added and stirred until completely dissolved. To
this solution, 0.7 gm of CAB-O-SIL M-5.RTM. (.about.11.4 mmol SiO.sub.2)
was added and thoroughly stirred by hand. The resulting gel was
capped off and placed in a Parr steel autoclave and heated in an
oven at about 160.degree. C. while tumbling at about 43 rpm. The
reaction was monitored by periodically monitoring the pH of the
gel, and by looking for crystal growth using scanning electron microscopy
(SEM). Once the crystallization was completed, after heating for
six days, the starting reaction gel turned into a clear liquid layer
and a fine powdery precipitate. The mixture was filtered through
a fritted-glass funnel. The collected solids were thoroughly washed
with water and, then, rinsed with acetone (.about.20 ml) to remove
any organic residues. The solids were allowed to air-dry over night
and, then, dried in an oven at 120.degree. C. for one hour. The
reaction afforded 0.73 gram of SSZ-63.
Examples 5-16
Synthesis of Borosilicate SSZ-63
SSZ-63 was synthesized at varying SiO.sub.2 /B.sub.2 O.sub.3 ratios
in the starting synthesis gel. This was accomplished by using the
synthetic conditions described in Example 2 keeping everything the
same-while changing the SiO.sub.2 /B.sub.2 O.sub.3 ratios in the
starting gel. This was done by keeping the amount of CAB-O-SIL M-5.RTM.
(the source of SiO.sub.2) constant while varying the amount of sodium
borate decahydrates added in each run. Consequently, varying the
amount of sodium borate decahydrates led to varying the SiO.sub.2
/Na ratios in the starting gels. The table below shows the SiO.sub.2
/B.sub.2 O.sub.3 and SiO.sub.2 /Na ratios and the observed products
for each run.
Example 17
Calcination of SSZ-63
The material from Example 3 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 five hours, after which it is increased to 594.degree. C. and
held there for another five hours. A 50/50 mixture of air and nitrogen
is passed over the SSZ-63 at a rate of 20 standard cubic feet per
minute during heating.
Example 18
NH.sub.4 Exchange
Ion exchange of calcined SSZ-63 material (as prepared in Example
2 and calcined as in Example 17) is performed using NH.sub.4 NO.sub.3
to convert the SSZ-63 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.4 NO3 as SSZ-63 is slurried in water at a ratio of 25-50:1
water to SSZ-63. The exchange solution is heated at 95.degree. C.
for two hours and then filtered. This procedure can be repeated
up to three times. Following the final exchange, the SSZ-63 is washed
several times with water and dried. This NH.sub.4.sup.+ form of
SSZ-63 can then be converted to the H.sup.+ form by calcination
(as described in Example 17) to 540.degree. C.
Example 19
Constraint Index Determination
The hydrogen form of the SSZ-63 of Example 2 (after treatment according
to Examples 17 3 and 18) 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 molecular sieve 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 315.degree. C., 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 ten minutes of feed introduction.
The Constraint Index value is calculated from the gas chromatographic
data using methods known in the art. SSZ-63 has a Constraint Index
of 1.1 after 10 minutes at 315.degree. C. with 87.7% feed conversion.
The Constraint Index dropped with time on stream (0.6 at 100 minutes)
suggesting that SSZ-63 is a large pore molecular sieve.
Example 20
Hydrocracking of n-Hexadecane
A sample of SSZ-63 as prepared in Example 2 was treated as in Examples
17 3 and 18. Then a sample was slurried in water and the pH of
the slurry was adjusted to a pH of .about.10 with dilute ammonium
hydroxide. To the slurry was added a solution of Pd(NH.sub.3).sub.4
(NO.sub.3).sub.2 at a concentration which would provide 0.5 wt.
% Pd with respect to the dry weight of the molecular sieve sample.
This slurry was stirred for 48 hours at 100.degree. C. After cooling,
the slurry was filtered through a glass frit, washed with de-ionized
water, and dried at 100.degree. C. The catalyst was then calcined
slowly up to 482.degree. C. in air and held there for three hours.
The calcined catalyst was pelletized in a Carver Press and crushed
to yield particles with a 20/40 mesh size range. Sized catalyst
(0.5 g) was packed into a 1/4 inch OD tubing reactor in a micro
unit for n-hexadecane hydroconversion. The table below gives the
run conditions and the products data for the hydrocracking test
on n-hexadecane. After the catalyst was tested with n-hexadecane,
it was titrated using a solution of butyl amine in hexane. The temperature
was increased and the conversion and product data evaluated again
under titrated conditions. The results shown in the table below
show that SSZ-63 is effective as a hydrocracking catalyst.
Temperature 500.degree. F. (260.degree. C.) 560.degree. F. (293.degree.
C.) Time-on-Stream (hrs.) 6.1-7.1 47.6-50.1 WHSV 1.55 1.55 PSIG
1200 1200 Titrated? No Yes n-16 % Conversion 100 96.5 Hydrocracking
Conv. 93.4 34.95 Isomerization Selectivity, % 6.6 63.8 Cracking
Selectivity, % 93.4 36.2 C4-, % 8.8 31.85 C5/C4 9.6 12.85 C5 + C6/C5
% 23.34 18.1 DMB/MP 0.12 0.07 C4-C13 i/n yield 6.98 4.88 C7-C13
yield 64.84 26.6
Example 21
Argon Adsorption Analysis
SSZ-63 has a micropore volume of 0.22 cc/gm based on argon adsorption
isotherm at 87.6 K recorded on ASAP 2010 equipment from Micromerities.
The low-pressure dose was 3.00 cm.sup.3 /g (STP) with 15-s equilibration
interval. The argon adsorption isotherm was analyzed using the density
function theory (DFT) formalism and parameters developed for activated
carbon slits by Olivier (Porous Mater., 1995 2 9) using the Saito
Foley adaptation of the Horvarth-Kawazoe formalism (Microporous
Materials, 1995 3 531) and the conventional t-plot method (J.
Catalysis, 1965 4 319). Analogous measurements were made with
nitrogen using the Digisorb system. |