Molecular sieve abstract
This invention relates to a novel synthetic crystalline molecular
sieve composition, MCM-37 which may contain framework +3 valence
element, e.g. aluminum, and +5 valence element, e.g. phosphorus
or with an addition +4 valence element, e.g. silicon, and to use
thereof as a support and in catalytic conversion of organic compounds.
The crystalline composition of this invention can easily be converted
to catalytically active material.
Molecular sieve claims
What is claimed is:
1. A composition of matter comprising crystals having a framework
topology giving an x-ray diffraction pattern with interplanar d-spacings
at 16.41.+-.0.59 Angstroms, 14.12.+-.0.45 Angstroms and 5.68.+-.0.08
Angstroms and without a significant interplanar d-spacing at 13.6-13.3
Angstroms, said crystals having pore windows framed by 14 tetrahedral
members.
2. The composition of claim wherein said crystals have a framework
topology giving an X-ray diffraction pattern substantially as shown
in Table 1B.
3. The composition of claim 1 wherein said crystals have a framework
topology giving an X-ray diffraction pattern substantially as shown
in Table 1C.
4. A composition of matter comprising crystals having a composition,
on an anhydrous basis, as follows:
wherein X is aluminum, Y is phosphorus, Z is silicon, M is a cation
of valence m, N is an anion of valence n, and x and y are numbers
of from greater than -1 to less than +1 which satisfy the relationships:
(1) if x is O, then y is not O,
(2) if y is O, then x is not O, and
(3) x+y is greater than 0.001 and less than 1
said crystals having pore windows formed by 14 tetrahedral members.
5. The composition of claim 4 wherein said crystals have a framework
topology giving an X-ray diffraction pattern with interplanar d-spacings
at 16.41.+-.0.59 Angstroms, 14.12.+-.0.45 Angstroms, and 5.68.+-.0.08
Angstroms and without an interplanar d-spacing at 13.6-13.3 Angstroms.
6. The composition of claim 4 wherein M is selected from the group
consisting of di-n-butylamine, and onium compounds of tetra propylammonium
and tetrabutylammonium.
7. A composition of matter comprising crystals having a framework
topology giving an X-ray diffraction pattern with interplanar d-spacings
at 16.41.+-.0.59 Angstroms, 14.12.+-.0.45 Angstroms and 5.68.+-.0.08
Angstroms, and without a significant interplanar d-spacing at 13.6-13.3
Angstroms, said crystals having pore windows framed by 14 tetrahedral
members, having been synthesized by the method comprising:
(1) providing a reaction mixture comprising sources of X oxide,
Y oxide and Z oxide, wherein X represents aluminum, Y represents
phosphorus, and Z represents silicon, an organic directing agent
D selected from the group consisting of tetrapropylammonium hydroxide,
tetrabutylammonium hydroxide, tetrapropylammonium bromide, tetrabutylammonium
bromide and di-n-butylamine, inorganic ions M, and water, the components
of said reaction mixture having the following relationship:
where a, b, c, d, e, f, g, and h are numbers satisfying the following
relationships:
a/(c+d+e) is less than 4
b/(c+d+e) is less than 2
d/(c+e) is less than 2
f/(c+d+e) is from 0.1 to 15
g/(c+d+e) is less than 2 and
h/(c+d+e) is from 3 to 150
(2) heating said reaction mixture at a rate of from 5.degree. C.
to 200.degree. C. per hour to a temperature of from 80.degree. C.
to 300.degree. C.;
(3) maintaining said reaction mixture at a temperature of from
80.degree. C. to 300.degree. C. and a pH of from 2 to 9 until crystals
of said composition of matter are formed; and
(4) recovering from said reaction mixture said composition of matter.
8. The composition of matter of claim 7 having been synthesized
by a method which further comprises calcining the recovered composition
of matter.
9. The composition of matter of claim 7 having been synthesized
by a method which further comprises calcining the recovered composition
of matter in the presence of water.
10. The recovered composition of claim 7 characterized in the anhydrous
state, as follows:
wherein D' represents the total of organic directing agent D plus
organic solvent, v is the number of moles of D', m is the valence
of cation M, n is the valence of anion N, and x and y are numbers
of from greater than -1 to less than +1 which satisfy the relationships:
(1) if x is 0 then y is not 0
(2) if y is 0 then x is not 0 and
(3) x+y is greater than 0.001 and less than 1.
11. The composition of claim 7 wherein said crystals have a framework
topology giving an X-ray diffraction pattern substantially as shown
in Table 1B.
12. The composition of claim 7 wherein said crystals have a framework
topology giving an X-ray diffraction pattern substantially shown
in Table 1C.
13. A process for effecting catalytic conversion of an organic
compound-containing feedstock which comprises contacting said feedstock
under catalytic conversion conditions with a catalyst comprising
an active form of the composition of claim 1.
14. A process for effecting catalytic conversion of an organic
compound-conversion feedstock which comprises contacting said feedstock
under catalytic conversion conditions with a catalyst comprising
an active form of the composition of claim 4.
Molecular sieve description
BACKGROUND OF THE INVENTION
This invention relates to a novel synthetic crystalline molecular
sieve material, MCM-37 which may contain framework +3 valence element,
e.g. aluminum and +5 valence element, e.g. phosphorus, or with an
additional +4 valence element, e.g. silicon, and to use thereof
in catalytic conversion of organic compounds. The crystalline material
can easily be converted to catalytically active material. It can
also be used as a support material.
DESCRIPTION OF THE PRIOR ART
Zeolitic materials, both natural and synthetic, have been demonstrated
in the past to have catalytic properties for various types of hydrocarbon
conversion. Certain zeolitic materials are ordered, porous crystalline
aluminosilicates having a definite crystalline structure as determined
by X-ray diffraction, within which there are a large number of smaller
cavities which may be interconnected by a number of still smaller
channels or pores. These cavities and pores are uniform in size
within a specific zeolitic material. Since the dimensions of these
pores are such as to accept for adsorption molecules of certain
dimensions while rejecting those of larger dimensions, these materials
have come to be known as "molecular sieves" and are utilized
in a variety of ways to take advantage of these properties.
Such molecular sieves, both natural and synthetic, include a wide
variety of positive ion-containing crystalline silicates. These
silicates can be described as a rigid three-dimensional framework
of SiO.sub.4 and Periodic Table Group IIIB element oxide, e.g. AlO.sub.4
in which the tetrahedra are cross-linked by the sharing of oxygen
atoms whereby the ratio of the total Group IIIB element, e.g. aluminum,
and silicon atoms to oxygen atoms is 1:2. The electrovalence of
the tetrahedra containing the Group IIIB element is balanced by
the inclusion in the crystal of a cation, for example, an alkali
metal or an alkaline earth metal cation. This can be expressed wherein
the ratio of the Group IIIB element to the number of various cations,
such as Ca/2 Sr/2 Na, K or Li, is equal to unity. One type of
cation may be exchanged either entirely or partially with another
type of cation utilizing ion exchange techniques in a conventional
manner. By means of such cation exchange, it has been possible to
vary the properties of a given silicate by suitable selection of
the cation. The spaces between the tetrahedra are occupied by molecules
of water prior to dehydration.
Prior art techniques have resulted in the formation of a great
variety of synthetic zeolites. Many of these zeolites have come
to be designated by letter or other convenient symbols, as illustrated
by zeolite A (U.S. Pat. No. 2882243), zeolite X (U.S. Pat. No.
2882244), zeolite Y (U.S. Pat. No. 3130007), zeolite ZK-5 (U.S.
Pat. No. 3247195), zeolite ZK-4 (U.S. Pat. No. 3314752), zeolite
ZSM-5 (U.S. Pat. No. 3702886), zeolite ZSM-11 (U.S. Pat. No. 3709979),
zeolite ZSM-12 (U.S. Pat. No. 3832449), zeolite ZSM-20 (U.S. Pat.
No. 3972983), ZSM-35 (U.S. Pat. No. 4016245), and zeolite ZSM-23
(U.S. Pat. No. 4076842), merely to name a few.
The SiO.sub.2 /Al.sub.2 O.sub.3 ratio of a given zeolite is often
variable. For example, zeolite X can be synthesized with SiO.sub.2
/Al.sub.2 O.sub.3 ratios of from 2 to 3; zeolite Y, from 3 to about
6. In some zeolites, the upper limit of the SiO.sub.2 /Al.sub.2
O.sub.3 ratio is unbounded. ZSM-5 is one such example wherein the
SiO.sub.2 /Al.sub.2 O.sub.3 ratio is at least 5 and up to the limits
of present analytical measurement techniques. U.S. Pat. No. 3941871
(Re. 29948) discloses a porous crystalline silicate made from a
reaction mixture containing no deliberately added alumina in the
recipe and exhibiting the X-ray diffraction pattern characteristic
of ZSM-5. U.S. Pat. Nos. 4061724 4073865 and 4104294 describe
crystalline silicate of varying alumina and metal content.
Aluminum phosphates are taught, for example, in U.S. Pat. Nos.
4310440 and 4385994. These aluminum phosphate materials have
essentially electroneutral lattices. U.S. Pat. No. 3801704 teaches
an aluminum phosphate treated in a certain way to impart acidity.
Aluminophosphates are also described by Wilson, S. T. et al. in
the Journal of the American Chemical Society 104 1146-1147 (1982).
An early reference to a hydrated aluminum phosphate which is crystalline
until heated at about 110.degree. C., at which point it becomes
amorphous, is the "H.sub.1 " phase or hydrate of aluminum
phosphate of F.d'Yvoire, Memoir Presented to the Chemical Society.
No. 392 "Study of Aluminum Phosphate and Trivalent Iron",
July 6 1961 (received), pp. 1762-1776. This material, when crystalline,
is identified by the Joint Commission for Powder Diffraction Standards
(JCPDS), card number 15-274. Once heated at about 110.degree. C.,
however, the d'Yvoire material becomes amorphous or transforms to
the aluminophosphate form of tridymite.
A naturally occurring, highly hydrated basic ferric oxyphosphate
mineral, cacoxenite, is reported by Moore and Shen, Nature, Vol.
306 No. 5941 pp. 356-358 (1983) to have a framework structure
containing very large channels with a calculated free pore diameter
of 14.2 Angstroms. R. Szostak et al., Zeolites: Facts, Figures,
Future, Elsevier Science Publishers B.V., 1989 present work showing
cacoxenite as being very hydrophilic, i.e. adsorbing non-polar hydrocarbons
only with great difficulty. Their work also shows that thermal treatment
of cacoxenite causes an overall decline in X-ray peak intensity.
Silicoaluminophosphates of various structures are taught in U.S.
Pat. No. 4440871. Aluminosilicates containing phosphorus, i.e.
silicoaluminophosphates of particular structures are taught in U.S.
Pat. Nos. 3355246 (i.e. ZK-21) and 3791964 (i.e. ZK-22). Other
teachings of silicoaluminophosphates and their synthesis include
U.S. Pat. Nos. 4673559 (two-phase synthesis method); 4880611
(MCM-9); 4623527 (MCM-10); 4639358 (MCM-1); 4647442 (MCM-2);
4664897 (MCM-4); and 4632811 (MCM-3).
A method for synthesizing crystalline metalloaluminophosphates
is shown in U.S. Pat. No. 4713227 and an antimonophosphoaluminate
and the method for its synthesis are taught in U.S. Pat. No. 4619818.
U.S. Pat. No. 4567029 teaches metalloaluminophosphates, and titaniumaluminophosphate
and the method for its synthesis are taught in U.S. Pat. No. 4500651.
The phosphorus-substituted zeolites of Canadian Patents 911416;
911417; and 911418 are referred to as "aluminosilicophosphate"
zeolites. Some of the phosphorus therein appears to be occluded,
not structural.
U.S. Pat. No. 4363748 describes a combination of silica and aluminum-calcium-cerium
phosphate as a low acid activity catalyst for oxidative dehydrogenation.
Great Britain Pat. No. 2068253 discloses a combination of silica
and aluminum-calcium-tungsten phosphate as a low acid activity catalyst
for oxidative dehydrogenation. U.S. Pat. No. 4228036 teaches an
alumina-aluminum phosphate-silica matrix as an amorphous body to
be mixed with zeolite for use as cracking catalyst. U.S. Pat. No.
3213035 teaches improving hardness of aluminosilicate catalysts
by treatment with phosphoric acid. The catalysts are amorphous.
Other references teaching aluminum phosphates include U.S. Pat.
Nos. 4365095; 4361705; 4222896; 4210560; 4179358; 4158621;
4071471; 4014945; 3904550 and 3697550. Since their neutral
framework structure is essentially void of ion-exchange properties,
they are used as catalyst supports or matrices.
For a period of time, the largest molecular sieves contained 12-membered
rings with an associated pore opening of about 7.4 .ANG.. Recently,
however, the search for larger pore molecular sieves resulted in
the discovery of molecular sieves with pores larger than that of
12-membered rings. It is also well known that each molecular sieve
has a distinctive X-ray diffraction pattern.
U.S. Pat. No. No. 4310440 describes aluminophosphates including
a structure designated AlPO.sub.4 -8 which has a distinctive X-ray
diffraction pattern having a significant interplanar d-spacing at
13.6-13.3 Angstroms. AlPO.sub.4 -8 is believed to have a 14-membered
ring.
Davis, et al. describe an aluminophosphate-based molecular sieve
with an 18-membered ring designated VPI-5 Nature 331 362-366 (1988)).
U.S. Pat. No. No. 4880611 discloses a synthetic crystalline molecular
sieve composition, MCM-9 which may contain framework +3 valence
element, e.g. aluminum, +4 valence element, e.g. silicon, and +5
valence element, e.g. phosphorus. Its crystals have pore windows
of about 12-13 Angstroms in diameter formed by 18 tetrahedral members
and after heating at 110.degree. C. or higher, display an X-ray
diffraction pattern with interplanar d-spacings at 16.4.+-.0.2
8.2.+-.0.1 6.21.+-.0.05 6.17.+-.0.05 5.48.+-.0.05 and 4.74.+-.0.05
Angstroms without a significant interplanar d-spacing at 13.6-13.3
Angstroms.
SUMMARY OF THE INVENTION
The present invention is directed to a novel synthetic crystalline
molecular sieve composition comprising a crystal having a framework
topology giving a certain X-ray diffraction pattern which may contain
one or more +3 valence elements, +5 valence elements and which may
also include +4 valence elements and to its use as a support or
as a catalyst component in catalytic conversion of organic, e.g.
hydrocarbon, compounds.
The anhydrous crystalline composition of this invention has the
general chemical formula:
wherein X is the +3 valence element, Y is the +5 valence element,
Z is the +4 valence element, M is a cation of valence m, N is an
anion of valence n, and x and y are numbers of from greater than
-1 to less than +1 which satisfy the relationships:
(1) if x is 0 then y is not 0
(2) if y is 0 then x is not 0 and
(3) x+y is greater than 0.001 and less than 1.
In the composition above, when x is greater than y, the present
composition is a cation exchanger with potential use as an acidic
catalyst. When x is less than y, it is an anion exchanger with potential
use as a basic catalyst.
In the synthesized form of the present composition, it can also
contain occluded organic material, D', and water molecules, entrapped
during the synthesis and filling the microporous voids. It then
has the general formula:
wherein v is the number of moles of D', occluded organic material
resulting from organic directing agent (D), and/or solvent used
in synthesis of and filling microporous voids of the composition,
which material may be removed upon calcination, w is moles of H.sub.2
O, e.g. from 0 to about 5 and x and y are the numbers defined above.
The MCM-37 crystalline material in the as-synthesized form has a
characteristic x-ray diffraction pattern as set forth in Table 1A.
The present invention is a unique composition of matter which can
be adjusted to exhibit a valuable combination of catalytic, sorption
and ion-exchange properties and is also useful in fulfilling a support
function.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the X-ray diffraction pattern of the Example 1 product.
FIG. 2 shows the X-ray diffraction pattern of the Example 2 product.
FIG. 3 shows the X-ray diffraction pattern of the Example 3 product.
DETAILED DESCRIPTION OF THE INVENTION
The composition of the present invention may comprise one or more
+3 valence elements, such as those selected from the group consisting
of aluminum, iron, chromium, vanadium, molybdenum, arsenic, antimony,
manganese, gallium and boron; one or more +5 valence elements, such
as those selected from the group consisting of phosphorus, arsenic,
antimony and vanadium, and optionally one or more +4 valence elements,
such as those selected from the group consisting of silicon, germanium
and titanium in the structure thereof.
The composition of the present invention will exhibit unique and
useful catalytic, sorptive and shape selective properties along
with the presence of a +4 valence element/(+3 valence element plus
+5 valence element), e.g. silicon/(aluminum+phosphorus), atomic
ratio of less than unity, but greater than zero, e.g. from about
0.001 to 0.99. It is well recognized that aluminum phosphates exhibit
a phosphorus/aluminum atomic ratio of only 0.8 to 1.2 and contain
essentially no structural silicon. Also, the phosphorus-substituted
zeolite compositions, sometimes referred to as "aluminosilicophosphate
zeolites", have a silicon/aluminum atomic ratio of from 0.66
to 8.0 and a phosphorus/aluminum atomic ratio of from greater than
0 to 1.0.
The original cations of the as-synthesized present composition
can be replaced in accordance with techniques well known in the
art, at least in part, by ion exchange with other cations. Preferred
replacing cations include metal ions, hydrogen ions, hydrogen precursor,
e.g. ammonium, ions and mixtures thereof. Particularly preferred
cations are those which render the composition catalytically active
or control catalytic activity, especially for hydrocarbon conversion.
These include hydrogen, rare earth metal and metals of Groups IA,
IIA, IIIA, IVA, IB, IIB, IIIB, IVB, VIB and VIII of the Periodic
Table of the Elements.
Typical ion exchange technique would be to contact the synthetic
present composition with a salt of the desired replacing cation
or cations. Examples of such salts include the halides, e.g. chlorides,
nitrates and sulfates.
Framework topologies of the present composition containing +5 valence
element, e.g. phosphorus, and +3 valence element, e.g. aluminum,
in tetrahedrally coordinated structural positions along with which
+4 valence element, e.g. silicon which may be present are not those
of layered materials, but are rigid 3-dimensional crystals.
The crystalline composition of the present invention can be beneficially
thermally treated, either before or after ion exchange. This thermal
treatment is performed by heating the composition in an atmosphere
such as air, nitrogen, hydrogen, steam, etc., at a temperature of
from about 300.degree. C. to about 1100.degree. C., preferably from
about 350.degree. C. to about 750.degree. C., for from about 1 minute
to about 20 hours. While subatmospheric or superatmospheric pressures
may be used for this thermal treatment, atmospheric pressure is
desired for reasons of convenience.
The X-ray diffraction lines in Tables 1A, 1B and 1C identify a
crystal framework topology in the composition exhibiting large pore
windows of approximately 14-membered ring size. The pores are at
least about 8.5-9.0 Angstroms in diameter. These lines distinguish
this topology from other crystalline aluminosilicate, aluminophosphate
and silicoaluminophosphate structures. It is noted that the X-ray
pattern of the present composition is void of a d-spacing value
at 13.6-13.3 Angstroms with any significant intensity relative the
strongest d-spacing value. If a d-spacing value in this range appears
in a sample of the present composition, it is due to impurity and
will have a weak relative intensity. The large pore "AlPO.sub.4
-8" of U.S. Pat. No. 4310440 has a d-spacing value at 13.6-13.3
Angstroms with medium-very strong relative intensity as reported
in the patent.
These X-ray diffraction data were collected with conventional X-ray
systems, using copper K-alpha radiation. The positions of the peaks,
expressed in degrees 2 theta, where theta is the Bragg angle, were
determined by scanning 2 theta. The interplanar spacings, d, measured
in Angstrom units (A), and the relative intensities of the lines,
I/I.sub.o, where I.sub.o is one-hundredth of the intensity of the
strongest line, including subtraction of the background, were derived
from the experimental X-ray diffraction pattern. It should be understood
that this X-ray diffraction pattern is characteristic of all the
species of the present compositions. Ion exchange of cations with
other ions results in a composition which reveals substantially
the same X-ray diffraction pattern with some minor shifts in interplanar
spacing and variation in relative intensity. Relative intensity
of individual lines may also vary relative the strongest line when
the composition is chemically treated, such as by dilute acid treatment.
Other variations can occur, depending on the +4 valence element/+3
valence element, e.g. silicon/aluminum, and the +5 valence element/+3
valence element, e.g. phosphorus/aluminum, ratios of the particular
sample, as well as its degree of thermal treatment. The relative
intensities of the lines are also susceptible to changes by factors
such as sorption of water, hydrocarbons or other components in the
channel structure. Further, the optics of the X-ray diffraction
equipment can have significant effects on intensity, particularly
in the low angle region. Intensities may also be affected by preferred
crystallite orientation.
The computed X-ray powder diffraction pattern of MCM-37 based on
a structural model is shown in Table 1D. This structural model may
not be correct in all respects but a theoretical X-ray powder pattern
computed from the model reproduces the d-spacings and intensities
observed on the experimental X-ray pattern to within the expected
limits.
Reaction conditions may comprise carefully heating the above reaction
mixture at a rate of from 5.degree. C. to 200.degree. C. per hour
to a temperature of from about 80.degree. C. to about 300.degree.
C. for a period of time of from about 5 hours to about 500 hours
until crystals of the present composition are formed. A more preferred
temperature rang is from about 100.degree. C. to about 200.degree.
C. with the amount of time at a temperature in such range being
from about 15 hours to about 168 hours. During heating and maintaining
the reaction mixture at the desired temperature, the pH must be
carefully controlled to be from about 2 to about 12. Control of
pH can be accomplished by adjusting the concentration of the added
organic and/or inorganic base(s).
The reaction is carried out until crystals of the desired composition
form. The crystalline product is recovered by separating same from
the reaction medium, as by cooling the whole to room temperature,
filtering and washing with water before drying.
A two-phase system may also be used as described in U.S. Pat. No.
No. 4647442 which is incorporated herein by reference. In a two-phase
system, the reaction mixture composition can be prepared utilizing
materials which supply the appropriate components. In a two-phase
system, the aqueous phase components may include from the sources
of the +3 +4 or +5 valence elements, e.g. silicon, phosphorus,
or aluminum, those not included in the water-immiscible, e.g. organic,
phase. The organic phase comprises an organic solvent and a source
of at least one of the +3 +4 or +5 valence elements, e.g. silicon,
phosphorus, or aluminum, insoluble in the aqueous phase under reaction
conditions. The aqueous phase also contains the required directing
agent.
In either system, useful sources of +3 valence element, e.g. aluminum,
as non-limiting examples, include any known form of oxide or hydroxide,
organic or inorganic salt or compound. Useful sources of +4 valence
element, e.g. silicon, include, as non-limiting examples, any known
form of dioxide or silicic acid, alkoxy- or other compounds of such
element. Useful sources of +5 valence element, e.g. phosphorus,
include, as non-limiting examples, any known form of phosphorus
acids or phosphorus oxides, phosphates and phosphites, and organic
derivatives of such element.
The organic solvent is a C.sub.5 -C.sub.10 alcohol or any other
liquid compound substantially immiscible with water, as nonlimiting
examples.
An organic directing agent can be selected from the group consisting
of organic mono- or dialkylamines, alkyl being of 3 or 4 carbon
atoms, and onium compounds having the following formula:
wherein R or R' is alkyl of from 1 to 20 carbon atoms, or combinations
thereof; M is a tetracoordinate element (e.g. nitrogen, phosphorus,
arsenic, antimony or bismuth); and X is an anion (e.g. fluoride,
chloride, bromide, iodide, hydroxide, acetate, sulfate, carboxylate,
etc.).
Particularly preferred directing agents for synthesis of the present
composition include onium compounds, above defined, wherein R is
alkyl of 1 to 4 carbon atoms, M is nitrogen and X is halide or hydroxide.
Non-limiting examples of these include tetrapropylammonium hydroxide,
tetrabutylammonium hydroxide, tetraethylammonium hydroxide and tetrapropylammonium
bromide; and dialkylamines wherein alkyl is propyl or butyl, also
tetrabutylammonium bromide, 2-hydroxyethyl derivatives of morpholine,
piperidine, and piperazine. Particularly preferred are n-dipropylamine,
tetra(2-hydroxyethyl)ammonium hydroxide and tetrabutylammonium hydroxide.
The composition prepared by the instant invention can be shaped
into a wide variety of particle sizes. Generally speaking, the particles
can be in the form of a powder, a granule, or a molded product,
such as an extrudate having 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, the
crystals can be extruded before drying or partially dried and then
extruded.
It may be desired to incorporate the new composition with another
material, i.e. a matrix, resistant to the temperatures and other
conditions employed in various organic conversion processes. Such
materials include active and inactive material and synthetic or
naturally occurring zeolites as well as inorganic materials such
as clays, silica and/or metal oxides, e.g. alumina. The latter may
be either naturally occurring or in the form of gelatinous precipitates
or gels including mixtures of silica and metal oxides. Catalyst
compositions containing the present composition will generally comprise
from about 1% to 90% by weight of the present composition and from
about 10% to 99% by weight of the matrix material. More preferably,
such catalyst compositions will comprise from about 2% to 80% by
weight of the present composition and from about 20% to 98% by weight
of the matrix.
Use of a material in conjunction with the new composition, i.e.
combined therewith, which is active, tends to alter the conversion
and/or selectivity of the overall catalyst in certain organic conversion
processes. Inactive materials suitably serve as diluents to control
the amount of conversion in a given process so that products can
be obtained economically and orderly without employing other means
for controlling the rate of reaction. These materials may be incorporated
into naturally occurring clays, e.g. bentonite and kaolin, to improve
the crush strength of the catalyst under commercial operating conditions.
Said materials, i.e. clays, oxides, etc., function as binders for
the catalyst. It may be desirable to provide a catalyst having good
crush strength because in commercial use it is desirable to prevent
the catalyst from breaking down into powder-like materials. These
clay binders have been employed normally only for the purpose of
improving the crush strength of the overall catalyst.
Naturally occurring clays which can be composited with the new
crystal include the montmorillonite and kaolin families which include
the subbentonites, and the kaolins commonly known as Dixie, McNamee,
Georgia and Florida clays or others in which the main mineral constituent
is halloysite, kaolinite, dickite, nacrite, or anauxite. Such clays
can be used in the raw state as originally mined or initially subjected
to calcination, acid treatment or chemical modification.
In addition to the foregoing materials, the present composition
can be composited with a porous matrix material such as aluminum
phosphate, silica-alumina, silica-magnesia, silica-zirconia, silica-thoria,
silica-beryllia, silica-titania as well as ternary compositions
such as silica-alumina-thoria, silica-alumina-zirconia, silica-alumina-magnesia
and silica-magnesia-zirconia. The relative proportions of finely
divided crystalline material and inorganic oxide gel matrix vary
widely, with the crystal content ranging from about 1 to about 90
percent by weight and more usually, particularly when the composite
is prepared in the form of beads, in the range of about 2 to about
80 weight percent of the composite.
Employing a catalytically active form of the present composition
as a catalyst component, said catalyst possibly containing additional
hydrogenation components, reforming stocks can be reformed employing
a temperature of from about 370.degree. C. to about 540.degree.
C., a pressure of from about 100 psig to about 1000 psig (791 to
6996 kPa), preferably from about 200 psig to about 700 psig (1480
to 4928 kPa), a liquid hourly space velocity is from about 0.1 to
about 10 preferably from about 0.5 to about 4 and a hydrogen to
hydrocarbon mole ratio of from about 1 to about 20 preferably from
about 4 to about 12.
A catalyst comprising the present composition can also be used
for hydroisomerization of normal paraffins, when provided with a
hydrogenation component, e.g. platinum. Such hydroisomerization
is carried out at a temperature of from about 90.degree. C. to about
375.degree. C., preferably from about 145.degree. C. to about 290.degree.
C., with a liquid hourly space velocity of from about 0.01 to about
2 preferably from about 0.25 to about 0.50 and with a hydrogen
to hydrocarbon mole ratio of from about 1:1 to about 5:1. Additionally,
such a catalyst can be used for olefin or aromatic isomerization,
employing a temperature of from about 200.degree. C. to about 480.degree.
C.
Such a catalyst can also be used for reducing the pour point of
gas oils. This reaction is carried out at a liquid hourly space
velocity of from about 10 to about 30 and at a temperature of from
about 425.degree. C. to about 595.degree. C.
Other reactions which can be accomplished employing a catalyst
comprising the composition of this invention containing a metal,
e.g. platinum, include hydrogenation-dehydrogenation reactions and
desulfurization reactions, olefin polymerization (oligomerization)
and other organic compound conversions, such as the conversion of
alcohols (e.g. methanol) or ethers (e.g. dimethylether) to hydrocarbons,
and the alkylation of aromatics (e.g. benzene) in the presence of
an alkylating agent (e.g. ethylene).
Sorption capacities may be determined as follows:
A weighed sample of the calcined adsorbant is contacted with a
flowing stream of the equilibrium vapor of the adsorbate at 25.degree.
C., admixed with dry nitrogen. Adsorbates are water vapor and benzene,
n-hexane, 2-methylpentane, xylene or cyclohexane vapors. The sample
temperature is maintained at 25.degree. C. to 90.degree. C. for
adsorbates other than ortho-xylene which can be 120.degree. C. and
water for which it was 60.degree. C. The increase in weight is measured
gravimetrically and converted to the adsorption capacity of the
sample in weight percent of calcined adsorbant.
Alpha Value may also be determined. When Alpha Value is examined,
it is noted that the Alpha Value is an approximate indication of
the catalytic cracking activity of the catalyst compared to a standard
catalyst and it gives the relative rate constant (rate of normal
hexane conversion per volume of catalyst per unit time). It is based
on the activity of the highly active silica-alumina cracking catalyst
taken as an Alpha of 1 (Rate Constant=0.016 sec.sup.-1). The Alpha
Test is described in U.S. Pat. No. 3354078 in The Journal of
Catalysis, 6 pp. 522-529 (Aug. 1965), and in The Journal of Catalysis,
61 p. 395 (1980), each incorporated herein by reference as to that
description.
When ion-exchange capacity is examined, it is determined by titrating
with a solution of sulfamic acid the gaseous ammonia evolved during
the temperature programmed decomposition of the ammonium-form of
the present composition. The method is described in Thermochimica
Acta, Vol. III, pp. 113-124 1971 by G. T. Kerr and A. W. Chester,
incorporated herein by reference as to that description. |