CA1251434A - Crystalline molecular sieves and their synthesis - Google Patents
Crystalline molecular sieves and their synthesisInfo
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Abstract
CRYSTALLINE MOLECULAR SIEVES AND THEIR SYNTHESIS
ABSTRACT
A synthetic crystalline siliceous molecular sieve material has the structure of zeolite ZSM-5, zeolite ZSM-11 or zeolite ZSM-12 and contains aluminum and at least two elements selected from the group consisting of boron, gallium and iron in its anionic framework. The crystalline material has a composition on an anhydrous basis and in terms of moles of oxides per mole of silica expressed the the formula:
a R2/nO : b Fe2O3 : c B2O3 : d Ga2O3 : e A12O3 : SiO2 wherein R is at least one cation having the valence n, and a = (1.0?0.2)(bfc+d+e) b = 0 to 0.05 c = 0 to 0.05 d = 0 to 0.05 e = 0.00003 to 0.02 b+c+d+e = 0.005 to 0.05 b+c+d ? 0.00047 and wherein only one of b, c and d can be O.
When in the ammonium form, the crystalline material has a TPAD
(temperature programmed ammonia desorption) peak of from greater than 300°C to less than 390°C and a TPAD half-height width from greater than 135°C to less than 155°C.
ABSTRACT
A synthetic crystalline siliceous molecular sieve material has the structure of zeolite ZSM-5, zeolite ZSM-11 or zeolite ZSM-12 and contains aluminum and at least two elements selected from the group consisting of boron, gallium and iron in its anionic framework. The crystalline material has a composition on an anhydrous basis and in terms of moles of oxides per mole of silica expressed the the formula:
a R2/nO : b Fe2O3 : c B2O3 : d Ga2O3 : e A12O3 : SiO2 wherein R is at least one cation having the valence n, and a = (1.0?0.2)(bfc+d+e) b = 0 to 0.05 c = 0 to 0.05 d = 0 to 0.05 e = 0.00003 to 0.02 b+c+d+e = 0.005 to 0.05 b+c+d ? 0.00047 and wherein only one of b, c and d can be O.
When in the ammonium form, the crystalline material has a TPAD
(temperature programmed ammonia desorption) peak of from greater than 300°C to less than 390°C and a TPAD half-height width from greater than 135°C to less than 155°C.
Description
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CRYSTALLINE MOLECULAR SIEVES AND THEIR SYNT~IESIS
This invention relates to crys-talline molecular sieves and their synthesis.
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 diffraction3 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 si~e within a specific zeolitic material. Since the dimensions of these pores are such as to accepk 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 posi-tive ion-containing crystalline aluminnsilicates. These aluminosilicates can be described as rigid three-dirnensional frameworks of SiO4 and Al04 in ~Ihich the tetrahedra are cross-linked by the sharing of oxygen atoms whereby the ratio of the total aluminum and silicon atoms to oxygen atoms is 1:2. The electrovalence of the tetrahedra containing aluminum 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 aluminum to the number of various cations, such as Cat2, 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 aluminosilicate by suitable selection of the cation.
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.
Prior art techniques have resulted in the formation of a great variety of synthetic aluminosilicate zeolites. The zeolites have come to be designated by letter or other convenient symbols, as illustrated by zeolite A (U. S. Patent 2,882,243~, zeolite X (U. S.
Patent 2,882,244), zeolite Y (U. S. Patent 3,130,007), zeolite ZK-5 (U. S. Patent 3,247,195), zeolite ZK-4 (U. S. Patent 3,314,752), zeolite ZSM-5 (U. S. Patent 3,702,886), zeolite ZSM-ll (U. S. Patent 3,709,979), zeolite ZSM-12 (U. S. Patent 3,832,449), zeolite ZSM-20 (U. S. Patent 3,972,983), zeolite ZSM-35 (U. S. Patent 4,016,245), zeolite ZSM-38 (U. S. Patent 4,046,859), and zeolite ZSM-23 (U. S. Patent 4,076,842).
A crystalline boron-containing silicate having the structure of zeolite ZSM-5 is known from U.S. Patent 4,269,813. In addition, U.S. Patent 3,328,119 teaches a synthetic crystalline aluminosilicate containing a minor amount of boria in i-ts crystal framework. Other U.S. patents relating to various metallosilicates include 3,329,480; 3,329,481 and 4,299,808. U.S. Patents 4,029,716 and 410787009 teach a crystalline aluminosilicate zeolite having a silica/alumina mole ratio of at least 12 and a Constraint Index within the range of 1 to 12 having combined therewith boron in an amount of at least 0.2 weight percent as a result of reaction of the zeolite with a boron-containing compoun~. U.S. Patent 4~331,641 teaches a method for preparing a crystalline boron-containing silicate having the structure of zeolite ZSM-5 from a reaction mixture containing less than 100 ppm aluminum.
A crystalline iron-containing silicate having the structure of zeolite ZSM-5 is known from U.S. Patent 4,208,305, whereas U.S.
Patent 4,238,318 discloses the use of the iron-containing silicate of U.S. Patent 4,208,305 as catalyst component for preparing aromatic hydrocarbons from a feedstock comprising acyclic organic compounds such as methanol. Crystalline iron-containing silicates are used in U.S. Patent 4,244,807 for reforming and in U.S. Patent 4,329,233 for purifying water.
( According to one aspect of present invention, there is provided a synthetic crystalline siliceous molecular sieve material having the structure of zeolite ZSM-5, zeolite ~SM-ll or zeolite ZSM-12 and containing aluminum and at least two elements selected from the group consisting of boron, gallium and iron in its anionic framework, said crystalline material having a composition on an anhydrous basis and in terms of moles of oxides per mole of silica expressed by the formula:
. a R2/nO : b Fe203 : c a20~ d Ga23 e A 2 3 2 wherein R is at least one cation having the valence n, and a - (1.0+~.2)(b+c+d+e) b = 0 to 0.~5 c = 0 to 0.05 d = 0 to 0.05 lS e = 0.00003 to 0.02 b+c+d~e - 0.005 to 0.05 b+c+d~ 0.00047 and wherein only one of b, c and d can be 0, and said crystalline material having, when in the ammonium form, a TPAD
(temperative-programmed ammonia desorption) peak of from greater than 300C to less than 390C and a TPAD half-height width fro,n greater than 135C to less than 155C.
According to a further aspect of the invention, there is provided a method for synthesizing a crystalline siliceous molecular sieve material having the structure of zeolite ZSM-5, zeolite ZSM-ll, or zeolite ZSM-12 and containing aluminum and at least two elements selected from the group consisting of boron, gallium and iron in its anionic framework which comprises preparing a mixture containing a source of organic cations, a source of silica, a source of alumina, a source of alkali or alkaline earth metal ions, water and sources of oxides of at least two metals selected from the group consisting of boron, gallium and iron, sald mixture having a composition, in terms of moles of oxides, ~ithin the following ranges:
, ., ~ !~
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F-3252 -~4~~
OH /SiO2 - 0.02 to 0.85 H20/OH = 10 to 800 SiO2/A1203 = 75 to 100,000 Q/(Q~M) = 0.05 to 0.90 when boron source present, SiO2/B203 = 4 to 600 when gallium source present, SiO2/Ga203 = 25 to 2,500 when iron source present, SiO2/Fe203 = 25 to 2,500 wherein Q represents organic cations and M represents alkali or alkaline earth rnetal lons, maintaining said mixture until said crystalline material is formed at a temperature of from 80C to 200C for a time of from 40 hours to 30 days, and recovering said crystalline material having a composition on an anhydrous basis and in terms of moles of oxides per mole of silica expressed by the formula:
a R2/n b Fe203 : c ~23 : d Ga203: e A1203 : SiO2 wherein R is at least one cation having the valence n and a = (1.0+0.2)(b+c+d+e) b = O to 0.05 c = O to 0.05 d = O to 0.05 e = 0.00003 to 0.02 b+c+d+e = 0.0005 to 0~05 b+c~d~ 0~00047 and wherein only one of b, c and d can be t F-3252 ~~5 and said crystalline material havin~, when in the ammonium form, a TPAD (temperature-programmed ammonia desorption) peak of from greater than 300C to less than 390C and a TPAD half-height width of from greater than 135C to less than 155C.
The crystalline metallosilicate of this invention is a unique composition of matter which exhibits a va:Luable combination of catalytic and hydrophilic properties which distinguishes it from aluminosilicatesS boron-containing silicates, gallium-containing silicates and iron-containing silicates of any known structure.
It is known that catalytic activity and hydrophilic properties of aluminosilicates decrease with increased silica/alumina mole ratios. It is also known that certain aluminosilicates, e.g. mordenite5 beta and ZSM-35, become more difficult to synthesize as the mole ratio of silica/alumina in the crystallization mixture is increased. It is noted that boron-containing silicates (M. Taramasso et al, Proceedings of the Fifth Internatlonal Confarence on Zeolites, Heyden & Son Ltd., 1980, pp. 40-4~) having the structure of zeolites ZSM-5, ZSM-ll and ~eta can be prepared, but, like the corresponding aluminosilicate, the hydrophilic properties thereof may be decreased by increasing the silica/boria mole ratio.
The metallosilicate molecular sieve material of this invention, however, overcomes the potential problems associated with high silica/alumina mole ratio aluminosilicates and with borosilicates and ferrosilicates in that the present material exhibits a controlled acid strength and hydrophilic proper-ties distinguishing it from known aluminosilicates, borosilicates, gallosilicates and ferrosilicates.
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In this respect, it is important not to confuse the concentration of acid sites with the acid strength of a site. The present invention enables the acid strength of a synthetic crystalline molecular sieve material to be tailored or controlled in its synthesis. Acid activity measured by Alpha Value, hereinafter more particularly defined, can be altered downward by (1) steaming a higher Alpha zeolite, by (2~ crystallization of the zeolite with a higher SiO2/A1203 mole ratio or by (3) crystallization of the zeolite as a metalloaluminosilicate, the metal other than aluminum taking the place of aluminum in the zeolite structure. Method (3) may provide a product zeolite having the same number of acid sites as the product zeolite of method (1), but their acid strength is lower Alpha Value correlates with the number of acid sites only when the acid strength of those sites is constant and su~fic:lently high to catalyze the cracking o~ n-hexane. It is believed that contralling acid-strength by the present invention will provide a more selective catalyst than is obtainable by steaming a higher Alpha Value 7eolite.
It is noted that the difference in zeolite acid site density is equivalent to the concentration of an aqueous acid solution, e.g. a solution of H2S04, which can be titrated. The difference in acid strength is equivalent to difference in pK values of aqueous acids, e.g. t'strong" acids such as H250~, HN03 and HCl, "medium strong" acids such as H3P0~, and "weak" acids such as H3803, H2C03 and H4SiO4, which can be measured by the pH at which -these acids are neutralized (titration curve), or, conversely, by the temperature at which the acid releases a volatile base, e.g. NH3, indicating the strength with which the acid holds the base, e.g. as NH4 ~.
While not wishing to be bound by any particular theory of operation, it has been noted that depending on the ratio of Si/Al in the crystal framework of a zeolite, the influence of Si-0 on -the Al 0 bond leng~h may be larger or smaller. A shortening of the Al-0 ! bond, as happens as the SiO2/A1203 ratio increases, results in :~S~ 3~
a stronger acid, but the number of acid sites (H~-ion concentration) decreases. In a framework aluminosilicate, such as a zeolite ZSM-ll synthesized as in U.S. Patent 3,709,979, the acid strength of the proton associated with an A104 tetrahedron correlates with the Al-0 bond length The longer the bond~ the weaker is the acid; the shorter the bond, the stronger is the acid.
Since there is a certain narrow range of Al-0 bond lengths within a structure, there is a corresponding range of acid strengths.
Information on the relative acid strengths can be obtained by following the desorption of ammonia from an ammonium zeolite upon heating with a constant heating rate, e.g. 10C/minute. The desorbed ammonia is continually purged from the thermogravimetric unit with helium and absorbed from a gas stream in boric acid/NH4Cl, where it is continuously titrated with sulfamic acid using an automated titrator (G.T. Kerr and A.W. Chester, Ther o Acta., 19717 3, 113). The rate at which the titrant is added ls recorded as a furlction of the sample temperature. The temperature at which the rate of ammonia evolution reaches a maximum, the temperature-programmed ammonia desorption (TPAD~ peak temperature, is a measure of the acid strength of the zeolite acid, since a weaker acid would release NH3 at a lower temperature, a stronger acid at a higher temperature.
~hereas an aluminosilicate ZSM-ll of SiO2/A12D3 molar ratio of 75 shows the TPAD peak at 380C, a zeolite of ZSM-ll structure having a SiO2/~A1203+Fe203) molar ratio of 68 and a Fe/(Fe+Al) atomio ratio of 0.92 gives a TPAD peak at 315C, and a zeolite of ZSM-ll structure having a SiO2/(A1203+Fe203) molar ratio of 73 and a Fe/(Fe+Al) atomic ratio of 0.5 gives a TPAD peak at 335C.
The widths of the TPAD peaks at half-height for various zeolite samples are measured and found to be 138C for the aluminosilicate ZSM-ll, 148C for the sample wi-th Fe/(Al+Fe) = 0.92 and 148C for the sample containing Fe and Al in the ratio of about 1:1, i.e. Fe/(Al~Fe) = 0.5.
f~
F-325~ 8 It is concluded from these results that the bond lengths of Fe-0, Ga-0 and Al-0 are modified by their influence in the crystal structure upon one another resulting in essentially one common acid strength intermediate to those of the pure Al-, pure Ga- and pure Fe-silicates.
Therefore, the TPAD peak with temperature and half-heigh-t width and the Alpha activity indicate that mixed metallosilicates have acid strength intermediate to ferrosilicate, gallosilicate or borosilicate and aluminosilicate, and the acid strength is modified by the mutual effect of the Al-0, Ga-0, B-0 and Fe-0 bonds on their length. This observation allows the conclusion that the acid sites of the presently synthesized acid strenthtailored zeolite do not behave like hyd~ogen sites on alurninosilicate (stronger) or like hydrogen sites on ferrosilicates, gallosilicates or borosilicates (weaker), but a new type of acid site is unexpectedly formed.
The physical structure of the metallosillcate of this invention cnntaining aluminum and two or three of boron, gallium and iron in tetrahedrally coordinated structural positions may be that zeolite ZSM,5, ZSM-ll or ZSM-12. U.S. Patents 3,702,886 and ~e.
29,948 describe ZSM-5 and its distinguishing X-ray diffraction pattern whereas corresponding disclosure of ZSM-ll and ZSM-12 is contained in U.S. Patent Nos. 3,709,979 and 3,832,449 respectively.
The acid-strength tailored metallosilicate of the present invention can be beneficially thermally treated, either before or after ion exchange. This thermal treatment is performed by heating the crystalline material in an atmosphere such as air1 nitrogen, hydrogen, steam, etc, at a temperature of from about 370~C to about 1100C 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. It may be desirable in certain instances to conduct this thermal treatment at rrom about 370C to about 750C~ but the structure of the acid-strength tailored material hereof should be stable up to about 1100C.
F-3252 ~~9~~
In general, the acid strength-tailored metallosilicate of the present invention can be prepared from a reaction mixture containing a source of cations, such as, for example, organic nitrogen-containing cations, an alkali or alkaline earth metal ion source, a source of silicon, such as, for example, a silicate, a source of aluminum, such as, for example, an aluminate and water.
Additionally, the reaction mixture will contain two or three sources of boron, gallium and iron, such as, for example an oxide of boron, e.g. a borate or boric acid, an iron salt and a gallium salt. The reaction mixture will have a composition, in terms of mole ratios of oxides, within the following ranges:
~road Preferred OH-/SiO2 0.02 to 0.85 0O04 to 0.65 H20/OH 10 to 800 2û to 600 SiO2/A1203 75 to lOO,OûO 150 to 50,000 Q/(Q+M) 0.05 to 0.90 0.05 to 0.80 when boron source present, SiO2/B203 4 to 600 ln to 200 when gallium source present, SiO2/Ga203 25 to 2,500 35 to 1,000 when iron source present, SiO2/Fe203 25 to 2,500 35 to 1,000 wherein Q represents organic cations and M represents alkali or all<aline earth metal ions.
Reaction conditions comprise heating the foregoing reaction mixture to a temperature of from 80C to 200C for a period of time of from 40 hours to 30 days. A more preferred temperature range is from 100C to 180C with the amount of time at a temperature in such range being from 60 hours to 15 days.
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The digestion of the gel particles is carried out untll crys-tals of the desired acid strengthtailored metallosilicate form. The crystalline product is recovered by separating same from the reaction medium, as by cooling the whole to room temperature, filtering and washing at conditions including a pH above 7.
The above reaction mixture composition can be prepared utilizing materials which supply the appropriate oxides. Such compositions may include sodium silicate, silica hydrosol, silica gel, silicic acid, sodium hydroxide, a source of aluminum, a source of boron, a source of gallium, a source of iron and an appropriate organic compound. The source of aluminum may be an added aluminum-containing compound or silica-containing materials or alkali metal containing materials containing aluminum. The source of iron rnay be an iron salt such as, for example, ferric sulfate.
The source of gallium may be a gallium salt such as, for ex~mple, gallium chloride. The organic compounds act as directing agents and contain an element of Group V~, such as nitrogen or phosphorus.
Primary organic amines containing from 2 to 10 carbon atoms or organic ammonium compounds such as tetraalkylammonium compounds in which the alkyl contains from 2 to 5 carbon atoms will direct the formation of metallosilicate having the structure of zeolite ZSM-5 from the above reaction mixture under appropriate conditions. The quaternary compounds of tetrabutylammonium chloride or hydroxide may be used to direct synthesis under appropriate conditions of metallosilicate having the structure of ZSM-ll. One or more alkylenediamines having from 7 to 12 carbon atoms (see U.S. Patent 4,108,881), may be also used to direct synthesis of a metallosilicate having the structure of ZSM-ll. Tetraethylammonium cation sources may be used to direct synthesis of metallosilicate having the structure of ZSM-12 under appropriate conditions.
In particular, when metallosilicate having the structure of zeolite ZSM-5 is desired, the reaction mixture will have a composition, in terms of mole ratios of oxides, within the following ranges:
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Broad _referred OH-/SiO2 0.02 to 0.70 0.04 to 0.60 H20/OH- 10 to 400 20 to 300 sio2/A123 100 to 100,000 200 to 50,000 ~/(Q~M) 0.05 to 0.90 0.05 to 0.80 when boron source provided, SiO2/B203 4 to 300 20 to 200 when galliurn source provided, sio2/Ga23 25 to 2,500 35 to 1,000 when iron source provided, SiO~/Fe203 25 to 2,500 35 to 1,000 wherein Q and M are as above defined and wherein at least two of the boron,gallium and iron sources are present. Reaction conditions will include a temperature of from 80C to about 200C, preferably from 100C to 1~0C, for a time o~ From ~0 hours to 30 days, preferably from about 60 hours to 15 days.
When metallosilicate having the structure of zeolite ZSM-ll is desired, the reaction mixture will have a composition, in terms of mole ratios of oxides, within the following ranges:
aroad Preferred _ OH-/SiO2 0.02 to 0.80 0.04 to 0.50 H20/OH 25 to 800 50 to 600 SiO2/A1203 100 to 100,000 200 to 50,0ûO
Q/(Q~M) 0.05 to 0.80 0.05 to 0.70 when boron source provided, SiO2/B203 4 to 300 20 to 200 3~
when gallium source provided, SiO2~Ga203 25 to 2,500 35 to 1,000 when iron source provided, SiO2/Fe203 25 to 2,500 35 to l,ooo wherein Q and M are as above defined and at least two of the boron, gallium and iron sources are present. Crystallization temperatures will be from 80C to 160C, preferably from 100C to 140C, and times are from 40 hours to 30 days, preferably from 60 hours to 15 days.
~hen metallosilicate having the structure of zeolite ZSM-12 is desired, the reaction mixture will have a composition, in terms of mole ratios of oxides, within the following ranges:
Broad Preferrecl OH-/SiO2 0.10 to 0.85 0.15 to 0.65 H20/OH 20 to 300 30 to 200 SiO2/A1203 75 to 100,000 150 to 6,000 Q/(Q-I~) 0.20 to 0.90 0.30 to 0.7 when boron source provided, SiO2/B203 5 to 600 10 to 200 when galliurn source provided, SiO2/Ga203 30 to 2,500 50 to 1,000 when iron source provided, SiO2/Fe203 30 to 2,500 50 to 1,000 wherein Q and M are as above defined, and at least two of the boron, gallium and iron sources are present. Crystallization temperatures are from 100C to 180C, preferably from 120C to 160C, for times of from ~0 hours to ~ days, preferably for 60 hours to about 15 days.
Another way to direct synthesis of the present metallosilicate molecular sieve having a particular crystal structure is to provide seed crystals of the desired structure, e.g.
metallosilicate zeolite of ZSM-5 structure, in the reaction mixture initially. This may be facilitated by providing at least about 0.01 percent, preferably at least about 0.1 percent and still more preferably at least about l percent seed crystals of the desired metallosilicate (based on total reaction mixture weight).
The metallosilicate crystals 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 partlc:le 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.
The original alkali or alkaline earth metal cations of the as synthesized acid metallosilicate of the invention 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. Preferred metal cations include rare earth metal and metals of ~roups IA, IIA, IIIA, IVA, Ia~
IIIB, IVB and VIII of the Periodic Table of the Elements.
Typical ion exchange technique would be to contact -the synthetic ferroaluminosilicate with a salt of the desired replacing cation or cations. Examples of such salts include the halides, e.g. chlorides, nitrates and sulfates.
It may be desired to incorporate the ne~ metallosilicate crystal with another material resistant to the temperatures and other conditions employed in various organic conversion processes.
, F-32s2 --14--Such materials include active and inactive materials 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.
Use of a material in conjunction with the new ferroaluminosilicate crystal, i.e. cornbined 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 condltions. 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 ls 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. Binders useful for compositing with the present crystal also include inorganic oxides, notably alumina.
In addition to the foregoing materials, the crystalline metallosilicate can be composited with a porous rnatrix material such as silica-alumina, silica-magnesia9 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 oxlde gel matrix vary widely, with the crystal content ranging from 1 to 90 percent by weight and more usually, part:icularly when the composite is prepared in the form of beads, in the range of 2 to 80 weight percent of the composite.
Employing a catalytically active form of the metallosilicate material of this invention as a catalyst component, said catalyst possibly containing additional hydrogenation components, reforming stocks can be reformed employing a temperature of from 370C to 540C, a pressure of from 791 to 6996 kPa (100 to 1000 psig), preferably from i480 to 4928 kPa (200 to 700 psig), a liquid hourly space velocity of from 0.1 to 10, preferably from 0.5 to 4, and a hydrogen to hydro~arbon mole ratio of From 1 to 20, preferably from ~ to 12.
A catalyst comprising the present metallosilicate rnolecular sieve 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 90C to 375C, preferably from 145C to 290C, with a liquid hourly space velocity of from 0.01 to 2, preferably from 0.25 to 0.50, and with a hydrogen to hydrocarbon mole ratio of from 1:1 to 5:1.
Additionally, such a catalyst can be used for olefin or aromatic isomerization, employing a temperature of from abo~lt 200C to about ~80C.
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 425C to about 595C.
Other reactions which can be accomplished employing a catalyst comprising -the metallosilicate 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).
In order to more fully illustrate the nature of-the invention and the manner of practicing same, the following examples are presented. In the examples, whenever adsorption data are set forth for comparison of sorptive capacities for water, cyclohexane and n-hexane, they were determined ac follows:
A weighed sample of the calcined adsorbant was contacted with the desired pure adsorbate vapor in an adsorption chamber, evacuated to 1 mm and contacted with 12 mm Hg of water vapor or 20 mm Hg of n-hexane, or cyclohexane vapor, pressures less than the vapor-liquid equilibrium pressure of the respective adsorbate at room temperature. The pressure was kept constant (withln about 0.5 mm) by addition of adsorbate vapor controlled by a manostat during the adsorption period, which did not exceed about 8 hours.
As adsorbate was adsorbed by the new metallosilicate material, the decrease in pressure caused the manostat to open a valve which admitted more adsorbate vapor to the chamber to restore the above control pressures. Sorption was complete when the pressure change was not sufficlent to activate the manostat. The lncrease in weight was calculated as the adsorption capaclty of the sample in 9/lOO 9 of calcined adsorbant.
ample 1 Ferric sulfate, Fe2(504)3 7.1H20, 1.85 grams, was dissolved in 46.6 grams of water. Ten grams of concentrated sulfuric acid was added with stirring, followed by a solution of 0.5 gram of boric acid in 35.1 grams of a 29.8/o solution of tetrapropylammonium bromide. Sodium sulfate, Na2S04, 6.5 grams, was added and dissolved. Finally a mixture of 120.0 grams of sodium silicate (8.9~ Na20, 28.7% SiO2, 200 ppm Al), 69.4 grams of water and 0.3 gram of Daxad 27 (a sodium salt of polymerized substituted benzoid alkyl sulfonic acid combined with an inert inorganic suspending agent~ was added with vigorous stirring. The reaction mixture, which had a composition in mole ratios as follows:
OH /SiO2 = 0.22 SiO2/A1203 = 2440 SiO2~Fe203 = 164 SiO2/a203 = 143 TPAi(TPA~Na) = O.20 was then heated at 100C for crystallization. The reaction was terminated after 28 days. The product had the X-ray diffraction pattern of ZS~-5 and the crystallinity was 75% compared with an iron- and boron-free reference sample prepared as in U.S. Patent 3,702,88~
The chemical composition of the product metallosilicate was, in wt. %:
Si2 82.8 A1203 0.23 ~23 0.29 Fe203 1.43 Na20 1.48 N 0.70 Ash 85.4 SiO2/(A1~03+Fe203+B203), molar 89.85 B23/(A123~Fe23+823), molar 0.271 Fe203/(A1203+ e2 3 ~ 3)' 0.582 A123/(A123+Fe23+823), molar 0.147 The sorption capacities of the solid product calcined at 538C for 3 hours in air, in 9/1009, were:
Cyclohexane, 20 Torr 6.8 n-Hexane, 20 Torr 10.2 Water, 12 Torr 4.5 * Trade m~k !~1 1~
3~
~xample 2 The reaction mixture for this example was similar to that of Example 1, except that 3.7 grams of Fe2(S04)3 7.1H20, 8.0 grams of concentrated sulf`uric acid and 1.0 grams of boric acid 5 were used. It had a composition in mole ratios as follows:
OH /SiO2 = 0.25 H20/OH = 87 SiO2/A1203 = 2440 SiO2/Fe203 = 82 SiO2/B203 = 71 TPA/(TPA+Na) = 0.20 The product obtained after heating the reaction mixture at 100C for 40 days had the X-ray di~fraction pattern of` ZSM-5 and crystallinity was 65% compared with the boron- and iron-f`ree reference sample.
The chemical composition of` the product metallosilicate, in wt %, was:
SiO2 82.3 A1203 0.26 23 0.13
CRYSTALLINE MOLECULAR SIEVES AND THEIR SYNT~IESIS
This invention relates to crys-talline molecular sieves and their synthesis.
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 diffraction3 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 si~e within a specific zeolitic material. Since the dimensions of these pores are such as to accepk 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 posi-tive ion-containing crystalline aluminnsilicates. These aluminosilicates can be described as rigid three-dirnensional frameworks of SiO4 and Al04 in ~Ihich the tetrahedra are cross-linked by the sharing of oxygen atoms whereby the ratio of the total aluminum and silicon atoms to oxygen atoms is 1:2. The electrovalence of the tetrahedra containing aluminum 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 aluminum to the number of various cations, such as Cat2, 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 aluminosilicate by suitable selection of the cation.
~g 3~
.
Prior art techniques have resulted in the formation of a great variety of synthetic aluminosilicate zeolites. The zeolites have come to be designated by letter or other convenient symbols, as illustrated by zeolite A (U. S. Patent 2,882,243~, zeolite X (U. S.
Patent 2,882,244), zeolite Y (U. S. Patent 3,130,007), zeolite ZK-5 (U. S. Patent 3,247,195), zeolite ZK-4 (U. S. Patent 3,314,752), zeolite ZSM-5 (U. S. Patent 3,702,886), zeolite ZSM-ll (U. S. Patent 3,709,979), zeolite ZSM-12 (U. S. Patent 3,832,449), zeolite ZSM-20 (U. S. Patent 3,972,983), zeolite ZSM-35 (U. S. Patent 4,016,245), zeolite ZSM-38 (U. S. Patent 4,046,859), and zeolite ZSM-23 (U. S. Patent 4,076,842).
A crystalline boron-containing silicate having the structure of zeolite ZSM-5 is known from U.S. Patent 4,269,813. In addition, U.S. Patent 3,328,119 teaches a synthetic crystalline aluminosilicate containing a minor amount of boria in i-ts crystal framework. Other U.S. patents relating to various metallosilicates include 3,329,480; 3,329,481 and 4,299,808. U.S. Patents 4,029,716 and 410787009 teach a crystalline aluminosilicate zeolite having a silica/alumina mole ratio of at least 12 and a Constraint Index within the range of 1 to 12 having combined therewith boron in an amount of at least 0.2 weight percent as a result of reaction of the zeolite with a boron-containing compoun~. U.S. Patent 4~331,641 teaches a method for preparing a crystalline boron-containing silicate having the structure of zeolite ZSM-5 from a reaction mixture containing less than 100 ppm aluminum.
A crystalline iron-containing silicate having the structure of zeolite ZSM-5 is known from U.S. Patent 4,208,305, whereas U.S.
Patent 4,238,318 discloses the use of the iron-containing silicate of U.S. Patent 4,208,305 as catalyst component for preparing aromatic hydrocarbons from a feedstock comprising acyclic organic compounds such as methanol. Crystalline iron-containing silicates are used in U.S. Patent 4,244,807 for reforming and in U.S. Patent 4,329,233 for purifying water.
( According to one aspect of present invention, there is provided a synthetic crystalline siliceous molecular sieve material having the structure of zeolite ZSM-5, zeolite ~SM-ll or zeolite ZSM-12 and containing aluminum and at least two elements selected from the group consisting of boron, gallium and iron in its anionic framework, said crystalline material having a composition on an anhydrous basis and in terms of moles of oxides per mole of silica expressed by the formula:
. a R2/nO : b Fe203 : c a20~ d Ga23 e A 2 3 2 wherein R is at least one cation having the valence n, and a - (1.0+~.2)(b+c+d+e) b = 0 to 0.~5 c = 0 to 0.05 d = 0 to 0.05 lS e = 0.00003 to 0.02 b+c+d~e - 0.005 to 0.05 b+c+d~ 0.00047 and wherein only one of b, c and d can be 0, and said crystalline material having, when in the ammonium form, a TPAD
(temperative-programmed ammonia desorption) peak of from greater than 300C to less than 390C and a TPAD half-height width fro,n greater than 135C to less than 155C.
According to a further aspect of the invention, there is provided a method for synthesizing a crystalline siliceous molecular sieve material having the structure of zeolite ZSM-5, zeolite ZSM-ll, or zeolite ZSM-12 and containing aluminum and at least two elements selected from the group consisting of boron, gallium and iron in its anionic framework which comprises preparing a mixture containing a source of organic cations, a source of silica, a source of alumina, a source of alkali or alkaline earth metal ions, water and sources of oxides of at least two metals selected from the group consisting of boron, gallium and iron, sald mixture having a composition, in terms of moles of oxides, ~ithin the following ranges:
, ., ~ !~
.3~
F-3252 -~4~~
OH /SiO2 - 0.02 to 0.85 H20/OH = 10 to 800 SiO2/A1203 = 75 to 100,000 Q/(Q~M) = 0.05 to 0.90 when boron source present, SiO2/B203 = 4 to 600 when gallium source present, SiO2/Ga203 = 25 to 2,500 when iron source present, SiO2/Fe203 = 25 to 2,500 wherein Q represents organic cations and M represents alkali or alkaline earth rnetal lons, maintaining said mixture until said crystalline material is formed at a temperature of from 80C to 200C for a time of from 40 hours to 30 days, and recovering said crystalline material having a composition on an anhydrous basis and in terms of moles of oxides per mole of silica expressed by the formula:
a R2/n b Fe203 : c ~23 : d Ga203: e A1203 : SiO2 wherein R is at least one cation having the valence n and a = (1.0+0.2)(b+c+d+e) b = O to 0.05 c = O to 0.05 d = O to 0.05 e = 0.00003 to 0.02 b+c+d+e = 0.0005 to 0~05 b+c~d~ 0~00047 and wherein only one of b, c and d can be t F-3252 ~~5 and said crystalline material havin~, when in the ammonium form, a TPAD (temperature-programmed ammonia desorption) peak of from greater than 300C to less than 390C and a TPAD half-height width of from greater than 135C to less than 155C.
The crystalline metallosilicate of this invention is a unique composition of matter which exhibits a va:Luable combination of catalytic and hydrophilic properties which distinguishes it from aluminosilicatesS boron-containing silicates, gallium-containing silicates and iron-containing silicates of any known structure.
It is known that catalytic activity and hydrophilic properties of aluminosilicates decrease with increased silica/alumina mole ratios. It is also known that certain aluminosilicates, e.g. mordenite5 beta and ZSM-35, become more difficult to synthesize as the mole ratio of silica/alumina in the crystallization mixture is increased. It is noted that boron-containing silicates (M. Taramasso et al, Proceedings of the Fifth Internatlonal Confarence on Zeolites, Heyden & Son Ltd., 1980, pp. 40-4~) having the structure of zeolites ZSM-5, ZSM-ll and ~eta can be prepared, but, like the corresponding aluminosilicate, the hydrophilic properties thereof may be decreased by increasing the silica/boria mole ratio.
The metallosilicate molecular sieve material of this invention, however, overcomes the potential problems associated with high silica/alumina mole ratio aluminosilicates and with borosilicates and ferrosilicates in that the present material exhibits a controlled acid strength and hydrophilic proper-ties distinguishing it from known aluminosilicates, borosilicates, gallosilicates and ferrosilicates.
3~
In this respect, it is important not to confuse the concentration of acid sites with the acid strength of a site. The present invention enables the acid strength of a synthetic crystalline molecular sieve material to be tailored or controlled in its synthesis. Acid activity measured by Alpha Value, hereinafter more particularly defined, can be altered downward by (1) steaming a higher Alpha zeolite, by (2~ crystallization of the zeolite with a higher SiO2/A1203 mole ratio or by (3) crystallization of the zeolite as a metalloaluminosilicate, the metal other than aluminum taking the place of aluminum in the zeolite structure. Method (3) may provide a product zeolite having the same number of acid sites as the product zeolite of method (1), but their acid strength is lower Alpha Value correlates with the number of acid sites only when the acid strength of those sites is constant and su~fic:lently high to catalyze the cracking o~ n-hexane. It is believed that contralling acid-strength by the present invention will provide a more selective catalyst than is obtainable by steaming a higher Alpha Value 7eolite.
It is noted that the difference in zeolite acid site density is equivalent to the concentration of an aqueous acid solution, e.g. a solution of H2S04, which can be titrated. The difference in acid strength is equivalent to difference in pK values of aqueous acids, e.g. t'strong" acids such as H250~, HN03 and HCl, "medium strong" acids such as H3P0~, and "weak" acids such as H3803, H2C03 and H4SiO4, which can be measured by the pH at which -these acids are neutralized (titration curve), or, conversely, by the temperature at which the acid releases a volatile base, e.g. NH3, indicating the strength with which the acid holds the base, e.g. as NH4 ~.
While not wishing to be bound by any particular theory of operation, it has been noted that depending on the ratio of Si/Al in the crystal framework of a zeolite, the influence of Si-0 on -the Al 0 bond leng~h may be larger or smaller. A shortening of the Al-0 ! bond, as happens as the SiO2/A1203 ratio increases, results in :~S~ 3~
a stronger acid, but the number of acid sites (H~-ion concentration) decreases. In a framework aluminosilicate, such as a zeolite ZSM-ll synthesized as in U.S. Patent 3,709,979, the acid strength of the proton associated with an A104 tetrahedron correlates with the Al-0 bond length The longer the bond~ the weaker is the acid; the shorter the bond, the stronger is the acid.
Since there is a certain narrow range of Al-0 bond lengths within a structure, there is a corresponding range of acid strengths.
Information on the relative acid strengths can be obtained by following the desorption of ammonia from an ammonium zeolite upon heating with a constant heating rate, e.g. 10C/minute. The desorbed ammonia is continually purged from the thermogravimetric unit with helium and absorbed from a gas stream in boric acid/NH4Cl, where it is continuously titrated with sulfamic acid using an automated titrator (G.T. Kerr and A.W. Chester, Ther o Acta., 19717 3, 113). The rate at which the titrant is added ls recorded as a furlction of the sample temperature. The temperature at which the rate of ammonia evolution reaches a maximum, the temperature-programmed ammonia desorption (TPAD~ peak temperature, is a measure of the acid strength of the zeolite acid, since a weaker acid would release NH3 at a lower temperature, a stronger acid at a higher temperature.
~hereas an aluminosilicate ZSM-ll of SiO2/A12D3 molar ratio of 75 shows the TPAD peak at 380C, a zeolite of ZSM-ll structure having a SiO2/~A1203+Fe203) molar ratio of 68 and a Fe/(Fe+Al) atomio ratio of 0.92 gives a TPAD peak at 315C, and a zeolite of ZSM-ll structure having a SiO2/(A1203+Fe203) molar ratio of 73 and a Fe/(Fe+Al) atomic ratio of 0.5 gives a TPAD peak at 335C.
The widths of the TPAD peaks at half-height for various zeolite samples are measured and found to be 138C for the aluminosilicate ZSM-ll, 148C for the sample wi-th Fe/(Al+Fe) = 0.92 and 148C for the sample containing Fe and Al in the ratio of about 1:1, i.e. Fe/(Al~Fe) = 0.5.
f~
F-325~ 8 It is concluded from these results that the bond lengths of Fe-0, Ga-0 and Al-0 are modified by their influence in the crystal structure upon one another resulting in essentially one common acid strength intermediate to those of the pure Al-, pure Ga- and pure Fe-silicates.
Therefore, the TPAD peak with temperature and half-heigh-t width and the Alpha activity indicate that mixed metallosilicates have acid strength intermediate to ferrosilicate, gallosilicate or borosilicate and aluminosilicate, and the acid strength is modified by the mutual effect of the Al-0, Ga-0, B-0 and Fe-0 bonds on their length. This observation allows the conclusion that the acid sites of the presently synthesized acid strenthtailored zeolite do not behave like hyd~ogen sites on alurninosilicate (stronger) or like hydrogen sites on ferrosilicates, gallosilicates or borosilicates (weaker), but a new type of acid site is unexpectedly formed.
The physical structure of the metallosillcate of this invention cnntaining aluminum and two or three of boron, gallium and iron in tetrahedrally coordinated structural positions may be that zeolite ZSM,5, ZSM-ll or ZSM-12. U.S. Patents 3,702,886 and ~e.
29,948 describe ZSM-5 and its distinguishing X-ray diffraction pattern whereas corresponding disclosure of ZSM-ll and ZSM-12 is contained in U.S. Patent Nos. 3,709,979 and 3,832,449 respectively.
The acid-strength tailored metallosilicate of the present invention can be beneficially thermally treated, either before or after ion exchange. This thermal treatment is performed by heating the crystalline material in an atmosphere such as air1 nitrogen, hydrogen, steam, etc, at a temperature of from about 370~C to about 1100C 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. It may be desirable in certain instances to conduct this thermal treatment at rrom about 370C to about 750C~ but the structure of the acid-strength tailored material hereof should be stable up to about 1100C.
F-3252 ~~9~~
In general, the acid strength-tailored metallosilicate of the present invention can be prepared from a reaction mixture containing a source of cations, such as, for example, organic nitrogen-containing cations, an alkali or alkaline earth metal ion source, a source of silicon, such as, for example, a silicate, a source of aluminum, such as, for example, an aluminate and water.
Additionally, the reaction mixture will contain two or three sources of boron, gallium and iron, such as, for example an oxide of boron, e.g. a borate or boric acid, an iron salt and a gallium salt. The reaction mixture will have a composition, in terms of mole ratios of oxides, within the following ranges:
~road Preferred OH-/SiO2 0.02 to 0.85 0O04 to 0.65 H20/OH 10 to 800 2û to 600 SiO2/A1203 75 to lOO,OûO 150 to 50,000 Q/(Q+M) 0.05 to 0.90 0.05 to 0.80 when boron source present, SiO2/B203 4 to 600 ln to 200 when gallium source present, SiO2/Ga203 25 to 2,500 35 to 1,000 when iron source present, SiO2/Fe203 25 to 2,500 35 to 1,000 wherein Q represents organic cations and M represents alkali or all<aline earth metal ions.
Reaction conditions comprise heating the foregoing reaction mixture to a temperature of from 80C to 200C for a period of time of from 40 hours to 30 days. A more preferred temperature range is from 100C to 180C with the amount of time at a temperature in such range being from 60 hours to 15 days.
3'~
The digestion of the gel particles is carried out untll crys-tals of the desired acid strengthtailored metallosilicate form. The crystalline product is recovered by separating same from the reaction medium, as by cooling the whole to room temperature, filtering and washing at conditions including a pH above 7.
The above reaction mixture composition can be prepared utilizing materials which supply the appropriate oxides. Such compositions may include sodium silicate, silica hydrosol, silica gel, silicic acid, sodium hydroxide, a source of aluminum, a source of boron, a source of gallium, a source of iron and an appropriate organic compound. The source of aluminum may be an added aluminum-containing compound or silica-containing materials or alkali metal containing materials containing aluminum. The source of iron rnay be an iron salt such as, for example, ferric sulfate.
The source of gallium may be a gallium salt such as, for ex~mple, gallium chloride. The organic compounds act as directing agents and contain an element of Group V~, such as nitrogen or phosphorus.
Primary organic amines containing from 2 to 10 carbon atoms or organic ammonium compounds such as tetraalkylammonium compounds in which the alkyl contains from 2 to 5 carbon atoms will direct the formation of metallosilicate having the structure of zeolite ZSM-5 from the above reaction mixture under appropriate conditions. The quaternary compounds of tetrabutylammonium chloride or hydroxide may be used to direct synthesis under appropriate conditions of metallosilicate having the structure of ZSM-ll. One or more alkylenediamines having from 7 to 12 carbon atoms (see U.S. Patent 4,108,881), may be also used to direct synthesis of a metallosilicate having the structure of ZSM-ll. Tetraethylammonium cation sources may be used to direct synthesis of metallosilicate having the structure of ZSM-12 under appropriate conditions.
In particular, when metallosilicate having the structure of zeolite ZSM-5 is desired, the reaction mixture will have a composition, in terms of mole ratios of oxides, within the following ranges:
~2.$~3'~
Broad _referred OH-/SiO2 0.02 to 0.70 0.04 to 0.60 H20/OH- 10 to 400 20 to 300 sio2/A123 100 to 100,000 200 to 50,000 ~/(Q~M) 0.05 to 0.90 0.05 to 0.80 when boron source provided, SiO2/B203 4 to 300 20 to 200 when galliurn source provided, sio2/Ga23 25 to 2,500 35 to 1,000 when iron source provided, SiO~/Fe203 25 to 2,500 35 to 1,000 wherein Q and M are as above defined and wherein at least two of the boron,gallium and iron sources are present. Reaction conditions will include a temperature of from 80C to about 200C, preferably from 100C to 1~0C, for a time o~ From ~0 hours to 30 days, preferably from about 60 hours to 15 days.
When metallosilicate having the structure of zeolite ZSM-ll is desired, the reaction mixture will have a composition, in terms of mole ratios of oxides, within the following ranges:
aroad Preferred _ OH-/SiO2 0.02 to 0.80 0.04 to 0.50 H20/OH 25 to 800 50 to 600 SiO2/A1203 100 to 100,000 200 to 50,0ûO
Q/(Q~M) 0.05 to 0.80 0.05 to 0.70 when boron source provided, SiO2/B203 4 to 300 20 to 200 3~
when gallium source provided, SiO2~Ga203 25 to 2,500 35 to 1,000 when iron source provided, SiO2/Fe203 25 to 2,500 35 to l,ooo wherein Q and M are as above defined and at least two of the boron, gallium and iron sources are present. Crystallization temperatures will be from 80C to 160C, preferably from 100C to 140C, and times are from 40 hours to 30 days, preferably from 60 hours to 15 days.
~hen metallosilicate having the structure of zeolite ZSM-12 is desired, the reaction mixture will have a composition, in terms of mole ratios of oxides, within the following ranges:
Broad Preferrecl OH-/SiO2 0.10 to 0.85 0.15 to 0.65 H20/OH 20 to 300 30 to 200 SiO2/A1203 75 to 100,000 150 to 6,000 Q/(Q-I~) 0.20 to 0.90 0.30 to 0.7 when boron source provided, SiO2/B203 5 to 600 10 to 200 when galliurn source provided, SiO2/Ga203 30 to 2,500 50 to 1,000 when iron source provided, SiO2/Fe203 30 to 2,500 50 to 1,000 wherein Q and M are as above defined, and at least two of the boron, gallium and iron sources are present. Crystallization temperatures are from 100C to 180C, preferably from 120C to 160C, for times of from ~0 hours to ~ days, preferably for 60 hours to about 15 days.
Another way to direct synthesis of the present metallosilicate molecular sieve having a particular crystal structure is to provide seed crystals of the desired structure, e.g.
metallosilicate zeolite of ZSM-5 structure, in the reaction mixture initially. This may be facilitated by providing at least about 0.01 percent, preferably at least about 0.1 percent and still more preferably at least about l percent seed crystals of the desired metallosilicate (based on total reaction mixture weight).
The metallosilicate crystals 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 partlc:le 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.
The original alkali or alkaline earth metal cations of the as synthesized acid metallosilicate of the invention 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. Preferred metal cations include rare earth metal and metals of ~roups IA, IIA, IIIA, IVA, Ia~
IIIB, IVB and VIII of the Periodic Table of the Elements.
Typical ion exchange technique would be to contact -the synthetic ferroaluminosilicate with a salt of the desired replacing cation or cations. Examples of such salts include the halides, e.g. chlorides, nitrates and sulfates.
It may be desired to incorporate the ne~ metallosilicate crystal with another material resistant to the temperatures and other conditions employed in various organic conversion processes.
, F-32s2 --14--Such materials include active and inactive materials 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.
Use of a material in conjunction with the new ferroaluminosilicate crystal, i.e. cornbined 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 condltions. 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 ls 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. Binders useful for compositing with the present crystal also include inorganic oxides, notably alumina.
In addition to the foregoing materials, the crystalline metallosilicate can be composited with a porous rnatrix material such as silica-alumina, silica-magnesia9 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 oxlde gel matrix vary widely, with the crystal content ranging from 1 to 90 percent by weight and more usually, part:icularly when the composite is prepared in the form of beads, in the range of 2 to 80 weight percent of the composite.
Employing a catalytically active form of the metallosilicate material of this invention as a catalyst component, said catalyst possibly containing additional hydrogenation components, reforming stocks can be reformed employing a temperature of from 370C to 540C, a pressure of from 791 to 6996 kPa (100 to 1000 psig), preferably from i480 to 4928 kPa (200 to 700 psig), a liquid hourly space velocity of from 0.1 to 10, preferably from 0.5 to 4, and a hydrogen to hydro~arbon mole ratio of From 1 to 20, preferably from ~ to 12.
A catalyst comprising the present metallosilicate rnolecular sieve 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 90C to 375C, preferably from 145C to 290C, with a liquid hourly space velocity of from 0.01 to 2, preferably from 0.25 to 0.50, and with a hydrogen to hydrocarbon mole ratio of from 1:1 to 5:1.
Additionally, such a catalyst can be used for olefin or aromatic isomerization, employing a temperature of from abo~lt 200C to about ~80C.
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 425C to about 595C.
Other reactions which can be accomplished employing a catalyst comprising -the metallosilicate 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).
In order to more fully illustrate the nature of-the invention and the manner of practicing same, the following examples are presented. In the examples, whenever adsorption data are set forth for comparison of sorptive capacities for water, cyclohexane and n-hexane, they were determined ac follows:
A weighed sample of the calcined adsorbant was contacted with the desired pure adsorbate vapor in an adsorption chamber, evacuated to 1 mm and contacted with 12 mm Hg of water vapor or 20 mm Hg of n-hexane, or cyclohexane vapor, pressures less than the vapor-liquid equilibrium pressure of the respective adsorbate at room temperature. The pressure was kept constant (withln about 0.5 mm) by addition of adsorbate vapor controlled by a manostat during the adsorption period, which did not exceed about 8 hours.
As adsorbate was adsorbed by the new metallosilicate material, the decrease in pressure caused the manostat to open a valve which admitted more adsorbate vapor to the chamber to restore the above control pressures. Sorption was complete when the pressure change was not sufficlent to activate the manostat. The lncrease in weight was calculated as the adsorption capaclty of the sample in 9/lOO 9 of calcined adsorbant.
ample 1 Ferric sulfate, Fe2(504)3 7.1H20, 1.85 grams, was dissolved in 46.6 grams of water. Ten grams of concentrated sulfuric acid was added with stirring, followed by a solution of 0.5 gram of boric acid in 35.1 grams of a 29.8/o solution of tetrapropylammonium bromide. Sodium sulfate, Na2S04, 6.5 grams, was added and dissolved. Finally a mixture of 120.0 grams of sodium silicate (8.9~ Na20, 28.7% SiO2, 200 ppm Al), 69.4 grams of water and 0.3 gram of Daxad 27 (a sodium salt of polymerized substituted benzoid alkyl sulfonic acid combined with an inert inorganic suspending agent~ was added with vigorous stirring. The reaction mixture, which had a composition in mole ratios as follows:
OH /SiO2 = 0.22 SiO2/A1203 = 2440 SiO2~Fe203 = 164 SiO2/a203 = 143 TPAi(TPA~Na) = O.20 was then heated at 100C for crystallization. The reaction was terminated after 28 days. The product had the X-ray diffraction pattern of ZS~-5 and the crystallinity was 75% compared with an iron- and boron-free reference sample prepared as in U.S. Patent 3,702,88~
The chemical composition of the product metallosilicate was, in wt. %:
Si2 82.8 A1203 0.23 ~23 0.29 Fe203 1.43 Na20 1.48 N 0.70 Ash 85.4 SiO2/(A1~03+Fe203+B203), molar 89.85 B23/(A123~Fe23+823), molar 0.271 Fe203/(A1203+ e2 3 ~ 3)' 0.582 A123/(A123+Fe23+823), molar 0.147 The sorption capacities of the solid product calcined at 538C for 3 hours in air, in 9/1009, were:
Cyclohexane, 20 Torr 6.8 n-Hexane, 20 Torr 10.2 Water, 12 Torr 4.5 * Trade m~k !~1 1~
3~
~xample 2 The reaction mixture for this example was similar to that of Example 1, except that 3.7 grams of Fe2(S04)3 7.1H20, 8.0 grams of concentrated sulf`uric acid and 1.0 grams of boric acid 5 were used. It had a composition in mole ratios as follows:
OH /SiO2 = 0.25 H20/OH = 87 SiO2/A1203 = 2440 SiO2/Fe203 = 82 SiO2/B203 = 71 TPA/(TPA+Na) = 0.20 The product obtained after heating the reaction mixture at 100C for 40 days had the X-ray di~fraction pattern of` ZSM-5 and crystallinity was 65% compared with the boron- and iron-f`ree reference sample.
The chemical composition of` the product metallosilicate, in wt %, was:
SiO2 82.3 A1203 0.26 23 0.13
2 3 3.0 Na20 1.42 N 0.63 Ash 86.0 SiO2/(A1203+Fe203+B203), molar 59.2 23/(A123+Fe2o3+B23), molar 0.081 2U3/(A1203+Fe203+B2o3)~ molar 0.809 2o3/(A12o3+Fe2o3+92o3)~ molar 0.110 The sorption capacities o~ the calcined (538C, 3 hours, air) solid product, in 9/1009, were:
30Cyclohexane, 20 Torr 6.3 n-Hexane, 20 Torr 9.1 Water, 12 Torr 5.8 ~2~3~
Example 3 A 1.85 gram quantity of ferric sulfate, Fe2(S04)3 7.1 H20, was dissolved in 46.6 grams of water.
Ten grams of concentrated sulfuric acid was added with stirring, followed by a solution of 0.5 gram o~ boric acid in 35.1 grams of a 29.8% solution of tetrapropylammonium bromide. Sodium sulfate, Na2S04, 6.5 grams, was added and dissolved. Finally, a mixture of 120.0 grams of sodium silicate (8.9% Na20, 28.7% SiO2, 200 ppm Al), 69.4 grams of water and 0.3 grams of the dispersant Daxad 27 was added with vigorous stirring. The reaction mixture, identical in molar composition to that of Example 1, was then heated at 160C For crystallization. Crystallization was complete after 316 hours.
The product had the X-ray di~fraction pat~ern of ZSM-5 and crystallinity was 90% compared with the re~erence sample contaIning no boron or iron.
The chemical composition of the product metallosilicate, in weight %, was:
SiO2 85.2 A1203 0.24 ~23 0.52 Fe203 1.71 Na20 0.47 N 1.01 Ash 88.2 SiO2/(Al+S+Fe)203, molar 69.2 B203/(Al+8+Fe)203, molar 0.431 Fe203/(Al+B+Fe)203, molar 0.432 A1203/(Al+B+Fe)203, molar 0.137 The sorption capacities o~ the product solid, calcined at 538C in air for 3 hours, in 9/lOO9, were:
Cyclohexane, 20 Torr 7.0 n-Hexane, 20 Torr 10.3 Water, 12 Torr 7.0 Example 4 A 3.7 gram quantity of ferric sulfate, Fe2(S04)3 7.1 H20, was dissolved in 46.6 grams of water.
Eight grams of concentrated sulfuric acid was added with stirring, followed by a solution of 1 gram of boric acid in 35.1 grams of a 29.8% solution of tetrapropylammoniurn bromide. Sodium sulfate, Na2504, 6.5 grams was added and dissolved. Finally, a mixture of 120.0 grams of sodium silicate (8.9% Na20, 28.7% SiO2, 200 ppm Al), 69.4 grams of water and 0.3 grams of dispersant Daxad 27 was added with vigorous stirring. The reaction mixture, with a molar composition identical to that of Example 2, was then heated at 160C for crystallization. Crystallization was complete a~ter 461 hours.
The product had the X-ray dif~raction pattern o~ ZSM-5 and crystallinity was 80% compared with the reference sample containlng no boron or iron.
The chemical composition oF the product metallosilicate, in weight %, was:
SiO2 84.0 A1203 0.20 2 3 0.32 2 3 3.0 Na20 0.70 N 0.79 Ash 87.7 SiO2/~Al~B~Fe)203, molar 55.3 B203/(A1~3~Fe)203, molar 0.182 Fe203/(Al+B+Fe)2o3, molar 0.741 A1203/(Al+B+Fe)203, molar 0.077 The sorpton capacities of the product solid, calcined at 538C in air for 3 hours, in 9/lOO9, were:
Cyclohexane, 20 Torr 6.2 n-Hexane, 20 Torr 9.7 Water, 12 Torr 7.6 Example 5 ( A 0.75 gram quantity of iron-III sulfate, Fe2(504)3 7.1H20 and 45.3 grams of tetrapropylammonium brornide were dissolved in 120 grams of water. A 2 ml solution of gallium chloride containing 0.1 gram Ga/ml, and a solution of 4.5 grams of sodium hydroxide (97.6%~ in 52.5 grams of water were added.
Finally, 55 grams of Ludox LS (silica sol, 30% SiO2) was added with stirring. The well-mixed reaction mixture was digested at 200C in a stainless steel autoclave equipped with a Teflon liner.
Crystallization was complete after 230 hours. The product was filtered, washed with water until free of bromide and dried at ambient temperature.
The product had the X-ray diffraction pattern of ZSM-5 and crystallinity was 115% compared with a reference sample containing no iron or gallium.
The chemical composition of the product metallosilicate was:
SiO2, wt.% 83.9 A123' ppm 590 Ga203, wt.% 1.49 Fe203, wt.% 1.10 Na20, wt.% 0.56 N, wt.% 0.78 Ash, wt.% 86.0 SiO2/(Al+Ga~Fe)203, molar 90.8 Fe/(Al+Ga+Fe), atomic 0.45 Ga/(Al+Ga+Fe), atomic 0.52 The sorption capacities of the product solid, calcined at 538C in air for 3 hours, in 9/1009, were:
Cyclohexane, 40 Torr 7.7 n-Hexane, 40 Torr 11.9 Water, 12 Torr 6.8 Example 6 A 2.4 gram quantity of iron-III sulfate, Fe2(S04)3 7.1H20 and 45.6 grams of tetrabutylammonium bromide were dissolved A * Trade IndrJ~
in 120 srams of water. A 4.7 ml gallium chloride solution containing 0.1 gram Ga/ml and a solution of 5.8 grams of sodium hydroxide (97.6%) in 11 grams of water were added, followed by the addition of 110.5 grams of Ludox LS (silica sol, 30% SiO2), with stirring. The reaction mixture was then heated in a Teflon-lined stainless steel autoclave at 140C for 450 hours. The product was filtered, washed with water and dried at ambient temperature. It gave the X-ray diffraction pattern of ZSM-ll having 125%
crystallinity, relative to a reference sample, and contained a trace of an unidentified crystalline material.
Chemical composition of the product metallosilicate was determined and is listed below:
SiO2, wt.% 79.9 A123' ppm 770 Ga203, wt.% 1.75 Fe23' wt.~ 2.0 Na20, wt.% 1.02 N, wt.~ 0.81 Ash, wt.% 84.8 SiO2/(Al~Ga+Fe)203, molar 59.0 Ga/(Al+Ga+Fe), atomic 0.41 Fe/(Al+Ga+Fe), atomic 0.55 The sorption capacities of the calcined product of this Example, in 9/1009, were:
Cyclohexane9 40 Torr 11.6 n-Hexane, 40 Torr 12.1 Water, 12 Torr 11.3 Example 7 Boric acid, 0.65 gram, and 1.9 grams of iron-III sulfate, Fe2(504)3 7.1H20, were dissolved in 50 grams of water. A
solution of 3.3 grams of sodium hydroxide in 50 grams of water was added to a solution of 22.8 grams of tetrabutylammonium bromide in 100 grams of water, and the mixed solution was added to the
30Cyclohexane, 20 Torr 6.3 n-Hexane, 20 Torr 9.1 Water, 12 Torr 5.8 ~2~3~
Example 3 A 1.85 gram quantity of ferric sulfate, Fe2(S04)3 7.1 H20, was dissolved in 46.6 grams of water.
Ten grams of concentrated sulfuric acid was added with stirring, followed by a solution of 0.5 gram o~ boric acid in 35.1 grams of a 29.8% solution of tetrapropylammonium bromide. Sodium sulfate, Na2S04, 6.5 grams, was added and dissolved. Finally, a mixture of 120.0 grams of sodium silicate (8.9% Na20, 28.7% SiO2, 200 ppm Al), 69.4 grams of water and 0.3 grams of the dispersant Daxad 27 was added with vigorous stirring. The reaction mixture, identical in molar composition to that of Example 1, was then heated at 160C For crystallization. Crystallization was complete after 316 hours.
The product had the X-ray di~fraction pat~ern of ZSM-5 and crystallinity was 90% compared with the re~erence sample contaIning no boron or iron.
The chemical composition of the product metallosilicate, in weight %, was:
SiO2 85.2 A1203 0.24 ~23 0.52 Fe203 1.71 Na20 0.47 N 1.01 Ash 88.2 SiO2/(Al+S+Fe)203, molar 69.2 B203/(Al+8+Fe)203, molar 0.431 Fe203/(Al+B+Fe)203, molar 0.432 A1203/(Al+B+Fe)203, molar 0.137 The sorption capacities o~ the product solid, calcined at 538C in air for 3 hours, in 9/lOO9, were:
Cyclohexane, 20 Torr 7.0 n-Hexane, 20 Torr 10.3 Water, 12 Torr 7.0 Example 4 A 3.7 gram quantity of ferric sulfate, Fe2(S04)3 7.1 H20, was dissolved in 46.6 grams of water.
Eight grams of concentrated sulfuric acid was added with stirring, followed by a solution of 1 gram of boric acid in 35.1 grams of a 29.8% solution of tetrapropylammoniurn bromide. Sodium sulfate, Na2504, 6.5 grams was added and dissolved. Finally, a mixture of 120.0 grams of sodium silicate (8.9% Na20, 28.7% SiO2, 200 ppm Al), 69.4 grams of water and 0.3 grams of dispersant Daxad 27 was added with vigorous stirring. The reaction mixture, with a molar composition identical to that of Example 2, was then heated at 160C for crystallization. Crystallization was complete a~ter 461 hours.
The product had the X-ray dif~raction pattern o~ ZSM-5 and crystallinity was 80% compared with the reference sample containlng no boron or iron.
The chemical composition oF the product metallosilicate, in weight %, was:
SiO2 84.0 A1203 0.20 2 3 0.32 2 3 3.0 Na20 0.70 N 0.79 Ash 87.7 SiO2/~Al~B~Fe)203, molar 55.3 B203/(A1~3~Fe)203, molar 0.182 Fe203/(Al+B+Fe)2o3, molar 0.741 A1203/(Al+B+Fe)203, molar 0.077 The sorpton capacities of the product solid, calcined at 538C in air for 3 hours, in 9/lOO9, were:
Cyclohexane, 20 Torr 6.2 n-Hexane, 20 Torr 9.7 Water, 12 Torr 7.6 Example 5 ( A 0.75 gram quantity of iron-III sulfate, Fe2(504)3 7.1H20 and 45.3 grams of tetrapropylammonium brornide were dissolved in 120 grams of water. A 2 ml solution of gallium chloride containing 0.1 gram Ga/ml, and a solution of 4.5 grams of sodium hydroxide (97.6%~ in 52.5 grams of water were added.
Finally, 55 grams of Ludox LS (silica sol, 30% SiO2) was added with stirring. The well-mixed reaction mixture was digested at 200C in a stainless steel autoclave equipped with a Teflon liner.
Crystallization was complete after 230 hours. The product was filtered, washed with water until free of bromide and dried at ambient temperature.
The product had the X-ray diffraction pattern of ZSM-5 and crystallinity was 115% compared with a reference sample containing no iron or gallium.
The chemical composition of the product metallosilicate was:
SiO2, wt.% 83.9 A123' ppm 590 Ga203, wt.% 1.49 Fe203, wt.% 1.10 Na20, wt.% 0.56 N, wt.% 0.78 Ash, wt.% 86.0 SiO2/(Al+Ga~Fe)203, molar 90.8 Fe/(Al+Ga+Fe), atomic 0.45 Ga/(Al+Ga+Fe), atomic 0.52 The sorption capacities of the product solid, calcined at 538C in air for 3 hours, in 9/1009, were:
Cyclohexane, 40 Torr 7.7 n-Hexane, 40 Torr 11.9 Water, 12 Torr 6.8 Example 6 A 2.4 gram quantity of iron-III sulfate, Fe2(S04)3 7.1H20 and 45.6 grams of tetrabutylammonium bromide were dissolved A * Trade IndrJ~
in 120 srams of water. A 4.7 ml gallium chloride solution containing 0.1 gram Ga/ml and a solution of 5.8 grams of sodium hydroxide (97.6%) in 11 grams of water were added, followed by the addition of 110.5 grams of Ludox LS (silica sol, 30% SiO2), with stirring. The reaction mixture was then heated in a Teflon-lined stainless steel autoclave at 140C for 450 hours. The product was filtered, washed with water and dried at ambient temperature. It gave the X-ray diffraction pattern of ZSM-ll having 125%
crystallinity, relative to a reference sample, and contained a trace of an unidentified crystalline material.
Chemical composition of the product metallosilicate was determined and is listed below:
SiO2, wt.% 79.9 A123' ppm 770 Ga203, wt.% 1.75 Fe23' wt.~ 2.0 Na20, wt.% 1.02 N, wt.~ 0.81 Ash, wt.% 84.8 SiO2/(Al~Ga+Fe)203, molar 59.0 Ga/(Al+Ga+Fe), atomic 0.41 Fe/(Al+Ga+Fe), atomic 0.55 The sorption capacities of the calcined product of this Example, in 9/1009, were:
Cyclohexane9 40 Torr 11.6 n-Hexane, 40 Torr 12.1 Water, 12 Torr 11.3 Example 7 Boric acid, 0.65 gram, and 1.9 grams of iron-III sulfate, Fe2(504)3 7.1H20, were dissolved in 50 grams of water. A
solution of 3.3 grams of sodium hydroxide in 50 grams of water was added to a solution of 22.8 grams of tetrabutylammonium bromide in 100 grams of water, and the mixed solution was added to the
3'~
boron-iron solution. Finally, 90 grams o~ Ludox LS (silica sol, 30%
Siû2) was added with stirring. The reaction mixture was heated at 140C for 235 hours. The crystalline product was filtered, washed with water and dried at ambient temoerature.
X-ray analysis of the product solid indicated it to have the structure of ZSM-ll.
The chemical composition of the metallosilicate product of this example was SiO2~by diff), wt.~ 81.15 Q1203, ppm 455 B203, wt.~ 0.45 Fe23 9 wt.% 1.9 Na20, wt.% 0.62 N, wt.% 0.68 Ash, wt.% 84.4 SiO~/(Ql-~B-~Fe)20~, molar 72.0 ~/(A1~3~Fe), atomic 0.34 Fe/(Al+B~Fe), atomlc 0.63 The sorption capacities of the calcined product solid, in 9/lOO9, were:
Cyclohexane, 20 Torr 902 n-Hexane, 20 Torr 10.7 Water, 12 Torr 5.6 Example 8 Ten grams of the product crystals of Example 1 was heated in a tube furnace in a nitrogen stream (50 cc N2/min) -to 2~0C.
Ammonia gas (50 cc/min) was added to the nitrogen (Nrl3/N2 = 1~, and the heating was continued to 600C. The sample was held at this temperature for one hour and was then cooled to room temperature in the N2/NH3 atmosphere. The calcined material was treated -three times for one hour at 82C with 500 cc of a solution containing a 0.1 N concentration of ammonium chloride and a 1 N concentration of F-3252 --2 ~
ammonium hydroxide. The product was filtered, washed with O.lN
NH40H until free of chloride, and dried at ambient temperature.
The ammonium exchanged product had the following composition, in weight %:
SiO2 (by diff.) 92.6 Fe203 1.86 23 0.32 Na 0~01 N 0.55 Ash 95.1 SiO2/(A1203+Fe203~0203), molar 80.5 B23/(B23~Fe23~A123), molar 0.2~0 Fe23/(a23~Fe23+A123), molar 0.6Q7 A123/(B23+Fe23~A123), molar 0.153 N/(B-~Fe~Al), atomic 1.02 ~xarnple 9 Ten grams of the Example 7 product was heated in a tube furnace in a nitrogen stream (50 cc N2/min) to 200C. Ammonia gas (50 cc/min) was added to the nitrogen stream, and the heating was continued to 550C. The sample was held at this temperature for one hour and was then cooled to room temperature in the N2/NH3 atmosphere. The calcined material was treated three times for two hours at 71C with 500 cc of a solution containing O.lN
concentration of sodium hydroxide. The product was filtered, washed with O.OOlN NaOH until free of chloride, and dried at ambient temperature.
The sodium form product had the following composition, in weight %:
SiO2 91.6 A123' ppm 930 Fe203 2.43 2 3 0.39 ~2~3f~
Na20 1.62 N 0.03 Ash 94.6 SiO2/(A1203+Fe20~+B203), molar B23/(A123~Fe23+B23), molar 0.258 2 3/( 2 3 2 3 2 3)' A1203/(A1~03~Fe203~B203), molar 0.042 Na/(Al+Fe~8), atomic 1.20 Example 10 Six grams of the sodium form product from Example 9 was treated three times for two hours at 71C with 300 cc of a solution containing a 0.1 N concentration of ammonium chloride and a 0.1 N
concentration of ammonium hydroxide. The product was filtered, washed with 0.01 N NH40H until free of chloride, and dried at amblent temperature.
The back-exchanged product had the ~ollowing composition, in wt.%:
Si2 ~37.0 Q1203~ ppm 380 Fe203 2.43 B203 0.26 Na, ppm 40 N 0.53 Ash 93.8 SiO2/(A1203+Fe203+B203), molar 75.1 2 3/(A123~Fe23+323), molar 0.194 2o3/(A12o3+Fe2o3~B2o3)~ molar 0.787 A1203/(A1203+Fe203+3203), molar 0.019 N/(Al+Fe-~B), atomic 0.98 Na/(Al+Fe+B), atomic 0.005 Although a relatively large amount of boron was lost in this back-exchange, the remaining Al, Fe and B are in the framework of the zeolite (cation/(Al~Fe~B) 1).
F-3252 --26-~
A temperature-programmed ammonia desorption (TPAD) test was conducted on product samples frorn Examples 5 and 6 with the following approximate results (Table) confirming the conclusion that a new type of 3cid site is unexpectedly formed by the present acid strength-tailoring method.
Table Example Product TPAD Peak, C 330C 330C
Width at Half-Height, C 143C 143C
As a reference, it is noted that, at the above conditions for TPAD testing, an aluminosilicate zeolite of ZSM-5 structure prepared as taught in U.S. Patent 3,7û2,886 exhiblts a TPAD peak of 390C.
This evidence leads to the unexpected result that, at the above-noted conditions for TPAD testing, the acid strength-tailore zeolite of the present invention will exhibit a TPAD peak of less than about 390C, and depending on the Fe/(Fe+Al-tGa+B), the Ga/(Fe+Al+Ga+B) and the A1/(Fe+Al+Ga+B) atomic ratios of the zeolite, a TPAD peak of from greater than about 300C to less than about 390C. Further, at the above-noted TPAD test conditions, the acid strength-tailored zeolite of the present invention will exhibit a TPAD half-height width of less than about 155C, and depending on the Fe/(Fe+Al~Ga+B), the Ga/(Fe+AltGa+B) and the Al/(Fe+Al~Ga+B) atornic ratios of the zeolite, a TPAD half-height width of from greater than about 135C to less than about 155C.
boron-iron solution. Finally, 90 grams o~ Ludox LS (silica sol, 30%
Siû2) was added with stirring. The reaction mixture was heated at 140C for 235 hours. The crystalline product was filtered, washed with water and dried at ambient temoerature.
X-ray analysis of the product solid indicated it to have the structure of ZSM-ll.
The chemical composition of the metallosilicate product of this example was SiO2~by diff), wt.~ 81.15 Q1203, ppm 455 B203, wt.~ 0.45 Fe23 9 wt.% 1.9 Na20, wt.% 0.62 N, wt.% 0.68 Ash, wt.% 84.4 SiO~/(Ql-~B-~Fe)20~, molar 72.0 ~/(A1~3~Fe), atomic 0.34 Fe/(Al+B~Fe), atomlc 0.63 The sorption capacities of the calcined product solid, in 9/lOO9, were:
Cyclohexane, 20 Torr 902 n-Hexane, 20 Torr 10.7 Water, 12 Torr 5.6 Example 8 Ten grams of the product crystals of Example 1 was heated in a tube furnace in a nitrogen stream (50 cc N2/min) -to 2~0C.
Ammonia gas (50 cc/min) was added to the nitrogen (Nrl3/N2 = 1~, and the heating was continued to 600C. The sample was held at this temperature for one hour and was then cooled to room temperature in the N2/NH3 atmosphere. The calcined material was treated -three times for one hour at 82C with 500 cc of a solution containing a 0.1 N concentration of ammonium chloride and a 1 N concentration of F-3252 --2 ~
ammonium hydroxide. The product was filtered, washed with O.lN
NH40H until free of chloride, and dried at ambient temperature.
The ammonium exchanged product had the following composition, in weight %:
SiO2 (by diff.) 92.6 Fe203 1.86 23 0.32 Na 0~01 N 0.55 Ash 95.1 SiO2/(A1203+Fe203~0203), molar 80.5 B23/(B23~Fe23~A123), molar 0.2~0 Fe23/(a23~Fe23+A123), molar 0.6Q7 A123/(B23+Fe23~A123), molar 0.153 N/(B-~Fe~Al), atomic 1.02 ~xarnple 9 Ten grams of the Example 7 product was heated in a tube furnace in a nitrogen stream (50 cc N2/min) to 200C. Ammonia gas (50 cc/min) was added to the nitrogen stream, and the heating was continued to 550C. The sample was held at this temperature for one hour and was then cooled to room temperature in the N2/NH3 atmosphere. The calcined material was treated three times for two hours at 71C with 500 cc of a solution containing O.lN
concentration of sodium hydroxide. The product was filtered, washed with O.OOlN NaOH until free of chloride, and dried at ambient temperature.
The sodium form product had the following composition, in weight %:
SiO2 91.6 A123' ppm 930 Fe203 2.43 2 3 0.39 ~2~3f~
Na20 1.62 N 0.03 Ash 94.6 SiO2/(A1203+Fe20~+B203), molar B23/(A123~Fe23+B23), molar 0.258 2 3/( 2 3 2 3 2 3)' A1203/(A1~03~Fe203~B203), molar 0.042 Na/(Al+Fe~8), atomic 1.20 Example 10 Six grams of the sodium form product from Example 9 was treated three times for two hours at 71C with 300 cc of a solution containing a 0.1 N concentration of ammonium chloride and a 0.1 N
concentration of ammonium hydroxide. The product was filtered, washed with 0.01 N NH40H until free of chloride, and dried at amblent temperature.
The back-exchanged product had the ~ollowing composition, in wt.%:
Si2 ~37.0 Q1203~ ppm 380 Fe203 2.43 B203 0.26 Na, ppm 40 N 0.53 Ash 93.8 SiO2/(A1203+Fe203+B203), molar 75.1 2 3/(A123~Fe23+323), molar 0.194 2o3/(A12o3+Fe2o3~B2o3)~ molar 0.787 A1203/(A1203+Fe203+3203), molar 0.019 N/(Al+Fe-~B), atomic 0.98 Na/(Al+Fe+B), atomic 0.005 Although a relatively large amount of boron was lost in this back-exchange, the remaining Al, Fe and B are in the framework of the zeolite (cation/(Al~Fe~B) 1).
F-3252 --26-~
A temperature-programmed ammonia desorption (TPAD) test was conducted on product samples frorn Examples 5 and 6 with the following approximate results (Table) confirming the conclusion that a new type of 3cid site is unexpectedly formed by the present acid strength-tailoring method.
Table Example Product TPAD Peak, C 330C 330C
Width at Half-Height, C 143C 143C
As a reference, it is noted that, at the above conditions for TPAD testing, an aluminosilicate zeolite of ZSM-5 structure prepared as taught in U.S. Patent 3,7û2,886 exhiblts a TPAD peak of 390C.
This evidence leads to the unexpected result that, at the above-noted conditions for TPAD testing, the acid strength-tailore zeolite of the present invention will exhibit a TPAD peak of less than about 390C, and depending on the Fe/(Fe+Al-tGa+B), the Ga/(Fe+Al+Ga+B) and the A1/(Fe+Al+Ga+B) atomic ratios of the zeolite, a TPAD peak of from greater than about 300C to less than about 390C. Further, at the above-noted TPAD test conditions, the acid strength-tailored zeolite of the present invention will exhibit a TPAD half-height width of less than about 155C, and depending on the Fe/(Fe+Al~Ga+B), the Ga/(Fe+AltGa+B) and the Al/(Fe+Al~Ga+B) atornic ratios of the zeolite, a TPAD half-height width of from greater than about 135C to less than about 155C.
Claims (8)
1. A synthetic crystalline siliceous molecular sieve material having the structure of zeolite ZSM-5, zeolite ZSM-11 or zeolite ZSM-12 and containing aluminum and at least two elements selected from the group consisting of boron, gallium and iron in its anionic framework, said crystalline material having a composition on an anhydrous basis and in terms of moles of oxides per mole of silica expressed by the formula:
a R2/nO : b Fe2O3 : c B2O3 : d Ga2O3 : e A12O3 : SiO2 wherein R is at least one cation having the valence n, and a = (1.0?0.2)(b+c+d+e) b = 0 to 0.05 c = 0 to 0.05 d = 0 to 0.05 e = 0.00003 to 0.02 b+c+d+e = 0.005 to 0.05 b+c+d ? 0.00047 and wherein only one of b, c and d can be 0, and said crystalline material having, when in the ammonium form, a TPAD
(temperature-programmed ammonia desorption) peak of from greater than about 300°C to less than about 390°C and a TPAD half-height width from greater than 135°C to less than 155°C.
a R2/nO : b Fe2O3 : c B2O3 : d Ga2O3 : e A12O3 : SiO2 wherein R is at least one cation having the valence n, and a = (1.0?0.2)(b+c+d+e) b = 0 to 0.05 c = 0 to 0.05 d = 0 to 0.05 e = 0.00003 to 0.02 b+c+d+e = 0.005 to 0.05 b+c+d ? 0.00047 and wherein only one of b, c and d can be 0, and said crystalline material having, when in the ammonium form, a TPAD
(temperature-programmed ammonia desorption) peak of from greater than about 300°C to less than about 390°C and a TPAD half-height width from greater than 135°C to less than 155°C.
2. A method for synthesizing a crystalline siliceous molecular sieve material having the structure of zeolite ZSM-5, zeolite ZSM-11 or zeolite ZSM-12 and containing aluminum and at least two or three elements selected from the group consisting of boron, gallium and iron in its anionic framework which comprises preparing a mixture containing a source of organic cations, a source of silica, a source of alumina, a source of alkali or alkaline earth metal ions, water and sources of oxides of at least two metals selected from the group consisting of boron, gallium and iron, said mixture having a composition, in terms of moles of oxides, within the following ranges:
OH-/SiO2 = 0.02 to 0.85 H2O/OH = 10 to 800 SiO2/A1203 = 75 to 100,000 Q/(Q+M) = 0.05 to 0.90 when boron source present, SiO2/B2O3 = 4 to 600 when gallium source present, SiO2/Ga2O3 = 25 to 2,500 when iron source present, SiO2/Fe2O3 = 25 to 2,500 wherein Q represents organic cations and M represents alkali or alkaline earth metal ions, maintaining said mixture until said crystalline material is formed at a tennperature of from 80°C to 200°C for a time of frorn 40 hours to 30 days, and recovering said crystalline material having a composition on an anhydrous basis and in terms of moles of oxides per rnole of silica expressed by the formula:
a R2/nO : b Fe2O3 : c B2O3 : d Ga2O3 : e A12O3 : SiO2 wherein R is at least one cation having the valence n and a = (1.0?0.2)(b+c+d+e) b = 0 to 0.05 c = 0 to 0.05 d = 0 to 0.05 e = 0.00003 to 0.02 b+c+d+e = 0.0005 to 0.05 b+c+d ? 0.00047 and wherein only one of b, c and d can be 0, and said crystalline material having, when in the ammonium form, a TPAD (temperature-programmed ammonia desorption) peak of from greater than 300°C to less than 390°C and a TPAD half-height widthof from greater than 135°C to less than 155°C.
OH-/SiO2 = 0.02 to 0.85 H2O/OH = 10 to 800 SiO2/A1203 = 75 to 100,000 Q/(Q+M) = 0.05 to 0.90 when boron source present, SiO2/B2O3 = 4 to 600 when gallium source present, SiO2/Ga2O3 = 25 to 2,500 when iron source present, SiO2/Fe2O3 = 25 to 2,500 wherein Q represents organic cations and M represents alkali or alkaline earth metal ions, maintaining said mixture until said crystalline material is formed at a tennperature of from 80°C to 200°C for a time of frorn 40 hours to 30 days, and recovering said crystalline material having a composition on an anhydrous basis and in terms of moles of oxides per rnole of silica expressed by the formula:
a R2/nO : b Fe2O3 : c B2O3 : d Ga2O3 : e A12O3 : SiO2 wherein R is at least one cation having the valence n and a = (1.0?0.2)(b+c+d+e) b = 0 to 0.05 c = 0 to 0.05 d = 0 to 0.05 e = 0.00003 to 0.02 b+c+d+e = 0.0005 to 0.05 b+c+d ? 0.00047 and wherein only one of b, c and d can be 0, and said crystalline material having, when in the ammonium form, a TPAD (temperature-programmed ammonia desorption) peak of from greater than 300°C to less than 390°C and a TPAD half-height widthof from greater than 135°C to less than 155°C.
3. The method of Claim 2 wherein said mixture composition is:
OH-/SiO2 0.02 to 0.70 H2O/OH- 10 to 400 SiO2/A12O3 100 to 100,000 Q/(Q+M) 0.05 to 0.90 when boron source present, SiO2/B2O3 4 to 300 when gallium source present, SiO2/Ga2O3 25 to 2,500 when iron source present, SiO2/Fe2O3 25 to 2,500 and said recovered crystalline material has the structure of zeolite ZSM-5.
OH-/SiO2 0.02 to 0.70 H2O/OH- 10 to 400 SiO2/A12O3 100 to 100,000 Q/(Q+M) 0.05 to 0.90 when boron source present, SiO2/B2O3 4 to 300 when gallium source present, SiO2/Ga2O3 25 to 2,500 when iron source present, SiO2/Fe2O3 25 to 2,500 and said recovered crystalline material has the structure of zeolite ZSM-5.
4. The method of Claim 2 wherein said mixture composition is:
OH-/SiO2 0.02 to 0.80 H2O/OH- 25 to 800 SiO2/A12O3 100 to 100,000 Q/(Q+M) 0.05 to 0080 when boron source present, SiO2/B203 4 to 300 when gallium source present, SiO2/Ga203 25 to 2,500 when iron source present9 SiO2/Fe203 25 to 2,500 and said recovered crystalline material has the structure of zeolite ZSM-11.
OH-/SiO2 0.02 to 0.80 H2O/OH- 25 to 800 SiO2/A12O3 100 to 100,000 Q/(Q+M) 0.05 to 0080 when boron source present, SiO2/B203 4 to 300 when gallium source present, SiO2/Ga203 25 to 2,500 when iron source present9 SiO2/Fe203 25 to 2,500 and said recovered crystalline material has the structure of zeolite ZSM-11.
is 5. The method of Claim 2 whereln said mixture composition OH-/SiO2 0.10 to 0.85 H20/OH- 20 to 300 SiO2/A1203 75 to 100,000 Q/(Q+M) 0.20 to 0.90 when boron source presentt SiO2/B203 5 to 600 when gallium source present, SiO2/Ga203 30 to 2,5000 when iron source present, SiO2/Fe203 30 to 2,500 and said recovered crystalline material has the structure of zeolite ZSM-12.
6. The method of Claim 2, 3 or 4 which comprises heating said recovered crystalline material at a temperature of from 370°C to 1100°C.
7. 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 the crystalline material of Claim 1.
8. 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 a crystalline material produced by the method of Claim 2, 3 or 4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000494942A CA1251434A (en) | 1985-11-08 | 1985-11-08 | Crystalline molecular sieves and their synthesis |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000494942A CA1251434A (en) | 1985-11-08 | 1985-11-08 | Crystalline molecular sieves and their synthesis |
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| Publication Number | Publication Date |
|---|---|
| CA1251434A true CA1251434A (en) | 1989-03-21 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000494942A Expired CA1251434A (en) | 1985-11-08 | 1985-11-08 | Crystalline molecular sieves and their synthesis |
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| Country | Link |
|---|---|
| CA (1) | CA1251434A (en) |
-
1985
- 1985-11-08 CA CA000494942A patent/CA1251434A/en not_active Expired
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