Hydrocarbon conversion over ZSM-35

Information

  • Patent Grant
  • 4081490
  • Patent Number
    4,081,490
  • Date Filed
    Monday, November 8, 1976
    48 years ago
  • Date Issued
    Tuesday, March 28, 1978
    46 years ago
Abstract
Catalytic conversion of hydrocarbon compounds in the presence of crystalline zeolite ZSM-35, or a thermal decomposition product thereof, is provided. Zeolite ZSM-35 has a composition, in the anhydrous state, expressed in terms of mole ratios of oxides as follows:(0.3-2.5)R.sub.2 O:(0-0.8)M.sub.2 O : Al.sub.2 O.sub.3 : (x) SiO.sub.2wherein R is an organic nitrogen-containing cation derived from ethylenediamine or pyrrolidine, M is an alkali metal cation and x is greater than 8, and is characterized by a specified X-ray powder diffraction pattern.
Description

BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to hydrocarbon conversion in the presence of a novel crystalline aluminosilicate zeolite designated ZSM-35.
2. 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 conversions. Certain zeolitic materials are ordered, porous crystalline aluminosilicates having a definite crystalline structure within which there are a large number of smaller cavities which may be interconnected by a number of still smaller channels. These cavities and channels are precisely uniform in size. 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 aluminosilicates. These aluminosilicates can be described as a rigid three-dimensional framework of SiO.sub.4 and AlO.sub.4 in which the tetrahedra are cross-linked by the sharing of oxygen atoms whereby the ratio of the total aluminum and silicon atoms to oxygen 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 (Ca/2), (Sr/2), Na, K or Li is equal to unity. One type of cation may be exchanged either entirely or partially by 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. 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 aluminosilicates. These aluminosilicates have come to be designated by letter or other convenient symbols, as illustrated by zeolite A (U.S. Pat. No. 2,882,243), zeolite X (U.S. Pat. No. 2,882,244), zeolite Y (U.S. Pat. No. 3,130,007), zeolite ZK-5 (U.S. Pat. No. 3,247,195), zeolite ZK-4 (U.S. Pat. No. 3,314,752) and zeolite ZSM-5 (U.S. Pat. No. 3,702,886), merely to name a few.
One such crystalline aluminosilicate, a rare natural zeolite, is ferrierite. Ferrierite has been described by Grahm (Boy. Soc. Canada, Proc. and Trans., 3rd Ser., 12, 185-190) and by Staples (Am. Mineral. 40, 1095-99). The formula of the natural mineral ferrierite is given as (Na, K).sub.4 Mg.sub.2 (Si.sub.30 Al.sub.6) O.sub.72 (OH).sub.2 .18 H.sub.2 O. Barrer and Marshall (Am. Mineral. 50,484-85) in 1965 reexamined the X-ray powder diffraction pattern of a strontium zeolite Sr-D, synthesized by Barrer and Marshall in 1964 (J. Chem. Soc., 485-89) and concluded that it was closely related to natural ferrierite. A synthetic sodium form was briefly described by Senderov (Geokhimiya 9, 820-29) and a Ca-Na form of ferrierite produced by Coombs, Ellis, Fyfe and Taylor (Geochem. Cosmochim. Acta 17, 53-107) was not identified as such.
SUMMARY OF THE INVENTION
The present invention relates to the use of a synthetic crystalline aluminosilicate, hereinafter designated "zeolite ZDM-35" or simply "ZSM-35", as a catalyst for hydrocarbon conversion. The ZSM-35 composition has a characteristic X-ray diffraction pattern, the values of which are set forth in Table 1, hereinafter. The ZSM-35 composition can also be identified, in terms of mole ratios of oxides and in the anhydrous state, as follows:
(0.3-2.5)R.sub.2 O:(0-0.8)M.sub.2 O : Al.sub.2 O.sub.3 : (x) SiO.sub.2
wherein R is an organic nitrogen-containing cation derived from ethylenediamine or pyrrolidine, M is an alkali metal cation and x is greater than 8. It will be noticed that the ratio of R.sub.2 O to Al.sub.2 O.sub.3 may exceed unity in this material due to the occlusion of excess organic species (R.sub.2 O) within the zeolite pore.
ZSM-35 can further be characterized by its sorptive capacity at 90.degree. C, as will be hereinafter established.
In a preferred synthesized form, the zeolite has a formula, in terms of mole ratios of oxides and in the anhydrous state, as follows:
(0.4-2.5)R.sub.2 O:(0-0.6) M.sub.2 O : Al.sub.2 O.sub.3 : (y) SiO.sub.2
wherein R is an organic nitrogen-containing cation derived from ethylenediamine or pyrrolidine, M is an alkali metal, especially sodium, and y is from greater than 8 to about 50.
The original cations of the as synthesized ZSM-35 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, ammonium ions, hydrogen ions and mixtures thereof. Particularly preferred cations are those which render the zeolite catalytically active. These include hydrogen, rare earth metals, metals of Groups IB, IIB, IIIB, IVB, VIB, VIII, IIA, IIIA and IVA of the Periodic Table of Elements.
The synthetic ZSM-35 zeolite possesses a definite distinguishing crystalline structure whose X-ray diffraction pattern shows substantially the significant lines set forth in Table 1.
TABLE 1______________________________________d(A) I/Io______________________________________9.6 .+-. 0.20 Very strong-Very Very Strong7.10 .+-. 0.15 Medium6.98 .+-. 0.14 Medium6.64 .+-. 0.14 Medium5.78 .+-. 0.12 Weak5.68 .+-. 0.12 Weak4.97 .+-. 0.10 Weak4.58 .+-. 0.09 Weak3.99 .+-. 0.08 Strong3.94 .+-. 0.08 Medium-Strong3.85 .+-. 0.08 Medium3.78 .+-. 0.08 Strong3.74 .+-. 0.08 Weak3.66 .+-. 0.07 Medium3.54 .+-. 0.07 Very Strong3.48 .+-. 0.07 Very Strong3.39 .+-. 0.07 Weak3.32 .+-. 0.07 Weak-Medium3.14 .+-. 0.06 Weak-Medium2.90 .+-. 0.06 Weak2.85 .+-. 0.06 Weak2.71 .+-. 0.05 Weak2.65 .+-. 0.05 Weak2.62 .+-. 0.05 Weak2.58 .+-. 0.05 Weak2.54 .+-. 0.05 Weak2.48 .+-. 0.05 Weak______________________________________
These values were determined by standard techniques. The radiation was the K-alpha doublet of copper, and a scintillation counter spectrometer with a strip chart pen recorder was used. The peak heights, I, and the positions as a function of 2 times theta, where theta is the Bragg angle, were read from the spectrometer chart. From these, the relative intensities, 100 I/Io, where Io is the intensity of the strongest line or peak, and d (obs.), the intraplanar spacing in Angstrom units, corresponding to the recorded lines, were calculated. It should be understood that this X-ray diffraction pattern is characteristic of all the species of ZSM-35 compositions. Ion exchange of the sodium ion with cations reveals substantially the same pattern with some minor shifts in interplanar spacing and variation in relative intensity. Other minor variations can occur depending on the silicon to aluminum ratio of the particular sample, as well as if it has previously been subjected to thermal treatment.
A further characteristic of ZSM-35 is its sorptive capacity proving said zeolite to have increased capacity for 2-methylpentane (with respect to n-hexane sorption by the ratio n-hexane/2-methylpentane) when compared with a hydrogen form of natural ferrierite resulting from calcination of an ammonium exchanged form. The characteristic sorption ratio n-hexane/2-methylpentane for ZSM-35 (after calcination at 600.degree. C) is less than 10, whereas that ratio for the natural ferrierite is substantially greater than 10, for example, as high as 34 or higher.
While synthetic ZSM-35 zeolites may be used in a wide variety of hydrocarbon conversion reactions, they are notably useful in the processes of polymerization, aromatization and cracking. Other hydrocarbon conversion processes for which ZSM-35 may be utilized in one or more of its active forms include, for example, hydrocracking and converting light aliphatics to aromatics such as in U.S. Pat. No. 3,760,024.
Synthetic ZSM-35 zeolites can be used either in the organic nitrogen-containing and alkali metal containing form, the alkali metal form and hydrogen form or another univalent or multivalent cationic form. They can also be used in intimate combination with a hydrogenating component such as tungsten, vanadium, molybdenum, rhenium, nickel, cobalt, chromium, manganese, or a noble metal such as platinum or palladium where a hydrogenation-dehydrogenation function is to be performed. Such components can be exchanged into the composition, impregnated therein or physically intimately admixed therewith. Such components can be impregnated in or on to ZSM-35 such as, for example, by, in the case of platinum, treating the zeolite with a platinum metal-containing ion. Thus, suitable platinum compounds for this purpose include chloroplantinic acid, platinuous chloride and various compounds containing the platinum amine complex. Combinations of metals and methods for their introduction can also be used.
As prepared, R can be one or more of a variety of organic nitrogen-containing cations present in quantity of not less than 40% of the whole, examples of which include those cations derived from pyrrolidine and ethylenediamine.
Also, M can be one or more of a variety of alkali metal cations, suitably defined as including all alkali metal ions derived from alkali metal oxide or hydroxide as well as alkali metal ions included in alkali metal silicates and aluminates (not including alkali metal salts such as sodium chloride or sodium sulfate which may be derived from neutralization of added inorganic acids such as HCl or H.sub.2 SO.sub.4 or acid salts such as Al.sub.2 (SO.sub.4).sub.3. Non-limiting examples of such suitable alkali metal ions include sodium and potassium.
Zeolite ZSM-35 can be suitably prepared by preparing a solution containing sources of an alkali metal oxide, preferably sodium oxide, an organic nitrogen-containing oxide, an oxide of aluminum, an oxide of silicon and water and having a composition, in terms of mole ratios of oxides, falling within the following ranges:
______________________________________ Broad prefered______________________________________R.sup.+ /(R.sup.+ + M.sup.+) 0.2-1.0 0.3-0.9OH.sup.- /SiO.sub.2 0.05-0.5 0.07-0.49H.sub.2 O/OH.sup.- 41-500 100-250SiO.sub.2 /Al.sub.2 O.sub.3 8.8-200 12-60______________________________________
wherein R is an organic nitrogen-containing cation derived from ethylenediamine or pyrrolidine and M is an alkali metal ion, and maintaining the mixture until crystals of the zeolite are formed. (The quantity of OH.sup.- is calculated only from the inorganic sources of alkali without any organic base contribution). Thereafter, the crystals are separated from the liquid and recovered. Typical reaction conditions consist of heating the foregoing reaction mixture to a temperature of from about 90.degree. F to about 400.degree. F for a period of time of from about 6 hours to about 100 days. A more preferred temperature range is from about 150.degree. F to about 400.degree. F with the amount of time at a temperature in such range being from about 6 hours to about 80 days.
The digestion of the gel particles is carried out until crystals form. The solid product is separated from the reaction medium, as by cooling the whole to room temperature, filtering and water washing.
Synthetic ZSM-35, as a catalyst in the present hydrocarbon conversion process, should be dehydrated at least partially. This can be done by heating to a temperature in the range of 200 to 600.degree. C in an inert atmosphere, such as air, nitrogen, etc. and at atmospheric or subatmospheric pressures for between 1 and 48 hours. Dehydration can also be performed at lower temperature merely by placing the catalyst in a vacuum, but a longer time is required to obtain a sufficient amount of dehydration.
The composition for the synthesis of synthetic ZSM-35 can be prepared utilizing materials which can supply the appropriate oxide. Such compositions include aluminates, alumina, silicates, silica hydrosol, silica gel, silicic acid and hydroxides. It will be understood that each oxide component utilized in the reaction mixture for preparing ZSM-35 can be supplied by one or more essential reactions and they can be mixed together in any order. For example, any oxide can be supplied by an aqueous solution, sodium hydroxide or by an aqueous solution of a suitable silicate; the organic nitrogen-containing cation can be supplied by a compound of that cation, such as, for example, the hydroxide or a salt, as well as by the indicated amines. The reaction mixture can be prepared either batchwise or continuously. Crystal size and crystallization time of the ZSM-35 composition will vary with the nature of the reaction mixture employed.
DESCRIPTION OF SPECIFIC EMBODIMENTS
Synthetic ZSM-35 for use herein can have the original cations associated therewith replaced by a wide variety of other cations according to techniques well known in the art. Typical replacing cations include hydrogen, ammonium and metal cations including mixtures thereof. Of the replacing metallic cations, particular preference is given to cations of metals such as rare earth, Mn, Ca, Mg, Zn, Cd, Pd, Ni, Co, Ti, Al, Sn, Fe and Cu.
Typical ion exchange technique would be to contact the synthetic ZSM-35 zeolite with a salt of the desired replacing cation or cations. Although a wide variety of salts can be employed, particular preference is given to chlorides, nitrates and sulfates.
Representative ion exchange techniques are disclosed in a wide variety of patents including U.S. Pat. Nos. 3,140,249; 3,140,251; and 3,140,253.
Following contact with the salt solution of the desired replacing cation, the zeolite is then preferably washed with water and dried under conditions set forth hereinbefore to produce a catalytically-active thermal decomposition product thereof.
Regardless of the cations replacing the alkali metal in the synthesized form of the ZSM-35, the spacial arrangement of the aluminum, silicon and oxygen atoms which form the basic crystal lattices of ZSM-35 remains essentially unchanged by the described replacement of alkali metal as determined by taking an X-ray powder diffraction pattern of the ion-exchanged material.
The aluminosilicate prepared as indicated above is formed in 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 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 aluminosilicate can be extruded before drying or dried or partially dried and then extruded.
In the case of many catalysts, it is desired to incorporate the ZSM-35 with another material resistant to the temperatures and other conditions employed in organic conversion processes. Such matrix materials include active and inactive materials and synthetic or naturally occurring zeolites as well as inorganic materials such as clays, silica and/or metal oxides. The latter may be either naturally occurring or in the form of gelatinous precipitates, sols or gels including mixtures of silica and metal oxides. Use of a material in conjunction with the ZSM-35, i.e. combined therewith, which is active, tends to improve the conversion and/or selectivity of the 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. Frequently, zeolite materials have been incorporated into naturally occurring clays, e.g. bentonite and kaolin. These materials, i.e. clays, oxides, etc., function, in part, as binders for the catalyst. It is desirable to provide a catalyst having good crush strength, because in a petroleum refinery the catalyst is often subjected to rough handling, which tends to break the catalyst down into powder-like materials which cause problems in processing.
Naturally occurring clays which can be composited with the synthetic ZSM-35 catalyst include the montmorillonite and kaolin families which include the sub-bentonites, and the kaolins commonly known as Dixie, McNamee, Georgia and Florida clays or others in which the main mineral constituents 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 ZSM-35 catalyst for use herein can be composited with a porous matrix material such as 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 matrix can be in the form of a cogel. A mixture of these components could also be used. The relative proportions of finely divided crystalline aluminosilicate ZSM-35 and inorganic oxide gel matrix vary widely with the crystalline aluminosilicate content ranging from about 1 to about 90 percent by weight and more usually in the range of about 2 to about 50 percent by weight of the composite.
In general, hydrocarbon compounds may be catalytically converted in the presence of the ZSM-35 catalyst material, including the product of thermal treatment thereof, over a range of catalytic conversion conditions, including a reaction temperature of from about 100.degree. F to about 1200.degree. F, preferably from about 400.degree. F to about 1000.degree. F, a reaction pressure of from atmospheric to about 10,000 psig, preferably from about atmospheric to about 3,500 psig, and a hydrogen/hydrocarbon compound ratio of from 0 to about 20,000 scf/bbl, preferably from 0 to about 10,000 scf/bbl. When the conversion is conducted in a flow apparatus, e.g. a down-flow reactor, or under conditions comparable to those existing in a flow apparatus, the liquid hourly space velocity (LHSV) should be maintained at between about 0.1 hr.sup.-1 and about 50 hr.sup.-1, preferably between about 1 hr.sup.-1 and about 10 hr.sup.-1. When the conversion is conducted in a batch apparatus, e.g. a stirred batch reactor, or under conditions comparable to those existing in a batch apparatus, the contact time should be maintained at between about 0.01 hour and about 48 hours, preferably between about 0.1 hour and about 24 hours.
In particular, when the conversion of hydrocarbon compounds by the present method is olefin polymerization, catalytic conversion conditions should be maintained within certain critical ranges, including a temperature of from about 100.degree. F to about 900.degree. F, preferably from about 400.degree. F to about 800.degree. F, a pressure of from about atmospheric to about 4,000 psig, preferably from about atmospheric to about 2,000 psig, a LHSV (when a flow operation) of from about 0.1 hr.sup.-1 to about 50 hr.sup.-1, preferably from about 1 hr.sup.-1 to about 10 hr.sup.-1, and a contact time (when a batch operation) of from about 0.1 hour to about 48 hours, preferably from about 0.5 hour to about 24 hours and a hydrogen/hydrocarbon (i.e. olefin) ratio of from about 50 scf/bbl to about 10,000 scf/bbl, preferably from about 500 scf/bbl to about 5,000 scf/bbl.
When the conversion is olefin or paraffin aromatization, catalytic conversion conditions should be maintained within critical ranges, including a temperature of from about 600.degree. F to about 1200.degree. F, preferably from about 800.degree. F to about 1000.degree. F, a pressure of from about 50 psig to about 10,000 psig, preferably from about 100 psig to about 1,000 psig, a LHSV (when a flow operation) of from about 0.1 hr.sup.-1 to about 10 hr.sup.-1, preferably from about 1 hr.sup.-1 to about 5 hr.sup.-1, a contact time (when a batch operation) of from about 0.1 hour to about 48 hours, preferably from about 1 to about 24 hours and a hydrogen/hydrocarbon (i.e. olefin or paraffin) ratio of from about 50 scf/bbl to about 10,000 scf/bbl, preferably from about 100 scf/bbl to about 1,000 scf/bbl.
Further, when the conversion of hydrocarbon compound by the present method is cracking, catalytic conversion conditions should be maintained within certain critical ranges, including a temperature of from about 700.degree. F to about 1200.degree. F, preferably from about 800.degree. F to about 1000.degree. F, a pressure of from about atmospheric to about 200 psig, a LHSV (when a flow operation) of from about 0.5 hr.sup.-1 to about 50 hr.sup.-1, preferably from about 1 hr.sup.-1 to about 10 hr.sup.-1, and a contact time (when a batch operation) of from about 0.01 hour to about 24 hours, preferably from about 0.1 hour to about 10 hours. When the conversion is hydrocracking, catalytic conversion conditions should be maintained within somewhat different ranges, including a temperature of from about 400.degree. F to about 1000.degree. F, preferably from about 500.degree. F to about 850.degree. F, a pressure of from about 500 psig to about 3500 psig, a LHSV (when a flow operation) of from about 0.1 hr.sup.-1 to about 10 hr.sup.-1, preferably from about 0.2 hr.sup.-1 to about 5 hr.sup.-1, a contact time (when a batch operation) of from about 0.1 hour to about 10 hours, preferably from about 0.2 hour to about 5 hours and a hydrogen/hydrocarbon ratio of from about 1000 scf/bbl to about 20,000 scf/bbl, preferably from about 3,000 scf/bbl to about 10,000 scf/bbl.
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 which follow, whenever adsorption data are set forth for comparison of sorptive capacities for water, cyclohexane and n-hexane, they were determined as follows:
A weighed sample of the calcined zeolite was contacted with the desired pure adsorbate vapor in an adsorption chamber, evacuated to 12 mm when checking capacity for water and 20 mm when checking capacity for cyclohexane and n-hexane, pressures less than the vapor-liquid equilibrium pressure of the respective adsorbate at room temperature. The pressure was kept constant (within about .+-.0.5 mm) by addition of adsorbate vapor controlled by a manostat during the adsorption period which did not exceed about eight hours. As adsorbate was adsorbed by the zeolite, 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 sufficient to activate the monostat. The increase in weight was calculated as the adsorption capacity of the sample.
When the sorptive capacities for 2-methylpentane and n-hexane were measured for distinguishing comparisons of ratios of n-hexane/2-methylpentane sorption, a weighed sample of zeolite was heated to 600.degree. C and held at that temperature until the evolution of basic nitrogenous gases ceased. The zeolite was then cooled and the sorption test run essentially as above with the sorption being conducted at 90.degree. C and the sorbate being chilled at 0.degree. C.
EXAMPLE 1
Illustrating preparation of synthetic zeolite ZSM-35, a first solution comprising 3.3 g sodium aluminate (41.8% Al.sub.2 O.sub.3, 31.6% Na.sub.2 O and 24.9% H.sub.2 O), 87.0 g H.sub.2 O and 0.34 g NaOH (50% solution with water) was prepared. The organic material pyrrolidine was added to the first solution in 18.2 g quantity to form a second solution. Thereupon 82.4 g colloidal silica (29.5% SiO.sub.2 and 70.5% H.sub.2 O) was added to the second solution and mixed until a homogeneous gel was formed. This gel was composed of the following components in mole ratios:
______________________________________ ##STR1## = 0.87, wherein M is sodium and R.sup.+ is the pyrrolidine ion. ##STR2## = 0.094 (Not including any contribution of OH.sup.- from pyrrolidine) ##STR3## = 210 (Not including any contribution of OH.sup.- from pyrrolidine) ##STR4## = 30.0______________________________________
The mixture was maintained at 276.degree. F for 17 days, during which time crystallization was complete. The product crystals were filtered out of solution and water washed for approximately 16 hours on continuous wash line.
X-ray analysis of the crystalline product proved the crystals to have a diffraction pattern as shown below:
______________________________________2 Times Theta d(A) I/Io______________________________________7.70 11.48 59.28 9.53 12712.52 7.07 2512.78 6.93 2513.40 6.61 2715.38 5.76 1215.62 5.67 416.90 5.25 417.92 4.95 1018.75 4.73 519.40 4.58 422.32 3.98 6322.60 3.93 3923.13 3.85 2023.60 3.77 5123.85 3.73 1224.30 3.66 3325.21 3.53 10025.70 3.47 8026.30 3.39 2826.92 3.31 2428.53 3.13 1829.34 3.04 830.25 2.954 630.65 2.917 231.00 2.885 431.41 2.848 333.15 2.702 333.98 2.638 734.40 2.607 334.87 2.573 435.35 2.539 236.33 2.473 436.77 2.444 237.45 2.401 438.33 2.348 539.00 2.309 239.47 2.283 242.30 2.137 242.90 2.108 244.75 2.025 545.56 1.991 846.20 1.965 346.70 1.945 447.30 1.922 948.90 1.862 6______________________________________
Chemical analysis of the crystalline product led to the following compositional figures:
______________________________________Composition Wt. % Mole Ratio on Al.sub.2 O.sub.3 Basis______________________________________N 1.87 --Na 0.25 --Al.sub.2 O.sub.3 5.15 1.0SiO.sub.2 90.7 29.9N.sub.2 O -- 1.54Na.sub.2 O -- 0.11H.sub.2 O -- 9.90 (from H.sub.2 O adsorption)______________________________________
Physical analysis of the crystalline product of Example 1 calcined 16 hours at 1000.degree. F showed it to have a surface area of 304 m.sup.2 /g and adsorption tests (conducted as hereinbefore described) produced the following results:
______________________________________Adsorption Wt. %______________________________________Cyclohexane 1.0n-Hexane 5.4Water 9.0n-Hexane/2-methylpentane (90.degree. C) = 2.64______________________________________
EXAMPLE 2
A batch of ZSM-35 was prepared by first making a solution of 101.6g sodium silicate (28.8% SiO.sub.2, 8.9% Na.sub.2 O and 62.2% H.sub.2 O), 6.5g NaOH (50% solution) and 59.8g H.sub.2 O. Then 30.0g ethylenediamine was added to the first solution. To this mixture was added a solution comprised of 19.4g Al.sub.2 (SO.sub.4).sub.3.18H.sub.2 O, 4.5g H.sub.2 SO.sub.4 and 174g H.sub.2 O, and the resultant gel was mixed until homogeneous. This gel was composed of the following components in mole ratios:
______________________________________ ##STR5## = 0.82, wherein M is sodium and R is H.sub.2 N (CH.sub.2).sub.2 NH.sub.2 ##STR6## = 0.22 ##STR7## = 152 ##STR8## = 16.7______________________________________
The gel mixture was maintained at 210.degree. F for 62 days, during which time crystallization was complete. The product crystals were filtered out of solution and water washed.
X-ray analysis of the crystalline product proved the crystals to have a diffraction pattern as shown in Table 1 and chemical analysis proved them to have a mole ratio of SiO.sub.2 to Al.sub.2 O.sub.3 of 14.4.
In the aforementioned sorption test for measuring the distinctive sorption capacity ratio of n-hexane/2-methylpentane at 90.degree. C, the sample of ZSM-35 prepared according to this example sorbed 5.1 weight percent n-hexane and 2.8 weight percent 2-methylpentane (n-hexane/2-methylpentane = 1.82).
EXAMPLE 3
A quantity of natural ferrierite, with a mole ratio of SiO.sub.2 to Al.sub.2 O.sub.3 of 12 was calcined at 1000.degree. F for 10 hours and exchanged with ammonium chloride solution. The exchanged ferrierite was then dried at 230.degree. F for 16 hours and calcined at 1000.degree. F for 10 hours to produce the hydrogen form of the zeolite (H-ferrierite). Also, the zeolite ZSM-35 of Example 2 was processed as above to produce an HZSM-35 zeolite.
EXAMPLE 4
The H-ferrierite and HZSM-35 products of Example 3 were subjected to a modified version of the alpha-test described by P. B. Weisz and J. N. Miale in Journal of Catalysis, 4, 527-529 (1965) to determine cracking rate of n-hexane with the liquid hourly space velocity maintained at 1.0 and the temperature maintained at 800.degree. F. The alpha-test of this example differs from that described by Weisz and Miale only in that the feed here is a mixture of n-hexane, 3-methylpentane and 2,2-dimethylbutane. The results, indicating vast superiority of HZSM-35 in comparison with H-ferrierite in cracking activity, were as follows:
______________________________________ n-Hexane Cracking Rate .alpha. (5 minutesCatalyst after commencement of flow)______________________________________H-ferrierite 170HZSM-35 420______________________________________
EXAMPLE 5
A batch of the H-ferrierite product of Example 3 was subjected to the aforementioned sorption test for measuring the distinctive sorption capacity ratio of n-hexane/2-methylpentane at 90.degree. C. Results of that test showed sorption of 3.4 weight percent n-hexane and less than 0.1 weight percent 2-methylpentane (n-hexane/2-methylpentane =>34.)
EXAMPLES 6-8
The synthetic crystalline zeolite ZSM-35 preparations of Examples 6-8 are presented hereby in tabular form in Tables 2 and 2A. These examples were prepared while using ethylenediamine as the organic nitrogen-containing cation source, wherein R is H.sub.2 N(C.sub.2 H.sub.2).sub.2 NH.sub.2 and M is sodium. X-ray analysis of the products of each of Examples 6-8 proved them to have the diffraction patterns shown in Table 3.
TABLE 2__________________________________________________________________________ZSM-35 SYNTHESIS FROM ETHYLENEDIAMINE Crystallization Starting Gel, Molar Ratio Time,Example Preparation Notes R+/R+ + M+ OH.sup.- /SiO.sub.2 SiO.sub.2 /Al.sub.2 O.sub.3 H.sub.2 O/OH.sup.- Temp. .degree. F Days__________________________________________________________________________6 Components of Example 1(2) 0.87 0.19 14.6 205 350 107 Components of Example 1(2) 0.89 0.15 16.2 244 350 58 (1) 0.64 0.404 50.0 81.6 210 41__________________________________________________________________________(1) Components: First Solution Sodium silicate (28.8% SiO.sub.2, 8.9% Na.sub.2 O and 62.2% H.sub.2 O) Sodium hydroxide Water Second Solution Al.sub.2 (SO.sub.4).sub.3 . 18H.sub.2 O H.sub.2 SO.sub.4 Water Third Solution Contents of First Solution Ethylenediamine - Starting Gel Contents of Third Solution Contents of Second Solution(2) components of zeolite preparation reaction mixture excluding the source of organic nitrogen-containing cation.
TABLE 2A______________________________________ZSM-35 SYNTHESIS FROM ETHYLENEDIAMINEFinal FinalProduct Analysis Product Sorption Surfaceper mole Al.sub.2 O.sub.3 wt. % AreaExample N.sub.2 O Na.sub.2 O SiO.sub.2 H.sub.2 O Cy-C.sub.6 n-C.sub.6 m.sup.2 /gm______________________________________6 2.18 0.01 19.8 11.6 1.0 5.0 2837 1.87 -- 15.2 11.6 1.1 5.7 2998 1.94 -- 21.4 11.6 1.4 6.5 334______________________________________
TABLE 3______________________________________X-Ray Diffraction Patterns of ZSM-35 Prepared inExample 62 Times Theta d(A) I/Io______________________________________7.80 11.33 19.22 9.59 12412.50 7.08 2612.68 6.98 3813.35 6.63 2213.75 6.44 115.34 5.78 1015.60 5.68 617.85 4.97 618.35 4.83 118.72 4.74 319.42 4.57 122.29 3.99 7722.60 3.93 5023.12 3.85 2823.55 3.78 5523.80 3.74 624.32 3.66 3325.14 3.54 10025.61 3.48 8326.39 3.38 1526.92 3.31 1728.45 3.14 1529.30 3.05 1730.30 2.950 830.90 2.894 731.50 2.840 333.09 2.707 433.88 2.646 734.37 2.609 234.79 2.579 335.30 2.542 236.29 2.475 636.70 2.449 137.35 2.408 437.65 2.389 138.35 2.347 439.05 2.306 339.45 2.284 239.92 2.258 240.29 2.238 341.51 2.175 142.14 2.144 342.85 2.110 344.78 2.024 545.50 1.994 1146.25 1.963 146.65 1.947 447.29 1.922 1248.77 1.867 849.78 1.832 350.60 1.804 351.35 1.779 451.65 1.770 752.71 1.737 253.74 1.706 354.90 1.672 155.35 1.660 355.67 1.651 156.09 1.640 156.70 1.623 157.00 1.616 157.35 1.607 358.60 1.575 259.84 1.546 2______________________________________
TABLE 3______________________________________X-Ray Diffraction Patterns of ZSM-35 Prepared inExample 72 Times Theta d(A) I/Io______________________________________9.22 9.59 10612.40 7.14 2912.60 7.03 2513.26 6.68 1715.30 5.79 915.55 5.70 617.80 4.98 418.28 4.85 118.69 4.75 319.32 4.59 122.21 4.00 4822.51 3.95 4623.05 3.86 1923.46 3.79 5023.74 3.75 824.25 3.67 3425.05 3.55 10025.53 3.49 7726.30 3.39 1826.84 3.32 1728.35 3.15 2929.21 3.06 1230.20 2.959 930.80 2.903 631.40 2.849 232.98 2.716 533.78 2.653 534.22 2.620 234.72 2.584 435.27 2.545 236.17 2.483 636.72 2.447 137.20 2.417 637.70 2.386 138.25 2.353 438.98 2.310 239.32 2.291 239.80 2.265 139.98 2.255 140.16 2.245 241.50 2.176 142.04 2.149 242.72 2.116 344.65 2.029 345.35 2.000 1046.15 1.967 146.59 1.949 347.15 1.928 1248.62 1.873 749.60 1.838 250.45 1.809 251.15 1.786 351.49 1.775 652.55 1.741 253.54 1.711 254.79 1.675 155.23 1.663 355.73 1.649 156.52 1.628 156.85 1.620 157.13 1.612 258.45 1.579 259.12 1.563 159.90 1.544 2______________________________________
TABLE 3______________________________________X-Ray Diffraction Patterns of ZSM-35 Prepared inExample 82 Times Theta d(A) I/Io______________________________________9.24 9.57 10712.45 7.11 2612.65 7.00 4013.31 6.65 2615.30 5.79 1215.55 5.70 617.82 4.98 418.33 4.84 118.71 4.74 319.38 4.58 122.25 4.00 6722.55 3.94 4423.09 3.85 2823.50 3.79 5223.79 3.74 924.31 3.66 3025.10 3.55 10025.60 3.48 8326.35 3.38 1526.89 3.32 1728.42 3.14 2729.28 3.05 1530.25 2.954 830.86 2.897 731.40 2.849 333.02 2.713 533.82 2.650 834.20 2.622 234.75 2.582 335.28 2.544 236.25 2.478 636.58 2.456 137.30 2.411 437.56 2.395 238.33 2.348 339.00 2.309 339.41 2.286 239.92 2.258 240.25 2.240 341.52 2.175 142.13 2.145 342.82 2.112 344.72 2.026 545.45 1.996 1146.19 1.965 146.56 1.950 447.21 1.925 1148.75 1.868 849.75 1.833 350.55 1.806 351.28 1.782 351.55 1.773 752.62 1.739 253.70 1.707 254.90 1.672 255.32 1.661 355.75 1.649 156.57 1.627 156.90 1.618 257.31 1.608 358.55 1.576 259.10 1.563 159.80 1.546 2______________________________________
Further examples are presented by way of tabular accumulation of data as follows in Tables 4, 4A, 5 and 5A. Tables 4 and 4A show examples of preparation of ZSM-35 while using ethylenediamine as the organic nitrogen-containing cation source, wherein R is H.sub.2 N(C.sub.2 H.sub.2).sub.2 NH.sub.2 and M is sodium.
Tables 5 and 5A show examples of ZSM-35 preparation while using pyrrolidine as the source of organic nitrogen-containing cation. In each example of Tables 5 and 5A, R.sup.+ is the pyrrolidine ion and M is sodium.
X-ray analysis of the products of each of the examples presented in Tables 4, 4A, 5 and 5A proved them to have a diffraction pattern as shown in Table 1.
The full X-ray diffraction patterns for the zeolite ZSM-35 samples prepared in Examples 18 and 19 appear in Table 6.
TABLE 4__________________________________________________________________________ZSM-35 SYNTHESIS FROM ETHYLENEDIAMINE Crystallization Starting Gel, Molar Ratio Time,Example Preparation Notes R+/R+ + M+ OH.sup.- /SiO.sub.2 SiO.sub.2 /Al.sub.2 O.sub.3 H.sub.2 O/OH.sup.- Temp., .degree. F Days__________________________________________________________________________ 9 Components of Example 1 (2) 0.87 0.19 14.6 205 310 1610 Components of Example 1 (2) 0.89 0.15 16.2 244 210 15011 Components of Example 8 0.81 0.20 21.3 114 275 1412 Components of Example 8 0.81 0.20 21.3 114 350 513 Components of Example 8 0.62 0.32 22.0 108 210 10314 Components of Example 8 (1) 0.88 0.87 32.4 224 310 1115 Components of Example 1 (2) 0.88 0.086 32.4 224 210 9916 Components of Example 8 0.62 0.30 33.4 109 210 4117 Components of Example 8 0.69 0.30 33.4 109 210 62__________________________________________________________________________ (1) Sodium aluminate and silica of formula: 87.5% SiO.sub.2, 1.6% NaCl, 10.5% H.sub.2 O (2) Components of zeolite preparation reaction mixture excluding the source of organic nitrogen-containing cation.
TABLE 4A______________________________________ZSM-35 SYNTHESIS FROM ETHYLENEDIAMINEFinal ProductAnalysis per mole Final Product SurfaceAl.sub.2 O.sub.3 Sorption, wt. % AreaExample N.sub.2 O Na.sub.2 O SiO.sub.2 H.sub.2 O Cy-C.sub.6 n-C.sub.6 m.sup.2 /gm______________________________________ 9 1.93 0.11 19.2 9.1 0.6 3.8 27410 1.49 0.33 14.4 13.0 2.0 7.1 31211 -- -- -- 11.4 0.8 5.7 31212 1.6 0.05 14.8 10.6 0.9 6.4 29313 1.51 0.05 17.1 12.7 2.6 7.3 35214 1.45 0.07 16.7 9.8 0.5 4.5 26015 2.0 -- 25.9 8.5 3.8 9.0 34316 1.84 0.11 20.0 8.4 1.8 6.2 32317 1.95 0.24 20.9 10.3 0.4 5.8 295______________________________________
TABLE 5__________________________________________________________________________ZSM-35 SYNTHESIS FROM PYRROLIDINE Crystallization Starting Gel, Molar Ratio Time,Example Preparation Notes R+/R+ + M+ OH-/SiO.sub.2 SiO.sub.2 /Al.sub.2 O.sub.3 H.sub.2 O/OH.sup.- Temp., .degree. Days__________________________________________________________________________18 Components of Example 1 0.88 0.28 8.82 195 350 1019 Components of Example 1 0.74 0.17 15.2 231 350 1520 Components of Example 1 0.74 0.17 15.2 231 275 1121 Components of Example 1 0.74 0.17 15.2 231 350 522 Components of Example 1 0.87 0.097 29.0 202 270 1723 Components of Example 8 (1) 0.50 0.49 33.3 70.5 210 3624 Components of Example 8 (1) 0.68 0.32 33.6 108 210 2725 Components of Example 8 (1) 0.62 0.13 48.0 333 304 7__________________________________________________________________________ (1) Components of zeolite preparation reaction mixture excluding the source of organic nitrogen-containing cation.
TABLE 5A______________________________________ZSM-35 SYNTHESIS FROM PYRROLIDINEFinal ProductAnalysis per mole Final Product SurfaceAl.sub.2 O.sub.3 Sorption, wt. % AreaExample N.sub.2 O Na.sub.2 O SiO.sub.2 H.sub.2 O C.sub.y -C.sub.6 nC.sub.6 m.sup.2 /gm______________________________________18 -- -- -- 10.5 2.1 7.6 37019 0.89 0.28 18.6 10.0 0.8 4.6 23520 0.77 0.28 14.0 11.5 2.3 7.0 30621 0.74 0.25 14.1 10.0 1.1 6.3 24622 1.40 0.07 29.1 11.0 2.1 8.2 34923 0.68 0.28 14.3 8.3 3.9 4.3 34625 0.81 0.58 37.1 6.9 1.1 2.5 --______________________________________
TABLE 6______________________________________X-Ray Diffraction Patterns of ZSM-35 Prepared inExample 182 Times Theta d(A) I/Io______________________________________7.78 11.36 29.23 9.58 9612.48 7.09 2012.68 6.98 2713.34 6.64 2515.29 5.79 915.59 5.68 317.82 4.98 1218.35 4.83 218.69 4.75 219.35 4.59 122.28 3.99 8722.56 3.94 4623.08 3.85 3123.50 3.79 5423.79 3.74 1324.25 3.67 3725.11 3.55 10025.60 3.48 7926.32 3.39 1726.88 3.32 2128.40 3.14 2529.22 3.06 1330.20 2.959 830.85 2.898 531.35 2.853 433.00 2.714 433.83 2.650 734.25 2.618 234.75 2.582 435.20 2.550 136.23 2.479 637.25 2.414 538.25 2.353 438.96 2.312 239.40 2.287 239.92 2.258 140.23 2.242 341.52 2.175 142.15 2.144 342.80 2.113 344.69 2.028 545.42 1.997 946.09 1.969 246.60 1.949 547.17 1.927 1248.75 1.868 749.71 1.834 350.52 1.807 351.25 1.782 351.51 1.774 652.59 1.740 253.63 1.709 254.90 1.672 155.24 1.663 255.60 1.653 256.60 1.626 256.94 1.617 257.34 1.607 258.38 1.581 158.70 1.573 159.07 1.564 159.83 1.546 2______________________________________
TABLE 6______________________________________X-Ray Diffraction Patterns of ZSM-35 Prepared inExample 192 Times Theta d(A) I/Io______________________________________ 9.25 9.56 8812.49 7.09 1712.69 6.98 2213.35 6.63 2615.30 5.79 815.60 5.68 317.85 4.97 1018.41 4.82 218.78 4.72 219.37 4.58 222.26 3.99 7822.55 3.94 3123.09 3.85 2123.49 3.79 4123.75 3.75 1024.25 3.67 3125.10 3.55 10025.55 3.49 7426.30 3.39 1626.85 3.32 1928.40 3.14 2229.22 3.06 930.21 2.958 730.84 2.899 631.36 2.852 333.00 2.714 433.84 2.649 734.25 2.618 234.73 2.583 335.00 2.564 135.26 2.545 236.24 2.479 636.77 2.444 237.25 2.414 437.60 2.392 138.22 2.355 438.97 2.311 339.35 2.290 239.82 2.264 140.23 2.242 341.52 2.175 142.15 2.144 342.80 2.113 344.69 2.028 545.42 1.997 946.09 1.969 246.60 1.949 547.17 1.927 1248.75 1.868 749.71 1.834 350.52 1.807 351.25 1.782 351.51 1.774 652.59 1.740 253.63 1.709 254.90 1.672 155.24 1.663 255.60 1.653 256.60 1.626 256.94 1.617 257.34 1.607 258.38 1.581 158.70 1.573 159.07 1.564 159.83 1.546 2______________________________________
EXAMPLE 26
After 2 grams of the HZSM-35 product of Example 3 is pretreated with air flowing at 10 cc/minute for 2 hours at 1000.degree. F and then purged with helium flowing at 10 cc/minute for 1/2 hour while the temperature is dropped to 700.degree. F, propylene is contacted therewith at atmospheric pressure and in the presence of hydrogen applied at 2000 scf/bbl. The LHSV is maintained at 2. The research octane numbers of two different samples of product are determined to be 98.0 and 97.4. The HZSM-35 product of Example 3 at the end of the contacting contains 9.5 weight percent coke and a sample of composite olefinic liquid (192 grams) reduced over 1.0 gram of 10% Pd/C catalyst, consumes 2.29 moles of hydrogen.
EXAMPLE 27
Propylene is converted to an olefinic liquid product in this example over 0.26 grams of the HZSM-35 product of Example 3 at 800.degree. F and atmospheric pressure after the HZSM-35 is pretreated as in Example 26. Hydrogen is supplied to the reaction at 2000 scf/bbl and the LSHV is maintained at about 2 hr..sup.-1.
EXAMPLE 28
Butene-1 is converted to an olefinic liquid product in this example over 0.26 grams of the HZSM-35 product of Example 3 at 500.degree. F and about 1000 psig after the HZSM-35 is pretreated as in Example 26. Hydrogen is supplied to the reaction at 1000 scf/bbl and the LHSV is maintained at 1 hr..sup.-1.
Claims
  • 1. A process for effecting catalytic conversion of a hydrocarbon compound charge which comprises contacting said charge under catalytic conversion conditions with a catalyst comprising a synthetic crystalline aluminosilicate zeolite having a composition expressed in terms of mole ratios of oxides in the anhydrous state as follows:
  • (0.3-2.5)R.sub.2 O:(0-0.8)M.sub.2 O : Al.sub.2 O.sub.3 : (x) SiO.sub.2
  • wherein R is an organic nitrogen-containing cation derived from ethylenediamine or pyrrolidine, M is an alkali metal cation and x is greater than 8 and having an X-ray powder diffraction pattern as shown in Table 1 of the specification, or a thermal decomposition product thereof.
  • 2. The process of claim 1 wherein said catalyst has a composition in terms of mole ratios of oxides in the anhydrous state as follows:
  • (0.4-2.5)R.sub.2 O: (0-0.6)M.sub.2 O: Al.sub.2 O.sub.3 : (y) SiO.sub.2
  • wherein y is from greater than 8 to about 50.
  • 3. The process of claim 1 wherein R is the organic cation derived from ethylenediamine.
  • 4. The process of claim 1 wherein R is the organic cation derived from pyrrolidine.
  • 5. The process of claim 1 wherein the catalyst has its original cations replaced, at least in part, by ion exchange with a cation or a mixture of cations selected from the group consisting of hydrogen and hydrogen precursors, rare earth metals, and metals from Groups IIA, IIIA, IVA, IB, IIB, IIIB, IVB, VIB and VIII of the Periodic Table of Elements.
  • 6. The process of claim 5 wherein said catalyst has its original cations replaced, at least in part, by ion exchange with hydrogen or hydrogen precursor cations.
  • 7. The process of claim 5 wherein said catalyst has its original cations replaced, at least in part, by ion exchange with rare earth metal cations.
  • 8. The process of claim 1 wherein said catalyst conversion is conducted in a flow apparatus and said conversion conditions include a temperature of from about 100.degree. F to about 1,200.degree. F, a pressure of from about atmospheric to about 10,000 psig, a hydrogen/hydrocarbon compound ratio of from 0 to about 20,000 scf/bbl and a liquid hourly space velocity of from about 0.1 hr.sup.-1 to about 50 hr.sup.-1.
  • 9. The process of claim 1 wherein said catalytic conversion is conducted in a batch apparatus and said conversion conditions include a temperature of from about 100.degree. F to about 1,200.degree. F, pressure of from about atmospheric to about 10,000 psig, a hydrogen/hydrocarbon compound ratio of from 0 to about 20,000 scf/bbl and a contact time of from about 0.01 hour to about 48 hours.
  • 10. The process of claim 8 wherein said conversion is aromatization of paraffins and said conversion conditions include a temperature of from about 600.degree. F to about 1,200.degree. F, a pressure of from about 50 psig to about 10,000 psig, a hydrogen/hydrocarbon ratio of from about 50 scf/bbl to about 10,000 scf/bbl and a liquid hourly space velocity of from about 0.1 hr.sup.-1 to about 10 hr.sup.-1.
  • 11. The process of claim 9 wherein said conversion is aromatization of paraffins and said conversion conditions include a temperature of from about 600.degree. F to about 1,200.degree. F, a pressure of from about 50 psig to about 10,000 psig, a hydrogen/hydrocarbon ratio of from about 50 scf/bbl to about 10,000 scf/bbl and a contact time of from about 0.1 hour to about 48 hours.
  • 12. The process of claim 8 wherein said conversion is cracking and said conversion conditions include a temperature of from about 700.degree. F to about 1,200.degree. F, a pressure of from about atmospheric to about 200 psig and a liquid hourly space velocity of from about 0.5 hr.sup.-1 to about 50 hr.sup.-1.
  • 13. The process of claim 9 wherein said conversion is cracking and said conversion conditions include a temperature of from about 700.degree. F to about 1,200.degree. F, a pressure of from about atmospheric to about 200 psig and a contact time of from about 0.01 hour to about 24 hours.
CROSS-REFERENCE TO RELATED APPLICATIONS =

This is a continuation-in-part of application Ser. No. 528,061, filed November 29, 1974, now U.S. Pat. No. 4,016,245, which was a continuation-in-part of application Ser. No. 393,767, filed September 4, 1973, now abandoned, which was a continuation-in-part of application Ser. No. 358,192, filed May 7, 1973, now abandoned.

US Referenced Citations (11)
Number Name Date Kind
3687839 Jenkins Aug 1972
3700585 Chen et al. Oct 1972
3748251 Demmel et al. Jul 1973
3783124 Rubin et al. Jan 1974
3790474 Argauer et al. Feb 1974
3804746 Chu Apr 1974
3843741 Yan Oct 1974
3923639 Ciric Feb 1975
3960973 Givens et al. Jan 1976
3968024 Gorring Jul 1976
3970544 Rosinski et al. Jul 1976
Non-Patent Literature Citations (3)
Entry
Barrer et al., "Chemical Society Journal," 1964, Part 1, pp. 485-497.
Barrer et al., "The American Mineralogist," 50, pp. 484-489 (1965).
Wise, "The Am. Mineralogist," 54, 887-895 (1969).
Continuation in Parts (3)
Number Date Country
Parent 528061 Nov 1974
Parent 393767 Sep 1973
Parent 358192 May 1973