GB1589856A - Zeolite z5m-34 and conversion thereover - Google Patents

Description

(54) ZEOLITE ZSM-34 AND CONVERSION THEREOVER (71) We, MOBIL OIL CORPORATION, a Corporation organised under the laws of the State of New York, United States of America, of 150 East 42nd Street, New York, New York 10017, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a crystalline aluminosilicate zeolite, to methods for its preparation, and to its use as a catalyst in a variety of organic compound conversions.

Known zeolites, sometimes referred to as "molecular sieves", include a wide variety of positive ion-containing crystalline aluminosilicates, both natural and synthetic. Among the synthetic zeolites are those known as A, Y, L, D, R, S, T, Z, E, F, Q, B, X; erionite and offretite are well-known natural zeolites. All can be generally described as having a rigid 3-dimensional network of SiO4 and A104 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 atoms is 1:2. The electrovalence of the tetrahedra containing aluminum is negatively charged and the composition is balanced by the inclusion in the crystal structure of a cation, for example, an alkali metal or an alkaline earth metal cation. The spaces between the tetrahedra are occupied by molecules of water prior to dehydration: it is customary to dehydrate zeolites prior to using them as sorbents or catalysts.

According to the present invention a new crystalline alumino-silicate zeolite, known as ZSM-34, has the composition, in terms of mole ratios or oxides; M2O : Awl203: (8-50) SiO2 Th in which M represents a cation of valence n, possesses an X-ray powder diffraction pattern substantially as set forth in Table 1 herein and is capable, after calcination at 10000F for at least a period of time sufficient to remove any organic cation, of sorbing at least 9.5 weight percent of n-hexane at ambient temperature and a n-hexane pressure of 20 mm. The mole ratio SiO2/Al2OS is preferably 8 to 30, still more preferably 8 to 20. Like all zeolites, ZSM-34 can exist in a wide variety of cationic forms, preferred forms being those wherein M comprises ammonium, hydrogen, rare earth metal, aluminum, manganese or metal of Group II or VIII of the Periodic Table. By contrast, in the anhydrous, as-synthesized form the zeolite usually has the chemical analysis, in terms of mole ratios of oxides: (0.5-1.3) R2O: (0-0.15) Na2O: (0.1-0.5) K2O: Al203: (8-50) SiO2 in which R is an organic nitrogen-containing cation derived from choline. It will be appreciated that the formula furnished for the as-synthesised form of the zeolite provides for cation: aluminum equivalence greater than the unity demanded by structural considerations. This is because chemical analysis of as-synthesised zeolites rarely reveals the perfect cation: aluminum equivalence, particularly when nitrogenous cations play a part in synthesis: the general formula first presented herein, in which cations are identified by the symbol M, is on the other hand the ideal formula.

According to another aspect of the invention a method of preparing a crystalline aluminosilicate zeolite comprises forming a mixture containing sodium oxide, potassium oxide, silica, alumina, a choline compound and water and having a composition, in terms of mole ratios of oxides, falling within the following ranges: SiO2/Al2O3 ------------------------------------------------------------- 10 - 70 OH-/SiO2 ------------------------------------------------------------ 0.3 - 1.0 H2O/OH- ------------------------------------------------------------- 20 - 100 K2O/X2O ------------------------------------------------------------- 0.1 - 1.0 R+/R+ + X+ ---------------------------------------------------------- 0.1 - 0.8 where R+ is choline and X is sodium + potassium, and maintaining the mixture at a temperature between 80 C and 175 C until crystals of said zeolite are formed. The mixture advantageously has a composition falling within the following ranges: SiO2/Al2O3 ------------------------------------------------------------- 10 - 55 OH-/SiO2 ------------------------------------------------------------ 0.3 - 0.8 H2O/OH- -------------------------------------------------------------- 20 - 80 K2O/X2O ------------------------------------------------------------- 0.1 - 1.0 R+/R+ + X+ ------------------------------------------------------- 0.1 - 0.50 The invention further comprehends a process for converting an organic charge which comprises contacting said charge, under conversion conditions, with a catalyst comprising zeolite ZSM-34. conversions particularly effectively accomplished with respect to hydrocarbon charges include cracking and polymerisation.

A particularly effective conversion of non-hydrocarbon charge comprises the conversion of methanol and/or dimethyl ether to a hydrocarbon product rich in ethylene and propylene, the conversion conditions comprising a temperature between 500 F and 1000 F, a pressure from 0.1 to 30 atmospheres and a weight hourly space velocity between 0.1 and 3(). According to this embodiment, ethylene and propylene can constitute the major proportion of the hydrocarbon reaction product, the ethylene content of the product often exceeding the propylene content. Typically, the amount of ethylene and propylene produced exceeds 35 weight percent, and the amount of methane produced is not more than 10 weight percent, of the hydrocarbon reaction product.

Whatever the nature of the conversion, the zeolite is preferably thermally treated before use at a temperature of 200 C to 750 C, and at least 10 percent of its cation sites are preferably satisfied by ions other than alkaly or alkaline earth metals. Suitable replacing cations comprise hydrogen, cations convertible to hydrogen, metals from Groups, IB, II, Ill, VIIB, VIII or rare earth metals, with hydrogen and/or rare earth particularly preferred. advantageously the catalyst may be a composite of the zeolite with a porous matrix. In some applications, moreover, the zeolite will benefit from prior steam treatment for 1 to 100 hours at 700 to 12()()0F.

ZSM-34 is similar in some respects to offretite or erionite but is distinguished from these zeolites in its capability, after calcination at 10000F for at least a period of time sufficient to remove any organic cation to sorb at least 9.5 weight percent of normal hexane, at ambient temperature and n-hexane pressure of 20 mm. which is higher than that of any known member of the offretite-erionite family. ZSM-34 is further characterized by an apparent tubular morphology, and its X-ray diffraction pattern shows the following characteristic lines: TABLE 1 Relative 20 D( ) Intensity 7.68 11.5 + .2 VS 9.62 9.2 t .2 W 11.67 7.58 + .15 M 13.39 6.61 + .13 S 14.01 6.32 i .12 W 15.46 5.73 + .11 M 16.57 5.35 + .10 W 17.81 4.98 1 .10 W 19.42 4.57 + .09 S-VS 20.56 4.32 + .08 VS 21.36 4.16 + .08 W 23.35 3.81 + .07 S-VS 23.79 3.74 + .07 VS 24.80 3.59 + .07 S-VS 27.02 3.30 + .06 M-S 28.33 3.15 + .06 M 30.62 2.92 + .05 W 31.41 2.85 + .05 VS 31.93 2.80 + .05 W 33.50 2.67 + .05 W 35.68 2.52 + .05 W 36.15 2.48 + .05 W-M 38.30 2.35 + .04 W 39.49 2.28 + .04 W 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 position as a function of 2 times theta, where theta is the Bragg angle were read from the spectrometer chart. From these, the relative intensities, 100I/Io, where lo is the intensity of the strongest line or peak and d (obs.), the interplanar spacing in A, corresponding to the recording lines were calculated.

The intensity in the table above is expressed as follows: Relative Intensity 100 1/leo VS (Very Strong) 60 - 100 S (Strong) 40 - 60 M (Medium) 20 - 40 W (Weak) 0 - 20 ZSM-34 displays "1" odd lines not to be expected if it has the open offretite structure.

These "1" odd lines (observed at about 9.6, 16.6, 21.4 and 31.9 20) are broad in contrast to sharp ones in erionite. Without being limited by any theory, these data may be taken to indicate that ZSM-34 is not a physical mixture of offretite and erionite but rather an intergrowth of very small erionite domains throughout an offretite structure. These erionite domains appear as stacking faults and may contribute blockages to the main offretite channel.

Zeolite T has been reported by Bennett and Gard, Nature 214, 1005 (1967) to be a disordered intergrowth of erionite and offretite. Although the X-ray diffraction pattern of ZSM-34 indicates it to be an offretite with erionite intergrowth, ZSM-34 is unlike Zeolite T.

As shown in Table 2 below ZSM-34 displays a line at 14.010 20 and the "1" odd lines at about 16.62 and 31.92 20 which are missing in Zeolite T. The latter zeolite, on the other hand, has some weak lines at about 14.74, 21.78, 24.28 20 as well as a doublet at about 31.2 20.

A comparison of the X-ray diffraction pattern of ZSM-34, offretite, erionite and Zeolite T is shown below: TABLE 2 ZSM-34 Offretite a 20 I/Io 20 +A0 I/Io min.-max.

7.65 100 7.70 .12 99 90-100 9.60 broad 3 11.65 25 11.75 .08 39 0- 85 13.37 52 13.38 .15 67 29-100 14.01 10 14.06 .07 31 0- 55 15.45 31 15.46 .16 30 15- 55 16.62 broad 4 17.82 10 17.77 - 10 0- 10 19.40 64 19.49 .11 42 0- 85 2().5() 61 20.50 .17 69 43- 90 21.35 broad 7 - - - - - - 23.13 .05 54 0- 65 23.31 55 23.40 .09 46 0- 85 23.67 86 23.75 .18 83 0-100 24.77 86 24.88 .15 62 3-100 - - 26.24 .26 5 0- 10 27.03 34 26.98 .27 36 19- 55 - - 27.31 .10 18 0- 55 - - 28.16 .29 18 5- 55 28.25 40 28.44 .07 47 0- 60 - - - 30:55 9 30.58 .20 11 0- 25 - - 31.00 .05 68 0- 71 31.35 84 31.31 .14 44 12- 80 - - 31.57 .07 73 0- 85 31.92 11 33.45 16 33.48 .34 23 3- 55 35.70 4 35.79 .19 14 5- 31 36.1() 21 36.06 .06 8 0- 10 - - 36.29 .08 25 0- 55 TABLE 2 Continued Erioniteb Linde T 20 lAO I/Io min.-max. 20 I/Io 7.72 .10 83 5-100 7.72 100 9.69 .14 38 0-100 9.63 4 11.73 .34 25 3- 85 11.74 13 13.41 .17 69 38-100 13.35 54 14.02 .14 19 0- 55 - 14.74 2 15.49 .13 22 0- 55 15.44 6 16.57 .12 21 7- 55 17.79 .16 12 0- 25 17.78 2 19.46 .22 29 0- 85 19.43 8 20.54 .16 60 0- 90 20.46 45 21.37 .17 34 10- 85 21.35 3 21.78 2 23.35 .13 48 14- 90 23.27 16 23.75 .21 64 0-100 23.64 56 24.36 .23 20 0- 45 24.28 1 24.87 .07 47 0-100 24.80 30 26.24 .13 9 1- 25 26.04 2 26.99 .14 32 17- 55 26.92 16 27.26 .27 25 0- 55 28.15 .11 18 0- 38 28.04 12 28.36 .06 34 0- 55 28.29 18 28.79 .20 10 0- 25 30.54 .28 17 0- 55 30.47 11 31.15 38 31.26 .10 41 0- 75 31.38 45 31.54 .13 61 0-100 31.92 .15 39 0- 85 33.54 .20 28 0- 85 33.41 11 34.71 .17 15 0- 25 34.32 2 35.80 .06 18 0- 30 35.83 8 35.98 .06 30 0- 70 36.09 13 36.22 .07 24 0- 55 a Average of eight offretites in the literature b Average of eleven erionites in the literature The equilibrium adsorption characteristics of ZSM-34 are compared to members of the offretite-erionite family in Table 3 below.

TABLE 3 Sample H2O n-Hexane Cyclohexane Wt. % cc/g Wt. % cc/g Wt. % cc/g ZSM-34 20.1 0.20 10.7 0.16 4.3 0.06 Synthetic Offretite 16.5 0.16 8.8 0.13 7.8 0.10 14.8 0.15 7.9 0.12 2.9 0.04 Synthetic Erionite 18.0 0.18 6.5 0.10 1.0 0.01 Natural Erionite 15.6 0.16 5.3 0.08 0.9 0.01 Zeolite T 18.2 0.18 (6.6 0.11)* 0.8 0.01 Values in brackets are for n-pentane.

The above adsorption data were determined as follows: A weighed sample of the zeolite was contacted with the desired pure adsorbate vapor in the adsorption chamber at a pressure less than the vapor - liquid equilibrium pressure of the adsorbate at ambient temperature, e.g. about 25"C. This pressure was kept constant during the adsorption period, which did not exceled about 8 hours. Adsorption was complete when a constant pressure in the adsorption chamber was reached, i.e., 12 mm. of mercury for water and 20 mm. for n-hexane and cyclohexane. The increase in weight was calculated as the adsorption capacity of the sample.

It will be evident from the above tabulated data that ZSM-34 was characterized by the highest sorptive capacity for water and n-hexane. It is a unique property of ZSM-34 that this zeolite, in contrast to other known members of the offretite-erionite family, has the capability of sorbing at least 9.5 weight percent of n-hexane.

The original cations of the ZSM-34 can be replaced in accordance with techniques well-known in the art, at least in part, by ion exchange with other cations preferably after calcination. Preferred replacing cations include tetraalkylammonium cations, metal ions, aluminium ions, hydrogen ions, and mixtures of the same. Particularly preferred cations are those which render the zeolite catalytically active, especially for hydrogen conversion.

These include hydrogen, rare earth metals, aluminum, manganese, and metals of Groups II and Vill of the Periodic Table.

ZSM-34 can be suitably synthesized by preparing a gel reaction mixture having a composition, in terms of mole ratios of oxides, falling within the following ranges: Broad Preferred SiO2/Al2O3 10-70 10-55 Oll/SiO2 0.3-1.0 0.3-0.8 H,O/OH- 20-100 20-80 K2O/X2O 0.1-1.0 0.1-1.0 R+/R+ + X+ 0.1-0.8 0.1-0.50 where R+ is choline [(Cll3)3.N-CH2CH2OllJ+ and X is Na + K and maintaining the mixture until crystals of the zeolite are formed. OH- is calculated from inorganic base not ncutrnlized by any added mineral acid or acid salt. Resulting zeolite crystals are separated and recovered. Typical reaction conditions consist of heating the foregoing reaction mixture to a temperature of from 80"C to 175"C for a period of time of from 12 hours to 200 days. A more preferred temperature range is from 90 to 1600C with the amount of time at a temperature in such range being from 12 hours to 50 days.

The resulting crystalline product is separated from the mother liquor by filtration, water washing and drying, e.g., at 230 F for from 4 to 48 hours. Milder conditions may be employed, if desired, e.g., room temperature under vacuum.

ZSM-34, when employed either as an adsorbent or as a catalyst in a hydrocarbon conversion process should be at least partially dehydrated and the organic cation at least partially removed. This can be done by heating to a temperature in the range of 200 to 75() C in an atmosphere, such as air, nitrogen, etc., and at atmospheric or subatmospheric pressure for between 1 to 48 hours. Dehydration can also be preferred at lower temperatures merely by placing the catalyst in a vacuum, but a longer time is required to obtain a sufficient amount of dehydration.

The composition of ZSM-34 can be prepared utilizing materials which supply the appflpriate oxide. Such compositions include, for example. sodium aluminate, alumina, sodium silicate, silica hydrosol, silica gel, silicic acid, sodium hydroxide, aluminum sulfate, potassium hydroxidc, potassium silicate. and a choline compound such as the halide, i.e. fluoridc, chloride or bromide; sulfate. acetate; or nitrate. It will be understood that each oxide component utilized in the reaction mixture for preparing ZSM-34 can be supplied by one or more initial rcactants and they can be mixed together in any order. The reaction mixture can be prepared either batchwise or continuously. Crystal size and crystallization time of the ZSM-34 composition will vary with the nature of the reaction mixture employed.

In many instances, it is desired to incorporate the ZSM-34 with another material resistant to the temperature and other conditions employed in organic conversion processes. 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. 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 ZSM-34, i.e., combined therewith which is active, tends to improve the conversion and/or selectivity of the catalyst in certain organic conversion processes. lnactive materials suitably serve as diluents to control the amount of conversion in a given process so that products can be obtained economically and in orderly manner without employing other means for controlling the rate of reaction. Normally, zeolitic materials have been incorporated into naturally occurring clays. e.g. bentonite and kaolin, to improve the crush strength of the catalyst under commercial operating conditions. These materials, i.e., clays, oxides and the like function 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. These clay binders have been employed for the purpose of improving the crush strength of the catalyst.

Naturally occurring clays which can be composited with the ZSM-34 catalyst include the montmorillonite and kaolin family, which families include the sub-bentonites and the kaolins commonly known as Dixie, McNamee-Georgia and Florida clays or others in which the main mineral constituent is halloysite, kaolinite, dickite, nacrite or anauxite. Such clays can be used in the raw state as originally mined or initially subjected to calcination, acid treatment or chemical modification.

In addition to the above materials, ZSM-34 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-aluminazirconia, silica-alumina-magnesia, and silica-magnesia-zirconia. The matrix can be in the form of a cogel. The relative proportion of finely divided ZSM-34 and inorganic oxide gel matrix may vary widely with the crystalline aluminosilicate content ranging from 1 to 90 percent by weight and more usually in the range of 2 to 50 percent by weight of the composition.

As noted hereinabove, ZSM-34 is useful as a catalyst in organic compound conversion.

Representative hydrocarbon conversion processes are cracking, hydrocracking or alkylation of hydrocarbons; isomerization of n-paraffins and naphthenes; polymerization of compounds containing an olefinic or acetylenic carbon-to-carbon linkage such as propylene, isobutylene and butene-1; reforming or isomerization of polyalkyl substituted aromatics, e.g., ortho xylene; and disproportionation of aromatics, such as toluene, to provide a mixture of benzene, xylenes, and higher methylbenzenes. The ZSM-34 catalysts are characterized by high selectivity, under the conditions of hydrocarbon conversion, to provide a high percentage of desired products.

ZSM-34 is generally used in the ammonium, hydrogen or other univalent or multivalent cationic form. It can also be used in intimate combination with a hydrogenation component such as tungsten, vanadium, molybdenum, rhenium, nickel, cobalt, chromium, manganese or a noble metal, such as platinum or palladium when a hydrogenation-dehydrogenation function is to be performed. Such component may be exchanged into the zeolite, impregnated thereon or physically intimately admixed therewith.

Employing the ZSM-34 catalyst of the invention for cracking, hydrocarbon charge stocks can be cracked at a liquid hourly space velocity between 0.5 and 50, a temperature between 550"F and 1100 F, and a pressure between atmospheric and several hundred atmospheres.

When used for polymerization of olefins, the temperature is generally between 550"F and 850"F, utilizing a weight hourly space velocity between 0.1 and 30 and a pressure between 0.1 and 50 atmospheres.

In accordance with a particularly favoured embodiment of the present invention, it has been found that use of ZSM-34 as catalyst affords a substantially higher selectivity for ethylene and for propylene production from methanol and/or dimethyl ether over corresponding use of other crystalline aluminosilicate zeolites. It has further been found utilizing the specified crystalline aluminosilicate zeolite catalyst described herein that the C2-C3 olefin content of the reaction product obtained can be in excess of 35 weight percent and preferably constitute a major proportion of such reaction product. The latter is substantially devoid of aromatic hydrocarbon content and contains, as a result of employing the specified catalyst, less than 20 weight percent, and preferably not more than 10 weight percent, of methane.

The methanol feedstock may be manufactured from synthesis gas, i.e., a mixture of CO and H2, from coal or may be produced by fermentation.

The ZSM-34 employed in this embodiment preferably has at least 10 percent of the cationic sites thereof occupied by ions other than alkali or alkaline earth metals.

Replacement of the original ions is generally accomplished by ion exchange, preferably after calcination. Typical but non-limiting replacing ions include ammonium, hydrogen, rare earth, zinc, copper, nickel and aluminum. Of this group, particular preference is accorded ammonium, hydrogen, rare earth or combinations thereof. In a preferred embodiment, the zeolites are converted to the predominantly hydrogen form, generally by replacement of the alkali metal or other ion originally present with hydrogen ion precursors, e.g. ammonium ions, which upon calcination yield the hydrogen form. This exchange is conveniently carried out by contact of the zeolite with an ammonium salt solution, e.g., ammonium chloride, utilizing well known ion exchange techniques. The extent of replacement is such as to produce a zeolite material in which at least 50 percent of the cationic sites are occupied by hydrogen ions.

In some instances, it has been found desirable to subject the ion-exchanged zeolite to steam treatment for 1 to 100 hours at a temperature above 700 F but less than 1200 F.

Methyl alcohol and/or dimethyl ether conversion is typically carried out in the vapor phase by contact in a reaction zone, such as for example, a fixed bed of catalyst, under effective conversion conditions. Such conditions include an operating temperature between 500"F, and l0000F, a pressure between 0.1 and 30 atmospheres and preferably atmospheric pressure and a weight hourly space velocity between 0.1 and 30 and preferably between 1 and 1(). Carrier gases or diluents may be injected into the reaction zone such as, for example, hydrogen, carbon monoxide, carbon dioxide or nitrogen.

The methyl alcohol and/or dimethyl ether conversion process described herein may be carried out as a batch-type semi-continuous or continuous operation utilizing a fixed, fluidized or moving bed catalyst system. A preferred embodiment entails the use of a catalyst zone wherein the alcohol or ether charge is passed concurrently or countercurrently through a moving or fluidized bed of particle-form catalyst. The latter after use is conducted to a regeneration zone wherein coke is burned from the catalyst in an oxygen-containing atmosphere, e.g., air, at an elevated temperature, after which the regenerated catalyst is recycled to the conversion zone for further contact with the alcohol and/or ether feed.

The product stream in the process of the invention contains steam and a hydrocarbon mixture of paraffins and olefins, substantially devoid of aromatics. This mixture is particularly rich in light olefins, i.e., ethylene and propylene. Generally, a major fraction of the total olefins is ethylene plus propylene, with the ethylene content of the product exceeding the propylene content. Thus, the predominant hydrocarbon product constitutes valuable petrochemicals. The steam and hydrocarbon products may be separated from one another by methods well known in the art.

The following examples will serve to illustrate synthesis and use of the new crystalline aluminosilicate described hereinabove. Where a mesh is mentioned in these examples, it relates to the Tyler standard.

Example 1 4.43 grams of KOH (86.4%), 13 grams of NaOH (96%) and 5.74 grams of sodium aluminate (43.107ho Alloy, 33.1% Na2O, 24% H2O) were dissolved in 90 grams of water.

Choline chloride (38 grams) was added to the resulting solution, followed by the addition of 130 grams of colloidal silica (30 Wt.% SiO2 and 70 Wt.% H2O). A gel formed having the following molar composition: SiO2/Al2O3 = 26.6 R+ = 0.38 R+ + X+ OH = 0.68 SiO2 1120 = 22.9 OH K2O = - 0.15 x2O where R+ is choline ((C113)3NCFl2CH2OH]+ and X is Na + K.

The resulting gel was mixed for 15 minutes and allowed to crystallize in a polypropylene container at 2100F for 25 days. The crystalline product obtained was separated from the mother liquor by filtration, water washed and dried at 2300F. This product, upon analysis, was found to have the following composition molar ratio: 0.64 R2O: 0.47K2O: 0.13 Na2O: Awl203: 10.8 SiO2 and the following X-ray diffraction pattern: 20 D(A) Intensity 7.65 11.56 100 9.60 9.21 3 11.65 7.60 25 13.37 6.62 52 14.01 6.32 10 15.45 5.74 31 16.62 5.33 4 17.82 4.98 10 19.40 4.58 64 20.50 4.33 61 21.35 4.16 7 23.31 3.82 55 23.67 3.76 86 24.77 3.59 86 27.03 3.30 34 28.25 3.16 40 30.55 2.926 9 31.35 2.853 84 31.92 2.804 11 33.45 2.679 16 35.70 2.515 4 36.10 2.488 21 39.41 2.286 4 41.02 2.200 7 42.90 2.108 6 43.50 2.080 4 45.75 1.983 4 46.42 1.956 3 48.15 1.890 19 48.83 1.865 5 49.84 1.830 6 A portion of the product of Example 1, calcined at 1000"F for 16 hours, had the following sorption and surface area properties: Sorption Wt.% Cyclohexane = 4.4 n-Hexane = 11.5 Water = 22.2 Surface area m2/g = 523 Examples 2 - 7 These examples were carried out in a manner similar to that of Example 1 and had substantially the same X-ray diffraction pattern. The composition of the gel obtained and the product composition, together with adsorption properties and surface area are shown below in Table 4.

TABLE 4 Example 2 3 4 5 6 7 Gel Molar Ratio SiO2/Al2O3 13.4 13.4 26.8 26.8 26.8 26.8 R+(1)/R+ + X+ (2) 0.47 0.47 0.47 0.31 0.50 0.47 OH-/SiO2 0.48 0.47 0.48 0.48 0.42 0.48 HO/OH- 32.2 32.8 32.5 32.5 37.0 32.5 K2O/X2O 0.22 0.22 0.22 0.22 0.11 0.22 Crystallization Days at 2100F 35 32 25 135 196 48 X-Ray Analysis ZSM-34 ZSM-34 ZSM-34 ZSM-34(3) ZSM-34(3) ZSM-34 Product Composition (Molar Ratio) Al203 1.0 1.0 1.0 1.0 1.0 1.0 SiO2 9.8 10.2 13.3 15.0 17.8 13.9 Na2O 0.14 0.07 0.12 0.12 0.16 0.02 K2O 0.40 0.36 0.27 0.21 0.11 0.22 R2O 0.66 0.67 0.57 1.02 1.21 0.94 Adsorption, wt % (calcined 16 hrs at 1000 F) Cy-C" 4.3 4.9 5.2 5.2 4.4 6.4 N-C6 10.7 10.3 11.2 11.3 10.3 11.3 H2O 20.1 20.9 19.0 18.9 16.2 15.9 Surface Area, m2/g 532 524 521 536 502 520 (1) R+ = [(CH3)3N-CH2CH2OH] (2) X+ = Na+ + K+ (3) Possibly contains some Levvnite.

Example 8 ZSM-34 can also be synthesized from mixtures containing aluminum sulfate and sodium silicate. Utilizing these reactants, a solution containing 15.98 grams of Al2(SO4)3.18 H2O in 100 grams of water was added to a solution of 135.4 grams of Q-Brand sodium silicate (22.8% SiO2, 8.9% Na2O and 62% H2O) and 40 grams of water to which 4.4 grams of KOH (86.4%) and 38 grams of choline chloride had been added. A gel formed having the following molar com Example 9 ZSM-34 can also be synthesized from potassium silicate. Utilizing this reactant, a solution of aluminum sulfate containing 15.98 grams of Al2(SO4)3 18 H2O and 4.4 grams of H2SO4 in 100 grams of water was added to a solution of 187.5 grams of potassium silicate (20.8% SiO2, 8.3%K2O and 72.9% H2), 0.2 gram of quercetin and 20 grams of water. Thereafter, 9.6 grams of NaOH and 38 grams of choline chloride were added.

A gel formed having the following composition: SiO/Al2O3 = 27.2 R+ = 0.44 R+ + M+ OH = - 0.52 SiO2 H20 = - 40.4 OH K20 = - 0.97 M20 This gel, after mixing for 15 minutes, was heated at 210 F for 73 days. After filtration, the product was water washed and dried at 230 C. Upon analysis, the product was found to be ZSM-34 having the following molar composition: 0.94 R2O: 0.4 K2O: 0.02 Na2O: Al203: 14.5 SiO2 After calcination, this product had the following sorptive and surface area properties: Sorption Wt. % Cyclohexane = 5.3 n-Hexane = 10.7 Water = 17.8 Surface Area m2/g = 499 Example 10 ZSM-34 was prepared by mixing together the following solutions: A. Caustic Aluminate 69.89 grams sodium aluminate (20% Na, 43.10/n Al203 and balance H2O) 29.28 grams NaOH (77.5 wt. % Na2O) 26.4 grams KOH (86.4% KOH) 540 grams H2O B. Silica Solution 780 grams Colloidal silica sol. (30% SiO2).

C. Cholille Chloride 228 grams Solution C was added to Solution A in a 2 liter autoclave with mixing and then Solution B was added, followed by a 15 minute continuous mixing. The autoclave was then sealed and heated to and held at 3()() F for 8 days. The contents were stirred continuously during the 8 days crystallization period.

The autoclave and its contents were then cooled to room temperature, filtered and washed to separate the crystalline product from the reaction mixture.

On analysis, the resulting product was established by X-ray diffraction pattern to be ZSM-34 containing: Wt. % Na 0.68 K 3.59 Al203 13.5 SiO2 78.5 N 2.0 This product had the following molar composition: 0.54 R2O: 0.11 Na2O: 0.35 K2O: Awl203: 9.87 SiO2.

Adsorption and surface area properties were as follows: Sorption Wt. % Cyclohexane = 3.5 n-Hexane = 9.6 Water = 19.7 Surface Area m2/g 448 Example 11 This example was carried out in the same manner as that of Example 10 except the reaction temperature was reduced to 250"F and the reaction time extended to 11 days.

The resulting product had the following molar composition: 0.52 R2O: 0.159 Na2O: 0.34 K2O: Awl203: 9.65 SiO2 and a surface area of 512 m2/gram.

Example 12 A sample of ZSM-34, prepared as in Example 7, was ion exchanged by treatment with a 10 weight percent aqueous solution of ammonium chloride by contacting 5 times for 1 hour each contact at 1850F and thereafter calcining in air for 10 hours at 1000"F to yield the hydrogen form of the zeolite.

Catalytic cracking of n-hexane was carried out using the resulting exchanged ZSM-34 as catalyst, by means of an alpha test which is described in the Journal of Catalysis Vol IV, No.

4, August 1965. pages 527-529.

In the test 0.5cc of catalyst sized 14 to 25 (Tyler) mesh was contacted with n-hexane at a vapor pressure of 110 mm. The test was run at 700"F with products analyzed after 5 minutes of run, giving 21.3 wt. % conversion. The calculated a value or relative activity for cracking n-hexane compared to standard silica-alumina was 877.

Example 13 Cracking with NH4+ exchanged ZSM-34 prepared as in Example 6 was evaluated as described under Example 12 but at 8000F giving 22.1 wt. % conversion after 5 minutes which calculates to an a value of 163.

Example 14 Propylene polymerization with the hydrogen form of ZSM-34 prepared as in Example 6 was run as described below.

Propylene was passed over a calcined 2.6cc (1.0348 g) sample of ZSM-34 catalyst contained in a tubular glass reactor equipped with an axial thermowell at atmospheric pressure. The catalyst was preheated in air flowing in lOce/minute at 1000"F for 1.25 hour and then purged with helium, while the reactor temperature lined out at 6000F.

The reactor effluent was collected between the 1 and 2 hours on stream and was analyzed. At these conditions of 1.3 WHSV, 600"F, 81.7 wt. % of the propylene was converted based on recovered products. On the basis of converted products, the yield was 96.6 wt. % C4+ and 83.7 wt. % C5+.

Evaluating the same catalyst at 7.9 WHSV and 600"F gave a 34.2 wt. % conversion of the propylene with a yield based on converted products of 97.5 wt. % C4+ and 90.6 wt. % Cg+ At a 8.4 WHSV and 700 F the conversion was 52 wt. % with a yield of 82.5 wt. % C5+ based on converted products.

Example 15 Cracking with a calcined NH4+ exchanged ZSM-34 prepared as in Example 5 was evaluated as described under Example 12 but at 800 F giving 27 wt % conversion after 5 minutes which calculates to an a value of 205.

Example 16 Propylene polymerization with the hydrogen from ZSM-34, prepared as in Example 15, was evaluated as described under Example 14. Here 0.67cc (0.25g) catalyst at 600 F was contacted with the propylene. At these conditions 7.9 WHSV, 600 F, 31.6 wt. % was converted and on the basis of converted products the yield was 96.8 wt. % C4+ and 88.1 wt.

% C5+. Another run employing 2.5 cc (1.0249 g) catalyst at 600 F at these conditions of 1.3 WHSV, 76.1 wt. % of the propylene charge was converted to yield 96 wt. % C4+ and 83 wt.

% C5+ based on converted products.

Example 17 Cracking with NH4+ exchanged ZSM-34 prepared as in Example 3 was evaluated as described under Example 12 at 800 F. The conversion was 38.9 after 5 minutes which calculates to an (x value of 322.

Example 18 Propylene polymerization with the hydrogen form of ZSM-34, prepared as in Example 17 was evaluated as described under Example 14.

In evaluating this example 0.6cc (0.2535 g) was used and evaluated at 6000F at these conditions of 7.7 WHSV and 600 F 40.1 wt. % of the propylene, on recovered basis, was converted yiclding 97.1 wt. % C4+ and 86.8 wt. % CS+ based on converted products.

Example 19 A sample of the product of Example 3 was processed by calcining for 10 hours at 10000F and exchange with a 1() wt % NH4Cl solution at 1850F employing 5 one hour contacts. After the final contact the exchanged product was filtered, water washed, dried at 230 F, pelleted and sized 14-25 mesh and calcined for 10 hours at 10000F in air.

Example 20 Methanol at a flow rate of 3.85 ml/hr was passed over 1.0 gram of the ion exchanged catalyst product of Example 19 at atmospheric pressure and a nominal 700 F. The catalyst bed had an axial bed length of 23/8 inches. The catalyst was pretreated in place with an air flow of 10 cc/min at 1()0() F for one hour followed by a 10 minute nitrogen purge of 10 cc/min while the reactor temperature dropped to 700 F. When methanol was passed over the bed, the temperature profile of the bed changed as shown in Table 2 after 2 hours on stream. The effluent stream from the reactor was collected between 1 and 2 hours on stream. Run conditions and product analysis are shown in Table 3. In this example, 87.9% of the methanol was converted of which 21c4 went to an oxygen-free hydrocarbon product.

This product was 5().96X" ethylene and 27.3SG propylene.

Example 21 Dimethyl ether (DME) was passed over 1.0 gram of the ion exchanged catalyst product of Example 19 at a rate of 2.0 liters per hour at a nominal 70()0F. The catalyst bed had an axial bed length of 27/1(, inches. The catalyst was pretreated in place with an air flow of 10 cc/min at 1000 F for one hour followed by a 10 min. nitrogen purge during which the temperature dropped to 700 F. DME was then passed over the bed. The temperature profiles of the catalyst bed after 2 and 6 hours on stream are shown in Table 2. The effluent stream from the reactor was collected between 1 and 2 hours and between 5 and 6 hours on stream. The run conditions and product analysis are shown in Table 3. Between 1 and 2 hours on stream, 39.5% of the charged DME was converted of which 54.2% went to hydrocarbons (oxygen-free). Ethylene was 22.0% of the hydrocarbon phase and propylene was 15.3%.

L;xas71ple 22 The catalyst used in Example 21 was calcined in situ for 16 hours to burn off residual carbon at 1000 F in an air flow of 1() cc/min. The bed was purged with nitrogen at a flow of 10 cc/min for 10 minutes while the temperature dropped to 700 F. Methanol at a rate of 4.0 ml/hr was passed over the bed at a nominal 7000F. The temperature profiles (Table 5) of the bed were taken at 2 and 5.5 hours on stream. The effluent stream from the reactor was collected between 1 and 2 hours and 4.5 and 5.5 hours on stream. The run conditions and product analyses are shown in Table 6.

Example 23 Methanol at a flow rate of 3.75 ml/hr was passed over 1.0 gram of the ion exchanged catalyst product of Example 19 which had been steamed for 20 hours at 9000F. The catalyst at a nominal 700"F and atmospheric pressure was contained in a reactor with an axial bed length of 21/4 inches. The catalyst was pretreated in place with an air flow of 10 cc/min at 1000"F for one hour followed by a 10 minute nitrogen purge of 10 cc/min while the reactor temperature dropped to 700"F. When methanol was passed over the bed, the temperature profile of the bed changed as shown in Table 5 after 2 hours on stream. The effluent stream from the reactor was collected between 1 and 2 hours on stream.

The run conditions and product analysis are shown in Table 6. In this, 87.2% of the methanol was converted, of which 17.8% went to an oxygen-free hydrocarbon product.

This product was 54.6% ethylene and 29.4% propylene.

Example 24 Addition of steam as a diluent improved the selectivity for ethylene. A charge solution comprised of 30% by wt of methyl alcohol and 70% by wt of water was passed over 1.0 gram of the catalyst from Example 22 at a rate of 3.6 grams per hour. The run was made at a nominal 700"F and atmospheric pressure. The catalyst bed had an axial bed length of 22 inches. The catalyst from Example 22 was calcined in place with an air flow of 10 cc/min at 1000"F for 5 hours followed by a 10 minute nitrogen purge of 10 cc/min while the reactor temperature dropped to 700"F. The temperature distribution of the bed after passing charge for two hours is shown in Table 5. The effluent stream from the reactor was collected between 1 and 2 hours on stream. Run conditions and product analysis are shown in Table 7. In the run, 72.2% of the methyl alcohol was converted, of which 41.4% went to oxygen-free hydrocarbon product. The selectivity for ethylene was 59.7%.

TABLE 5 Example No. 20 21 22 23 24 Hours on Stream 2 2 6 2 5.5 2 2 Axial Length of Bed (inches) 23/8 27/16 27/16 27/16 27/16 2 2 Temp., F. (inches from top) 0 638 674 675 682 685 682 660 688 696 692 694 698 698 697 1 698 703 698 698 700 695 703 1 693 700 699 698 696 700 701 2 687 708 705 707 706 714 710 23/8 692 27/16 715 716 712 718 2 715 721 TABLE 6 Example 20 Example 21 Example 22 Example 23 Charge MeOH DME MeOH MeOH Hours on Stream 2 2 6 2 5.5 2 Temp., F (nominal) 700 700 700 700 700 700 WHSV (on Recovered) 2.9 3.1 3.3 2.0 3.0 3.0 Conversion of Chg, Wt % 87.9 39.5 11.9 88.2 85.9 87.2 Product (Wt %): MeOH - 22.9 26.3 - - DME 31.2 - - 36.9 56.8 39.9 Water 47.5 22.6 11.0 40.3 34.4 41.9 Hydrocarbon Phase 21.0 54.2 62.7 22.4 8.6 17.8 Hydrocarbon Distribution Wt % C1 2.4 2.0 2.6 2.1 2.3 2.9 C2= 50.9 22.0 16.0 42.5 25.6 54.6 C2 0.5 0.2 0 0.4 0 0.7 C3= 27.3 15.3 8.0 26.1 17.6 29.4 C3 0.3 2.4 4.8 1.8 2.1 1.8 C4= 8.7 9.8 13.7 6.7 5.4 6.2 C4 4.1 8.7 7.9 3.8 1.9 1.4 C5+ 5.8 39.4 47.0 16.5 45.1 2.8 TABLE 6 Example 20 Example 21 Example 22 Example 23 Charge MeOH DME MeOH MeOH Hours on Stream 2 2 6 2 5.5 2 Temp., F (nominal) 700 700 700 700 700 700 WHSV (on Recovered) 2.9 3.1 3.3 2.0 3.0 3.0 Conversion of Chg. Wt % 87.9 39.5 11.9 88.2 85.9 87.2 Product (Wt %): MeOH - 22.9 26.3 - - DME 31.2 - - 36.9 56.8 39.9 Water 47.5 22.6 11.0 40.3 34.4 41.9 Hydrocarbon Phase 21.0 54.2 62.7 22.4 8.6 17.8 Hydrocarbon Distribution Wt % C1 2.4 2.0 2.6 2.1 2.3 2.9 C2= 50.9 22.0 16.0 42.5 25.6 54.6 C2 0.5 0.2 0 0.4 0 0.7 C3= 27.3 15.3 8.0 26.1 17.6 29.4 C3 0.3 2.4 4.8 1.8 2.1 1.8 C4= 8.7 9.8 13.7 6.7 5.4 6.2 C4 4.1 8.7 7.9 3.8 1.9 1.4 C5+ 5.8 39.4 47.0 16.5 45.1 2.8 TABLE 7 Example 24 Charge: MeOH/H2O Hours on Stream 2 Temp., F (nominal) 700 WHSV (Total) 3.6 of MeOH 1.2 of Water 2.4 Mole Ratio (H2O/MeOH) 3.4/1 Conversion of MeOH, wt % 72.2 Product (wt %) DME 3.9 Water (excludes water in charge) 54.7 Hydrocarbon Phase 41.4 Hydrocarbon Phase (Wt %) C1 1.6 C2= 59.7 C2 1.1 C3 23.6 C3 5.2 C4= 5.8 C4 1.3 C5= 1.4 C5 0.3 Example 25 A 603 gram sample of 14 x 25 mesh ion-exchanged ZSM-34 prepared as in Example 19 was calcined for 10 hours at 10000F. and then evacuated for 1/2 hour. Thereafter, the sample was contacted by shaking with 6.3 ml. of Zn(NO3)2 solution containing 0.291 gram Zn(NO3)2.6H2O (0.0636 gram Zn) to introduce about 1 weight percent of zinc. The resulting composite was then dried at 230 F. and calcined for 10 hours at 10000F. On analysis, the catalyst contained 0.96 weight percent zinc.

Methanol at a rate of 3.8 ml. per hour was passed over 1 gram of the above catalyst. The catalyst was air calcined in place at 10000F. for one hour with an air flow of 10 cc/minute.

Nitrogen at a rate of 10 cc/minute was passed over the bed for 10 minutes while the temperature dropped to 7000F. The run conditions, temperature profile of the bed and product analysis of the reactor effluent collected between 1 and 2 hours on stream are set forth in Table 8 below: TABLE 8 Example No. 25 Charge: wt% MeOH 100 Axial Length of Bed in inches 21 Reactor Diameter (mm OD) 8 Temp. Profile 0 679 Inches from top 1/2 705 1 705 697 2 710 Hrs. on Stream of Temp.

Profile 2 WHSV 3.0 Converted MeOH (wt. %) 88.7 Products (charge free) wt % Water 38.2 DME 42.0 HC Phase 19.5 HC Phase Composition (wt %) C1 2.6 C2= 45.2 C2 0.4 C3= 26.8 C3 0 C4= 6.5 C4 2.9 C5+ 15.5 It will be evident that of the 88.7 percent methanol converted, 19.5 percent went to oxygen-free hydrocarbon product, with an ethylene content of 45.2 weight percent.

A sample of the calcined alkali ZSM-34 of Example 10 was further processed by contacting with a 10 wt % NH4Cl solution for one hour at about 185"F using 10 ml of solution for each gram of ZSM-34. A total of four contacts were made at these conditions followed by final filtration and water washing essentially free of chloride ion.

The product was dried at 230"F and calcined for 10 hours at 10000F. The residual alkali content as Na was 0.035 wt % while the residual K content was 1.47 wt %. This product had a surface area of 517 m2/g and the following sorption capacity: Cyclohexane, wt % 2.6 n-Hexane, wt % 10.0 H2O, wt % 18.7 Example 27 A feed comprised of 30 wt % methanol and 70% water was passed over 2.0 g of the catalyst of Example 26 at a rate of 7.7 ml per hour. The catalyst contained in a 15 mm OD tubular glass reactor, had an axial bed length of 18 inches. The catalyst was air calcined in place at 10000F for one hour with an air flow of 10 cc/min. Nitrogen at a rate of 10 cc/min was passed over the bed for 10 min while the temperature dropped to 7000F. The run conditions, the temperature profile of the bed and the product analysis of reactor effluent samples taken at four different intervals during the run are set forth in Table 9 below: TABLE 9 Hours on Stream 1-2 4.5-5.5 7-8 11-12 Temp., "F 0 655 645 638 654 (inches from Top) 1/2 693 682 687 693 1 700 693 702 705 705 706 723 725 18 706 716 730 735 Temp. profile, Hrs. 2 5.5 8 12 Calculations on Recovered: WHSV Total 3.6 3.6 2.9 2.9 MeOH 0.86 1.0 0.81 0.76 Water 2.7 2.6 2.1 2.1 Converted MeOH (wt O/o) 96.0 65.4 37.1 33.8 Product (excludes unreacted charge) wt % DME 1.9 19.3 47.2 57.2 Water 55.5 48.7 37.8 33.8 HC Phase 42.6 32.0 15.0 8.9 HC Distribution (wt %) C1 1.8 3.0 4.9 7.5 C2= '~ 48.8 56.0 52.9 53.7 C2 1.8 0.4 0 0 C3= 26.8 27.2 27.7 25.8 C3 7.1 0 0 0 C4= 7.8 6.5 6.5 6.0 C4 3.3 4.7 3.6 4.5 C5 2.6 2.2 4.5 2.6 It will be seen from the above data that use of ZSM-34 in conversion of methanol afforded exceptionally high selectivity for ethylene and propylene. Dimethyl ether converted in the presence of this catalyst also gave good yields of ethylene, although somewhat lower than for methanol. Introduction of steam to the methanol feed served to improve the overall selectivity for ethylene.

Claims (27)

WHAT WE CLAIM IS:

1. A crystalline aluminosilicate zeolite having the composition, in terms of mole ratios of oxides; M2O : Awl203: (8-50) SiO2 n in which M represents a cation of valence n, said zeolite possessing an X-ray powder diffraction pattern substantially as set forth in Table 1 herein and being capable, after calcination at 1000"F for at least a period of time sufficient to remove any organic cation, of sorbing at least 9.5 weight percent of n-hexane at ambient temperature and a n-hexane pressure of 20 mm.

2. A zeolite according to Claim 1 wherein the mole ratio of SiO2/Al203 is 8 to 30.

3. A zeolite according to Claim 1 or Claim 2 wherein the mole ratio SiO2/Al203 is 8 to 20.

4. A zeolite according to any preceding claim wherein M comprises ammonium, hydrogen, rare earth metal, aluminum, manganese or a metal of Group II or VIII of the Periodic Table.

5. A zeolite according to Claim 1 which, in the anhydrous, as-synthesized form, has the chemical analysis in terms of mole ratios of oxides: (0.5 - 1.3) R2O: (0-0.15) Na2O: (0.1 - 0.5) K2O: Al2O3: (8-50)SiO2 in which R is an organic nitrogen-containing cation derived from choline.

6. A method of preparing a crystalline aluminosilicate zeolite which comprises forming a mixture containing sodium oxide, potassium oxide, silica, alumina, a choline compound and water having a composition, in terms of mole ratios of oxides, falling within the following ranges: SiO2/Al2O3 ------------------------------------------------------------------------- 10 - 70 OH-/SiO2 ------------------------------------------------------------------------- 0.3 - 1.0 H2O/OH- ------------------------------------------------------------------------- 20 - 100 K2O/X2O ------------------------------------------------------------------------- 0.1 - 1.0 R+/R+ + X+ --------------------------------------------------------------------- 0.1-0.8 where R+ is choline and X is sodium + potassium, and maintaining the mixture at a temperature between 80"C and 175 C until crystals of said zeolite are formed.

7. A method according to Claim 6 wherein said mixture has a composition falling within the following ranges: SiO2/Al2O3 ------------------------------------------------------------------------- 10 - 55 011 /Si02 0.3 - 0.8 H2O/OH- -------------------------------------------------------------------------- 20 - 80 K2O/X2O ------------------------------------------------------------------------- 0.1 - 1.0 R+/R+ + X+ -------------------------------------------------------------------- 0.1-0.50

8. A method of preparing zeolite ZSM-34, substantially as described in any of Examples 1 to 11 inclusive.

9. Zeolite ZSM-34 whenever prepared by the method claimed in any of Claims 6 to 8.

10. A process for converting an organic charge which comprises contacting said charge, under conversion conditions, with a catalyst comprising a zeolite according to any of claims 1 to 5 and 9, wherein said conversion is the cracking, hydrocracking or alkylation of hydrocarbons; the isomerisation of n-paraffins and naphthenes; the polymerization of compounds containing an olefinic or acetylenic carbon-to-carbon linkage; reforming, or the isomerisation of polyalkyl substituted aromatics; the disproportionation of aromatics to provide a mixture of benzene. xylenes and higher methylbenzenes; or the conversion of methanol and/or dimethyl ether to ethylene and/or propylene.

11. A process according to Claim 10 wherein the charge is hydrocarbon and the conversion is polymerisation.

12. A process according to Claim 10 wherein the conversion is the polymerisation of propylene, isobutylene or butene-l.

13. A process according to Claim 10 wherein the conversion is reforming, or the isomerisation of orthoxylene.

14. A process according to Claim 10 wherein the conversion is the disproportionation of toluene.

15. A process according to Claim 10 wherein the charge is hydrocarbon and the conversion is cracking.

16. A process according to Claim 10 wherein the charge comprises methanol and/or dimethyl ether and the conversion yields a hydrocarbon product rich in ethylene and propylene, said conversion conditions comprising a temperature between 500 F and 1000 F, a pressure from 0.1 to 30 atmospheres and a weight hourly space velocity between 0.1 and 30.

17. A process according to Claim 16 wherein ethylene and propylene constitute the major proportion of the hydrocarbon reaction product.

18. A process according to Claim 16 or Claim 17 wherein the ethylene content of said product exceeds the propylene content.

19. A process according to any of Claims 16 to 18 wherein the amount of ethylene and propylene produced exceeds 35 weight percent, and the amount of methane produced is not more than 10 weight percent, of the hydrocarbon reaction product.

20. A process according to any of Claims 10 to 19 wherein said zeolite has been thermally treated at a temperature of 200"C to 750"C.

21. A process according to any of Claims 10 to 20 wherein at least 10 percent of the cation sites of said zeolite are satisfied by ions other than alkali or alkaline earth metals.

22. A process according to Claim 21 wherein said ions are hydrogen, hydrogen precursors, metals from Groups IB, II, III, VIIB, VIII or rare earth metals.

23. A process according to Claim 22 wherein said ions are hydrogen and/or rare earth.

24. A process according to any of Claims 10 to 23 wherein said zeolite is predominantly in the hydrogen form.

25. A process according to any of Claims 10 to 24 wherein said zeolite is in the form of a composite with a matrix.

26. A process according to any of Claims 10 to 25 wherein said zeolite has been subjected to steam treatment for 1 to 100 hours at a temperature of 700 to 1200"F.

27. A process of catalytic conversion of an organic charge substantially as described in any of the foregoing Examples 12 - 27.