GB1604190A

GB1604190A - Interlayered smectite clay for use as catalyst

Info

Publication number: GB1604190A
Application number: GB2477578A
Authority: GB
Original assignee: WR Grace and Co
Current assignee: WR Grace and Co
Priority date: 1977-06-13
Filing date: 1978-05-31
Publication date: 1981-12-02
Also published as: NL7806339A; DE2825769A1; FR2394324A1; MX147711A; JPS6220130B2; CA1106346A; AU3704278A; AU518419B2; FR2394324B1; JPS5416386A; DE2825769C2

Description

(54) INTERLAYERED SMECTITE CLAY FOR USE AS CATALYST (71) We, W. R. GRACE & CO., a Corporation organized and existing under the laws of the State of Connecticut, United States of America, of Grace Plaza, 1114, Avenue of the Americas, New York, New York 10036, 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:- The resent invention relates to novel clay-derived compositions, and more specifically to interlayered derivatives of smectite type minerals -(layered clays) which possess considerable internal micropore volume and have useful catalytic and adsorbent properties.

Layered naturally occurring and synthetic smectites such as bentonite, montmorillonites and chlorites may be visualized as a "sandwich" comprising two outer layers of silicon tetrahedra and an inner layer of alumina octahedra. These "sandwiches" or platelets are stacked one upon the other to constitute a clay particle. Normally this structure is repeated every nine angstroms or thereabouts.

Much work has been done to demonstrate that these platelets can be separated further, i.e. interlayered, by insertion of various polar molecules such as water, ethylene glycol, and various amines and that the platelets can be separated by as much as 30 to 40 A. Furthermore, prior workers have similarly prepared phosphated or alumino-phosphated interlayered clays as low temperature traps for slow release fertilizer. The interlayered clays thus far prepared from naturally occurring smectites are not suitable for general adsorbent and catalytic applications due to the fact they tend to collapse when subjected to high temperatures.

The products of the present invention can be prepared from naturallyoccurring smectites, which are preferred for cheapness and ready availability, but can also be prepared from synthetic layered clays such as disclosed in U.S. Patents Nos. 3,803,026, 3,844,979, 3,887,454, 3,896,655, 3,275,757, 3,252,889, 3,586,478, 3,666,407, and 3,671,190. Natural clays which may be used include hectorite, chlorite, bentonite, montmorillonite, beidellite and substituted analogues thereof.

According to the present invention, there is provided an interlayered srmectite clay, having an interlayer spacing of 6 to 16 A and the layers of which are separated by an inorganic oxide comprising alumina, zirconia or a mixture thereof, the clay having more than 50 ,ZO of its surface area in pores less than 30 A in diameter.

The interlayered clay of this invention can be prepared by reacting in water a smectite clay (e.g. one of those mentioned above) with a polymeric cationic complex containing hydroxy-aluminium and/or -zirconium to obtain an interlayered smectite, which, when the complex is converted to the metal oxide, has greater than 50 percent of its surface area in pores of less than 30 A in diameter and an interlayer spacing of 6 to 16 A, separating the smectite from the aqueous reaction medium, and then heating the interlayere smectite to convert the complex to the metal oxide. The heating is desirably effected by calcining the interlayered smectite at a temperature of 200 to 7000 C. The uncalcined product could, of course, be prepared merely by omitting this heating step.

Two distinctive features of the clays of this invention are these 1. The inorganic oxide, which holds apart successive layers of siliconcontaining clay material, is in the form of pillars, i.e. discrete (non-continuous) particles. These pillars serve to prop open the clay layers upon removal of water and form an internal interconnected micropore structure throughout the interlayer in which the majority of the pores are less than 30 A in diameter.

2. In consequence of the "pillared" structure, the interlayered clay of this invention containing inorganic oxide pillars has a microporosity such that at least 50 /0 of its surface area is in pores less than 30 A in diameter (as determined by conventional pore size distribution measurements using nitrogen as absorbent).

More specifically, we have found that thermally stable interlayered clays which have an interlayer spacing of up to 16 A and greater than 50 /O of its surface area in pores of less than 30 A in diameter may be prepared by the above method.

A clearer understanding of preferred embodiments of our invention may be obtained from the following detailed description, specific examples, and drawing wherein: Figure 1 represents a cross-sectional view of the structure of a typical smectite type clay which may be used to prepare the novel interlayered clay products of our invention.

Figure 2 is a cross-sectional view of a clay of Figure 1 which has been treated with a polymeric cationic hydroxy-metal (aluminium or zirconium) complex to form a pillared interlayer between the clay layers; and Figure 3 represents the composition of Figure 2 which has been calcined to convert the interlayered polymeric complex into "pillars" of stable inorganic oxide (alumina and/or zirconia).

To obtain the novel pillared interlayer clay products of our invention the following general procedure is preferably used: 1) A smectite clay is mixed with an aqueous solution of the polymeric cationic complex, such as "chlorhydrol", in amounts wherein the weight ratio of clay to complex solution is from 1:2 to 1000. The aqueous solution of the complex will preferably contain from 1 to 40 /O by weight dissolved solids. Typically from 0.05 to 2.0 parts by weight of complex is mixed with each part by weight of the smectite.

2) The mixture of clay and complex is maintained at a temperature of 5 to 200"C for a period of 0.1 to 4.0 hours.

3) The reacted clay solids are recovered and heated at a temperature of from 200 to 7000C to decompose the complex to a pillar of inorganic oxide.

The clays used as starting materials in the present invention are the group of minerals commonly called smectites and typically represented by the general formula: (Sis)N(Al4)VIOn(OH)4 where the IV designation indicates an ion coordinated to four other ions typified by silicon as shown, and VI designates an ion typified by aluminium as shown coordinated to six other ions. The IV coordinated ion is commonly Si4+, Al3+ and/or Fe3+, but could also include several other four coordinate ions (e.g. P5+, B3+, Ge4+ or Be2+). The VI coordinated ion is commonly Al3+ or Mg2+, but could also include many possible hexa-coordinate ions (e.g. Foe3 , Fe2+, Ni2+, Co2+ or Li+). The charge deficiencies created by the various substitutions into these four and six coordinate cation positions, are balanced by one or several cations located between the structural units. Water may also be occluded between these structural units, bonded either to the structure itself, or to the cations as a hydration shell. When dehydrated, the above structural units have a repeat distance of about 9.1 A, measured by X-ray diffraction. Typical commercially available clays include montmorillonite, bentonite, beidellite and hectorite.

The inorganic oxide polymers used in the present invention are generally known as basic aluminum or zirconium complexes which can be formed by the hydrolysis of various aluminum or zirconium salts, e.g. aluminum chlorohydroxide, otherwise known simply as "chlorhydrol" and zirconium oxychloride. While there is some disagreement on the nature of the species present in the solution or suspensions, it is generally believed that these mixtures contain highly charged catlonic complexes containing several metal atoms per molecule.

The inorganic aluminum polymers which may be used to prepare our novel pillared interlayered clay compositions comprise solutions of discrete polymer particles having a generally spherical shape and a diameter of about 8 and in which the aluminum atoms are present in the tetrahedrally coordinated form to an extent of up to about 10% as determined by NMR measurement as shown by Rausch and Bale, in J. Chem. Phys. 40 (II), 3391 (1964), the remainder being octahedrally coordinated. The typical hydroxy-aluminum polymers previously used to produce uniform gibbsite layers between clay layers, are characterized by the presence of substantially 100% octahedrally coordinated aluminum in the form of gibbsite-like sheet polymers.

When AlCI3 - 6 H2O dissolves in water, it ionizes as follows: Al(H20)6++++3CIwith most of the Cl being ionic. Since such solutions are acidic, then hydrolysis must take place to a substantial degree, particularly in view of the relatively high value of the ratio of ionic charge to ionic radius which characterizes the aluminum ion. The initial hydrolysis step is Al(H2O)[AkH2O)5OH]+++H+ and the complex ion formed by this hydrolysis is basic. In the usual terminology of such complexes, this hydrolysis product is "1/3 basic". Such a species is present in acidic aluminum chloride solutions, since hydrolysis is responsible for the acidity of these solutions.

As a means of better understanding these basic polymers, it is important to differentiate between the basicity of a solution and the basicity of a complex ion in solution. The nature of the polymer species present is dependent on pH, concentration and temperature. Lowering the pH by addition of H+ shifts the hydrolysis reaction to the left, causing a decrease in the average molecular weight of the polymer. It is important to note that the total basicity of the complexes will always be greater than the basicity of the solution per se, because of the factor of hydrolysis. Increasing concentration and higher temperatures favor increased degrees of hydrolysis, leading to larger polymers.

The hydrolysis of cations brings about polymers through a process called olation, which is described by C. L. Rollinson in Chemistry of the Coordination Compounds, Edited by J. C. Bailar, Reinhold Publishing Corporation, New York, 1956, as follows:

In this process single or double OH bridges can be formed between Al ions. In less acidic solution, larger polymers are formed by the process and the bridging OHcan be converted to bridging 0-2, a process called oxolation. Note that a doubly OH bridged complex is a pair of edge-sharing octahedra, and this is the same type of structure found in boehmite, ALOOF, where the OH groups at the surface of the layers are each shared between two AlO0 octahedra. In hydrargillite, A1(OH),, all oxygens are also shared between two Aloof octahedra.

Some of the prior art methods that have been used to prepare Al polymers include: a) Tsutida and Kobayashi, J. Chem. Soc. Japan (Pure Chem. Sec.), 64 1268 (1943), disclose the reaction of solutions of AlCl3. 6 H2O or HCI with an excess of metallic aluminum;

b) Inove, Osugi and Kanaya, J. Chem. Soc. Japan (Ind. Chem. Sec.), 61, 407 (1958), discloses that more than an equivalent amount of aluminum hydroxide is reacted with an acid:

c) H. W. Kohlschuter et al., Z. Anorg. Allgem. Chem., 248, 319(1941) describe a method wherein alkali is added to an aluminum salt solution;

d) T. G. Owe Berg, Z. Anorg. Allgem. Chem., 269, 213 (1952), discloses a procedure wherein an aqueous solution of AIX3 is passed through an ion exchange column in OH- form, and e) R. Brun, German Patent No. 1,102,713, describes extending heating at l500C. of salts such as AlCI3. 6H2O.

The inorganic aluminum polymers used in the practice of the present invention are visualized as having the general formula: Al2+n (0H)3nXs wherein n has a value of 4 to 12; and X is usually Cl, Br, and/or NO3. These inorganic metal polymers are believed to have an average molecular weight of from about 300 to 3,000.

Zirconium complexes and their preparation are described in: 1) A. Clearfield and P. A. Vaughan, Acta Cryst. 9, 555 (1956); 2) A. N. Ermakov, I. N. Marov, and V. K. Belyaeva, Zh. Neorgan. Khim. 8 (7), 1623 (1963).

3) G. M. Muha and P. A. Vaughan, J. Chem. Phys. 33, 19W9 (1960).

It is also contemplated that copolymers of the above aluminium and/or zirconium complexes with silicon and magnesium oxides may be used.

Furthermore, it is contemplated that the hydrated or dehydrated complex-treated smectite clays may be post treated with solutions of silicate, magnesium, and phosphate ions to obtain more stable and attrition-resistant compositions.

The catalytic and adsorbent characteristics of the interlayered smectite clays of the present invention may be modified by ion exchange with a wide variation of cations including hydrogen, ammonium, and metals of Groups IA to VIII of the Periodic Table, according to "Advanced Inorganic Chemistry" by F. A. Cotton and G. Wilkinson, 3rd ed. 1972. In particular, catalytic cracking and hydrocracking catalysts which contain rare earth, cobalt, molybdenum, nickel, tungsten, and/or noble metal ions are active for the catalytic conversion of hydrocarbons.

Referring to the drawing, Figure 1 represents a typical smectite wherein the layers or platelets have a repeat distance d, of about 9 to 12 A depending on the degree of hydration. As shown in Figure 2, smectites which have been treated with complex polymers in accordance with the teachings of the present invention, have an increased repeat distance of d2 of from about 16 to about 24 A. In Figure 3, a platelet repeat distance d3 which is less than d2 is shown in exaggerated form. The repeat distance d3, which is established when the pillared metal complex polymer inserted between the platelets is decomposed by calcination to temperatures of about 200 to 700cC, is found in practice to be substantially the same as d2, with only minor shrinkage of the pillared layer occurring to the extent of less than 0.5 A in cases. All the distances d1, d2 and d3 (layer repeat distances) are readily obtained directly from the X-ray diffraction patterns of the various products, and represent the first-order basal reflection parameter (i.e. 001). The "interlayer distances" are obtained by subtracting the thickness (about 9 A) of the clay layer from the basal spacing obtained by X-ray diffraction, i.e. d4=dl-9; d5=d2-9; and d6=d3-9.

Recent research on the clay minerals has shown that within a given clay structure the layers are not uniform, but form a heterogenous chemical mixture in which the exact composition of one layer may be somewhat different from that of an adjacent layer. This would be expected to result in slight variations in charge between layers, and therefore, slight differences in the amount of polymer exchanged in different layers. As the size of the polymer is the controlling factor in setting the interlayer distance, charge heterogeneity on the layers would only affect the number of polymer species between the layers (i.e. the number of resultant pillars, not their size).

In general, the calcined products of our invention will usually have an interlayer spacing of 6 to 16 A, a nitrogen BET surface area of 150 to 600 m2/g, and a nitrogen pore volume of 0.1 to about 0.6 cc/g. They have a substantial internal micropore structure which is characterized by a pore-size distribution in which more than 50%, and in many cases more than 75%, of the surface area is located in pores less than 30 A in diameter as determined by conventional nitrogen pore size distribution adsorption measurements.

In Examples 1 and 2 below, the percentage of the total surface area which is provided by pores less than 20 A in diameter is 75.7 and 72.3% respectively, so the percentage provided by pores less than 30 A in diameter is even greater. All other Examples give products meeting the porosity requirements defined above for the products of the invention.

In contrast known gibbsite-like interlayered clay products (synthetic chlorites) possess no substantial surface area in pores less than 30 A in diameter.

Our interlayer products are useful as adsorbents and catalytic supports.

Furthermore, it is contemplated that our interlayered clay products may be combined with other inorganic oxide adsorbents and catalysts such as silica, alumina, silica-magnesia, silica-alumina hydrogel, and natural or synthetic zeolites, and clays. Our products are particularly useful in the preparation of catalysts which contain active/stabilizing metal such as platinum, palladium, cobalt, molybdenum, nickel, tungsten, and rare-earths, as well as matrix components such as silica, alumina or silica-alumina hydrogel. These catalysts are used in conventional petroleum conversion processes such as catalytic cracking, hydrocracking, hydrotreating, isomerization and reforming catalysts; and as molecular sieve adsorbents.

The following specific examples are given to illustrate preferred specific embodiments of the invention. In these examples, the product was dried in an oven at a temperature of about 1000 F (540"C) for about one hour as part of the determination of surface area, and this drying effected the conversion of the metal complex in the interlayer to metal oxide. "Volclay" is a Registered Trade Mark.

Gallons are U.S. gallons.

Example I A clay slurry was prepared from the natural clay product designated Volclay 200 by American Colloid Co. To a total of 32,000 ml. of a clay slurry containing 2.7 percent by weight solids was added 1110 grams of an aluminum chlorohydroxide solution, prepared to contain 50 weight percent of the salt. The resulting mixture was aged for one half-hour with agitation and the temperature was increased to 160"F. The slurry was aged for 1/2 hour at this temperature, the product was filtered, washed once with 16 gallons of hot deionized water, reslurried in deionized water and spray-dried. The properties of the product are set out in Table 1.

Example 2 A total of 31.7 gallons of slurry of the less than or equal to 2 micron sized particles of the natural clay product designated Volclay 200 by American Colloid Corporation was prepared by centrifugation. A 50 weight percent solution of aluminum chlorohydroxide was prepared and 6,920 grams of the resulting solution was added to the clay slurry. The slurry was aged for 1/2 hour at 1600F and filtered on a belt filter. The filter cake was reslurried in deionized water; refiltered and again reslurried in deionized water and spray-dried. The properties of the interlayered clay product are set out in Table 1 below.

The catalytic activities of these products were determined using the microactivity test described in the article by Ciapetta et al. in the Oil and Gas Journal of October 16, 1967. The feed stock was a West Texas gas oil boiling in the range of 500 to 8000F The reactor was operated at a temperature of 920 F., a weight hourly space velocity of 16 and had a catalyst/oil ratio of 3. The product of Example 1 gave a 98.6% conversion, and the product of Example 2 gave a conversion of 82.5%.

TABLE I Product of Example 1 Example 2 Surface Area(1 hr., 7500 F) 476.6 m2/g. 372.5 m2/g.

Interlayer spacing, d(001), A 19.0 19.0 Average Bulk Density IbJcu.ft. 0.48 0.80 Compacted Density IbJcu.ft. 0.71 0.98 Attrition Davison Index 4.60 8.00 Jersey Index 2.30 1.10 Size Distribution in Percent 0--20 microns 21 7 0--40 microns 83 36 0--80 microns 92 76 0--105 microns 96 87 W149 microns 98 97 Average Particle Size 29 54 Surface Area Surface Area Pore Diameter (m2/g.) (m2/g.) > 600 A 1.2 0.6 10600A 4.2 1.7 20--100 A 109.2 101.0 < 20 A 362.0 269.2 Total Surface Area 476.6 372.5 Catalytic Activity (% Conversion) 98.6 82.5 Example 3 One of the problems encountered in the preparation of these slurries where the particle size is equal to or less than 2 microns is the tendency to lose part of the product through the filter. To combat this problem a flocculating agent was added to the clay slurry.

A batch of interlayered clay was prepared in Example 1, varying amounts of a high molecular weight GUAR, designated polymer 7050-B by Stein, Hall & Co., were added to portions of the clay slurry. Each sample was filtered on both a coarse (2-3 cubic feet/minute) and a fine (1 cubic foot/minute) filter cloth. Results from the 0.5 to 10 g polymer/100 g clay indicated thickening at all levels, but I to 3 g/100 grams appeared to yield the clearest filtrates. When slurries were prepared without a flocculating agent, a considerable amount of product was lost through the coarse filter cloth.

The flocculations can also be affected by an addition of low levels of sodium silicate (0.5 g. SIO2/100 g clay). There was little loss in product surface area with this treatment. Other flocculating agents of the anionic or neutral type would be equally effective.

Example 4 This example illustrates the use of calcium bentonite as the raw material in our novel process.

A slurry of particles having a particle size of equal to or less than 2 microns of calcium bentonite furnished by American Colloid Corporation was prepared by centrifugation. A total of 26.7 g (dry basis) of clay from this slurry was diluted to 5.4 litres and 38.0 g of a 50 weight percent aluminum chlorohydroxide solution was added. The slurry was aged for 1/2 hour at 250C., and the pH was then adjusted to 2.0 with a 3.75% hydrochloric acid solution. The slurry was then aged for 1/2 hour at a temperature of 1600 F., filtered, washed with 2.7 litres of hot deionized water and oven-dried. The product recovered had a surface area of 350 m2/g and a (001) basal spacing of 17.5 A.

Example 5 This example illustrates the use of beidellite clay as a raw material.

A slurry was prepared from 15 g (dry basis) of beidellite clay from Taiwan having a particle size of equal to or less than 2 microns. The particles having a particle size of equal to or less than 2 microns were recovered by centrifugation. A total of 15 g (dry basis) of the clay was diluted to 3 litres and 15.1 of a 50 weight percent aluminum chlorohydroxide solution was added. The resulting slurry was aged for a period of 1/2 hour. The pH was adjusted to 2.0 with 3.75 percent hydrochloric acid solution. The temperature was increased to 1600F and the slurry was aged at this temperature for a period of 1/2 hour. The siurry was filtered, washed with I litre of hot deionized water and oven dried. The surface area of the product was 307 m2/g and the (001) basal spacing was 18.0 A.

Example 6 This example illustrates a method of using a beneficiated montmorillonite without having to separate the particles of size equal to or less than 2 microns. A 25 g (dry basis) sample of a high purity air-floated Wyoming bentonite furnished by American Colloid Company (No. 325 Bentonite) was slurried in a blender with 1 litre of deionized water for 1/2 minute. A total of 21.5 g of a 50 percent aluminum chlorohydroxide solution was added and the slurry was aged for 1/2 hour at 150 F.

The product was filtered, washed with 1 litre of hot deionized water, and ovendried at 1 100C. The surface area of this product was 308 m2/g.

Example 7 This example illustrates the product distribution of a typical product prepared from the product described in Examples 1 and 2. The catalytic activity of the product was listed as described in Example 1. The test was carried out after the catalysts had been exposed to a temperature of 1000"F for a period of 3 hours. The data collected in this run is set out in Table II below.

TABLE II Pillared Interlayered Clay Conversion prepared from Volclay 200.

Conv., * V% 77.3 H2, ** W% .27 C1, W% .90 C2=, W% .71 C2, 94 Total C3, W% Total Dry Gas, W% 8.5 C3=, V% 5.4 C3, V% 4.2 Total C3, V% 9.6 C4=, V% 2.6 iso-C4, V% 8.0 Normal-C4, V% 1.7 Total C4, V% 12.3 C4+gasoline., V% 66.9 Cs+gasoline, V% 54.6 Coke on Cat., W% 4.5 Coke-Total feed, W% 12.8 *V%=Volume percent **W%=Weight percent Example 8 It has been found that if the clay was added to the aluminum chlorohydroxide solution a larger solids concentration could be affected. Such additions to the aluminum chlorohydroxide solution may be as high as about 40 weight percent clay without encountering problems in mixing, pumping, or handling the clay in the fluid state. This greatly enhances the economy of the process in that much larger volumes of the product can be obtained and processed in a given time for a given sized system. The addition of clay to water followed by aluminum chlorohydroxide addition does not allow high solids levels to be achieved. The former process is presumably achieved because the polymer is instantaneously intercallated by the clay as the clay is added, and so inhibits dispersion of the clay platelets and subsequent formation of a clay-water gel.

A further advantage is that high solids cut down the use of energy in the drying step.

In an illustration of this, a total of 2,470 g of a 50 weight percent of aluminum chlorohydroxide solution was diluted to 22.7 litres. A total of 5,32gig. (5,072 g dry basis) of bentonite was added to the slurry. The slurry was aged at 1500 F. for a period of 1 hour and spray dried. The solids concentration of the product fed to the spray drier was approximately 20 percent, the product recovered had a surface area of 273 m2/g and a lattice d spacing (001) of 17.9 A.

Example 9 In this example a slurry containing 15.9 percent solids was prepared by diluting 2,720 g of aluminum chlorohydroxide to 6 gallons and 5000 g (dry basis) of the clay was added to this slurry. The slurry was agitated and aged 1/2 hour at 1500 F., filtered, and washed on the filter with 6 gallons of hot deionized water. The product was reslurried and spray dried. The surface area of the product recovered was 316 m2/g. and the d spacing (001) was 18 A.

Example 10 In this example a slurry containing a 35 percent total solids was prepared by addition of 125 g (dry basis) No. 325 Bentonite clay (American Colloid Co.) to a solution containing 65.2 g of the aluminum complex polymer in a total volume of 250 ml. This slurry was aged I hour at 1500 F., filtered, washed with 1/2 1 hot deionized water and dried. The product surface area was 263 m2/g and the (001) d spacing was 17.6 A.

Example 11 In this example a less basic Al polymer is used to interlayer the smectite.

Ordinary aluminum chlorohydroxide (chlorhydrol) contains 5 OH-/2 Al+3 and is 5/6 basic. 10 g (dry basis) of c2.0 micron Volclay 200 (American Colloid Co.) as a slurry was diluted to 1.01 and 9.30 g of a 2/3 basic Al-complex polymer (i.e. 4 OH-/2 Al+3) solution containing 19.2% Al203 was added. This polymer solution was prepared by refluxing an AlCl3 .6 6 H2O solution in the presence of excess aluminum metal until pH 2.8 was reached. The above slurry was hot aged 1/2 hour at 150"F, filtered, washed 2x with 1/2 litre hot deionized water and oven-dried. The interlayered product had a surface area of 286 m2/g. and a basal spacing of 17.1 A.

Example 12 This example indicates that smectites can be interlayered with Al-complex polymer prepared from dehydrated AlCI3 .6 H2O. 9.1 g of AlCI3. 6 H2O was weighed in an evaporating dish, the dish placed in a muffle furnace set at 325"F for one hour and the temperature then increased to 5000 F. The sample was withdrawn from the furnace after a 45% weight loss. The salt was then added to 200 ml of deionized water, 12.5 g (dry basis) of No. 325 Bentonite (American Colloid Co.) was added, the slurry hot aged I hour at 1500F, filtered, washed 2x with 250 ml hot deionized water and dried a

Example 15 This example shows that interlayering of smectite can be accomplished at elevated temperature and pressure. 13.6 g chlorhydrol (Reheis Chemical Co.) was diluted to 200 ml with deionized water, 25 g (dry basis) No. 325 Bentonite added and the slurry boiled 1 hour. 20% of the above slurry was added to a Hoke high pressure cylinder and aged I 1/2 hours at 1500C. The interlayered clay product was then filtered, washed 2x with 250 ml hot deionized water and oven-dried, The product had a surface area of 279 m2/g and a basal spacing of 17.7 A.

Example 16 This example indicates that interlayered smectites prepared from chlorhydrol and Mg+2 cations are more hydrothermally stable than those prepared from chlorhydrol exchange alone. 54.4 g chlorhydrol was diluted to 1.6 litres and then.

400 ml of a solution containing 40.8 g. MgCl2 6 H2O was added and the mixture aged 3 days at room temperature. 100 g (dry basis) of No. 325 Bentonite was added, the slurry hot aged 1 hour at 160"F, filtered, washed 2x with 1.0 litre hot deionized water and oven-dried. As indicated below, this preparation maintained a greater degree of surface area after a 6 hour, 1400"F, 1 atmosphere steam treatment than smectite interlayered with chlorhydrol alone.

Surface Area Interlayering Species 1 hr. 1000 F 6 hr. 14000F I Atm.

Chlorhydrol 270 20 Chlorhydrol+Mg+2 310 104 Example 17 This example indicates that refluxed ZrOCl2 4 4H2O solutions are effective in interlayering smectite. 0.33 M ZrOCl2. 4 H2O was refluxed for 24 hours and then 120 ml of this solution was diluted to 500 ml., 10 g (dry basis) HPM-20 (American Colloid Co.) added, aged 1/2 hour at room temperature, filtered, washed 2x with 1/2 litre hot deionized water and oven-dried. The interlayered product had a surface area of 288 m2/g and a basal spacing of 22.0 A.

Example 18 This example shows that ZrOCl2 41120 solutions treated with Na2CO3 can effectively interlayer smectites. 125 g ZrOCl2. 4 H2O was dissolved in 1/2 litre solution. To this solution was added dropwise 1/2 litre of solution containing 26.5 Na2CO3. After aging for 24 hours, 50 ml of the above solution was diluted to litre, 10 g (dry basis) HPM-20 added, the slurry hot-aged 1/2 hour at 1500F, filtered, washed 2x with 1/2 litre hot deionized water and oven dried. The product had a surface area of 309 m2/g and a basal spacing of 17.4 A.

Example 19 This example shows how CO2-treated ZrOCl2 4 H2O solutions can effectively interlayer smectite. 125 g of ZrOCl2 4 4H2O was dissolved in I litre of deionized water. CO2 (gas) was bubbled through the solution for 2 hours, and the solution aged 24 hours at room temperature. 50 ml of this solution was then diluted to 1/2 litre, 10 g (dry basis) HPM-20 (American Colloid Co.) was added, the slurry hotaged 1/2 hour at 1500 F, filtered, washed 2x with 1/2 litre hot deionized water and oven dried. The interlayered clay had a surface area of 279 m2/g and a basal spacing of 16.8 A.

Example 20 This example shows that diluted chlorhydrol when refluxed, gives interlayered smectites with improved hydrothermal stability relative to non-refluxed chlorhydrol. 217 g chlorhydrol was diluted to 1.0 litre, yielding a solution which is 0.5 M as Awl203. This solution was refluxed for 96 hours. 87.6 ml of this solution was diluted to 400 ml, 25 g (dry basis) No. 325 Bentonite added, the slurry boiled 1 hour, filtered, washed 2x with 1/2 litre hot deionized water and oven-dried. As indicated below, this preparation had a greater retention of surface area than an interlayered clay prepared with ordinary chlorhydrol.

Surface Area Starting Material 1 hr. 1000 F 6 hr. 1400"F 1 Atm.

Chlorhydrol 270 20 Refluxed diluted chlorhydrol 271 82 Example 21 This example shows that treatment with SiO3-2 of either diluted refluxed chlorhydrol or ordinary chlorhydrol results in a substantial improvement of the interlayered product. 43.8 ml of diluted (0.5 M in At203) refluxed (48 hours) chlorhydrol was diluted further to 500 ml 1.26 g of Na2SiO3 solution (containing 28.5% SiO2 and 8.0% Na2O) diluted to 100 ml was added to the refluxed chlorhydrol solution. 12.5 g (dry basis) No. 325 Bentonite was added, the slurry boiled 1 hour, filtered, washed 2x with 1/2 litre hot deionized water and oven-dried.

Silicating ordinary chlorhydrol also substantially improves the hydrothermal stability of the interlayered clay. 8.5 g chlorhydrol was diluted to 900 ml and then 1.26 g of Na2SiO3 solution (28.5% SiO2, 8.0% Na2O) diluted to 100 ml was added to the dilute chlorhydrol solution. After aging overnight at room temperature, 12.5 g (dry basis) No. 325 Bentonite was added, hot-aged 1 hour at 1500 F, filtered, washed 2x with 1/2 litre hot deionized water and oven-dried.

Summarized below is a comparison of the hydrothermal stability of both of the above interlayered clays with ordinary chlorhydrol-interlayered clay.

Surface Area Starting Material 1 hr 1000 F. 6 hr. 1400"F I Atm.

Chlorhydrol 270 20 Chlorhydrol+SiO3~2 294 129 Refluxed diluted chlorhydrol +SiO3-2 353 165 Example 22 This example illustrates the use of the pillared interlayered clays as sorbents for organic molcules.

202 g of a < 2.0 N slurry of Volclay 200 (American Colloid Co.) which corresponds to 4.25 g on a dry basils, was added to 400 ml of solution containing 7.6 g of aluminium chlorohydroxide solution (Reheis Chemical Co.). The slurry was aged 1 hour with agitation, centrifuged, reslurried in deionized water and recentrifuged. The product was then reslurried in a second solution of 7.6 g aluminum chlorohydroxide diluted to 1.0 litre. After aging for I hour the slurry was centrifuged, reslurried in deionized water, recentrifuged and oven dried overnight at 2500 F. The sample was then ground and tested for n-butane and iso-butane capacity after several batches were prepared. This sample had an n-butane capacity of 7.74% and an iso-butane capacity of 7.13%. The surface area of this sample was 393 m2/g and the basal spacing was 17.7 Example 23 This example shows the usefulness of pillared interlayered clays as hydrocracking catalyst base. 2,720 g of chlorhydrol was diluted to 6 gallons and 5,000 g (dry basis) No. 325 Bentonite was added with vigorous agitation. The slurry was hot aged 1/2 hour at 1500 F, filtered and washed once on the filter with 6 gallons of hot water. The filter cake was reslurried to 15.9% solids and spray dried. The product surface area was 316 m2/g and the basal spacing was 18.0 A. A portion of this material was exchanged with 0.5% Pd, blended at a ratio of 9 parts interlayered clay/l part Awl203, reduced (2 hours at 5000F, 12 hours at 7000F in 71 litres/hour flowing H2) and then calcined for 3 hours at 100"F. The hydrocracking test was run at I LHSV, 1500 psig and 8000 SCF/B H2. The interlayered clay hydrocracking catalyst gave 16% conversion at 6750 F, compared to 6% conversion for a 0.5 W0,/o Pd impregnated 28% Awl203, 72% SiO2 catalyst.

Example 24 This example shows the general usefulness of interlayered clays for water sorption. The same interlayered clay sample (without Pd) as described in Example 23 was used for the water sorption measurements. The sample was calcined 1 hour at 10000F before the test. The results, given as % water sorption with varying relative humidity (RH), indicate substantial ability to sorb water. TV=total volatiles.

TV at 17500F 4.85 Ads. 10% RH 2.56 Ads. 20% RH 4.78 Ads. 35% RH 9.30 Ads. 60% RH 12.48 Ads. 100% RH 19.76 The capacity as a dehydrating agent is comparable to silica gels and zeolites.

WHAT WE CLAIM IS: 1. An interlayered smectite clay having an interlayer spacing of 6 to 16 Â, wherein the layers are separated by an inorganic oxide comprising alumina, zirconia or a mixture thereof and wherein the clay has more than 50% of its surface area in pores less than 30 A in diameter.

2. An interlayered smectite clay according to Claim I wherein said inorganic oxide is alumina.

3. An inter layered smectite clay according to Claim 1 wherein said inorganic oxide is zirconia.

4. An interlayered smectite clay according to Claim 1 wherein said inorganic oxide is silica-alumina.

5. An interlayered smectite clay according to Claim 1 wherein said inorganic oxide is alumina-magnesia.

6. An interlayered smectite clay according to any preceding claim wherein the smectite is hectorite, chlorite, bentonite, montmorillonite, beidellite or a substituted analogue thereof.

7. An interlayered smectite clay according to any preceding claim which has been exchanged with cations selected from hydrogen, ammonium and metals of Group EA to VIII of the hereinbefore defined Periodic Table, and mixtures thereof.

8. A smectite according to Claim I substantially as described in any one of the Examples.

9. A process for preparing an interlayered smectite clay, which process comprises reacting a smectite clay in water with a polymeric cationic complex containing hydroxy-aluminium and/or -zirconium to obtain an interlayered smectite, which, when the complex is converted to the metal oxide has greater than 50 percent of its surface area in pores of less than 30 A in diameter, and an interlayer spacing of 6 to 16 A and separating the smectite from the aqueous reaction medium.

10. A process according to Claim 9, which process comprises further heating the complex to convert it to the metal oxide.

11. A process according to Claim 10 wherein the metal complex is converted to the metal oxide by calcining the smectite at a temperature of 200 to 7000C.

12. A process according to Claim 9, 10 or 11, wherein the mixture of the initial smectite and the metal complex is reacted at a temperature of 5 to 2000C from a period of 0.1 to 4 hours.

13. A process according to any one of Claims 9 to 12, wherein the metal complex has the formula Al2+n(OH)3nXe wherein n has the value of 4 to 12 and wherein up to 10% of the aluminum is tetrahedrally coordinated; and X is selected from Cl, Br and NO3.

14. A process according to any one of Claims 9 to 12, wherein the complex is aluminum chlorohydroxide.

15. A process according to any one of Claims 9 to 14, wherein from 0.05 to 2.0 parts by weight of said complex is mixed with each part by weight of said smectite.

16. An interlayered smectite clay produced by a process according to Claim 9.

17. An interlayered smectite clay produced by a process according to Claim 10 or any claim appendant thereto.

18. A hydrocarbon cracking catalyst comprising an interlayered smectite clay according to any of Claims 1 to 8 or Claim 17, and a catalytically active metal of Group VIII of the Periodic Table Ni, Co, W or Mo.

19. A hydrocarbon conversion catalyst comprising an interlayered smectite clay according to any one of Claims 1 to 8 or Claim 17 and an inorganic oxide adsorbent.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. Ads. 35% RH 9.30 Ads. 60% RH 12.48 Ads. 100% RH 19.76 The capacity as a dehydrating agent is comparable to silica gels and zeolites. WHAT WE CLAIM IS:

1. An interlayered smectite clay having an interlayer spacing of 6 to 16 Â, wherein the layers are separated by an inorganic oxide comprising alumina, zirconia or a mixture thereof and wherein the clay has more than 50% of its surface area in pores less than 30 A in diameter.

16. An interlayered smectite clay produced by a process according to Claim 9.