HK1058017B - Aluminum oxide/swellable clay composites and methods of their preparation and use - Google Patents

Description

Alumina/swellable clay composites and methods of making and using the same

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Technical Field

The present invention relates to high pore volume alumina composite particles, methods of making the same, agglomerates and supported catalysts obtained therefrom, and methods of using the catalysts.

Background

The present invention relates to particulate porous alumina particles; a shaped catalyst support obtained therefrom; a support impregnated with various catalytically active metals, metal compounds and/or promoters; and techniques for various applications of such impregnated supports as catalysts.

While the prior art indicates that such particles, supports and catalysts are continually modified and refined to improve their catalytic activity and in some cases have in fact achieved highly desirable activity, there remains a need in the industry for improved catalyst supports and catalysts derived therefrom having enhanced activity and lifetime regulated by an ideal balance of morphological properties.

Alumina is used in a variety of applications including catalyst supports and catalysts for chemical processes, catalyst linings for automotive mufflers, and the like. In many of these applications, it is desirable to add catalytic materials, such as metal ions, finely divided metals, cations, and the like, to the alumina. The content and distribution of these metals on the support, as well as the nature of the support itself, are key factors affecting the overall properties of catalytic activity and lifetime.

Heretofore, alumina for use in catalytic applications has been produced by various methods such as alkoxide hydrolysis of aluminum, precipitation of aluminum oxide from alum, sodium aluminate method, and the like. The latter two processes are costly because the amount of by-products (such as sodium sulfate) actually exceeds the amount of product desired to be obtained (i.e., boehmite). The cost of boehmite is typically 4 times the cost of activated alumina.

In general, although these sources of alumina can be used for catalyst supports, there are some limitations to these applications. This stems from the fact that: for supported catalysts used in chemical reactions, the morphological properties of the support such as surface area, pore volume and pore size distribution of the pores that make up the total volume of the pores are very important. Such properties help to affect the nature and concentration of active catalytic sites, diffusion of reactants to active catalyst sites, diffusion of products away from active sites, and catalyst life.

In addition, the support and its dimensions also affect the mechanical strength, density and reactor packing properties, all of which are important in industrial applications.

Hydrogenation catalysts in petroleum processing represent the majority of alumina supported catalysts in industrial applications. Hydroprocessing applications span many feedstock types and operating conditions but have one or more common goals, namely removal of heteroatom impurities (sulfur, nitrogen, oxygen, metals), increasing the H/C ratio in the product (thereby reducing aromatics, density, and/or carbon residue), cracking carbon bonds to reduce boiling range and average molecular weight.

More particularly, it is well known to use a series of ebullated bed reactors containing a catalyst having improved effectiveness and activity retention in the desulfurization and demetallization of metal containing heavy hydrocarbon streams.

As refining increases the proportion of heavier, lower quality crude oils in the processed feedstock, there is an increasing demand for processes that treat fractions containing high levels of metals, asphaltenes and sulfur.

It is well known that various organometallic compounds and asphaltenes are present in petroleum crude oils and other heavy petroleum hydrocarbon streams, such as petroleum hydrocarbon residual oils, hydrocarbon streams derived from tar sands, and hydrocarbon streams derived from coal. The most common metals in these hydrocarbon streams are nickel, vanadium and iron. Such metals are very detrimental to various petroleum processing operations such as hydrocracking, hydrodesulfurization, and catalytic cracking. These metals and asphaltenes cause plugging of the catalyst bed gaps and reduce catalyst life. Various metals deposited on the catalyst tend to poison or deactivate the catalyst. Moreover, asphaltenes tend to reduce the susceptibility of hydrocarbons to desulfurization. If a catalyst, such as a desulfurization catalyst or a fluidized cracking catalyst, is exposed to a hydrocarbon fraction containing metals and asphaltenes, the catalyst will deactivate rapidly and lead to premature replacement.

While processes for hydrotreating heavy hydrocarbon streams including, but not limited to, heavy crude oil, atmospheric heavy oil, and petroleum hydrocarbon residue are known, it is not uncommon to use fixed bed catalytic processes to convert these feedstocks without significant asphaltene deposition and reactor plugging and to effectively remove metals and other contaminants such as sulfur compounds and nitrogen compounds because the catalysts used generally do not maintain activity and performance.

Thus, certain hydroconversion processes are more efficiently carried out in an ebullating bed. In the ebullated bed, preheated hydrogen and resid enter the bottom of the reactor, where the resid and internally recycled upward stream suspend catalyst particles in the liquid phase. Recent developments have involved the use of powdered catalysts that can be suspended without liquid recirculation. In such systems, a portion of the catalyst is continuously or intermittently removed in a series of cyclones and fresh catalyst is added to maintain activity. Approximately 1 wt% of the total catalyst was replaced per day in the ebullated bed system. Thus, the overall system activity is the weighted average activity of the catalyst ranging from fresh to very old (i.e., deactivated).

In general, it is desirable to design the catalyst to have the highest possible surface area, to provide the highest concentration of catalytic sites and activity. However, within practical limits, surface area is inversely proportional to pore diameter. As the catalyst ages and contaminates, diffusion requires large enough pores, but large pores have lower surface area.

More specifically, formulators are faced with competing factors that govern the balance of morphological properties sought to be imparted to the support or catalyst derived therefrom.

For example, it has been recognized (see, e.g., U.S. patent 4,497,909) that although pores less than 60 angstroms in diameter (in the range referred to herein as the micropore region) have the effect of increasing the number of active centers for certain silica/alumina hydrogenation catalysts, these very same centers are the ones that are first plugged by coke, resulting in a decrease in activity. Similarly, it is also recognized that when more than 10% of the total pore volume in such a catalyst is pores with pore diameters greater than 600 angstroms (in the range generally referred to herein as the macropore region), the mechanical crush strength is reduced as is the catalyst activity. Finally, it has been recognized that for certain silica/alumina catalysts, pores having pore diameters between 150-600 angstroms (approximately in the range referred to herein as the mesoporous region) are desirable at best for acceptable activity and catalyst life.

Thus, while increasing the surface area of the catalyst increases the number of active centers, such an increase in surface area naturally leads to an increase in the proportion of pores in the range of the micropores. As mentioned above, the micropores are easily clogged with coke. In short, the surface area increase and mesopores are at most antagonistic properties.

Furthermore, not only must the surface area be high, but it should also remain stable when exposed to conversion conditions such as high temperature and humidity conditions. Therefore, there is a continuing search for high pore volume, high surface area, hydrothermally stable aluminas suitable for use as catalyst supports. To accommodate this search, the present invention was developed.

U.S. Pat. No. 4,981,825 relates to inorganic metal oxides (e.g. SiO)₂) And clay particles, wherein the oxide particles are substantially isolated from each other by the clay particles. Suitable clays include Laponite^*. The ratio of metal oxide to clay is disclosed as being from 1: 1 to 20: 1 (preferably from 4: 1 to 10: 1). The composition is derived from an inorganic oxide sol having a particle size of 40-800 angstroms (0.004-0.08 microns). The particle size of the final product depends on the particle size in the starting sol, although the final particle size is not reported. It is important that the metal oxide and clay particles are oppositely charged so that they attract each other such that the clay particles inhibit agglomeration of the metal oxide particles. Thus, the clay particles are described as being between the sol particles. The control of the charge on the two different types of particles is determined by the pH of the sol. Inorganic oxidation is induced by adding an acid to control the pH of the inorganic oxide below its isoelectric pointPositive charge on the substance particle. Although suitable inorganic metal oxides are disclosed to also include Al₂O₃However, the use of Al is not provided for₂O₃Examples of the invention were conducted. Therefore, this concept is transferred to Al₂O₃And not without difficulty. For example, Al₂O₃Is an alkaline pH of about 9. However, Al₂O₃The sol is only formed at a pH below about 5. If the pH exceeds about 5, Al₂O₃The sol will precipitate from the dispersion or never form first. In contrast, SiO₂The sol need not be acidic. Therefore, although any point lower than the isoelectric point is referred to SiO₂Sols are acceptable, however, for Al₂O₃This is not the case with sols. On the contrary, it must be in the pH range where alumina sol is formed, far lower than Al₂O₃At a pH value of the isoelectric point. Moreover, the patent does not disclose anything about the porosity properties of the resulting composite, and its extension is only directed to obtaining high surface areas. As mentioned above, surface area and high mesopore pore volume are generally antagonistic properties.

In contrast, the present invention does not use Al either₂O₃The sol begins and does not form during rehydration. The pH at which the composite material of the present invention is formed is too high for sol formation during rehydration, and the starting alumina particles are too large for sol formation.

Another area of technology involving various clay and metal oxide combinations is known as intercalated clays. Intercalated clays are described in U.S. patents 3,803,026, 3,887,454 (see also U.S. patent 3,844,978), 3,892,655 (see also U.S. patent 3,844,979), 4,637,992, 4,761,391 (see also U.S. patent 4,844,790), and 4,995,964. Intercalated clay patents generally share the requirement of using a large clay to sol ratio. Unless freeze-dried, the surface area of the intercalated clay is largely in the micropore range.

U.S. patent 3,803,026 discloses a hydrogel or hydrogel slurry comprising water, a fluorine-containing component andan amorphous cogel comprising oxides or hydroxides of silicon and aluminum. The amorphous cogel further comprises an oxide or hydroxide of at least one element selected from the group consisting of magnesium, zinc, boron, tin, titanium, zirconium, hafnium, thorium, lanthanum, cerium, praseodymium, neodymium and phosphorus, the amorphous cogel being present in the hydrogel or hydrogel slurry in an amount of 5 to 50% by weight. The slurry is subjected to a pH of 6 to 10 and conversion conditions which produce a large amount of crystalline aluminosilicate mineral, preferably containing a large amount of unreacted amorphous co-sol in an intimate mixture. The silica/alumina molar ratio being at least 3: 1, the material obtained being a synthetic layered crystalline clay-type aluminosilicate mineral and the unreacted amorphous cogel being predominantly SiO₂Are present. At column 5, line 39, below, it is disclosed that the resulting aluminosilicate is also broken into particles, comminuted into a powder, said powder being dispersed in a hydrosol or hydrosol slurry, to which components selected from precursor compounds, in particular alumina, are added. The resulting mixture is then dried and activated. Despite the above disclosure, no specific examples using a mixture of silica-aluminate and alumina are disclosed. Therefore, the starting alumina, the final alumina, and the amount of each material used are not disclosed.

Us patent 3,887,454 (and its parent us patent 3,844,978) discloses a layered dioctahedral clay-like mineral (LDCM) which consists of silica, alumina and contains a controlled content of magnesium oxide incorporated into its structure. Preferred clays are montmorillonite and kaolin. At column 6, line 24 below, it is disclosed that the clay material may be combined with inorganic oxide components in general, such as amorphous alumina, among others. In contrast, the composite material of the present invention utilizes crystalline boehmite alumina. Similar disclosures are found in us patents 3,892,655 and 3,844,979, but these patents refer to layered trioctahedral clay-like minerals that contain magnesium oxide as their constituent (LTCM) and are illustrated with clays of the saponite type.

Us patent 4,637,992 is an intercalated clay patent that uses a colloidal suspension of inorganic oxides and adds swellable clay thereto. Although no specific ratio of clay to inorganic oxide is disclosed, it appears that the final material is still directed to a clay-based matrix into which the inorganic oxide is incorporated. Thus, this indicates that the final material contains a large amount of clay, rather than a major amount of alumina and a very small amount of clay as in the present invention. See, for example, U.S. patent 4,637,992 at column 5, line 46 below.

Us patent 4,844,790 (divisional case of us patent 4,761,391) relates to a delaminated clay prepared by reacting a swellable clay with a pillaring agent (pillaring agent) comprising alumina. The ratio of clay to pillaring agent is 0.1: 1 to 10: 1, preferably 1: 1 to 2: 1. However, the main aspect of this patent is alumina-containing clay rather than alumina containing less than 10 wt% clay. It can be concluded that the metal oxide keeps the clay platelet particles apart and provides them with acidity, which is responsible for the catalytic activity of the delaminated clay. The preferred clay is Laponite *.

U.S. Pat. No. 4,995,964 relates to the preparation of a catalyst by reacting an oligomer derived from a rare earth salt, particularly a trivalent rare earth, with a pillaring metal such as Al³⁺To intercalate the swellable clay (hectorite, saponite, montmorillonite). Alumina materials are oligomeric containing aluminum which are used to provide columns of expanded clay. The present invention does not use or produce oligomers of aluminum hydroxide material.

Us patent 4,375,406 discloses a composition containing fibrous clay and pre-fired oxide, which is prepared by the following process: forming a fluid suspension of clay and pre-fired oxide, agitating the suspension to form a co-dispersion, shaping and drying the co-dispersion. The ratio of fibrous clay to pre-fired oxide composition is 20: 1 to 1: 5. These amounts are much higher than the amount of clay used in the present invention. Also, fibrous clays are not within the scope of swellable clays described herein.

Many patents relate to various types of alumina and methods of making it, namely Re 29, 605, SIR H198, and U.S. patents 3,322,495, 3,417,028, 3,773,691, 3,850,849, 3,898,322, 3,974,099, 3,987,155, 4,045,331, 4,069,140, 4,073,718, 4,120,943, 4,175,118, 4,708,945, 5,032,379 and 5,266,300.

More particularly, U.S. patent 3,974,099 relates to silica/alumina hydrogels obtained from sodium silicate and sodium aluminate cogels. The essence of the invention relates to Al₂O₃Precipitation on silica-alumina gel, which stabilizes the hydrothermally passivated cleavage centers. (column 2, line 43 or less). When all the excess sodium aluminate is discharged, the resulting material typically contains about 38.6% alumina. In contrast, the silica used in the present invention is an additive which coats the surface of the alumina/clay composite particles because it is added after the composite is formed.

U.S. patent 4,073,718 discloses an alumina catalyst substrate stabilized with silica on which a cobalt or nickel catalyst is deposited.

U.S. patent 4,708,945 discloses a silica cracking catalyst supported on a boehmite-like surface by compounding porous boehmite particles and reacting the silica with boehmite by steam treatment at a temperature above 500 ℃. Typically 10% silica is used to obtain a surface monolayer of silica to improve thermal stability.

U.S. patent 5,032,379 relates to alumina having a pore volume greater than 0.4ml/g and a pore diameter of 30-200 angstroms. The alumina is prepared by mixing two different types of rehydratable combinable alumina to produce a bimodal pore distribution product.

U.S. Pat. No. 5,266,300 discloses an alumina support prepared by mixing at least two finely divided aluminas, each of which is characterized by at least one pore size (mode) in at least one of the ranges (i)100,000-10,000 angstroms, (ii)10,000-1,000 angstroms, and (iii)1,000-30 angstroms.

U.S. patent 4,791,090 discloses a catalyst support having a double dispersion micropore size distribution. Column 4, line 65 discloses that two sizes of micropores can be formulated by thoroughly mixing different materials with different pore sizes, such as alumina and silica.

U.S. patent 4,497,909 relates to a silica/alumina support containing less than about 40% by weight of silica and at least one noble metal component of group VII of the periodic Table of the elements, and in which catalyst the pores having a diameter of less than 600A represent at least 90% of the total pore volume and, of the pores having a diameter of less than 600A, the pores having a diameter of 150A and 600A represent at least about 40% of the total pore volume.

The following patents disclose various types of clays: U.S. Pat. Nos. 3,586,478, 4,049,780, 4,629,712 and PCT publications WO 93/11069 and WO 94/16996.

The following patents disclose various types of agglomerates, which may be formed from alumina: us patents 3,392,125, 3,630,888, 3,975,510, 4,124,699, 4,276,201 (see also us patent 4,309,278), 4,392,987 and 5,244,648.

U.S. patent 4,276,201 discloses a hydroprocessing catalyst that utilizes a monolith support of alumina, such as beaded alumina, and silica, wherein the silica content is less than 10 weight percent of the support. The surface area of the agglomerate carrier is 350-500m²(ii) in terms of/g. Total Pore Volume (TPV) of 1.0 to 2.5ml/g and less than 0.20ml/g has a diameter greater than 400 angstroms.

Us patent 5,114,895 discloses a layered clay composition uniformly dispersed in an inorganic oxide matrix such that the clay layers are completely surrounded by the inorganic oxide matrix. The inorganic oxide matrix is selected from aluminum oxide, titanium dioxide, silicon dioxide, zirconium dioxide, and P₂O₅And mixtures thereof. Suitable clays include bentonite, sepiolite, Laponite^TMVermiculite, montmorillonite, kaolin, palygorskite (attapulgus), hectorite, chlorite, beidellite, saponite, and nontronite. In order to obtain a homogeneous dispersion of the clay in the inorganic oxide matrix, precursors of the inorganic oxide are dispersed in the form of a sol or hydrosol and gelled in the presence of the clay. Although clay contents of 5 to 70 wt.% are broadly disclosed, the preferred ranges areIt is the examples that at least 30% by weight of clay was used. Furthermore, no porosity properties or resulting products are disclosed.

Us patent 4,159,969 discloses a method of making alumina agglomerates by contacting an aqueous alumina gel with a water-immiscible organic liquid, wherein the amount of liquid is a function of the water in the aqueous alumina gel. Clays such as bentonite or kaolin may be added to the alumina during or after gelation in an amount sufficient to increase the strength of the agglomerates. No specific clay amounts are disclosed and kaolin is not a swellable clay. No example uses clay.

U.S. patent 3,630,888 discloses a catalyst having a structure in which channels having a diameter of about 100-1000 angstrom units account for 10-40% of the total pore volume and in which channels having a diameter greater than 1000 angstrom units account for about 10-40% of the total pore volume, with the remainder of the pore volume containing 20-80% micropores having a diameter less than 100 angstrom.

The following patents disclose various hydroprocessing operations and catalysts used therein: U.S. Pat. Nos. 3,887,455, 4,657,665, 4,886,594, PCT publication WO 95/31280.

Summary of The Invention

The present invention is based on the following findings: when activated alumina is dispersed and subjected to a rehydration process in the presence of a controlled amount of dispersed swellable clay, the resulting composite particles exhibit and maintain a high surface area relative to the absence of clay, and at the same time have a high pore volume and a pore size in the mesoporous region of up to several values. These properties are substantially preserved in agglomerates, such as shaped extrudates, which are derived from the composite particles before and after impregnation with the catalytically active metal component (e.g., for hydroprocessing operations). Furthermore, the incorporation of swellable clay improves the hydrothermal stability of the composite particles.

The improvement in hydrothermal stability increases the overall economic efficiency of the process in which it is used, while the shift to higher mesopore ceiling values increases the activity of the supported catalyst derived from the composite particles. Higher pore maxima improve hydrocarbon accessibility and reduce the likelihood of pore plugging due to coke or metal deposition.

High pore volume alumina is typically prepared by azeotroping with an alcohol to remove water prior to drying. The use of alcohol reduces the surface tension of the water, which in turn reduces the shrinkage of the pores during drying. This technique is very expensive and not environmentally friendly. Alumina with high Average Pore Diameter (APD) is typically prepared by sintering at high temperatures. Although sintering increases the APD of the unsintered material, it of course reduces the surface area relative to the unsintered material. Therefore, to achieve higher APDs, surface area must be sacrificed. It has been found that not only can the mesopore maximum be shifted towards larger pores prior to sintering, but it is also believed that upon exposure to high temperatures (typically accompanied by sintering without clay) a smaller shrinkage of the pore diameter will occur. Thus, since it is possible to start with a higher maximum pore value and less shrinkage occurs from the higher maximum pore value, a high surface area, high pore volume product can be obtained in a less costly and environmentally friendly manner, e.g., the alcohol azeotrope can be eliminated and the heating temperature required for alumina can be reduced.

Accordingly, in one aspect of the present invention there is provided a porous composite particle comprising an alumina component and a swellable clay component well dispersed in the alumina component, wherein, in the composite particle:

(A) the alumina component comprises at least 75% by weight alumina, at least 5% by weight of which is in the form of crystalline boehmite, gamma-alumina derived from crystalline boehmite, or a mixture thereof.

(B) The swellable clay component is dispersible prior to incorporation into the composite particles and is present in the composite particles in an amount (a) less than about 10 weight percent based on the total weight of the alumina component and the swellable clay component, (b) effective to increase at least one of the hydrothermal stability, nitrogen pore volume, and nitrogen mesopore mode relative to the corresponding hydrothermal stability, pore volume, and mesopore mode of the alumina component without the swellable clay; and

(C) the composite particles have an average particle size of about 0.1 to about 100 microns.

In another aspect of the present invention, there is provided a method of manufacturing porous composite particles, comprising:

(A) forming a non-colloidal dispersion in a liquid dispersion medium comprising at least one alumina component comprising at least 75% by weight active alumina and at least one swellable clay component;

(B) rehydrating the active alumina in the alumina component in the presence of the dispersed swellable clay to convert at least 5 wt.% of the active alumina to crystalline boehmite and form composite particles comprising an effective amount of swellable clay well dispersed in the alumina component, the effective amount of swellable clay being (i) less than 10 wt.% based on the total weight of the alumina component and swellable clay, and (ii) effective to increase at least one of the hydrothermal stability, nitrogen pore volume, and nitrogen mesopore mode maxima of the composite particles relative to the corresponding hydrothermal stability, pore volume, and mesopore mode maxima of the alumina component without the swellable clay;

(C) recovering composite particles from the dispersion; and

(D) optionally calcining the recovered composite particles at about 250 ℃ and 1000 ℃ for a time period of about 0.15 to about 3 hours.

In another aspect of the invention, there is provided an agglomerate of the above particles.

In another aspect of the invention, there is provided a supported catalyst obtained from the aforesaid agglomerates.

In another aspect of the invention, a process for hydrotreating a petroleum feedstock using the aforesaid agglomerates as a hydrotreating catalyst is provided.

Brief Description of Drawings

The following table summarizes FIGS. 1-24, which are graphs from the examples. Relevant information regarding these figures, including the corresponding test, example or comparative example numbers, X-axis, Y-axis and legend are provided in the following table

20	60-61	Example 19	Hg method pore diameter *	Hg dV/dLogD	Test 61(CAX-1) - - - - - - - -test 60(AX-1)	9450	FIG. 1 shows a schematic view of a
								21	62，64，66，68	Example 20 example 21 comparative example 4	Hg method pore diameter *	dV/dLogD	Test 68(EMCAX-1) - - - - - -test 62(EMAX-1) - - - - - - -, test 64(EMAX-2) - -test 66(EMAX-3)	9450	FIG. 2
22	70-72	Example 23 example 24 comparative example 5	Hg method pore diameter *	HgdV/dLogD	Test 72- -test 71- -test 70	9450	FIG. 6
								23	76-77	Example 24 comparative example 7	Catalyst life, bbl/lb.	Conversion rate%	Experiment 76(EMAX-1) A experiment 77(EMCAX-1)	9450	FIG. 9.1
24	78-80	Example 27 example 28 comparative example 8	Catalyst life, bbl/lb.	Conversion rate%	Experiment 78(EMAX-2) ■ experiment 79(EMAX-3) ● experiment 80(EMCAX-1)	9450	FIG. 10.1
								dV/d log d is the differential L of pore volume (ml/g) versus log (pore diameter) Laponite*(synthetic hectorite) CK ═ calcined Kaolin GL ═ Gelwhite-L montmorillonite clay SA ═ surface area

Detailed description of the preferred embodiments

The term "microporous" as used herein refers to pores having a diameter of less than 100 angstroms.

The term "mesoporous" as used herein refers to pores having a diameter of 100-500 angstroms.

The term "macroporous" as used herein refers to pores having a diameter greater than 500 angstroms.

The term "most probable pore value" as used herein refers to the pore diameter corresponding to the maximum peak when the logarithmic differential of the nitrogen or mercury intrusion expressed in ml/g is plotted as a function of the differential of the logarithm of the pore diameter.

The term "total pore volume" as used herein refers to the cumulative volume of all pores in ml/g as determined by nitrogen desorption or mercury intrusion. More specifically, for alumina particles that have not coalesced (e.g., by extrusion), the pore diameter distribution and pore volume are calculated with reference to a nitrogen desorption isotherm (assuming a circular pore) obtained by a B.E.T. technique such as that described in S.Brunauer, P.Emmett, and E.Teller, Journal of American chemical Society, 60, pp 209-.

With regard to alumina particles which have coalesced, for example, to be shaped into extrudates, the pore diameter distribution is calculated by means of the following formula and in accordance with mercury porosimetry using mercury pressures of 1-2000 bar (as described in h.l.ritter and l.c.drain in Industrial and Engineering Chemistry, Analytical Edition 17, 787 (1945)):

equation 1

However, the surface area of the composite particles and agglomerates was measured by nitrogen desorption.

The total nitrogen volume of the sample is the sum of the nitrogen method pore volumes measured by the nitrogen desorption method described above. Similarly, the mercury total pore volume of the sample is the sum of the mercury pore volumes measured by mercury intrusion as described above using a contact angle of 130 °, a 485 dyne/cm and a Hg density of 13.5335 g/ml.

All morphological properties relating to weight such as pore volume (ml/g) or surface area (m)²/g) was normalized to metal Free Basis (Metals Free Basis) as defined in equation 4 described in example 20.

All new surface areas were measured on samples that had been dried and then calcined in air at 537.8 ℃ for 2 hours.

Bulk density was measured by rapidly transferring the sample powder into a measuring cylinder which began to overflow when it reached exactly 100 ml. At this point no further powder was added. The powder addition rate should prevent settling in the graduated cylinder. The weight of the powder was divided by 100ml to give the density.

All particle size and particle size distribution measurements described herein were determined by a Mastersizer device from Malvern, which operates according to the principles of laser diffraction and is well known to those familiar with the art of small particle analysis.

The alumina component mixed with the swellable clay component typically contains at least 75, preferably at least 80 (e.g., at least 85), and most preferably at least 90 (e.g., at least 95) wt.% active alumina, which can typically be from about 75 to about 100, preferably from about 80 to about 100, and most preferably from about 90 to about 100 wt.% active alumina. Activated alumina can be prepared by various methods. For example, alumina trihydrate precipitated in the bayer process may be ground and flash-fired. The activated aluminas mentioned herein are characterized by having a poorly crystalline and/or amorphous structure.

For the purposes of the above process, the expression "alumina of poor crystalline structure" is understood to mean an alumina which has been subjected to X-ray analysis to exhibit only one or few diffraction lines corresponding to the crystalline phases of the low-temperature phase-transition alumina and which contains predominantly chi, rho, eta, gamma and pseudo-gamma phases and mixtures thereof.

The expression "alumina of amorphous structure" means an alumina which is such that its X-ray analysis does not give any characteristic line of highly (or predominantly) crystalline phases.

Activated alumina as used herein is typically obtained by the rapid dehydration of aluminum hydroxides such as bayerite, gibbsite or gibbsite and nordstrandite or aluminum hydroxides such as boehmite and diaspore. The hydrolysis may be carried out in any suitable apparatus and using a hot gas stream. The temperature of the gas entering the apparatus is typically about 400 c to 1,200 c and the contact time of the hydroxide or hydroxide compound with the hot gas stream is typically a fraction of a second and 4 to 5 seconds.

The resulting product may contain small amounts, such as traces of boehmite, gibbsite, gamma, alpha, delta, and other crystalline alumina structures.

The resulting activated alumina typically had a weight loss of about 4 to 12 wt% when heated at 538 c for 1 hour.

The specific surface area of the activated alumina obtained by rapid dehydration of hydroxide or oxyhydroxide is generally about 50 to 400m, as measured by the conventional BET method²In terms of a/g, the particle diameter is generally from 0.1 to 300 microns, preferably from 1 to 120 microns, and the average particle diameter is generally greater than 1 micron, preferably from about 5 to about 20, more preferablyAbout 5 to about 15 microns. The weight loss on ignition, determined by calcination at 1,000 ℃ is generally between 3 and 15%, which corresponds to H₂O/Al₂O₃The molar ratio is about 0.17 to about 1.0.

In a preferred embodiment, activated alumina from the rapid dehydration of bayer hydrate (gibbsite), which is a readily available and inexpensive commercial aluminum hydroxide, is used. Activated aluminas of this type are well known to those skilled in the art and processes for their preparation have been described, for example, in U.S. Pat. Nos. 2,915,365, 3,222,129, 4,579,839, and preferably 4,051,072, column 3, line 6 to column 4, line 7, the contents of which are incorporated herein by reference.

The activated alumina used may be used or treated to have a sodium hydroxide content (expressed as Na)₂O) less than 1,000 ppm.

More specifically, composite particles made with silicates or certain clays, such as synthetic lithium manganese montmorillonite, typically contain Na₂O, which can cause the alumina to sinter at high temperatures. Such sintering reduces the surface area. To exclude such sintering, it is preferred to wash the alumina to remove Na in the form of a salt₂And O. More specifically, it is still preferred to slurry alumina in water for 15 minutes, which contains about 0.05 parts by weight aluminum sulfate (A/S), about 1 part by weight alumina, and 5 parts by weight water. The slurry was then filtered, washed at least once with water to remove salts and dried in an oven. The washing may be with clay or any other material that may contain Na₂Before or after the other components of O are contacted. The activated alumina used may or may not be milled, but is preferably milled to facilitate dispersion in or with the swellable clay slurry described below.

Suitable activated alumina powder starting materials are commercially available from the Aluminum Company of America under the grade designations CP-3, CP-1, CP-5, CP-7, and CP-100. It is also commercially available from Porocel (Little Rock, Arkansas.) under the name AP-15.

All activated aluminas suitable for use in the alumina component of the present invention are rehydratable and form hydroxyl bonds upon contact with water. The present invention describes the distinction between the phenomenon of rehydration, i.e. the process steps involved in subjecting activated alumina to water and high temperature induced chemical changes, and the process of rehydration, i.e. the induction of rehydration.

The rehydration phenomenon is believed to represent the chemical and physical state of the activated alumina that has been converted to crystalline boehmite. However, the change in state from activated alumina to boehmite need not be complete for the entire sample being worked on during rehydration. For example, depending on the conditions of the rehydration process, it is also possible that only the outer shell of activated alumina particles or filter cake is converted to boehmite while the remaining inner portion remains activated alumina or some form of alumina other than boehmite or activated alumina. Thus, although "rehydrated alumina" is chemically synonymous with boehmite, alumina resulting from the rehydration of activated alumina includes boehmite, activated alumina, and any alumina by-products that may be formed during rehydration other than boehmite. Similarly, rehydration is meant to include the controlled process steps of adding activated alumina to water under conditions such as elevated temperatures, as described below.

The swellable clay component comprises any 2: 1 layered silicate clay capable of swelling and dispersing and mixtures thereof. Swelling clays are swellable clays whose platelet particles are held together by weak van der waals forces and have a particular shape or morphology. Such clays include smectite clays and their ion exchange (e.g., Na)⁺、Li⁺) And (3) derivatives. In general, alkali metal ion-exchanged forms are preferred because of their ability to enhance swelling and dispersion. Dispersible 2: 1 layered silicates such as tetrasilicic mica (tetrasilicic mica) and taeniolite are also useful.

More specifically, montmorillonite is a 2: 1 clay mineral that carries a lattice charge and characteristically swells when dissolved with water and alcohol (most notably ethylene glycol and glycerol). These minerals comprise a layer represented by the general formula:

(M₈)^IV(M′_x)^VIO₂₀(OH，F)₄

where IV represents an ion coordinated to four other ions, VI represents an ion coordinated to six other ions, and x may be 4 or 6. M is usually Si⁴⁺、Al³⁺And/or Fe³⁺But also includes several other four-coordinate ions such as P⁵⁺、B³⁺、Ge⁴⁺、Be²⁺And the like. M' is usually Al³⁺Or Mg²⁺But also includes many possible hexacoordinated ions such as Fe³⁺、Fe²⁺、Ni²⁺、Co²⁺、Li⁺And the like. The charge deficit resulting from the various substitutions into these four-and six-coordinate cationic positions can be balanced by one or several cations located between the building blocks. Water may also be occluded between these structural units, either bound to the structure itself or to the cations as a hydration layer. The above structural units have a repeat distance of about 9-12 angstroms when dehydrated (dehydroxylated) as measured by X-ray diffraction. Commercially available natural smectites include montmorillonite (bentonite), beidellite, hectorite, saponite, sauconite, and nontronite. Also commercially available are synthetic smectites such as LAPONITE^*A synthetic hectorite from Laporte Industries Limited.

Montmorillonite is divided into two classes: dioctahedral and trioctahedral, the difference being the number of octahedra occupied in the central layer. This in turn is related to the valence state of the cation in the central layer.

Dioctahedral smectites have a trivalent central cation, so only two thirds of the octahedral sites are occupied, whereas trioctahedral smectites have a divalent central cation, in which all the octahedral sites are occupied. Dioctahedral smectites include montmorillonite, beidellite and nontronite, where, for example, montmorillonite has the octahedral cation (M') aluminum, and other cations such as magnesium are also present. Trioctahedral montmorillonite, which is preferred, includes hectorite and saponite and their synthetic forms, wherein, for example, hectorite contains magnesium as the octahedral cation (M'), and lithium is also present.

The smectites most advantageously used in the preparation of the composition of the invention are trioctahedral smectite clays having a lath-like morphology. However, it is also possible to use trioctahedral smectites in platelet-shaped or mixed stripe-and platelet-shaped morphology. Examples of suitable trioctahedral smectite clays are natural bentonites, and preferred are natural hectorites and synthetic hectorites.

The most preferred swelling clay for use as the swellable clay component is synthetic hectorite. The processes for preparing synthetic hectorites are well known and are described, for example, in U.S. patents 3,803,026, 3,844,979, 3,887,454, 3,892,655 and 4,049,780, the contents of which are incorporated herein by reference. A typical example of a synthetic hectorite is Laponite^*RD。Laponite^*RD clay is a filter-pressed, tray-dried and pin-milled product. Laponite (Laponite)^*The platelet particles of RD clay consist of two silica layers surrounding one octahedrally coordinated magnesium layer (and lithium substitution present in this layer). Laponite (Laponite)^*RD clays and other Laponites are manufactured and sold by Laporte Inorganics, a division of LaporteIndustries Limited. Laponite (Laponite)^*Typical analytical and physical properties of the RD clay are set forth in table 1 below.

TABLE 1

CheLaponite^*Chemical composition of RD

Composition (I)	By weight%
		SiO2	59-60
MgO	27-29
		Li2O	0.7-0.9
Na2O	2.2-3.5
		Loss on ignition	8-10
Physical Properties
		Appearance of the product	White powder
pH (2% suspension)	9.8
		Bulk Density (kg/m)2)	1000
Surface area (N)2Adsorption)	370m2/g
		Sieve analysis% < 250 μm	98
Water content, wt%	10

To prepare the composite particles of the present invention, the non-colloidal activated alumina is at least partially rehydrated in the presence of the dispersed swellable clay.

The rehydration process of alumina will eventually occur naturally in the presence of water at room temperature, but this takes a longer time. Therefore, the rehydration process is preferably performed at an elevated temperature of at least about 50 ℃ to increase the speed of the hydration process. The rehydration process is conveniently carried out by simply refluxing an aqueous slurry of the activated alumina for a period of time, typically from about 1 to about 72 hours, preferably from about 2 to about 48 hours, most preferably from about 3 to about 24 hours.

Rehydration conditions are controlled to obtain a high pore volume product. Thus, the rehydration conditions are controlled such that generally at least 5, preferably at least 10, and most preferably at least 15 weight percent of the activated alumina is converted to boehmite, and the boehmite content in the alumina resulting from the activated alumina rehydration process is generally from about 5 to about 100 (e.g., 30 to 100), preferably from about 10 to about 100 (e.g., 50 to 100), and most preferably from about 15 to about 100 (e.g., 75 to 100) weight percent based on the weight of the alumina. An undesirable by-product of the boehmite formation process is bayerite, which is alumina trihydrate formed when the pH of water exceeds about 10.

In view of the original activated alumina content of the alumina component and the extent of conversion of the activated alumina to crystalline boehmite, the alumina component of the composite particles desirably comprises (a) generally at least 75, preferably at least 80 (e.g., at least 85), and most preferably at least 90 (e.g., at least 95) wt.% alumina, preferably alumina derived from the activated alumina rehydration process, and (B) generally at least 3.75, preferably at least 7.5, and most preferably at least 10 wt.% of the alumina component is crystalline boehmite which may generally have a crystalline boehmite content of from about 3.75 to about 100 (e.g., 40 to 100), preferably from about 7.5 to about 100 (e.g., 75 to 100), and most preferably from about 10 to about 100 (e.g., 90 to 100) wt.%, based on the weight of the alumina component. Similarly, the weight ratio of crystalline boehmite to swellable clay in the composite particles is generally from about 4: 1 to about 99: 1, preferably from about 9: 1 to about 50: 1, and most preferably from about 15: 1 to about 50: 1.

The crystal size (as measured by the method described in example 1) is generally less than about 110 (e.g., less than about 100) angstroms, and is generally from about 55 to about 110, preferably from about 60 to about 100, and most preferably from about 65 to about 95 angstroms.

At a pH of about 9 (e.g., 7-10), boehmite formation is maximized. Thus, a buffer solution such as sodium gluconate may be added to stabilize the pH at about 9, but such additives may have the adverse effect of reducing the boehmite crystal size, which in turn tends to reduce the total pore volume. Therefore, it is preferable not to use a buffer solution. Indeed, one of the advantages of swellable clays is that it is a natural buffer solution with a pH of about 9 and inhibits rehydration to bayerite.

As mentioned above, the rehydration of the active alumina in the alumina component must be carried out in the presence of dispersed swellable clay. Without wishing to be bound by any particular theory, it is believed that the highly dispersed swellable clay is entrapped within the growing boehmite crystals and creates inter-crystalline voids by maintaining the separation of the crystallites, thereby increasing pore volume without reducing surface area. It is believed that for this reason, the smaller the size of the swellable clay particles and the higher the degree of dispersion of the clay particles in the slurry, the greater the variation in the most probable value of the porosity in the mesoporous range of the composite particles. Rehydration of the alumina is neither initiated with the alumina sol, nor is the activated alumina converted to alumina sol during rehydration. Furthermore, improved pore properties cannot be obtained if the swellable clay is merely mixed with preformed boehmite, rather than forming boehmite, for example, by rehydration of activated alumina in the presence of clay.

In a preferred embodiment, the alumina component may be pre-milled, either alone or in combination with the swellable clay, prior to rehydration of the activated alumina therein. The pre-milling may be carried out in a wet mill, such as a DRAIS, PREMIER or other type of sand mill or ball mill.

However, if the pre-milling is carried out in the absence of the desired swellable clay, it must be carried out at a temperature sufficiently low to avoid premature rehydration prior to contact with the dispersed swellable clay.

The pre-milling of the alumina component is typically carried out at room temperature for a time sufficient to reduce the average particle size to typically about 0.1 to about 8 (e.g., 1 to 8), preferably about 0.1 to about 5 (e.g., 1 to 5), and most preferably about 0.1 to about 2.5 microns.

The swellable clay component is dispersed in a slurry, typically an aqueous slurry, the dispersion conditions preferably being those that maximize dispersancy. Certain swellable clays are more dispersible than others. If the dispersion obtained during contact with the alumina being rehydrated is poor, the desired effect on the pore properties of the alumina cannot be obtained or cannot be maximized. Therefore, it may be desirable to take steps to induce suitable dispersion, such as milling, total volatiles control, and/or use of dispersion aids such as tetrasodium pyrophosphate (Na)₄P₂O₇). To deionized water or containing Na₄P₂O₇The water is slowly added with clay to reduce divalent cations such as Ca⁺²And Mg⁺²In an amount that helps to disperse the clay. If the clay is added to a high shear mixer such as a COWLES, MYERS or SILVERSON mixer, the time required to disperse the clay is reduced. Satisfactory dispersion can be obtained with a paddle type blender, especially when using a tank with baffles.

Obtaining a suitable degree of dispersion is difficult to assess, but as a general rule, the greater the transparency of the suspension medium, the better the dispersion, and in the case of synthetic hectorite, a completely transparent medium is most preferred. This typically occurs when the clay particles are predominantly of a colloidal size of less than about 1 micron.

Thus, the dispersion of the swellable clay may be accomplished by mixing the clay with water, preferably under high shear conditions, typically for about 5 to about 60, preferably about 10 to about 30 minutes. The temperature at which the dispersion is formed is not critical and is typically from about 10 ℃ to about 60 ℃. It is important that the water is free of other minerals that affect clay dispersibility, for example, deionized water is preferred.

The degree of dispersion is enhanced if the total volatiles content of the starting clay is generally at least 6%, preferably at least 8% and generally from about 6 to about 30, preferably from about 10 to about 20, most preferably from about 12 to about 18% by weight thereof.

The amount of clay imparted to the final composite particles is selected to be effective to increase at least one of the total nitrogen process pore volume, hydrothermal stability (as defined below), and/or nitrogen process mesopore mode number relative to the corresponding pore volume, hydrothermal stability (as defined below), and mesopore mode number of the alumina component without the swellable clay. More specifically, the maximum value of mesopores is typically at least 10%, preferably at least 30%, and most preferably at least 50% higher than the corresponding maximum value of mesopores obtained without the swellable clay.

Suitable effective amounts of swellable clay are generally less than about 10 (e.g., less than about 9), preferably less than about 8, and most preferably less than about 6 weight percent, and generally from about 1 to about 9 (e.g., from about 1 to about 8), preferably from about 2 to about 7, and most preferably from about 2 to about 5 weight percent, based on the total weight of the alumina component and the swellable clay component.

When the clay content of the composite particles is increased by more than 1% by weight, not only does the mesopore pore volume increase until it reaches 6% by weight of swellable clay, and then the mesopore pore volume decreases, but also the surface area. In addition, the presence of clay increases the hydrothermal stability of the composite particles, up to a clay content of about 10% by weight, after which the hydrothermal stability of the composition particles begins to decrease.

It is evident from the above discussion that rehydration of alumina in the presence of dispersed swellable clay can be carried out in a variety of ways.

For example, two separately prepared slurries (dispersions) containing a swellable clay component and a non-colloidal alumina component, respectively, may be mixed, or preferably one slurry may be directly prepared by first adding either of the two components to water or simultaneously mixing the clay and alumina components with water.

However, if two separate slurries are prepared, care should be taken to ensure that rehydration of the activated alumina in the alumina component does not occur prematurely before contact with the dispersed clay.

The solids content of the slurry comprising the alumina component and the clay component is controlled to generally range from about 2 to about 30, preferably from about 4 to about 25, and more preferably from about 5 to about 25 weight percent based on the weight of the slurry. When the weight percentage of clay is 4 or less than 4, the mesopores typically increase in size with decreasing solids content in these ranges and vice versa.

Thus, absent pre-milling of the clay component and the alumina component, it is preferred to prepare a slurry of the dispersible clay component in dispersed form, to which the alumina component is added, and then subjecting the mixture to shear action at elevated temperature as described above, in order to disperse the swellable oxide well and rehydrate the alumina.

In a preferred embodiment, the dispersed clay component is pre-milled in admixture with the alumina component prior to alumina rehydration. Thus, in this embodiment, a slurry of the swellable clay component is prepared under agitation until fully dispersed. To this clay dispersion is added an appropriate amount of an alumina component and the resulting composition is wet milled, preferably vigorously at room temperature, for example in a DRAIS mill, typically for a period of about 0.1 to about 3, preferably about 0.5 to 2.0 minutes. The pre-milled slurry was then refluxed to rehydrate the alumina as described above.

It has been found that pre-grinding results in an increase in the hydrothermal stability of the composition, but only a slight drift to smaller pores.

More specifically, the hydrothermal stability of the alumina composite particles was evaluated by comparing the fresh and steamed surface areas, as described below.

The BET nitrogen surface area was determined by calcining in air at 537.8 ℃ (1000 ° F) for 2 hours and is referred to as the fresh surface area. The uncalcined sample was then exposed to air containing about 20% by volume steam at 800 ℃ under autogenous pressure for 4 hours, whereupon the BET surface area was determined and referred to as the steamed surface area.

A comparison was then made between fresh and steamed surface areas. The smaller the difference between fresh and steamed surface area, the higher the hydrothermal stability.

Once rehydration of the activated alumina is complete in the presence of the swellable clay component, the resulting composite particles can be recovered, thermally activated under the same conditions as described below for agglomeration or used directly for catalyst application.

Preferably, the composite particles are recovered and dried and optionally sieved. Suitable particle sizes are generally from about 1 to about 150 (e.g., from 1 to about 100), preferably from about 2 to about 60, and most preferably from about 2 to about 50 microns.

It is recovered by filtration, evaporation, centrifugation, or the like. The slurry may also be spray dried to complete recovery.

The resulting composite particles generally have a nitrogen BET surface area (on a metal-free basis) of at least about 200, preferably at least about 240, and most preferably at least about 260m²The surface area may generally be from about 200 to about 400, preferably from about 240 to about 350, and most preferably from about 240 to about 300 m/g²(ii) in terms of/g. Surface area measurements were made on samples that had been dried at 138 ℃ (280 ° F) for 8 hours and calcined at 537.8 ℃ (1000 ° F) for 2 hours.

The composite particles typically have an average nitrogen method pore diameter of from about 60 to about 400 (e.g., from 60 to about 300), preferably from about 70 to about 275, and most preferably from about 80 to 250 angstroms.

The total nitrogen process pore volume (on a metal-free basis) of the composite particles is from about 0.5 to about 2.0, preferably from about 0.6 to about 1.8, and most preferably from about 0.7 to about 1.6 ml/g. The samples were dried at 138 ℃ (280 ° F) and then calcined at 537.8 ℃ for 2 hours before testing the pore diameter or pore volume.

One advantage of the present invention is that swellable clays shift the mesopore pore size toward higher pore diameters at most and still maintain a high surface area as described above relative to the absence of swellable clays.

Even more importantly, the present invention provides a mechanism to control the size of the pores to the most probable value by varying the preparation conditions, especially the clay content in the composite and the solids content in the rehydrated slurry. More specifically, decreasing the clay content from the optimum and/or increasing the solids content of the rehydrated slurry both decrease the pore maximum.

Thus, the composite particles typically have a macropore content (i.e., the percentage of those pores in the range of macropores in the total pore volume by the nitrogen process) of not greater than about 40, preferably not greater than about 30, and most preferably not greater than about 25% of the total pore volume, which is typically from about 5 to about 50, preferably from about 10 to about 40, and most preferably from about 10 to about 30% of the total pore volume.

The nitrogen process pore content is generally from about 20 to about 90, preferably from about 30 to about 80, and most preferably from about 40 to about 70 percent of the total pore volume. Moreover, typically at least about 40, preferably at least about 50, and most preferably at least about 60 percent of the pores in the mesopore range typically have a pore diameter of from about 100 to about 400, preferably about 100 and 350, and most preferably about 125 and 300 angstroms.

The nitrogen-process mesopore content of the formed composite particles is also desirably of a nitrogen-process pore maximum value, preferably only a single pore maximum value (unimodal), which is generally from about 60 to about 400 (e.g., 60 to about 300), preferably from about 70 to 275, and most preferably from about 80 to about 250 angstroms.

The composite particles typically have a nitrogen-method micropore content of no greater than about 80, preferably no greater than about 60, and most preferably no greater than about 50 percent of the total pore volume, which is typically from about 80 to about 5, preferably from about 60 to about 10, and most preferably from about 30 to about 15 percent of the total pore volume.

It has also been found that the hydrothermal stability of the composite particles can be further improved by incorporating silicates therein.

Suitable silicates include alkali and alkaline earth metal silicates, with sodium silicate being most preferred. Less soluble silicates such as natural or synthetic clays or silica gels may also improve stability. Examples of such clays are kaolinite, montmorillonite and hectorite. Calcined clays can also improve hydrothermal stability.

Silicate may be added to the alumina and swellable clay components prior to rehydration, but it is preferred that the addition of silicate be done after rehydration (thermal aging) in order to maximize hydrothermal stability induction and achieve high pore volume and high average pore diameter. The addition of soluble silicate prior to alumina rehydration tends to produce small pores that are less stable than large pores (i.e., coalesce into larger pores upon heating), thereby reducing the total pore volume. The silicate may be added after thermal aging for several hours after the pore size distribution is determined.

The amount of silicate effective to improve the hydrothermal stability of the composite particles described herein is generally from about 0.1 to about 40, preferably from about 1 to about 20, most preferably from about 2 to about 10 weight percent based on the total weight of the silicate, the alumina component, and the swellable clay component.

Without wishing to be bound by any particular theory, it is believed that the added silicate is distinguishable from the silicate in the clay, since it is believed that the former can migrate freely to the alumina during rehydration while the silicate of the clay remains largely intact during rehydration. However, a partial effect of clay on pore size and stability may be attributed to silicate migration from clay to alumina during rehydration.

Although the composite alumina particles can be used directly as a support, it is more convenient for such use to agglomerate the particles.

Such alumina agglomerates can be used as catalysts or catalyst supports in any reaction requiring a specific pore structure and very high mechanical, thermal and hydrothermal properties. Thus, the agglomerates of the invention may find particular utility as catalyst supports in the treatment of exhaust gases produced by internal combustion engines and in the treatment of hydrogen gas from petroleum products, such as hydrodesulfurization, hydrodemetallization and hydrodenitrogenation. They can also be used in the recovery of sulfur compounds (Claus catalysis); catalyst supports for the dehydrogenation, reforming, steam reforming, dehydrohalogenation, hydrocracking, hydrogenation, dehydrogenation and dehydrocyclization, and oxidation and reduction reactions of hydrocarbons or other organic compounds. They can also be used as additives for fluid cracking catalysts, in particular for increasing the pore volume and the mesopore or macropore porosity.

They may also be used as catalysts for reactions normally catalysed by alumina, such as hydrocracking and isomerisation reactions.

Thus, the beneficial properties of increasing the mesopore content and hydrothermal stability of the composite particles at higher surface areas are transferred to the agglomerates.

The term "agglomerates" refers to the products of bringing particles together by various physico-chemical forces.

More specifically, each agglomerate is composed of a number of adjacent constituent primary particles that have been sized as described above, preferably bonded or connected at their points of contact.

Thus, the agglomerates of the present invention may exhibit a higher macropore content than the constituent primary particles because of the interparticle gaps that exist between the constituent composite alumina particles.

However, the agglomerated particles still retain a higher mesopore maximum value.

Thus, after drying at 121 ℃ (250 ° F) for 8 hours and calcining at 537.8 ℃ (1000 ° F) for 1 hour, the briquettes of the present invention are characterized by the following properties (on a metal-free basis):

(1) a nitrogen-method surface area of at least about 100, preferably at least about 150, and most preferablyAt least about 200m²Per gram, the surface area is generally from about 100 to about 400, preferably from about 125 to about 375, most preferably from about 150 to about 350m²/g，

(2) The agglomerates typically have a bulk density of at least about 0.30, preferably at least about 0.35, and most preferably at least about 0.40g/ml, which bulk density may typically range from about 0.30 to about 1, preferably from about 0.35 to about 0.95, and most preferably from about 0.40 to about 0.90g/ml,

(3) the mercury method total pore volume is from about 0.40 to about 2.0, preferably from about 0.5 to about 1.8, most preferably from about 0.6 to about 1.5ml/g,

(4) the macropore content (i.e., pores falling within the macropore range in the total pore volume) is generally not greater than about 40, preferably not greater than about 30, and most preferably not greater than about 20% of the total pore volume, which is generally from about 5 to about 40, preferably from about 10 to about 35, and most preferably from about 15 to about 30,

(5) the mesopore content is generally from about 15 to about 95, preferably from about 20 to about 90, and most preferably from about 30 to about 80 percent of the total pore volume. Also, typically at least about 30, preferably at least about 40, and most preferably at least about 50 percent of the pores in the mesopore range have a pore diameter of typically about 80 to about 400 (e.g., 100-,

(6) the average agglomerate particle diameter is generally from about 0.5 to about 5, preferably from about 0.6 to about 2, and most preferably from about 0.8 to about 1.5 mm.

The mesopore content of the calcined agglomerate particles is also desirably of a maximum value of mesopore porosity of generally from about 60 to about 400 (e.g., from 60 to about 300), preferably from about 65 to about 275, and most preferably from about 70 to about 250 angstroms.

In addition, the agglomerates can be mixed with other conventional aluminas to produce a pore size distribution having two or more of the most probable values in the mesopore range. Each alumina provides a mesopore maximum at its unique characteristic location. Mixtures of two or more aluminas prepared with swellable clays can also be expected to have varying pore maxima.

The agglomeration of the alumina composite particles is carried out according to methods well known in the art, in particular by granulation, extrusion, bead formation in a rotating coating drum, etc. Bonding techniques by agglomerating composite particles having a diameter of no greater than about 0.1mm into particles having a diameter of at least about 1mm by a granulating fluid may also be used.

As is well known to those skilled in the art, the agglomeration may optionally be carried out in the presence of additional amorphous or crystalline binders, and a pore former may be added to the mixture to be agglomerated. Conventional binders include other forms of alumina, silica-alumina, clay, zirconia, silica-zirconia, magnesia, and silica-boria. Conventional pore formers which may be used include, in particular, wood flour, charcoal, cellulose, starch, naphthalene and all organic compounds which can generally be removed by calcination. The addition of a pore former is not necessary or desirable.

The agglomerate may then be aged, dried and/or calcined if desired.

Once formed, the agglomerates are typically then subjected to a heat activation treatment at a temperature of from about 250 to about 1000, preferably from about 350 to about 900, and most preferably from about 400 to about 800 ℃ for a period of time of from about 0.15 to about 3.0, preferably from about 0.33 to about 2.0, and most preferably from about 0.5 to about 1 hour. The activating atmosphere is typically air, but may include an inert gas such as nitrogen or water vapor.

If desired, the activation treatment may be performed in several steps or as part of the agglomeration treatment. Depending on the particular activation temperature and time used, the alumina agglomerates exhibit predominantly the crystal structure characteristic of boehmite, or gamma-alumina, or mixtures thereof.

More specifically, boehmite will be continuously converted to gamma-alumina at calcination temperatures and times in excess of about 300 ℃ and 1 hour. However, gamma-alumina will have the pore properties of the boehmite derived. Moreover, at the preferred calcination temperatures and times, substantially all of the crystalline boehmite is converted to gamma-alumina. Thus, the sum of the crystalline boehmite content (wt%) and the gamma-alumina content resulting from boehmite calcination discussed above generally exceeds the original boehmite content resulting from activated alumina rehydration. This statement applies equally to composite particles that are activated and used directly in the form of composite particles without agglomeration.

γ-Al₂O₃The (alumina) percentages were determined as follows:

(1)100％γ-Al₂O₃is defined as gamma-Al₂O₃Integrated intensity of (440) peak of standard (area under peak).

(2) The (101) peak intensity of the quartz plate was used as an X-ray intensity detection.

(3) Philips in a Cu X-ray tube equipped with a graphite diffraction beam monochromator and a seal^*3720 data collection was performed on an autodiffractometer. The X-ray generator was operated at 45kV and 40 mA.

(4) Obtaining (440) gamma-Al by curve fitting₂O₃Full width at half maximum (FWHM) and integrated intensity (area under peak). In case one peak does not yield a good fit of the diffraction peak, two peaks are used. In the case of curve fitting with two peaks, two crystal sizes were obtained by using equation 3. Percent of two crystal sizes gamma-Al₂O₃Obtained by using equation 2.

(5) gamma-Al of the sample₂O₃The percentage of (d) is determined by the following equation:

％_γ-Al2O3＝(I_{sample (I)}×I_{Quartz, c})/(I_{Standard sample}×I_{Quartz, s}) (equation 2)

Wherein:

I_{sample (I)}Integrated intensity of the (440) peak of the sample;

I_Quartzc ═ 101 intensity of quartz peak, measured on a standard gamma-Al₂O₃Measuring time;

I_{standard sample}gamma-Al as standard sample₂O₃Integrated intensity of the (440) peak of (c); and

I_Quartzand, s ═ 101, the intensity of the quartz peak, measured at the time of measuring the sample.

Gamma-Al was measured by the following procedure₂O₃Crystal size (L). The samples were ground manually with a mortar and pestle. A uniform layer of the sample was placed on 3.5 grams of polyvinyl alcohol (PVA) and then pressed at 3,000psi for 10 seconds to obtain a tablet. The tablets were then scanned with Cu ka radiation and diffraction patterns between 63-73 degrees (2 θ) were made. The peak at 66.8 degrees (2 θ) was used to calculate the crystal size using equation 3 and the measured half-peak width.

L (size in angstroms) ═ 82.98/FWHM (2 θ °) cos (θ °) (equation 3)

Wherein:

FWHM is the entire width at half maximum; and

θ is the diffraction angle between the X-ray beam and the sample fixation plane.

The percentage of boehmite was determined as described in example 1.

The large average pore size and high pore volume make the alumina composite of the present invention suitable for processing: treating high molecular weight, high boiling point feedstocks in f.c.c. and hydrotreating operations, wherein not all of the feedstock is actually capable of vaporization; short contact time cracking operations, where large pores can reduce diffusion resistance; hydrocracking, hydrotreating, hydrodesulfurization, and hydrodenitrogenation; processing tar sands, shale oil extract or coal slurry; a metal-containing catalyst support having a high void volume and void diameter that improves metal dispersion; separation of high molecular weight compounds from low molecular weight compounds in a solvent; and applications requiring fine particle size alumina at low pH, such as suspending agents and polishing agents.

The alumina composite particles are particularly suitable for use as supports for various catalyst systems using heavy metals as catalyst components. Therefore, the metal component of such a catalyst must be added and incorporated into the alumina composite. Thermal activation is typically performed after the formation of the agglomerates, rather than before.

Such addition may be achieved by mixing the catalytic material with the alumina by impregnating the alumina agglomerates, such as extrudates or tablets, with the catalytic material by dipping the alumina agglomerates in a solution containing the catalytic material or the like during the composite alumina production process but after rehydration thereof, during the preparation of the agglomerates, such as extrudates or tablets. A "dry" impregnation technique is another suitable candidate, in which the composite particles or agglomerates are contacted with an amount of impregnating solution, the volume of which corresponds to the pore volume of the support. Other and additional methods of modifying alumina may be desirable to those skilled in the art.

The porous composite aluminas of the present invention are particularly useful when used as supports for catalytically active hydrogenation components such as group VIB and group VIII metals. These catalytically active materials may suitably be used in hydroprocessing operations.

More specifically, the term "hydroprocessing" as used herein refers to a refinery process that reacts a petroleum feedstock (a complex mixture of hydrocarbons present in petroleum that are liquid under standard temperature and pressure conditions) with hydrogen at high pressure in the presence of a catalyst to reduce: (a) a concentration of at least one of sulfur, contaminant metals, nitrogen, and conradson carbon residue present in the feedstock, and (b) at least one of a viscosity, pour point, and density of the feedstock. Hydrotreating includes hydrocracking, isomerization/dewaxing, hydrofinishing, and hydrotreating processes in which the amount of hydrogen reacted and the nature of the petroleum feedstock being treated differ.

Hydrofinishing is generally understood to refer to the treatment of hydrocarbon oils ("feedstocks") containing predominantly (by weight) hydrocarbon compounds in the lube oil boiling range in which the feedstock is contacted with a solid supported catalyst under conditions of elevated pressure and temperature in order to saturate aromatic and olefinic compounds and remove nitrogen, sulfur and oxygen compounds present in the feedstock and improve color, odor, thermal, oxidative, and ultraviolet stability and properties of the feedstock.

Hydrocracking is generally understood to involve the hydrotreatment of predominantly hydrocarbon compounds containing at least 5 carbon atoms per molecule ("feedstock"), which is carried out under the following conditions: (a) at superatmospheric hydrogen partial pressure; (b) typically less than 593.3 ℃ (1100 ° F); (c) hydrogen gas consumed with bulk purification; (d) in the presence of a solid supported catalyst comprising at least one hydrogenation component; and (e) wherein the feedstock typically produces greater than about 130 moles of hydrocarbons containing at least 3 carbon atoms per molecule for every 100 moles of feedstock containing at least 5 carbon atoms per molecule.

Hydrotreating is generally understood to involve hydrotreating of hydrocarbon compounds containing mainly at least 5 carbon atoms per molecule ("feedstock") for the desulfurization and/or denitrification of the feedstock, wherein the process is carried out under the following conditions: (a) at superatmospheric hydrogen partial pressure; (b) typically less than 593.3 ℃ (1100 ° F); (c) hydrogen gas in total chemical consumption; (d) in the presence of a solid supported catalyst comprising at least one hydrogenation component; and (e) wherein: (i) said feedstock gives a yield of hydrocarbons containing at least 3 carbon atoms per molecule, generally ranging from about 100 to about 130 moles (both endpoints inclusive), per 100 moles of starting feedstock; or (ii) the feedstock contains at least 50 liquid volume percent of an undeasphalted residue that typically boils above about 565.6 ℃ (1050 ° F) as determined by ASTM D-1160D distillation and the primary function of hydrotreating is to desulfurize the feedstock; or (iii) the feedstock is a product of a synthetic oil production operation.

Isomerization/dewaxing is generally understood to involve the predominantly hydroprocessing of hydrocarbon oils having a Viscosity Index (VI) and a boiling range suitable for use in lubricating oils ("feedstocks") in which the feedstock is contacted under conditions of elevated pressure and temperature and in the presence of hydrogen with a solid catalyst containing a microporous crystalline molecular sieve as the active ingredient to produce a product having significantly improved cold flow properties relative to the feedstock and a boiling range substantially within the boiling range of the feedstock.

More specifically, well-known hydroprocessing catalyst components generally comprise at least one heavy metal component selected from the group consisting of group VIII metals, including group VIII platinum metals, especially platinum and palladium, group VIII iron metals, especially cobalt and nickel, group VIB metals, especially molybdenum and tungsten, and mixtures thereof. Group VIII platinum group metals can be used as the hydrogenation component if the feedstock has a sufficiently low sulfur content, for example less than about 1 wt.%, and preferably less than about 0.5 wt.%. In this embodiment, the group VIII platinum group metal is preferably present in an amount of from about 0.01 wt.% to about 5 wt.% of the total catalyst, calculated as the elemental platinum group metal. When the feedstock being treated contains greater than about 1.0 wt.% sulfur, the hydrogenation component is preferably a combination of at least one group VIII iron group metal and at least one group VIB metal. The non-noble metal hydrogenation component preferably present in the final catalyst composition is present in the form of an oxide or sulphide, more preferably a sulphide. Preferred overall catalyst compositions contain at least about 2, preferably from about 5 to about 40, weight percent of a group VIB metal, more preferably molybdenum and/or tungsten, usually at least about 0.5, preferably from about 1 to about 15, weight percent of a group VIII metal of the periodic Table of the elements, more preferably nickel and/or cobalt, measured as the corresponding oxide. The sulfide forms of these metals are more preferred because of their higher activity, selectivity, and activity retention properties.

Catalyst components, such as hydrotreating catalyst components, can be introduced into the overall catalyst composition by any of a number of methods described.

Although the non-noble metal component may be incorporated into the catalyst in sulphide form, this is not preferred. Such components are typically combined in the form of metal salts that can be converted to the corresponding oxides by heating in an oxidizing atmosphere, or reduced with hydrogen or other reducing agents. The composition is then sulfurized by reaction with a sulfur compound such as carbon disulfide, hydrogen sulfide, hydrocarbon mercaptans, elemental sulfur, and the like.

The catalyst components may be incorporated into the composite alumina at any one of a number of stages in the catalyst preparation process. For example, after rehydration, metal compounds such as sulfides, oxides or water soluble salts such as ammonium heptamolybdate, ammonium tungstate, nickel nitrate, cobalt sulfate, etc. may be added by co-milling, impregnation or precipitation methods prior to final coalescence of the composite. Alternatively, these components may be added to the composite after coalescence by impregnation with a water, alcohol or hydrocarbon solution of the soluble compound or precursor.

Another embodiment of the invention is directed to a process for hydroprocessing a hydrocarbon feedstock in at least one ebullated-bed reaction zone. More specifically, the hydrocarbon feedstock is contacted with hydrogen in one or a series of ebullated bed reaction zones in the presence of a hydrotreating catalyst comprising a hydrogenation component of catalytic metals and derivatives as described above deposited on an alumina composite agglomerate as described herein.

It is well known that these contain nickel, vanadium, and asphaltenes, for example, in amounts of from about 40ppm to greater than 1,000ppm of the total nickel and vanadium, and up to about 25 wt% asphaltenes. In addition, the economics of these processes favor the production of lighter products as well as the residual by-product of demetallization. This process is particularly useful for treating feedstocks containing significant amounts of metals, i.e., containing 150ppm or more nickel and vanadium and having a sulfur content of from about 1% to about 10% by weight. A typical feedstock that can be satisfactorily treated by the process of the present invention contains a significant amount (e.g., about 90%) of components boiling slightly above 537.8 ℃ (1,000 ° F). Examples of typical feedstocks are crude oil, topped crude oil, petroleum hydrocarbon residues including atmospheric and vacuum residues, tar from tar sands and residues from tar sands oils, and hydrocarbon streams from coal. Such hydrocarbon streams contain organometallic contaminants that can have a deleterious effect in the conversion of the particular hydrocarbon stream being treated in the various refinery processes in which the catalyst is used. Metal contaminants found in such feedstocks include, but are not limited to, iron, vanadium, and nickel.

While metal contaminants such as vanadium, nickel, and iron are often present in various hydrocarbon streams, other metals are also present in certain hydrocarbon streams. Such metals are present as oxides or sulfides of the particular metal, or as soluble salts of the particular metal, or as high molecular weight organometallic compounds, including metal naphthenates and metal porphyrinates and derivatives thereof.

Another characteristic phenomenon of hydroprocessing heavy hydrocarbons is the precipitation of insoluble carbonaceous material from the asphaltene fraction of the feedstock, which leads to operability problems. The amount of such insoluble material formed increases with the amount of material converted having a boiling point above 537.8 ℃ (1,000 ° F) or with the increase in reaction temperature used. These insoluble materials, also known as shell hot filtration solids, create operational difficulties for the hydroconversion unit, thereby limiting the temperatures and feedstocks at which the unit can operate. In other words, the amount of solids formed limits the conversion of a given feedstock. The operability difficulties described above can begin to arise with solids contents as low as 0.1 wt.%. Levels below 0.5 wt.% are generally recommended to prevent fouling of process equipment. A description of the Shell thermal filtration test can be found in the Journal of the inst.of Petroleum (1951)37, page 596-.

It has been speculated that such insoluble carbonaceous materials are formed when converting heavy hydrocarbons in a hydroconversion unit, making them poor solvents for unconverted asphaltene fractions, thus producing insoluble carbonaceous materials. The formation of such insolubles can be reduced by having a portion of the surface area in the hydroconversion catalyst occupied by very large pores, such that a large portion of the catalyst surface can accommodate large asphaltene molecules. Also, the large pores promote the deposition of nickel and vanadium in the hydroprocessing catalyst without clogging the pores.

It has been found that the use of the porous composite as a support for the manufacture of catalysts, particularly hydroprocessing catalysts, provides a higher initial activity than catalysts supported on conventional alumina.

While the benefits of higher initial activity are not significant in fixed bed operations, it is particularly important in ebullated bed systems. More specifically, in ebullated bed systems, the increase in initial activity is significant because of the need to add catalyst intermittently or continuously to increase and maintain overall system activity. Since the overall activity of the ebullated-bed system is the weighted average activity of all catalysts present, including fresh to deactivated catalyst, the overall activity can be increased by adding catalyst with higher original activity continuously or intermittently.

Hydroprocessing operations are typically carried out in one or a series of ebullated bed reactors. As previously mentioned, an ebullated bed is a reactor in which solid catalyst particles are kept in random motion by upward liquid and gas flows. The ebullated bed typically has a total volume at least 10% greater and up to 70% greater than the volume of its settled state of solids. The desired boiling of the catalyst particles is maintained by introducing the liquid feedstock, including recycle if present, to the reaction zone at a linear velocity of from about 0.02 to 0.4 ft/sec, preferably from about 0.05 to 0.20 ft/sec.

Operating conditions for hydroprocessing heavy hydrocarbon streams such as petroleum hydrocarbon residue oils and the like are well known in the art and include a pressure of from about 1,000psia (68 atmospheres) to about 3,000psia (204 atmospheres), an average catalyst bed temperature of from about 700 ° F (371 ℃) to about 850 ° F (454 ℃), a Liquid Hourly Space Velocity (LHSV) of from about 0.1 volumes of hydrocarbon/hour/volume of catalyst to about 5 volumes of hydrocarbon/hour/volume of catalyst, and about 2,000 standard cubic feet per barrel (SCFB) (356 m)³/m³) -about 15,000SCFB (2,671 m)³/m³) The hydrogen recirculation rate or the hydrogen addition rate. Preferably, the operating conditions include a total pressure of from about 1,200psia to about 2,000psia (81 to 136 atmospheres); an average catalyst bed temperature of about 730 ° F (387 ℃) to about 820 ° F (437 ℃); and an LHSV of about 0.1 to about 4.0; and about 5,000SCFB (890 m)³/m³) -about 10,000SCFB (1,781 m)³/m³) The hydrogen recirculation rate or the hydrogen addition rate. In general, the process temperature and space velocity are selected so that at least 30 volume percent of the feed fraction boiling above 1,000 ° F is converted to a product boiling below 1,000 ° FMore preferably such that at least 70% by volume of said fraction is converted to product boiling below 1,000 ° F.

For the processing of hydrocarbon distillation products, the operating conditions typically include a hydrogen partial pressure of from about 200psia (13 atmospheres) to about 3,000psia (204 atmospheres); an average catalyst bed temperature of from about 600 ° F (315 ℃) to about 800 ° F (426 ℃); an LHSV of from about 0.4 volumes of hydrocarbon per hour per volume of catalyst to about 6 volumes of hydrocarbon per hour per volume of catalyst; about 1,000SCFB (178 m)³/m³) -about 10,000SCFB (1,381 m)³/m³) The hydrogen recirculation rate or the hydrogen addition rate. Preferred operating conditions for hydrotreating the hydrocarbon distillation product include a hydrogen partial pressure of from about 200psia (13 atmospheres) to about 1,200psia (81 atmospheres); an average catalyst bed temperature of from about 600 ° F (315 ℃) to about 750 ° F (398 ℃); an LHSV of from about 0.5 volumes of hydrocarbon per hour per volume of catalyst to about 4 volumes of hydrocarbon per hour per volume of catalyst; about 1,000SCFB (178 m)³/m³) About 6,000SCFB (1,068 m)³/m³) The hydrogen recirculation rate or the hydrogen addition rate.

However, the most desirable conditions for the conversion of a particular feedstock to a predetermined product can be achieved by converting the feedstock at several different temperatures, pressures, space velocities, and hydrogen addition rates, correlating the effects of each of these variables, and selecting the best compromise in overall conversion and selectivity.

All references herein to elements or metals belonging to a certain group refer to the periodic Table of the elements and to Hawley's Condensed Chemical Dictionary, 12 th edition. Similarly, all references to a group refer to the group reflected in this periodic Table of the elements of the CAS system using the numbered group.

All statements in the claims regarding topographical properties as defined by weight, such as surface area, and pore volume, are to be interpreted as metal-free basis as defined in equation 6, e.g., normalized to correct for any effect of the metal catalytic oxide (if present) on the weight of the material being analyzed. Unless otherwise indicated, all of the composites in powder form (non-agglomerated) in the examples were filtered after rehydration and then exchanged to a low sodium form by a/S exchange as described above prior to calcination. None of the extruded samples were A/S exchanged.

The following examples are given as specific illustrations of the invention. It should be understood, however, that the invention is not limited to the specific details set forth in the examples. All parts and percentages in the examples, as well as in the remainder of the specification, are by weight unless otherwise indicated. Unless otherwise indicated herein, all surface area and pore performance tests or statements in this specification and claims will be limited to those performed on samples that have been oven dried at 138 ℃ (280 ° F) and then calcined in air at 537.8 ℃ (1000 ° F) for 2 hours at atmospheric pressure.

In addition, any numerical range recited in the specification or claims, such as that representing a particular property, condition, physical state or percentage, is intended to literally incorporate expressly herein any number falling within such range, including any subset of numbers within any range so recited.

Example 1

1843 g of H₂To O was added 14.4 grams of a dry-based Laponite * RD, a synthetic hectorite clay available from LaPorte Industries, Ltd. The resulting mixture was rapidly stirred for 20 minutes to disperse the clay. A slightly cloudy solution formed, almost as transparent as water, indicating very good finely divided clay. To Laponite * dispersion was added 23.5 grams of 10% aqueous sodium gluconate solution followed by 465.6 calcined activated alumina to obtain CP-3 from ALCOA. The slurry was boiled under reflux conditions for 24 hours. The slurry was filtered and dried at 137.8 deg.C (280 deg.F) overnight. The resulting composite particles were then dry calcined at 537.8 ℃ for 2 hours (referred to herein as fresh), or at 800 ℃ in 20 volume% steam for 4 hours (referred to herein as steamed) and the surface areas of the fresh and steamed samples were measured.

The percent conversion of the alumina sample to crystalline boehmite was determined as follows:

(1) 100% boehmite was defined as the integrated intensity of the (020) peak (area under the peak) of Catapal alumina.

(2) The (101) peak intensity of the quartz plate was used as an X-ray intensity detection.

(3) Data collection was performed on a Philips * 3720 autodiffractometer equipped with a graphite diffraction beam monochromator and a sealed Cu X-ray tube. The X-ray generator was operated at 45kV and 40 mA.

(4) The full width at half maximum (FWHM) and integrated intensity (area under the peak) of the (020) boehmite peak were obtained by curve fitting. In case one peak does not yield a good fit of the diffraction peak, two peaks are used. In the case of curve fitting with two peaks, two crystal sizes were obtained by using equation 5. The boehmite percentages for the two crystal sizes were obtained by using equation 4.

(5) The percentage of boehmite of the sample was determined by the following equation:

％_{boehmite (BO)}＝(I_{Sample (I)}×I_{Quartz, c})/(I_catapal×I_{Quartz, s}) (equation 4)

Wherein:

I_{sample (I)}Integrated intensity of the (020) peak of the sample;

I_{quartz, c}(101) intensity of quartz peak, measured when Catapal alumina is measured;

I_catapalintegrated intensity of the (020) peak of Catapal aluminum hydride;

I_{quartz, s}Intensity of quartz peak (101), measured at the time of measuring the sample.

The boehmite crystal size (L) was determined by the following procedure. The samples were ground manually with a mortar and pestle. A uniform layer of the sample was placed on 3.5 grams of polyvinyl alcohol (PVA) and then pressed at 3,000psi for 10 seconds to obtain a tablet. The tablets were then scanned with Cu ka radiation and diffraction patterns between 22-33 degrees (2 θ) were made. The peak at 28 degrees (2 θ) was used to calculate the crystal size using equation 5 and the measured half-peak width.

L (size in angstroms) ═ 82.98/FWHM (2 θ °) cos (θ °) (equation 5)

Wherein:

FWHM is the entire width at half maximum; and

θ is the diffraction angle between the X-ray beam and the sample fixation plane.

The properties resulting from the analysis are reported in table 2 and fig. 1 and are referred to as test 2. The addition of 3% Laponite * resulted in increased fresh and steamed surface area compared to comparative example 1. Figure 1 also shows a large increase in total nitrogen pore volume and a shift towards larger pores.

Comparative example 1

Example 1 was repeated, but no Laponite * was added to the samples. The results are reported in table 2, fig. 1 and referred to as test 1.

TABLE 2

Adding LAPONITE 3%^*Obtained by rehydrating activated alumina

Effect of boehmite surface Properties

Test number	1	2
				Comparative example 1	Example 1
Laponite*In percentage by weight	0	3
			Boehmite properties after 24 hours of thermal aging at 100 ℃ (212 ° F)
Average pore diameter (*)	149	197
			Total pore volume (cc/g)	0.668	1.378
Pore volume > 600 * (cc/g)	0.046	0.298
			Mesopore volume (cc/g)	0.205	0.774
Mesopore content (% TPV)	30.6	56.2
			Large pore specific surface area (m)2/g)	2.8	17.2
Ultimate value of mesopore porosity (*)	70	200
			Increase in mesopore size by the greatest factor%	N/A	185
Surface area
			537.8 ℃ for 2 h (fresh) (m)2/g)	179	279
Micropore surface area (fresh) (m)2/g)	0	0
			Mesopore surface area (fresh) (m)2/g)	179	279
Conversion of activated alumina to boehmite%	83	78
			20% steam aged surface area (m) at 800 ℃ for 4 hours2/g)	112	182

Example 2

Example 1 was repeated, however, with the synthetic hectorite Laponite^*The amount of (A) varies from 0.1 to 10% by weight of the total solids (Laponite)^*+ alumina) (corresponding to runs 3-12). In returnAfter aging under flow for 24 hours, the sample was filtered and dried at 137.8 ℃ (280 ° F) overnight. Selected samples were tested for boehmite crystal size and surface area after calcination at 537.8 ℃ (1000 ° F) for 2 hours, or in 20% steam at 800 ℃ for 4 hours. The dispersibility index (DPI) of the composite particles was also measured. This test determines the percentage of particles having a particle size of less than 1 micron after being dispersed in water with a measured amount of HCl (237 milliequivalents/mole of alumina) and mixed. The results of the effect of the amount of synthetic hectorite on the boehmite properties are summarized in table 3. It can be observed that dispersible swelling clays:

(a) increasing the total nitrogen pore volume and the average pore diameter to a maximum value in the range of 3-5 wt%;

(b) reducing boehmite crystal size;

(c) significantly increased fresh and evaporated surface area and nitrogen-method pore volume;

(d) when 3% by weight or more of clay is added, dispersibility of alumina is increased.

It should also be noted that as the weight percentage of the added synthetic clay increases, the hardness of the oven dried boehmite increases. At 0% by weight, the oven dried material is a soft powder, at 3% by weight clay it is medium hard, and at 5-10% by weight it is quite hard. This is believed to indicate that extrudates/beads from composite particles containing 3 wt% or more clay have high crushing strength. The curve of the nitrogen method pore size distribution at clay contents of 0-1 wt.% is shown in fig. 2 and the curve at clay contents of 0-6 wt.% is shown in fig. 3.

FIG. 2 shows the effect of milled/unmilled 3% LAPONITE on the 800 ℃ steamed surface area of boehmite from rehydrated calcined alumina, which is actually shown at low levels of LAPONITE^*In the following, the mesopore porosity decreases by the greatest amount. FIG. 3 shows a consistent shift towards higher mode mesopores at higher clay concentrations of 2-5 wt.%. Table 3 shows the peak value of the Total Pore Volume (TPV), the Average Pore Diameter (APD), and the fresh value at a clay concentration of 5 wt%And the peak evaporated Surface Area (SA).

TABLE 3

LAPONITE^*Effect of content on fresh and distilled boehmite Properties

Test number	3	4	5	6	7	8	9	10	11	12
											Laponite*By weight%	0	0.5	1	2	3	4	5	6	8	10
Conversion of activated alumina to boehmite%	83	NA	72	72	78	79	65	NA	68	NA
											Crystal size, (*)	128	114	99	81	94	79	62	63	74	69
DPI(％)	21		20	27	99	100	100	100	100	100
											537.8 deg.C, 2 hours
BET surface area (m)2/g)	179	263	289	317	279	311	315	290	295	286
											Micro pore surface area (m)2/g)	0	0	0	0	0	0	0	0	0	0
Mesopore surface area (m)2/g)	179	263	289	317	279	311	315	290	295	286
											Average pore diameter (*)	149	90	95	122	197	153	188	112	89	88
Total pore volume (cc/g)	0.668	0.592	0.687	0.966	1.378	1.184	1.479	0.813	0.659	0.629
											Surface area based on distribution (m)2/g)	276	456	450	436	341	373	388	354	340	335
Pore volume > 600 * (cc/g)	0.046	0.054	0.055	0.226	0.298	0.222	0.176	0.061	0.035	0.034
											Mesopore content (%)	34	16	22	31	55	68	67	47	42	37
Macropore content (%)	8.6	10	9	21	26	26	15	8	6	6
											Ultimate value of mesopore porosity (*)	70	39	39	140	206	200	180	103	120	125
The pores are increased by the greatest amount%	N/A	-45	-45	100	194	186	154	47	71	79
											Calcination at 800 ℃ for 4 hours (20% steam)
BET surface area (m)2/g)	112	131	150	184	182	198	228	209	213	203
											Micro pore surface area (m)2/g)	0
Mesopore surface area (m)2/g)	112
											Average pore diameter (*)	230
Total pore volume (cc/g)	0.643
											Surface area based distribution (m)2/g)	142.5
Pore volume > 600 * (cc/g)	0.07
											Retention of surface area%	62.6	49.8	51.9	58	65.2	63.7	72.4	72.1	72.2	71
											Note that: total pore volume by nitrogen method measured at a relative pressure of 0.995P/Po. Surface area calculated from the nitrogen-based pore size distribution of pores having a pore diameter of 20 to 600 *%

Example 3

This example illustrates the drying conditions and the effect of Total Volatiles (TV) on the dispersion properties of synthetic hectorite, measured at 954.4 ℃ (1750 ° F), and thus on the alumina product.

A 2 gallon autoclave batch of synthetic hectorite was prepared according to example 2 of us patent 4,049,780.

After high pressure treatment, the synthetic hectorite gel slurry was filtered, washed with water and divided into samples 1-4 as follows:

(1) remaining in the form of a filter cake, TV 83.43%

(2) Oven-dried at 100 deg.C (212 deg.F) overnight, 12.83% TV

(3) Spray Drying (SD) at 130 deg.C outlet temperature, 19.38% TV%

(4) Spray-drying at 180 deg.C outlet temperature, TV 15.45%

Spray dried samples 3 and 4 were prepared by repulping the filter cake to approximately 2% solids content and then spray dried in a small bench top spray dryer.

Four alumina/synthetic hectorite composites were prepared according to example 2, but using 3 wt.% of one of the synthetic hectorite samples 1-4. The solids content of each clay/alumina slurry was 17 wt%. More specifically, each of the above synthetic hectorite samples 1-4 was rapidly stirred in water for 1/2 hours to make a slurry. Calcined alumina was then added to each slurry and boiled under reflux with good stirring for 24 hours. The effect of synthetic hectorite on alumina pore volume is shown in Table 4, runs 13-16. The total pore volume of the boehmite product increases with increasing dispersion properties of the synthetic hectorite. It can be intuitively noted that the transparency (and dispersion property) of water in which synthetic hectorite is dispersed increases in the following order: filter cake < oven dry < s.d. at 130 < s.d. at 180 ℃, which is a sequence of increasing pore volume, average pore diameter and dispersion index of alumina. Thus, the drift in pore volume can be controlled by the content of dispersible swelling clay used and/or the degree of dispersion of the swelling clay. The degree of dispersion or size of the clay particles in the dispersion can be controlled by the clay synthesis conditions (molar feed ratio, autoclave temperature, etc.) or drying conditions. It should also be noted that the fresh and steamed surface area of sample 4 is still higher than sample 1 and a much higher TPV is obtained.

TABLE 4

Synthetic hectorite drying conditions for a polymer obtained from a 3% clay-containing polymer

Effect of activated alumina on boehmite surface Properties

Test number	13	14	15	16
					Synthetic hectorite sample number	1	2	3	4
Drying type	Do not dry (filter cake)	Oven drying (212 degree F overnight)	Spray drying at 130 deg.C	Spray drying at 180 deg.C
					Clay TV	83.43％	12.83％	19.38％	15.45％
The weight of the clay added	3％	3％	3％	3％
					Alumina quality [537.8 deg.C (1000 deg.F.) calcination for 2 hours]
BET surface area (m)2/g)	261	295	2285	264
					Average pore diameter (*)	119	172	195	216
General holeVoid volume (cc/g)	0.773	1.268	1.387	1.428
					Dispersibility index (%)	20	36	62	94
Hydrothermal stability
					Surface area (m) at 800 ℃ in 20% by volume of steam for 4 hours2/g)	195	238	230	213

Example 4

This example illustrates the effect of dispersancy on the topographical properties of composites adjusted by the clay-forming reaction temperature

Generally according to example 3, by feeding 1,169 g of H₂To O was added 97.9 g of silicic acid (H)₄SiO₄) 58.3 g Mg (OH)₂2.55 g LiCl, and 4.7 g NaCl and boiled under reflux for 24 hours at 1.49 mol SiO₂A first synthetic hectorite sample, designated SH-1, was prepared with a feed rate of 1.0 moles of MgO, 0.06 moles of Li, 0.08 moles of Na, designated run 16-1. Using 1,083 g of H₂To O was added 87.4 g of silicic acid, 58.3 g of Mg (OH)₂And 10.5 grams LiClAnd thermally aged in a plastic bottle at 101.7 c (215F) for 24 hours to prepare a second synthetic hectorite sample (SH-2), designated test 16-2. Both samples had the X-ray diffraction pattern of hectorite. A slurry of each clay was prepared by mixing in water for 2 minutes and 291 grams CP-3 calcined alumina on a dry basis and 1.5 grams sodium gluconate were added to the slurry. The weight ratio of synthetic clay/alumina was 3/97. The slurry was boiled under reflux for 24 hours, filtered and dried. It was observed that for SH-1 and SH-2, during the reflux of the synthetic hectorite feedstock, the particles coarsened and could not be dispersed into a colloidal sol.

The nitrogen method pore size distribution results are summarized in figure 4 together with the comparative curve of trial 3. These results show that the alumina prepared with synthetic hectorites (SH-1 and SH-2) that are non-dispersible or poorly dispersible does not have the same shift in nitrogen process pore size distribution as the comparative sample without any synthetic hectorite. The amounts of reactants SH-1 and SH-2 are summarized in Table 5.

TABLE 5

Test number	16-1	16-2
			Reactants	Sample number SH-1 (gram)	Sample number SH-2 (gram)
H4SiO4	97.9	87.4
			Mg(OH)2	58.3	58.3
LiCl	2.55	10.5
			NaCl	4.7	0
H2O	1,169	1,083

Generally, the higher the temperature or longer the time the synthetic hectorite is reacted, the higher its dispersibility. Thus, reaction formation temperatures of at least 150 ℃ and 200 ℃ are preferred. Such temperatures can be obtained with an autoclave.

Example 5

This example illustrates the effect of using high purity non-fluorinated hectorite in place of synthetic hectorite. Two high purity natural hectorite samples were obtained from American Colloid Co. These clays, Hectalite 200 (individually referred to as NH-1) and Hectawrite DP (referred to as NH-2), were dispersed in a mixer for 1 minute. Calcined alumina and sodium gluconate were then added to each dispersion to give 3% clay and 97% calcined alumina (CP-3, ALCOA). The gluconate content was 0.5 wt.% calculated on alumina. The two slurries were stirred under reflux and boiled for 24 hours, filtered and dried. The nitrogen method pore size distribution results are reported in figure 5. The process was repeated using clay samples SH-1 and SH-2 and referred to as runs 20 and 21.

A sample of comparative alumina designated CE-2 was also prepared according to example 5, but without the addition of clay.

Comparison of the curves of FIGS. 1 and 3 with the curves of FIG. 5 shows that the mesopores shift only slightly towards larger diameters when using natural hectorites, relative to synthetic hectorites (runs 20-21). The natural hectorite samples (runs 18-19), the sample from run 7 and the comparative sample CE-2 (run 17) are also reported in Table 6.

TABLE 6

Effect of various hectorites on the pore structure of boehmite

Test number	17	18	19	20	21	7
							Sample numbering	CE-2	NH-1	NH-2	SH-1	SH-2	TABLE 3 run 7
Clay clay	0	Hectorite (hectorite)	Hectorite B	Synthetic hectorite	Synthetic hectorite	LAPONITE*
							The weight of the additive	0	4	4	3	3	3
BET surface area (m)2/g)	179	235	221	257	263	279
							Micro pore surface area (m)2/g)	0	0	0	0	0	0
Mesopore surface area (m)2/g)	179	235	221	257	263	279
							Average pore diameter (*)	149	166	127	106	102	197
Total pore volume (cc/g)	0.668	0.979	0.702	0.681	0.674	1.378
							Surface area based distribution (m)2/g)	275.9	319.6	276.8	429.9	441.2	341
Pore volume > 600 * (cc/g)	0.046	0.143	0.039	0.061	0.049	0.298

Example 6

This example illustrates the effect of synthetic hectorite on the hydrothermal stability of various calcined aluminas. Thus, using the procedure of example 1, a calcined alumina available from Porocel under the trade name AP-15 was used to prepare the boehmite/Laponite * composite, but the amount of dispersible hectorite (Laponite. rtm. rd) varied between 0, 1.5 and 3 wt% and no sodium gluconate was used (run 22). The results show that good hydrothermal stability is obtained with or without addition of gluconate. The stability is very similar to that obtained with CP-3 alumina.

The samples obtained are aged in water vapor (20%) at 800 ℃ for 4 hours and measured in m²The BET surface area is expressed as/g. In addition, composite samples were prepared according to example 1 using CP-3 alumina, but Laponite^*The contents vary by 0, 0.1, 0.2, 0.25, 1.5, 2,3 and 5% by weight and the resulting product is aged as described above for the sample obtained for AP-15. The results are shown in FIG. 6 as test 23.

Example 7

This example illustrates the modification of synthetic Laponite before and after rehydration of calcined alumina^*The influence of the addition point of (c).

The boehmite batches from the calcined alumina were prepared as follows: to 1888 grams of H in a 3 liter glass container₂To O was added 24.4 grams of a 10 wt% sodium gluconate solution followed by 480 grams of calcined CP-3 alumina from ALCOA on a dry basis. The slurry was boiled under reflux conditions for 24 hours to rehydrate the alumina. The rehydrated alumina was then divided into 5 equal portions. Various amounts of Laponite were added to each portion^*Rd (laporte), said different amounts being 0, 2,4, 6 and 8 wt.%. The surface area of these materials was measured after aging in 20% water vapor at 800 ℃ for 4 hours and the results are reported as test 24 in fig. 7. The above procedure was repeated, but Laponite was added in amounts of 0, 0.25, 1.0, 2.0, 2.25, 3.0, 3.75, 4.0, 5.0, 6.0, 8.0 and 10 wt.% before refluxing the alumina, i.e. before rehydration^*. The resulting product was then aged in water vapor (20%) at 800 ℃ for 4 hours, the BET surface area was measured, and the results are summarized in test 25 in fig. 7. It can be seen that the addition of dispersible hectorite prior to rehydration (run 25) resulted in a product with higher hydrothermal stability relative to the addition after rehydration. It is believed that this is due to the higher fresh surface area, greater pore volume and mean pore diameter of this product when added at the beginning of rehydration, and better clay dispersibility in alumina.

Example 8

This example shows the effect of pre-milling a slurry containing a dispersible synthetic hectorite and calcined alumina (CP-3, ALCOA) on hydrothermal stability.

8,331 g of H were added under rapid stirring₂O with 51.9 g of Laponite^*RD (Laporte, TV ═ 13.26%). The slurry was aged with stirring at room temperature for 20 minutes to disperse the clay. The resulting substantially transparent solution demonstrates good colloidal dispersion of the clay. Adding to the dispersion under good stirring1,616.7 g of CP-3(TV 10%). Contains 3 wt.% of Laponite^*This slurry was then milled in a 4 liter DRAIS mill under vigorous (80% media, 0.75 liters/min) conditions. The milled slurry was boiled under reflux for 24 hours and a portion was filtered and dried. The resulting sample is referred to as run 28. The specification of 0.75 liter/min means that the feed/discharge to and from the mill is 0.75 liter per minute.

The above process was repeated, but the pre-milling was omitted. This sample is referred to as run 27.

Furthermore, a method in which Laponite is omitted was prepared^*And no pre-milled control sample was used. This sample is referred to as run 26.

All three samples were then divided into two portions, the first portion aged in 20% steam at 800 ℃ for 4 hours and the second portion aged at 537.8 ℃ for 2 hours. The surface area was then measured for each aged sample. The hydrothermal stability results are summarized in table 7. And the nitrogen method pore properties are shown in figure 8.

Table 7 shows that pre-grinding results in a product with significantly higher fresh surface area and surface area after steaming than without the clay base or compared to the sample with the same amount of clay without grinding. Nitrogen method pore size distribution results show that pre-grinding produces a small shift toward more smaller diameter pores, but produces a higher TPV.

TABLE 7

	0％Laponite*	Unground 3% Laponite*	3% Laponi ground before agingte*
				Test number	26	27	28
	SA(m2/g)	SA(m2/g)	SA(m2/g)
				Surface area of 800 ℃ for 4 hours	115-119	195-210	281
537.8 deg.C, 2 hours	199	279	345
				Average pore diameter (*)	153	197	169
Total pore volume (cc/g)	0.761	1.378	1.461
				Ultimate value of mesopore porosity (*)	69	111	108
The mesopore size is at most increased%	N/A	61	56

Example 9

This example illustrates the effect and extent of pre-dispersion obtained with a laboratory preparation of synthetic hectorite dried to low TV (9.64%).

By adding 183.5 g of MgSO₄·7H₂A solution of O +3.4 g LiCl was added dissolved in 289 g H₂75.3 g Na in O₂CO₃The solution of (a) to prepare a synthetic hectorite. Then, 826 g of H are used₂267.4 g of silicate solution diluted with O (27.11% SiO)₂) Added during half an hour. The resulting gel slurry was boiled for 30 minutes to remove carbonate, then autoclaved at 200 ℃ for 2 hours, filtered, washed on the filter with 1 liter of 65.6 ℃ (150 ° F) deionized water and dried at 135 ℃.

The fractions were repulped in water as follows:

test 29: gently stir for 30 minutes

Test 30: disperse with a Silverson mixer at 10,000rpm for 10 minutes

Test 31: stir with a magnetic stir bar for about 18 hours.

Sufficient calcined alumina (CP-3, ALCOA) was added to each of the above slurries to produce a 15% solids slurry containing 3 wt.% synthetic hectorite and 97% alumina. The slurry was boiled under reflux with stirring for 24 hours. The slurry was filtered and dried at 137.8 deg.C (280 deg.F). The average pore diameter of each product from runs 29-31 was measured after calcination at 537.8 ℃ (1000 ° F) for 2 hours. Surface area and TPV were determined and the results are summarized in table 8.

For runs 29-31, the average pore diameters increased from 147 to 159 to 176 angstroms, respectively, indicating that better dispersion was obtained with increasing dispersion time and/or severity. It is believed that the sample was difficult to disperse due to its lower total volatile of 9.64%. Thus, the dispersibility of the clay can be improved by controlling TV, the degree of clay dispersion, or the clay crystal size, which in turn controls the average pore size of the alumina.

TABLE 8

Degree of dispersion of synthetic hectorite versus what is prepared by rehydration of activated alumina

Total N of boehmite₂Effect of Normal pore volume and average pore diameter

Test number	29	30	31
				Weight% of synthetic hectorite%	3	3	3
Clay dispersion	Slowly stirring30 minutes	The Silverson mixer (10,000rpm) was stirred for 10 minutes	Slowly stir for 18 hours
				Alumina Properties of 537.8 deg.C (1000 deg.F) calcination for 2 hours
Surface area (m)2/g)	286	284	284
				Pore diameter (*)	147	159	176
N2Farpeau volume (cc/g)	1.05	1.13	1.23

The total volatiles for the synthetic hectorite for the samples used in tests 29-31 was only 9.64%, which was considered difficult to disperse sufficiently regardless of the degree of agitation.

Comparative example 2

This example illustrates the effect of non-swellable clays such as kaolin or calcined kaolin on the pore structure.

Example 1 was repeated, but the clay used was kaolin or calcined kaolin, in the amounts indicated in table 9. The resulting composites were designated test 33 (kaolin), test 34(6 wt% calcined kaolin), and test 35(12 wt% calcined kaolin). The calcination of the kaolin was carried out at 900 ℃ for 0.66 hours. The surface properties of these materials were measured as fresh surface area and the results are reported in table 9. Comparative alumina without clay prepared by the same method was also used and is designated run 32. The amount of kaolin present in the composite particles is also reported in table 9. The nitrogen desorption data for runs 32-35 is also reported in figure 9. As can be seen from table 9 and fig. 9, the kaolin ultimately results in a decrease in average pore size (APD) and total pore volume, but an increase in surface area relative to the comparative sample. Kaolin is a non-swellable clay.

Example 10

This example illustrates the effect on pore properties of the less preferred montmorillonite Clay comparative example 2 was repeated, but the kaolin Clay was replaced by 6 wt% (run 36) and 12 wt% (run 37) of a montmorillonite Clay available from Southern Clay Products under the trade name Gelwhite L. A comparative sample of 0 wt% clay is referred to as run 32. The results are summarized in table 9 and fig. 10. It can be seen that the alumina pore nature and surface area at 6 wt% is greater than that of 12 wt% clay. Moreover, no rightward shift in the mesopore maximum values occurred, and the pore size distribution spread out. This is believed to be due to the difficulty of dispersing the montmorillonite without some other treatment such as significant grinding to reduce particle size, ion exchange, or the use of dispersants such as tetrasodium pyrophosphate.

Example 11

Comparative example 2 was repeated, but the kaolin was replaced by sodium silicate in an amount of 0.5% by weight (test 39) and 1% by weight (test 38). The comparison without silicate is run 32.

TABLE 9

Effect of various additives on the pore structure of boehmite

Test number	32	33	34	35	36	37	38
								Clay clay	Is free of	Kaolin clay	Calcined kaolin	Calcined kaolin	Guling rock	Guling rock	SiO from silicates2Of
By weight%	0	12	6	12	6	12	1
								Property of 537.8 deg.C (1000 deg.F) calcination for 2 hours
BET surface area (m)2/g)	199	186	298	311	246	239	281
								Average pore diameter (*)	153	129	91	77	138	116	102
N2Total pore volume by method (cc/g)	0.761	0.598	0.675	0.603	0.848	0.692	0.718
								Ultimate value of mesopore porosity (*)	69	58	39	39	70	70	40
Increase in mesopore size by the greatest factor%	N/A	-16	-44	-44	1	1	-42

The porosity properties were tested and the results are summarized in table 9 (for trial 38) and fig. 11. It can be seen that the silicate actually induces a sudden shift of the mesopore porosity, at best, to a smaller pore size. Thus, the silicate derived composite material may be mixed with the hectorite derived composite material in order to shift the pore structure as required for each intended use.

Example 12

This example illustrates the effect of grinding calcined alumina in the presence of swellable clay prior to rehydration on hydrothermal stability.

Thus, example 8 was repeatedTest 28, Laponite ground before rehydration^*(by 3 wt.%) and calcined alumina and is referred to as run 42. After refluxing at 100 deg.C (212 deg.F) for 24 hours, the boehmite was filtered and dried at 140 deg.C for 6 hours. The time was varied to calcine each portion of boehmite in an atmosphere of about 20% water vapor at 800 c and then the surface area was determined. The above procedure was repeated, however, the milling step was eliminated and the product was designated trial 41. Also prepared without Laponite^*And a comparative sample without the grinding step and designated test 40 and subjected to the same water vapor treatment and surface area determination. The results are summarized in fig. 12. Figure 13 represents the data points for each run of figure 12 in terms of the percentage of surface area obtained on a fresh sample calcined at 537.8 ℃ (1000 ° F) for 2 hours (i.e., heated in steam for 0 hour). This percentage is referred to as% surface area retention. It can be seen that the surface area stability increases in the following order: 0% Laponite.^*(test 40) < 3% Laponite^*(run 41) < 3% Laponite^*And grinding (run 42).

Example 13

This example illustrates the effect of post-synthesis addition of Na silicate to boehmite obtained from rehydrated calcined alumina.

Calcined alumina samples from ALCOA under the trade designation CP-3 (run 43) and calcined alumina samples from Porcel under the trade designation AP-15 (run 44) were each separately slurried at a solids content of 17 wt.% in water containing 0.5 wt.% (calculated as alumina) sodium gluconate and thermally aged under reflux for 24 hours. The two batches were then separated and the amount of sodium silicate added was varied, aged at 21 ℃ for about 30 minutes and aged with 4% H₂SO₄Adjusting the pH to 9.0, filtering, repulping with ammonium sulfate to remove Na₂And O, filtering, washing with water and drying. Each sample was steamed at 800 ℃ for 4 hours in about 20 vol% water vapor and the surface area was measured.

The results for each tested product are summarized in table 14. It can be seen that the silicate significantly improves the hydrothermal stability of the boehmite sample.

Example 14

This example illustrates the effect of adding silicate to the composite of the present invention after its formation.

3 wt.% (test 45) and 5 wt.% (test 46) of Laponite were used^*Rd (laporte) as a dispersible clay source to produce two batches of boehmite. Laponite was prepared by adding clay to water with rapid stirring and mixing for 20 minutes^*And (3) slurry. Sodium gluconate was added at 0.5 wt% (based on alumina) followed by a calcined alumina CP-3 from ALCOA. Each slurry was boiled under reflux for 24 hours with stirring, filtered and dried at 137.8 ℃ (280 ° F) overnight. The portions of each product were reslurried in water, sodium silicate was added and the mixture was aged at 21 ℃ for 30 minutes. With 4% H₂SO₄Adjusting pH to 9.0, filtering, and exchanging with ammonium sulfate in slurry form to remove Na₂O, filtered, washed with water and dried at 137.8 ℃ (280 ° F) overnight. Each sample was then contacted with 20 wt% water vapor at 800 ℃ for 4 hours. And the surface area was measured. SiO is provided in FIG. 15₂Weight% versus surface area after steaming. It can be seen that a very high surface area is obtained. Also, a comparison of these steamed surface areas to clay-free samples from example 13 (fig. 14) is provided in fig. 16. It can be seen that an increased surface area is obtained by combining the addition of a dispersible clay with the post-synthesis addition of silicate. It is believed that the higher surface area of the steamed alumina containing the dispersible clay is due in part to the higher fresh surface area, higher pore volume and higher average pore size.

Example 15

This example illustrates the effect of post-synthesis addition of silicate to alumina prepared with synthetic hectorite prepared only at 100 deg.C (212 deg.C) with poor dispersion (lower preparation temperature induces significantly lower dispersion).

By adding 1169 g of H to a 3-liter resin kettle with agitation₂In O97.9 g of silicic acid (H) are added₄SiO₄) A batch of synthetic hectorite was prepared. To the kettle were added, with stirring, 58.3 grams of Mg (OH), 2.55 grams of LiCl, and 4.7 grams of NaCl. The slurry was refluxed for 24 hours, filtered, washed 3 times with water at 65.6 ℃ (150 ° F), and dried at 137.8 ℃ (280 ° F). Obtained with Laponite^*RD very similar X-ray diffraction pattern. Enough of this dry material was added to 800ml of H₂Mixed in O for 2 minutes to obtain 3% of the final alumina weight and to disperse it as much as possible. And Laponite^*Compared to RD, an opaque slurry was obtained, indicating a low degree of dispersion. This slurry was mixed with 0.5 wt.% sodium gluconate (calculated as alumina) and additional H₂O was added together in a 3 liter resin kettle to obtain a slurry of 17% solids. CP-3 (calcined alumina from ALCOA) was then added. The slurry was boiled under reflux for 24 hours, filtered and dried at 137.8 deg.C (280 deg.F). Portions of the slurry were reslurried in water and various amounts of silicate were added as reported in test 49 of fig. 17. Each sample was steamed at 800 ℃ in about 20% steam for 4 hours and the surface area was measured.

The above procedure was repeated but with highly dispersed Laponite^*RD replaced the synthetic hectorite made and used for test 49. Each sample of the resulting product was tested for surface area and the result was referred to as run 48. These results are plotted in fig. 17.

A comparative sample was also made following the procedure of test 49, but no clay was used. The surface area is plotted in fig. 17 and referred to as run 47.

As can be seen from fig. 17, the surface area stability increases in the following order: no clay + silica < poorly dispersed clay + silica < well dispersed clay + silica.

Example 16

This example illustrates the effect of pre-milling a slurry containing calcined alumina and dispersible clay prior to rehydration and adding sodium silicate after synthesis.

In the rapid stirring stripUnder the condition of 8,331 g of H₂51.9 g of Laponite dispersed in O^*RD (13.26% TV) for 20 minutes, then 1,616.7 g CP-3 (calcined alumina from ALCOA, 10% TV) was added to make a slurry. The resulting slurry was milled in a 4 liter DRAIS mill with a glass media loading of about 60% at a flow rate of about 1 liter/minute. The slurry was boiled under reflux conditions for thermal aging for 24 hours, filtered and dried. This boehmite alumina sample was reslurried in water and contained varying amounts of sodium silicate as reported in Table 10, aged for 15 minutes at 21 deg.C, with 4% H₂SO₄The pH was adjusted to 9.0, filtered and designated as run 52. The above procedure was repeated but the milling step was omitted and the resulting sample was designated test 51. Comparative samples were also prepared, but the milling step and the addition of silica and clay were omitted. The comparative sample is referred to as run 50. Each of the samples of trials 50-52 was reslurried in water containing ammonium sulfate for 15 minutes, filtered, washed with water and dried. This exchange was performed to reduce Na₂To low levels (< 0.25 wt.%). The effect of calcining the samples at 800 ℃ in a 20 volume percent steam atmosphere for 4 hours on silicate content and the presence of a dispersible hectorite/ground on the surface area after steaming is then summarized in table 10. The highest surface area was obtained with or without the addition of silicate by milling.

Watch 10

Test number	50	51	52
					Alumina (Clay-free) (not ground) SA (m) from CP-32/gm)	Alumina from CP-3, no grinding (3% clay) SA (m)2/gm)	Milled alumina (3% clay) SA (m) before aging2/gm)
Surface area of 4 hours at 800 DEG C	115-119	195-210	281
				Containing 4% SiO2	179	250	302
Containing 8% SiO2	195	279	311
				537.8 deg.C (1000 deg.F), 2 hours
BET surface area	199	279	345
				Average pore diameter	153	197	169
Total pore volume	0.761	1.378	1.461
				Surface area retention (% by SiO)2Surface area meter)
0％SiO2	58.8	72.4	81.4
				4％SiO2	89.9	89.6	87.5
8％SiO2	98	100	90.1

Example 17

This example illustrates the effect of adding sodium silicate before or after rehydration (thermal aging) of the calcined alumina slurry.

Calcined alumina (CP-3, ALCOA) was prepared with varying amounts of silicate and then thermally aged for 24 hours under boiling and refluxing conditions to prepare a slurry. The resulting samples were grouped as test 54. It is also possible to use calcined alumina only (known as test 53), or else to add thereto a 3% dispersible hectorite (Laponite) before thermal ageing^*RD) calcined alumina(referred to as run 55) a slurry was prepared. After thermal ageing, the latter two preparations were treated with varying amounts of silicate, the amounts being shown in fig. 8. All samples were exchanged with ammonium sulfate to reduce Na₂O content (< 0.25 wt.%) and then heat treated in about 20% steam at 800 ℃ for 4 hours. The surface areas of the products from runs 53-55 are reported in FIG. 18. The surface area results show that the addition of silicate improves the hydrothermal stability of all samples. However, the surface areas are generally in the following order: al (Al)₂O₃+3％Laponite^*Adding silicate after aging > adding silicate before aging. The addition of silicate prior to thermal aging also reduces the pore volume/pore diameter of the boehmite.

Example 18

This example illustrates the addition of silicate to the steamed boehmite alumina/Laponite after rehydration^*The pore structure of the composite.

Preparation of the silicate amounts 0% (test 56), 2% (test 57), 4% (test 58) and 8% (test 59) by weight of 3% Laponite^*Boehmite samples according to (1). The nitrogen method pore size distribution was measured after treatment in 20% steam at 800 ℃ for 4 hours. The results are reported in fig. 19. Figure 19 shows that there is only a small change in pore distribution with the addition of 0, 2, 4% silicate, but that at 8% silicate the pores shift to a lower average pore size.

Example 19

This example illustrates the preparation of an alumina/swellable clay composite, which was used to make briquettes in the following examples. 7.014 g of synthetic hectorite Laponite of OB (original reference for uncorrected TV) were mixed at room temperature^*(3 wt% based on the total weight of alumina and clay) was slurried in 350 gallons of municipal water. The slurry was stirred in an open tank equipped with a 4 blade stirrer at a maximum stirring speed (about 300 rpm) for 30 minutes to ensure good dispersion. Then, to the slurry, Laponite^*To which 234kg (515 lbs) of OB in Alcoa was slowly addedCP-3 activated alumina. After all CP-3 was added, the slurry was added to 93.3 deg.C (200 deg.F) and incubated for 24 hours. The slurry was filtered and washed with city water at 65.6-71.1 deg.C (150 ℃ F. and 160 deg.F.) in a three wash zone Eimco belt filter. The filter cake was spray dried at 371.1 ℃ (700 ° F) inlet/121.1 ℃ (250 ° F) outlet temperature.

The resulting product was designated as sample No. AX-1.

The properties of AX-1 are summarized in Table 11, and its nitrogen method pore size distribution curve is shown in FIG. 20. The data for AX-1 in FIG. 20 is referred to as trial 60.

Comparative example 3

Comparative samples of boehmite alumina were synthesized as follows.

To 4,950 parts by volume of continuously stirred water heated to 63.3 deg.C (146 deg.F) in the reactor was added 150 parts by volume of a 7.0% by weight aluminum sulfate solution as alumina and the resulting mixture was stirred for 4 minutes. Two separate solutions were then fed simultaneously into the reactor. The first solution was 7.0 wt.% aluminum sulfate, calculated as alumina in water, and the second solution was 20 wt.% aluminum, calculated as Al in water₂O₃And (4) counting the sodium aluminate. When the addition was complete, the weight ratio of aluminum sulfate to sodium aluminum sulfate in the reactor was 5: 3. The flow rate was adjusted during the addition to provide a pH of 7.6. When the target pH of 7.6 is met, the addition of aluminum sulfate is stopped and the addition of sodium aluminate is continued until a pH of 9.3 is reached. The addition of sodium aluminate is then stopped and the reactor contents aged at 66 deg.C (150 deg.F) for 2 hours. The precipitated product was then filtered, washed with water and spray dried at 371 ℃ (700 ° F) inlet temperature/135 ℃ (275 ° F) outlet temperature to form aluminum powder, which was size controlled to particle size of 10-20 microns. The resulting product is called CAX-1. The properties are summarized in table 11 and fig. 20. The data for CAX-1 in FIG. 20 is referred to as run 61.

TABLE 11

Test number		60	61
				Sample numbering		AX-1	CAX-1
V at 1750 ℃ F. (about 954.40 ℃ C.)	wt.％	22.0	29.4
				Surface area	m2/g	291	292
Pore volume by nitrogen method (0.967p/p degree)	ml/g	1.16	0.94
				DPI		n/a	31
APS	μ	9.8	15.9
				Na2O	wt.％	0.41	0.03
SO4	wt.％	0.04	0.82
				Fe	wt.％	0.05	0.01
Maximum value of mesopore	*	150	65.7
				Increase in mesopore size by several% to the maximum	％	60	N/A

As can be seen from Table 11 and FIG. 20, AX-1 (run 60) and CAX-1 (run 61) have similar surface areas. However, AX-1 has a pore volume of about 20% by volume greater than CAX-1, and the mesopore porosity of AX-1 is up to about 150 angstroms, compared to 50-70 angstroms for CAX-1.

Example 20

Part A:

this example illustrates the preparation of pre-impregnated AX-1 prior to extrusion.

13.6kg (30 lbs) of OB AX-1 alumina was mixed in an Eirich mixer with 10.5kg municipal water, 6.2kg ammonium molybdate solution and 2.0kg technical grade (15% Ni) nickel nitrate solution. The ammonium molybdate solution was prepared by dissolving 2.2kg of commercial ammonium dimolybdate crystals in 4.0kg of deionized water. The mixture was extruded in a 4 "Bonnot pilot plant extruder using conventional extrusion conditions to form 0.04" diameter extrudates. The extrudate was dried at 121.1 deg.C (250 deg.F) for 4 hours and calcined at 648.9 deg.C (1200 deg.F) for 1 hour. The resulting extrudate was designated EMAX-1 (run 62).

And part B:

the results of the porosity properties of part a of example 20 were normalized to a metal-free basis and the results were referred to as run 63. The samples are normalized herein to a metal-free basis according to the following equation:

(equation 6)

Wherein: x is the relevant pore property such as PV (ml/g), SA (m)²/g)

W is the weight percent of the catalyst promoter metal oxide, such as oxides of Ni, Co and Mo, on the catalyst based on the weight of the porous component of the catalyst. The weight of the non-porous components of the catalyst extrudate, such as the non-porous diluent, is not included in the weight% calculation.

MFB-Metal-free base

Comparative example 4

Part A:

example 20 of part A was repeated, but the sample of AX-1 from example 19 was replaced by the sample of CAX-1 from comparative example 3. The resulting extrudate product was designated EMCAX-1 (run 68).

And part B:

the porosity property results for part a of comparative example 4 were normalized to a metal free basis and the results were referred to as run 69.

The physical and compositional properties of the metal impregnated catalyst samples EMAX-1 and EMCAX-1 are provided in table 12, and the mercury porosimetry pore size distributions and other properties of these samples are provided in tables 13A and B.

Higher SiO should also be noted due to the nature of the dispersible clay contained in AX-1₂And (4) content. The mercury porosimetry pore size distribution curve for each catalyst is shown in figure 21.

It should be particularly noted that the SA and TPV of runs 62 and 68 are similar, however, the pores of run 62 are at most 145 angstroms in value, compared to only 65 angstroms for run 68. These most probable values are very close to those of the starting alumina, which is characteristic of the stabilizing effect of the pre-impregnated metal on the alumina properties. It can also be seen from tables 13A and B that in run 68 the pore size shifted from < 100 to the 100-250 region, and more predominantly to the 130-250 region for run 62. The total surface area and total pore volume of trial 62 was similar to trial 68, although the pores drifted and increased in most probable value.

TABLE 12

Metal prepreg extrudate

Test number		62	64	66	68
						Sample ID		EMAX-1	EMAX-2	EMAX-3	EMCAX-1
Alumina type		AX-1	AX-1	AX-1+ CAX-12 parts and 1 part	CAX-1
						Catalyst Properties
MoO3	wt.％	14.1	14.9	14.1	13.6
						NiO	wt.％	3.1	3.5	3.1	3.3
SiO2	wt.％	0.66	0.61	0.51	0.08
						Na2O	wt.％	0.2	0.18	0.17	0.06
Fe	wt.％	0.01	0.01	0.01	0.08
						Particle diameter	mm	0.98	0.99	1.00	1.00
CBD1Maximum pile-up	lba/ft3(×0.02768g/mm3)	35.4	32.1	34.5	-36
						Crushing strength	lb/mm	2.9	2.5	2.0	1.7

CBD ═ compacted bulk density

Example 21

Part A:

the metal impregnated extrudate of example 20, part a, was made using the alumina sample AX-1 prepared according to example 19, however, the mixture contained an additional 300 grams of water to increase the amount of porosity greater than 250 angstroms in diameter. The resulting extrudate was designated EMAX-2 (run 64).

And part B:

the porosity property results for part a of this example were normalized to a metal free basis and are referred to as test 65 and reported in tables 13A and 13B.

TABLE 13A
																											Total pore volume*
＜100*		＞100*		＞130*		＞150*		＞250		＞500		＞1200		＞1500		＞4000	100-130*		130-250*
																					Test number	Sample (I)	Example or comparative example numbering				cc/g	％	cc/g	％	cc/g	％	cc/g	％	cc/g	％	cc/g	％	cc/g	％	cc/g	％	cc/g	cc/g	％	cc/g	％
62	EMAX-1	Example 20(a)	.26	33	.53	67	.42	53	.34	43	.17	21	.10	13	.07	9	.06	7.6	.03	.13				13.9	.31	31.6
																					63	MFB-EMAX-1	Example 20(b)				.31	32.9	.64	67.1	.51	53.2	.41	43	.21	21.5			.08	8.9	.07	7.6
64	EMAX-2	Example 21(a)	.26	29	.62	70	.50	57	.43	49	.21	24	.13	15	.11	12	.11	12	.04	.15				13.6	.36	33
																					65	MFB-EMAX-2	Example 21(b)				.32	29.5	.76	70.5	.61	56.8	.53	48.9	.26	23.9			.13	12.5	.13	12.5
66	EMAX-3	Example 22(a)	.36	40	.54	60	.44	49	.38	42	.25	28	.17	19	.12	13	.11	12	.04	.12				11.1	.23	21.1
																					67	MFB-EMAX-3	Example 22(b)				.43	40	.65	60	.53	48.9	.46	42.2	.30	27.8			.14	13.3	.13	12.2
68	EMCAX-1	COMPARATIVE EXAMPLE 4(a)	.44	51	.38	44	.33	38	.31	36	.27	31	.24	28	.21	24	.20	23	.15
																					69	MFB-EMCAX-1	COMPARATIVE EXAMPLE 4(b)				.53	53.7	.46	46.3	.40	40.2	.37	37.8	.32	32.9			.25	25.6	.24	24.4
70	EAX-4	Example 23	.22	27.2	.59	72.8	.44	53.9	.24	29.6	.04	4.9	.02	2.5	0	0	0	0	0	.15				18.9	.40	49
																					71	EAX-5	Example 24(a)				.24	27.6	.63	72.4	.48	55.2	.32	36.8	.06	6.9	.03	3.4	.02	2.3	.01	1.1	.01	.15	17.2	.42	48.3
72	ECAX-2	Comparative example 5	.32	33.7	.63	66.3	.38	40.0	.28	29.5	.20	21.1	.17	17.9	.14	14.7	.13	13.7	.06	.25				26.3	.18	18.9
																					73	EMAX-5	Example 24(b)				.11	15.1	.62	84.9	.52	71.2	.43	58.9	.05	6.8	.03	4.1	.02	2.7	.02	2.7	.01	.10	13.7	.47	64.4
74	EMAX-6	Example 25	.16	17.6	.75	82.4	.59	64.8	.50	54.9	.26	28.6	.16	17.6	.10	11.0	.09	9.9	.02	.16				17.6	.33	36.3
																					75	EMCAX-2	Comparative example 6				.18	22.5	.62	77.5	0.42	52	.31	38.8	.18	22.5	.15	18.8	.12	15.0	.12	15.0	.04	0.20	25.5	0.24	29.5

Measured according to Hg porosimetry with contact angle of 140 °.

TABLE 13B
						Test number	Sample (I)	Example or comparative example numbering	The best value of the pore A (dV/dlogD)	SAm2/g(Hg)	TPVcc/g(Hg)
62	EMAX-1	Example 20(a)	148	288	0.86
						63	MFB-EMAX-1	Example 20(b)	148	348	.95
64	EMAX-2	Example 21(a)	135	290	.88
						65	MFB-EMAX-2	Example 21(b)	135	355	1.08
66	EMAX-3	Example 22(a)	119/63	312	.90
						67	MFB-EMAX-3	Example 22(b)	119/63	377	1.09
68	EMCAX-1	COMPARATIVE EXAMPLE 4(a)	67	297	0.82
						69	MFB-EMCAX-1	COMPARATIVE EXAMPLE 4(b)	67	357	.99
70	EAX-4	Example 23	148	212	.81
						71	EAX-5	Example 24(a)	158	222	.87
72	ECAX-2	Comparative example 5	99	201	.95
						73	EMAX-5	Example 24(b)	191	166	.73
74	EMAX-6	Example 25	115	180	.91
						75	EMCAX-2	Comparative example 6	115	192	.80

MFB-Metal-free base

Example 22

Part A

The catalyst was prepared in the same manner as EMAX-1 (run 62), except that the alumina source was a physical powder mixture of 9.09kg (20 lbs) of the Original Batch (OB) of AX-1 (run 60) and 4.5kg (10 lbs) of OB of CAX-1 (run 61). CAX-1 alumina was added to increase the macroporosity (> 250 angstroms) in the catalyst. The resulting product was designated EMAX-3 (run 66) and its properties are summarized in tables 12 and 13A and B, and fig. 21. As can be seen therein, CAX-1 adds pores that increase the < 100 angstrom region and the < 250 angstrom region and becomes bimodal.

Part B

The porosity properties of the samples of part a were normalized to a metal free basis and the results were referred to as test 67 and reported in tables 13A and B.

Example 23

This example describes the process of making an alumina substrate (containing only alumina) for a catalyst that can ultimately be processed into a catalyst by a "post-impregnation" process. The substrate of the post-impregnated catalyst is prepared by extruding/calcining alumina in the absence of promoter metals (Ni and Mo in this case).

30 pounds OB of AX-1 alumina was mixed with 31 pounds of municipal water in a pilot-type Eirich mixer. The mixture was extruded using a 4 "Bonnot extruder to form 0.04" diameter extrudates. The extrudate was dried at 121.1 deg.C (250 deg.F) for 4 hours and then calcined at 732.2 deg.C (1,350 deg.F) for 1 hour.

The resulting product was designated EAX-4 (run 70) and the mercury porosimetry properties are shown in 13A and B.

Comparative example 5

Example 22 was repeated, but the starting alumina was CAX-1. The product obtained is designated ECAX-2 (run 72). Mercury porosimetry properties are shown in tables 13A and B.

Comparing tests 70 and 72, it can be seen that test 70 has almost 70% TPV in the 100-250 angstrom range and most (49%) is in the 130-250 angstrom range. It should also be noted that run 72 shifted the porosity of the starting CAX-1 alumina (run 61) from 65 angstroms to 100 angstroms in the extrudate at best. This is not the case for test 70 (FIG. 22) versus test 60 AX-1 (FIG. 20), both of which exhibit a porosity maximum of about 145 angstroms. Moreover, trial 70 exhibited approximately the same maximum value of porosity as trials 62 and 64 (FIG. 21). Thus, it appears that AX-1 according to the invention has the same porosity values up to a few, whether or not post-impregnated. It should also be noted that trial 70 has substantially no pores greater than 250 angstroms, unlike its pre-impregnated analog of trial 62.

Example 24

Part A

Example 23 was repeated, but 14.5kg (32 pounds) of water (1 pound more than in example 23) was used in the mixture to increase the total porosity in the pores > 250 angstroms. The resulting extrudate was designated EAX-5 (run 71).

The compositional properties, particle size, and crush strength of tests 70-72 are summarized in table 14, and the mercury porosimetry pore distribution of the samples of tests 70-72 are summarized in tables 13A and B. The mercury porosimetry pore distributions of trials 70-72 are also shown in figure 22.

Part B

EAX-5 (run 71) of part A post-immersion of metal-free extrudate samples was as follows:

313g of ammonium molybdate solution adjusted to a pH value of 5.2 to 5.4 were mixed with 120g of nickel nitrate. Water was added to make a total of 440ml of solution. The entire solution was transferred to 550g of EAX-5 substrate. The impregnation is carried out by the incipient wetness technique in a plastic bag. The impregnated material was dried overnight at 121.1 deg.C (250 deg.F) and calcined at 537.8 deg.C (1,000 deg.F) for 1 hour. The resulting catalyst was designated EMAX-5 (run 73) and its mercury porosimetry properties are shown in tables 13A and B.

Comparative example 6

Part B of example 24 was repeated, but the EAX-5 sample was replaced with the extrudate comparative sample ECAX-2 of test 72. The resulting metal impregnated extrudate sample was designated EMCAX-2 (test 75) and its mercury porosimetry properties are shown in tables 13A and B.

Example 25

Example 22 was repeated, but the mix consisted of equal amounts of AX-1 and CAX-1, each of 6.8kg (15 lbs). The mix was mixed with 31 lbs of water in an Eirich mixer and the nickel and molybdenum impregnated with the metal solution prepared according to example 24, part B, but the total volume of the solution was 550ml due to the higher pore volume of the present sample.

The resulting metal impregnated extrudate was designated EMAX-6 (test 74) and its mercury porosimetry properties are shown in tables 13A and B.

The compositional properties, particle size, bulk density and crush strength of runs 73-75 are summarized in Table 15.

TABLE 14

Examples of Metal-free substrates

Test number		70	71	72
					Specimen ID		EAX-4	EAX-5	ECAX-2
Alumina type		AX-1	AX-1	CAX-1
					Catalyst Properties
MoO3	wt.％		Contains no metal
					NiO	wt.％		Contains no metal
SiO2	wt.％	0.2	0.2	0.01
					Na2O	wt.％	0.41	0.41	0.03
Fe	wt.％	0.05	0.05	0.01
					Particle diameter	mm	0.99	0.97	1.02
Crushing strength	lb/mm	1.96	1.55	1.74

Watch 15

Examples after impregnation

Test number		73	74	75
					Specimen ID		EMAX-5	EMAX-6	EMCAX-2
Alumina type		AX-1	AX-1+ CAX-1 equal parts	CAX-1
					Catalyst Properties
MoO3	wt.％	13.5	13.3	13.3
					NiO	wt.％	3.5	3.4	3.5
SiO2	wt.％	0.65	0.24
					Na2O	wt.％	0.17	0.11
Fe	wt.％	0.01	0.01
					Particle diameter	mm	0.99	0.99
CBD, maximum Stacking	lb/cf(×0.02768g/mm3)	39.6	33.7	36.8
					Crushing strength	lb/mm	1.64	1.84

Example 26

Vacuum tower residuum (VTB) from arabian medium crude oil having the properties summarized in table 16 was selected as the feedstock for the fixed bed residuum hydrogenation test unit. The operating conditions of the test apparatus are summarized in table 17.

The catalyst from run 62(EMAX-1) was placed in a test cell and tested as described below. The test unit had 4 separate reactors in a common sand bath. The sand bath maintained 4 reactors at about the same temperature. Each reactor was charged with 75ml of the catalyst to be tested. Inert glass beads are placed above and below the catalyst bed to preheat the reactants to the desired conditions and take up any additional space. Hydrogen and resid feed enter the bottom of the reactor and flow together up through the catalyst bed, exiting the top of the reactor. The product enters a gas-liquid separator, which is located downstream of the reactor. The gaseous product is passed through the system through a pressure control valve that is used to control the reactor pressure. The liquid product passes from the separator through a liquid control valve to a liquid product container which accumulates the product until it is removed from the system. The flow of hydrogen to the reactor was controlled with a mass flow controller. The flow of the residuum feedstock to the reactor was controlled by a feed pump. The temperature of the reactor was controlled by varying the temperature of the sand bath.

The catalyst was tested under the following reference conditions: LHSV was 1.0(75ml/hr feed and 75ml catalyst bed volume), reaction temperature was 426.7 deg.C (800 deg.F) and 2000psig H₂And (4) pressure. The hydrogen flow rate was maintained at 75 Normal Liters (NL)/hour (note: NL was measured at 0 ℃ and 1 atmosphere). These conditions produce about the same conversion levels and sulfur and conradson carbon removal as expected for conventional catalysts in commercial ebullated bed hydrocracking reactors. The percent conversion of material boiling above 537.8 ℃ (1000 ° F) to material boiling below 537.8 ℃ was measured as a function of time and expressed as barrels of feed processed per pound of loaded catalyst.

The results are shown in figure 23 and are referred to as trial 76.

Comparative example 7

Example 26 was repeated but the catalyst from run 68 was used instead of the catalyst from run 62.

The conversion results are also summarized in fig. 23 as run 77. As can be seen in FIG. 23, the AX-1 produced sample of run 76 exhibited a higher activity for cracking high boiling (1000+ ° F) resid species to lighter products than the comparative CAX-1 produced sample of run 77. The data shown is corrected to standard operating conditions to exclude any fluctuations resulting from variations in actual operating conditions. The AX-1 produced catalyst of run 76 also had activity advantages for saturation (product API increase), desulfurization and Conradson carbon residue removal. Theoretically, the higher cracking and hydrogenation activity of such catalysts is due to the improved pore size distribution and possibly to the chemical composition of the substrate produced from the AX-1 starting material.

For test 76, the deposit and metal removal was slightly worse than for the comparison of test 77. At higher bottoms conversion, increased deposits are expected. The test 76 sample also had a lower porosity in the macropore range, which may also affect the deposit and metal properties of the feedstock.

TABLE 16

Properties of the raw materials

Raw materials	Arabic middle-quality vacuum oil residue
			ID number	F94-71	F98-559
API at 60 ℃ F. (about 15.6 ℃ C.)	4.87	5.60
			S.G at 60 ℃ F. (about 15.6 ℃ C.).	1.0376	1.0321
Sulfur, wt.%	5.88	4.72
			Total nitrogen, wt.%	0.41	0.34
Basic nitrogen, wt.%	0.043	0.12
			Conradson carbon residue, wt.%	23.2	26
Pentane insolubles, wt%	27.0	22.9
			Toluene insolubles,% by weight	0.06	0.16
Metal (ppm)
			Ni	36.8	29.4
V	118.3	103.3
			Fe	7	43.9
Zn	2.1	2
			Ca	21	7
Na	5.6	21
			K	1.4	1.1
Distillate:
			LV％＞1000°F	87	97

TABLE 17

Pilot plant operating conditions

Original number: arab Med VTB

Pressure: 2000psig (about 70.31g/cm2)

Rx temperature: 790 ℃ F. (about 477 ℃ C.) (near isothermal)

Feeding speed: 75ml/h

Once introduction of H₂Quantity: 75NL/hr (6000SCFB)

Operation time: about 3 weeks (about 2.0bbl/lb)

Upstream regime

Catalyst loading: 75ml of

LHSV (catalyst base)

Glass bead segment

Providing a reactor space free of catalyst

Simulation of the Industrial catalyst/Hot space ratio

Example 27

Example 24 was repeated, but the catalyst of the comparative example was replaced by the catalyst from run 64(EMAX-2) and the feedstock was another Arabian medium vacuum residue, the properties of which are summarized in Table 16. The results are grouped as test 78 and the conversion performance is summarized in figure 24.

Example 28

Example 27 was repeated using the catalyst of run 66 (BMAX-3) and the results were grouped as run 79 and are shown in FIG. 24.

Comparative example 8

Example 27 was repeated using the comparative catalyst of run 68 (EMCAX-1). The results are grouped into trial 80 and are shown in figure 24.

As can be seen in fig. 24, runs 78 and 79 are superior to the comparative catalyst in conversion.

And, wherein:

(a) total liquid product API, comparative catalyst is inferior to run 79 but superior to run 78;

(b) sulfur reduction-comparative catalyst is inferior to test 79 but superior to test 78;

(c) weight percent Conradson Carbon Residue (CCR) reduction-comparative catalyst is inferior to test 79 but superior to test 78;

(d) deposit reduction-comparative catalysts are superior to tests 78 and 79, and test 79 is better than test 78;

(e) vanadium reduction-the comparative catalyst is superior to runs 78 and 79, and run 79 is superior to run 78;

(f) nickel reduction-the comparative catalyst was inferior to test 79 but superior to test 78.

It should be noted that CCR is the carbonaceous material remaining after vaporization of all light hydrocarbons. It is determined by a standard dry distillation test (ASTM (D-189) which is carried out on the feedstock and product.

The principles, preferred embodiments, and modes of operation of the present invention have been described in the foregoing specification. However, the invention which is intended to be protected herein should not be limited to the particular forms disclosed, since these should be regarded as illustrative rather than restrictive. Variations and changes may be made by those skilled in the art without departing from the spirit of the invention.

Claims (29)

1. Porous composite particles comprising an alumina component and a swellable clay component well dispersed in the alumina component, wherein in the composite particles:

(A) the alumina component comprises at least 75% by weight alumina, at least 5% by weight of the alumina being in the form of crystalline boehmite, gamma alumina derived from crystalline boehmite, or a mixture thereof;

(B) the swellable clay component is dispersible prior to incorporation into the composite particles and is present in the composite particles in an amount (i) less than 10 weight percent based on the total weight of the alumina component and the swellable clay component, and (ii) effective to increase at least one of the hydrothermal stability, nitrogen pore volume, and nitrogen mesopore pore maximum value of the composite particles relative to the corresponding hydrothermal stability, pore volume, and mesopore pore maximum value of the alumina component in the absence of the swellable clay; and

(C) the composite particles have an average particle size of 1 to 150 microns.

2. The porous composite particles of claim 1, calcined at 537.8 ℃ for 2 hours, having:

(i) at least 200m²Specific surface area per gram;

(ii) an average nitrogen method pore diameter of 60-400 angstroms; and

(iii) a total pore volume by nitrogen method of 0.5-2.0 ml/g.

3. The porous composite particles of claim 1 wherein the alumina component is derived from rehydrated activated alumina and the swellable clay component is present in the composite in an amount of 1 to 9 wt%, based on the total weight of swellable clay component and alumina component.

4. The porous composite particles of claim 3 wherein the swellable clay component comprises montmorillonite.

5. The porous composite particles of claim 4 wherein the smectite clay is selected from the group consisting of montmorillonite, hectorite and saponite.

6. The porous composite particles of claim 5 wherein said montmorillonite is a natural or synthetic hectorite.

7. The porous composite particles of claim 6 wherein said montmorillonite is synthetic hectorite.

8. The porous composite particles of claim 4 wherein said swellable clay component is present in an amount of 2 to 7 weight percent based on the total weight of said alumina and swellable clay component.

9. The porous composite particles of claim 2 having an average nitrogen method pore size of 70-275 angstroms, 240-350m²Surface area per gram, total nitrogen pore volume of 0.6 to 1.8ml/g, and nitrogen mesopore pore size of 60 to 300 angstroms.

10. The porous composite particles of claim 1 additionally comprising 0.1 to 40 weight percent silicate, based on the total weight of silicate, alumina component and swellable clay component.

11. Porous composite particles comprising an alumina component and a swellable clay component well dispersed in the alumina component, which after calcination at 537.8 ℃ for 2 hours have:

(A) at least 200m²Specific surface area per gram;

(B) an average nitrogen method pore diameter of 60-300 angstroms; and

(C) total pore volume by nitrogen method of 0.5-2.0ml/g

And is characterized by having:

(I) a macropore content of no more than 40% of the total pore volume;

(II) a mesopore content of 20-90% of the total pore volume of the nitrogen process and wherein the pores in the mesopore range are at least 100-400 angstroms; and

(III) a micropore content of no more than 80% of the total pore volume of the nitrogen process; and is

Wherein, in the composite particles:

(i) the alumina component comprises at least 75% by weight alumina, at least 5% by weight of the alumina being in the form of crystalline boehmite, gamma alumina derived from crystalline boehmite, or a mixture thereof;

(ii) the swellable clay component is dispersible prior to incorporation into the composite particles and is present in the composite particles in an amount (i) less than 10 weight percent based on the total weight of the alumina component and the swellable clay component, and (ii) effective to increase at least one of the hydrothermal stability, nitrogen pore volume, and nitrogen mesopore pore maximum value of the composite particles relative to the corresponding hydrothermal stability, pore volume, and mesopore pore maximum value of the alumina component in the absence of the swellable clay; and

(iii) the composite particles have an average particle size of 1 to 150 microns.

12. A method of making porous composite particles, comprising:

(A) forming a non-colloidal dispersion comprising at least one alumina component and at least one swellable clay in a liquid dispersion medium, said alumina component comprising at least 75 wt.% activated alumina;

(B) rehydrating the active alumina of the alumina component in the presence of the dispersed swellable clay to convert at least 5 wt.% of the active alumina to crystalline boehmite and form composite particles comprising an effective amount of swellable clay well dispersed in the alumina component, the effective amount of swellable clay being (i) less than 10 wt.%, based on the total weight of the alumina component and swellable clay component, and (ii) sufficient to increase at least one of the hydrothermal stability, nitrogen pore volume, and nitrogen mesopore pore maximum value of the composite particles relative to the corresponding hydrothermal stability, pore volume, and mesopore pore maximum value of the alumina component in the absence of the swellable clay;

(C) recovering the composite particles from the dispersion; and

(D) optionally calcining the recovered composite particles at a temperature of 250 ℃ and 1000 ℃ for 0.15 to 3 hours.

13. The process of claim 12 wherein the alumina component of (a) comprises at least 90% by weight alumina derived from the rehydration of activated alumina, the swellable clay component comprises at least one smectite clay present in the dispersion in an amount of 1 to 8% by weight, the rehydration being controlled to convert 30 to 100% by weight of the activated alumina to boehmite, based on the total weight of the alumina component and swellable clay component, with a crystallite size of less than 110 angstroms and the liquid dispersion medium is water.

14. The method of claim 13 wherein the smectite clay is selected from the group consisting of montmorillonite, hectorite and saponite.

15. The method of claim 14, wherein the montmorillonite is a natural or synthetic hectorite.

16. The method of claim 15 wherein the hectorite is at least one synthetic hectorite present in the dispersion in an amount of from 3 to 6 percent by weight.

17. The method of claim 16, wherein the synthetic hectorite has a total volatiles content of 6 to 30 percent by weight.

18. The method of claim 17, wherein the swellable clay component is pre-milled prior to being contacted with the alumina component.

19. The method of claim 13, wherein the alumina component is pre-milled prior to contacting with the swellable clay component.

20. The method of claim 13, wherein 0.1 to 40 weight percent silicate is provided to the dispersion after rehydration of the activated alumina, based on the total weight of silicate, alumina component and swellable clay component, to improve the hydrothermal stability of the composite particles.

21. The method of claim 13 wherein the swellable clay component and alumina component are pre-milled as a mixture prior to rehydration of the active alumina component.

22. The porous composite particles of any one of claims 1-11, wherein the porous composite particles are in the form of agglomerates and have a particle size of 0.5-5 mm.

23. The porous composite particles of claim 22 wherein said alumina component comprises at least 7.5 wt% crystalline boehmite, gamma alumina derived from said crystalline boehmite, or mixtures thereof, said swellable clay component being present in said agglomerate composition particles in an amount of 2-7 wt% based on the total weight of said swellable clay component and alumina component.

24. The porous composite particles of claim 22 wherein said swellable clay is present in an amount of 3 to 6 weight percent based on the total weight of said alumina and swellable clay component.

25. The porous composite particle of claim 22 wherein said surface area is 150-350m²The mercury method has a total pore volume of 0.6-1.5ml/g and a maximum pore size of 65-275 angstrom.

26. The porous composite particles of claim 22 further comprising from 2 to 10 weight percent of a silicate well dispersed in said constituent particles, based on the total weight of silicate, alumina component and swellable clay component.

27. The composite particles of claim 22 impregnated with an amount of at least one catalyst component effective to hydroprocess a petroleum feedstock.

28. Porous composite particles comprising an alumina component and a swellable clay component well dispersed in the alumina component, which after calcination at 537.8 ℃ for 2 hours have:

(A) at least 200m²Specific surface area per gram;

(B) an average nitrogen method pore diameter of 60-300 angstroms;

(C) a total pore volume by nitrogen method of 0.5-2.0 ml/g;

the preparation method comprises the following steps:

(I) forming a non-colloidal dispersion comprising at least one alumina component and at least one swellable clay in a liquid dispersion medium, said alumina component comprising at least 75 wt.% activated alumina;

(II) rehydrating the active alumina of the alumina component in the presence of the dispersed swellable clay so as to convert at least 5 wt.% of the active alumina to crystalline boehmite and form composite particles comprising an effective amount of swellable clay well dispersed in the alumina component, the effective amount of swellable clay being (i) less than 10 wt.%, based on the total weight of the alumina component and swellable clay component, and (II) sufficient to increase at least one of the hydrothermal stability, nitrogen pore volume, and nitrogen mesopore pore maximum values of the composite particles relative to the corresponding hydrothermal stability, pore volume, and mesopore pore maximum values of the alumina component in the absence of the swellable clay;

(III) recovering the composite particles from the dispersion.

29. The porous composite particles of claim 28 prepared by calcining the recovered composite particles in a further calcination step at a temperature of 250-1000 ℃ for 0.15 to 3 hours.