WO2011075286A1

WO2011075286A1 - Process for making boehmite alumina, and methods for making catalysts using the same

Info

Publication number: WO2011075286A1
Application number: PCT/US2010/057591
Authority: WO
Inventors: Ranjit Kumar
Original assignee: W. R. Grace & Co.-Conn.
Priority date: 2009-12-17
Filing date: 2010-11-22
Publication date: 2011-06-23
Also published as: AR079475A1; TW201130739A

Abstract

This invention comprises a novel process for making boehmite alumina and comprises selecting an alumina, and heating it in the presence of an alkali metal hydroxide concentration of at least 0.2 mole per mole of the selected alumina. The heating is conducted at a temperature of at least 100 C and preferably carried out under steam in an autoclave. The boehmite alumina recovered from this process is particularly suitable as active matrix in catalysts used in hydrocarbon conversion processes, especially fluidized catalyst cracking processes for converting hydrocarbon feedstock into gasoline and other petroleum products.

Description

PROCESS FOR MAKING BOEHMITE ALUMINA, AND METHODS FOR MAKING CATALYSTS USING THE SAME

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of the filing date of United States

Provisional Patent Application No. 61/287257 filed December 17, 2009, the disclosure of which is hereby incorporated herein by reference.

FIELD OF THE INVENTION

[0002] This invention relates to boehmite alumina and methods for making the same. The invention also relates to processes for making catalysts from boehmite alumina, especially particulated catalysts suitable for use in fluidized catalytic cracking processes.

BACKGROUND

[0003] Boehmite alumina, also called alpha-alumina monohydrate, is one of the more frequently used aluminum oxide-hydroxide materials in industry. These materials are used as ceramics, abrasive materials, fire-retardants, adsorbents, catalysts, and fillers in composites, etc. A significant portion of the commercial boehmite aluminas is used in catalytic applications such as cracking catalysts, and in particular those used in fluidized catalytic cracking (FCC) processes. Aluminas are themselves catalytically active, but are typically combined with other catalytically active species to make a final catalyst. In cracking catalysts, zeolites are frequently used as the primary catalytic species. The final form of cracking catalysts vary, but regardless of their form, the boehmite alumina will typically affect the performance of the catalyst during the cracking process.

[0004] Boehmites are most commonly manufactured via processes involving neutralization of aluminium salts by alkali or acidification of aluminate salts, hydrolysis of aluminium alkoxides, reaction of aluminium metal (amalgamated) with water and rehydration of amorphous rho-alumina obtained by flash-calcining aluminium trihydrate.

[0005] The pH and the temperature of the suspensions during aging in the above processes affect the final properties of the boehmites produced. The crystallization rate, for example, increases with pH and temperature. See US Patent Application 2007/0274903. The '903 patent application describes making boehmite alumina by aging and/or processing boehmite alumina precursors under hydrothermal conditions. See also, US 2008/0031808; US 6,555,496; and US 2006/0096891. The latter '891 application teaches adding pH adjusters, e.g., potassium and/or sodium hydroxide, to the above aging steps.

[0006] The '903 patent application also discloses addition of sodium hydroxide, apparently for the purpose of controlling the type of crystalline product produced. The '903 patent, for example, is directed to making quasi crystalline boehmite, and the pH of the slurry, and therefore the amount of pH adjuster, is adjusted and selected to favor preparation of quasi crystalline boehmite, as opposed to microcrystalline boehmite. The examples of the '903 applications manipulate the pH by first adding acid to lower the pH and then raise the pH by adding alkali. The alkali metal, however, is believed to mostly form a salt with the anion of the acid added, therefore any excess alkali metal only resulting in alkali hydroxide concentrations of about 0.02 moles per mole of alumina. See Example 10 below.

[0007] As mentioned above, alumina is frequently used to make cracking catalysts, and in particular FCC catalysts. Alumina is an active component of the catalyst in addition to providing bulk and surface area to the final catalyst. Therefore, while alumina can favorably affect product yields from the FCC process, including gasoline fractions, alumina can also detrimentally affect other parameters in the process, such as generation of hydrogen gas, and the amount of hydrocarbon residue (coke) depositing on the catalyst, which in turn decreases the yield of useful products. It therefore would be desirable to develop and utilize alumina that, on balance, favorably affects these properties.

SUMMARY OF THE INVENTION

[0008] The invention comprises making boehmite by heating alumina in the presence of alkali metal hydroxide at concentrations higher than previously attained by alkali used as a pH control additive. Specifically, the process comprises:

(a) selecting an alumina, (b) placing the alumina in medium for heating the same,

(c) heating the alumina at a temperature of 100°C or higher in the presence of alkali metal hydroxide at a concentration of at least 0.20 mole per mole of alumina, and

(d) recovering boehmite alumina from the medium after heating.

[0009] The heating is typically at a temperature in the range of 100 to 300°C, and preferably in the presence of steam, e.g., in an autoclave. It would be typical to treat the alumina at alkali metal hydroxide concentrations in the range of 0.2 to 2.20 moles per mole alumina when using the invention.

[0010] It is has been shown that the boehmite alumina prepared in accordance with the method above is particularly suitable for making catalysts, especially catalysts used in fluid catalytic cracking (FCC) processes. Therefore, the invention further comprises methods for making catalyst, especially FCC catalysts, wherein the process comprises:

(a) selecting alumina,

(b) placing the alumina in medium for heating the same,

(c) heating the selected alumina at a temperature of 100°C or higher in the presence of alkali metal hydroxide at a concentration of at least 0.20 mole per mole alumina,

(d) recovering boehmite alumina from the medium after heating,

(e) combining the recovered alumina with catalytic species or

material, and

(f) processing the combination of the recovered alumina and catalyst species or material (other than the recoved boehmite alumina) into a finished catalyst form.

[0011] One or more optional materials, such as matrix, binder and/or functional additives, may be included in (e) when the catalytic species and/or material is processed with the alumina of this invention to make the final catalyst. The catalytic species for FCC catalysts generally comprise zeolite, and the finished FCC catalyst is typically particulate having an average particle size in the range of 20 to 150 microns. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a graph illustrating the amount of coke (weight %) depositing during a simulated FCC process (ACE) utilizing catalyst containing various embodiments of alumina made by the invention (Examples 2-4 below) versus the conversion rate (weight %) of the hydrocarbon during the FCC process. The inventive alumina was prepared from boehmite alumina, and the catalyst prepared from the same is compared to catalyst made from alumina made by prior processes (Example 1 below). ACE refers to a laboratory scale catalyst testing methodology as described in the Examples below.

[0013] Figure 2 is a graph illustrating the amount of hydrogen (weight %) generated during a simulated FCC process (ACE) utilizing catalyst containing various embodiments of alumina made by the invention (Examples 2-4) versus the conversion rate (weight %) of the hydrocarbon during the FCC process. The catalyst prepared with alumina made by the invention is compared to catalyst made from alumina made by prior processes (Example 1).

[0014] Figure 3 is a graph illustrating the amount of gasoline (C₅ and greater olefin fractions) (weight %) in product yield from a simulated FCC process (ACE) utilizing catalyst containing various embodiments of alumina made by the invention (Examples 2-4) versus the conversion rate (weight %) of the hydrocarbon during the FCC process. The catalyst prepared with alumina made by the invention is compared to catalyst made from alumina made by prior processes (Example 1).

[0015] Figure 4 is a graph illustrating the amount of coke (weight %) depositing during a simulated FCC process (ACE) utilizing catalyst containing various embodiments of alumina made by the invention (Examples 6-8 below) versus the conversion rate (weight %) of the hydrocarbon during the FCC process. The inventive alumina was prepared from either gamma alumina or flash calcined gibbsite alumina, and catalyst prepared from the same is compared to catalyst made from alumina made by prior processes (Example 5 below).

[0016] Figure 5 is a graph illustrating the amount of hydrogen (weight %) generated during a simulated FCC process (ACE) utilizing catalyst containing various embodiments of alumina made by the invention (Examples 6-8)versus the conversion rate (weight %) of the hydrocarbon during the FCC process. The inventive alumina was prepared from either gamma alumina or flash calcined gibbsite alumina, and catalyst prepared from the same is compared to catalyst made from alumina made by prior processes (Example 5).

[0017] Figure 6 is a graph illustrating the amount of gasoline (C₅ and greater olefin fractions) (weight %) in product yield from a simulated FCC process (ACE) utilizing catalyst containing various embodiments of alumina made by the invention (Examples 6-8) versus the conversion rate (weight %) of the hydrocarbon during the FCC process. The inventive alumina was prepared from flash calcined gibbsite alumina, and catalyst prepared from the same is compared to catalyst made from alumina made by prior processes (Example 5).

[0018] Figure 7 is a graph illustrating the amount of coke (weight %) depositing during a simulated FCC process (ACE) utilizing catalyst containing various embodiments of alumina made by the invention (Examples 11-13 below) versus the conversion rate (weight %) of the hydrocarbon during the FCC process. The inventive alumina was prepared from gibbsite alumina, and catalyst prepared from the same is compared to catalyst made from gibbsite alumina in accordance with US Patent Application 2007/0274903 (Example 10 below). The catalysts prepared from the inventive alumina (Examples 11-13) were also compared with catalysts prepared from another comparative alumina as illustrated in Example 9.

[0019] Figure 8 is a graph illustrating the amount of hydrogen (weight %) generated during a simulated FCC process (ACE) utilizing catalyst containing various embodiments of alumina made by the invention (Examples 11-13) versus the conversion rate (weight %) of the hydrocarbon during the FCC process. The inventive alumina was prepared from gibbsite alumina, and catalyst prepared from the same is compared to catalyst made from gibbsite alumina in accordance with US Patent Application 2007/0274903 (Example 10). The catalysts prepared from the inventive alumina (Examples 11-13) were also compared with catalysts prepared from another comparative alumina as illustrated in Example 9.

[0020] Figure 9 is a graph illustrating the amount of gasoline (C₅ and greater olefin fractions) (weight %) in product yield from a simulated FCC process (ACE) utilizing catalyst containing various embodiments of alumina made by the invention (Examples 11-13) versus the conversion rate (weight %) of the hydrocarbon during the FCC process. The inventive alumina was prepared from gibbsite alumina, and catalyst prepared from the same is compared to catalyst made from gibbsite alumina in accordance with US Patent Application 2007/0274903 (Example 10). The catalysts prepared from the inventive alumina (Examples 11-13) were also compared with catalysts prepared from another comparative alumina as illustrated in Example 9.

DETAILED DESCRIPTION

[0021] The term "boehmite" has the meaning generally recognized in the refining catalyst industry and other industries, and refers to alumina hydrates that exhibit X-ray diffraction (XRD) patterns close to that of aluminium oxide-hydroxide [AIO(OH)]. There is a wide range of alumina hydrates includable as boehmite. These alumina hydrates have different surface areas, pore volumes, specific densities, and exhibit different thermal characteristics upon thermal treatment. These materials exhibit the characteristic boehmite [AIO(OH)] peaks, but the peaks can vary in their widths and location in the pattern. The sharpness of the XRD peaks and their location are used to indicate the degree of crystallinity, crystal size, and amount of imperfections.

[0022] The phrase "catalytic species or material" refers to precursors, chemicals, functional groups, and any other chemical moiety capable of catalyzing a reaction, especially hydrocarbon conversion reactions known in the art.

[0023] A "finished form" of catalyst refers to a material containing the catalyst species or material that is directly added to the catalyzed reaction, and can be in forms known to those skilled in the art, including particulate, extrudates, monoliths, beads, and the like.

[0024] The term "alkali metal" refers to a Group IA metal, mixtures thereof, or the ionic species of the same as the context herein as may require, e.g., alkali metal hydroxide such as NaOH.

[0025] The alumina selected for the process according to the invention varies depending on the application of the resulting boehmite alumina, and the properties desired for the boehmite alumina, e.g., pore volume, surface area, the type of catalyst species or material with which the alumina is combined, and attrition resistance needed for the final form of the catalyst.

[0026] Aluminas suitable for processing in accordance with any number of embodiments of this invention include, but are not limited to, a member selected from the group consisting of boehmite, calcined transition alumina (e.g., rho, gamma, theta, and eta alumina), pseudoboehmite, disapore alumina, amorphous alumina, flash calcined aluminum trihydrate, gibbsite, bayerite, Nordstandite, and mixture of two or more thereof. Boehmite, gibbsite, and flash calcined gibbsite are particularly suitable aluminas, especially when using the invention to make boehmite aluminas for use in catalyst compositions suitable for use in FCC processes.

[0027] The average particle size of the alumina can vary. Generally the aluminas used for this invention can have an average particle size in the range of 1 to 1000 microns. The alumina, however, may require processing before it is processed in accordance with the invention, including, milling the alumina to a particle size suitable for forming catalyst particles described later below.

[0028] Once an alumina is selected (and optionally processed as needed), it is added to a medium for heating the same. The medium preferably is water, and the alumina is added to the medium in an amount sufficient to have a solids content in the range of 2 to 40% by weight.

[0029] Alkali metal is also added to the medium, either before, after, or simultaneously with the addition of the alumina. A sufficient amount of alkali metal is added so that the alkali metal, in the form of alkali metal hydroxide, is present in the medium at a concentration of at least 0.20 mole per mole of alumina, preferably 0.20 to 2.20, and more preferably in the range of 0.2 to 2. Suitable alkali metal hydroxides include hydroxides of sodium, potassium, lithium, and cesium. Sodium or potassium hydroxides are particularly suitable.

[0030] The pH of the alkali metal hydroxide and alumina-containing medium varies depending on the alkali metal hydroxide concentration, the type of alkali metal and alumina selected. Generally, the pH of the medium is 7 or greater, and in the range of 7 to 14. [0031] The medium containing alkali metal hydroxide and the alumina is heated to a temperature of at least 100°C, and typically at a temperature in the range of 100 to 300°C. The heating to at least 100°C can be in the presence of steam and typically heating to a temperature in the range of 100-300°C, and more typically in the range of 120 to 250°C. The heating in the presence of steam is typically conducted in an autoclave.

[0032] The alumina is generally heated for a period of ten minutes to forty-eight hours, preferably thirty minutes to ten hours.

[0033] Once the alumina is heated for the desired period of time, a boehmite alumina is recovered from the medium, usually through filtering using conventional methods.

[0034] The boehmite alumina prepared according to this invention can be utilized to make a catalyst by combining the recovered alumina with catalytic species or material other than alumina, and then processing the combination of the alumina and catalyst species or material into a finished catalyst form. The alumina is typically processed with other optional components and a catalyst species or material to make the finished catalyst. The alumina prepared in accordance with this invention therefore can be added as an "active matrix" for the catalyst.

[0035] The catalyst species or material for any number of embodiments can be a zeolite, and the catalyst species or material is typically a zeolite when the catalyst is being made for use in a hydrocarbon conversion process, e.g., conventional FCC processes. The zeolite can be any zeolite having catalytic activity in a hydrocarbon conversion process. Generally, the zeolites can be large pore size zeolites that are characterized by a pore structure with an opening of at least 0.7 nm, or zeolites that are characterized by intermediate pore sizes having a pore size smaller than 0.7 nm but larger than about 0.56 nm.

[0036] Suitable large pore zeolites comprise crystalline alumino-silicate zeolites such as faujasite, i.e., type Y zeolite, type X zeolite, and Zeolite Beta, as well as heat treated (calcined) and/or rare-earth exchanged derivatives thereof. Zeolites that are particularly suited include calcined, rare-earth exchanged type Y zeolite (CREY), the preparation of which is disclosed in U.S. Pat. No. 3,402,996, ultra stable type Y zeolite (USY) as disclosed in U.S. Pat. No. 3,293,192, as well as various partially exchanged type Y zeolites as disclosed in U.S. Pat. Nos. 3,607,043 and 3,676,368. Other suitable large pore zeolites include MgUSY, ZnUSY, MnUSY, HY, REY, CREUSY, REUSY zeolites, and mixtures thereof.

[0037] Standard Y-type zeolite is commercially produced by crystallization of sodium silicate and sodium aluminate. This zeolite can be converted to USY-type by dealumination, which increases the silicon/aluminum atomic ratio of the parent standard Y zeolite structure. Dealumination can be achieved by steam calcination or by chemical treatment. In embodiments where clay microspheres are "zeolitized" in situ to form zeolite Y, the zeolite Y is formed from calcined clay microspheres by contacting the microspheres to caustic solution at 180°F (82°C). See Studies in Surface Science and Catalysis, supra.

[0038] The unit cell size of a preferred fresh Y-zeolite is about 24.45 to 24.7 A.

The unit cell size (UCS) of zeolite can be measured by X-ray analysis under the procedure of ASTM D3942. There is normally a direct relationship between the relative amounts of silicon and aluminum atoms in the zeolite and the size of its unit cell. This relationship is fully described in Zeolite Molecular Sieves, Structural Chemistry and Use (1974) by D. W. Breck at Page 94, which teaching is incorporated herein in its entirety by reference. Although both the zeolite, per se, and the matrix of a fluid cracking catalyst usually contain both silica and alumina, the Si0₂/Al₂0₃ ratio of the catalyst matrix should not be confused with that of the zeolite. When an equilibrium catalyst is subjected to x- ray analysis, it only measures the UCS of the crystalline zeolite contained therein.

[0039] The unit cell size value of a zeolite also decreases as it is subjected to the environment of the FCC regenerator and reaches equilibrium due to removal of the aluminum atoms from the crystal structure. Thus, as the zeolite in the FCC inventory is used, its framework Si/Al atomic ratio increases from about 3:1 to about 30:1. The unit cell size correspondingly decreases due to shrinkage caused by the removal of aluminum atoms from the cell structure. The unit cell size of a preferred equilibrium Y zeolite is at least 24.22A, preferably from 24.24 to 24.50A, and more preferably from 24.28 to 24.44A. [0040] Suitable medium pore size zeolites include pentasil zeolites such as ZSM-

5, ZSM-22, ZSM-23, ZSM-35, ZSM-50, ZSM-57, MCM-22, MCM-49, MCM-56 all of which are known materials.

[0041] Other zeolites that may be used include those zeolites with framework metal elements other than aluminum, for example, boron, gallium, iron, chromium.

[0042] The one or more optional additional components in the finished catalyst include, but are not limited to, matrix, binders, and/or functional additives. As mentioned above, the boehmite alumina of this invention can serve as active matrix for the finished catalyst, and to the extent desired, additional matrix materials such as alumina made by processes other than this invention, silica, porous alumina-silica, and kaolin clay may be added. By "active" it is meant the material has activity in converting and/or cracking hydrocarbons, e.g., cracking hydrocarbons in a typical FCC process.

[0043] The matrix material, i.e., the boehmite alumina of this invention and any additional matrix material utilized, may be present in an amount of up to about 90 wt% of the total catalyst composition. The matrix typically is present in an amount ranging from about 20 to about 90 wt %, most preferably, from about 40 to about 80 wt%, of a catalyst composition.

[0044] As mentioned above, kaolin clay is a typical matrix, and when used, the clay component itself can typically comprise about 20 to about 60 wt% of the catalyst composition.

[0045] Suitable binders include those materials capable of binding the matrix and zeolite into particles. Specific suitable binders include, but are not limited to, alumina sols, silica sols, aluminas (including peptized aluminas), and silica aluminas. Suitable binders also include alum-derived binders disclosed in WO 2008/005155, the contents of which are incorporated by reference. The aforementioned materials are in effect binder precursors forming inorganic oxides that serve to bind the other components of the catalyst composition into a final form having the desired properties, including, but not limited, resistance to attrition during use of the composition. It is therefore generally desirable to utilize binders with the invention, and it would be typical to produce particulated catalysts using this invention wherein the catalysts has a Davison Attrition Index in the range of 1 to 20, preferably 1 to 15. [0045] It may be preferable to add rare earth to the catalyst composition to enhance the catalyst's performance in the FCC unit. Suitable rare earth includes lanthanum, cerium, yttrium, praseodymium, and mixtures thereof, which can be added in the form of a salt into a mixture containing the boehmite alumina of this invention and the catalytic species or material, prior to forming the catalyst. Suitable salts include rare earth nitrates, carbonates, and/or chlorides. Rare earth can also be added to the zeolite per se through separate exchanges with any of the aforementioned salts.

[0046] Other optional additives conventionally used as functional additives in catalytic cracking processes include, but are not limited to, SO_x reduction additives, NO_x reduction additives, gasoline sulfur reduction additives, CO combustion promoters, additives for the production of light olefins, and the like. These additives can be formed as separate bound particles and then combined with the boehmite alumima and catalyst species or material prior to forming a catalyst particle. Alternatively, the active functionality of the additive, e.g., vanadium in a gasoline sulfur reduction additive, can be added as a salt, or other soluble form, to the medium in which the alumina and catalyst species are combined. The separately formed additive particles may also be mixed with separate catalyst particles comprising boehmite alumina prepared by the invention.

[0047] When manufacturing FCC catalysts, spray drying can be used to process the boehmite alumina of this invention, catalytic species or material, and optional components to form the finished catalyst. For example, after combining the boehmite alumina and zeolite with any optional components in water, the resulting slurry can be spray dried into particles having an average particle size in the range of about 20 to about 150 microns, more preferably 40 to 100 micron, and the resulting catalyst particulate is then processed under conventional conditions.

[0048] It is optional to then wash the catalyst to remove excess alkali metal, which are known contaminants to catalysts, especially FCC catalysts. It is also possible to wash the boehmite alumina produced by the inventive process prior to any further processing the alumina with catalyst species or material. In either embodiment, the catalyst and/or boehmite alumina is washed one or more times, preferably with water and/or aqueous ammonium salt solutions, such as ammonium sulfate solution. The washed catalyst or recoved boehmite alumina is separated from the wash slurry by conventional techniques, e.g. filtration, and dried to lower the moisture content of the particles to a desired level, typically at temperatures ranging from about 100°C to 300°C.

[0049] The spray dried catalyst is then ready as a finished catalyst "as is", or it can be calcined for activation prior to use. The catalyst particles, for example, can be calcined at temperatures ranging from about 370°C to about 760°C for a period of about 20 minutes to about 2 hours. Preferably, the catalyst particles are calcined at a temperature of about 600°C for about 45 minutes.

[0050] The total surface area for any of the aforementioned embodiments can be in the range of 100 to 500 m 2 /g, more typically in the range of 150 to 350 m 2 /g.

[0051] A particularly suitable process for making FCC catalyst particles therefore comprises

a. selecting boehmite alumina, gibbsite, flash calcined gibbsite alumina, or mixtures thereof,

b. placing the selected alumina in medium for heating the same,

c. heating the selected alumina at a temperature in the range of 100°C to 300°C in the presence of steam and alkali metal hydroxide at a concentration in the range of 0.20 to 2.0 mole per mole of alumina,

d. recovering boehmite alumina from the medium after heating,

e. combining the recovered boehmite alumina with zeolite and one or more components selected from the group consisting of silica, silica-alumina, clay, alumina other than the recovered boehmite alumina, and mixtures thereof, and

f. processing the combination of the alumina and catalyst species or material into a finished catalyst form having an average particle size in the range of 20 to 150 microns.

[0052] Catalytic processes in which catalysts made from the alumina of this invention are well known in the art, and include, without limitation, FCC processes and hydrotreating processes. The catalysts in the former process are generally particulates having an average particle size in the above mentioned range, whereas the latter processes frequently use extrudates having a minimum dimension of 1 millimeter or greater. A description of FCC processes is found in US Patent 7,304,011, the contents of which are incorporated by reference. [0053] To further illustrate the present invention and the advantages thereof, the following specific examples are given. The examples are given as specific illustrations of the claimed invention. It should be understood, however, that the invention is not limited to the specific details set forth in the examples.

[0054] All parts and percentages in the examples, as well as the remainder of the specification, which refers to solid compositions or concentrations, are by weight unless otherwise specified.

[0055] Further, any range of numbers recited in the specification or claims, such as that representing a particular set of properties, units of measure, conditions, physical states or percentages, is intended to literally incorporate expressly herein by reference or otherwise, any number falling within such range, including any subset of numbers within any range so recited.

[0056] The following meanings apply to the abbreviations used in the Examples below.

DB= on a dry basis wherein the material is dried at 1750°F for one hour.

C= temperature in degrees Celsius

Gms or g= grams

m=mole or molar as the context implies

REUSY=rare earth exchanged ultrastable Y zeolite

ppm=parts per million

wt=weight, with "wt%" meaning percentage by weight

XRD=x-ray diffraction

APS=average particle size

ABD=average bulk density

DI=Davison Attrition Index

S A= surface area as measured by BET.

RE= rare earth (e.g., lanthanide metal mixture) EXAMPLES

[0057] The following illustrate processes for making the inventive alumina compared to other processes.

Example 1 (comparison)

[0058] 714 gms DB of boehmite alumina was slurried in 4200 gms of water. The slurry pH was 8.1. The slurry was autoclaved for 1 hour at 188C. After the autoclaving, the slurry was filtered and water washed. The filter cake obtained was slurried in water to 29.5% by weight solids. For XRD small amount of the cake was dried at 120C in a lab oven. XRD analysis confirms that the alumina is a boehmite alumina.

Example 2

[0059] 714 gms DB of boehmite alumina was slurried in 4200 gms of water and then 168 gms of 50% NaOH was added, to obtain 0.3m NaOH per mole of alumina. The slurry pH was 12.8. The slurry was then autoclaved for 1 hour at 188C. After the autoclaving, the slurry was filtered and water washed. The filter cake obtained was slurried in water, and it had 33.7% solids. For XRD small amount of the cake was dried at 120C in a lab oven. XRD analysis confirms that the alumina is a boehmite alumina.

Example 3

[0060] 714 gms DB of boehmite alumina was slurried in 4200 gms of water and then 280 gms. of 50% NaOH was added, to obtain 0.5m NaOH per mole of alumina. The slurry pH was 13.1. The slurry was then autoclaved for 1 hour at 188C. After the autoclaving, the slurry was filtered and water washed. The filter cake obtained was slurried in water, and it had 30.6% solids. For XRD small amount of the cake was dried at 120C in a lab oven. XRD analysis confirms that the alumina is a boehmite alumina.

Example 4

[0061] 714 gms DB of boehmite alumina was slurried in 4200 gms of water and then 392 gms of 50% NaOH was added, to obtain 0.7m NaOH per mole of alumina. The slurry pH was 13.1. The slurry was then autoclaved for 1 hour at 188C. After the autoclaving, the slurry was filtered and water washed. The filter cake obtained was slurried in water, and it had 34% solids. For XRD small amount of the cake was dried at 120C in a lab oven. XRD analysis confirms that the alumina is a boehmite alumina.

Example 5 (comparison)

[0062] 714 gms DB of API 5 alumina was slurried in 4200 gms of water. API 5 alumina is available ALCOA. The slurry pH was 9.3. The slurry was autoclaved for 1 hour at 188C. After the autoclaving, the slurry was filtered and water washed. The filter cake obtained was slurried in water, and it had 36.8% solids. For XRD small amount of the cake was dried at 120C in a lab oven. XRD analysis confirms that the alumina is a boehmite alumina.

Example 6

[0063] 714 gms DB of API 5 alumina was slurried in water and then 168gms of 50% NaOH was added, to obtain 0.3m NaOH per mole of alumina. The slurry pH was 11.7. The slurry was then autoclaved for 1 hour at 188C. After the autoclaving, the slurry was filtered and water washed. The filter cake obtained was slurried in water, and it had 30.9% solids. For XRD small amount of the cake was dried at 120C in a lab oven. XRD analysis confirms that the alumina is a boehmite alumina.

Example 7

[0064] 714 gms DB of AP15 alumina was slurried in water and then 280 gms of 50% NaOH was added, to obtain 0.5m NaOH per mole of alumina. The slurry pH was 12.1. The slurry was then autoclaved for 1 hour at 188C. After the autoclaving, the slurry was filtered and water washed. The filter cake obtained was slurried in water, and it had 21.9% solids. For XRD small amount of the cake was dried at 120C in a lab oven. XRD analysis confirms that the alumina is a boehmite alumina.

Example 8

[0065] 714 gms DB of API 5 alumina was slurried in water and then 392 gms of 50% NaOH was added, to obtain 0.7m NaOH per mole of alumina. The slurry pH was 13.2. The slurry was then autoclaved for 1 hour at 188C. After the autoclaving, the slurry was filtered and water washed. The filter cake obtained was slurried in water, and it had 21.2% solids. For XRD small amount of the cake was dried at 120C in a lab oven. XRD analysis confirms that the alumina is a boehmite alumina.

Example 9 (control)

[0066] The starting gibbsite alumina used in examples 9-13 was in the form of a water slurry. The slurry had 37.8% by weight alumina content.

[0067] 612 gms DB of gibbsite alumina (1619gms as is) was slurried in 3481 gms of water. The slurry pH was 7.32. The slurry was autoclaved for 2 hours at 185C. After the autoclaving, the slurry was filtered and water washed. The filter cake obtained was slurried in water, and it had 24.6% solids. For XRD small amount of the cake was dried at 120C in a lab oven. XRD analysis confirms that the alumina is a boehmite alumina. This preparation and those preparations described in Examples 10-13 were repeated to double the amount of alumina.

Example 10 (example 58 from US 2007/0274903A1)

[0068] 612 gms DB of gibbsite alumina (1619gms as is) was slurried in 3470 gms of water. The slurry pH was 7.32. The pH of the slurry was adjusted to 12 using 50% NaOH solution. The amount of the 50% NaOH used was 9.5gms. The slurry was autoclaved for 2 hours at 185C. After the autoclaving, the slurry was filtered and water washed. The filter cake obtained was slurried in water, and it had 22.5% solids. The NaOH used during this treatment was equal to 0.02m NaOH/m alumina. For XRD small amount of the cake was dried at 120°C in a lab oven. XRD analysis confirms that the alumina is a boehmite alumina.

Example 11

[0069] 612 gms DB of gibbsite alumina (1619gms as is) was slurried in 3337 gms of water. The slurry pH was 7.32. To this slurry 144gms of the 50% NaOH solution was added. The pH of the slurry was 13.41. The slurry was autoclaved for 2 hours at 185C. After the autoclaving, the slurry was filtered and water washed. The filter cake obtained was slurried in water, and it had 17.5% solids. The NaOH used during this treatment was equal to 0.3m NaOH/m alumina. For XRD small amount of the cake was dried at 120C in a lab oven. XRD analysis confirms that the alumina is a boehmite alumina.

Example 12

[0070] 612 gms DB of gibbsite alumina (1619gms as is) was slurried in 3241 gms of water. The slurry pH was 7.32. To this slurry 240gms of the 50% NaOH solution was added. The pH of the slurry was 13.45. The slurry was autoclaved for 2 hours at 185C. After the autoclaving, the slurry was filtered and water washed. The filter cake obtained was slurried in water, and it had 17.2% solids. The NaOH used during this treatment was equal to 0.5m NaOH/m alumina. For XRD small amount of the cake was dried at 120C in a lab oven. XRD analysis confirms that the alumina is a boehmite alumina.

Example 13

[0071] 612 gms DB of gibbsite alumina (1619gms as is) was slurried in 3145 gms of water. The slurry pH was 7.32. To this slurry 336gms of the 50% NaOH solution was added. The pH of the slurry was 13.53. The slurry was autoclaved for 2 hours at 185C. After the autoclaving, the slurry was filtered and water washed. The filter cake obtained was slurried in water, and it had 18.9% solids. The NaOH used during this treatment was equal to 0.7m NaOH/m alumina. For XRD small amount of the cake was dried at 120C in a lab oven. XRD analysis confirms that the alumina is a boehmite alumina.

Preparation of Catalyst Examples 1-13

[0072] All of the following examples contained 30% REUSY, 15% alumina (from Examples 1-8), 35% clay, and 20% silica-sol.

For examples 1-8, the REUSY slurry was 32% solids.

For examples 9-13, the REUSY slurry was 38.2% solids.

The clay contained 85% solids.

The silica-sol contained 10% solids. [0073] The slurry containing REUSY and alumina was milled, and after milling the pH was adjusted to 3.8 using 20% H₂S0₄. To this slurry the silica-sol and clay were added, and the whole slurry was mixed well. The slurry was then spray dried.

[0074] The spray dried catalysts were first slurried at 7-9 pH with NH₄OH, and then exchanged with (NH₄)₂S0₄ solution. The catalysts were finally oven dried.

Catalyst Example 1

[0075] 3177 gms of REUSY slurry, 1723 gms of Example 1 alumina slurry, 6778 gms of silica-sol, and 1395 gms of clay were used to make the catalyst.

Catalyst Example 2

[0076] 3254 gms of REUSY slurry, 1544 gms of Example 2 alumina slurry, 6942 gms of silica-sol, and 1429 gms of clay were used to make the catalyst.

Catalyst Example 3

[0077] 3025 gms of REUSY slurry, 1581 gms of Example 3 alumina slurry, 6454 gms of silica-sol, and 1329 gms of clay were used to make the catalyst.

Catalyst Example 4

[0078] 2922 gms of REUSY slurry, 1375 gms of Example 4 alumina slurry, 6234 gms of silica-sol, and 1283 gms of clay were used to make the catalyst.

Catalyst Example 5

[0079] 3218 gms of REUSY slurry, 1399 gms of Example 5 alumina slurry, 6866 gms of silica-sol, and 1414 gms of clay were used to make the catalyst.

Catalyst Example 6

[0080] 2988 gms of REUSY slurry, 1547 gms of Example 6 alumina slurry, 6374 gms of silica-sol, and 1312 gms of clay were used to make the catalyst.

Catalyst Example 7 [0081] 3048 gms of REUSY slurry, 2226 gms of Example 7 alumina slurry, 6502 gms of silica-sol, and 1339 gms of clay were used to make the catalyst.

Catalyst Example 8

[0082] 3107 gms of REUSY slurry, 2345 gms of Example 8 alumina slurry, 6628 gms of silica-sol, and 1364 gms of clay were used to make the catalyst.

Catalyst Example 9

[0083] 3168 gms of REUSY slurry, 2460 gms of Example 9 alumina slurry, 8068 gms of silica-sol, and 1661 gms of clay were used to make the catalyst.

Catalyst Example 10

[0084] 3542 gms of REUSY slurry, 3007 gms of Example 10 alumina slurry, 9020 gms of silica-sol, and 1857 gms of clay were used to make the catalyst.

Catalyst Example 11

[0085] 3455 gms of REUSY slurry, 3771 gms of Example 11 alumina slurry, 8800 gms of silica-sol, and 1812 gms of clay were used to make the catalyst.

Catalyst Example 12

[0086] 3375 gms of REUSY slurry, 3748 gms of Example 12 alumina slurry, 8596 gms of silica-sol, and 1770 gms of clay were used to make the catalyst.

Catalyst Example 13

[0087] 3429 gms of REUSY slurry, 3465 gms of Example 13 alumina slurry, 8732 gms of silica-sol, and 1798 gms of clay were used to make the catalyst.

Deactivation of the Catalyst Examples 1-13 [0088] Each of the catalyst examples were deactivated, in the presence of lOOOppm Ni + 2000ppm V, using the CPS protocol known in the art. See Lori T. Boock, Thomas F. Petti, and John A. Rudesill, ACS Symposium Series, 634, 1996, 171-183).

[0089] The properties of the Catalysts before and after deactivation from Catalyst Examples 1-13 are reported below in Tables 1-3.

Table 1

Table 3

ACE Performance Evaluation after the deactivation

(0090) The deactivated samples were evaluated in an ACE Model AP Fluid Bed Microactivir unit from ayser Technology, Inc. See also, US Patent 6,069,012. The reactor temperature was 538°C. The feedstock used in the evaluation had the properties provided below.

Properties of the feed used in the ACE testing.

[0091] API means that described in Compositions and Analysis of Heavy Petroleum Fractions, Marcel Dekker, Inc (1994), p. 107. Briefly, it is defined as API = (141.5/[specific gravity of feed at 60°F]) - 131.5.

[0092] Conradson Carbon refers to the coking propensity of a feedstock. See Compositions and Analysis of Heavy Petroleum Fractions, Marcel Dekker, Inc (1994), p. 145, and ASTM D189.

[0093] K Factor is a composite parameter for feedstocks used to estimate the paraffinicity of crude oils. The parameter is based on the average boiling point and specific gravity of the feedstock. See footnote (a) of Compositions and Analysis of Heavy Petroleum Fractions, Marcel Dekker, Inc (1994), p. 115.

[0094] The results from the ACE testing are illustrated in the attached Figures 1-9, showing that catalysts containing the boehmite alumina prepared in accordance with this invention have superior catalyst performance with respect to resulting in lower coke, lower hydrogen for certain emodiments, and higher gasoline yield compared to those catalysts prepared from other aluminas, including those prepared with pH adjusters such as those described in US 2007/0274903.

Claims

What is claimed is:

1. A process for making boehmite alumina, the process comprising:

a. selecting alumina,

b. placing the alumina in medium for heating the same,

c. heating the selected alumina at a temperature of 100°C or higher in the presence of alkali metal hydroxide at a concentration of at least 0.20 mole per mole of alumina, and

d. recovering boehmite alumina from the medium after heating.

2. A process according to claim 1, wherein the alumina in (a) is a member selected from the group consisting of boehmite, calcined transition alumina, pseudoboehmite, bayerite, disapore alumina, flash calcined aluminum trihydrate, gibbsite, amorphous alumina, Norderstandite and mixtures of two or more thereof.

3. A process according to claim 1, wherein the heating in (c) is in the range of 100 to 300°C.

4. A process according to claim 3, wherein the heating is conducted in the presence of steam.

5. A process according to claim 1, wherein the alkali metal of the alkali metal hydroxide is selected from the group consisting of sodium, potassium, lithium, cesium and mixtures thereof.

6. A process according to claim 1, wherein the alkali metal of the alkali metal hydroxide comprises sodium, potassium, or mixture thereof.

7. A process according to claim 1, further comprising (e) removing alkali metal from the recovered boehmite alumina.

8. A process according to claim 1, wherein the alkali metal hydroxide is at a concentration in the range of 0.20 to 2.20 moles per mole of alumina.

9. A process for making catalyst, the process comprising:

a. selecting alumina,

b. placing the alumina in medium for heating the same,

c. heating the selected alumina at a temperature of 100°C or higher in the presence of alkali metal hydroxide at a concentration of at least 0.20 mole per mole of alumina,

d. recovering boehmite alumina from the medium after heating,

e. combining the recovered boehmite alumina with catalytic species or material other than the recovered boehmite alumina, and

f. processing the combination of the alumina and catalyst species or material into a finished catalyst form.

10. A process according to claim 9, wherein the process further comprises removing alkali metal from the recovered boehmite alumina.

11. A process according to claim 10, comprising removing the alkali metal from the recovered boehmite alumina prior to combining it with the catalytic species or material via washing.

12. A process according to claim 10, comprising removing the alkali metal from the recovered boehmite alumina after processing the combination of the alumina and catalyst species or material into a finished catalyst form.

13. A process according to claim 9, wherein one or more additional components are combined with the recovered alumina and catalyst species or material in step (d), the additional components comprising a member of the group consisting of matrix, binder, and additives.

14. A process according to claim 13, wherein the one or more additional components comprise a component selected from the group consisting of clay, silica alumina, silica, and mixtures thereof.

15. A process according to claim 9, wherein the catalyst species or material comprises zeolite

16. A process according to claim 15, wherein the zeolite is selected from the group consisting of USY, REUSY, faujisite, ZSM5 and mixtures thereof.

17. A processing according to claim 9, wherein the alumina in (a) is selected from the group consisting of boehmite, calcined transition alumina, pseudoboehmite, disapore alumina, flash calcined aluminum trihydrate, gibbsite, amorphous alumina, bayerite, Nordstandite, and mixtures of two or more thereof.

18. A process according to claim 9, wherein the heating in (c) is in the range of 100 to 300°C.

19. A process according to claim 18, wherein the heating is conducted in the presence of steam.

20. A process according to claim 9, wherein the alkali metal of the alkali metal hydroxide is selected from the group consisting of sodium, potassium, lithium, cesium and mixtures thereof.

21. A process according to claim 9, wherein the alkali metal of the alkali metal hydroxide comprises sodium, potassium, and mixture thereof.

22. A process according to claim 9, wherein the alkali metal hydroxide is at a concentration in the range of 0.20 to 2.20 mole per mole of alumina.

23. A process according to claim 9, wherein the alumina in (a) is selected from the group consisting of boehmite, gibbsite, flash calcined gibbsite, and mixtures thereof; the heating in (c) is in the range of 100 to 300°C in the presence of steam and alkali metal hydroxide concentration in the range of 0.20 to 2.0; the catalyst species in (e) comprises zeolite, and one or more additional components are combined with the recovered alumina and zeolite, wherein the one or more additional components is selected from the group consisting of silica, silica-alumina, clay, alumina other than that recovered and mixtures thereof; and the combination of the selected alumina, zeolite and one or more additional component are processed in (f) into particulates having an average particle size in the range of 20 to 100 microns.

24. A process according to claim 23, wherein the alkali metal is removed from the boehmite alumina prior to combining it with the catalytic species or material via washing, or the alkali is removed from the particulates via washing the particulate.