CA1217756A

CA1217756A - Demetallization catalyst and process for metals- containing hydrocarbon feedstocks

Info

Publication number: CA1217756A
Application number: CA000457674A
Authority: CA
Inventors: Virginia A. Malik; Allen S.U. Li; Michael C. Chervenak; Richard M. Eccles
Original assignee: HRI Inc
Current assignee: HRI Inc
Priority date: 1983-08-10
Filing date: 1984-06-28
Publication date: 1987-02-10
Also published as: FR2550544B1; JPS6054735A; IT8448692A0; SE8403958D0; SE461336B; FR2550544A1; IT1181820B; SE8403958L; DE3428924A1; IT8448692A1; DE3428924C2; MX172236B

Abstract

ABSTRACT OF THE DISCLOSURE

A particulate synthetic catalyst material composed of sub-stantially aluminum oxide promoted with 0.5-10 W % total metal and having total pore volume of 0.350-0.500 cc/gm for use in demetallization and hydroconversion processes for metals-containing hydrocarbon feedstocks. The catalyst material is preferably spherical shaped and provides a narrow differential size range having a particle equivalent diameter ratio range for larger to smaller particles of about 1.2-2.0, and a preferred nominal 12-18 mesh (U.S. Sieve Series) particle size range. The catalyst can be advantageously used in an ebullated bed reactor in a hydro-demetallization process for hydrocarbon feedstocks containing high metals concentration at reaction conditions of 780-850°F tempera-ture and 1000-3000 psig hydrogen partial pressure. Use of such synthetic catalyst results in improved reactor fluidization opera-tions and low catalyst loss by attrition and carryover of fines from the reactor, and achieves improved results of 60-70 W % hydro-demetallization and 50-70 V % hydroconcersion of the 975°F+
fraction of the feed material to lower boiling hydrocarbon pro-ducts in a single stage operation.

Description

12177S6 ~-1326 DEMETALLIZATION CATALYST AND PROCESS FOR
METALS-CONTAINING HYDROCARBON FEEDSTOCKS

BACKGROUND OF INVENTION

: . , This invention pertains to an improved synthetic demetal- l ¦
lization catalyst material containing substantially porous alumi~
num oxide promoted with 0.5-10 W ~ active metal and to a process using the catalyst for demetallization and hydroconver-sion of metals-containing hydrocarbon feedstocks to produce lower boiling hydrocarbon products.
Bauxite is a naturally-occurring low-cost aluminum oxide material which when promoted with certain metal oxides is rela-tively effective as a catalyst in upgrading heavy metals-containing petroleum feedstocks in an ebullated-bed reactor, provided that the~
catalyst has suitable fluidization patterns in the reactor. The metal compounds need to be substantially removed from such petro-leum crudes or residua fractions to provide suitable feed materials for further processing such as catalytic cracking and/or desulfur- - ¦
ization. For example, U.S. Patents 3,901,792 and 3,965,665 to Wolk, et al, disclose a two-stage catalytic reaction process for demetallization and conversion of high-metals content petroleum residua, in which the first stage contains a promoted bauxite con-tact material which has a primary purpose of removing the vanadium , and nickel compounds from the hydrocarbon feedstock materials. The treatment of the feedstock in the first stage reactor was found to improve the operation of the second stage reactor significantly, and resulted in reduced processing costs for the hydrodesulfuriza-tion operation in the second stage reactor.

12~7756 In a co-pending patent application, a method is disclosed ~or effectively pre-treating the activated promoted bauxite material to achieve more satisfactory operations in an ebullated bed demetallization and hydroconversion process. However, the naturally-occurring bauxite material usually has substantial variations in its chemical composition and in particle size distribution, because these properties are dependent on the geo-graphical location of the mines and formations from which the bauxite is obtained.
Because of these problems with the available naturally-occurring promoted activated bauxite demetallization catalysts and the substantial expense of available combination catalysts when used for demetallization operations, a need exists for further improve~
ments in such demetallization catalysts. A synthetic spherical-shaped demetallization catalyst has been developed for use in ebullated-bed demetallization processes to provide effective and ~, economical processing of high-metals containing residua, such as those from California, Mexican, and Venezuelan petroleum crudes.
This low-cost synthetic catalyst has strong attrition resistance characteristics and provides for effective demetallization opera-tions and provides an alternative to promoted activated bauxite ~catalyst for demetallization of such high-metals content feedstocks.

. .
SUMMARY OF INVENTION o This invention provides a synthetic catalyst material which is particularly useful for demetallization of metals-contain-ing petroleum residua feedstocks. The catalyst comprises particles of substantially aluminum oxide promoted with metal oxides selected from the group consisting of chromium, iron, molybdenum, titanium, and tungsten and having a total metals content of about 1` lZ~7756 0.5-lO W ~, said catalyst having a total pore volume of abaut 0.350 to about 0.500 cc/gm, said catalyst particles within the 3% and 97% percentiles of all particles having an equivalent diameter ratio of larger to smaller particles with~ a range of about 1.~ to 2Ø ~ore specifically, the narrow particle I differential size range is such that the ratio of particle equivalent diameter (based on volume/surface area ratio or the particles) at 97 W % under size to ¦ that at 3 W % under size does not excee~ about 2.0, and preferably is within a ratio range of 1.2-2Ø Also, the catalyst materia~ preferably contains I about 0.6-3.0 W % rnolybdenum promoter, has a surface area of 150-300 square Il meters/gm, and the catalyst particles are preferably within a naminal size jl range o, 12-18 mesh (~.~. Sieve Series). me catalyst particles are preferably , substantially spherical shaped for providing increased structural and crush strength and the uniformity of particle shape and size provide good fluidiza-tion characteristics.
The demetallization catalyst of this invention is particularly advantag-eous compared to catalysts previously used for demetallization operations on ¦ high metals-containing hydrocarbon feedstocks such as petroleum residua. L`abt ~1 oratory tests have demonstrated that this catalyst can typically remove 40-65 ¦I W % of the feed metals, and achieve 50-60 V % conversion of 975F+ material in a one-stage, catalytic single pass operation.
The present invention provides a process for hydrodemetallization and i hydroconversion of hydrocarbon feedstocks containing at least about 200 ppm ¦ total metals, which process uses the synthetic particulate catalyst material ¦~ containing substantially pronoted aluminum oxide as described above. me pro-cess ccmprises introducing a metals-containing hydrocarbon feedstock together with hydrogen-rich gas into an ebullated bed catalytic reaction zone contain- !
, ing particulate aluminum oxide catalyst prcmoted with metal oxides selected fram the group consisting of chramium, iron, molybdenum, titanium and tungsten for hydrodemetallization reactions, said catalyst having a total metals content ,l of about 0.5-10 W % and a total pore volume of 0.350-0.500 cc/gm, said catalyst~

.! particles within the 3-37 percentile of all particles having an equivalent within the 3-97 percentile of all particles having an equivalent diameter ,' ratio of larger to smaller particles not e~ceedin~ about 2.0; maintaining said reaction zone at 780-850F temperature and 1000-3000 psig hydrogen partial I pressure conditions, and catalytically hydrcd~l~tallizillg an~ hydl^ocon~rerl- ing the ,eedstock to produce `nydrocarbon qases and loweî boiling _3_ 12~775~

hydrocarbon fractions; withdrawin~ said hydrocarbon gas and liquid fractions from the reaction zone, and separating the hydrocarbon fractions to produce lower boiling hydrocarbon liquid productsr This demetallization and hydroconversion process for metals-containing petroleum feedstocks and for which an attrition-`resistant low cost catalyst material is needed advantageouslyuses this newly developed catalyst. The catalyst provides for ,' ;improved stable and sustained ebullated bed demetallization opera~ !
tions on high metals-containing feedstocks so as to achieve 60-80 W % removal of nickel and vanadium combined along with 50-70 V % conversion of the 975F+ fraction to produce lower boil- ', ing hydrocarbon products in a single stage process. ' This synthetic catalyst can be advantageously used in either a single stage ebullated bed demetallization process or in the first stage ebullated bed reactor of a two-stage demetalliza- ~
tion and desulfurization process. The catalyst is preferably used .
in the first stage of a two-stage hydrodemetallization, hydro-desulfurization and hydroconversion process.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a graph showing comparative fluidization characteristics of the synthetic spherical catalyst material in an ebullated bed reactor.
FIG. 2 is a schematic diagram showing a typical process for catalytic hydro~emetallizationof hydrocarbon feedstocks in which the synthetic catalyst is advantageously used according to the inven-tion.

12~7756 DESCRIPTION OF INVENTION

According to the present invention, the newly-developed synthetic demetallization catalyst has properties which are selected to be particularly advantageous for demetallization opera-~tions on petroleum feedstocks containing high concentrations of ;metals compounds. Important characteristics of the catalyst in- ' c~ude: i . (a) good removal of vanadium and nickel compounds from processed hydrocarbon feedstocks;
~b) generally spherical shape particles to provide improved crush strength and attrition resistance;
(c) good fluidization patterns in ebullated bed reactor;
(d) low catalyst cOsts.
Properties of the catalyst material are provided in the ~.
following Table I.

TABLE I

Chemical and Physical Properties - Aluminum Oxide, W ~ ~9o ~olybdenum, W % 0.5-3.0 Compacted Bulk Density, gm/cc 0.8-1.0 Surface Area, M /gm 100-300 Pore Volume, cc/gm 0.35-0.50 (Determined by Hg Penetra-tion Method, 60,000 psi) Pore Size Distribution cc/gm 30 A Diameter 0.30-0.50 250 A Diameter 0.19-0.25 500 A Diameter 0.17-0.23 1500 A Diameter 0.15-0.20 4000 A Diameter 0.02-0.15 ~Z177~;

TABLE I (Cont'd.) Particle Size and Distribution Nominal Paxticle Size (U.S. Sieve Series) 12 mesh x 18 mesh Median Particle Size (50 W %) 1.27 + 0.13 mm 97 W % (minimum) of catalyst particles ~ 12 mesh (1.67 mm) 3 W ~ (maximum of catalyst , particles ~ 18 mesh (l mm) Particle diameter ratio for , 12 mesh/18 mesh particles 1.68 .. ;
Because the new synthetic demetallization catalyst of the pre-sent invention is a manufactured product instead of a naturally-occurring bauxite material activated and prcmoted with metal oxides, undesired , variations in the catalyst properties and particle size distribu-tion are advantageously minimized. The pore volume is maintained at least about 0.35 cc/gm and is preferably about 0.40-0.50 cc/gm, which is appreciably larger than for the activated bauxite material~
and particularly has a greater percentage of the pores in diameters, larger than about lO00 A than for activated bauxite. In addition, the synthetic demetallization catalyst material has higher attri-~ ~tion resistance and other advantages compared to the previously used promoted bauxite material, as listed below:
. .
. .

Promoted Activated Synthetic Bauxite Catalyst Catalyst Particle Size Distribution Variable Within Definitive With-Wide Range, Can in Narrcw Range screen for desired narrow particle size ranges.
Particle Shape Irregular, with Spherical sharp corners Attrition Loss (~30 mesh)* 10-15 W % for 0.1-0.4 W ~ for 20 x 30l~esh Size 12 x l~esh Size *Based on 7 hour attrition test in rotating drum.

`' ~Z~7756 ll . l ,` . I

!l 3ecause of the substantially spherical shape of the catalyst particles, they are appreciably stronger and exhibit significantly less attrition than do the naturally-occurring ~,lbauxite catalyst particles. In comparison with pre~reated bauxite¦
Ijcatalyst particles, it is noted tha' the attrition for the syn-¦i thetic catalyst material is less tran about 4% of that for the Ibauxite. Furthermore, the cost of the new synthetic catalyst is ¦,appreciably less than for other known demetallization catalysts.
¦~ The catalyst particles of the present invention may be jlformed of known substrate materials such as a porous alumina.
¦¦Although such alumina should be substantially pure, it may con- l ¦Itain minor amounts of other metal oxides that are inert under the ¦
¦Iconditions of use. Other support materials such as silica-alumina ¦land catalytically active clays may also be used.
¦l A variety of procedures can be employed for preparing the alumina support particles. In general, the smaller pores are associated with alumina base materials. The larger pores can be Il formed by known techni~ues ~7hich cculd employ pore growth pro- !
limoters. Catalyst pore growth promotion can be accomplished by ¦Iheating the material in the presence of a oas or ~etal compound, stea~ing at elevated temperatures and treating with hydrogen at ¦~elevated temperatures. In another procedure, the larger pores czn, j'be produced during preparation ~f the base material by use of a ~strong mineral or organic acid for leaching.
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A number of different catalytically active metals can be deposited on the surface of the alumina substrate material of the present catalyst. One preferred catalyst material uses molybdenum in the form of Mo03. When molybdenum is used alone as a promoter material, it provides good demetallization performance. Other ;
known metal oxides may be employed as promoters for the active metal, for example, oxides of cobalt and nickel can be beneficial-ly employed in c~mbination with molybdenum for superior demetalli-~
zation. A preferred catalyst c~ntains between about 0.5 and S
10 W ~ molybdenum in the form of MoO3.

-A ~eneral disclosure of tèchniques for catalyst formation is found in an article by Higginson, G.W., Chemical Engineering, Sept. 30, 1974. A more detailed disclosure of suitable catalyst forming techniques is found in Long ~t al ~.S. Patent ~o.3,989,645' Also, additional general information regarding preparation of~
catalysts may be found in "Heterogeneous Catalysis In Practice"
by C.M. Satterfield, published by McGraw-Hill Co., 1580, Chap. 4 p. 68-97.
The particle size of the catalyst support substrate should be small enough to provide the desired contact area and be readily ebullated in a reactor bed,as in the'H-Oil'process.
Laboratory fluidization tests comparison results per FIG. 2 showed that the bed expansion characteristics of the new synthetic demetallization catalyst are similar to the conventional catalysts widely used in the'H-Oil'process. This new spherical-shaped synthetic catalyst has excellent fluid dynamics qualities and provides smooth and uniform fluidization patterns in the catalyst bed, and minimum catalyst carryo~er fr~m the ebullated bed reactor. The synthetic spherical catalyst of the present in-* Trademark ~2~756 vention is a preferred al~tive to promoted bauxite catalystfor demetallization o~erations on metals-containing feedstocks.
This new spherical-shaped catalyst material is advantageous-ly used in a demetallization process for a high metals-containing hydrocarbon feedstocks containing at least about 200 ppm total ; metals Gnd preferably containing 400-1500 ppm total metals. As generally shown in FIG. 2, the catalyst is introduced into re-actor 20 to provide ebullated catalyst bed 22 therein. A petro-leum residuum feedstock containing metal compounds including vana-dium and nickel is preheated along with a hydrogen~rich gas stream i and introduced into the lower end of reactor 20. If desired, reactor 20 can be the first stage of a two-stage process for demetallization of the feed in a first stage reactor, followed by , hydrode ~ furization reactions in a second stage reactor using a high activity desulfurization catalyst. ' The metals-containing petroleum feedstock at 10, containing at least about 200 ppm total metals, such as Cold Lake and Lloydminster bottoms from Canada or Bachaquero and Orinoco residua from Venezuela, is pressurized at 12 and passed through preheater 14 for heating to at least about 500F. The heated feedstream at 15 is introduced into upflow ebullated bed catalytic reactor 20.
Heated hydrogen is provided at 16, and is also introduced into reactor 20. This reactor is typical of that described in U.S.
Patent No. ~e.2~,77b, wherein a liquid phase reaction is accomp-lished in the presence of a reactant gas and a particulate catalyst such that the catalyst bed 22 is expanded. The reactor contains a flow distributor and catalyst support plate 21, so that the feed liquid and gas passing upwardly through the reactor 20 will expand the catalyst bed by at least about 10% over its settled height, and place the catalyst in random motion in the liquid.

_g_ ~21~i6 The synthetic catalyst particles in ebullated bed ~2 will ha~e a relatively narrow s~ze range fox uniform bed expansion under controlled liquid and gas flow conditions. While the usefuL
catalyst size range is between 12 and 20 mesh (U.S. Sieve Series) with an upflow liquid velocity between about 1.5 and 10 cubic feet, per minute per square foot of reactor cross-section area~ the `~
catalyst size is preferably particles of 12-18 mesh size. In the reactor, the density of the catalyst particles, the liquid upward flow rate, and the lifting effect of the upflowing hydrogen gas are important factors in the expansion of the catalyst bed. By control of the catalyst particle size and density and the liquid and gas upflowing velocities and taking into account the viscosit~
of the liquid at the operating conditions, the catalyst bed 22 is ', expanded to have an upper level of interface in the liquid as indicated at 22a. The catalyst bed expansion should be at least about 10% and is seldom more than about 80% of the bed settled-or static height.
The proper ebullation of the catalyst in bed 22 in reactor 20 is greatly facilitated by use of a proper size catalyst. The -synthetic catalyst used is added daily directly into the reactor 20 through suitable inlet connection means 25 at a rate between aboùt 0.3 and l.0 lbs catalyst/barrel feed, and used catalyst is withdrawn daily through suitable draw-off means 26.
Recycle of reactor liquid from above the solids interface 22a to below the flow distributor 21 is usually desirable to establish a sufficient upflow liquid velocity to maintain the catalyst in random motion in the liquid and to facilitate com-pleteness of the hydrogenation reactions. Such liquid recycle is preferably accomplished by the use of a central downcomer conduit 18 which extends to the suction side of a recycle pump 19 located below the flow distributor 21, to assure a positive and controlled upward movement of the liquid through the catalyst bed ~2.

~z~7~5~

Operability of the ebullated catalyst bed reactor system to assure good contact and uniform (iso-thermal) temperature 3 therein depends not only on the random ~otion of the catalyst in the liquid environment resulting from the buoyant effect of the upflowing liquid and gas, but also requires the proper reaction conditions. With improper reaction conditions,insufficient de- i metallization of the feedstock is achieved. For the ~etroleum 3 feedstocks useful in this invention, i.e., those having total metals at least about 200 ppm, operating conditions needed in the reactor 20 are within ranges of 780-850F temperature, 1000-3000 psig, hydrogen partial pressure, and space velocity of 0.20-1.50 Vf/hr/Vr ~volume feed per hour per volume of reactor). Preferred reaction conditions are 790-830F temperature, 1500-2800 psig, hydrogen partial pressure, and space velocity of 0.25-1.20 Vf/hr/Vr. The feedstock hydroconversion achieved is about 5U-70 % for the first stage of once through type operations.
In an ebullatéd bed reactor system, a vapor space 23 existsi above the liquid level 23a and an overhead stream containing both liquid and gas portions is withdrawn at 27, and passed to hot phase separator 28. The resulting gaseous portion 29 is princi-pally hydrogen, which is cooled at heat exchanger 30, and may be recovered in gas purification step 32. The recovered hydrogen at 33 is warmed at heat exchanger 30 and recycled ~y compressor 34 through conduit 35, reheated at heater 36, and is passed into the bottom of reactor 20 along with make-up hydrogen at 35a as needed.
From phase separator 28, liquid portion stream 38 is with-drawn, pressure-reduced at 39 to pressure below about 200 psig, and passed to fractionation step 40. A condensed vapor stream also is withdrawn at 37 from gas purification step 32 and also passed to fractionation step 40, from which is withdrawn a low pressure gas stream 41. Thi~ vapor stream is phase separated at ~.Z~7~7~;6 42 to provide low pressure gas product 43 and liquid stream 44 to provide reflux liquid to fractionator 40 and naphtha product stream 45. A middle boiling range distillate liquid product stream is withdrawn at 46, and a heavy hydrocarbon liquid stream ~s withdra~n at 48. .
From fractionator 40, the heavy oil stream 48 which usualiy~
,. has normal ~oiling temperature range of 650F+, is withdrawn, i reheated in heater 49 and passed to vacuum distillation step 50.
A vacuum gas oil stream is withdrawn at 52, and vacuum bottoms stream is withdrawn at 54. If desired for two-stage e~ullated bed;
reactor operations, a portion 55 of the vacuum bottoms material usually boiling above about 975F can be recycled to the reactor system for further hydroconversion. A heavy vacuum bottcms material is withdrawn at 56.
, This invention will be further described by reference to the following examples, which should not be construed as limiting , in scope.

. EXAMPLE 1 The fluid dynamics characteristics of the spherical shaped : 12-18 mesh size LX-102 catalyst were determined in a laboratory catàlyst ebullation test conducted in a 1 inch diameter glass tube;
`apparatus using nitrogen gas and liquid heptane to simulate typical e~ ated bed reaction operations. Specific characteristics of the synthetic catalyst used are pravided ~ ~able 2. For catalyst bed expansions of 20-60%
ab~ve its settled level using upward gas velocities of 0.04-0.16 fps and liquid velocities of 0.10-0.15 fps, the catalyst bed interface bet~ catalyst and liquid was stable and the bed expansion correlated well with ex-pected values. Comparative results of catalyst bed expansion vs.
upflowing liquid superficial velocity are shown in FIG.2.

lZ17756 INSPECTION OF FRESH SYNTHETIC CATALYST
Gatalyst Designation LX-102 Nominal Size (U.S. Sieve Series) 12-18 Mesh Molybdenum (Nominal), W % 1 6 Physical Properties Surface Area, M /gm 163 Pore Volume, cc/gm ( 30 A) 0.442 ; Compacted Bulk Density, gm/cc 0.815 Attrition Loss, W ~ - 30 Mesh 1.6 Pore Size Distribution (Pore Volume) 30 ~ ~iameter, cc/gm 0.442 250 R Diameter, cc/gm 0.234 500 R Diameter, cc/gm 0.214 1500 A Diameter, cc/gm 0.194 4000 R Diameter, cc/gm 0.141 3 It was observed that the catalyst e~bited smcoth operation in the re-~actor with well defined upper le~el for the catalyst bed over a wide range of percentage bed expansion.
E~1E 2 To verify the catalyst attrition and carryover rate per~
; formance for the spherical catalyst under actual reaction condi-tions at typical elevated temperatures and pressures, a sustained run of over 5 days duration was conducted using 12-18 mesh size LX-102 catalyst in an 0.6 inch diameter single stage ebullated bed reactor at about 810-815F temperature and 2100-2400 psig hydrogen partial pressure conditions, using a typical petroleum residuum ; feedstock containing high metals and sulfur. Characteristics of the catalyst used are shown in Table 2 and characteristics of the feedstock used are shown in Table 3.

~2~7~S~
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FEEDSTOCK INSPECTIONS

Feedstock Bachaquero Vacuum Bottoms Gravity, API 5.8- 6.3 Sulfur, W % 3.36- 3.71 Carbon, W % 85.2-85.90 Hydrogen, W % 10.3-10.35 RCR, W % 16.3-19.51 Nitrogen, ppm 5900-6200 Vanadium, ppm 650- 795 Nickel, ppm 87- 89 IBP-975 ~raction Volume, % 18-20 Gravity, API 14.0-14.7 Sulfur, W % 2.6- 2.74 975F+ Frac~ion !
Volume, % 80-81.6 Gravity, API 3.7- 4.7 Sulfur, W % 3.6- 3.84 Vanadium, ppm 780-1000 Nickel, ppm 100- 130 Typical operating results obtained from ebullated catalyst bed hydrodemetallization operations in the one-stage, single pass laboratory size catalytic reactor are summarized in Table 4 below:

.
Catalyst Designation LX-102 Feedstock Bachaquero Vacuum Bottoms Reactor Conditions.
Temperature, F 810-815 Hydrogen Partial Pressure, psig 2250 Space Velocity, Vf/hr/Vr 0.6 Operatinq Results:
975F+Conversion, V % 57_59 RCR Conversion, W ~ 33.6 Vanadium Removal, W % 65 Nickel Removal~ W % 45 Sulfur Removal~ W ~ 51 ~1 ~z~77s6 Laboratory tests were conducted on a petroleum residua ¦¦material in a small scale reactor having 0.62 inch inside dia-¦lmeter. Results showed that this new catalyst was ef~ective in re-moving metal and sulfur compounds from the feedstock and in con-Iverting the 975F+ material to lower boiling fractions.
Although this invention has been described broadly and with reference to certain preferred embodiments thereof, it will be understood that modifications and variations of the process can be made and that some steps can be used without others all within the spirit and scope of the invention, which is defined by the follow-~ng laims.

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Claims

WE CLAIM:

1. A demetallization catalyst material useful for de-metallization metals-containing petroleum feedstocks, said cata-lyst comprising particles of substantially aluminum oxide pro-moted with metal oxides selected from the group consisting of chromium, iron, molybdenum, titanium, and tungsten, said catalyst having a total metals content of about 0.5-10 W %, and a total pore volume of about 0.350 to about 0.500, cc/gm, said catalyst particles within the 3-97 percentiles of all particles having an equivalent diameter ratio of larger to smaller particles not ex-ceeding about 2Ø

2. A catalyst material according to Claim 1, wherein said catalyst contains 0.6-3.0 W % molybdenum promoter.

3. A catalyst material according to Claim 1, wherein said catalyst has a surface area of 100-300 square meters/gm.

4. A catalyst material according to Claim 1, wherein the catalyst equivalent diameter ratio of larger to smaller particles is within a range of about 1.2 and 2Ø

5. A catalyst material according to Claim 1, wherein said catalyst particles are within a nominal size range of 12-18 mesh (U.S. Sieve Series).

6. A catalyst material according to Claim 1, wherein said catalyst particles are spherical in shape.

7. A catalyst material useful for demetallizing petroleum feedstocks, said catalyst comprising particles of substantially aluminum oxide promoted with 0.6-3.0 W % molybdenum, said catalyst having a surface area of 100-300 square meters/gm and a total pore volume of about 0.350 to about 0.500 cc/gm, said catalyst particles within the 3-97 percentile of all particles having an equivalent diameter ratio of larger to smaller particles within a range of about 1.2 to 2.0 and a nominal particle size range of 12-18 mesh (U.S. Sieve Series).

?

8. A process for hydrodemetallization and hydroconversion of hydrocarbon feedstocks containing at least about 200 ppm total metals using a synthetic particulate catalyst material containing substantially promoted aluminum oxide, said process comprising:
(a) introducing a metals-containing hydrocarbon feedstock together with hydrogen-rich gas into an ebullated bed catalytic reaction zone, said zone containing parti-culate aluminum oxide catalyst promoted with metal oxides selected from the group consisting of chrominum, iron, molybdenum, titanium, and tungsten for hydro-demetallization reactions, said catalyst having a tot metals content of 0.5-10 W % and total pore volume of about 0.380-0.500 cc/gm, said catalyst particles with-in the 3-97 percentile of all particles having an equivalent diameter ratio of larger to smaller parti-cles not exceeding about 2.0;
(b) maintaining said reaction zone at 780-850°F tempera-ture and 1000-3000 psig hydrogen partial pressure conditions, and catalytically hydrodemetallizing and hydroconverting the feedstock to produce hydrocarbon gas and lower boiling hydrocarbon fractions; and (c) withdrawing said hydrocarbon gas and liquid fractions from the reaction zone, and separating the fractions to produce lower boiling hydrocarbon liquid products.

9. A hydrocarbon hydrodemetallization process according to Claim 8, wherein the catalyst particles are substantially aluminum oxide promoted with 0.5-3 W % molybdenum.

10. A hydrocarbon hydrodemetallization process according to Claim 8, wherein the catalyst particles within the 3-97 percentile of all particles have effective diameter ratio of larger to smaller particles within a range of 1.2-2Ø

11. A hydrocarbon hydrodemetallization process according to Claim 8, wherein the catalyst particles have size range of about 12-18 mesh (U.S. Sieve Series).

12. A hydrocarbon hydrodemetallization process according to Claim 8, wherein the hydrodemetallization reactions occur at 780-840°F temperature, 1200-2800 psig hydrogen partial pressure, and 0.2-1.5 Vf/hr/Vf space velocity to achieve 60-70 W % removal of metals and 50-70 V % hydroconversion of the feedstock to lower boiling hydrocarbon products.

13. A hydrocarbon hydrodemetallization process according to Claim 8, wherein the feedstock has total metals content of 200-2000 ppm by weight.

14. A process for hydrodemetallization and hydroconversion of hydrocarbon feedstocks containing at least about 200 ppm total metals using a synthetic particulate catalyst material consisting of substantially promoted aluminum oxide, said process comprising:
(a) introducing a hydrocarbon feedstock containing 200-2000 ppm total metals together with hydrogen-rich gas into an ebullated bed catalytic reaction zone con-taining particulate aluminum oxide catalyst promoted with 0.5-3 W % molybdenum for hydrodemetallization reactions on the feed, said catalyst particles within the 3-97 percentiles of all particles have an effective diameter ratio of larger to smaller particles within a range of about 1.2-2.0;
(b) maintaining said reaction zone at 780-840°F tempera-ture and 1200-2800 psig hydrogen partial pressure conditions, and catalytically hydrodemetallizing and hydroconverting the feedstock to produce hydrocarbon gas and lower boiling hydrocarbon fractions; and (c) withdrawing said hydrocarbon gas and liquid fractions from the reactionzone, and separating the fractions to produce lower boiling hydrocarbon liquid products.