CA2362466C

CA2362466C - Preparation of a hydrotreating catalyst

Info

Publication number: CA2362466C
Application number: CA002362466A
Authority: CA
Inventors: Alexei Grigorievich Gabrielov; Opinder Kishan Bhan
Original assignee: Shell Internationale Research Maatschappij BV
Current assignee: Shell Internationale Research Maatschappij BV
Priority date: 1999-02-15
Filing date: 2000-02-08
Publication date: 2007-10-30
Anticipated expiration: 2020-02-08
Also published as: DK1154855T3; AU754251B2; DE60012887D1; JP2002536166A; BR0008224A; US6290841B1; JP5264029B2; CN1339986A; ID30051A; KR100621251B1; CN1134303C; US6218333B1; EP1154855A1; AU3592500A; ZA200106590B; DE60012887T2; KR20010101813A; EP1154855B1; CA2362466A1; WO2000047321A1

Abstract

There is provided a process for preparing a catalyst wherein the volatile content of an impregnated support is reduced in one or more steps, wherein at least one volatile content reduction step is performed in the presence of a sulfur containing compound.

Description

DESCRIPTION
PREPARATION OF A HYDROTREATING CATALYST

Technical Field This invention relates to catalytic hydrotreatment of hydrocarbonaceous feedstocks.

Background Art Petroleum feedstocks are characterized by relatively high levels of contaminants, including sulfur, nitrogen, Conradson carbon residue, aromatic compounds and metals such as nickel, vanadium and iron. During catalytic hydroprocessing heterogeneous catalysts are contacted with a feedstock in the presence of hydrogen under conditions of elevated temperature and pressure to reduce the concentration of the contaminants in feedstocks. The hydrotreating process promotes reactions such as hydrodesulfurization (HDS), hydrodenitrogenation (HDN), Conradson carbon removal, hydrodemetallation (HDM) and aromatics saturation, accompanied by a boiling shift to lower boiling temperature products. As the sulfur and nitrogen components are converted into hydrogen sulfide and ammonia, metals are deposited onto the catalyst. The results include producing ecologically clean hydrocarbon products such as fuels and protecting other downstream refining catalysts from deactivation.

Processes for removing heteroatoms from feedstocks are known in the art as are catalysts for such removal. Typically, hydroprocessing catalysts contain Group VI and/or Group VIII

active metal components supported on a porous refractory oxide such as alumina, alumina-silica, silica, zeolites, titania, zirconia, boria, magnesia and their combinations. Such catalysts are often prepared by combining the active metals with the support. The supports, containing metal components, are typically dried and calcined at the temperatures ranging from about 3700 C to 600 C to eliminate any solvent and to convert metals to the oxide form. The calcined metal oxide catalysts are then typically activated by contacting with a sulfur containing compound such as hydrogen sulfide, organo sulfur compounds or elemental sulfur to convert metal oxides into catalytically active metal sulfides.

An important and continuing aim in the refining catalyst art is to develop new high performance hydroprocessing catalysts in order to obtain high quality oil products and improve refinery economics. Variations in compositional characteristics or methods of preparation of hydroprocessing catalysts have been attempted to reach these objectives.

It is known in the art that uncalcined catalysts usually provide higher dispersion of active components thereby improving hydrotreating activities. It is essential for the uncalcined catalysts that the active components, such as Group VI and/or Group VIII metal compounds, and promoters such as phosphorous, are not converted into oxide form during a high temperature step. That is, the active components are maintained without chemical decomposition until sulfurizing.
For example, US 5,198,100, US 5,336,654 and US 5,338,717 disclose a method for preparing a hydrotreating catalyst by impregnating a refractory support with a salt of Group VI

metals and with the Group VIII metal heteropolyacids. The catalyst is not calcined or subjected to high temperatures, thereby retaining the heteropolyacids in the original form on the support; however, complete moisture removal from the catalyst during a high vacuum drying step is required before the catalyst is sulfurized.

In general, as the activity of an uncalcined catalyst is increased, the hydrotreating conditions requi-red to produce a given oil product become more mild. Milder conditions require less capital investment to achieve the desired product specifications, such as allowed levels of sulphur, nitrogen, Conradson carbon residue, metals and aromatics, and the catalyst's life is extended due to lower coke formation and other factors.
It has surprisingly been found that preparation of an uncalcined catalyst using a combined volatile content reduction-sulfurizing step allows for the catalyst to be prepared at lower temperatures, in less steps and without calcinations, resulting in a catalyst with excellent hydrotreating actiLvity and stability.
Disclosure of the Invention The process of the invention allows one to prepare a ls catalyst while using a combined volatile content reduction-sulfurizing step. The process comprises:
providing a porous support;
combining said support with one or more catalytically active metals by impregnation, co-mulling or co-precipitation, thereby forming a catalyst precursor having a volatile content greater than 0.5 percent; and reducing the volatile content of the catalyst precursor in one or more steps, wherein at least one volatile content reduction step is performed in the presence of at least one sulphur containing compound;
wherein said catalyst precursor does not reach a calcining temperature in the range of from 400 C to 600 C
prior to said at least one combined volatile content reduction-sulfurizing step.

There is also provided a process for preparing a catalyst suitable for hydrotreatment of a hydrocarbonaceous feedstock, said process comprising:
combining a porous support with one or more catalytically reactive metals selected from Group VI and Group VIII of the Periodic Table, thereby forming a catalyst precursor having a volatile content; and reducing the volatile content of the catalyst precursor in one or more steps, wherein at least one volatile content reduction step is performed in the presence of at least one sulphur containing compound;
wherein t:he catalyst precursor does not reach calcining temperatures prior to said at least one combined volatile content reduction-sulfurizing step.
Further, t;here is provided a process for catalytic hydrotreatment of a heteroatom-contaminated hydro-carbonaceous feedstock, said process comprising contacting said feedstock at elevated temperature and elevated pressure in the presence of hydrogen with one or more catalysts beds; wherein at least one catalyst bed contains a catalyst prepared by the process comprising combining a porous support with one or more catalytically active metals selected from Group VI and Group VIII of the Periodic Table, by impregnation, co-mulling or co-precipitation, thereby forming a catalyst precursor having a volatile content greater than 0.5 percent, and reducing the volatile content of the catalyst precursor in one or more steps, wherein at least one volatile content reduction step is performed in the presence of one or more sulphur containing compounds; and wherein said catalyst precursor does not reach a temperature in the range of from 400 C to 600 C
prior to said at least one combined volatile content reduction-sulfurizing step.
There is further provided a catalyst obtained by the process comprising combining a porous support with one or more catalytically active metals, by impregnation, co-mulling or co-precipitation, thereby forming a catalyst precursor having a volatile content greater than 0.5 percent; and reducing the volatile content of the catalyst precursor in one or more steps, wherein at least one volatile content reduction step is performed in the presence of at least one sulphur containing compound;
ls wherein said catalyst precursor does not reach a temperature in the range of from 400 C to 600 C prior to said at least one combined volatile content reduction-sulfurizing step.
Brief Description of the Drawings FIG. 1 shows the weighted average bed temperature (WABT) required for 88% HDS activity of a catalyst made by the process of the invention versus a catalyst made by a conventional process.
FIG. 2 shows the WABT required for 88% HDS activity of a catalyst made by the process of the invention versus a commercial catalyst.

FIG. 3 shows the temperature required for 30% total nitrogen removal :by a catalyst made by the process of the invention versus a. commercial catalyst.
FIG. 4 shows the temperature required for 30% basic s nitrogen removal :by a catalyst made by the process of the invention versus a. commercial catalyst.
Detailed Description of the Invention In conventional preparation of sulfurized catalysts, an inorganic support is dried, calcined and combined with one or more catalytically active metals to form a catalyst precursor. The precursor is then optionally aged and moisture is driven from the pores of the precursor by drying. The catalyst precursor is then calcined at high temperatures in direct contact with hot gas to remove residual moisture and to convert metal precursor into oxide form. "Calcination temperatures" as used herein shall mean the calcination temperatures of 400 C to 600 C, which are typically used in the art. When calcination is completed, the precursor is sulfurized to form a catalyst.
Under the process of the present invention, a catalyst is prepared by combination of a porous carrier with one or more catalytically active metals to form a catalyst 5a precursor having avolatile content. The volatile content of the catalyst precursor is then reduced in one or more steps.
Volatile content reduction may take place, for example by treating the precursor in air at temperatures below calcination temperatures, or simply by dehydrating at ambient conditions.
At least one of the volatile content reduction steps is conducted in the presence of one or more sulfur containing compounds and, prior to this combined volatile content reduction-sulfurizing step, the catalyst precursor is not allowed to reach calcination temperatures.

The combined volatile content reduction-sulfurizing step(s) may be conducted in-situ or ex-situ. After volatile content and sulfurizing is completed, the catalyst may be activated further using a liquid phase activation at elevated temperatures. For example, if ex-situ pre-sulfurizing is employed, the catalyst may be contacted with a lighter feedstock to produce a supported metal sulfide catalyst. A
variety of other sulfurizing techniques may be used to produce a sulfurized catalyst and reduce solvents from the catalyst pores at the same time. No conventional high temperature calcining of the catalyst or catalyst precursor is necessary.
The catalyst undergoes a weight loss during processing as volatile compounds such as solvents and/or organic and inorganic ligands (functional coordinating groups having one or more pairs of electrons to form coordination bonds with metals) are removed. As used herein, "volatile content" shall mean weight loss as calculated following exposure of a sample to air at 482 C for two hours:

(sample weight before treatment) - (sample weight after treatment) x100 sample weight before treatment As used herein, "catalystprecursor" means a carrier which has been combined with one or more catalytically active metals which have not yet been activated.

"Sulfurizing" when used herein means contacting the catalyst precursor with one or more sulfur containing compounds. A "sulfurized catalyst" is a catalyst in which active metal components are converted, at least in part, to metal sulfides.

In the process of the invention, the catalyst precursor, that is a carrier with deposited active metals, and optionally promoters, is not calcined. At least one volatile content reduction step is conducted in the presence of one or more sulfur containing compounds. The volatile content of the catalyst precursor is typically no less than about 0.5%, preferably from 2% to 25%, more preferably from 3 to 10%, most preferably from 6 to 10% before the catalyst precursor is exposed to the combined volatile content reduction-sulfurizing step. No calcination of the catalyst precursor is necessary or performed and, in fact, allowing the catalyst precursor to reach calcination temperatures is detrimental to the results seen when the process of the invention is used. The combined volatile content reduction-sulfurizing step may be done in-situ (in the reactor where the catalyst will be used) or ex-situ.
The hydrotreating performance of the resultant catalyst is greatly improved over catalyst made by the conventional method, and the process is simplified by eliminating the high temperature calcination step of conventional processes.

A porous support is typically used to carry the catalytically reactive metal(s). For hydrotreating catalysts, supports are typically alumina, alumina-silica, silica, titania, zirconia, boria, magnesia, zeolites and combinations thereof. Porous carbon-based materials such_ as activated carbon and/or porous graphite can be utilized as well. The preferred supports in this invention are alumina-based and alumina-silica based carriers. Catalytically active metals typically chosen from Groups VI and VIII of the Periodic Table are deposited onto the support. Typically the metals are selected from molybdenum, tungsten, cobalt, nickel, and mixtures thereof. Promoters, such as phosphorous may be used in combination with the catalytically active metals.
Variations in catalyst preparation methods include impregnation, co-mulling and co-precipitation. The preferred method in this invention is impregnation, with the most preferred method being incipient wetness impregnation. The use of aqueous solutions is common; however, organic solvents such as aliphatic and aromatic hydrocarbons, alcohols, ketones, etc., can be also used to deposit soluble active components and promoters onto the carrier. Examples of aqueous solutions include those containing molybdates (such as di- and hepta-molybdates), molybdo- and tungsto-phosphates and silicates, polyoxometallates (such as heteropolyacids and transition metal complexes thereof), various metal chelate complexes, amine complexes, etc. The pH value of the aqueous solutions typically range from 1 to 12. The solution preparation techniques and methods for impregnation are well known in the art.

The catalyst precursor of the present invention may have some of its volatile content reduced in air at temperatures below calcination temperatures, including ambient conditions, or it may be moved directly to the sulfurizing step. Partial volatile content reduction to remove physically adsorbed solvents (remaining from an impregnation step) aids in transporting the catalyst should the volatile content reduction be conducted in-situ. -Without being tied to a particular theory, it is believed that the process of the invention controls the formation of bulky metal oxide phases in the catalyst pores by direct interaction of the catalytic metal with a sulfur containing compound below calcination temperatures, such that thermal agglomeration of the active component does not occur.
As the precursor is sulfurized, sulfur compounds displace the solvent and the sulfur reacts with the metals to form highly dispersed metal sulfides before a substantial amount of bulky metal oxides can form. In the process of the invention the catalyst precursor, containing residual moisture, is exposed to a sulfur containing compounds at temperatures that convert the metal precursors to catalytically active metal sulfides and drive the moisture out of the catalyst pores.

Typical in-situ sulfurization may utilize either gaseous hydrogen sulfide in the presence of hydrogen or liquid-phase sulfurizing agents such as organo sulfur compounds including alkylsulfides and polysulfides, thiols, sulfoxides, etc.

In ex-situ sulfurization, the catalyst is typically supplied to the user (refiner) in the "pre-sulfided" form where the metal oxides are converted at least in part to metal sulfides. Commercial ex-situ sulfurization processes include, for example, the ACTICATO process (CRI International Inc.), described in US 5,468,372 and US 5,688,736, and the SULFICAT
process (Eurecat US Inc.). In the practice of present invention, ex-situ sulfurizing is preferred.

In the present invention the known ex-situ and in-situ processes described are modified by not calcining the catalyst at high temperatures prior to contacting the catalyst with sulfur compounds. At least one of the volatile content reduction steps is conducted in the presence of one or more sulfur containing compounds. Significantly higher activity and stability of the ancalcinod catalyst are achieved as compared with catalysts made by conventional processes of separate drying, calcining and sulfurizing steps. it is believed that higher hydrotreating activity is achieved because of higher dispersion of active components since thermal agglomeration does not occur during catalyst preparation.
The catalyst made by the process of the invention may be used in a process for removing heteroatom and other-contaminants from a hydrocarbonaceous feedstock accompanied by boilizg point reduction. Such a process comprises contacting of catalyst with a feedstock at elevated temperature and elevated pressure in the presence of hydrogen with one or more catalysts beds. Temperatures are typically in the range from about 200 ' C to about 470 C, total pressures are typically in the range of from about 443 kPa (50 psig) to about 24,233 kPa (3500 psig), and liquid hourly space velocities (LI3SV) typically range from 0.05 to 25 h-1.
Examples Catalyst Activity Testing Hydrotreating activities of the catalysts of the following Examples were compared on a volumetric basis using trickle flow micro-reactors. The same catalyst volume, basis compacted bulk density, was used for each set of test conditions. The reactors were operated in an isothermal regime. To ensure appropriate irrigation and plug flow characteristics, the trilobe-shaped extrudated catalyst pellets were diluted with 180-250 micron (80-60 mesh) SiC in the volumetric catalyst-to-dilutant ratio of either 1:1 (Test Conditions 1-3) or 1:2.5 (Test Condition 4), and loaded into the reactor in four aliquots.

r:\legal\b98\sFecs\Ch1287_pct.doc 10 AMENDED SHEET
nicrn v r-..~u .. .-..., .. .. ..
T - r -r,r . rA

rn-Situ Catalyst Sulfurization A gas mixture of 5%- H2S in hydrogen was used for catalyst sulfurizing. The sulfurizing pressure was maintained at about 443 kPa (50 psig) (Test Conditions 1-3) and 1,128 kPa (150 psig) (Test Condition 4). Temperature -ramping during sulfurization was as follows: ambient to 204 C at a rate of 3..5 C/min, holding for 2 hours; heating to 316 C at a rate of 2 C/min, holding for I hour; heating to 3710 C at a rate of 3 C/min, holding for 2 hours; cooling to 204 C and introducing a test feed.

Ex-Situ Catalyst Pre-sulfurizin9 The ex-situ pre-sulfurizing was perforrned using the ACTTCAT process. A sample of catalyst was treated with a stoichiometric amount, based on the metal content of the catalyst, of powdered elemental sulfur plus 1.0 %-w excess, based on the weight of the total catalyst, followed by heating the sulfur-incorporated catalyst in the presence of a liquid olefinic hydrocarbon. The pre-sulfurized catalyst preeursore were activated in-situ using standard liquid phase activation.
Liquid Phase Catalyst Activation The ex-situ pre-sulfurized catalyst precursors were placed into a trickle flow micro-reactor and activated with a diesel feed to convert the sulfur compounds on the pores into metal sulfides. Catalyst activation took place at a unit pressure of 6,307 kPa (900 psig), a hydrogen flow rate of 220 ml/min, and a diesel feed LHSV of 1.5 h'1. The temperature was ramped to 135 C and held for 1 hour; increased at a rate of 24 C/hour to 3710 C and held for 1 hour; and decreased to 204 C and held for two hours followed by test feed introduction.

r:\legal\bga\specs\th1287_pct.doc 11 AMENDED SHEET

Test Condition 1:
Catalyst: 100 cc stacketi bed:
Commercial HDM catalyst - 33.3%
Experimental Catalyst - 66.7%
Pressure: 13,201 kPa (1900 psig) LHSV: 0.33 hr"1 (total system) WABT: 385 C
Gas Rate: 712.4 m' H2/m3 (4,000 scf Hz/bbl) Test Feed: Straight run long (atmospheric) residue:
Sulfur 4.34 $w Nitrogen 0.26 tw Nickel 18.5 ppm Vanadium 62.0 ppm Basic Nitrogen 667 ppm Microcarbon residue 11.4 %w Density at 15 C 0.97 g/l Test Condition 2:
Catalyst: 50 cc single bed Pressure: 6,996 kPa (1000 psig) Lf---SV: 1. 5 hr 1 inTABT : 3 54 C
Gas Rate: 356.2 m' Hz/m' (2,000 scf H,/bbl) Test Feed: Heavy vacuum gas oil Sulfur 1.07 *w Nitrogen 0.29 tw Nickel 0.8 ppm Vanadium 0.6 ppm Basic Nitrogen 930 ppm Microcarbon residue 0.3 %w Density at 15 C 0.92 g/l Test Condition 3:
Catalyst: 25 cc single bed Pressure: 14,580 kPa (2100 psig) LHSV: 0.3 hr'1 WABT: 385 0 C

Gas Rate: 356.2 m' Hz/m3 (2,000 scf Eiz/bbl) Test Feed: Demetallized vacuum residue r:\ieyallbgs\agecs\this8~~oct=rloc 12 AMENDED SHEET

Sulfur 2.15 tw Nitrogen 0.39 $w Nickel 19.0 ppm Vanadium 33.0 ppm Basic Nitrogen 1354 ppm Microcarbon residue 12.0 $w Density at 15' C 0.98 g/l Teat Condition 4:
Catalyst: 20 cc single bed Pressure: 11,478 kPa (1650 psig) LHSV : 2. 2 hr'3 WABT: 343 C and 363 C
Gas Rate: 623.35 m3 H2/m' (3,500 ecf H;/bbl) Test Feed: Straight run gas oil Sulfur 1.80 *w Nitrogen 0.0448 %w Density at 15 C 0.86 g/l Example 1 An alumina extrudate (1.2 mm trilobe) was dried in air at 482 C for two hours. The extrudate had the following physical properties:

Compacted bulk density 0.475 g/cc Water pore volume 0.94 cc/g S.E.T surface area 296 m2/g An impregnation solution was made by dissolving 39.1 g of phosphomolybdic acid (75%, obtained from ACROS) and 9.72 g NiCO3 in 100 g de-ionized water at 60 C. After complete dissolution, 7.02 g of 85% H3PO4 were added. The volume of the solution was adjusted to a value equal to the water pore ztolume of the support. 200 grams of the support were impregnated with the solution and aged for 2 hours. The amount of metals loaded (dry basis) was 8%w Mo, 2$w Ni, and 1tw P.
To remove exceas moisture, the catalyst precursor was air-treated below 850 C for 1 hour and the volatile content was r:\1ega1\bgs',speca\i.h1287_pct.doc 13 AMENDED SHEET

~----_ -----~-reduced to 6%, whereafter the precursor was recovered still containing residual moisture. The precursor was further dehydrated s_multaneously with sulfurizing during an ACTICATm process. NO calcination steps were employed. The resultant catalyst is denoted as Catalyst A.

Catalyst A was placed into a micro-reactor and activated with a diesel feed, followed by testing according to Test Condition 1. The HDS activity of Catalyst A, as w6ighted average bed temperature (WABT) required for 88%- RDS, is shown in Figure 1.

Example 2 - Comparative An alumina extrudate (1.2 nnm trilobe) with the following properties was used to make Catalyst B:

Compacted bulk density 0.484 g/cc Water pore volume 0.95 cc/g B_E.T surface area 308 m2/g Catalyst B was prepared by pore volume impregnation of the support as described in Example 1 followed by air-drying at 121 C for 4 hours and calcination in air flow at 482 C for 2 hours. The catalyst was then sulfurized in-situ via a conventional method using a 54r H,S in hydrogen mixture as described below. Catalyst B was calcined and sulfurized in two separate steps.
Catalyst B was tested under Test Condition 1. The HDS activity of Catalyst B, as WABT required for 88% IIDS, is showr in Figure 1.
Example 3 A commercial 1.3 trilobe extrudate carrier #1 was used to make Catalyst C.
The impregnation solution was prepared by stirring together 21.62 g NiO, 35.2 g MoO3, 9.05 g 86.1% phosphoric acid r:\1e9aI\bg \speca\tha.2a7_pct.doc 14 AMENDED SHEET
.-,r..~..,..-......._ _._ --_ . . - - -and de-ionized water. The volume of the mixture was approximately 166 ml. The mixture was heated, with stirring, to 99 C for about 3 hours until the impregnation solution components were dissolved. The mixture was then aooled to ambient temperature. The volume of solution was adjusted to the pore volume of 200 grams of the support, which was impregnated as described in Example 1. The metal contents loaded were 3.8 tw Ni, 13.6 tw Mo and 2.0 Ww P (dry basis).

The catalyst precursor was dehydrated in air at 99 C
for four hours until the volatile content was 6%. The catalyst precursor was then treated with the ACTICATm process without employing any calcination steps. The resultant catalyst is referred to as Catalyst C.
Catalyst C was tested in Test Condition 1 versus a cottanercial catalyst treated with the standard ACTICATm process using separate calcination and pre-sulfurizing steps (Catalyst D) . The HDS activities of Catalysts C and D, as inWABT required for 88% HDS, are shown in Figure 2.

Example 4 The properties of the alumina extrudate (1.2 rnm trilobe) used to make Catalysts E and F was as follows:
Compacted bulk density 0.505 g/cc Water pore volume 0.87 cc/g B.E.T surface area 277 m2/g The impregnation solution was prepared by dissolving 5.25 g NiCfl, and 16 . 67 g ammonium dimolybdate (NFi,) 2MoZO, -(56 .45 %w Mo) in 60 ml of 14.8% NH, solution in water. The volume of the solution was adjusted to 87 cc, and 100 g of the support was impregnated as described in Example 1. The metal loading was 2.3 tw Ni and 8.0 Ww Mo (dry basis) . The catalyst precursor was dehydrated overnight in air at 127 C to remove r:\legal\bga\epeca\th1287_pc:t.doe 15 AMENDED SHEET

excessive moisture and ammonia, then cooled to ambient temperature and divided into two equal portions. The first portion was directly presulfurized using the ACTIC.AT process without any calcination step to remove residual moisture and load sulfur into the catalyst, as described in Example 3. The resultant catalyst is denoted as Catalyst E. The second portion was conventionally calcined at 482 C for 2 hours, and sulfurized in-situ using an Ii,/H,S gas mixture (Catalyst F) .
Catalyst E was tested versus Catalyst F using Test Condition 1. The HDS relative volumetric activity (derived from the second order reaction rate constants for the two catalysts) was 25* higher for Catalyst E compared to that for Catalyst F at 400 hours on stream.
Example 5 Catalyst C was tested using Test Condition 2 versus a commercial catalyst (Catalyst G) which used the same carrier as that for Catalyst C. The (pre-calcined) commercial catalyst was sulfurized in-situ using an H./IizS gas mixture. The comparison test results are presented on Figures 3 and 4.

Example 6 Catalyst C was tested versus a commercial reference catalyst (same as catalyst D except the sulfurization of the pre-calcined cataiyst was performed in-situ using an H2/HaS gas mixture). The commercial catalyst is denoted as Catalyst H.
HDS activitiea of the two catalysis were compared using Teat Condition 3. The HDS relative volumetric activity (derived from the second order reaction rate constants for the two catalysts) was 25% higher for Catalyst C compared to that fcr Catalyst H at 400 hours on stream.

Example 7 A commercial 1.3 trilobe extrudate carrier #2 was used to make Catalyst I. The impregnation solution was prepared r:\legal\bge\apecs\th,~287rpct.doc 16 AMENDED SHEET
! T Jc = ---- -- ... . . . _ _ ... - -' - - - =

using the procedure described in Sxample 6; however the metal contents (dry basis) were as follows: 13.0*w Mo, 3.0tw Ni, 3.2%w P. The catalyst precursor was dehydrated in air at 99 C for three hours until the volatile content was 8$. The catalyst precursor was then treated with the ACTICAVO process without any additional drying/calcination s*_eps.
Catalyst I was tested using Test Condition 4 versus a coctmiercial catalyst (Catalyst J) having the same carrier and percentage of metals as Catalyst I. The (pre-calcined) commercial catalyst was sulfurized in-situ using an H,JR,S gas mixture. The EDN relative volumetric activity (derived from the first order reaction rate constants for the two catalysts) was 20% higher for Catalyst I compared to that for Catalyst J
at 200 hours on stream at 343 C WABT, arid 40Ir higher for the catalyst I at 300 hours at 363 C.

Example B - Comparative A commercial catalyst treated with standard ACTICAT
process using separate calcination and pre-sulfurizing steps (Catalyst D; was compared with the same type of coTwercial catalyst sulfurized in-situ with H2/H2S gas mixture (Catalyst K), using Test Condition 1. Catalyst D and Catalyst K were statistically undistinguishable in HDS and HDN performance during the test run (1400 hours on stream), demonstrating that effects seen due to the process of the invention are not due to differences in presulfurizing process.
As shown in the Examples and seen in Figures 1-4, the HDS and HDN activities of the catalysts prepared by the process of the inventior, (Catalysts A, C, E and I) are significantly higher than that of the catalysts prepared by standard processes utilizing separate steps for drying, calcinirYg and sulfurizing. Consequently, substantially lower sulfur and/or nitrogen content in the petroleum product is achievable by r:\legal\bge\mpeca\th].7A7_pct_dac 1 7 AMENDED SHEET

combining the drying/sulfurizing steps and eliminating the calcining step. A higher activity catalyst rnakes it possible to operate a commercial unit at less severe conditions while producing on-spec product. This in turn should increase the catalyst life and decrease operating costs.

r:\1ega1\bgs\specs\th1287_pct.doc ~.8 AMENDED SHEET

Claims

CLAIMS:

1. A process for preparing a catalyst, said process comprising:
providing a porous support;
combining said support with one or more catalytically active metals by impregnation, co-mulling or co-precipitation, thereby forming a catalyst precursor having a volatile content greater than 0.5 percent; and reducing the volatile content of the catalyst precursor in one or more steps, wherein at least one volatile content reduction step is performed in the presence of at least one sulphur containing compound;
wherein said catalyst precursor does not reach a temperature in the range of from 400°C to 600°C prior to said at least one combined volatile content reduction-sulfurizing step.

2. A process according to claim 1, wherein said at least one volatile content reduction-sulfurizing step is completed ex-situ or in-situ.

3. A process according to claim 1 or claim 2, wherein the one or more catalytically active metals is selected from Group VI and Group VIII of the Periodic Table and the catalyst is a hydrotreating catalyst suitable for hydrotreatment of a hydrocarbonaceous feedstock.

4. A process according to claim 3, wherein said one or more catalytically active metals is selected from molybdenum, tungsten, cobalt, nickel, and oxides, sulfides, and mixtures thereof.

5. A process according to any one of claims 1 to 4, wherein said porous support is selected from alumina, silica-alumina, silica, titania, boria, zeolites, zirconia, magnesia and combinations thereof.

6. A process according to any one of claims 1 to 5, wherein prior to said at least one combined volatile content reduction- sulfurizing step, said catalyst precursor has a volatile content in the range of from 3 to 10%.

7. A process according to claim 6, wherein said catalyst precursor has a volatile content in the range of from 6 to 10%.

8. A process for catalytic hydrotreatment of a heteroatom-contaminated hydrocarbonaceous feedstock, said process comprising contacting said feedstock at elevated temperature and elevated pressure in the presence of hydrogen with one or more catalysts beds; wherein at least one catalyst bed contains a catalyst prepared by the process comprising combining a porous support with one or more catalytically active metals selected from Group VI and Group VIII of the Periodic Table, by impregnation, co-mulling or co-precipitation, thereby forming a catalyst precursor having a volatile content greater than 0.5 percent, and reducing the volatile content of the catalyst precursor in one or more steps, wherein at least one volatile content reduction step is performed in the presence of one or more sulphur containing compounds; and wherein said catalyst precursor does not reach a temperature in the range of from 400°C to 600°C prior to said at least one combined volatile content reduction-sulfurizing step.

9. A process according to claim 8, wherein at least one volatile content reduction step occurs during a liquid-phase sulfurization process.

10. A catalyst obtained by the process comprising combining a porous support with one or more catalytically active metals, by impregnation, co-mulling or co-precipitation, thereby forming a catalyst precursor having a volatile content greater than 0.5 percent; and reducing the volatile content of the catalyst precursor in one or more steps, wherein at least one volatile content reduction step is performed in the presence of at least one sulphur containing compound; wherein said catalyst precursor does not reach a temperature in the range of from 400°C to 600°C
prior to said at least one combined volatile content reduction-sulfurizing step.

11. A catalyst according to claim 10, wherein the catalyst is a hydrotreating catalyst suitable for hydrotreatment of a hydrocarbonaceous feedstock and wherein said one or more catalytically active metals is selected grom Group VI and Group VIII of the Periodic Table.

12. A catalyst according to claim 10 or claim 11, wherein said one or more catalytically active metals is selected from molybdenum, tungsten, cobalt, nickel and oxides, sulfides, and mixtures thereof and wherein said porous support is selected from alumina, silica-alumina, silica, titania, boria, zeolites, zirconia, magnesia and combinations thereof.