CA2066453A1 - High activity slurry catalyst process - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A high viscosity index lubricating oil is produced from heavy oils by using a high activity slurry catalyst process.
The catalyst is produced by sulfiding aqueous Group VIB
metal compounds to a dosage greater than 8 SCF hydrogen sulfide per pound of Group VIB metal. The Group VIB metal can be promoted with Group VIII metals to enhance its activity.

High activity slurry catalysts for hydroprocessing heavy hydrocarbon oils are produced from Group VIB metal compounds by sulfiding an aqueous mixture of the metal compound with from greater than about 8 to about 14 SCF of hydrogen sulfide per pound of Group VIB metal.

The hydroprocessing of heavy oils is improved by the use of a high activity slurry catalyst prepared by sulfiding an aqueous Group VIB metal compound with a gas containing hydrogen sulfide to a dosage greater than 8 SCF of hydrogen sulfide per pound of Group VIB metal. After introducing the slurry catalyst into the heavy oil, and subjecting the mixture to elevated temperatures and partial pressures of hydrogen, the mixture is treated in a fixed or ebullated bed of hydrodesulfurization/hydrodemetalation catalyst under hydroprocessing conditions.

Description

05 This application is a continuation-in-part of U- S. Serial 06 No. 548,157 filed July 5, 1990, U.S. Serial No. 586,622 07 filed September 21, 1990 and U.S. Serial No. 621,501 filed 08 December 3, 1990.

This application is also a continuation-in-part of 11 U. S. Serial No. 388,790 filed August 2, l9a9, which is a 12 continuation-in-part of U. S. Serial No. 527,414 filed 13 August 29, 1983 (now USP 4,557,821). This application is 14 also a continuation-in-part of U. S. Serial No. 252,839 15 filed September 30, 1988, which is a continuation-in-part of 16 U. S. Serial No. 941,456 filed December 15, 1986 (now 17 USP 4,857,496), which is a continuation-in-part of 18 U. S. Serial No. 767,767 filed August 21, 1985 (abandoned) 19 which is a continuation-in-part of U. S. Serial No. 527,414 20 filed August 29, 1983 (now USP 4,557,821). This application 21 is also a continuation-in-part of U. S. Serial No. 275,235 22 filed November 22, 1988, which is a continuation-in-part of 23 U. S. Serial No. 767,822 filed August 21, 1985 (abandoned) 24 which is a continuation-in-part of U. S. Serial No. 527,414 25 filed August 29, 1983 (now USP 4,557,821). Related 26 applications include U. S. Serial No. 767,760 filed 27 August 21, 1985 (now USP 4,824,821) also a continuation-28 in-part of U. S. Serial No. 527,914 filed August 29, 1983;
29 U. S. Serial No. 767,768 filed August 21, 1985 (now USP 4,710,486), also a continuation-in-part of U. S. Serial 31 No. 527,414 filed August 29, 1983; and U. S. Serial 32 No. 767,821 filed August 21, 1985 (now USP 4,762,812), also 33 a continuation-in-part of U. S. Serial No. 527,414 filed 34 August 29, 1983.

~ tJ-3~iC.i 03 This invention relates to the catalytic hydroprocessing of 04 heavy hydrocarbon oils including crude oils, heavy crude 05 oils and residual oils as well as refractory heavy 06 distillates, including FCC decanted oils and lubricating 07 oils. It also relates to the hydroprocessing of shale oils, 08 oils from tar sands, and liquids derived from coals. The 09 invention relates to a catalyst for the hydroprocessing of such hydrocarbonaceous feedstocks, the use of such 11 catalysts, and the preparation of such catalysts.

13 In U. S. Serial No. 527,414 filed August 29,1983 (now 14 USP 4,557,821), a parent application of the present application, a catalytic means of hydroprocessing heavy oils 16 was revealed which employs a circulating slurry catalyst.
17 The catalyst comprised a dispersed form of molybdenum lB disulfide prepared by reacting aqueous ammonia and 19 molybdenum oxide to form an aqueous ammonium molybdate which was reacted with hydrogen sulfide to form a precursor 21 slurry. The precursor slurry was mixed with feed oil, 2Z hydrogen and hydrogen sulfide and heated under certain 23 conditions. A variety of dosages of hydrogen sulfide 24 expressed as SCF of hydrogen sulfide per pound of molybdenum were taught to be useful in forming the precursor slurry 26 (Column 3). From 2-8 SCF/L~ were preferred ~Column 4). It 27 was found to be necessary to mix the slurry with oil in the 28 presence of both hydrogen and hydrogen sulfide in order to 29 obtain a catalytically active slurry catalyst (Columns 11-12). The oil-slurry mixture was then sulfided 31 with hydrogen and hydrogen sulfide at at least two 32 temperatures (Column 24) under certain conditions. The feed 33 and catalyst, with water added were charged to the 34 hydroprocessing reactor. Water introduction was deemed ~3~ ~ ~J ~i 01 beneficial (Columns 26-27) for certain purposes, as was 02 nickel addition to the slurry catalyst (Columns 42-44).

04 In U. S. Serial No. 941,456 filed December 15, 1986 05 (USP 4,857,496), a parent application of the present 06 application, is described a sulfiding process in which there 07 are two or three heating steps providing time-temperature 08 sequences to complete the preparation of the final catalyst 09 prior to flowing the feed to the higher temperature hydroprocessing reactor zone. Each sulfiding step was 11 operated at a temperature higher than its predecessor.
12 Ammonia was removed from an intermediate stage of catalyst 13 preparation before the addition of feed oil and further 14 sulfiding.
16 U. S. Serial No. 767,760 filed August 21, 1985 17 (USP 4,824,821) also a continuation-in-part of 18 U. S. Serial No. 527,414 filed August 29, 1983 describes the 19 promotion of a Group VIB slurry catalyst by the addition of a Group VIII metal such as nickel or cobalt, to the aqueous 21 ammonia compound after sulfiding is underway.

23 U. S. Serial No. 767,768 filed August 21, 1985 24 (USP 4,710,486) also a continuation-in-part of U. S. Serial No. 527,414 filed August 29, 1983 describes the specific 26 regulation of the amount of sulfiding occurring in 27 intermediate temperature sulfiding steps by stoichiometric 28 replacement of oxygen associated with the Group VIs metal 29 with sulfur up to fifty to ninety-five percent replacement.
At least three stages of sulfiding were preferred with 31 additional replacement of oxygen by sulfur in the high 32 temperature step.

01 U. S. Serial No. 767,821 filed August 21, 1985 02 (USP 4,762,~12) also a continuation-in-part of U. S. Serial 03 No. 527,414 filed August 29, 1983 described a process for 04 the recovery of spent molybdenum catalysts.

06 A parent application of the present application U. S. Serial 07 No. 275,235 filed November 22, 1988 described a Group VIB
08 metal sulfide slurry catalyst for hydroprocessing heavy oils 09 or residual oil which has a pore volume in the 10-300 angstrom radius pore size range of at least 0.1 cc/g.

12 In USP 4,376,037 and USP 4,389,301 a heavy oil is 13 hydrogenated in one or two stages by contacting the oil with 14 hydrogen in the presence of added dispersed hydrogenation catalysts suspended in the oil, as well as in the additional 16 presence of porous solid contact particles. In the 17 two-stage version, the normally liquid product of the first 18 stage is hydrogenated in a catalytic hydrogenation reactor.
19 The dispersed catalyst can be added as an oil/water emulsion prepared by dispersing a water-soluble salt of one or more 21 transition elements in oil. The porous contact particles 22 are preferably inexpensive materials such as alumina, porous 23 silica gel, and naturally occurring or treated clays.
24 Examples of suitable transition metal compounds include (NH4)2 MoO4, ammonium heptamolybdate and oxides and sulfides 26 of iron, cobalt and nickel. The second reaction zone 27 preferably contains a packed or fixed bed of catalysts, and 28 the entire feed to the second reaction zone preferably 29 passes upwardly through the second zone.

31 In USP 4,564,439 a heavy oil is converted to transportation 32 fuel in a two-stage, close-coupled process, wherein the 33 first stage is a hydrothermal treatment zone for the 34 feedstock mixed with dispersed demetalizing contact 01 particles having coke-suppressing activity, and hydrogen;
02 and the second stage closely coupled to the first, is a 03 hydrocatalytic processing reactor.

05 The specifications of all of the foregoing U. S. Patent 06 applications are incorporated herein by reference as if 07 fully set forth in ipsis verbis.

og FIELD OF THE INVENTION

11 Increasingly, petroleum refiners find a need to make use of 12 heavier or poorer quality crude feedstocks in their 13 processing. As that need increases the need also qrows to 14 process the fractions of those poorer feedstocks boiling at lS elevated temperatures, particularly those temperatures above 16 1000F, and containing increasingly high levels of 17 contaminants, such as undesirable metals, sulfur, and 18 coke-forming precursors. These contaminants significantly 19 interfere with the hydroprocessing of these heavier fractions by ordinary hydroprocessing means. The most 21 common metal contaminants found in these hydrocarbon 22 fractions include nickel, vanadium, and iron. The various 23 metals deposit themselves on hydrocracking catalysts, 24 tending to poison or de-activate those catalysts.
Additionally, metals and asphaltenes, and coke-precursors 26 can cause interstitial plugging of catalyst beds, reduce 27 catalyst life, and run length. Moreover, asphaltenes also 28 tend to reduce the susceptibility of hydrocarbons to 29 desulfurization processes. Such de-activated or plugged catalyst beds are subject to premature replacement.

ff~!~f~J '-;, 01 As a practical matter the run length in a fixed bed resid 02 desulfurization process is limited by coke and/or metals 03 loadings of the catalyst. Improved fixed bed performance, 04 catalyst life and improved 1000F+ conversions can be 05 obtained by reducing the levels of metals and coke 06 precursors which plug the pores and/or penetrate the 07 catalyst pore volume containing active catalytic sites.

09 It would be advantageous to cure these problems with the least upset to conventional processing techniques and at the 11 lowest cost. If, for example, dispersed, consumable 12 catalysts are used, the catalyst should be effective at the 13 lowest possible concentration to reduce the cost of 14 catalytic treatment.

16 For the processing of heavy oils characterized by low 17 hydrogen to carbon ratios (i.e. less than about 1/8 by 18 weight) and high carbon residues, asphaltenes, nitrogen, 19 sulfur and metal contaminant contents, it would be advantageous if the parameters for the preparation of a high 21 activity slurry catalyst were known.

23 It would also be advantageous if the performance of existing 24 fixed bed reactors could be increased by the use of slurry catalysts.

27 A lubricat$ng oil base stock boils above about 500F and 28 below about 1300F, and will generally have a kinematic 29 viscosity greater than about 2cS (measured at 100C). A
Viscosity Index of about 90 or greater is preferred 31 (ASTM D 2270-86). The lubricating oil base stock may be 32 recovered as a distillate or distillate fraction from an 33 upgrading zone, involving processes such as hydrocracking or 34 solvent extraction.

,~" '; ~ ?~ 1. . j 01 Generally, lubricating oil base stocks prepared from 02 hydrocarbon feedstocks boiling above 1000F require 03 pretreatment prior to the upgrading zone. One such 04 pretreatment method is solvent deasphalting, which removes 05 heavy hydrocarbonaceous components which otherwise form 06 precipitates during lube oil processing. The use of these 07 pretreatment methods adds additional processing steps over 08 the process of this invention, and leads to low yields of 09 lubricating oil stocks.

11 Distillates suitable for use as lubricating oil base stocks 12 may be further treated to meet specific quality 13 specifications. Wax may be removed to lower the pour point.
14 Dewaxing may be carried out by conventional means known in the art such as, for example, by solvent dewaxing or by 16 catalytic dewaxing. Distillates recovered from the 17 upgrading zone may also be further treated with a catalyst 18 in the presence of hydrogen to remove hydrocarbonaceous 19 components which are subject to oxidation and formation of color bodies during storage.

22 It would also be advantageous if a slurry catalyst process 23 produced a lubricating oil base stock with high viscosity ~4 index from heavy oils.

28 The present invention provides a high activity catalyst 29 which is prepared by dispersing a slurry catalyst in a hydrocarbonaceous oil for hydroprocessing. The present 31 process has the advantage over conventional processes of 32 achieving higher conversion of nitrogen, sulfur, metals and 33 bottoms than fixed bed resid desulfurization, thermal or 34 existing slurry processes.

h~ ~: S~

01 The process comprises: sulfidinq an aqueous mixture of a 02 Group VIB metal compound with a gas containing hydrogen 03 sulfide to a dosage greater than about 8, preferably from 04 greater than about 8 up to 14 SCF of hydrogen sulfide per 05 pound of Group VIB metal to form a slurry; and mixing the 06 slurry with feed oil and a hydrogen-containing gas at 07 elevated temperature and pressure. Twelve SCF hydrogen 08 sulfide corresponds to about 1 mole of molybdenum per 09 3 moles of sulfur.

11 Thc invention also comprises the preparation of a dispersed 12 Group VIB metal sulfide catalyst by sulfiding an aqueous 13 mixture of a Group VIB metal compound with a gas containing 14 hydrogen and hydrogen sulfide, to a dosage from greater than about 8 to about 14 SCF of hydrogen sulfide per pound of 16 Group VIB metal to form a slurry; adding a Group VIII metal 17 compound to the slurry; and mixing the slurry and Group VIII
18 metal compound with a feed oil and a hydrogen-containing gas 19 at elevated temperature and pressure. The inclusion of Group VIII metal compounds improves the denitrogenation 21 capability of the slurry catalyst.

23 A high viscosity index lubricating oil is produced from 24 heavy oils by using our high activity slurry catalyst process. The lubricating oil which is produced is of 26 surprisingly high viscosity index and good viscosity. In 27 our process~ the highly active Group VIB metal sulfide 28 catalyst slurry is contacted with feed oil and a hydrogen-29 containing gas at elevated temperature and pressure; and separating from the product an oil fraction boiling above 31 about 650~ which is subsequently dewaxed. The process also 32 comprises adding a Group VIII metal compound to the slurry;
33 contacting the slurry catalyst containing the Group VIB and 34 the Group VIII metal with a feed oil and a hydrogen-t " 3 01 containing gas at elevated temperature and pressure to 02 effect hydroprocessing of said feed oil; and separating a 03 product lubricating oil base stock boiling above about 04 650F, which is preferably subsequently dewaxed.

06 The lubricating oil fraction is of high viscosity index and 07 good viscosity characteristics for lubricating oll baqe 08 stock.

Another process using the active catalyst slurry comprises 11 introducing the heavy oil, an active catalyst slurry and a 12 hydrogen-containing gas at elevated temperature and pressure 13 into a fixed or ebulating bed of particulate 14 hydrodesulfurization- hydrodemetalation catalyst at a temperature greater than about 700F, preferably in upflow 16 relationship to said bed. Preferably a Group YIII metal 17 compound is added to the slurry before mixing with the heavy 18 feed oil. Separate porous contact particles can be added to 19 the heavy oil feedstock.

21 In a two-stage process embodiment of the present invention, 22 the heavy oil is contacted in a first-stage with the active 23 catalyst slurry and hydrogen at a temperature and for a time 24 sufficient to achieve measurable thermal cracking in the product stream. Then the effluent of the first-stage is 26 contacted with a fixed or ebullated bed of 27 desulfurization-demetalation catalyst and hydrogen gas in a 28 second-stage. The second-stage catalyst bed may be graded 29 by catalyst activity and/or temperature profile to promote uniform metal deposition, and preferably the effluent stream 31 flows upwardly through the second-stage catalyst bed. In 32 ebullating bed8, the catalyst is graded by staged reactors.
33 In our process the metals are deposited on the slurry 34 catalyst and this catalyst provides the advantage of 01 demetalation at lower levels of conversion of the 1000F+
02 fraction of the heavy oil.

04 Our process provides the advantage that when the 1000F+
05 conversion of the heavy feed oil is less than 70~, the coke 06 yield is less than about 1.0%. Even at conversions as high 07 as 90%, and at low slurry catalyst concentrations 08 (100-1000 ppm), the coke yield is less than 2.5%.

BRIEF DESCRIP~ION OF THE DRAWINGS

12 Figure 1 shows the denitrogenation activity of various 13 catalysts pretreated at essentially the same ammonia to 14 molybdenum ratio but sulfided to various extents. Figures 2-3 show the denitrogenation rate constant, and API gravity 16 increase as a function of the extent of sulfiding, 17 respectively. Figure 4 indicates the molybdenum sulfided 18 catalyst precursors which yield active catalysts are aqueous 19 gels. Figure 5 shows the benefit of promoting the active catalysts of this invention with a Group VIII metal.
21 Figure 6 graphs the amount of coke produced by the present 22 invention and the amount of coke produced by a competitive 23 process, as coke yield (weight percent~, versus the amount 24 of the 1000F+ fraction of residua converted to lighter products, as volume percent.

27 Figure 7 qraphs the percent of vanadium metal removed from 28 residua by the present invention and a competi~ive process, 29 versus the 1000F+ fraction conversion of the residua.

04 The activity of the Group VIB metal slurry catalyst is a 05 function of the preparation conditions. The preferred 06 Group VIB metal is molybdenum, but tungsten co~pounds are 07 also catalytically useful. Molybdenum is used herein for 08 purposes of exemplification and does not exclude other 09 Group VIB compounds. The high activity slurry catalyst used in the present invention is described in U.S. Serial 11 No. 548,157, filed July 5, 1990, the disclosure of which has 12 been incorporated herein by reference.

14 In an improved process for the preparation of molybdenum sulfide slurry catalyst, sulfiding of the aqueous solution 16 formed by pretreatment of molybdenum oxide with aqueous 17 ammonia is carried out with a dosage of at least a SCF of 18 hydrogen sulfide per pound of molybdenum. When this dosage 19 of hydrogen sulfide is used, it is not necessary to have hydrogen sulfide present in the recycled gas stream during 21 hydroprocessing. Furthermore, the activation of the 22 catalyst appears independent of the ratio of ammonia to 23 molybdenum used to form the aqueous mixture.

HIGH ACTIVITY CATALYST

27 We have found that the activity of the final Group VIB metal 28 catalyst is a special function of the activation conditions 29 used to transform the starting Group VIB compound to the final, active catalyst. In the following we will by way of 31 exemplification and discussion refer to the preferred 32 Group VIB metal, molybdenum and its compounds as typical of 33 our slurry catalyst. However, the reference to molybdenum 34 is by way of preference and exemplification only, and is not 01 intended to exclude other Group VIB metals and compounds 02 thereof.

04 AS an improvement of other methods of preparing the catalyst 05 of the present invention we have found that activation of 06 the catalyst occurs by sulfiding the aqueous solution formed 07 by pretreatment with aqueous ammonia to at least 8 SCF of 08 hydrogen sulfide per pound of molybdenum. with this degree 09 of sulfiding it is no longer necessary to have hydrogen sulfide present in the recycled gas stream during 11 hydroprocessing. Furthermore, the activation of the 12 catalyst is achieved relatively independent of the 13 ammonia-to-molybdenum ratio used to form the aqueous 14 mixture.
16 SUlfiding 18 Catalyst activity is achieved when the extent of sulfiding 19 is from greater than about 8 up to about 14 SC~ of hydrogen sulfide per pound of molybdenum. This sulfiding dosage 21 produces a catalyst precursor characterized by a sulfur-22 to-molybdenum mole ratio of about 3. The effect of 23 sulfiding on catalyst activation is demonstrated in the 24 first set of examples. In these examples, two types of catalyst were prepared by first reacting molybdenum oxide 26 with aqueous ammonia at identical conditions and with the 27 same amount of ammonia. The aqueous mixture was then 28 sulf~ded in the absence of added oil. The catalysts differ 29 in the extent of sulfiding provided. The first type was sulfided to a dosage of 2.7 SCF of hydrogen sulfide per 31 pound of molybdenum (SC-21). The second type of catalyst 32 was sulfided beyond 12 SCF of hydrogen sulfide pcr pound of 01 molybdenum ( SC-25-2). The conditions used to pretreat with 02 ammonia and sulfide these catalysts are summarized below.

04 CATA~YST PREPARATION:

o65 Catalyst, SC: -21 -25-2 07 Pretreatment NH3/Mot lb/lb. 0.23 0.23 08 sulfiding:
09 H2S/Mo~ SCF/lb. 2.7 14.0 Temperature, F 150 150 Pressure, psig. 30 400 11 Sulfiding Gas:
Composition, %

13 Hydrogen 88-90 88-90 Tables IA-IB compare the results of two runs performed on 16 the same feedstock and at identical conditions with both the 17 undersulfided catalyst SC-21 and the catalyst, SC-25-2.
18 Catalyst activation is evident from the hydrogen 19 consumption, denitrogenation, desulfurization, demetalation and 975F+ conversion results. Hydrogen consumption was 21 increased from 584 to 1417 SCF per barrel, desulfurization 22 from 38 to 89 weight percent, denitrogenation from 21 to 23 84 weight percent, demetalation from 66 to 99 weight percent 24 and 975F+ conversion from 77 to 92 volume percent.

Feedstock <----- Hvy. Arabian----------->

05 Catalyst SC-21 SC-25-2 06 Cat. to oil ratio 0.0213 0. 0193 o87 Molybdenum,wt./wt.
09 LHSV 0. 59 0.56 Temperatures, F.
Pretreater: 682. 682.
13 Reactor: 808. 811.
14 Pressures:
Rx. Inlet, psig: 2842. 2748.
17 H2 partial pressures, psi 1958. 1498.
18 H2S partial pressure, psi 150. 365.
9 Recycle gas:

21 Gas rate, SCF/Bbl. 6650. 5419.

~ j -CONVERS ~ ONS

04 Feedstock ~------- Hvy. Arabian --~
Conversions:

07 Hydrogen Consumption, SCFB: 584. 1417.
08 Conversion:

Vacuum Resid, % as 53.7 71.4 11 975F+ vol %
12 Total: 76.6 92.1 13 ~esulfurization, wt. % 38. 89.
15 Denitrogenation, wt. % 21. 84.
16 Demetalation, wt. ~ 66. 99.
17 Nickel Removal, wt. % 61. 99.

19 Vanadium Removal, wt. % 67. 99.

21 Catalysts sulfided at higher sulfiding dosages than about 22 12-14 SCF of hydrogen sulfide per pound of molybdenum yield 23 neither higher nor lower catalyst activities when tested in 24 batch operations. Figure 1 shows the denitrogenation 25 activities various catalysts pretreated at essentially the 26 same ammonia to molybdenum ratio but presulfided with 27 various dosages of hydrogen sulfide. These pretreated and 28 sulfided catalysts were screened in a batch reactor with no 29 added hydrogen sulfide and with a feed that contained little sulfur. No further sulfiding was provided to the catalyst 31 aside from that performed in the presulfiding step in the 32 absence of oil. The results shown in Figure 1 illustrate W ;5 ;i '~

01 the criticality of sulfiding this catalyst to greater than 02 8 SCF H2S per pound of molybdenum.

04 Ammonia Pretreatment:

06 The catalysts were pretreated over a wide range of ammonia 07 to molybdenum ratios, from materials prepared without 08 ammonia (0 ammonia to molybdenum ratio) to catalysts 09 pretreated to 0.35 pound of ammonia per pound of molybdenum.
The results indicate that catalyst activity is independent 11 of the ammonia to molybdenum ratio used to form the slurry 12 catalyst. Although a slight optimum when the ammonia to 13 molybdenum ratio was about 0.16 was observed, catalysts were 14 produced even when aqueous slurries of molybdenum oxide were appropriately sulfided without ammonia pretreatment.
16 However, pretreatment with ammonia is preferred because 17 better control of the particle size is achieved when the 18 molybdenum oxide is dissolved in aqueous ammonia.

Hydrogen Sulfide Requirements During Hydroprocessing:

22 In prior work it was required to include the recycling of a 23 hydrogen-hydrogen sulfide stream separated from the 24 hydroprocessing zone wherein the hydrogen sulfide partial pres8ure was at least 20 psi and the circulation of hydrogen 26 sulfide was greater than 5 SCF per pound of molybdenum.
27 However, in the present invention, by increasing the 28 sulfiding dosage, in the absence of oil, to values of from 29 about greater than 8 to about 14 SCF of hydrogen æulfide per pound of molybdenum, not only are active slurry catalysts 31 produced, but the need of having hydrogen sulfide present in 32 the recycled gas stream is eliminated.

01 Table II shows and compares various runs performed with both 02 undersulfided catalyst and the catalysts of this invention.
03 As can be observed, stable and high activity catalysts have 04 been obtained over a wide range of hydrogen sulfide partial 05 pressures and circulation rates at the reactor inlet.
06 Active catalysts, have been obtained at hydrogen sulfide 07 partial pressures from 271 psi to 3.5 and circulation rates oa from 78 to as low as 5 SCF of hydrogen sulfide per pound of 09 molybdenum.

11 Effect of Hydrogen Partial Pressure During Sulfidin~:

13 In the examples given above all the catalysts were sulfided 14 with hydrogen sulflde contained in a hydrogen gas. I have now demonstrated that active molybdenum sulfide catalysts 16 can be produced when the culfiding step is performed in the 17 absence of hydrogen. To study this effect a series of 18 catalysts were prepared at various sulfiding dosages with a 19 gas containing no hydrogen. The catalysts were prepared using conventional sulfiding techniques described in the 21 background section, except that the sulfiding gas stream 22 contained no hydrogen. The sulfiding gas consisted of 20%
23 by mole of hydrogen sulfide and 80~ nitrogen. The resulting 24 catalysts were tested in a batch microactivity unit for their denitrogenation, hydrogenation, and desulfurization 26 activities. The catalysts were tested at typical catalyst 27 conditions with the gas charge consisting of pure hydrogen.
28 The results from this study were compared to those obtained 29 with catalysts sulfided under hydrogen partial pressure.

31 Figures 2-1 show the denitrogenation rate constant, and API
32 gravity increase as a function of the extent of sulfiding.
33 Also contained in these figures are similar results obtained 34 with catalysts sulfided with a hydrogen sulfide and hydrogen ~ 3 01 gas mixture having the same hydrogen sulfide composition as 02 that used in this study. From the denitrogenation results, 03 it is evident that active catalysts were obtained regardless 04 of the hydrogen partial pressure.

06 Although in both cases active catalysts were produced, 07 activation of the slurry catalyst occurred at a lower 08 sulfiding dosage, i.e. at 8-10 SCF hydrogen sulfide per 09 pound of molybdenum, when the catalysts were produced under no hydrogen partial pressure. This value was slightly lower 11 than that sulfiding dosage required to activate thè catalyst 12 when it is activated under hydrogen partial pressure, 13 i.e. at 12-14 SCF of hydrogen sulfide per pound of 14 molybdenum. Higher API gravities and amounts of hydrogen used to upgrade the liquid product were obtained with 16 catalysts sulfided under hydrogen partial pressure.

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" ~3 i3 01 Effect of Sulfiding On Continuous Operations:

03 We have demonstrated that activation of the slurry catalyst 04 occurs by sulfiding aqueous solutions or mixtures of ammonia 05 molybdate and molybdenum oxides. Activity increases as the 06 extent of sulfiding is increased. Maximum activity is 07 obtained when the extent of sulfiding is about 12 ~CF of 08 hydrogen sulfide per pound of molybdenum. Catalyst 09 precursors sulfided at higher sulfiding dosages than about 14 SCF of hydrogen sulfide per pound of molybdenum produce 11 neither higher nor lower activities when tested in batch 12 operations. Because the difference between batch and 13 continuous operations is important, the effect of sulfiding 14 dosage on the activity of the system was studied in continuous operation on heavy oil feeds. Similar to the 16 results in batch operations, maximum catalyst activation 17 occurred when the catalyst was sulfided to a value of about 18 12 SCF of hydrogen sulfide per pound of molybdenum. But 19 unlike the results obtained in batch reactor studies, the activity of the catalyst system in continuous operations was 21 found to decrease as the catalyst precursor was sulfided 22 above about 14 SCF of hydrogen sulfide per pound of 23 molybdenum dosage.

For catalyst pretreated at an ammonia to molybdenum weight 26 ratio of 0.23, incipient gel formation occurs at a sulfiding 27 dosage of about 12-14 SCF of hydrogen sulfide per pound of 28 molybdenum. The effect of increasing the sulfiding dosage 29 beyond this dose is to thicken the catalyst precursor aqueous gel. NO further sulfur uptake is believed to be 31 achieved by increasing the sulfiding process beyond this 32 dosage. While we do not endorse nor intend to be limited by 33 any theory, the loss of activity observed in the continuous 34 operation at higher sulfiding dosages is believed to be 01 caused by the larger particles produced at higher sulfiding 02 dosages. Consequently, catalyst activity loss at higher 03 sulfiding dosages is believed to be due both to the decrease 04 in reactive volume caused by catalyst build-up and by the 05 lower surface area of the larger catalyst particles.

07 Composition of Matter:

09 Although the active catalyst precursor is characterized by a sulfur to molybdenum mole ratio of about 3, the final 11 catalyst is believed to be an active form of molybdenum 12 disulfide. Decomposition of the catalyst precursor to the 13 final catalyst occurs at conditions typical of the heavy oil 14 feed preheaters conventionally used, and requires no further sulfiding for activation. Furthermore, equilibrium 16 calculations indicate that at the reactor conditions 17 employed in slurry operations, molybdenum disulfide is the lB favored species.

The molybdenum sulfided catalyst precursors which yield 21 active catalysts are aqueous gels (Figure 4) which appear as 22 an elastic coherent mass consisting of an aqueous medium in 23 which ultramicroscopic particles are either disperæed or 24 arranged in a network. Furthermore, the catalyst activity is independent of pH since the pH of the resulting aqueous 26 precursor gels varies over a wide range.

2~ Optimum catalyst activity occurs when the catalyst precursor 29 is sulfided to the point of incipient gel formation.
Extending the sulfiding above this point produces thick gels 31 which are difficult to disperse into the oil. Thick gels 32 tend to yield large xerogels as the water is vaporized from 33 the gel and the catalyst is transferred to the oil. Large 34 xerogels tend to generate large solid particles when 01 compared with those xerogels prepared from materials 02 produced at the incipient gel formation point. A xerogel is 03 defined as a gel containing little or none of the dispersion 04 medium used.

06 Promotion By Group VIII Metal:

08 As an enhancement of the denitrogenation activity of the 09 active slurry catalyst of the present invention, it is preferred that a Group VIII metal compound be added to the 11 slurry before mixing the slurry with feed oil and a hydrogen 12 containing qas at elevated temperature and pressure. Such 13 Group VIII metals are exemplified by nickel and cobalt. It 14 is preferred that the weight ratio of nickel or cobalt to molybdenum range from about 1:100 to about 1:2. It is most 16 preferred that the weight ratio of nickel to molybdenum 17 range from about 1:25 to 1:10, i.e., promoter/ molybdenum of 18 4-10 weight percent. The Group VIII metal, exemplified by 19 nickel, is normally added in the form of the sulfate, and preferably added to the slurry after sulfiding at a pH of 21 about 10 or below and preferably at a pH of about 8 or 22 below. Group VIII metal nitrates, carbonates or other 23 compounds may also be used. The advances of Group VIII
24 metal compound promotion are illustrated in the following examples. In view of the high activity of the slurry 26 catalyst of the present invention the further promotion by 27 Group VIII metal compounds is very advantageous.

29 To demonstrate the promotion effect of adding Group VIII
metal to the sulfided catalyst, various amounts of nickel 31 and cobalt were added to a molybdenum sulfided catalyst qel 32 as soluble nickel or cobalt sulfate, and mixed.

~ ~Jt~

--2g--01 The promoted catalysts were then tested for their 02 hydrogenation~denitrogenation and desulfurization activity 03 by evaluating their ability to hydrotreat a high nitrogen 04 and aromatic FCC cycle oil. The cycle oil is characterized 05 by the following inspections:
0~

08 FCC Heavy Cycle Oil 9 API Gravity 4.2 Sulfur, wt. % 0.54 11 Nitrogen, ppm 2928 Carbon, wt. % 90.24 12 Hydrogen, wt. % 8.64 14 Figure 5 shows the promotion achieved by nickel for the desulfurization and denitrogenation reactions.

17 Table III summarizes the operating conditions and results 18 from nickel and cobalt promoted active slurry catalysts of 19 my invention.

f5 ~ . ~.

01 TAB~E I I I
02 Feedstock <----FCC Heavy Cycle Oil---->
03 Catalyst 04 Ammonia Pretreatment <-----0.221b NH~/lb. Mo---->
05 Sulfiding Dosage <----13.5 SCF H2S/lb. MO---->
06 Reactor 07 Hydrogen, psi <-------------1950---------->
H2S, psi <--------------0------------>
08 Temperature <-------------725F--------_>
as 10 CatalYst-to-Oil Molybdenum, <-------------1.2----------->
11 wt. % fresh feed Nickel as wt. % Mo 0 2.3 0 9.1 0 13 Cobalt as wt. % Mo O 0 2 .1 0 8 . 8 Desulfurization, wt. %65.6 76.2 75.0 84.5 83.6 Denitrogenation, wt. %71.2 77.6 72.2 80.8 75.4 16 H2 Consumption, 17 SCF/Bbl. 1162 1155 1136 1300 1075 19 HEAVY OIL FEEDSTOCK:
21 The present invention also relates to the manufacture of 22 lubricating oil base stock from heavy oils characterized by 23 low hydrogen to carbon ratios (i.e., less than about 1:8 by 24 weight) and high carbon residues, asphaltenes, nitrogen, sulfur and metal contents. Generally, a heavy oil is that 26 portion of the crude oil boiling above about 650F. Heavy 27 oils are also those oils containing 5% or more of an oil 28 fraction boiling above 1000F. Examples of such heavy oils 29 include atmospheric and vacuum residua, deasphalted oil and heavy gas oil.

~.'"ib~- .

01 CATALYST-TO-FEEDSTOCK OIL RATIO:

03 The catalyst slurry/gel is pumped to the hydroprocessing 04 reactor section where it is contacted with the heavy oil and 05 hydrogen gas. Catalyst in oil concentration of from about 06 O.OS to about 2.0 wt.% molybdenum based on weight of 07 feedstock are preferred when using the high activity slurry 08 catalyst system for lubricating oil production. A catalyst 09 in oil concentration of from about 0.3 to 2.0% is more preferred, and most preferably a catalyst in oil 11 concentration of about 1~ is used.

HYDROPROCESS ING:

The catalyst and heavy oil are contacted at elevated 16 temperatures and pressures. The mixture is reacted at high 17 temperatures and hydrogen partial pressures, normally at 18 about 775F or greater and at a hydrogen partial pressure of 19 about 700-4500 psi, preferably at about ~30F and 2000 psi, respectively. It is under these conditions that high levels 21 of hydrogenation, demetalation, denitrogenation, 22 desulfurization and conversion occur. The observed levels 23 of conversion up to 100% are unexpected when compared to 24 those attained in conventional fixed bed technology at equivalent catalyst to oil ratios. These levels of 26 conversions, surprisingly, produce prime distillate 27 products. In particular, it is surprising that the 650F+
28 products have unusually superior lubricating oil properties.
29 From the product a lubricating oil fraction boiling above about 650F is separated. This fraction, ideally suited to 31 lubricating oil base stock manufacture, may be subsequently 32 dewaxed. Additional denitrification of this fraction may 33 also be recommended, in which event it may be subjected to 34 further hydrofinishing using conventional techniques.

01 DEWAXING:

03 The product of the high activity catalyst hydroprocessing 04 may contain too much wax to be a satisfactory lubricating 05 oil base stock, i.e., have a low pour point, in which event 06 an integral part of our process is a dewaxing step.
07 Dewaxing may be carried out by conventional means such as 08 solvent dewaxing or catalytic dewaxing. To facilitate 09 catalytic dewaxing it may be necessary to remove additional nitrogen from the lubricating oil fraction, in which event 11 the use of a hydrotreating or hydrofinishing step should be 12 incorporated into the overall process prior to dewaxing.

14 It has been found that the final product of the process will have an extraordinarily high viscosity index, especially in 16 view of the nature of the feedstock. While traditionally, 17 lubricating oil base stocks have a viscosity index of about 1~ 100, the present process is found to exceed that figure even 19 when using heavy oil feedstocks.

2a 23 To determine the suitability of the high activity slurry 24 catalyst process to the production of lubricating oil base stocks, the process was applied to a Hondo atmospheric resid 26 feedstock. The feedstock was processed at a catalyst in oil 27 concentration of 1.1 wt.% molybdenum based on fresh feed.
28 The catalyst was promoted with nickel at 10% by weight based 29 on molybdenum. The products were distilled to yield a C5-650F product and a 650F+ product. The 650F+ product 31 was evaluated as a lubricating oil base stock. Table IV
32 contains a summary of the operating conditions used and the 33 yields obtained. Table V summarizes the feed and product 01 inspections. Table VI summarizes the results from the 02 lubricating oil testing proqram.

04 ~A8LE IV

09 Catalyst,Mo/Ni Promoted Cat. to oil concentration Molybdenum, wt./wt., % 1.11 11 Nickel, wt./wt., % .11 Operating conditions 12 Water to oil ratio, wt./wt., %12.6 13 LHSV, Vol.F.F./Hr./Vol.Rx. 0.202 Reactor Temperature, F.,Avg.826.
14 H2 Partial Pressure:
Inlet, psi. 2235.8 Outlet, psi. 1948.4 16 Hydrogen Consumption, SCFB 2272 17 Yields, percent by wt.(vol.) F.F.
Hydrogen -3.48 18 Hydrogen Sulfide 5.80 19 Ammonia 1.10 C1 plus C2 3.05 C plus Cq 4.92 (9 2) C~- 650F Distillates 66.07(81 0) 21 650Fl 22.86(27.0) 22 1000F+ 0 00 (0 0) 23 Coke 0.67 Total 100.00(117.2) Conversions:
Desulfurization, wt. % 98.9 26 Denitrification, wt. % 97.9 27 Demetalation, wt. % 100.0 Conversion of 1000F+, % 100.0 28 Carbon Residue Conversion, %100.0 3t ~: ~ v~ ~ J

FEED AND PRODUCT QUALITIES

Feed <--------PRODUCT-------->
06 Hondo 650F+ C5-650F 650F+

Gravity, API 8.1 42.3 33.4 08 Sulfur, wt. % 5.67 0.08 0.03 09 Nitrogen, ppm 9600 150 424 Hydrocarbon type, vol. % wt. %
Aromatics: ---- 19.3 24.2 Saturates: ---- 80.7 75.0 11 Paraffins: ---- 48.1 31.7 12 Naphthenes: ---- 32.6 43.3 13 Sulfur compounds: ---- ---- 0.8 Total ---- 100.00 100.00 Distillation, FD-1160 T~P D-2887 16 10 % 767 250 652 17 30 % 914 364 687 50% 1032 445 719 18 70 % 521 758 19 90 % 604 828 EP % 666 938 HIGH ACTIVITY OPERATIONS
24LUBE OIL PROCESSING OF THE 650F+ PRODUCT
Solvent Dewaxing:

Yields, wt. %
27 Oil 75. 2 28 Wax 24.8 29 Dewaxed oi l:
30Pour Point, F 5 Viscosity, cS:
31~ 40C(104F) 15.99 3Z@ 100C(212F) 3.789 33Viscosity Index (VI): 130 01 It is noteworthy that there was 100% conversion to 02 1000F- product. Analysis shows a high paraffinic and a low 03 aromatics level. The nitrogen content indicates that the 04 product would most likely need hydrofinishing to remove 05 nitrogen and provide good stability. Upon removal of 06 nitrogen the wax-rich oil is a good candidate for zeolitic 07 dewaxing. Especially noteworthy was the high yield of 08 dewaxed oil having a viscosity index of 130. This viscosity 09 index is extremely high, especially because the viscosity of the oil is so light (i.e., 16cS @40C). In general the VI
11 scale severely underrates low viscosity oils.

13 TWO-STAGE P~OCESS:

An embodiment of the present invention is a two-stage 16 process consisting of a slurry hydroprocessing stage 17 followed by a fixed or ebullated bed desulfurization and 18 demetalation process stage, the slurry hydroprocess is 19 operated at temperatures above the incipient cracking temperature of the heavy oil, normally at temperatures above 21 700F, preferably 800 to 960F, and most preferably 22 830-870F. The second stage or desulfurization reactor is 23 preferably operated in upflow mode to minimize the build-up 24 of slurry catalyst in the bed. Superior performance is achieved in this process by bulk demetalation and carbon 26 residue conversion in the slurry reactor or first stage 27 prior to the heavy oil desulfurization process. Operation 28 of the slurry reactor at temperatures above the incipient 29 cracking temperature of the feed is preferred to achieve this demetalation and carbon residue reduction.

01 Slurry Hydroprocessing:

03 The first stage or slurry hydroprocessing can be achieved in 04 bubble up-flow reactors, coil crackers or ebullated bed 05 reactors. Slurry catalyst systems consist of either small 06 particles, or soluble compounds which yield small particles 07 at reactor conditions dispersed in a feedstock. we 08 distinguish several important types of slurry systems in 09 heavy oil hydroprocessing. Basically, the small solid particles (having a diameter less than 20-50 microns) used 11 in slurry systems can be either catalytically active or 12 inactive for aromatic carbon hydrogenation, or can be 13 auto-catalytic for demetalation, or combinations of the above.

16 Inactive slurry systems are particles which are inactive for 17 aromatic carbon hydrogenation and denitrogenation. Some 18 examples of these materials are mineral wastes and spent FCC
19 catalysts or fines. A known mineral waste material for use in slurry systems is "red mud". In another embodiment of 21 the present invention, porous contact particles 22 (i.e. inactive) are separately added to the heavy oil 23 feedstock prior to hydroprocessing. Examples of such porous 24 contact particles include spent FCC catalyst particles, or fines.

27 Slurry catalyst systems can be produced during 28 hydroprocessing by either thermal decomposition or reaction 29 with hydrogen/hydrogen sulfide gas mixtures. These systems consist of either oil or water-soluble metal compounds. The 31 water-soluble compound can be either mixed directly into the 32 oil or emulsified with added surfactants. Generally the 33 water-soluble compounds are preferred due to their lower 34 cost when compared to the organic compounds.

.

"~

01 Auto-catalytic slurry systems for demetalation reactions are 02 exemplified by such materials as nickel/vanadium oxides or 03 sulfides or oxysulfides which act as demetalation catalysts 04 and can thus be classified as auto-catalytic material~.
05 Addition of nickel and vanadium sulfides to the oil not only 06 increases the demetalation reactions but also initiates the 07 auto-catalytic demetalation reaction.

09 However, the Group VIB metal activated slurry catalyst of the present invention, preferably promoted by Group VIII
11 metal compounds, provides a substantial improvement to a 12 slurry catalyst system's hydrogenation, denitrogenation, 13 carbon residue conversion and demetalation performance. The 14 catalyst precursors prepared by the methods used in this invention are characterized by extremely small particle size 16 distributions. The bulk of these particles are in the 17 sub-micron range.

19 Process Conditions:

21 An embodiment of the present invention operates in one or 22 two stages. In one-stage operation the heavy oil is 23 contacted with the active catalyst slurry and a 24 hydrogen-containing gas at elevated temperatures and pressures and proceeds directly to a fixed or ebullated bed 26 catalytic reactor with sufficient residence time in the 2 catalytic reactor and at temperatures sufficient to achieve 28 measurable thermal cracking rates. The process may be 29 operated in two-stages where the first-stage comprises the contacting of the active catalyst slurry with the heavy oil 31 and a hydrogen-containing gas with sufficient time and 32 temperature in a thermal treatment reactor, such as a 33 thermal coil or a bubble up-flow column or an ebullated 34 reactor, to achieve reasonable thermal cracking rates. Such 01 temperatures for heavy oil feedstocks are normally above 02 about 700F, preferably above 750F.

04 The concentration of the active slurry catalyst in the heavy 05 oil is normally from about 100 to 10,000 ppm expressed as 06 weight of metal (molybdenum) to weight of heavy oil 07 feedstock. Demetalation of the heavy oil to the extent of 08 greater than 30% metals removal can be obtained even with 09 less than 50% conversion of the 1000F+ fraction when the catalyst concentration is in this range, and surprisingly, 11 even when the catalyst concentration is less than about 12 500 ppm, or even 200 ppm. If the 1000r+ conversion of the 13 heavy oil is less than 70% the coke yield can be maintained 14 at less than about 1%, and surprisingly, even at conversions as high as 90% and at low slurry catalyst concentrations 16 (100-1000 ppm) the coke yield can be maintained at less than 17 about 2.5 percent.

19 The process conditions for the second-stage or fixed bed reactor are typical of heavy oil desulfurization conditions 21 except that the preferred flow regime is preferably 22 cocurrent up-flow to minimize the build-up of solids in the 23 bed. The second-stage reactor may be either a fixed, 24 ebullated or a moving bed reactor. The catalyst used in the second stage reactor is a hydrodesulfurization-demetalation 26 catalyst such as those containing a Group VI and/or a 27 Group VIII metal deposited on a refractory metal oxide.
28 Examples of such catalysts are described in U.S.
29 Patents 4,456,701 and 4,466,574 incorporated herein by reference. The process conditions for typical one- and 31 two-stage operations are listed in Table VII.

w 's ~

04 Reactor: Thermal Coil Bubble Up-Flow 05 or Ebullated Bed 06 Flow Regime: Bubble to Dispersed -------Conditions (typical) 07 Catalyst to Oil 08 Metal wt, percent: <------about 0.01 to about 10------>
Temperature: 750 - 1000F 750 - 875F
09 Pressure Total: <------- 500 to 4500 psig ------->
H2 Pressure: <------- 200 to 4500 psi. ------->
11 Recycle Gas Rate: 500 - 2500 SCFB 1500 - 15000 SCF~
12 LHSV, Vol/Hr/Vol: --- 0.10 - 6.0 l/Hr Coil Volume 0.005 - 0.045 ----------------------13 Cu.Ft/Bbl./Day:

FIXED_BED HYDROPROCESSING STAGE

17 Flow Regime: Preferably Up-flow Conditions (typical) 18 Temperature: 625 - 810F

Total Pressure: 1500 - 4500 psig H2 Pressure: 1000 - 4500 psi.

22 Recycle Gas Rate: 1500 - 15000 SCFB
23 LHSV,Vol/Hr/Vol: 0.10 - 2.0 1/Hr Active vs. Inactive Slurry Catalysts:

28 Quantities of coke greater than 2.5 weight percent based on 29 fresh feed are often formed durinq thermal treatment of heavy oils. This coke can be held up in fixed bed reactors 31 causing an undesirable increase in the pressure drop across 32 the reactor, loss of catalytic activity and eventually 33 leading to reactor shut down. It is therefore desirable to 34 minimize the formation of coke in the fixed bed catalytic ~J ~ J

01 hydroprocessing reactor as well as in any thermal 02 pretreatment which takes place prior to that stage.

04 The use of the active catalyst slurry of the present process 05 in the thermal pretreatment stage results in a significant 06 reduction in coke formation compared to pretreatment using 07 other relatively inactive slurry catalysts, such as ammonium 08 heptamolybdate. This is illustrated in the comparative 09 examples of Table VIII. In Table VIII TCHC signifies a run made by the thermal catalytic hydroconversion (TCHC) process 11 using a slurry catalyst which is the relatively inactive 12 ammonium heptamolybdate. In Table VIII, the process run 13 labeled ACTIVE corresponds to the use of the active catalyst 14 slurry of the present invention. In the thermal catalytic hydroconversion process (TCHC Table VIII) the relatively 16 inactive slurry catalyst was an aqueous ammonium 17 heptamolybdate mixed with a succinimide surfactant. The 18 reactor used for the active process was a stirred autoclave 19 having a length to diameter ratio of 2.6. The (TCHC) thermal catalytic hydroconversion studies were performed in 21 an unstirred reactor having a length to diameter ratio of 22 20. The Maya feedstocks used in both studies were virtually 23 identical with the possible exception of a small difference 24 in the 1000F+ content. When Maya vacuum residuum is processed using the thermal catalytic hydroconversion 26 process (TCHC) (e.g., USP 4,564,439; USP 4,761,220;
27 USP 4,389,301), in a one-stage process which uses the 2~ comparatively inactive slurry catalyst, a coke yield of 4.5%
29 is observed at 85~ convcrsion of 1000F+. When the active catalyst slurry of the present process is substituted for 31 this relatively inactive catalyst, a coke yield of only 1.6%
32 is observed at 88% conversion of 1000F+ fraction.

~,i a'~.~,..i 01 This reduction in coke yield is observed over a wide ranqe 02 of concentrations of slurry catalysts and thermal severities 03 as illustrated in Figure 6. In Figure 6 coke yields for the 04 process of the present invention and the TCHC process are 05 compared over a wide range of thermal severities as 06 indicated by 1000F+ conversion. The coke yield for the 07 active slurry catalyst of the present processes is much less 08 than that for the relatively inactive TCHC processing.

TABLE VIII
11 Comparison of Products Produced via Slurry Hydroprocessing 12 Using Active or Inactive (TCHC) Slurry Catalysts 13 Run Identification ACTIVE TCHC
Feed Properties 14 Feed Stock Maya 900F+Maya 975F+
Carbon wt. % 83.73 83.89 ~6 Hydrogen wt. % 9.83 9.85 Nitrogen ppm 7000 6900 17 Sulfur wt. ~ 4.99 5.15 18 Nickel ppm 118 112 Vanadium ppm 590 600 Run Conditions Temperature F 836 835 21 Pressure psig 2402 2400 22 Gas Recycle scf/bbl7052 6500 LHSV vol/hr/vol0.10 0.39 24 Slurry Catalyst Catalyst Conc.
as ppm Mo ppm 1000 1000 26 Nickel Conc. ppm 100 0 27 ~ydrogen Consumption scf/bbl 1949 1500 Chemical Conversions From Oil 28 1000+ vol ~ 88 85 29 Nitrogen wt. % 54 25 Sulfur wt. % 80 70 Nickel wt. % 96 89 31 Vanadium wt. ~ 99 97 32 Coke Yield wt. % 1.6 4.5 ^t .71 ~

01 Among other advantages, Table VIII shows the capability of 02 the process of the present invention to remove metals from 03 heavy oils more efficaciously than the other process. The 04 advantage in this superior metals removal is improved 05 operations of the catalytic hydroprocessing second-stage due 06 to increased catalyst life. Also the demetalation is 07 realized at lower thermal severity and consequently lower 08 destabilization of the feed prior to catalytic 09 hydroprocessing.

11 Figure 7 illustrates clearly the difference between the 12 present process and the thermal catalytic hydroconversion 13 process. Figure 7 illustrates that the active catalyst 14 process of the present invention provides demetalation at lower levels of conversion than the inactive slurry catalyst 16 process. Lower conversion leads to lower destabilization of 17 the feed prior to catalytic hydroprocessing. The less 18 severe the thermal treatment of the feed the more stable are 19 the products obtained.

21 Active Slurry Catalysts In Resid Hydroprocessinq:

23 Catalyst life in fixed bed or ebullating bed resid 24 hydroprocessing units is limited by metals or coke deposited on the catalyst. The deposited metals and coke plug the 26 catalyst pores and decrease the catalyst activity for 27 hydrogenation, desulfurization and carbon residue removal.
2B Thus, the life of these catalysts can be increased by 29 removing a portion of the metals and coke precursors. The demetalation and coke precursor removal can be achieved with 31 an active slurry catalyst in which some of the metals are 32 deposited on said slurry catalyst prior to contacting the 33 heavy feed with the fixed bed or ebullating bed catalyst.

34 Alternatively the demetalation can be achieved by the slurry 01 catalyst within the fixed bed or ebullating bed 02 hydroprocessing unit.

06 The following example illustrates the advantage of 07 pretreating a high metals content heavy feed with an active 0~ slurry catalyst prior to feeding the residuum to a fixed bed 09 hydroprocessing unit. The feedstock was an Arabian Heavy atmospheric resid having the inspections listed in 11 Table IX. ~able X lists the operating conditions and 12 results when processing this feed containing an active 13 slurry catalyst in a slurry reactor and in a two-stage 14 system consisting of a slurry reactor followed by an upflow fixed bed reactor. For comparison purposes, the results 16 obtained for processing the feed in a fixed bed reactor 17 without the slurry catalyst are also included.

19 The slurry catalyst was prepared by sulfiding an aqueous ammonium molybdate solution containing 12 weight percent 21 molybdenum and an ammonia to molybdenum weight ratio. The 22 solution was sulfided at 150F and 400 psig with a 23 hydrogen-hydrogen sulfide gas mixture equal to 13.5 standard 24 cubic feet of hydrogen sulfide per pound of molybdenum.
Nickel sulfate solution was added to the resulting slurry to 26 give a 0.1 nickel to molybdenum weight ratio. The slurry 27 catalyst was dispersed into the feed oil at a 200 ppm level 2~ based upon the weight of molybdenum.

For both tests, the fixed bed reactors were charged with a 31 graded catalyst system: 16.7 volume percent of Catalyst A
32 containing 1.5% cobalt, 6% molybdenum, and 0.8% phosphorous 33 on alumina; 16.7 volume percent of Catalyst 8 containing 34 1~ cobalt, 3% molybdenum, and 0.4% phosphorous on alumina;

01 and 66.6% volume percent of Catalyst C containing 3% nickel, 02 8% molybdenum and 1.8% phosphorous on alumina. The flow 03 direction was upflow with Catalyst A placed at the bottom of 04 the reactor. Catalyst B was placed above Catalyst A, and 05 Catalyst C was placed above Catalyst B. Prior to use, the 06 catalysts were sulfided. The slurry reactor was a one-liter 07 autoclave equipped with a turbine to insure good mixing 08 between the liquid, gas, and catalyst. Flow of the gas, 09 oil, and catalyst was upward.

11 As can be seen in this example, the performance of the fixed 12 bed unit is improved when coupled with a slurry reactor.
13 The crackinq conversion and the carbon residue conversion 14 are markedly increased, thus resulting in more valuable products. Since a significant amount of nickel and vanadium 16 were deposited on the active catalyst in the slurry reactor, 17 the life of the fixed bed catalyst would be increased 18 because of reduced amounts of metals being deposited.

One efficient method to increase the yield of distillate is 21 to feed the heavy uncracked product from a hydroprocessing 22 step to a delayed coker or fluid coker. In these processes, 23 the heavy feed is cracked to light gases, distillates, and 24 coke. Because the distillate products generally are more valuable than coke, it is desirable to minimize the amount 26 f Coke.

28 If the 1000F~ products from the above examples were sent to 29 a delayed coker, the coke yield can be reduced by pretreating the feed using the active slurry catalyst prior 31 to hydroprocessing in a fixed bed unit. Fixed bed 32 hydroprocessing without the slurry catalyst pretreatment 33 resulted in a 1000F+ product of 41.4 volume percent. With 34 the active slurry catalyst, a yield of only 21.5 volume 01 percent was obtained. These products contained 15.2% and 02 20.2% Conradson Carbon, respectively. Thus, the delayed 03 coke yields from these 1000F+ products would be 10.1 weight 04 percent and 6.9 weiqht percent, respectively, calculated on 05 a basis of fresh feed to the hydroprocessing unit. The 06 reduction in coke yield due to the pretreatment with the 07 active slurry catalyst is thus 31%.

11 Arab Heavy Feed Atmos. Resid Nitrogen ppm 2824 13 Sulfur wt.% 4.5 15 Material boiling above lOOOFvol% 55 API Gravity API 11.3 16 Micro Carbon Residue wt.% 14.4 17 Carbon wt.% 84.38 18 ~ydrogen wt.% 10.82 19 Nickel ppm 27 20 Vanadium ppm 100 21 Iron ppm 3 X ~ o I I ~ O c~ ~ ~ ~ ~ ~ ~ ~ ~ ~o ~ u~ o o z I I o ~ ~ ~ ~ ~:r o u~ X u~ t~ a~

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Claims (36)

WHAT IS CLAIMED IS:

1. A process for preparing a dispersed Group VIB metal sulfide catalyst for hydrocarbon oil hydroprocessing comprises:

(a) sulfiding an aqueous mixture of a Group VIB metal compound, with a gas containing hydrogen sulfide to a dosage greater than about 8 SCF of hydrogen sulfide per pound of Group VIB metal, to form a slurry; and (b) mixing said slurry with feed oil and a hydrogen-containing gas at elevated temperature and pressure.

2. A process according to Claim 1 wherein said hydrogen sulfide dosage is about 8-14 SCF of hydrogen sulfide per pound of Group VIB metal.

3. A process according to Claim 1 wherein said Group VIB
metal is an oxide.

4. A process according to Claim 1 wherein said Group VIB
metal is molybdenum.

5. A process according to Claim 1 wherein said Group VIB
metal compound is molybdenum oxide.

6. A process according to Claim 1 wherein said Group VIB
metal compound is an ammoniated salt.

7. A process according to Claim 1 wherein said Group VIB
metal compound is an ammonium molybdate.

8. A process according to Claim 1 wherein said Group VIB
metal compound aqueous mixture is obtained by treating a Group VIB metal oxide with aqueous ammonia.

9. A process according to Claim 1 wherein said Group VIB
metal compound aqueous mixture is obtained by treating molybdenum oxide with aqueous ammonia.

10. A process according to Claim 1 wherein said elevated temperature is at least about 350° F.

11. A process according to Claim 1 wherein prior to mixing with feed oil, said slurry is in the incipient gel stage.

12. A process according to Claim 1 wherein said sulfiding is performed with a gas containing a partial pressure of hydrogen and the dosage of hydrogen sulfide is in the range of about 12 to 14 SCF of hydrogen sulfide per pound of Group VI B metal.

13. A process according to Claim 1 wherein said sulfiding is performed in the absence of hydrogen and the dosage of hydrogen sulfide is in the range of about 8 to 10 SCF of hydrogen sulfide per pound of Group VIB
metal.

14. A process for preparing a dispersed Group VIB metal sulfide catalyst for hydrocarbon oil hydroprocessing comprises:

(a) sulfiding an aqueous mixture of a Group VIB metal compound, with a gas containing hydrogen sulfide, to a dosage of about 8-14 SCF of hydrogen sulfide per pound of Group VIB metal, to form a slurry;

(b) adding a Group VIII metal compound to said slurry;
and (c) mixing said slurry and Group VIII metal compound with a feed oil and a hydrogen-containing gas at elevated temperature and pressure.

15. A process according to Claim 14 wherein said slurry is at the incipient gel formation stage.

16. A process according to Claim 14 wherein said Group VIII
metal compound is added to said slurry at a slurry pH
less than about 8.

17. A process according to Claim 14 wherein said Group VIII
metal to Group VIB metal weight ratio is about 1:2 to about 1:100.

18. A process according to Claim 14 wherein said Group VIB
metal is molybdenum.

19. A process according to Claim 14, 15, 16, 17 or 18 wherein said Group VIII metal is nickel.

20. A process according to Claim 14 wherein said Group VIII
metal compound is a sulfate, nitrate or carbonate.

21. A process according to Claim 14, 15, 16, 17 or 18 wherein said Group VIII metal is cobalt.

22. A process of hydroprocessing a heavy hydrocarbonaceous feedstock comprises contacting said feedstock with the catalyst of Claim 1 in the presence of hydrogen at elevated temperature and pressure.

23. A process for the production of a high viscosity index lubricating oil from a heavy oil comprises the steps of:
(a) sulfiding an aqueous mixture of a Group VIB metal compound with a gas containing hydrogen sulfide to a dosage of greater than 8 SCF of hydrogen sulfide per pound of Group VIB metal;

(b) contacting the product of step (a) with a heavy oil feedstock and a hydrogen-containing gas at elevated temperature and pressure, and at a concentration of 0.01 wt.%, or greater, of Group VIB metal based on the weight of said feedstock to form a product;

(c) separating from the product of step (b) a fraction boiling above about 650°F: and (d) dewaxing said fraction to produce said lubricating oil.

24. A process according to Claim 23 wherein said heavy oil feedstock is contacted with the product of step (a) at a temperature of about 775°F, or greater, and at a hydrogen partial pressure of about 700-4500 psi.

25. The product in the lubricating oil range boiling range produced according to Claim 23 is hydrotreated prior to catalytic dewaxing.

26. A process for the production of a high viscosity index lubricating oil from a heavy oil comprises the steps of:

(a) sulfiding an aqueous mixture of a Group VIB metal compound with a gas containing hydrogen sulfide to a dosage of greater than 8 SCF of hydrogen sulfide per pound of Group VIB metal;

(b) adding a Group VIII metal compound to the product of step (a);

(c) contacting the product of step (b) with a heavy oil feedstock and a hydrogen-containing gas at elevated temperature and pressure and at a concentration of 0.01 wt.%, or greater, of Group VIB metal based on the weight of said feedstock, to form a product;

(d) separating from the product of step (c) a fraction boiling above about 650°F; and (e) dewaxing said fraction to produce a lubricating oil.

27. A process according to Claim 26 wherein the product of step (a) is in the incipient gel formation stage.

28. A process for the hydroprocessing of heavy hydrocarbonaceous oil containing metal contaminants comprises introducing said oil, an active catalyst slurry and a hydrogen-containing gas at elevated temperature and pressure into a fixed or ebullating bed of hydrodesulfurization-hydrodemetalation catalyst at temperatures greater than about 700°F:

wherein said active catalyst slurry is prepared by sulfiding an aqueous mixture of a Group VIB metal compound with a gas containing hydrogen sulfide to a dosage greater than 8 SCF of hydrogen sulfide per pound of Group VIB metal.

29. A process for the hydroprocessing of heavy hydrocarbonaceous oil containing metal contaminants comprises introducing said oil, an active catalyst slurry, porous contact particles, and a hydrogen-containing gas at elevated temperatures and pressures into in a fixed or ebullating bed of hydrodesulfurization-hydrodemetalation catalyst at temperatures greater than about 700°F:

wherein said active catalyst slurry is prepared by sulfiding an aqueous mixture of a Group VIB metal compound with a gas containing hydrogen sulfide to a dosage greater than 8 SCF of hydrogen sulfide per pound of Group VIB metal.

30. A process for the hydroprocessing of heavy hydrocarbonaceous oil containing metal contaminants comprises:

(a) contacting said oil in a first stage with an active catalyst slurry and hydrogen at a temperature and for a time sufficient to achieve measurable thermal cracking in the product stream;
and (b) in a second stage, contacting said product stream with hydrogen in a fixed or ebullating bed of hydrodesulfurization-hydrodemetalation catalyst at temperatures greater than about 700°F:

wherein said active catalyst slurry is prepared by sulfiding an aqueous mixture of a Group VIB metal compound with a gas containing hydrogen sulfide to a dosage greater than about 8 SCF of hydrogen sulfide per pound of Group VIB metal.

31. A process according to Claim 28, 29 or 30 wherein the oil flow is upward through said fixed bed.

32. A process according to Claim 28, 29 or 30 wherein the 1000°F+ fraction conversion of said heavy oil is less than 50%, the percent demetalation of nickel or vanadium is greater than 30%, and the slurry catalyst concentration is about 100-10,000 ppm in said heavy oil.

33. A process according to claim 28, 29 or 30 wherein the 1000°F+ fraction conversion of said heavy oil is greater than 50% and the coke yield is less than about 2.5% at a slurry catalyst concentration of about 100-10,000 ppm in said heavy oil.

34. A process according to Claim 31 or 32 wherein the slurry catalyst concentration is less than about 500 ppm.

35. A process according to Claim 31 or 32 wherein the slurry catalyst concentration is less than about 200 ppm.

36. A process according to Claim 28, 29 or 30 wherein to said slurry is added a Group VIII metal compound.