FIELD

This application relates to bulk catalyst compositions, methods of making these bulk catalyst compositions, and use of bulk catalyst compositions for hydroprocessing of a hydrocarbon feedstock, which can include hydrodesulfurization and/or hydrodenitrogenation.

BACKGROUND OF THE INVENTION

Increasing environmental regulations have been enacted mandating lower levels of sulfur in transportation and other fuel products in order to combat the atmospheric discharge of sulfur compounds during processing and end-use of petroleum products on the basis of the health and environmental problems it may pose. For instance, European regulations have required a change in the content of sulfur from 5000 ppm in low sulfur diesel to less than 10 ppm in ultra-low sulfur diesel (ULSD).

Hydroprocessing involves the treatment of hydrocarbons with hydrogen in the presence of catalysts, and is a conventional method for heteroatom (e.g., sulfur and nitrogen) removal. Many existing hydroprocessing facilities, such as those using relatively low pressure hydrotreaters, were constructed before these more stringent sulfur reduction requirements were enacted and represent a substantial prior investment. Upgrading of these existing hydrotreating reactors presents a variety of fiscal and logistical difficulties. Hydrotreaters constrained to operate at low hydrogen partial pressure and with limited hydrogen availability may require large amounts of catalysts to lower the sulfur content and meet regulations or downstream process. As such, refineries are often operating at the top of their capacity, both with respect to temperature and pressure.

Additionally, such refineries may process feeds containing hindered sulfur and nitrogen within multi-ring aromatics. For these feeds, processes such as hydrodesulfurization (HDS) or hydrodenitrogenation (HDN) may be used where hydrogenation is followed by hydrogenolysis before sulfur or nitrogen removal. However, these processes require high pressures, whereas the direct sulfur removal mechanism (direct desulfurization or DDS) is a single step reaction in which sulfur is converted via C-S bond cleavage without ring saturation and removes S in the form of H2S. This mechanism is not as sensitive to hydrogen partial pressure and may be used at lower pressures, with a low treat gas ratio, but is prone to H2S poisoning of the catalyst. Thus, these units are limited in the amount of and quality of feed that can be processed.

The large-volume low-pressure hydroprocessing business model described above makes commercializing high-cost, high-weight catalysts highly challenging. Consequently, a need exists for low-cost catalysts with improved activity characteristics that can support low-pressure hydroprocessing without the same H2S poisoning difficulties.

Conventional approaches to bulk bimetal hydroprocessing catalysts suggest that tungsten addition improves activity. See, e.g., U.S. 7,288,182 (“Bulk multimetal hydroprocessing catalysts containing non-noble group VIII and group VIB metal oxides” at Table 9) and U.S. 2007/0090024 (“Hydroprocessing using bulk bimetallic catalysts” at Table 7). See also, U.S. 6,162,350 (“Hydroprocessing using bulk group VIII/Group VIB catalysts”), U.S. 2007/0084754 (“Bulk bimetallic catalysis, method of making bulk bimetallic catalysts and hydroprocessing using bulk bimetallic catalysts”), and U.S. 2002/0010088 (“Process for preparing a mixed metal catalyst composition”).

U.S. Patent 7,951,746 describes bulk Group VIII / Group VIB metal catalyst precursors that also include carbon, as well as corresponding catalysts. During synthesis of the catalyst precursor, an organic acid is included in the synthesis mixture. After a heating step, at least a portion of the carbon from the organic acid is retained in the bulk catalyst precursor. The precursor can then be sulfided to form a catalyst. Due to the presence of roughly 10 wt% to 25 wt% of carbon in the catalyst precursor, the weight of Group VIII and Group VIB metals in the catalyst can be 60 wt% or less. The balance of the catalyst precursor weight is oxygen, as the metals in the precursor are present in the form of metal oxides.

International Patent Application Publication WO/2012/059523 describes bulk Group VIII / Group VIB catalyst precursors and catalysts. The catalyst precursors are formed by combining metal reagents in a solvent under supercritical conditions.

SUMMARY OF THE INVENTION

This application relates to bulk catalyst compositions, methods of making these bulk catalyst compositions, and use of bulk catalyst compositions for hydroprocessing of a hydrocarbon feedstock, which can include hydrodesulfurization and/or hydrodenitrogenation.

In an aspect, a catalyst precursor composition is provided. The composition includes cobalt oxide and molybdenum oxide, a molar ratio of cobalt to molybdenum in the catalyst precursor composition being between 1.5 and 4.0. The composition can have an X-ray powder diffraction pattern comprising characteristic diffraction peaks having d-spacing values of a) about O O O O O

3.19 A, 2.67 A, and 1.57 A, b) about 2.67 A and 1.57 A, and a bump feature at a 20 value between 20° and 30° in the X-ray powder diffraction pattern, c) about 3.32 A, 3.03 A, and 2.64 A, or d) a combination of two or more of a), b) and c). In some aspects, the catalyst precursor composition can have a stoichiometry of CO _X MOO _3+X - y(H2O) wherein 1.5 < x < 4.0 and 0 < y < 2.0. In some aspects, the catalyst precursor composition can have a surface area between 50 m ² /g and 190 m ² /g, or 75 m ² /g to 175 m ² /g.

It is noted that the bump feature at a 20 value between 20° and 30° in the X-ray powder diffraction pattern is believed to correspond to a disordered structure.

In some additional aspects, a sulfided catalyst can be formed by sulfiding a catalyst precursor composition. Methods of forming a catalyst precursor composition, such as by reacting CoCOa and MoOa, are also provided.

BRIEF DESCRIPTION OF THE DRAWING

The following figures are included to illustrate certain aspects of the present disclosure, and should not be viewed as exclusive configurations. The subject matter disclosed is capable of considerable modifications, alterations, combinations, and equivalents in form and function, as will occur to one of ordinary skill in the art and having the benefit of this disclosure.

FIG. 1 shows the X-ray diffraction patterns for a Co2MoO _x catalyst precursor composition according to the present disclosure.

FIG. 2 shows the X-ray diffraction patterns for a Co2MoO _x catalyst precursor composition according to the present disclosure.

FIG. 3 shows the X-ray diffraction patterns for a C02M0.5W.5 catalyst precursor composition.

FIG. 4 shows the X-ray diffraction patterns for a COI.2MOO _X catalyst precursor composition.

FIG. 5 shows the X-ray diffraction patterns for two COI.2MOO _X products according to the present disclosure.

FIG. 6 shows the X-ray diffraction patterns for a Co2VO _x catalyst precursor composition.

FIG. 7 shows X-ray diffraction patterns for catalyst precursor compositions including varying ratios of Co to Mo.

FIG. 8 shows X-ray diffraction patterns for catalyst precursor compositions formed using various reaction times and reaction temperatures.

FIG. 9 shows X-ray diffraction patterns of catalyst precursor compositions formed using various metal precursor reagents. DET AILED DESCRIPTION OF THE INVENTION

This application relates to bulk catalyst compositions, methods of making these bulk catalyst compositions, and use of bulk catalyst compositions for hydroprocessing of a hydrocarbon feedstock, which can include hydrodesulfurization and/or hydrodenitrogenation.

DEFINITIONS

All numerical values within the detailed description and the claims herein are modified by “about” or “approximately” with respect to the indicated value, and take into account experimental error and variations that would be expected by a person having ordinary skill in the art. Unless otherwise indicated, room temperature is about 25 °C.

As used in the present disclosure and claims, the singular forms “a,” “an,” and “the” include plural forms unless the context clearly dictates otherwise.

The term “and/or” as used in a phrase such as “A and/or B” herein is intended to include “A and B,” “A or B,” “A”, and “B.”

As used here, the term “bulk catalyst composition” includes catalyst compositions formed through precipitation and/or solid-solid reactions. In some embodiments, the bulk catalyst composition can be free of binder additives (“unsupported”), or composited with a binder to aid formulation of the materials into particles, such as for fixed bed applications. Bulk catalyst compositions disclosed herein can also include dispersing-type catalyst (“slurry catalyst”) for use as dispersed catalyst particles in mixture of liquid (e.g., hydrocarbon oil), which similarly can be formulated with or without a binder.

Binders for bulk catalyst compositions include any suitable binder for hydroprocessing applications, such as silica, silica-alumina, alumina such as (pseudo)boehmite, gibbsite, titania, zirconia, cationic clays or anionic clays such as bentonite, kaoline, sepiolite or hydrotalcite, or mixtures thereof. Preferred binders are silica, silica-alumina, alumina, titanic, zirconia, or mixtures thereof. Binders can also include binder precursors such as alkali metal aluminates (to obtain an alumina binder), water glass (to obtain a silica binder), a mixture of alkali metal aluminates and water glass (to obtain a silica alumina binder), a mixture of sources of a di-, tri-, and/or tetravalent metal such as a mixture of water-soluble salts of magnesium, aluminum and/or silicon (to prepare a cationic clay and/or anionic clay), chlorohydrol, aluminum sulfate, or mixtures thereof. Binders can be added to a bulk catalyst composition in amounts from 0-95 wt. % of the total composition, depending on the envisaged catalytic application.

The terms “treatment,” “treated,” “upgrade”, “upgrading” and “upgraded”, when used in conjunction with a heavy oil feedstock, describes a heavy oil feedstock that is being or has been subjected to hydroprocessing, or a resulting material or crude product, having a reduction in the molecular weight of the heavy oil feedstock, a reduction in the boiling point range of the heavy oil feedstock, a reduction in the concentration of asphaltenes, a reduction in the concentration of hydrocarbon free radicals, and/or a reduction in the quantity of impurities, such as sulfur, nitrogen, oxygen, halides, and metals.

The upgrade or treatment of heavy oil feeds is generally referred herein as “hydroprocessing” (or hydroconversion). Hydroprocessing means any oil feed upgrading or treatment process carried out in the presence of hydrogen, including, but not limited to, hydroconversion, hydrocracking, hydrogenation, hydrotreating, hydrodesulfurization, hydrodenitrogenation, hydrodemetallation, hydrodearomatization, hydroisomerization, hydrodewaxing, and hydrocracking, including selective hydrocracking. The products of hydroprocessing may show improved viscosities, viscosity indices, saturates content, low temperature properties, volatilities and depolarization, etc.

As used herein, the term “catalyst precursor” refers to a compound containing one or more catalytically active metals, from which compound the catalyst of the inventive catalyst comprising cobalt and molybdenum is eventually formed, and which compound may be catalytically active as a hydroprocessing catalyst.

As used herein, the phrase “one or more of’ or “at least one of’ when used to preface several elements or classes of elements such as X, Y and Z or Xi-X _n , Y i-Y _n and Zi-Z _n , is intended to refer to a single element selected from X or Y or Z, a combination of elements selected from the same common class (such as Xi and X2), as well as a combination of elements selected from different classes (such as Xi, Y2and Z _n ).

Bulk

In various aspects, it has been discovered that novel bulk catalyst precursor compositions can be formed based on cobalt oxide and molybdenum oxide. The sulfided forms of the novel bulk catalyst precursor compositions can provide unexpectedly high activity relative to the volume and/or weight of the catalyst I catalyst precursor. Without being bound by any particular theory, it is believed that the unexpectedly high activity is due in part to an unexpectedly high molar ratio of Co relative to Mo in the catalyst precursor I the sulfided catalyst. Additionally or alternately, it is believed that the unexpectedly high activity is due in part to an unexpectedly high surface area for the catalyst precursor composition.

In some aspects, catalyst precursor compositions described herein can have an X- ray powder diffraction pattern comprising characteristic diffraction peaks having first set of d- spacing values of about 3.19 A, 2.67 A, and 1.57 A. It is noted that the peak corresponding to a d- spacing value of 3.19 A corresponds to a peak at a 20 value between 20° and 30° in the X-ray powder diffraction pattern. Without being bound by any particular theory, it is believed that the catalyst precursor composition can have an at least partially disordered structure in the crystal direction corresponding to the d-spacing value of 3.19 A. As a result, in some aspects, instead of and/or in addition to having peak at a d-spacing value at 3.19 A, the X-ray powder diffraction pattern can include a broader spectral feature corresponding to a bump in the pattern. This bump can be present at a 20 value between 20° and 30° in the X-ray powder diffraction pattern. As detailed below, as long as the d-spacing values of 2.67 A and 1.57 A are present, the beneficial catalyst activity provided by catalysts formed from such a structure is maintained when a peak is present at a d-spacing value of 3.19 A, or when a bump feature is present between 20° and 30°, or when both a peak at 3.19 A and a bump between 20° and 30° are present.

In other aspects, catalyst precursor compositions described herein can have an X- ray powder diffraction pattern comprising characteristic diffraction peaks having a second set of d-spacing values of about 3.32 A, 3.03 A, and 2.64 A. This catalyst precursor composition does not appear to be susceptible to having disorder along any of the crystallographic directions, so this catalyst precursor composition is indicated by the presence of all three of the d-spacing values.

In still other aspects, catalyst precursor compositions described herein can correspond to a mixture of the composition having the first set of d-spacing values and the composition having the second set of d-spacing values. In such aspects, a catalyst composition can have an X-ray powder diffraction pattern comprising characteristic diffraction peaks having a third set of d-spacing values of about 3.32 A, 3.03 A, 2.67 A, 2.64 A, 1.57 A, and at least one of a d- spacing value of 3.19 A and a bump at a 20 value between 20° and 30° in the X-ray powder diffraction pattern.

In various aspects, a catalyst precursor composition having the first set of d-spacing values, the second set of d-spacing values, or the third set of d-spacing values can correspond to a precursor composition that includes an unexpectedly high ratio of Co to Mo. In such aspects, the bulk catalyst precursor compositions can have a stoichiometry of Co _x MoO3+x, where 1.5 < x < 4.0. Optionally, waters of hydration can also be included in the catalyst precursor composition. For example, the composition can optionally include 0 to 2 molar equivalents of waters of hydration, so that the stoichiometry of the catalyst precursor composition, including waters of hydration, can be CO _X MOO _3+X - y(H2O), where y is between 0 to 2. In some aspects, a catalyst precursor composition can have a surface area between 50 m ² /g and 190 m ² /g, as measured by Brunauer-Ernett-Teller method, or BET. It is noted that the stoichiometry of the catalyst precursor composition may not match the stoichiometry of the corresponding sulfided catalyst. For example, for a catalyst precursor composition having a molar ratio of Co to Mo of 2 : 1, sulfidation of the catalyst precursor can result in formation of a sulfided catalyst having a Co to Mo ratio of between 1.5 to 2.0.

The catalyst precursor compositions can have an unexpectedly high activity relative to the expected hydroprocessing activity based on conventional understanding of activity for bulk hydroprocessing catalysts. Conventionally, it is understood that for bulk catalysts including Ni as a Group VIII metal, addition of tungsten to a catalyst can provide improved hydroprocessing activity. This can correspond to having a catalyst where the active metals are NiW, or this can correspond to a mixed-metal catalyst where the active metals are NiMoW.

With regard to hydroprocessing catalysts including Co as a Group VIII metal, it is conventionally understood that for supported catalysts, improved hydroprocessing activity can be realized for molar ratios of Co to Mo of 1.0 or less, such as around 0.5.

In contrast to the above conventional understanding, it has been discovered that catalysts with improved activity can be formed by sulfiding bulk catalyst precursors that are based on Co and Mo as catalytic metals, and that have molar ratios of Co to Mo of 1.5 or higher. Without being bound by any particular theory, it is believed that the unexpectedly high hydroprocessing activity is achieved in part by accessing an unexpected crystalline phase for the bulk catalyst precursors, as indicated by the d-spacings for the characteristic peaks in the powder XRD spectra of the bulk catalyst precursors. As evidenced by powder XRD, in some aspects the crystal structure of these unexpected crystalline phases may be similar to the structure of clays. These unexpected crystalline phases are not believed to be available when incorporating tungsten into a catalyst precursor. Thus, in various aspects, the bulk catalyst precursor compositions (and the corresponding sulfided catalysts) can be substantially free of tungsten. Additionally, it is believed that the unexpected crystalline phases are not available when forming bulk catalysts at molar ratios of Co to Mo of 1.0 or less. Thus, in various aspects, the bulk catalyst precursor compositions (and corresponding sulfided catalysts) can have a molar ratio of Co to Mo of between 1.5 to 4.0, or 2.0 to 4.0, or 1.5 to 3.0, or 2.0 to 3.0, or 1.5 to 2.5.

Disclosed bulk catalyst precursor compositions may have a relatively high surface area (measured by Brunauer-Emmett-Teller method, or BET). For example, the bulk catalyst precursor composition may have a surface area of about 50 m ² /g or more, about 75 m ² /g or more, about 100 m ² /g or more, about 125 m ² /g or more, about 150 m ² /g or more, about 175 m ² /g or more, or about 190 m ² /g or more. In any embodiment, the bulk catalyst precursor composition may have surface area (as measured by BET) of at most about 190 m ² /g, at most about 175 m ² /g, or at most about 150 m ² /g. Each of the above lower limits for the bulk catalyst precursor composition surface area is explicitly contemplated to be used in conjunction with each of the above upper limits as boundary limitations.

The catalyst precursor compositions can be synthesized by combining a cobalt- containing precursor reagent with a molybdenum-containing precursor reagent. Cobalt carbonate (CoCO ) and molybdenum oxide (MoO ) are examples of suitable reagents for forming the catalyst precursor composition. The precursor reagents can be dissolved in, for example, water.

The solution of precursor reagents is then heated to a reaction temperature for a reaction time period. The reaction temperature can be between 70°C and 180°C. The reaction time can range from 20 minutes to 24 hours. Higher reactions times and/or higher temperatures can tend to result in formation of the crystalline phase having an XRD pattern with d-spacings of 3.19 A, 2.67 A, and 1.57 A (and/or d-spacing values of 2.67 A and 1.57 A, with a bump at a 20 value between 20° and 30° in the X-ray powder diffraction pattern). For example, heating the reaction mixture to 150°C or more for a reaction time of 6 hours or more can result in a crystalline phase with such an XRD pattern. Shorter reaction times and/or shorter temperatures can tend to result in formation of the crystalline phase having an XRD pattern with d-spacings of 3.32 A, 3.03 A, and 2.64 A. For example, heating to a temperature of 75°C for 30 minutes can result in a crystalline phase with such an XRD pattern. Generally, lower reaction temperature and/or shorter reaction time can result in a catalyst precursor composition with a higher surface area.

Another factor that can provide an increase in surface area is performing an aging step after formation of the catalyst precursor composition but prior to performing sulfidation. An aging step can correspond to maintaining the catalyst precursor composition at a temperature of 50°C to 120°C for a period of 0.5 hours to 48 hours. Optionally, the catalyst precursor composition can be arranged in a manner that increases the external surface area of the composition during aging, such as by spreading the catalyst composition in a thin layer during the aging.

In various aspects, the bulk catalyst composition may also include a binder. For example, after forming catalyst precursor particles that initially include metals, an organic complexing agent, and a silica polymer, suitable binders may be mixed with the precursor composition and extruded to form particles. Examples of suitable binders include, but are not limited to, organo-siloxane polymers as described herein, organo-alumoxane polymers as described herein, organo-titanoxane polymers as described herein, a silica polymer, silica resin, hydrosol, polyethylene glycol, and combinations thereof. Sulfiding processes for treating bulk catalyst compositions disclosed herein can be carried out at a temperature that ranges from about 300°C to about 400°C, about 310°C to about 350°C, or about 315°C to about 345°C. In some embodiments, sulfiding processes can be conducted for a period of time ranging from about 30 minutes to about 96 hours, from about 1 hour to about 48 hours, or from about 4 hours to about 24 hours. As an example, sulfidation can be performed under typical gas phase sulfidation conditions, such as using a mixture of H2S and H2 as a gas flow to provide sulfur during the sulfidation.

Disclosed bulk catalyst compositions may be useful in processes for the hydrodesulfurization and hydrodenitrogenation of feed streams high in sulfur content in a hydrotreating system, including systems requiring low pressures. Hydrocarbon feed streams can include streams obtained or derived from crude petroleum oil, tar sands, coal liquefaction, shale oil, and hydrocarbon synthesis. Hydrocarbon feeds also include feeds boiling from the naphtha boiling range to heavy feedstocks, such as gas oils and resids, and feeds derived from Fischer- Tropsch processes. In some embodiments, hydrocarbon feed streams include streams having a boiling range from about 40°C to about 1000°C. Non-limiting examples of suitable feedstreams include vacuum gas oils; distillates including naphtha, diesel, kerosene, and jet fuel; heavy gas oils, raffinates, lube oils, cycle oils, waxy oils, and the like.

In some cases, hydrocarbon feeds can contain contaminants such as nitrogen and sulfur. Feed nitrogen content based on the weight of the feed can range from about 50 wppm to about 5000 wppm, about 75 wppm to about 800 wppm, or about 100 wppm to about 700 wppm. Nitrogen-based contaminants can appear both as basic and non-basic nitrogen species, and can be free or in an organically-bound form. Examples of basic nitrogen species include quinolines and substituted quinolines, and examples of non-basic nitrogen species may include carbazoles and substituted carbazoles.

Feed sulfur content based on the weight of the feed can range from about 50 wppm to about 7000 wppm, from about 100 wppm to about 5000 wppm, or from about 100 wppm to about 3000 wppm. Feeds subjected to prior processing, such as separation, extraction, hydroprocessing, and the like, may have less sulfur, for example in the range of 75 wppm to 500 wppm.

Feed sulfur can include free or organically-bound sulfur. Organically-bound sulfur can include simple aliphatic, naphthenic, and aromatic mercaptans, sulfides, di- and polysulfides, and heterocyclic sulfur compounds, such as thiophene, tetrahydrothiophene, benzothiophene and their higher homologs and analogs. The feed can also contain olefinic and aromatic hydrocarbon, with aromatic hydrocarbons being present in an amount based on the weight of the feed ranging from about 0.05 wt% to about 50 wt%.

Methods disclosed herein include hydroprocessing a feed by contacting the feed with hydrogen in the presence of the bulk catalyst composition under catalytic hydroprocessing conditions. The term “hydroprocessing” means a catalytic process conducted in the presence of hydrogen, which may be in the form of a hydrogen-containing treat gas. Hydroprocessing processes can include the treatment of various feed streams, such as the hydroconversion of heavy petroleum feedstocks to lower boiling products; the hydrocracking of distillate boiling range feedstocks; the hydrotreating of various petroleum feedstocks to remove heteroatoms, such as sulfur, nitrogen, and oxygen; the hydrogenation of unsaturated hydrocarbon; the hydroisomerization and/or catalytic dewaxing of waxes, such as Fischer-Tropsch waxes; demetallation of heavy hydrocarbons; and ring-opening reactions. “Effective hydroprocessing conditions” can be considered those conditions that achieve the desired result of the hydroprocessing process. For example, effective hydroisomerization and/or catalytic dewaxing conditions are to be considered those conditions that achieve the desired degree of dewaxing to produce the desired product.

Hydroprocessing conditions also include conditions effective for hydrotreating feed streams in some embodiments. Hydrotreating reactions can include, e.g., (i) hydrogenation and/or (ii) hydrogenolysis. Generally, hydrotreating conditions will result in removing at least a portion of the heteroatoms in the feed and hydrogenating at least a portion of the aromatics in the feed.

Methods of hydroprocessing disclosed herein can be performed at temperatures within a range of about 100°C to about 450°C, about 200°C to about 370°C, or about 230°C to about 350°C. Methods of hydroprocessing can be conducted at weight hourly space velocities (“WHSV”) that range from about 0.05 to about 20 hr ^-1 , or about 0.5 to about 5 hr ^-1 . Hydrotreating methods can be performed at any effective pressure, which can include pressures ranging from about 5 to about 250 bar.

Methods of hydroprocessing can utilize hydrogen or a hydrogen-containing treat gas. Treat gas can contain substantially pure hydrogen or can be mixtures of other components typically found in refinery hydrogen streams. In some embodiments, treat gas contains substantially no sulfur-based compounds such as hydrogen sulfide. In some embodiments, treat gas can include at least about 50% by volume hydrogen, at least about 75% by volume hydrogen, or at least about 90% by volume hydrogen. In some embodiments, the hydrogen (H2) to oil ratio can range from about 5 NL/L to about 2000 NL/L. Process conditions may vary, as is known to those skilled in the art, depending on the feed boiling range and speciation. For example, as the boiling point of the feed increases, the severity of the conditions will also increase.

In some embodiments, hydroprocessing reactions occur in a reaction stage that incorporates at least one bulk catalyst composition. The reaction stage can include one or more reactors, or reaction zones that include one or more catalyst beds of the same or different catalyst. Any suitable catalyst bed/reactor can be used, including fixed beds, fluidized beds, ebullating beds, slurry beds, and moving beds. Interstage cooling or heating between reactors, reaction zones, or between catalyst beds in the same reactor, can be employed. A portion of the heat generated during hydroprocessing can be recovered in some embodiments, or conventional cooling to maintain temperature may be performed through cooling utilities such as cooling water or air, or a hydrogen quench stream.

To facilitate a better understanding of the embodiments described herein, the following examples of various representative embodiments are given. In no way should the following examples be read to limit, or to define, the scope of the present disclosure.

EXAMPLES

Standard procedures or customized procedures were followed for bulk catalyst composition preparation, loading, sulfiding, and activity testing. The liquid products were analyzed for nitrogen and sulfur content as low as the <10 ppm wt range using a chemiluminescence analyzer after proper stripping to remove traces of H2S. Catalytic desulfurization activity of the sample catalyst was tested by comparison to a fresh reference catalyst under the same conditions. The test results are reported as Relative Volume Activity (RVA) required to reduce the sulfur level in the liquid product with a constant volume of catalyst tested. MoO _x Catalyst Precursor (Phase 1)

A new structure phase of Co2MoO _x was made by adding 3.006 g of 99.0% grade CoCO and 1.815 g of MoO to 150 ml water. The mixture was heated to 150°C and aged for 6 hours. The product was filtered and spread in a thin layer and dried overnight at 100°C. The process yielded 3.594 g of a brown powder as product, with a very light pink filtrate. The final elemental analysis on solid powder indicated a Co to Mo ratio as C01.62M01. The X-ray diffraction (XRD) spectra for the Co2MoO _x material exhibited d-spacing values of about 3.19 A, 2.67 A, and 1.57 A as shown in FIG. 1.

2: Synthesis of Co2MoO _x Catalyst Precursor (Phase 2) A new phase of Co2MoO _x was made by adding 10.020 g of 99.0% grade CoCO and 6.050 g of MoO to 170 ml water. The mixture was heated to 75°C and aged for 30 minutes. The product was filtered and spread in a thin layer to dry at 100 °C overnight. The final elemental analysis on solid powder indicated Co to Mo ratio as C01.71M01 with a BET surface area analysis of 183.9 m ² /g. The X-ray diffraction (XRD) spectra for the Co2MoO _x material exhibited d-spacing values of about 3.32 A, 3.03 A, and 2.64 A as shown in FIG. 2.

Example 3 - Variations in Molar Ratio of Co to Mo

A method similar to Example 1 was used to make additional catalyst precursor compositions, but with higher molar ratios of Co to Mo in the composition. Instead of using a reaction time of 6 hours and a reaction temperature of 150°C, the compositions were made using a reaction time of 4 hours and a reaction temperature of 100°C. FIG. 7 shows XRD spectra for catalyst precursor compositions made with varying molar ratios of Co to Mo. Line 710 corresponds to the composition from Example 1, where the Co to Mo ratio was near 2 (~1.7). Line 720 corresponds to a composition made with a Co to Mo ratio near 3, while line 730 corresponds to a composition with a Co to Mo ratio near 4. For comparison, a cobalt tungsten catalyst precursor composition (Co to W molar ratio near 4) made in a manner similar to Example 1 is also shown as line 733.

As shown in FIG. 7, lines 710, 720, and 730 show characteristic peaks at d-spacings of 2.67 A and 1.57 A. Line 710 also shows a small peak corresponding to the d-spacing at 3.19 A. However, lines 720 and 730 do not have such a peak. Instead, lines 720 and 730 have a broad bump feature at a 20 value between 20° and 30°. This bump feature is also visible in line 710.

By contrast, the cobalt tungsten catalyst precursor composition (line 733) shows characteristic peaks corresponding to a different type of structure. Line 733 is believed to correspond to a hexagonal phase.

Example 4 - Variations in Reaction Time and Reaction Temperature During Precursor Synthesis

This example demonstrates that by modifying the reaction time and/or reaction temperature used to form a catalyst precursor composition, the resulting surface area of the composition can be modified. In particular, a lower reaction temperature and/or shorter reaction time can be used to produce a higher surface area catalyst precursor composition. After sulfidation, catalyst precursor compositions with higher surface area can provide still higher catalyst activity for desulfurization and/or denitrogenation under hydroprocessing conditions.

The general method of Example 3 was used to make a series of catalyst precursor compositions using various reaction times and reaction temperatures. All of the compositions had a Co to Mo ratio near 2. FIG. 8 shows XRD spectra for the resulting catalyst precursor compositions. Line 835 corresponds to a composition made according to Example 3, with a reaction temperature of 100°C and a reaction time of 4 hours. Line 815 corresponds to a composition made with a reaction temperature of 150°C and a reaction time of 18 hours. Line 825 corresponds to a composition made with a reaction temperature of 100°C and a reaction time of 24 hours. Line 845 corresponds to a composition made with a reaction temperature of 100°C and a reaction time of 1 hour. Line 855 corresponds to a composition made with a reaction temperature of 75 °C and a reaction time of 1 hour.

As shown in FIG. 8, all of the catalyst precursor compositions retained the characteristic peaks at d-spacings of 3.19 A, 2.67 A, and 1.57 A. However, reducing the reaction temperature and/or the reaction time resulted in increasing surface area. The lines in FIG. 8 are shown in order of increasing surface area, starting from the bottom with line 815. The composition corresponding to line 815 had the lowest surface area of 53 m ² /g. The composition corresponding to line 855 had the highest surface of roughly 150 m ² /g.

Example C5 : Synthesis of C02M0.5W.5

A new phase of C02M0.5W.5 was made by adding 10.020 g of 99.0% grade CoCO and 5.041g of MoO , and 10.52g H2WO4 to 170 ml water. The mixture was heated to 75°C and aged for four hours. The product was filtered and spread in a thin layer and dried overnight at 100°C. The final elemental analysis on solid powder indicated Co to Mo to W ratio as C02M0.48W.48 with a BET surface area analysis of 154 m ² /g and a pore volume of 0.40 cc/g. The X-ray diffraction (XRD) spectra for the C02M0.5W.5 material exhibited d-spacing values of about 3.46 A, 2.58 A, and 1.73 A as shown in FIG. 3.

The above synthesis method is similar to the synthesis method used in Example 4 to make the composition corresponding to line 855, although with a longer aging time. Thus, if Co and Mo precursor reagents had been used as in Example 4, a structure with the d-spacings shown in FIG. 1 would be expected. However, as demonstrated by the d-spacing values, replacing half of the Mo with W in the initial synthesis mixture resulted in formation of a different crystalline phase than either Example 1 or Example 2. This demonstrates that the crystalline phases illustrated in FIG. 1 of Example 1 and FIG. 2 of Example 2 cannot be accessed when making a catalyst that includes tungsten.

Example C6: Synthesis of ComMoOx (Ricol phase)

Another Co2MoO _x precursor composition was made by adding 6.012 g of 99.0% grade CoCO3 and 6.050 g of MoO3 to 100 ml water. The mixture was stirred for one day at room temperature, followed by heating to 75°C for 30 minutes. In other embodiments, the mixture was heated to 50°C for four hours. The product was filtered and spread in a thin layer and dried overnight at 100°C. The final elemental analysis on solid powder indicated Co to Mo ratio as C01.2M01.2 with a BET surface area analysis of 72.6 m ² /g and a pore volume of 0.62 cc/g. This new phase exists in a Ricol structure and exhibited the X-ray diffraction (XRD) spectra d-spacing values displayed in FIG. 4. As shown in FIG. 4, using a Co to Mo ratio below 1.5 did not result in formation of the crystalline phase shown in FIG. 2, even though the synthesis method was otherwise substantially the same as the synthesis method used in Example 2. Instead, a Ricol crystalline phase was formed.

The resulting Ricol phase did have a higher surface area than a conventional Ricol phase. For comparison, the new Ricol phase COI.2MOOX material was measured in XRD (line 585) alongside a low surface area (e.g., <15 m ² /g) COI.2MOOX phase (line 591), shown in FIG. 5. Since peak width may be used to estimate to particle size, the six strongest diffractions were selected and compared for changes in full width at half maximum (FWHM) value. As shown in FIG. 5, the novel techniques described herein significantly reduced crystallite size.

Table 1 below illustrates the relationship between a no-aging, low surface area COI. ₂ MOOX phase and a high surface area COI.2MOOX phase prepared with aging according to the disclosed techniques.

Table 1 - Ricol Phase Particle Sizes Based on XRD

Table 1

Example C7: Synthesis of Co2VOx

A new phase of Co2VO _x was made by as made by adding 13.333 g of 99.0% grade CoCO and 5.160 g of V2O5 to 500 ml water. The solution pH was adjusted to 10.1 using diluted NH4OH. The total amount of NH4OH added was 50.11g. The combination was heat refluxed to around 100°C and aged for 4 days. The product was filtered and spread in a thin layer and dried overnight at 100°C. This obtained 13.862 g of brown powder as product, with a filtrate appearing transparent light yellow in color. The product was filtered and spread in a thin layer and dried Co to V ratio as C02.3V1 and BET surface area analysis gives 129.3 m ² /g and a pore volume of 0.32 cc/g. The X-ray diffraction (XRD) spectra for the Co2VO _x material exhibited d-spacing values of about 2.99 A, 2.58 A, and 1.50 A as shown in FIG. 6.

Example C8: Synthesis of CoW

A CoWOx catalyst precursor composition was also synthesized, in order to further illustrate the unexpected nature of the new catalyst precursor composition phases described herein.

The CoWOx composition made by adding 10.02 g of 99.0% grade CoCO and 21.05 g of H2WO4 to 500 ml of water. The combination was heated to 100°C and maintained at that temperature for five days. The combination was then filtered and spread into a thin layer and dried overnight at 100°C. The process obtained 25.297g of a purple powder product with a very light blue filtrate. A final elemental analysis on solid powder indicate Co to W ratio as C01W1.2, and BET analysis gives a surface area of 113 m ² /g.

Example 9 - Comparison of Relative Volume Activities and Relative Weight Activities

To illustrate the benefits of catalysts formed from the catalyst precursor compositions having the novel crystal structures, low pressure hydroprocessing was performed using catalysts formed from the precursor compositions. Several other types of hydroprocessing catalysts were also tested to provide a comparison.

The feed utilized in testing the catalysts under this disclosure had the properties specified in Table 2. This feed is believed to be representative of a straight run diesel feed

Table 2 - Feed Properties Various catalyst precursor compositions were sulfided to form sulfided catalysts. The sulfided catalysts that were tested corresponded to catalysts formed from the CoW catalyst precursor from Example C8; the C02M00.5W0.5 catalyst precursor from Example C5; The C02M0 catalyst precursor from Example 1, referred to herein as having Phase 1; A higher surface area Phase 1 C02M0 catalyst precursor corresponding to line 835 from FIG. 8 (see Example 4); The C02M0 catalyst precursor from Example 2, referred to herein as having Phase 2; A higher bulk catalyst density Phase 2 C02M0 catalyst formed according to the method described below; and a Ricol phase C1.2M0 catalyst made according to Example C6.

Prior to placing the catalyst precursor into the test reactor, the catalyst precursor was formed into particles. The particles had a diameter of roughly 1/16 of an inch. The particles were formed by pressing the catalyst precursor composition powder. For most of the catalyst precursor compositions, the catalyst precursor composition powder was pressed at 15,000 psig (-100 MPa-g) for 3 minutes to form the particles. However, a higher bulk catalyst density Phase 2 C02M0 catalyst precursor composition was formed by pressing the powder at 24,000 psig (-165 MPa-g) for 20 minutes.

The catalyst precursors were sulfided using the following procedure:A charged reactor was pressure-tested with N2, and with H2 at 600 psig (4.1 MPa-g) at 25°C to reach < 1 psi I day (~ < 7 kPa I day) pressure drop. With H2 flowing at 50 cc/min, the temperature was raised to 100 °C. At 100 °C, the pressure was maintained at 100 psig, H2 flow was stopped, and the sulfiding feed (7.5 wt.% of dimethyl disulfide dissolved in a diesel feed) flowing at 8 ml/h was passed over each catalyst for 4 hours for a complete wetting. Then, with the sulfiding feed continuing, H2 was restarted while the temperature increased to 200°C over 1.5 hours, and then to 235°C over 2 hours. The reactor was held isothermal at 235 °C for 16 hours. Following the isothermal hold, the temperature was raised to 290 °C over a period of 10 hours, then raised to 335 °C over 2 hours and held isothermal for 10 hours. The ramp rate and final hold time at temperature were varied up to 1 hr in some runs. These steps completed the sulfiding of the catalyst. The resulting sulfided catalyst was left inside the reactor and then exposed to feedstock without any exposure to air.

After sulfidation, samples of the resulting sulfided catalysts were used to hydroprocess the feedstock in Table 1 under two different types of low pressure hydroprocessing conditions. In a first hydroprocessing condition, the feedstock was exposed to the catalysts at a temperature of 335°C, a pressure of 300 psig (-2.1 MPa-g), a hydrogen treat gas rate of 1000 SCF/bbl (-170 Nm ³ /m ³ ), and a liquid hourly space velocity (LHSV) of 0.5 hr ¹ . In the second hydroprocessing condition, the feedstock was exposed to the catalysts at a temperature of 335°C, a pressure of 600 psig (-4.1 MPa-g), a hydrogen treat gas rate of 1000 SCF/bbl (-170 Nm ³ /m ³ ), and a liquid hourly space velocity (LHSV) of 1.0 hr ¹ .

Table 3 shows results from performing hydroprocessing at the condition including a pressure of -2.1 MPa-g. In Table 3, hydroprocessing activity values are shown for both hydrodesulfurization (HDS) and hydrodenitrogenation (HDN). The order of reaction for HDN is assumed to be 1.0. For HDS, the correct reaction order is less clear, due to the multiple desulfurization mechanisms that can be present. Thus, activity values are shown for values of order of reaction of both 1.3 and 1.5.

To simplify the results, the activity values are shown as relative activity values, either based on weight of the catalyst (RWA) or based on the volume of the catalyst (RVA). In Table 3, the results are normalized based on the activity values for the CoW catalyst.

Table 3 - Low Pressure Hydroprocessing at -2.1 MPa-g As shown in Table 3, the C02M0 catalysts provided higher relative volume activity than the C02M00.5W0.5 catalyst, while providing comparable relative weight activity. This is unexpected, as conventionally it would be expected that catalysts incorporating tungsten would provide superior activity. Additionally, due to the higher cost for catalysts including tungsten, the higher volume activities provided by the C02M0 catalysts represent an activity benefit for a lower cost catalyst.

Table 4 shows the results from hydroprocessing with the same types of catalysts, but at ~4.1 MPa-g and a higher space velocity. Again, the relative activities were normalized based on the activity of the comparative CoW catalyst. Table 4 - Low Pressure Hydroprocessing at ~4.1 MPa-g

As shown in Table 4, the relative activity benefit of the C02M0 catalysts is more pronounced at ~4.1 MPa-g and a space velocity of 1.0 hr ¹ . It is noted that for many types of catalysts, such as the CoW and the C02M00.5W0.5 catalysts, doubling the space velocity while also doubling the pressure would be expected to result in “split” behavior for HDS and HDN. In particular, for many types of catalysts, HDN would be expected to improve based on the increased pressure. However, due to the different types of mechanisms involved in HDS, the activity for sulfur removal can actually decrease under a combination of increased pressure and increased space velocity. By contrast, the C02M0 catalysts shown in Table 3 and Table 4 maintained comparable HDS activity under the increased pressure, increased space velocity conditions while still providing a substantial HDN activity benefit.

Analysis of the low pressure hydroprocessing performance of disclosed Co2MoO _x embodiments displayed an unexpected trend when process conditions changed from 300 psig liquid hourly space velocity (LHSV) 0.5 to 600 psig LHSV 1.0. During such process condition changes, other catalysts show a split of sulfur (S) and nitrogen (N). The split of S and N in these two conditions is expected because N is known to follow indirect hydrogenation route unless subject to significant pressure changes, such as the reactor order to pressure change higher than 1 (e.g., twofold from 300 psig to 600 psig). Doubling the space velocity and doubling the pressure should therefore cause N to drop. S removal, however, is more complicated due to the reaction order to pressure change having two components, HDS and DDS (direct desulfurization). HDS order to pressure should be higher than one but DDS should be lower than one. In the 300 psig region, DDS generally dominates, meaning that when conditions switch S will increase. However, in the analysis, C02M0 showed a lower S at 600 psig LHSV 1.0 condition, thereby indicating a higher HDS function. Upon further scrutiny of S distribution using 2D S-GC, C02M0 displayed a more active DDS component, thereby confirming its potential hydrogen savings in low pressure hydroprocessing via DDS removal of S.

Example 10 - Additional Comparative Catalysts

The synthesis procedure of Example 1 was used to make additional catalyst precursors, but using different starting metal precursor reagents. In one additional example, the Co metal precursor reagent was changed from CoCO to Co3(PO4)2, while maintaining the same overall number of moles of Co. In a second additional example, the Mo metal precursor reagent was changed from MoO3 to MoO2.

FIG. 9 shows XRD patterns of the resulting catalyst precursor compositions. The precursor composition formed from the alternative Co reagent corresponds to line 961, while the precursor composition corresponding to the alternative Mo reagent corresponds to line 971. The sample from FIG. 1 is shown as line 910. As shown in FIG. 9, in addition to having different characteristic peaks, the samples made using the alternative reagents show substantially sharper peaks in the XRD pattern. These sharp peaks are indicative of crystalline phases with low surface areas (possibly less than 1 m ² /g), and therefore phases that are likely to have relatively low catalyst activity. The XRD patterns in FIG. 9 show that formation of the unexpected crystalline phases does not inherently occur simply by combining any combination of metal precursor reagents in the appropriate ratios.

Additional Embodiments

Embodiment 1. A catalyst precursor composition comprising: cobalt oxide; and molybdenum oxide, a molar ratio of cobalt to molybdenum in the catalyst precursor composition being between 1.5 and 4.0, wherein the catalyst precursor composition has an X-ray powder diffraction pattern comprising characteristic diffraction peaks having d-spacing values of a) about

3.19 A, 2.67 A, and 1.57 A, b) about 2.67 A and 1.57 A, and a bump feature at a 20 value between 20° and 30° in the X-ray powder diffraction pattern, c) about 3.32 A, 3.03 A, and 2.64 A, or d) a combination of two or more of a), b) and c).

Embodiment 2. The catalyst precursor composition of Embodiment 1, wherein the catalyst precursor composition has a stoichiometry of Co _x MoOux- y(H2O) wherein 1.5 < x < 4.0 and 0 < y < 2.0.

Embodiment 3. The catalyst precursor composition of any of the above embodiments, wherein the surface area of the catalyst precursor composition is between 50 m ² /g and 190 m ² /g.

Embodiment 4. The catalyst precursor composition of any of the above embodiments, wherein the bump feature at a 20 value between 20° and 30° in the X-ray powder diffraction pattern corresponds to a disordered structure.

Embodiment 5. The catalyst precursor composition of any of the above embodiments, wherein the surface area of the catalyst precursor composition is 75 m ² /g to 175 m ² /g.

Embodiment 6. The catalyst precursor composition of any of the above embodiments, wherein the molar ratio of cobalt to molybdenum in the catalyst precursor composition is between 1.5 and 3.0.

Embodiment 7. A method of making a catalyst precursor composition according to any of Embodiments 1 - 6, the method comprising: combining cobalt carbonate and molybdenum trioxide, and reacting the combination of cobalt carbonate and molybdenum trioxide to form the catalyst precursor composition. Embodiment 8. The method of Embodiment 7, wherein the reacting comprises heating the combination of cobalt carbonate and molybdenum trioxide to at least 75 °C for at least thirty minutes.

Embodiment 9. A sulfided catalyst comprising a sulfided form of the catalyst precursor composition of any of Embodiments 1 - 6 or a sulfided form of the catalyst precursor composition made according to Embodiment 7 or 8.

Embodiment 10. The sulfided catalyst of claim 9, wherein the sulfided catalyst is prepared by combining a first precursor reagent comprising molybdenum and a second precursor reagent comprising cobalt to create a combination; heating the combination to at least 75°C for at least thirty minutes to form the catalyst precursor composition; and sulfiding the catalyst precursor composition, wherein sulfiding comprises raising the temperature of the catalyst precursor composition to about 300°C to about 400°C for a period of time ranging from about 30 minutes to about 96 hours in the presence of a sulfiding compound.

Embodiment 11. The sulfided catalyst of Embodiment 10, wherein the catalyst precursor composition is aged for at least one hour at a temperature below 50°C after the heating of the combination and before the sulfiding.

Embodiment 12. The sulfided catalyst of Embodiment 10 or 11, wherein sulfiding the catalyst precursor composition further comprises heating the catalyst precursor composition to about 150°C for about six hours prior to the raising the temperature to about 300°C to about 400°C.

Embodiment 13. The sulfided catalyst of any of Embodiments 10 to 12, wherein the first precursor reagent comprises CoCO and wherein the second precursor reagent comprises MoO .

All documents described herein are incorporated by reference herein for purposes of all jurisdictions where such practice is allowed, including any priority documents and/or testing procedures to the extent they are not inconsistent with this text. As is apparent from the foregoing general description and the specific embodiments, while forms of the disclosure have been illustrated and described, various modifications can be made without departing from the spirit and scope of the disclosure. Accordingly, it is not intended that the disclosure be limited thereby. For example, the compositions described herein may be free of any component, or composition not expressly recited or disclosed herein. Any method may lack any step not recited or disclosed herein. Likewise, the term “comprising” is considered synonymous with the term “including.” Whenever a method, composition, element or group of elements is preceded with the transitional phrase “comprising,” it is understood that we also contemplate the same composition or group of elements with transitional phrases “consisting essentially of,” “consisting of,” “selected from the group of consisting of,” or “is” preceding the recitation of the composition, element, or elements and vice versa.

Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth used in the present specification and associated claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the embodiments of the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claim, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

Therefore, the present disclosure is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present disclosure may be modified and practiced in different but equivalent manners apparent to one having ordinary skill in the art and having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered, combined, or modified and all such variations are considered within the scope and spirit of the present disclosure. The embodiments illustratively disclosed herein suitably may be practiced in the absence of any element that is not specifically disclosed herein and/or any optional element disclosed herein.