EA043687B1 - RICH FLUIDIZED BED REACTOR USED WITH SUB-QUALITY RAW MATERIALS - Google Patents

Description

BACKGROUND OF THE INVENTION

1. The technical field to which the invention relates.

The present invention relates to heavy oil hydroprocessing systems and methods, such as fluidized bed hydroprocessing systems and methods, that utilize a dual catalyst system to hydroprocess lower quality feedstocks under comparable or more stringent conditions.

2. The technology under consideration.

There is an ever-increasing demand for more efficient use of low-quality heavy petroleum feedstocks and recovery of valuable fuels from them. Low-quality feedstocks are characterized as containing relatively large quantities of hydrocarbons that have a nominal boiling point of 524°C (975°F) or higher. It also contains relatively high concentrations of sulfur, nitrogen and/or metals. The high-boiling fractions generated from these low-quality feedstocks typically have high molecular weight (often measured by higher density and viscosity) and/or a low hydrogen/carbon ratio, which is associated with the presence of high concentrations of undesirable components, including asphaltenes and carbonaceous residue. Asphaltenes and carbonaceous residue are difficult to process and typically cause contamination of conventional catalysts and hydroprocessing equipment because they promote coke formation. In addition, the carbon residue imposes restrictions on the subsequent processing of high-boiling fractions, for example, when they are used as raw material for coking processes.

Examples of lower quality heavy petroleum feedstocks that contain relatively high concentrations of asphaltenes, carbonaceous residue, sulfur, nitrogen and metals include heavy crude oil, oil sands bitumen, and residue from conventional petroleum refining processes. The expression residue (or bottoms) can refer to atmospheric column bottoms and vacuum column bottoms. The bottoms of the atmospheric column may have a boiling point of at least 343°C (650°F), although it is understood that the separation limit of this fraction may vary among refineries and can reach 380°C (716°F). Vacuum column bottoms (also known as pitch or vacuum bottoms) can have a boiling point of at least 524°C (975°F), although it is understood that the separation limit for this fraction may vary among refineries and can reach 538°C ( 1000°F) or even 565°C (1050°F).

In comparison, Alberta light crude oil contains approximately 9 vol.% vacuum residue, while Lloydminster heavy crude contains approximately 41 vol.% vacuum residue, Cold Lake bitumen contains approximately 50 vol.% vacuum residue, and Athabasca bitumen contains approximately 51 vol. % vacuum residue. As a further comparison, relatively light oils such as Dansk Blend from the North Sea region contain only 15% vacuum residue, while lower quality European oils such as Urals contain more than 30% vacuum residue, and oils such as Arab Medium has even higher concentrations, approximately 40% vacuum residue. These examples highlight the importance of the ability to convert vacuum residues when using lower quality crude oils.

Converting heavy oil into useful end products requires expensive processing, such as lowering the boiling point of heavy oil, increasing the hydrogen to carbon ratio, and removing impurities such as metals, sulfur, nitrogen, and coke precursors. Examples of hydrocracking processes using conventional heterogeneous catalysts to upgrade atmospheric column bottoms include fixed bed hydroprocessing, fluidized bed hydroprocessing, and moving bed hydroprocessing. Non-catalytic processes used to upgrade vacuum column bottoms include thermal cracking such as delayed coking, flexicoking, visbreaking and solvent extraction.

The essence of the invention

The present invention describes methods for upgrading a fluidized bed hydroprocessing system for use with less expensive, lower quality substandard feedstocks that otherwise cause severe equipment contamination. Also disclosed are enriched fluidized bed hydroprocessing systems produced using the described methods. The described methods and systems involve the use of a dual catalyst system consisting of a solid supported catalyst and well dispersed particulate (eg, homogeneous) catalyst. The dual catalytic system improves the ability of the enriched fluidized bed hydroprocessing system to adapt to and withstand the negative effects of intermittent use of substandard feedstocks.

In some embodiments, a method for improving a fluidized bed hydroprocessing system for hydroprocessing lower quality heavy oils includes:

(1) the initial operation of a fluidized bed reactor using a heterogeneous catalyst to hydrotreat the heavy petroleum feedstock at an initial rate of formation of converted products;

- 1 043687 (2) subsequent enrichment of a fluidized bed reactor for operation using a dual catalyst system consisting of dispersed particles of a metal sulfide catalyst and a heterogeneous catalyst; and (3) operating an enriched fluidized bed reactor using a dual catalyst system to hydrotreat lower quality heavy oil and/or lower quality feedstock while maintaining the rate of formation of converted products at least the same as the feedstock. speed.

In some embodiments, the lower quality heavy oil and/or lower quality feedstock mixture has at least one lower quality characteristic compared to the original heavy oil feedstock selected from, among other things: (i) a higher boiling point; (ii) higher sulfur concentration; (iii) higher nitrogen concentration; (iv) higher concentration of metals; (v) higher molecular weight; (vi) lower hydrogen to carbon ratio; (vii) higher asphaltene content; and (viii) a higher tendency to form sludge.

In some embodiments, maintaining the conversion rate of hydroprocessing lower quality heavy oil and/or lower quality feedstock using a dual catalyst system involves operating the enriched fluidized bed reactor under the same or more severe conditions as the original reactor operation. with a fluidized bed. Reactor severity includes one or more of operating temperature, throughput, and heavy oil conversion.

In some embodiments, operation of the enriched fluidized bed reactor includes hydroprocessing a lower quality feed mixture containing a heavy oil feedstock (or heavy oil of comparable quality) and at least 5, or at least 10, or at least 20, or at least 30, or at least 40% lower quality heavy oil (or substandard feedstock), and up to 100, 90, 80, 70, 60 or 50%.

In some embodiments, operation of the enriched fluidized bed reactor involves hydroprocessing lower quality heavy oil instead of the original heavy oil feedstock. As an example, a lower quality heavy oil that is blended with or hydroprocessed in place of the original heavy petroleum feedstock contains at least one of heavy crude oil, oil sands bitumen, refinery residue, atmospheric column bottoms having a nominal boiling point at least 343°C (650°F), vacuum column bottoms having a nominal boiling point of at least 524°C (975°F), hot separator bottoms, pitch or vacuum bottoms.

In some embodiments, the dispersed metal sulfide catalyst particles have a size of less than 1 micron, or less than about 500 nm, or less than about 250, or less than about 100, or less than about 50, or less than about 25, or less than about 10, or less than about 5 nm .

In some embodiments, dispersed metal sulfide catalyst particles are formed in situ in the heavy oil from the catalyst precursor. By way of non-limiting example, dispersed metal sulfide catalyst particles can be produced by mixing a catalyst precursor into a bulk heavy oil before thermally decomposing the catalyst precursor to form active metal sulfide catalyst particles. As a further example, methods may include mixing a catalyst precursor with a hydrocarbon diluent to form a dilute precursor mixture, mixing the dilute precursor mixture with a heavy oil to form a conditioned heavy oil, and heating the conditioned heavy oil to decompose the catalyst precursor and form dispersed metal sulfide catalyst particles in situ .

In some embodiments, a method for improving a fluidized bed hydroprocessing system for hydroprocessing lower grade heavy oils includes: (1) initially operating a fluidized bed reactor using a heterogeneous catalyst to hydroprocess a heavy oil feedstock at an initial rate of formation of converted products, wherein the heavy oil feedstock the raw material has at least one quality indicator selected from, among others: (i) boiling point, (ii) sulfur concentration, (iii) nitrogen concentration, (iv) metal concentration, (v) molecular weight, (vi ) hydrogen to carbon ratio, (vii) asphaltene content, or (viii) sludge formation tendency; (2) subsequent enrichment of the fluidized bed reactor to operate using a dual catalyst system consisting of dispersed metal sulfide catalyst particles and a heterogeneous catalyst; and (3) operating an enriched fluidized bed reactor using a dual catalyst system to hydrotreat lower quality heavy oil and/or lower quality feedstock while maintaining the rate of formation of converted products at least the same as the feedstock. speed, wherein the lower quality heavy oil and/or lower quality feedstock mixture has at least one lower quality indicator compared to the original heavy oil feedstock, selected, among other things, from: (i) higher boiling point, (ii) higher sulfur concentration, (iii) higher nitrogen concentration, (iv) higher metal concentration, (v) higher molecular weight, (vi) lower hydrogen to carbon ratio, (vii) higher asphaltene content, or (viii) a higher tendency to form sludge.

In some embodiments, a method for improving a fluidized bed hydroprocessing system for hydroprocessing lower quality heavy oils includes:

(1) the initial operation of a fluidized bed reactor using a heterogeneous catalyst to hydrotreat the heavy petroleum feedstock at an initial rate of formation of converted products;

(2) subsequent enrichment of the fluidized bed reactor to operate using a dual catalyst system consisting of dispersed metal sulfide catalyst particles and a heterogeneous catalyst; and (3) operating an enriched fluidized bed reactor using a dual catalyst system to hydroprocess the lower quality feed mixture while maintaining the rate of formation of converted products at least the same as the original rate, the lower quality feed mixture contains the original heavy oil feedstock or heavy oil of comparable quality and at least 5, or at least 10, or at least 20, or at least 30, or at least 40% heavy oil of lower quality (or substandard quality feedstock) ), and up to 100, 90, 80, 70, 60 or 50%.

In some embodiments, a method of improving a fluidized bed hydroprocessing system for hydroprocessing lower quality heavy oils includes: (1) initially operating a fluidized bed reactor using a heterogeneous catalyst to hydroprocess the heavy oil feedstock at the original conversion rate; (2) subsequent enrichment of the fluidized bed reactor to operate using a dual catalyst system consisting of dispersed metal sulfide catalyst particles and a heterogeneous catalyst; and (3) operating an enriched fluidized bed reactor using a dual catalyst system to hydrotreat lower quality heavy oil in place of the original heavy oil feedstock while maintaining the rate of formation of converted products at least the same as the original rate.

These and other advantages and features of the present invention will become more apparent from the following description and appended claims, or may be learned by practice of the invention as set forth below.

Brief description of drawings

To further explain the above and other advantages and features of the present invention, a more detailed description of the invention will be given with reference to specific embodiments thereof, which are illustrated in the accompanying drawings. It should be noted that these drawings reflect only typical embodiments of the invention and therefore should not be construed as limiting its scope.

The invention will be described and explained more specifically and in detail by reference to the accompanying drawings, in which:

in fig. Figure 1 shows the hypothetical molecular structure of asphaltene;

in fig. 2A and B schematically illustrate exemplary fluidized bed reactors;

in fig. 2C schematically illustrates an exemplary fluidized bed hydroprocessing system comprising multiple fluidized bed reactors;

in fig. 2D schematically illustrates an exemplary fluidized bed hydroprocessing system comprising multiple fluidized bed reactors and an intermediate separator between the two reactors;

in fig. 3 is a flow diagram illustrating an example of a process for enriching a fluidized bed reactor for working with raw materials of non-standard quality;

in fig. 4 schematically illustrates an exemplary fluidized bed hydroprocessing system using a dual catalyst system;

in fig. 5 schematically illustrates a pilot scale fluidized bed hydroprocessing system configured to use either a heterogeneous catalyst alone or a dual catalyst system including a heterogeneous catalyst and dispersed metal sulfide particles;

in fig. 6 is a line graph showing the conversion of C ₇ asphaltenes at various time intervals during the refining of heavy oil containing 20% substandard feedstock using a fluidized bed of a single solid supported catalyst or a dual catalyst system;

in fig. 7 is a line graph showing the sediment content at various intervals

- 3 043687 time when processing heavy oil containing various raw materials of non-standard quality, when using a fluidized bed of a single solid catalyst on a carrier or a double catalytic system; and in fig. 8 is a line graph showing the thermal load of a vacuum column bottoms heat exchanger when processing heavy oil containing substandard feedstocks using a fluidized bed of a single solid supported catalyst or a dual catalyst system.

Detailed Description of Preferred Embodiments

I. Introduction and definitions.

The present invention relates to methods for upgrading a fluidized bed hydroprocessing system for hydroprocessing lower grade heavy oils and to enriched fluidized bed hydroprocessing systems produced by the methods described. The methods and systems include (1) using a dual catalyst system and (2) operating a fluidized bed reactor to hydrotreat lower grade heavy oil while maintaining or increasing the rate of conversion of converted products.

As an example, a method for upgrading a fluidized bed hydroprocessing system for hydroprocessing a lower quality heavy oil comprises: (1) initially operating a fluidized bed reactor using a heterogeneous catalyst to hydroprocess a heavy oil feedstock at an initial conversion rate; (2) subsequent enrichment of the fluidized bed reactor to operate using a dual catalyst system consisting of dispersed metal sulfide catalyst particles and a heterogeneous catalyst; and (3) operating an enriched fluidized bed reactor using a dual catalyst system to hydrotreat lower quality heavy oil and/or lower quality feedstock while maintaining the rate of formation of converted products at least the same as the feedstock. speed.

The term heavy petroleum feedstock refers to heavy crude oil, oil sands bitumen, sludge and refinery residues (e.g., visbreaker bottoms), and any other lower grade materials that contain significant amounts of high-boiling hydrocarbon fractions, and/or that include significant amounts of asphaltenes, which can deactivate the heterogeneous catalyst and/or cause or lead to the formation of coke and sludge precursors. Examples of heavy petroleum feedstocks include, but are not limited to, Lloydminster heavy oil, Cold Lake bitumen, Athabasca bitumen, atmospheric column bottoms, vacuum column bottoms, residue (or bottoms), pitch, vacuum bottoms (e.g., Urals VR, Arab Medium VR, Athabasca VR, Cold Lake VR, Maya VR and Chichimene VR), deasphalted fluids produced by solvent deasphalting, asphaltene fluids produced as a by-product of deasphalting, and the non-volatile liquid fractions that remain after the dispatch of crude oil, tar sands bitumen, liquefied coal, oil shale or coal tar raw materials for distillation, hot separation, solvent extraction and the like. As a further example, atmospheric column bottoms (ATB) may have a nominal boiling point of at least 343°C (650°F), although it is understood that the cutoff may vary between refineries and may be as high as 380°C (716°F). °F). Vacuum column bottoms may have a boiling point of at least 524°C (975°F), although it is understood that the cutoff point may vary from refinery to refinery and may reach 538°C (1000°F) or even 565°C ( 1050°F).

The term asphaltene refers to substances in heavy petroleum crudes that are generally insoluble in paraffinic solvents such as propane, butane, pentane, hexane and heptane. Asphaltenes may include layers of condensed ring compounds held together by heteroatoms such as sulfur, nitrogen, oxygen and metals. Asphaltenes include a wide range of complex compounds containing from 80 to 1200 carbon atoms, with predominant molecular weights determined by dissolution methods ranging from 1200 to 16900. Approximately 80-90% of the metals in crude oil are contained in the asphaltene fraction, which, along with the high concentration nonmetallic heteroatoms makes asphaltene molecules more hydrophilic and less hydrophobic than other hydrocarbons in crude oil. A hypothetical structure of an asphaltene molecule developed by A.G. Bridge and co-workers at Chevron is shown in FIG. 1. In general, asphaltenes are usually defined based on the results of insoluble substance methods, and more than one definition of asphaltenes may be used. In particular, the commonly used definition of asphaltenes is heptane-insoluble compounds minus toluene-insoluble compounds (i.e., asphaltenes are soluble in toluene; precipitates and residues that are insoluble in toluene are not considered asphaltenes). Asphaltenes defined in this way may be called C ₇ asphaltenes. However, an alternative definition, measured as pentane-insoluble compounds minus toluene-insoluble compounds, and commonly referred to as C ₅ asphaltenes, can also be used with equal confidence. In the examples of the present invention, the determination of C ₇ asphaltenes is used, but it can be easily

- 4 043687 replaced by the definition of C ₅ asphaltenes.

The quality of heavy oil is measured by at least one indicator selected from, inter alia: (i) boiling point; (ii) sulfur concentrations; (iii) nitrogen concentrations; (iv) metal concentrations; (v) molecular weight; (vi) hydrogen to carbon ratios; (vii) asphaltene content; and (viii) tendency to form sediment.

The lower quality heavy oil and/or lower quality feedstock mixture has at least one lower quality indicator compared to the original heavy oil feedstock selected from, among other things: (i) a higher boiling point; (ii) higher sulfur concentration; (iii) higher nitrogen concentration; (iv) higher concentration of metals; (v) higher molecular weight (often defined by higher density and viscosity); (vi) lower hydrogen to carbon ratio; (vii) higher asphaltene content; and (viii) a higher tendency to form sludge.

The term substandard feedstocks refers to lower quality heavy oils and feedstock mixtures of lower quality heavy oils having at least one lower quality indicator compared to the original heavy oil feedstock.

The terms hydrocracking and hydroconversion refer to a process whose primary purpose is to reduce the boiling range of heavy petroleum feedstocks and in which a significant portion of the feedstock is converted into products with boiling ranges lower than those of the feedstock. Hydrocracking or hydroconversion typically involves breaking down larger hydrocarbon molecules into smaller molecular fragments having fewer carbon atoms and a higher ratio of hydrogen to carbon. The mechanism by which hydrocracking occurs typically involves the formation of hydrocarbon free radicals through a process of thermal cleavage, followed by capping of the ends or residues of the free radicals with hydrogen. Hydrogen atoms or radicals that react with hydrocarbon free radicals during the hydrocracking process can be formed on or through active catalytic sites.

The term hydrotreating refers to operations whose primary purpose is to remove impurities such as sulfur, nitrogen, oxygen, halides and trace metals from feedstocks and saturate olefins and/or stabilize hydrocarbon free radicals by reacting them with hydrogen rather than through reactions with each other. The main goal is not to change the boiling range of the feedstock. Hydrotreating is most often carried out using a fixed bed reactor, although other hydroprocessing reactors, such as a fluidized bed hydrotreater, can also be used for hydrotreating.

Of course, hydrocracking or hydroconversion may also involve the removal of sulfur and nitrogen from feedstocks, as well as olefin saturation and other reactions typically associated with hydrotreating. The terms hydroprocessing and hydroconversion refer broadly to the processes of hydrocracking and hydrotreating, which define opposite ends of the spectrum and everything within the spectrum.

The term hydrocracking reactor refers to any vessel in which hydrocracking (i.e., reducing the boiling range) of a feedstock in the presence of hydrogen and a hydrocracking catalyst is the primary purpose. Hydrocracking reactors are characterized by having an inlet into which heavy petroleum feedstock and hydrogen can be introduced, an outlet from which enriched feedstock or material can be removed, and sufficient thermal energy to generate hydrocarbon free radicals to cause the breakdown of larger hydrocarbons. molecules into smaller molecules. Examples of hydrocracking reactors include, but are not limited to, slurry phase reactors (i.e., two-phase gas-liquid system), fluidized bed reactors (i.e., three-phase gas-liquid-solid system), fixed-bed reactors (i.e., three-phase system which involves a liquid feed dripping downwards or upwards through a fixed bed of solid heterogeneous catalyst, with hydrogen usually supplied in co-current flow, but possibly in counter-current flow with the heavy oil).

The term hydrocracking temperature refers to the minimum temperature required to achieve significant hydrocracking of heavy petroleum feedstocks. Typically, hydrocracking temperatures are preferably in the range of from about 399°C (750°F) to about 460°C (860°F), more preferably in the range of from about 418°C (785°F) to about 443°C ( 830°F) and most preferably in the range from about 421°C (790°F) to about 440°C (825°F).

The term gas-liquid slurry hydrocracking reactor refers to a hydroprocessing reactor that includes a continuous liquid phase and a gaseous dispersed phase that forms a suspension of gas bubbles in the liquid phase. The liquid phase typically contains hydrocarbon feedstock, which may have a low concentration of dispersed metal sulfide catalyst particles, and the gaseous phase typically contains hydrogen gas, hydrogen sulfide, and vaporized low boiling hydrocarbon products. The liquid phase may optionally include a hydrogen donor solvent. The term three-phase gas-liquid-solid slurry hydrocracking reactor is used when a solid catalyst is used together with a liquid and a gas. The gas may contain hydrogen, hydrogen sulfide and vaporized low-boiling hydrocarbons

- 5 043687 products. The term slurry phase reactor broadly refers to both types of reactors (eg, reactors with dispersed metal sulfide catalyst particles, reactors with dispersed catalyst with micron-sized or larger particles, and reactors that include both).

The terms solid heterogeneous catalyst, heterogeneous catalyst, and supported catalyst refer to catalysts that are commonly used in fluidized bed and fixed bed hydroprocessing systems, including catalysts primarily intended for hydrocracking, hydroconversion, hydrodemetallization, and/or hydrotreating. A heterogeneous catalyst typically contains: (i) a catalyst support having a large surface area and interconnected channels or pores; and (ii) small active catalyst particles such as cobalt, nickel, tungsten and molybdenum sulfides dispersed within the channels or pores. The support pores are typically limited in size to maintain the mechanical integrity of the heterogeneous catalyst and prevent degradation and excessive dust formation in the reactor. Heterogeneous catalysts can be obtained in the form of cylindrical granules or spherical solid material.

The terms dispersed metal sulfide catalyst particles and dispersed catalyst refer to catalyst particles having a size of less than 1 micron, such as less than about 500, or less than about 250, or less than about 100, or less than about 50 e, or less than about 25, or less about 10, or less than about 5 nm in diameter. The term dispersed metal sulfide catalyst particles may include molecular or molecularly dispersed catalyst compounds.

The term molecularly dispersed catalyst refers to catalyst compounds that are substantially dissolved or dissociated from other catalyst compounds or molecules in the hydrocarbon feedstock or suitable diluent. It may include very small catalyst particles that contain several catalyst molecules linked together (eg, 15 molecules or less).

The term residual catalyst particles refers to catalyst particles that remain in the enrichment material when transferred from one vessel to another (eg, from a hydroprocessing reactor to a separator and/or another hydroprocessing reactor).

The term conditioned feed refers to a hydrocarbon feed with which the catalyst precursor has been combined and mixed to a sufficient extent such that upon decomposition of the catalyst precursor and formation of the active catalyst, the catalyst will contain dispersed metal sulfide catalyst particles formed in situ in the feed.

The terms fortify, fortify, and fortified, when used to describe a feedstock that is or has been hydroprocessed, or the resulting material or product, refer to one or more of the following: reduction in the molecular weight of the feedstock, reduction in the boiling range of the feedstock, reduction in the concentration of asphaltenes, reduction in the concentration of free hydrocarbons radicals and/or reduction of impurities such as sulfur, nitrogen, oxygen, halides and metals.

The term severity usually refers to the amount of energy that is introduced into heavy oil during hydroprocessing, and is often related to the operating temperature of the hydroprocessing reactor (i.e., higher temperature associated with greater severity; lower temperature associated with less severity) combined with duration specified temperature effects. Increased severity typically increases the amount of conversion products produced by the hydroprocessing reactor, including both desired conversion products and undesired conversion products. Desirable conversion products include hydrocarbons with reduced molecular weight, boiling point and specific gravity, and may include end products such as naphtha, diesel fuel, jet fuel, kerosene, wax, fuel oil and the like. Other desirable conversion products include higher boiling point hydrocarbons, which can be further processed using conventional refining and/or distillation processes. Undesirable conversion products include coke, sludge, metals and other solids that can deposit on hydroprocessing equipment and cause fouling of, for example, reactor internals, separators, filters, pipes, towers and heterogeneous catalyst. Undesired conversion products can also refer to unconverted bottoms that remain after distillation, such as atmospheric column bottoms (ATB) or vacuum column bottoms (VTB). Minimizing unwanted conversion products reduces equipment contamination and shutdowns required to clean equipment. However, a desirable amount of unconverted bottoms may be present to enable downstream separation equipment to function properly and/or to provide a liquid medium for transporting contained coke, sludge, metals and other solids that might otherwise settle out and contaminate equipment, but which can be removed with remaining bottoms.

In addition to temperature, hardness may be related to conversion and/or throughput

- 6 043687 ability. Whether increased severity will mean increased conversion and/or increased or decreased throughput may depend on the quality of the heavy oil feedstock and/or the material balance of the overall hydroprocessing system. For example, in cases where it is desired to convert more feed material and/or feed more material to downstream equipment, increased rigidity may primarily involve increased throughput, without necessarily increasing the conversion rate. This may include the case where bottoms fractions (ATB and/or VTB) are sold as fuel oil and increasing conversion without increasing throughput may reduce the amount of this product. Where it is desirable to increase the ratio of enriched materials to bottoms fractions, it may be desirable to first increase conversion without necessarily increasing throughput. When the quality of the heavy oil introduced into the hydroprocessing reactor fluctuates, it may be desirable to selectively increase or decrease conversion and/or throughput to maintain the desired ratio of enriched materials to bottoms fractions and/or the desired absolute amount or amounts of final product(s) produced.

The terms conversion and conversion rate refer to the proportion, often expressed as a percentage, of heavy oil that is successfully converted to lower boiling point and/or lower molecular weight species. Conversion is expressed as the percentage of original bottoms (i.e., components with a boiling point above a certain bottoms cutoff point) that are converted into products with a boiling point below a certain cutoff point. The definition of residue separation limit may vary and may nominally include 524°C (975°F), 538°C (1000°F), 565°C (1050°F) and the like. It can be determined by analyzing the distillation of raw materials and product streams to determine the concentration of components with a boiling point above a certain separation limit. The conversion rate is expressed as (F-P)/F, where F is the amount of bottoms in the combined feed streams and P is the amount in the combined product streams, with both feed and product bottoms being based on the same determining the boundaries of the department. The amount of bottoms is most often determined on the basis of the mass of components with a boiling point above a certain separation limit, but volumetric or molar determinations may also be used.

The term throughput refers to the amount of feed material that is introduced into the hydroprocessing reactor as a function of time. It is also related to the total amount of conversion products recovered from the hydroprocessing reactor, including the total amount of desired and undesired products. Throughput can be expressed in volumetric units, such as barrels per day, or in mass units, such as metric tons per hour. Typically, throughput is defined as the mass or volumetric flow rate of only a single heavy petroleum feedstock (for example, vacuum column bottoms or the like). This definition generally does not include quantities of diluents or other components that may sometimes be included in the total feed to a hydroconversion unit, although a definition that includes these other components may also be used.

The term sediment refers to solids contained in a liquid stream that can settle. Precipitates may include inorganic matter, coke, or insoluble asphaltenes that precipitate upon cooling after conversion. Sediment in petroleum products is typically measured using the hot filterability test procedure IP-375 for total sediment in residual fuel oil, published as part of ISO 10307 and ASTM D4870. Other tests include the IP-390 sedimentation test and the Shell hot filterability test. Sludge is associated with oil components that tend to form solids during processing and transportation. These solids-forming components have many undesirable effects during the hydroconversion process, including deterioration of product quality and operational problems associated with contamination. It should be noted that although the strict definition of sludge is based on the measurement of solids in a sedimentation test, the term is generally used more loosely to refer to the solids-forming components of the oil itself.

The term fouling refers to the formation of an undesirable phase (contaminant) that interferes with processing.

The contaminant is typically a carbonaceous material or solid that settles and accumulates inside process equipment. Contamination can result in production losses due to equipment shutdowns, reduced equipment performance, increased energy consumption due to the insulating effect of contaminant deposits in heat exchangers or heaters, increased operating costs for equipment cleaning, reduced efficiency of fractionation columns, and reduced heterogeneous catalyst reactivity.

II. Fluidized bed hydroprocessing systems and reactors.

In fig. 2A-D schematically illustrate non-limiting examples of fluidized bed hydroprocessing systems and reactors used for the hydroprocessing of hydrocarbon feedstocks, such as heavy oil, that can be upgraded using a dual catalyst system in accordance with the present invention. It should be noted that exemplary fluidized bed hydroprocessing systems and reactors may include intermediate separation, integrated hydrotreating, and/or integrated hydrocracking.

In fig. 2A is a schematic illustration of a fluidized bed hydroprocessing reactor 10 used in the LC-Fining hydrocracking system developed by C-E Lummus. The fluidized bed reactor 10 includes an inlet 12 at the bottom through which raw material 14 and compressed hydrogen gas 16 are introduced, and an outlet 18 at the top through which the hydroprocessed material 20 is discharged.

Reactor 10 also includes a decompressed catalyst zone 22 containing a heterogeneous catalyst 24 that is maintained in a decompacted or fluidized state against gravity by the upward movement of liquid hydrocarbons and gas (shown schematically as bubbles 25) through the fluidized bed reactor 10. The lower end of the decompressed catalyst zone 22 is limited by a distribution mesh plate 26, which separates the decompressed catalyst zone 22 from the lower free zone 28 of a heterogeneous catalyst located between the bottom of the fluidized bed reactor 10 and the distribution mesh plate 26. The distribution mesh plate 26 is configured to distribute gaseous hydrogen and hydrocarbons evenly throughout the reactor and prevents the heterogeneous catalyst 24 from falling under the influence of gravity into the lower free zone 28 of the heterogeneous catalyst. The upper end of the decompressed catalyst zone 22 is the height at which the downward force of gravity begins to equal or exceed the lifting force of the upward movement of feed and gas through the fluidized bed reactor 10 when the heterogeneous catalyst 24 reaches a predetermined level of decompression or separation. Above the decompressed catalyst zone 22 is the upper free zone 30 of the heterogeneous catalyst.

Hydrocarbons and other materials in the fluidized bed reactor 10 are continuously recirculated from the upper free zone 30 of the heterogeneous catalyst to the lower free zone 28 of the heterogeneous catalyst through a recycle channel 32 located in the center of the fluidized bed reactor 10 and connected to an ebullation pump 34 at the bottom of the reactor 10 with fluidized bed. In the upper part of the recirculation channel 32 there is a funnel-shaped recirculation bowl 36, through which the raw material is removed from the upper free zone 30 of the heterogeneous catalyst. The material entrained downward through the recirculation channel 32 enters the lower free zone 28 of the catalyst and thereafter passes upward through the distribution screen plate 26 and into the decompressed catalyst zone 22, where it mixes with the freshly added feed 14 and hydrogen gas 16 entering the reactor 10 s fluidized bed 10 through inlet 12. Continuous upward circulation of the mixed materials through the fluidized bed reactor 10 effectively maintains the heterogeneous catalyst 24 in a decompacted or fluidized state in the decompressed catalyst zone 22, minimizes channeling effects, regulates reaction rates, and maintains the heat generated in exothermic reactions. hydrogenation, at a safe level.

Fresh heterogeneous catalyst 24 is introduced into the fluidized bed reactor 10, such as the depressurized catalyst zone 22, through a catalyst inlet tube 38 that extends through the top of the fluidized bed reactor 10 directly into the depressurized catalyst zone 22. The spent heterogeneous catalyst 24 is discharged from the decompressed catalyst zone 22 through a catalyst outlet tube 40, which extends from the lower end of the decompressed catalyst zone 22 through the distribution screen plate 26 and into the bottom of the fluidized bed reactor 10. It should be appreciated that catalyst outlet tube 40 is unable to differentiate between fully spent catalyst, partially spent but active catalyst, and freshly added catalyst, so a random distribution of heterogeneous catalyst 24 is typically discharged from the fluidized bed reactor 10 as spent catalyst.

The enriched material 20 withdrawn from the fluidized bed reactor 10 may be introduced into a separator 42 (eg, a hot separator, an intermediate pressure differential separator, or a distillation column). A separator 42 separates one or more volatile fractions 46 from a non-volatile fraction 48.

In fig. 2B is a schematic illustration of a fluidized bed reactor 110 used in an H-Oil hydrocracking system developed by Hydrocarbon Research Incorporated and currently licensed to Axens. The fluidized bed reactor 110 includes an inlet 112 through which heavy petroleum feedstock 114 and compressed hydrogen gas 116 are introduced, and an outlet 118 at the top through which the enriched material 120 is discharged. The decompressed catalyst zone 122 containing the heterogeneous catalyst 124 is limited by a distribution area. a mesh plate 126 that separates the decompressed catalyst zone 122 from the lower free catalyst zone 128 between the bottom of the reactor 110 and the distribution mesh plate 126, and an upper end 129 that defines the approximate boundary between the decompacted catalyst zone 122 and the upper free catalyst zone 130. The dashed boundary line 131 schematically illustrates an approximate

- 8 043687 level of the heterogeneous catalyst 124 when it is not in a decompressed or fluidized state.

Materials are continuously recirculated in the reactor 110 through a recirculation channel 132 connected to an ebullation pump 134 located outside the reactor 110. The materials are entrained through a funnel-shaped recirculation bowl 136 from the upper free zone 130 of the catalyst. The recycle bowl 136 has a spiral shape that helps separate hydrogen bubbles 125 from the recycle material 132 to prevent cavitation of the ebullation pump 134. The recycle material 132 enters the lower catalyst free zone 128 where it mixes with fresh feed 116 and hydrogen gas 118, and the mixture passes through the distribution screen plate 126 into the decompressed catalyst zone 122. Fresh catalyst 124 is introduced into the decompressed catalyst zone 122 through catalyst inlet tube 136, and spent catalyst 124 is removed from the decompressed catalyst zone 122 through catalyst outlet tube 140.

The main difference between the H-Oil fluidized bed reactor 110 and the LC-Fining fluidized bed reactor 10 is the location of the ebullation pump. The ebullation pump 134 in the H-Oil reactor 110 is located outside the reaction chamber. The recycle feed is introduced through a recycle recycle port 141 in the bottom of the reactor 110. The recycle port 141 includes a distributor 143 that promotes uniform distribution of materials in the lower free zone 128 of the catalyst. The enriched material 120 is shown to be sent to a separator 142, which separates one or more volatile fractions 146 from a non-volatile fraction 148.

In fig. 2C schematically illustrates a fluidized bed hydroprocessing system 200 comprising multiple fluidized bed reactors. The hydroprocessing system 200, as exemplified by the LC-Fining hydroprocessing unit, may include three fluidized bed reactors 210 operating in series to enrich the feedstock 214. The feedstock 214 is introduced into the first fluidized bed reactor 210a along with hydrogen gas 216, both of which pass through through appropriate heaters before entering the reactor. The enriched material 220a from the first fluidized bed reactor 210a is introduced along with additional hydrogen gas 216 into the second fluidized bed reactor 210b. The enriched material 220b from the second fluidized bed reactor 210b is introduced along with additional hydrogen gas 216 into the third fluidized bed reactor 210c.

It should be understood that one or more intermediate separators may optionally be located between the first and second reactors 210a, 210b and/or the second and third reactors 210b, 210c, to remove lower boiling fractions and gases from the non-volatile fraction containing liquid hydrocarbons and remaining dispersed hydrocarbons. metal sulfide catalyst particles. It may be desirable to remove lower alkanes such as hexanes and heptanes, which are valuable fuel products but poor solvents for asphaltenes. Removing volatile materials between multiple reactors increases the formation of valuable products and increases the solubility of asphaltenes in the liquid hydrocarbon fraction fed to the downstream reactor(s). Both improve the efficiency of the entire hydroprocessing system.

The enriched material 220c from the third fluidized bed reactor 210c is sent to a high temperature separator 242a, which separates the volatile and nonvolatile fractions. The volatile fraction 246a passes through a heat exchanger 250, which preheats the hydrogen gas 216 before being introduced into the first fluidized bed reactor 210a. The slightly cooled volatile fraction 246a is sent to a mid-temperature separator 242b, which separates the remaining volatile fraction 246b from the resulting liquid fraction 248b, which is formed as a result of cooling by heat exchanger 250. The remaining volatile fraction 246b is sent downstream to a low-temperature separator 242c for further separation into gaseous fraction 252c and a degassed liquid fraction 248c.

The liquid fraction 248a from the high temperature separator 242a is sent along with the resulting liquid fraction 248b from the medium temperature separator 242b to the low pressure separator 242d, which separates the hydrogen-rich gas 252d from the degassed liquid fraction 248d, which is then mixed with the degassed liquid fraction 248c from the low temperature separator 242c and separated into product fractions. The gaseous fraction 252c from the low temperature separator 242c is purified into a tail gas, purge gas, and hydrogen gas 216. The hydrogen gas 216 is compressed, mixed with make-up hydrogen gas 216a, and either passed through a heat exchanger 250 and introduced into the first fluidized bed reactor 210a along with feedstock 2 16 , or introduced directly into the second and third fluidized bed reactors 210b and 210c.

In fig. 2D schematically illustrates a fluidized bed hydroprocessing system 200 containing multiple fluidized bed reactors, similar to the system depicted in FIG. 2C, but showing an intermediate separator 221 located between the second and third reactors 210b, 210c (although the intermediate separator 221 may be located between the first and second reactors 210a, 210b). As illustrated, the effluent from the second stage reactor 210b enters an intermediate separator 221, which may be a high temperature, high pressure separator. The liquid fraction from separator 221 is combined with a portion of the recycle hydrogen from line 216 and then enters third stage reactor 210c. The vapor fraction from the intermediate separator 221 bypasses the third stage reactor 210c, mixes with the effluent from the third stage reactor 210c, and then enters the high temperature high pressure separator 242a.

This allows the lighter, richer components formed in the first two stage reactors to bypass the third stage reactor 210c. The advantages of this are: (1) a reduced steam load on the third stage reactor, which increases the utilization of the third stage reactor for conversion of remaining heavy components, and (2) a reduced concentration of antisolvent components (saturated hydrocarbons) that can destabilize asphaltenes in the third stage reactor 210c .

In preferred embodiments, hydroprocessing systems are configured and operated to promote hydrocracking reactions rather than simply hydrotreating, which is a less severe form of hydroprocessing. Hydrocracking involves the breaking of carbon-carbon molecular bonds, such as reducing the molecular weight of larger hydrocarbon molecules and/or ring opening of aromatic compounds. Hydrotreating, on the other hand, involves primarily the hydrogenation of unsaturated hydrocarbons, with minimal or no disruption of the molecular carbon-carbon bonds. To promote hydrocracking rather than just hydrotreating reactions, the hydroprocessing reactor(s) are preferably operated at a temperature in the range of about 750°F (399°C) to about 860°F (460°C), more preferably in the range of about 780° F (416°C) to about 830°F (443°C), preferably operating at pressures in the range of about 1000 psig. inch g. (6.9 MPa) to approximately 3000 psi. inch g. (20.7 MPa), more preferably in the range of about 1500 psi. inch g. (10.3 MPa) to approximately 2500 psi. inch g. (17.2 MPa), and preferably operate at a space velocity (e.g., liquid hourly space velocity, or LHSV, defined as the ratio of feed volume to reactor volume per hour) in the range of about 0.05 to about 0.45, more preferably ranging from about 0.15 to about 0.35 h' ¹ . The difference between hydrocracking and hydrotreating can also be expressed in terms of bottoms conversion rates (with hydrocracking resulting in a significant degree of conversion of higher boiling hydrocarbons to lower boiling hydrocarbons, whereas hydrotreating does not). The hydroprocessing systems described in the present invention can result in bottoms conversion in the range of about 40 to about 90, preferably in the range of about 55 to about 80%. The preferred conversion rate range usually depends on the type of feedstock due to differences in processing complexity between different types of feedstocks. Typically, the conversion will be at least about 5, preferably at least about 10% higher than if the fluidized bed reactor was operated prior to upgrading using the dual catalyst system described herein.

III. Enrichment of a fluidized bed hydroprocessing reactor. FIG. 3 is a flow diagram that illustrates an example of a fluidized bed reactor enrichment process using a dual catalytic system for hydroprocessing substandard feedstocks and handling substandard feedstocks. In particular, in FIG. 3 illustrates a process comprising: (1) initially operating a fluidized bed reactor using a heterogeneous catalyst to hydrotreat a heavy petroleum feedstock at an initial rate of formation of converted products; (2) adding dispersed metal sulfide catalyst particles to the fluidized bed reactor to form an enriched fluidized bed reactor having a dual catalyst system consisting of dispersed metal sulfide catalyst particles and a heterogeneous catalyst; and (3) operating an enriched fluidized bed reactor using a dual catalyst system to batch hydrotreat feedstocks containing one or more substandard feedstocks (e.g., lower quality heavy oil and/or lower quality feedstock blend) while maintaining speed formation of converted products at at least the same level as the original rate.

In some embodiments, the heterogeneous catalyst used in the initial operation of the fluidized bed reactor at the initial conversion rate is a commercially available catalyst that is typically used in fluidized bed reactors. To achieve maximum efficiency, the initial rate of formation of converted products can advantageously be obtained at a reactor stringency that keeps sludge formation and fouling within acceptable limits. Hydroprocessing of lower quality substandard feedstocks without fluidized bed reactor upgrading using a dual catalytic system may consequently result in excessive sludge formation and unwanted equipment fouling, which would otherwise require more frequent shutdown and cleaning of the hydroprocessing reactor and associated equipment such as pipes , towers, filters, heaters, heterogeneous catalyst and/or separation equipment.

To combat the tendency of substandard feedstocks to increase sludge formation, equipment fouling, and the need for more frequent shutdowns and maintenance, the fluidized bed reactor is upgraded to begin using a dual catalyst system containing a heterogeneous catalyst and dispersed metal sulfide catalyst particles.

In some embodiments, operation of the enriched fluidized bed reactor includes hydroprocessing a lower quality feed mixture containing a heavy oil feedstock (or heavy oil of comparable quality) and at least 5, or at least 10, or at least 20, or at least 30, or at least 40% lower quality heavy oil (or substandard feedstock), and up to 100, 90, 80, 70, 60 or 50%.

In some embodiments, operation of the enriched fluidized bed reactor involves hydroprocessing lower quality heavy oil instead of the original heavy oil feedstock. By way of example, a lower quality heavy oil that is blended with or hydroprocessed in place of the original heavy petroleum feedstock contains at least one of heavy crude oil, oil sands bitumen, refinery residue, atmospheric column bottoms having a nominal boiling point at least 343°C (650°F), vacuum column bottoms having a nominal boiling point of at least 524°C (975°F), hot separator bottoms, pitch or vacuum bottoms.

Operating the enriched fluidized bed reactor to maintain or increase the initial conversion rate may involve operating at the same or increased severity, even if the hydroprocessed feedstock is of substandard quality, compared to the original operation of the fluidized bed reactor. Increased stringency may include operating at a higher temperature, increased conversion and/or increased throughput than the original operation at the original conditions.

In some embodiments, operating the enrichment reactor under harsh conditions includes increasing the operating temperature of the enriched fluidized bed reactor by nominally at least about 2.5, or at least about 5, at least about 7.5, or at least about by 10, or at least about 15°C, than when operating under initial conditions.

In some embodiments, operating an enriched conversion reactor comprises increasing the conversion of the enriched fluidized bed reactor by at least about 1%, or at least about 5%, or at least about 10%, or at least about 15%, than when working under initial conditions.

In some embodiments, operating an enriched reactor with increased throughput includes increasing the throughput of the enriched fluidized bed reactor by at least about 2.5, or at least about 5, or at least about 10, or at least about 15, or at least about 20% (eg, 24%) than when operating under baseline conditions.

Dispersed metal sulfide catalyst particles can be prepared separately and then added to a fluidized bed reactor to form a dual catalyst system. Alternatively or additionally, at least a portion of the dispersed metal sulfide catalyst particles may be formed in situ in a fluidized bed reactor.

In some embodiments, dispersed metal sulfide catalyst particles are effectively formed in situ throughout the heavy petroleum feedstock. This can be achieved by initially mixing the catalyst precursor throughout the heavy petroleum feedstock to form a conditioned feedstock and appropriately heating the conditioned feedstock to decompose the catalyst precursor and initiate or allow the catalyst metal to react with the sulfur in the heavy oil, and/or when added to the heavy oil. oil with the formation of dispersed particles of metal sulfide catalyst.

The catalyst precursor may be oil soluble and may have a decomposition temperature in the range from about 100°C (212°F) to about 350°C (662°F), or in the range from about 150°C (302°F) to about 300°C (572°F), or in the range of about 175°C (347°F) to about 250°C (482°F). Examples of catalyst precursors include organometallic complexes or compounds, particularly oil-soluble compounds or transition metal organic acid complexes, having a sufficiently high decomposition temperature or range of temperatures to avoid significant decomposition when mixed with heavy petroleum feedstocks under suitable mixing conditions. When mixing a catalyst precursor with a hydrocarbon petroleum diluent, it is preferable to maintain the diluent at a temperature below which significant decomposition of the catalyst precursor occurs. One skilled in the art, following the present disclosure, can select a mixing temperature profile that results in deep mixing of the selected precursor composition without significant degradation to form dispersed metal sulfide catalyst particles.

An example of a catalyst precursor includes, but is not limited to, molybdenum-2-ethylhexanoate, molybdenum octoate, molybdenum naphthenate, vanadium naphthenate, vanadium octoate, molybdenum hexacarbonyl, vanadium hexacarbonyl, and iron pentacarbonyl. Other catalyst precursors include molybdenum salts containing many cationic molybdenum atoms and many carboxylate anions from

- 11 043687 at least 8 carbon atoms and which are at least one of (a) aromatic, (b) alicyclic or (c) branched, unsaturated and aliphatic. As an example, each carboxylate anion may have from 8 to 17 carbon atoms or from 11 to 15 carbon atoms. Examples of carboxylate anions that correspond to at least one of the above categories include carboxylate anions derived from carboxylic acids selected from the group consisting of 3-cyclopentylpropionic acid, cyclohexanebutyric acid, biphenyl-2carboxylic acid, 4-heptylbenzoic acid, 5-phenylvaleric acid acid, geranic acid (3,7-dimethyl-2,6-octadienoic acid), and combinations thereof.

In other embodiments, carboxylate anions for use in the preparation of oil-soluble, thermally stable molybdenum catalyst precursor compounds are derived from carboxylic acids selected from the group consisting of 3-cyclopentylpropionic acid, cyclohexanebutyric acid, biphenyl-2-carboxylic acid, 4-heptylbenzoic acid, 5phenylvaleric acid, geranoic acid (3,7-dimethyl-2,6-octadienoic acid), 10undecenoic acid, dodecanoic acid, and combinations thereof. Molybdenum catalyst precursors prepared using carboxylate anions derived from the above carboxylic acids have been found to have improved thermal stability.

The heat-resistant catalyst precursors may have a first decomposition temperature greater than 210, greater than about 225, greater than about 230, greater than about 240, greater than about 275, or greater than about 290°C. Such catalyst precursors may have a maximum decomposition temperature greater than 250, or greater than about 260, or greater than about 270, or greater than about 280, or greater than about 290, or greater than about 330°C.

One skilled in the art, following the present disclosure, can select a mixing temperature profile that results in deep mixing of the selected precursor composition without significant degradation to form dispersed metal sulfide catalyst particles.

Since it is within the scope of the invention to directly mix the catalyst precursor composition with the heavy petroleum feedstock, in such cases care must be taken to mix the components for a time sufficient to thoroughly mix the precursor composition with the feedstock before significant degradation of the precursor composition occurs. For example, US Pat. No. 557,8197 to Cyr et al., the disclosure of which is incorporated by reference, describes a process in which molybdenum 2-ethylhexanoate is mixed with vacuum column bitumen residue for 24 hours before heating the resulting mixture in a reaction vessel to form the compound catalyst and hydrocracking (see column 10, lines 4-43). Although 24 hours of mixing under experimental conditions may be entirely acceptable, such long mixing times make some industrial operations prohibitively expensive. To ensure thorough mixing of the catalyst precursor in the heavy oil before heating to form the active catalyst, several mixing steps are carried out with various mixing equipment prior to heating the conditioned feedstock. It may include one or more in-line low shear mixers, followed by one or more high shear mixers, followed by a surge tank and pump circulation system, and then one or more high pressure multistage pumps used to compress the feedstock. stream before introducing it into the hydroprocessing reactor.

In some embodiments, the conditioned feedstock is preheated by a heating device prior to introduction into the hydroprocessing reactor to form at least a portion of the dispersed metal sulfide catalyst particles in situ in the heavy oil.

In other embodiments, the conditioned feedstock is heated or further heated in a hydroprocessing reactor to form at least a portion of the dispersed metal sulfide catalyst particles in situ in the heavy oil.

In some embodiments, the dispersed metal sulfide catalyst particles may be formed in a multi-step process. For example, the oil-soluble catalyst precursor composition may be premixed with a hydrocarbon diluent to form a dilute precursor mixture. Examples of suitable hydrocarbon diluents include, but are not limited to, vacuum gas oil (which typically has a nominal boiling range of 360-524°C (680-975°F)), decantate or recycle gas oil (which typically has a nominal boiling range of 360-550°C (680-1022 °F)) and gas oil (which typically has a nominal boiling range of 200-360°C (392-680°F)), some heavy petroleum feedstocks, and other hydrocarbons that nominally boil at temperatures greater than about 200°C.

The ratio of catalyst precursor to hydrocarbon petroleum diluent used to produce the dilute precursor mixture may range from about 1:500 to about 1:1, or in the range from about 1:150 to about 1:2, or in the range from about

- 12 043687

1:100 to about 1:5 (for example, 1:100, 1:50, 1:30 or 1:10).

The amount of catalytic metal (eg, molybdenum) in the dilute precursor mixture is preferably in the range of from about 100 to about 7000 ppm by weight of the dilute precursor mixture, more preferably in the range of from about 300 to about 4000 ppm by weight of the dilute precursor mixture.

The catalyst precursor is preferably mixed with a hydrocarbon diluent below a temperature at which a significant portion of the catalyst precursor composition decomposes. Mixing can be carried out at a temperature in the range of from about 25°C (77°F) to about 250°C (482°F), or in the range from about 50°C (122°F) to about 200°C (392°F ), or in the range from about 75°C (167°F) to about 150°C (302°F) to form a dilute precursor mixture. The temperature at which the dilute precursor mixture is formed may depend on the decomposition temperature and/or other characteristics of the catalyst precursor that is used and/or the characteristics of the hydrocarbon diluent, such as viscosity.

The precursor composition is preferably mixed with the hydrocarbon petroleum diluent for a period of time ranging from about 0.1 sec to about 5 min, or in the range from about 0.5 sec to about 3 min, or in the range from about 1 sec to about 1 min . The actual mixing time depends, at least in part, on temperature (ie, which affects the viscosity of the fluids) and mixing intensity. The mixing intensity depends, at least in part, on the number of stages, for example for an inline static mixer.

Premixing the catalyst precursor with the hydrocarbon diluent to form a dilute precursor mixture, which is then mixed with the heavy petroleum feedstock, greatly facilitates thorough and thorough mixing of the catalyst precursor with the feedstock, particularly in the relatively short period of time required for large-scale industrial operations. Forming a dilute precursor mixture reduces overall mixing time by (1) reducing or eliminating differences in solubility between the more polar catalyst precursor and the more hydrophobic heavy petroleum feedstock, (2) reducing or eliminating differences in rheology between the catalyst precursor and the heavy petroleum feedstock, and/ or (3) breaking down the catalyst precursor molecules to form a solute in the hydrocarbon diluent that is more readily dispersed in the heavy petroleum feedstock.

The dilute mixture of the precursor is then combined with the heavy oil feedstock and mixed for a sufficient time and in such a manner as to disperse the catalyst precursor in the feedstock to form a conditioned feedstock in which the catalyst precursor is thoroughly mixed with the heavy oil until thermal decomposition and formation of active metal sulfide catalyst species. To obtain sufficient mixing of the catalyst precursor in the heavy petroleum feedstock, the dilute mixture of the precursor and the heavy petroleum feedstock are preferably mixed for a period of time ranging from about 0.1 seconds to about 5 minutes, or in the range from about 0.5 seconds to about 3 minutes. , or in the range from about 1 s to about 3 min. Increasing the intensity and/or shear energy of the mixing process usually reduces the time required to achieve thorough mixing.

Examples of a mixing device that can be used to effect thorough mixing of the catalyst precursor and/or a dilute mixture of the precursor and heavy oil include, but are not limited to, high shear mixing such as mixing created in a propeller or turbine agitated vessel; several static built-in mixers; multiple static inline mixers combined with inline high shear mixers; multiple static inline mixers combined with high shear mixers followed by surge tank; combinations of the above followed by one or more multi-stage centrifugal pumps; and one or more multistage centrifugal pumps. In some embodiments, continuous rather than batch mixing may be accomplished using high-power pumps having multiple chambers in which the catalyst precursor composition and the heavy petroleum feedstock are mixed and mixed as part of the pumping process itself. The above mixing device can also be used for the premixing process discussed above, in which a catalyst precursor is mixed with a hydrocarbon diluent to form a catalyst precursor mixture.

In the case of a heavy petroleum feedstock that is solid or extremely viscous at room temperature, such feedstock may preferably be heated to soften it and form a feedstock having a sufficiently low viscosity to ensure good mixing of the oil-soluble catalyst precursor into the feedstock composition. Generally, lowering the viscosity of a heavy petroleum feedstock will reduce the time required to achieve thorough and uniform mixing of the oil-soluble precursor composition into the feedstock.

The heavy oil feedstock and catalyst precursor and/or dilute precursor mixture are preferably mixed at a temperature ranging from about 25° C. (77° F.) to about

- 13 043687

350°C (662°F), or in the range of about 50°C (122°F) to about 300°C (572°F), or in the range of about 75°C (167°F) to about 250° C (482°F) to obtain conditioned raw materials.

In the case where the catalyst precursor is mixed directly with the heavy petroleum feedstock without first forming a dilute precursor mixture, it may be preferable to mix the catalyst precursor and the heavy petroleum feedstock below the temperature at which a significant portion of the catalyst precursor composition is degraded. However, in the case where the catalyst precursor is premixed with a hydrocarbon diluent to form a dilute precursor mixture, which is then mixed with the heavy petroleum feedstock, it may be possible for the heavy petroleum feedstock to have a temperature at or above the decomposition temperature of the catalyst precursor. This is because the hydrocarbon diluent shields individual catalyst precursor molecules and prevents them from agglomerating to form larger particles, temporarily isolates the catalyst precursor molecules from the heat of the heavy oil during mixing, and promotes fairly rapid dispersion of the catalyst precursor molecules throughout the entire heavy oil feedstock. before decomposition releasing metal. In addition, additional heating of the feedstock may be necessary to release hydrogen sulfide from sulfur-containing molecules in the heavy oil to form metal sulfide catalyst particles. Thus, gradual dilution of the catalyst precursor allows for high levels of dispersion in the heavy petroleum feedstock, resulting in the formation of highly dispersed metal sulfide catalyst particles even when the feedstock is at a temperature above the decomposition temperature of the catalyst precursor.

After the catalyst precursor is well mixed throughout the heavy oil to form a conditioned feedstock, the composition is further heated to cause decomposition of the catalyst precursor to release the catalyst metal therefrom, cause or condition it to react with the sulfur within, and/or add to the heavy oil. oil and form active particles of the metal sulfide catalyst. The metal from the catalyst precursor may first form a metal oxide, which is then reacted with the sulfur in the heavy oil to yield a metal sulfide compound that forms the final active catalyst. Where the heavy petroleum feedstock contains sufficient or excess sulfur, the final active catalyst may be formed in situ by heating the heavy petroleum feedstock to a temperature sufficient to release the sulfur therefrom. In some cases, sulfur may be released at the same temperature at which the precursor composition decomposes. In other cases, additional heating to a higher temperature may be required.

If the catalyst precursor is thoroughly mixed throughout the heavy oil, at least a significant portion of the released metal ions will be sufficiently protected or shielded from other metal ions so that they can form a molecularly dispersed catalyst when reacting with sulfur to form a metal sulfide compound. In other circumstances, minor agglomeration may occur, resulting in colloidal size catalyst particles. However, it is believed that by thoroughly mixing the catalyst precursor throughout the feed prior to thermal decomposition of the catalyst precursor, individual catalyst molecules rather than colloidal particles can be obtained. Simple mixing without sufficient mixing of the catalyst precursor with the feed usually results in the formation of large agglomerated metal sulfide compounds that are micron in size or larger.

To form dispersed metal sulfide catalyst particles, the conditioned feedstock is heated to a temperature in the range of about 275°C (527°F) to about 450°C (842°F), or in the range of about 310°C (590°F) to about 430 °C (806°F), or in the range from about 330°C (626°F) to about 410°C (770°F).

The initial catalyst metal concentration provided by the dispersed metal sulfide catalyst particles may be in the range of from about 1 to about 500 ppm by weight of the heavy petroleum feedstock, or in the range from about 5 to about 300 ppm, or in the range from about 10 to approximately 100 ppm. The catalyst can become more concentrated as volatiles are removed from the bottoms fraction.

In the case where the heavy petroleum feedstock includes a significant amount of asphaltene molecules, the dispersed metal sulfide catalyst particles may preferentially associate with or remain in close proximity to the asphaltene molecules. Asphaltene molecules may have a greater affinity for metal sulfide catalyst particles because asphaltene molecules are generally more hydrophilic and less hydrophobic than other hydrocarbons found in heavy oil. Since metal sulfide catalyst particles tend to be very hydrophilic, individual particles or molecules will tend to migrate to the more hydrophilic moieties or molecules in the heavy petroleum feedstock.

While the highly polar nature of the metal sulfide catalyst particles causes or allows them to associate with asphaltene molecules, there is a general incompatibility between the highly polar catalyst species and the hydrophobic heavy oil, necessitating the aforementioned deep or thorough mixing of the catalyst precursor composition in the heavy oil prior to degradation and the formation of active catalyst particles. Since metal catalyst compounds are highly polar, they cannot be effectively dispersed in heavy oil when added directly to it. From a practical standpoint, the formation of smaller active catalyst particles results in a larger number of catalyst particles, which results in more evenly distributed catalyst sites throughout the heavy oil.

IV. Enriched fluidized bed reactor.

In fig. 4 schematically illustrates an example of an enriched fluidized bed hydroprocessing system 400 that can be used in the described methods and systems. The fluidized bed hydroprocessing system 400 includes an enriched fluidized bed reactor 430 and a hot separator 404 (or other separator such as a distillation column). To form enriched fluidized bed reactor 430, catalyst precursor 402 is first premixed with hydrocarbon diluent 404 in one or more mixers 406 to form catalyst precursor mixture 409. The catalyst precursor mixture 409 is added to the feed 408 and mixed with the feed in one or more mixers 410 to form the conditioned feed 411. The conditioned feed is fed to surge tank 412 with circulation pump 414 to cause further mixing and dispersion of the catalyst precursor in the conditioned feed.

The conditioned feed from the surge tank 412 is compressed by one or more pumps 416, passed through a preheater 418, and introduced into the fluidized bed reactor 430 along with compressed hydrogen gas 420 through an inlet 436 located at or near the bottom of the fluidized bed reactor 430. The heavy oil material 426 in the fluidized bed reactor 430 contains dispersed metal sulfide catalyst particles, schematically depicted as catalyst particles 424.

The heavy petroleum feedstock 408 may comprise any desired fossil fuel feedstock and/or fraction thereof, including, without limitation, one or more of the following: heavy crude oil, oil sands bitumen, crude oil bottoms, atmospheric column bottoms, bottoms vacuum column residues, coal tar, liquefied coal and other bottom fractions. In some embodiments, the heavy petroleum feedstock 408 may include a significant proportion of high-boiling hydrocarbons (i.e., nominally at or above 343°C (650°F), particularly nominally at about 524°C (975°F) or above) and/or asphaltenes. Asphaltenes are complex hydrocarbon molecules that have a relatively low ratio of hydrogen to carbon, which results from a significant number of fused aromatic and naphthenic rings with paraffinic side chains (see Fig. 1). The layers, consisting of fused aromatic and naphthenic rings, are held together by heteroatoms such as sulfur or nitrogen and/or polymethylene bridges, thioether bonds and vanadium and nickel complexes. The asphaltene cut also has higher sulfur and nitrogen contents than crude oil or other vacuum bottoms, and it also has higher concentrations of carbon-forming compounds (ie, compounds that form coke precursors and sludge).

Fluidized bed reactor 430 further includes a decompressed catalyst zone 442 containing heterogeneous catalyst 444. A lower heterogeneous catalyst free zone 448 is located below the decompressed catalyst zone 442, and an upper heterogeneous catalyst free zone 450 is located above the decompacted catalyst zone 442. The dispersed metal sulfide catalyst particles 424 are dispersed throughout the material 426 in the fluidized bed reactor 430, including the decompacted catalyst zone 442, heterogeneous catalyst free zones 448, 450, 452, thereby being available to promote enrichment reactions within what the free zones represent. catalyst in a fluidized bed reactor before enrichment with the inclusion of a dual catalytic system.

To promote hydrocracking rather than just hydrotreating reactions, the hydroprocessing reactor(s) are preferably operated at a temperature in the range of about 750°F (399°C) to about 860°F (460°C), more preferably in the range of about 780° F (416°C) to about 830°F (443°C), preferably operating at pressures in the range of about 1000 psig. inch g. (6.9 MPa) to approximately 3000 psi. inch g. (20.7 MPa), more preferably in the range of about 1500 psi. inch g. (10.3 MPa) to approximately 2500 psi. inch g. (17.2 MPa), and preferably operate at a space velocity (LHSV) in the range of from about 0.05 to about 0.45, more preferably in the range from about 0.15 to about 0.35 ^h'1 . The difference between hydrocracking and hydrotreating can also be expressed in terms of bottoms conversion rates (with hydrocracking resulting in a significant degree of conversion of higher boiling hydrocarbons to lower boiling hydrocarbons, whereas hydrotreating does not). The hydroprocessing systems described in the present invention can result in bottoms conversion ranging from about

- 15 043687 to about 90, preferably in the range from about 55 to about 80%. The preferred conversion rate range usually depends on the type of feedstock due to differences in processing complexity between different types of feedstocks. Typically, the conversion will be at least about 5, preferably at least about 10% higher than if the fluidized bed reactor was operated prior to upgrading using the dual catalyst system described herein.

The material 426 in the fluidized bed reactor 430 is continuously recirculated from the upper heterogeneous catalyst free zone 450 to the lower heterogeneous catalyst free zone 448 via a recycle channel 452 connected to an ebullation pump 454. At the top of the recirculation channel 452 is a funnel-shaped recirculation bowl 456 through which the material 426 is removed from the upper free zone 450 of the heterogeneous catalyst. Recycled material 426 is mixed with fresh conditioned feed 411 and hydrogen gas 420.

Fresh heterogeneous catalyst 444 is introduced into the fluidized bed reactor 430 through catalyst inlet tube 458, and spent heterogeneous catalyst 444 is withdrawn through catalyst outlet tube 460. While catalyst outlet tube 460 is unable to differentiate between fully spent catalyst, partially spent but active catalyst, and fresh catalyst, the existence of dispersed metal sulfide catalyst particles 424 provides additional catalytic activity in the decompressed catalyst zone 442, recycle channel 452, and bottom and top. free zones 448, 450 of the heterogeneous catalyst. The addition of hydrogen to hydrocarbons outside of the heterogeneous catalyst 444 minimizes the formation of sludge and coke precursors, which often cause deactivation of the heterogeneous catalyst.

Fluidized bed reactor 430 further includes an outlet 438 at or near the top through which converted material 440 is discharged.

The converted material 440 is introduced into a hot separator or distillation column 404. The hot separator or distillation column 404 separates one or more volatile fractions 405, which are withdrawn from the top of the hot separator 404, from a bottoms fraction 407, which is withdrawn from the bottom of the hot separator or distillation column 404. Bottoms fraction 407 contains residual metal sulfide catalyst particles, shown schematically as catalyst particles 424. If necessary, at least a portion of the bottoms fraction 407 may be recycled back to the fluidized bed reactor 430 to form a portion of the feedstock and to provide additional metal sulfide catalyst particles. Alternatively, bottoms fraction 407 may be further processed using downstream equipment, such as another fluidized bed reactor. In this case, separator 404 may be an intermediate separator.

In some embodiments, operating an enriched fluidized bed reactor for hydroprocessing a lower quality heavy petroleum feedstock or lower quality feed mixture using a dual catalyst system results in an equipment fouling rate that is equal to or less than the original operation of the fluidized bed reactor.

For example, the rate of equipment fouling during operation of an enriched fluidized bed reactor using a dual catalytic system may result in a frequency of heat exchanger cleaning shutdowns that is equal to or less than the original operation of the fluidized bed reactor, even when processing feedstocks of substandard quality.

In addition or alternatively, the rate of equipment fouling during operation of an enriched fluidized bed reactor using a dual catalyst system may result in a frequency of atmospheric and/or vacuum distillation column shutdowns for cleaning that is equal to or less than during initial reactor operation. with a fluidized bed, even in the case of processing raw materials of non-standard quality.

In addition or alternatively, the fouling rate of operating an enriched fluidized bed reactor using a dual catalyst system may result in a frequency of filter and screen replacement or cleaning that is equal to or less than that of the original fluidized bed reactor operation, even in case of processing raw materials of non-standard quality.

In addition or alternatively, the fouling rate of operating an enriched fluidized bed reactor using a dual catalytic system may result in a switching frequency to spare heat exchangers that is equal to or less than that of the original fluidized bed reactor operation, even if processing raw materials of non-standard quality.

In addition or alternatively, the rate of fouling during operation of an enriched fluidized bed reactor using a dual catalyst system may result in a lower rate of decline in shell temperatures in equipment selected from one or more heat exchangers, separators, or distillation columns than the original operation of a fluidized bed reactor, even in the case of processing raw materials of non-standard quality.

In addition or alternatively, the fouling rate during operation of an enriched fluidized bed reactor using a dual catalyst system can result in

- 16 043687 to a lower rate of increase in the temperature of the metal tubes of the furnace than during the initial operation of the fluidized bed reactor, even in the case of processing raw materials of non-standard quality.

In addition or alternatively, the fouling rate of operating an enriched fluidized bed reactor using a dual catalyst system may result in a lower rate of increase in the design fouling tolerance factors for heat exchangers than the original operation of the fluidized bed reactor, even if processing raw materials of non-standard quality.

In some embodiments, operation of an enriched fluidized bed reactor using a dual catalyst system may result in sludge formation rates that are equal to or less than the original operation of the fluidized bed reactor, even when processing substandard feedstocks. In some embodiments, the fouling rate may be calculated based on measuring the fouling in one or more of: (1) the atmospheric column bottoms product; (2) vacuum column bottom product; (3) product from the low pressure hot separator; or (4) a liquid fuel product before or after the addition of diluents.

In some embodiments, operation of an enriched fluidized bed reactor using a dual catalyst system may result in a product sludge concentration that is equal to or less than the original operation of the fluidized bed reactor, even when processing feedstocks of substandard quality. In some embodiments, the product sludge concentration may be calculated based on sludge measurements in one or more of: (1) the atmospheric distillation residue product fraction and/or the atmospheric column bottoms product; (2) fractions of the vacuum distillation residue product and/or vacuum column bottoms product; (3) material fed into the atmospheric column; (4) product from the low pressure hot separator; or (5) a liquid fuel product before or after the addition of one or more diluents.

V. Experimental studies and results.

The following experimental study demonstrates the effects and benefits of fluidized bed reactor enrichment for the use of a dual catalyst system consisting of a heterogeneous catalyst and dispersed metal sulfide catalyst particles in the hydroprocessing of heavy oil, especially substandard feedstocks.

The pilot plant used for this test is designed according to FIG. 5. As schematically shown in FIG. 5, a pilot plant 500 with two fluidized bed reactors 512, 512' connected in series was used to determine the difference between the use of a single heterogeneous catalyst in the processing of heavy petroleum feedstocks and a dual catalyst system consisting of a heterogeneous catalyst in combination with dispersed metal sulfide catalyst particles (i.e. dispersed molybdenum disulfide catalyst particles).

For the following experimental studies, heavy vacuum gas oil was used as a hydrocarbon diluent. The precursor mixture was prepared by mixing an amount of the catalyst precursor with an amount of hydrocarbon diluent to form a catalyst precursor mixture and then mixing an amount of the catalyst precursor mixture with an amount of the heavy petroleum feedstock to achieve a target loading level of dispersed catalyst in the conditioned feedstock. As a specific illustration, for one experimental study with a target loading of 30 ppm of dispersed metal sulfide catalyst in the conditioned feed (where the loading is expressed per metal concentration), the catalyst precursor mixture was prepared at a metal concentration of 3000 ppm.

The feedstock and operating conditions for the performance tests are described in more detail below. The heterogeneous catalyst was a commercially available catalyst typically used in fluidized bed reactors. It should be noted that for comparative experimental studies for which a dispersed metal sulfide catalyst was not used, a hydrocarbon diluent (heavy vacuum gas oil) was added to the heavy petroleum feedstock in the same ratio as when using the dilute precursor mixture. This ensured that the background composition was the same in tests using the dual catalyst system and in tests using only a single (fluidized bed) heterogeneous catalyst, allowing test results to be directly compared.

The pilot plant 500 more specifically included a high shear mixing vessel 502 used to mix a precursor mixture consisting of a hydrocarbon diluent and a catalyst precursor (e.g., molybdenum-2-ethylhexanoate) with the heavy petroleum feedstock (collectively indicated at 501) to formation of conditioned raw materials. Proper mixing can be achieved by first premixing the catalyst precursor with the hydrocarbon diluent to form the precursor mixture.

The conditioned feedstock was recycled back and forth to the mixing vessel 502 using pump 504, similar to the use of a surge tank and circulation pump. High

- 17 043687 a 506 precision positive displacement piston pump sucked conditioned feed from the recirculation loop and compressed it to reactor pressure. Hydrogen gas 508 is supplied to the compressed feed and the resulting mixture passes through a preheater 510 before being introduced into the first fluidized bed reactor 512. Preheater 510 may cause at least a portion of the catalyst precursor in the conditioned feed to decompose and form active catalyst species in situ in the feed.

Each of the fluidized bed reactors 512, 512' may have a nominal internal volume of approximately 3000 ml and may include a mesh wire casing 514 to contain the heterogeneous catalyst in the reactor. Each reactor is also equipped with a recycle line and a recycle pump 513, 513', which provides the required flow rate in the reactor to decompact the heterogeneous catalyst bed. The combined volume of both reactors and their respective recycle lines, all of which are maintained at a given reactor temperature, can be considered the thermal reaction volume of the system and can be used as the basis for calculating the liquid hourly space velocity (LHSV). For these examples, LHSV is defined as the volume of vacuum residue feed fed to the reactor per hour divided by the thermal reaction volume.

The height of the deposited catalyst bed in each reactor is shown schematically by the lower dashed line 516, and the decompacted catalyst bed in use is shown schematically by the upper dashed line 518. A recirculation pump 513 was used to recirculate the processed material from the top to the bottom of the reactor 512 to maintain a stable upward flow of material. and decompaction of the catalyst layer.

The enriched material from the first reactor 512 was transported along with additional hydrogen 520 to the second reactor 512' for additional hydroprocessing. A second recirculation pump 513' was used to recirculate the processed material from the top to the bottom of the second reactor 512' to maintain a stable upward flow of material and decompact the catalyst bed.

Further enriched material from the second reactor 512' is introduced into the first hot separator 522 to separate low boiling point hydrocarbon product vapors and gases 524 from the liquid fraction 526 consisting of unconverted heavy oil. The hydrocarbon product vapors and gases 524 are cooled and enter a cold separator 528, where they are separated into gases 530 and converted hydrocarbon products, which are recovered as a separator overhead 532. The liquid fraction 526 from the hot separator 522 is recovered as a separator bottoms product 534, which can be used for analysis.

Examples 1-3.

Examples 1-3 were carried out in the above pilot plant and tested the ability of an enriched fluidized bed reactor, which used a dual catalyst system consisting of a heterogeneous catalyst and dispersed metal sulfide catalyst particles, to allow the use of substandard quality feedstocks while maintaining the rate of production of converted products , as well as maintaining or reducing sediment formation. The rate of formation of converted products is related to bottoms conversion, _C7 asphaltenes conversion, and microcarbon residue (MCR) conversion. The original heavy petroleum feedstock used in this study was Arab Medium Vacuum Residue (VR), and the substandard quality feedstock was Urals Vacuum Residue (VR), which was of significantly lower quality compared to Arab Medium VR. As described above, the conditioned feedstock was prepared by mixing an amount of the catalyst precursor mixture with an amount of the heavy petroleum feedstock to produce a final conditioned feedstock that contained the desired amount of dispersed catalyst. In addition to these tests, tests were conducted in which the dispersed catalyst was not used, in which case the heavy vacuum gas oil was replaced by a catalyst precursor mixture in the same ratio.

The conditioned feedstock was supplied to the pilot plant system of FIG. 5, which worked using certain parameters. The corresponding conditions and results of the process are presented in table. 1.

- 18 043687

Table 1

Example No. 1 2 3 Raw materials 100% Arab Medium VR 80% Arab Medium VR/ 20% Urals VR 80% Arab Medium VR/ 20% Urals VR Dispersed concentration catalyst 0 0 50 Reactor temperature, °F (°C) 815 (435) 815 (435) 815 (435) LHSV, vol. raw materials/vol. reactor/h 0.25 0.25 0.25 Bottoms conversion based on 1000°F+ (538°C+), % 80% 82% 79% Sediment in products, IP-375, bottom products of separator, wt.% 0.80% 1.16% 0.24% Sediment in products, IP-375, petroleum feedstock, wt.% 0.53% 0.78% 0.17% Conversion C ₇ asphaltenes, % 66% 68% 74% MCR conversion, % 56% 61% 63%

Examples 1 and 2 used a heterogeneous catalyst to simulate a fluidized bed reactor prior to upgrading using the dual catalyst system of the invention. Example 3 used a dual catalyst system consisting of the same heterogeneous catalyst of Examples 1 and 2, as well as dispersed molybdenum sulfide catalyst particles. The concentration of dispersed molybdenum sulfide catalyst particles in the feed was defined as the concentration in parts per million (ppm) of molybdenum metal (Mo) provided by the dispersed catalyst. The feeds of Examples 1 and 2 contained no dispersed catalyst (0 ppm Mo), and the feeds of Example 3 contained dispersed catalyst at a concentration of 50 ppm Mo.

Example 1 was a baseline test using 100% Arab Medium VR as the heavy oil feedstock. The heavy petroleum feedstock was hydroprocessed at 815°F (435°C) with bottoms conversion (assuming 1000°F+, in %) of 80%, sediment in IP-375 products (for separator bottoms, in wt. %) 0.80%, sediment in products according to IP-375 (for petroleum feedstock, in wt.%) 0.53%, conversion of C ₇ asphaltenes 66% and conversion of microcarbon residue (MCR) 56%.

In Example 2, a sub-standard feedstock (Urals VR) was mixed with Arab Medium VR at 20% to produce a lower quality heavy petroleum feedstock blend of 80% Arab Medium VR and 20% Urals VR. Reactor temperature was maintained at 815°F (435°C) with bottoms conversion (assuming 1000°F+, in %) of 82%, sediment in products to IP-375 (for bottoms separator product, in wt.%) 1 .16%, sediment in products according to IP-375 (for petroleum feedstock, in wt.%) 0.78%, C ₇ asphaltenes conversion 68% and microcarbon residue conversion (MCR) 61%. While the amount of converted products increased slightly, sediment formation increased to a much greater extent. Thus, operating a fluidized bed reactor using the same heterogeneous catalyst as Example 1 to hydrotreat a lower quality heavy petroleum feedstock mixture containing substandard feedstock would require operation under less stringent conditions to maintain the same level sediment formation and the rate of equipment contamination. Operating under less stringent conditions when hydroprocessing a mixture of lower quality heavy petroleum feedstocks containing substandard feedstocks would result in a reduction in the rate of formation of converted products. This shows that a traditional fluidized bed reactor using a heterogeneous catalyst alone is not capable of hydroprocessing substandard feedstocks while maintaining or increasing the rate of conversion of converted products without generating significantly more equipment-contaminating sludge.

In Example 3, the same lower quality heavy petroleum feedstock mixture of 80% Arab Medium VR and 20% Urals VR (substandard feedstock) used in Example 2 was hydroprocessed using a dual catalyst system consisting of a heterogeneous catalyst Examples 1 and 2 and dispersed metal sulfide catalyst particles yielding 50 ppm molybdenum (Mo) metal. The reactor temperature was maintained at 815°F

- 19 043687 (435°C) with bottoms conversion (based on 1000°F+, in %) 79%.

Compared to example 2, the use of a dual catalyst system instead of a heterogeneous catalyst sharply reduced sediment in products according to IP-375 (for the bottom product of the separator, in wt.%) from 1.16 to 0.24%, sharply reduced sediment in products according to IP -375 (for petroleum feedstock, in wt.%) from 0.78 to 0.17%, increased the conversion of C ₇ asphaltenes from 68% to 74% and increased the conversion of MCR from 61 to 63%. This clearly demonstrates the advantage of using a dual catalyst system when hydroprocessing heavy petroleum feedstocks or lower quality feedstocks in a fluidized bed reactor compared to using a heterogeneous catalyst alone.

The use of the dual catalyst system in Example 3 also resulted in a significant reduction in sludge formation and a significant increase in C ₇ asphaltenes conversion and MCR conversion compared to Example 1, which used a higher quality heavy oil feedstock. Despite the fact that in example 3 hydroprocessing of a feed mixture of lower quality was carried out compared to the higher quality feedstock in example 1, the use of a dual catalytic system nevertheless led to a sharp reduction in sediment in products according to IP-375 (for the bottom product of the separator, in wt.%) from 0.80 to 0.24% and to a sharp decrease in sediment in products according to IP-375 (for petroleum feedstock, in wt.%) from 0.53 to 0.17%, with a simultaneous increase in C conversion ₇ asphaltenes from 66 to 74% and an increase in MCR conversion from 56 to 63%. This further demonstrates the advantage of using a dual catalyst system when hydroprocessing heavy petroleum feedstocks or lower quality feedstocks in a fluidized bed reactor compared to using a heterogeneous catalyst alone.

Examples 4, 5.

Examples 4, 5 compared the effect of using a heterogeneous catalyst alone in a fluidized bed hydroprocessing system with a dual catalyst system that included the same heterogeneous catalyst and dispersed metal sulfide catalyst particles in hydroprocessing a mixed feedstock containing substandard feedstock while maintaining the same degree of residue conversion. The base heavy petroleum feedstock used in this study was Vacuum Residue (VR), designated SEG-17, and the substandard feedstock was Urals Vacuum Residue (VR), which was of substantially lower quality than SEG-17. The mixed heavy oil feedstock contained 80% SEG-17 and 20% Urals VR. The corresponding process conditions and results are presented in table. 2.

table 2

Example No. 4 5 Raw materials 80% SEG-17/ 20% Urals VR 80% SEG-17/ 20% Urals VR Catalyst used only heterogeneous catalyst dual catalytic system Balance conversion, May. % 75 75 Conversion C ₇ 57.6% 70.1% asphaltenes,% Sediment in ATV, IP-375, wt.% 1.20% 0.23% VTB Density in API degrees, ° -3.0 0.9 Desulfurization, May. % 79.2% 81.1% Viscosity VTB at 300°F (149°C), cP 380 146 CCR conversion, wt.% 51.3% 59.1%

Example 4 used a heterogeneous fluidized bed catalyst and was the base case against which the performance of a dual catalyst system was compared. In example 5, a dual catalyst system was used, consisting of the heterogeneous catalyst of example 4, as well as dispersed molybdenum sulfide catalyst particles. Both examples 4 and 5 were performed at the same residue conversion of 75% wt. to make a reliable comparison.

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Claims (23)

As shown in table. 2, the use of the dual catalyst system in Example 5 instead of the heterogeneous catalyst alone in Example 4 increased the conversion of C ₇ asphaltenes from 57.6 to 70.1%, which is expected to significantly reduce fouling and sludge formation and better maintain reactor stability. This was confirmed by a reduction in sludge in IP-375 ATB from 1.20 to 0.23% when using a dual catalyst system instead of a heterogeneous catalyst alone. In addition, the use of a dual catalyst system in Example 5 instead of the heterogeneous catalyst used alone in Example 4 increased VTB density from 3.0°API to 0.9°API, increased desulfurization from 79.2 to 81.1 wt. .%, decreased VTB viscosity at 300°F (149°C) from 380 to 146 cP, and increased CCR conversion from 51.3 to 59.1 wt.%. Example 6. Example 6 used the same mixture of base and custom feedstocks (80% SEG17/20% Urals VTB) as Examples 4-5 and compared asphaltene conversion at various time intervals in an industrial continuous hydroconversion unit using a fluidized bed separately a taken heterogeneous catalyst and a double catalytic system consisting of a fluidized bed of a heterogeneous catalyst and dispersed particles of a molybdenum sulfide catalyst. The results are shown in Fig. 6, which shows a graph of asphaltene conversion at various time intervals using different catalytic systems. As can be clearly seen in FIG. 6, the use of a dual catalyst system led to a significant increase in asphaltene conversion compared to the use of a heterogeneous catalyst alone. Example 7. Example 7 used different non-standard quality feedstocks and compared the % wt. sludge when using a fluidized bed of a single heterogeneous catalyst or a dual catalytic system consisting of a fluidized bed of a heterogeneous catalyst and dispersed molybdenum sulfide catalyst particles. The substandard raw materials used in this example were vacuum residues identified as Urals, Eugene Island, Ras Gharib and Isthmus. The results are shown in Fig. 7, which shows a graph of % wt., sediment at various time intervals when using various raw materials of non-standard quality, both with and without dispersed molybdenum sulfide catalyst particles. As can be clearly seen in FIG. 7, the use of a dual catalyst system that contained both a heterogeneous catalyst and dispersed molybdenum sulfide catalyst particles resulted in a significant reduction in sludge formation for each substandard feedstock compared to use of the heterogeneous catalyst alone. Example 8. Example 8 compared the effects of using a dual catalyst system versus a heterogeneous catalyst alone on a vacuum tower bottoms (VTB) heat exchanger, which directly affects the heat load of the heat exchanger. The fluidized bed reactor was initially operated with the heterogeneous catalyst alone at low feed rates and reactor temperatures. Fouling of the VTB heat exchanger reduced the heat load of the heat exchanger, after which cleaning was necessary. Normal plant operation was resumed at maximum feed rates and normal reactor temperatures, resulting in a sustained reduction in heat exchanger load or increased fouling of the VTB heat exchanger, necessitating cleaning. After introducing dispersed molybdenum sulfide catalyst particles to form a dual catalyst system, the heat exchanger load stabilized, indicating a reduction in VTB heat exchanger fouling. Once the heat exchanger load stabilized to a constant level, the use of the dispersed molybdenum sulfide catalyst particles was stopped and, when the heterogeneous catalyst alone was used again, the heat exchanger load decreased, indicating renewed fouling of the VTB heat exchanger. The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not limiting. Accordingly, the scope of the invention is determined by the appended claims and not by the preceding description. All changes that fall within the spirit and range of equivalence of the claims are to be considered included within the scope of the invention. CLAIM 1. A method for upgrading a fluidized bed hydroprocessing system that contains one or more fluidized bed reactors for hydroprocessing lower quality heavy oil, comprising: initial introduction of a heavy petroleum feedstock into a fluidized bed reactor during initial operation of a fluidized bed reactor using a heterogeneous catalyst for hydroprocessing of a heavy petroleum feedstock under initial conditions of reactor severity, initial conversion rate of hydrocarbon products, and initial equipment fouling rate , where the initial heavy oil feedstock is characterized by the initial quality and the initial reactor severity conditions are characterized by the initial operating temperature, the initial throughput of the heavy oil feedstock and the initial conversion of heavy oil; upgrading the fluidized bed reactor to operate using a dual catalyst system consisting of dispersed metal sulfide catalyst particles and a heterogeneous catalyst after initially operating the fluidized bed reactor using the heterogeneous catalyst; characterized in that after upgrading the fluidized bed reactor for operation using a dual catalytic system, a lower quality heavy oil feedstock is introduced into the enriched fluidized bed reactor instead of the original heavy oil feedstock and an enriched fluidized bed reactor using a dual catalytic system for hydroprocessing the heavy oil lower quality petroleum feedstock is operated at the same or higher reactor hardness relative to the initial reactor hardness by: increasing the operating temperature by at least 2.5°C compared to the initial operating temperature, and maintaining or increasing the throughput relative to the original throughput, and maintaining or increasing the rate of formation of converted hydrocarbon products relative to the initial rate of formation of converted products, and without increasing the rate equipment contamination relative to the initial equipment contamination rate, at initial operation, of the fluidized bed reactor at initial conditions, enrichment of the fluidized bed reactor to operate the reactor under harsh conditions and at a rate of conversion of converted products, which provides the following of: (i) increased asphaltene conversion, (ii) reduced sediment in the atmospheric column bottoms (ATB), (iii) increased micro carbon conversion (MCR), (iv) increased API gravity in the vacuum column bottoms (VTB), (v) increased desulfurization, (vi) ) reduced VTB viscosity or (v) increased CCR conversion compared to original fluidized bed reactor operation, where operation of the enriched fluidized bed reactor at reactor severity and rate of conversion of converted products causes an equipment fouling rate characterized by at least one of: a frequency of heat exchanger shutdowns for cleaning that is equal to or less than during the original operation of the fluidized bed reactor; a frequency of shutdowns of the atmospheric and/or vacuum distillation column for purification that is equal to or less than the initial operation of the fluidized bed reactor; a frequency of replacement or cleaning of filters and screens that is equal to or less than during the original operation of the fluidized bed reactor; frequency of switching to spare heat exchangers, which is equal to or less than during the initial operation of the fluidized bed reactor; a lower rate of decline in shell temperatures in equipment selected from one or more heat exchangers, separators or distillation columns than during the original operation of the fluidized bed reactor; a lower rate of increase in the temperature of the metal pipes of the furnace than during the initial operation of the fluidized bed reactor; or a lower rate of increase in the design fouling tolerance factors for the heat exchangers than for the original fluidized bed reactor operation, and where the lower quality heavy oil feedstock is characterized as having a greater tendency to form sludge than the original quality heavy oil feedstock and having, at least one additional lower quality characteristic of the following lower quality characteristics compared to the original quality heavy oil feedstock: higher boiling point; higher sulfur concentration; higher nitrogen concentration; higher concentration of metals; higher molecular weight; higher viscosity; higher density; lower hydrogen to carbon ratio; or higher asphaltene content. 2. The method of claim 1, wherein the lower quality heavy oil feedstock is characterized as having a higher asphaltene content than the heavy oil feedstock, and, according to - 22 043687 at least one other lower quality, selected from: higher boiling point than that of the original heavy oil feedstock; higher sulfur concentration than the original heavy oil feedstock; higher nitrogen concentration than the original heavy oil feedstock; higher concentration of metals than the original heavy oil feedstock; higher molecular weight than the original heavy petroleum feedstock; and a lower hydrogen to carbon ratio than the heavy petroleum feedstock. 3. The method according to claim 1 or 2, wherein the lower quality heavy oil feedstock is a mixture of lower quality heavy oil feedstocks containing the original heavy oil feedstock or heavy oil of comparable quality and at least 20, or at least at least 30%, or at least 40 wt.% heavy oil of lower quality. 4. The method according to any one of claims 1 to 3, wherein the starting heavy oil of lower quality is a heavy petroleum feedstock. 5. The method according to any one of claims 1 to 4, wherein the original heavy oil feedstock and the lower quality heavy oil feedstock contain at least one of heavy crude oil, oil sands bitumen, refinery process residues, atmospheric column bottoms, having a nominal boiling point of at least 343°C (650°F), vacuum column bottoms having a nominal boiling point of at least 524°C (975°F), hot separator bottoms, pitch, bottoms solvent extraction or vacuum residues. 6. The method according to any one of claims 1 to 5, in which the operation of an enriched fluidized bed reactor using a dual catalytic system for hydroprocessing of lower quality heavy petroleum feedstocks is characterized by reactor severity and the rate of formation of converted products, which reduce the rate of equipment fouling, according to compared to the original operation of the fluidized bed reactor. 7. The method according to claim 6, in which the rate of equipment contamination is characterized by at least one of: the frequency of heat exchanger stops for cleaning, which is less than during the initial operation of the fluidized bed reactor; the frequency of shutdowns of the atmospheric or vacuum distillation column for cleaning, which is less than during the initial operation of the fluidized bed reactor; the time required to replace or clean filters and screens, which is less than during the initial operation of the fluidized bed reactor; the frequency of switching to spare heat exchangers, which is less than during the initial operation of the fluidized bed reactor; a lower rate of decrease in shell temperatures in equipment selected from one or more heat exchangers, separators or distillation columns than during the original operation of the fluidized bed reactor; a lower rate of increase in the temperature of the metal pipes of the furnace than during the initial operation of the fluidized bed reactor; or a lower rate of increase in the design fouling tolerance factors for the heat exchangers than for the original fluidized bed reactor operation. 8. The method according to any one of claims 1 to 7, wherein the operation of an enriched fluidized bed reactor using a dual catalytic system for the hydroprocessing of lower quality heavy petroleum feedstocks is characterized by reactor severity and the rate of formation of converted products that maintain or reduce the rate of sludge formation compared to the original operation of the fluidized bed reactor. 9. The method according to claim 8, in which the rate of sediment formation is determined by at least: determination of sediment in the bottom product of the atmospheric column; determination of sediment in the bottom product of a vacuum column; determination of sediment in the product of a low pressure hot separator; or determination of sediment in a liquid fuel product before or after the addition of diluents. 10. The method according to any one of claims 1 to 9, wherein the operation of an enriched fluidized bed reactor using a dual catalytic system for the hydroprocessing of lower quality heavy petroleum feedstocks is characterized by the severity of the reactor and the rate of formation of converted products that maintain or reduce the concentration of sludge in product, compared to the original operation of the fluidized bed reactor. 11. The method according to claim 10, in which the concentration of sediment in the product is determined at least as follows: determination of sediment in the bottom product of the atmospheric column; determination of sediment in the bottom product of a vacuum column; determination of sediment in the product of a low pressure hot separator; determination of sediment in a liquid fuel product before or after the addition of one or more diluents. - 23 043687 12. The method according to any one of claims 1 to 11, in which the dispersed particles of the metal sulfide catalyst have a size of less than 1 μm, or less than 500 nm, or less than 100, or less than 25, or less than 10 nm. 13. The method according to any one of claims 1 to 12, wherein the dispersed metal sulphide catalyst particles are formed in situ in the heavy oil from the catalyst precursor. 14. The method of claim 13, wherein forming the metal sulfide catalyst particles in situ comprises first mixing the catalyst precursor with a hydrocarbon diluent to form a dilute mixture of the precursor, then mixing the dilute mixture of the precursor with a heavy oil to form a conditioned heavy oil, and then heating the conditioned heavy oil to decompose the catalyst precursor and form dispersed metal sulfide catalyst particles in situ. 15. The method according to any one of claims 1 to 14, wherein the operation of an enriched fluidized bed reactor using a dual catalytic system for the hydroprocessing of lower quality heavy petroleum feedstocks is characterized by an increased reactor stiffness compared to the initial reactor stiffness selected by at least , one of two: operation of an enriched fluidized bed reactor at an increased degree of heavy oil conversion compared to operation of the original fluidized bed reactor; operation of an enriched fluidized bed reactor at increased heavy oil throughput compared to operation of the original fluidized bed reactor; operation of an enriched fluidized bed reactor at an elevated temperature compared to operation of the original fluidized bed reactor. 16. The method according to claim 15, in which the operation of the enriched fluidized bed reactor with increased conversion of heavy oil is characterized by an increase in the conversion of heavy oil by at least 1, at least 5, at least 10 or at least 10 , 15% compared to the operation of the original fluidized bed reactor. 17. The method according to claim 15 or 16, in which the operation of the enriched fluidized bed reactor with increased heavy oil throughput is characterized by an increase in heavy oil throughput by at least 2.5, at least 5, at least, 10, or at least 15, or at least 20% compared to the operation of the original fluidized bed reactor. 18. The method according to any one of claims 15-17, in which the operation of the enriched fluidized bed reactor at an elevated temperature is characterized by an increase in the temperature of the enriched fluidized bed reactor by at least 2.5, at least 5, at least , 7.5, or at least 10, or at least 15°C compared to operation under initial conditions. 19. A method for upgrading a fluidized bed hydroprocessing system for hydroprocessing lower grade heavy oil, comprising: the initial introduction of a heavy petroleum feedstock of the original quality into a fluidized bed reactor during the initial operation of a fluidized bed reactor using a heterogeneous catalyst for hydroprocessing of the heavy petroleum feedstock at the initial reactor severity conditions, and the initial rate of formation of hydrocarbon converted products, where the initial reactor severity conditions characterized by an initial operating temperature, an initial heavy oil throughput, an initial heavy oil conversion rate, and an initial equipment fouling rate, and where the initial heavy oil feedstock has an initial quality characterized by at least asphaltenes content; upgrading the fluidized bed reactor to operate using a dual catalyst system consisting of dispersed metal sulfide catalyst particles and a heterogeneous catalyst after initially operating the fluidized bed reactor using the heterogeneous catalyst; characterized in that after upgrading the fluidized bed reactor for operation using a dual catalytic system, heavy oil feedstock of lower quality is introduced into the enriched fluidized bed reactor instead of the original heavy oil feedstock and the enriched fluidized bed reactor using a dual catalyst system for hydroprocessing of heavy oil Lower quality feedstocks operate at higher reactor stringency conditions by: increasing the operating temperature by at least 2.5°C compared to the initial operating temperature, and maintaining and increasing the throughput of heavy oil compared to the initial initial throughput, increasing the rate of formation of converted hydrocarbon products compared to the initial rate of formation of converted products, and without increasing the equipment fouling rate relative to the original equipment fouling rate, at the original operation, of the fluidized bed reactor at the original conditions, enrichment of the fluidized bed reactor to operate the reactor under severe conditions and at the rate of formation of converted products, which provides the following of: (i) increased asphaltene conversion, (ii) reduced sediment in the atmospheric column bottoms (ATB), (iii) increased - 24 043687 MCR conversion, (iv) increased API gravity in vacuum column bottoms (VTB), (v) increased desulfurization, (vi) reduced VTB viscosity, or (v) increased conversion CCR compared to original fluidized bed reactor operation, where operation of the enriched fluidized bed reactor at reactor severity and conversion rate produces an equipment fouling rate characterized by at least one of: a frequency of heat exchanger shutdowns for cleaning that is equal to or less than during the original operation of the fluidized bed reactor; a frequency of shutdowns of the atmospheric and/or vacuum distillation column for purification that is equal to or less than the initial operation of the fluidized bed reactor; a frequency of replacement or cleaning of filters and screens that is equal to or less than during the original operation of the fluidized bed reactor; frequency of switching to spare heat exchangers, which is equal to or less than during the initial operation of the fluidized bed reactor; a lower rate of decline in shell temperatures in equipment selected from one or more heat exchangers, separators or distillation columns than during the original operation of the fluidized bed reactor; a lower rate of increase in the temperature of the metal pipes of the furnace than during the initial operation of the fluidized bed reactor; or a slower rate of increase in design fouling tolerance factors for heat exchangers than for original fluidized bed reactor operation, with lower quality heavy oil feedstocks having higher asphaltene content and a greater tendency to form deposits compared to the asphaltene content of the base-based feedstock. heavy oil of original quality. 20. A method for upgrading a fluidized bed hydroprocessing system for hydroprocessing lower quality heavy oil, comprising: the initial introduction of an original quality heavy petroleum feedstock into a fluidized bed reactor during the initial operation of a fluidized bed reactor using a heterogeneous catalyst for hydroprocessing of an original quality heavy petroleum feedstock, under initial operating conditions including initial reactor severity conditions, initial conversion rate of hydrocarbons products and the initial rate of equipment fouling and/or sludge formation, where the initial reactor severity conditions are characterized by the initial operating temperature, the initial heavy oil throughput and the initial heavy oil conversion; enrichment of a fluidized bed reactor for operation using a dual catalyst system consisting of dispersed particles of a metal sulfide catalyst and a heterogeneous fluidized bed catalyst after initial operation of the fluidized bed reactor using a heterogeneous catalyst, characterized in that after enrichment of the fluidized bed reactor for operation using dual catalyst system introduces a mixture of lower quality heavy oil feedstock into the enriched fluidized bed reactor instead of the original heavy oil feedstock, and an enriched fluidized bed reactor using a dual catalyst system to hydrotreat the lower quality heavy oil feedstock mixture operates at the same or higher high reactor rigidity by: increasing the operating temperature by at least 2.5°C compared to the initial operating temperature, and maintaining and increasing the throughput compared to the original throughput; maintaining or increasing the rate of formation of converted products compared to the initial rate of formation of converted products, and without increasing the rate of equipment fouling and/or sludge formation compared to the initial rate of equipment fouling and/or sludge formation, during the initial operation, of the fluidized bed reactor at the initial operating conditions, enrichment of the fluidized bed reactor to operate the reactor under harsh conditions and at a conversion rate that provides the following of: (i) increased asphaltene conversion, (ii) reduced sediment in the atmospheric column bottoms (ATB), (iii) increased MCR conversion, (iv) increased API gravity in vacuum column bottoms (VTB), (v) increased desulfurization, (vi) reduced VTB viscosity, or (v) increased CCR conversion compared to original fluidized bed reactor operation, where the operation of an enriched fluidized bed reactor at reactor rigidity and the rate of formation of converted products causes a rate of equipment contamination characterized by at least one of: a frequency of heat exchanger shutdowns for cleaning that is equal to or less than during the original operation of the fluidized bed reactor; - 25 043687 frequency of shutdowns of the atmospheric and/or vacuum distillation column for cleaning, which is equal to or less than during the initial operation of the fluidized bed reactor; a frequency of replacement or cleaning of filters and screens that is equal to or less than during the original operation of the fluidized bed reactor; frequency of switching to spare heat exchangers, which is equal to or less than during the initial operation of the fluidized bed reactor; a lower rate of decline in shell temperatures in equipment selected from one or more heat exchangers, separators or distillation columns than during the original operation of the fluidized bed reactor; a lower rate of increase in the temperature of the metal pipes of the furnace than during the initial operation of the fluidized bed reactor; or a lower rate of increase in the design fouling tolerance factors for the heat exchangers than for the original fluidized bed reactor operation, the lower quality feed mixture being characterized as containing a mixture of the original quality heavy oil feedstock, or heavy oil of similar quality, and from 5 to 90% heavy oil lower quality oil, wherein the lower quality heavy oil is characterized by a greater propensity to form deposits than the original heavy oil feedstock and additionally at least one lower quality indicator compared to the original heavy oil feedstock selected from : higher boiling point, higher sulfur content, higher nitrogen content, higher metal content, higher molecular weight, higher viscosity, higher density, lower hydrogen to carbon ratio and higher asphaltene content. 21. The method according to claim 19, wherein the lower quality feed mixture contains at least 10, or at least 20, or at least 30, or at least 40% heavy oil more Low quality. 22. A method for upgrading a fluidized bed hydroprocessing system for hydroprocessing lower quality heavy oil, comprising: the initial introduction of an original quality heavy oil feedstock into a fluidized bed reactor during the initial operation of a fluidized bed reactor using a heterogeneous catalyst for hydroprocessing of an original quality heavy oil feedstock under initial operating conditions, including the initial reactor severity conditions, the initial rate of formation of converted hydrocarbon products and the initial rate of equipment fouling and/or sludge formation, where the initial reactor severity conditions are characterized by the initial operating temperature, the initial heavy oil throughput and the initial heavy oil conversion; enrichment of a fluidized bed reactor for operation using a dual catalyst system consisting of dispersed particles of a metal sulfide catalyst and a heterogeneous fluidized bed catalyst after initial operation of the fluidized bed reactor using a heterogeneous catalyst, characterized in that after enrichment of the fluidized bed reactor for operation using dual catalyst system introduces lower quality heavy oil feedstock into the enriched fluidized bed reactor instead of the original heavy oil feedstock and the enriched fluidized bed reactor using dual catalyst system to hydrotreat lower quality heavy oil operates at higher reactor stringency conditions by: increasing the operating temperature by at least 2.5°C compared to the initial operating temperature, and maintaining and increasing the heavy oil throughput compared to the initial throughput, and increasing the rate of formation of converted products compared to the initial rate of formation of converted products, and without increasing the rate of equipment contamination and/or sediment formation compared to the initial contamination rate; equipment and/or sludge formation, when operating the fluidized bed reactor at the original operating conditions, enrichment of the fluidized bed reactor to operate the reactor under harsh conditions and at a conversion rate that provides the following of: (i) increased asphaltene conversion, (ii ) reduced sludge in the atmospheric column bottoms (ATB), (iii) increased MCR conversion, (iv) increased API gravity in the vacuum column bottoms (VTB), (v) increased desulfurization, (vi) reduced VTB viscosity or ( v) increased CCR conversion compared to the original operation of the fluidized bed reactor, where the operation of the enriched fluidized bed reactor at the reactor severity and the rate of formation of converted products causes an equipment fouling rate characterized by - 26 043687 at least one of: a frequency of heat exchanger shutdowns for cleaning that is equal to or less than during the original operation of the fluidized bed reactor; a frequency of shutdowns of the atmospheric and/or vacuum distillation column for purification that is equal to or less than the initial operation of the fluidized bed reactor; a frequency of replacement or cleaning of filters and screens that is equal to or less than during the original operation of the fluidized bed reactor; frequency of switching to spare heat exchangers, which is equal to or less than during the initial operation of the fluidized bed reactor; a lower rate of decline in shell temperatures in equipment selected from one or more heat exchangers, separators or distillation columns than during the original operation of the fluidized bed reactor; a lower rate of increase in the temperature of the metal pipes of the furnace than during the initial operation of the fluidized bed reactor; or a lower rate of increase in the design fouling tolerance factors for the heat exchangers than in the original fluidized bed reactor operation, where the lower quality heavy oil feedstock is more prone to fouling than the original quality heavy oil feedstock, and additionally, at least one lower quality characteristic compared to the original petroleum feedstock, selected from: higher boiling point, higher sulfur content, higher nitrogen content, higher metal content, higher molecular weight, higher viscosity, higher density, lower ratio hydrogen to carbon, and higher asphaltene content. 23. A method for improved hydroprocessing of heavy oil using a fluidized bed hydroprocessing system for hydroprocessing heavy oil of lower quality compared to a conventional fluidized bed system under appropriate operation, comprising: providing a fluidized bed reactor designed to use a heterogeneous catalyst for the hydroprocessing of heavy oil, and which, when properly operated, is capable of stable operation in the hydroprocessing of heavy oil of a base level of quality, under base conditions including base conditions of reactor severity, base rate of formation of converted carbon products and base equipment fouling rate, where base reactor severity conditions are characterized by base operating temperature, base heavy oil throughput and base heavy oil conversion; enhancing the hydroprocessing of heavy oil by a fluidized bed reactor by introducing a dual catalyst system consisting of dispersed particles of a metal sulfide catalyst and a heterogeneous catalyst into the fluidized bed reactor together with heavy oil and hydrogen; characterized in that after upgrading the fluidized bed reactor for operation using a dual catalytic system, a lower quality heavy oil feedstock is introduced into the enriched fluidized bed reactor instead of the original heavy oil feedstock and an enriched fluidized bed reactor using a dual catalytic system for hydroprocessing of heavy oil lower quality, operates at the same or higher base reactor severity conditions compared to the base reactor severity conditions by: increasing the operating temperature by at least 2.5°C, maintaining and increasing heavy oil throughput, and maintaining and increasing heavy oil conversion relative to the base operating temperature, base heavy oil throughput and base heavy oil conversion, and maintaining or increasing the formation rate converted hydrocarbon products compared to the base rate of formation of converted products, and without increasing the rate of equipment fouling compared to the base rate of equipment fouling when operating a fluidized bed reactor at baseline conditions, enrichment of a fluidized bed reactor to operate the reactor under severe conditions and with the rate of formation converted products, which provides the following of: (i) increased asphaltene conversion, (ii) reduced atmospheric column bottoms (ATB) residue, (iii) increased MCR conversion, (iv) increased API gravity in vacuum column bottoms ( VTB), (v) increased desulfurization, (vi) reduced VTB viscosity, or (v) increased CCR conversion compared to the original fluidized bed reactor operation, where the operation of the enriched fluidized bed reactor at the reactor severity and rate of conversion of converted products causes a fouling rate equipment characterized by at least one of: a frequency of heat exchanger shutdowns for cleaning that is equal to or less than during the original operation of the fluidized bed reactor; frequency of atmospheric and/or vacuum distillation column stops for cleaning, which is equal to -