Process for upgrading a hydrocarbon feedstock with a low pressure hydroprocessing and catalyst rejuvenation / regeneration step

Abstract

Heavy hydrocarbon feedstocks, including crude oil, are upgraded in a ebullated bed hydroprocessing zone under relatively low pressure conditions to remove heteroatom containing hydrocarbons. Catalyst particles are regenerated / rejuvenated and recycled back to the ebullated bed hydroprocessing reaction zone. Regeneration / rejuvenation effectively restores catalytic activity while minimizing leaching of active components.

Description

[0001] Related applications

[0002] not applicable. Background Technology Technical Field

[0003] This invention relates to the use of a low-pressure hydrotreating unit to upgrade hydrocarbon feedstocks, such as crude oil.

[0004] Description of related fields

[0005] Crude oil is conventionally distilled, and subsequently processed through various cracking, solvent refining, and hydroconversion processes to produce a desired range of fuels, lubricants, chemicals, and chemical feedstocks. Examples of conventional processes include distilling crude oil in atmospheric distillation columns to form gas oil, naphtha, gaseous products, and atmospheric residue. Generally, atmospheric residue is further fractionated in vacuum distillation columns to produce vacuum gas oil and vacuum residue.

[0006] Conventionally, hydrotreating is used to remove impurities such as sulfur, nitrogen, and / or metals (especially in residue feedstocks) and to crack heavier hydrocarbons into lighter hydrocarbons to obtain transportation fuels such as gasoline and diesel. Reactions occurring in residue hydrocracking / hydrotreating operations include hydrodesulfurization (HDS), hydronitrogenation (HDN), hydrodemetallization (HDM), carbon reduction (CRR), hydrocracking (HCK), and hydrogenation (HGN).

[0007] Heavy crude oil requires extensive conversion and refining into lighter and cleaner components using expensive technologies that typically employ high pressure and temperature. Integrating these deep conversion and refill technologies into existing refineries can be an expensive addition, and generally, the lower the API value of the crude oil, the more limited the unit will be due to higher levels of associated metals, asphaltenes, sulfur, and nitrogen.

[0008] The market price difference between sweet whole crude oil and sour whole crude oil can be significant. The availability of light, low-sulfur crude oil depends on the production methods and sources. In some geographic areas, oil recovery is limited to heavy crude oil. Furthermore, production based on stage 3 and other enhanced oil recovery technologies primarily yields heavier and sour crude oils.

[0009] Therefore, upgrading crude oil can offer significant advantages to refinery processes. Industrial progress has been made in hydrotreating crude oil and heavy fractions to improve heavy oils before fractionation into separate straight-run distillate fractions. Hydrotreating heavy crude oil for upgrading allows for a reduction in the oil's sulfur content (i.e., "sweetening"), an increase in the API gravity of the heavy oil (i.e., providing lighter crude oil), and a reduction in the metal content of the heavy oil. Heavier crude oils contain a larger proportion of heavy and acidic materials, such as high-boiling vacuum residue fractions. Upgrading heavy crude oil into feedstocks for the efficient production of clean fuels is becoming increasingly important.

[0010] A major technical challenge when hydrotreating heavy oil fractions or full-range crude oil is the impact of low concentrations of contaminants such as organometallic compounds and polynuclear aromatic compounds. Metals often exist in porphyrin-type structures and typically contain nickel and / or vanadium, which have a significant deactivating effect on catalysts. These organometallic compounds, etc., have been shown to reduce the activity or lifetime of hydrotreating catalysts. Metal contaminants and polynuclear aromatic compounds lead to reduced process performance or increased capital and / or operating costs in refinery processing units. Residual metal contaminants from crude oil fractions deposit on the pores of hydrotreating catalysts and cause catalyst deactivation. Polynuclear aromatic compounds are coke precursors and form coke at high temperatures, which also contributes to catalyst deactivation. To minimize catalyst deactivation, hydrotreating units are conventionally designed to operate under high pressure, which inevitably increases both operating costs and capital costs in terms of containers and auxiliary equipment.

[0011] Known processes such as conventional refining can be used to upgrade crude oil, but they are costly due to the demanding hydrotreating designs (including operating pressures above 150 bar). Available methods for upgrading and / or desulfurizing crude oil feedstocks have known limitations. For example, fixed-bed reactor units used to process full-range crude oil require frequent shutdowns to allow catalyst unloading and replacement due to metal contamination. This reduces uptime and, consequently, increases processing costs.

[0012] As the refining industry increasingly processes high-sulfur, low-API crude oil feedstocks, catalyst deactivation has become a significant issue. This is one of the main limiting factors for hydrotreating units. As the heavy hydrocarbon feedstocks being processed become heavier, i.e., with lower API densities, molecular complexity increases. This increase in complexity is both in terms of molecular weight and the degree of unsaturation. Both of these effects increase the feedstock's tendency to coke, a major mechanism contributing to catalyst deactivation. Another factor leading to catalyst deactivation is the metal content present in heavy hydrocarbon feedstocks such as certain crude oil feedstocks. These metals often exist in porphyrin-type structures and typically contain nickel and / or vanadium, which have a significant deactivating effect on catalysts.

[0013] A conventional approach to minimizing catalyst deactivation is to operate the hydrotreatment unit at high pressure levels. However, this leads to complexity in reactor design and construction, as the vessel must operate at these higher pressure levels. Furthermore, capital and operating costs increase with higher pressure levels.

[0014] Therefore, there is a need for improved processes and systems for upgrading crude oil and / or processing heavy residual fractions with high metal content (including organometallic compounds and free metals) and / or high content of polynuclear aromatic compounds. Summary of the Invention

[0015] The aforementioned objectives and further advantages are provided by systems and processes for upgrading heavy hydrocarbon feedstocks, including crude oil. In the hydrotreating subsystem, the feedstock is desulfurized, denitrogenated, and demetallized under relatively low pressure conditions in a fluidized bed hydrotreating zone to remove heteroatoms from hydrocarbons. Heavy hydrocarbon molecules are cracked in the presence of hydrogen to form lighter hydrocarbon molecules to produce upgraded crude oil products (which are, for example, suitable as feedstock for refinery operations tailored for the production of transportation fuels). Catalyst materials effective for residue hydrocracking are utilized in the hydrotreating / hydrocracking steps. Catalyst particles—in some embodiments in the form of alumina, silica, or alumina-silica extrusions—comprising one or more active components for upgrading crude oil or residue (under vacuum or atmospheric pressure) are regenerated / rejuvenated and recycled back to the fluidized bed hydrotreating reaction zone, as described in more detail herein. Regeneration / rejuvenation effectively restores catalytic activity while minimizing the leaching of active components.

[0016] In one embodiment, the process for upgrading crude oil includes hydrotreating a heavy hydrocarbon feedstock at a hydrogen partial pressure of less than 100 bar in a fluidized bed hydrotreating unit with associated fluidized bed pumps and a catalyst replacement system to produce an effluent, which is collected as upgraded heavy hydrocarbon effluent. The catalyst used in the fluidized bed hydrotreating unit comprises heterogeneous catalyst particles having an active component introduced onto a support, and is characterized by its initial catalytic activity when the catalyst particles are freshly added to the fluidized bed hydrotreating unit. Depleted catalyst particles containing contaminant metals and coke are removed from the fluidized bed hydrotreating unit. Compared to the initial catalytic activity, the depleted catalyst particles exhibit reduced catalytic activity. The next step is to regenerate the depleted catalyst particles to reduce contaminant metals and produce intermediate regenerated catalyst particles. The intermediate regenerated catalyst particles are then regenerated to reduce coke and produce regenerated / reconstituted catalyst particles. The regenerated / reconstituted catalyst particles have increased catalytic activity relative to the depleted catalyst particles and are recycled back to the fluidized bed hydrotreating unit.

[0017] In the above process, the heavy hydrocarbon feedstock may include crude oil, crude oil with naphtha removed, atmospheric residue, or vacuum residue.

[0018] In the above process, the upgraded heavy hydrocarbon effluent can be separated into light fractions and upgraded heavy fractions. The upgraded heavy fraction may include atmospheric residue or vacuum residue. All or part of the upgraded heavy fraction can be recycled to the fluidized bed hydrotreating unit. The light fraction can be hydrotreated in a fixed bed hydrotreating unit to produce a hydrotreated light fraction effluent. The hydrotreated light fraction effluent can be combined with the upgraded heavy fraction to produce a further upgraded heavy hydrocarbon effluent.

[0019] In one embodiment, the process for upgrading a crude oil feed stream includes fractionating crude oil into distillate fractions and atmospheric residue, hydrotreating the distillate fractions in a fixed-bed hydrotreating unit to produce a hydrotreated distillate effluent, and hydrotreating the atmospheric residue in a fluidized-bed hydrotreating unit with an associated fluidized-bed pump and catalyst replacement system at a hydrogen partial pressure of less than 100 bar to produce an effluent, which is collected as the upgraded residue effluent. The catalyst used in the fluidized-bed hydrotreating unit comprises heterogeneous catalyst particles having an active component incorporated on a support, and is characterized by initial catalytic activity when the catalyst particles are freshly added to the fluidized-bed hydrotreating unit. Depleted catalyst particles containing contaminant metals and coke are removed from the fluidized-bed hydrotreating unit. Compared to the initial catalytic activity, the depleted catalyst particles have reduced catalytic activity. The next step is to regenerate the depleted catalyst particles to reduce contaminant metals and produce intermediate regenerated catalyst particles. The intermediately regenerated catalyst particles are then regenerated to reduce coke and produce regenerated / reclaimed catalyst particles. These regenerated / reclaimed catalyst particles have increased catalytic activity relative to the depleted catalyst particles and are recycled to the fluidized bed hydrotreating unit. In some embodiments, the hydrotreated distillate effluent can be combined with upgraded residue to produce upgraded crude oil.

[0020] In any of the above processes, the catalytic activity of the regenerated / reclaimed catalyst particles is 95%, 96%, 97%, 98%, 99%, or 99.9% of the initial catalytic activity. In the above processes, metals accumulate on the catalyst particles during the reaction in the fluidized bed hydrotreating unit, and up to 70, 75, 80, 90, 95, or 99% by weight of the metal accumulated on the catalyst particles is removed. Regeneration of spent catalyst particles generally involves solvent washing and acid washing to remove unwanted metals. Regeneration of intermediately regenerated catalyst particles generally involves combustion in an oxidizing atmosphere to burn off carbonaceous species and redisperse the active phase metals on the catalyst particles.

[0021] A system for upgrading crude oil includes a fluidized bed hydrotreating unit, comprising an associated fluidized bed pump and a catalyst replacement system. The fluidized bed hydrotreating unit includes one or more inlets in fluid communication with a source of heavy hydrocarbon feedstock and hydrogen, one or more inlets in fluid, slurry, or solid communication with a source of regenerated / reclaimed catalyst particles, one or more outlets for discharging vapor / liquid products, and one or more outlets for discharging spent catalyst particles. The catalyst used in the fluidized bed hydrotreating unit comprises heterogeneous catalyst particles having an active component introduced onto a support, and is characterized by its initial catalytic activity when the catalyst particles are freshly added to the fluidized bed hydrotreating unit, wherein spent catalyst particles from the fluidized bed hydrotreating unit contain contaminant metals and coke, and have reduced catalytic activity compared to the initial catalytic activity. The regeneration system is configured to communicate with the one or more outlet fluid, slurry, or solid communication for discharging spent catalyst particles and is operable to produce intermediate regenerated catalyst particles. The regeneration system is configured to be in fluid, slurry, or solid communication with the regeneration system to receive intermediate regenerated catalyst particles and is operable to produce regenerated / reconstituted catalyst particles. The regeneration system is the source of regenerated / reconstituted catalyst particles, which have increased catalytic activity relative to depleted catalyst particles.

[0022] Other aspects, embodiments, and advantages of the process of the present invention are discussed in detail below. Furthermore, it should be understood that the foregoing information and the following detailed description are merely illustrative examples of various aspects and embodiments, and are intended to provide an overview or framework for understanding the nature and characteristics of the claimed features and embodiments. The accompanying drawings are illustrative and are provided for further understanding of the various aspects and embodiments of the process of the present invention. Attached Figure Description

[0023] The invention will now be described in further detail and with reference to the accompanying drawings (in which like or similar elements are designated by the same reference numerals), and wherein:

[0024] Figure 1 It is a schematic process flow diagram of one embodiment of a process for producing upgraded crude oil, including a low-pressure hydrotreating processor integrated with a catalyst regeneration system.

[0025] Figure 2 This is a schematic process flow diagram of another embodiment of a process for producing upgraded crude oil, which includes a fractionator, followed by a hydrotreating unit for distillate processing, and a low-pressure hydrotreating unit integrated with a catalyst regeneration system for processing the bottom product (tower bottom); and

[0026] Figure 3 This is a schematic diagram of a fluidized bed hydrogenation processor. Detailed Implementation

[0027] A process configuration has been disclosed that enables the upgrading of heavy hydrocarbon feedstocks using low-pressure fluidized bed hydrotreating integrated with online catalyst regeneration / regeneration. Thus, heavy hydrocarbon feedstocks such as crude oil are upgraded and / or desulfurized.

[0028] As used herein, the term "stream" (and variations thereof, such as hydrocarbon stream, feed stream, product stream, etc.) may include one or more of the following: various hydrocarbon compounds, such as straight-chain, branched or cyclic alkanes, alkenes, dienes, alkynes, alkyl aromatics, alkenyl aromatics, fused and unfused di-, tri- and tetra-aromatics, and gases such as hydrogen and methane, C2+ hydrocarbons, and may further include various impurities.

[0029] The term "zone" refers to an area that includes one or more devices or one or more sub-zones. Devices may include one or more reactors or reactor vessels, heaters, heat exchangers, piping, pumps, compressors, and controllers. Additionally, devices such as reactors, dryers, or vessels may be further included in one or more zones.

[0030] Volume percentage, or "V%", refers to a relative value under conditions of 1 atmosphere and 15°C.

[0031] The phrase “a major portion” in relation to a particular flow or a plurality of flows means at least about 50% by weight and up to 100% by weight, or the same value in another specified unit.

[0032] The phrase “a significant portion” for a particular flow or a plurality of flows means at least about 75% by weight and up to 100% by weight, or the same value in another specified unit.

[0033] The phrase “a substantial portion” for a particular flow or a plurality of flows means at least about 90, 95, 98 or 99 percent by weight and up to 100 percent by weight, or the same value in another specified unit.

[0034] The phrase “a minor portion” for a particular flow or a plurality of flows means about 1, 2, 4 or 10% by weight, up to about 20, 30, 40 or 50% by weight, or the same value in another specified unit.

[0035] As used herein, the term "crude oil" refers to petroleum extracted from geological formations in its unrefined form. Suitable crude oils as source materials for the processes described herein include Arab Heavy crude, Arab Light crude, Arab Extra Light crude, other Gulf crude, Brent crude, North Sea crude, North and West African crude, Indonesian crude, Chinese crude, North or South American crude, Russian and Central Asian crude, or mixtures thereof. Crude oil mixtures may be a full range of crudes or top-loaded crudes. As used herein, "crude oil" also refers to such mixtures that have undergone some pretreatment, such as water-oil separation; and / or gas-oil separation; and / or desalting; and / or stabilization. In some embodiments, crude oil refers to any such mixture having an API specific gravity (ASTM D287 standard) greater than or equal to about 20°, 30°, 32°, 34°, 36°, 38°, 40°, 42°, or 44°.

[0036] Heavy hydrocarbon feedstocks undergoing the processes described herein include residue oil, short residue oil, long residue oil, or other heavy fractions (including those with a nominal boiling range above the naphtha boiling range, for example, above about 170-200°C; with a nominal boiling range above the atmospheric gas oil boiling range, for example, above about 330-370°C; or with a nominal boiling range above the vacuum gas oil boiling range, for example, above about 370-400°C). Heavy hydrocarbon feedstocks may be derived from naturally occurring hydrocarbons, including crude oil, synthetic crude oil, bitumen, oil sands, shale oil, coal liquefaction, or combinations thereof. In some embodiments, heavy hydrocarbon feedstocks undergoing the processes described herein may be vacuum gas oil, deasphalted oil and / or demetallized oil obtained from solvent deasphalting processes, light or heavy coking gas oil obtained from coking processes, cycle oil obtained from FCC processes, gas oil obtained from viscous cracking processes, coal liquefaction, any combination of oil products derived from biomaterial conversions such as cellulose, wood pyrolysis, or the aforementioned partially refined products. In some embodiments, the heavy hydrocarbon feedstock is obtained as atmospheric or vacuum residue from a crude oil distillation column, such as an atmospheric or vacuum distillation column. In other embodiments, the heavy hydrocarbon feedstock may be full-range crude oil, topped crude oil, and crude oil or topped crude oil that has undergone some pretreatment (e.g., water-oil separation, gas-oil separation, desalting, and / or stabilization). In some embodiments, the heavy hydrocarbon feedstock is crude oil having a mixture of hydrocarbon compounds having a boiling point in the range of about 36°C to a endpoint, such as about 1500°C. In further embodiments, the heavy hydrocarbon feedstock includes atmospheric and / or vacuum residue fractions having an endpoint value corresponding to the heaviest component of the feedstock, such as equal to or higher than about 1500°C, and a boiling point value in a lower range starting at 370-520°C, 370-450°C, or 450-520°C. Such fractions include one or more streams in the range of vacuum residue (e.g., boiling point above about 520°C) or atmospheric residue (e.g., boiling point above about 370°C). In another embodiment, the heavy hydrocarbon feedstock may include hydrocarbons in the range of vacuum or atmospheric residue, combined with lighter components such as vacuum gas oil typically boiling in the range of about 370-520°C or atmospheric gas oil typically boiling in the range of about 240-370°C.

[0037] Heavy hydrocarbon feedstocks, including crude oil, are upgraded in a fluidized bed hydrotreating zone under relatively low pressure conditions to remove heteroatoms. The catalyst particles are then regenerated / recycled back into the fluidized bed hydrotreating reaction zone. This regeneration / regeneration effectively restores catalytic activity while minimizing the leaching of active components.

[0038] In the process and system described herein, the fluidized bed hydrotreating zone operates at a low pressure level compared to known hydrotreating operations for processing heavy hydrocarbon feedstocks, in order to remove metals (including those present in the initial feedstock in porphyrin form), reduce nitrogen and sulfur content, increase API gravity, reduce microcarbon residue (MCR), and reduce asphaltenes. This process utilizes a low-pressure fluidized bed hydrotreating zone integrated with a catalyst regeneration / reconstitution system to upgrade heavy hydrocarbon feedstocks. The catalyst particles—in some embodiments in the form of alumina, silica, or alumina-silica extrusions, including one or more active components for upgrading crude oil or residue (reduced or atmospheric pressure)—are regenerated / reformed and recycled back to the fluidized bed hydrotreating reaction zone, as described in more detail herein. Regeneration / reconstitution effectively restores catalytic activity while minimizing the leaching of active components.

[0039] Typically, operations involving crude oil require high pressures, such as greater than about 150, 160, 170, or 180 bar, or greater than about 120 bar for residue. In the process and system described herein, the fluidized bed hydrotreating zone operates at relatively low hydrogen partial pressure levels (e.g., less than about 120, 110, 100, 95, 90, 80, or 70 bar). As a result, significant capital cost savings can be achieved during reactor design and construction. Typical fluidized bed hydrotreating reactors for processing crude oil or residue require wall thicknesses of at least about 18, 19, 20, 21, 22, or 24 cm, which can weigh, for example, about 315, 335, 354, 369, 383, or 411 metric tons for a 100,000 barrels / day unit. In contrast, this process can use reactors with wall thicknesses of approximately 15, 14, 13, 12, 10, or 9 cm, which can weigh, for example, approximately 275, 256, 236, 216, 197, or 177 metric tons for a 100,000 barrels / day unit. For example, if the operating pressure is reduced from 150 bar to 70 bar for a 100,000 barrels / day unit, the cost savings in capital investment can be approximately 40%. Furthermore, operating costs are reduced with the decrease in hydrogen consumption, as a large amount of hydrogenation reaction occurs at higher pressures.

[0040] When operating at lower pressures, catalyst particles in the fluidized bed hydrotreating reaction zone deactivate rapidly, leading to high catalyst consumption rates. Other drawbacks of conventional low-pressure units include operational problems caused by coke buildup, deposits, etc. Therefore, low-pressure operation is generally not considered a practical solution for upgrading heavy hydrocarbon feed streams (including crude oil). However, this process overcomes these limitations by integrating a catalyst regeneration / reconstitution system, enabling the upgrading of crude oil or its heavy fractions to obtain low-sulfur light crude oil or synthetic crude oil. In the integrated process and system described herein, catalyst particles (catalyst extrudate in some embodiments) are regenerated / reconstituted and recycled back to the fluidized bed hydrotreating reaction zone.

[0041] In embodiments where the heavy hydrocarbon feedstock is crude oil, the resulting product can be treated crude oil, referred to as synthetic crude oil or upgraded crude oil. In embodiments where the heavy hydrocarbon feedstock is residual fractions such as vacuum or atmospheric residue, the resulting product can be treated residue (vacuum or atmospheric), referred to as upgraded residue (vacuum or atmospheric).

[0042] In some embodiments of the process of this invention, crude oil or residual fractions are upgraded by hydrotreating (including HDM, HDN, HDS, CRR, HCK, and / or HGN and combinations thereof) to produce treated crude oil or treated residue. In some embodiments, the upgraded synthetic crude oil product contains 50 ppmw or less of sulfur and has an API gravity value increased by at least 10 degrees compared to the initial crude oil feedstock.

[0043] Under the low-pressure conditions used in the fluidized bed hydrotreating operation described in this paper, the catalyst will deactivate faster than in similar systems operating at higher pressures because coke will more readily form on the catalyst material at lower pressures. A significant or substantial portion of the heavy hydrocarbon feedstock used in the process described in this paper is in the form of metalloporphyrins. The metal in the porphyrin structure deposits as a metal on the surface of the catalyst particles, thus preventing access to active sites, and the organometallic diffuses into the pores of the catalyst particles. As the hydrogen partial pressure increases, the hydrogenation reaction increases, and more metal is deposited on the surface of the catalyst particles. Under lower hydrogen partial pressures, some coke precursors (metal-containing asphaltenes) polymerize and deposit as coke on the catalyst, where the metal is within the coke structure. As a result, the adverse effects of rapid catalyst deactivation in the process and system described in this paper necessitate a relatively high catalyst replacement rate, which is achieved through an integrated catalyst regeneration / regeneration zone. The hydrogen partial pressure in the fluidized bed hydrotreating reactor in the integrated process described in this article is typically 30-100, 40-100, 60-100, 30-90, 40-90, 40-80, 60-100, 60-90, or 60-80 bar, while conventional fluidized bed processes for processing crude oil or residue operate at pressure levels greater than approximately 150-200 (for crude oil) or 120-200 (for residue).

[0044] Catalyst regeneration / regeneration is carried out in the integrated fluidized bed hydrotreating system and process described herein to restore catalytic activity while minimizing the leaching of active components. This catalyst regeneration / regeneration process includes a regeneration sub-process for removing the target metal and a regeneration sub-process for removing accumulated coke. The process and system can be optimized by utilizing catalyst deactivation profiles and catalyst regeneration characteristics. The catalytic activity of the regenerated / regenerated degraded catalyst particles can be restored to 95, 96, 97, 98, 99, or 99.9% of the original activity of the corresponding fresh catalyst particles according to the processes described herein. In some embodiments, up to 70, 75, 80, 90, 95, or 99% by weight of metals accumulated on the catalyst particles are removed according to the regeneration / regeneration performed herein.

[0045] In the catalyst regeneration / regeneration process integrated in this paper, a regeneration step is performed first, and coke accumulates on the surface of the catalyst particles during the reaction to protect the active phase metal from leaching. If the opposite occurs, with regeneration taking place on the regenerated particles, the likelihood of catalyst damage increases due to the leaching of both the active phase metal and the support material.

[0046] Catalyst regeneration occurs on catalyst particles from a fluidized bed hydrotreating unit and typically includes solvent washing and acid washing to remove unwanted metals, and in some embodiments includes water washing. The intermediate regenerated catalyst is provided and then subjected to regeneration to remove coke and produce regenerated / reclaimed catalyst particles.

[0047] Acid leaching removes target contaminant metals such as nickel and vanadium compounds from spent catalysts, with minimal removal of the catalyst's active metals and support material. Spent catalysts leached by acid typically undergo water washing to remove residual acid solution. For example, solvent washing can be carried out at a solvent:catalyst weight ratio in the range of approximately 1:1 to 3:1, at a catalyst temperature of approximately 35–80 °C, for a contact time of approximately 60–120 minutes, and with stirring at a speed in the range of approximately 1–20 rpm; acid washing can be carried out at an acid:catalyst weight ratio in the range of approximately 1:1 to 3:1, for a contact time of approximately 60–120 minutes, and with stirring at a speed of approximately 1–20 rpm. Water washing can be carried out within similar time ranges and with similar stirring speeds as solvent and acid washing.

[0048] Suitable catalyst regeneration systems are disclosed in U.S. Patents 5,925,238 and 5,906,953 to Duddy et al., both of which are incorporated herein by reference in their entirety. The catalyst regeneration system comprises a vessel having inlet and outlet openings for the catalyst and a washing liquid, and is arranged to facilitate successive solvent liquid washing, water washing, and acid treatment steps. The solvent liquid washing uses a polar organic solvent that is both oil-soluble and water-soluble, such as acetone or other similar organic solvent liquids, followed by water washing of the substantially oil-free catalyst to remove the solvent, without the need for any gas drying step. Further process steps include treating the oil-free catalyst with a suitable dilute acid solution such as 1-30, 5-30, 10-30, 1-20, 5-20, or 10-20% sulfuric acid or other acids such as acetic acid, hydrochloric acid, and nitric acid. The acid treatment is used to substantially remove contaminant metals such as nickel and vanadium compounds from the used catalyst, and only minimally removes the catalyst's active metal and support material, followed by a second water washing of the acid-treated catalyst to remove residual acid solution. The acid treatment solution, temperature, and duration are selected such that the removal of active metals from the catalyst does not exceed about 0.1, 1, 2, 4, or 6% by weight. Since the polar solvents and acid liquids used in the washing and treatment steps are soluble in both oil and water, the catalyst regeneration process can utilize a two-step water washing procedure for solvent-washed and acid-treated catalysts (the solvents and acid liquids can then be recovered by distillation for reuse in the regeneration process). The catalyst regeneration system also includes suitable unit operations to heat and oxidize the solvent-washed and acid-treated catalyst at appropriate high temperatures and durations during contact with an oxygen-containing gas, such as an inert gas / air or a steam / air mixture, to burn off and remove substantially all coke deposits from the catalyst.

[0049] Other suitable catalyst regeneration systems include those disclosed in Ganguli's U.S. Patents 4,454,240 and 4,595,666, both of which are incorporated herein by reference in their entirety. In these processes, spent catalyst material is regenerated through solvent washing and acid treatment steps, wherein the spent catalyst is washed, for example, with naphtha or toluene solvents to remove retained heavy oils. The washed catalyst material is heated to remove retained solvents, and then washed with water to fill the catalyst pores. The water-washed catalyst material is then transferred to an acid treatment vessel and contacted with a dilute acid solution. The acid-treated catalyst is washed with water to remove retained acid, and then the material is dried and oxidized at a desired high temperature to burn off carbon deposits.

[0050] Other suitable catalyst regeneration systems include those disclosed in U.S. Patents 4,769,219 and 4,863,884 to Tasker et al., both of which are incorporated herein by reference in their entirety. In these processes, the used catalyst is regenerated in a single vessel using successive steps of solvent washing, vacuum drying, acid treatment, and gas drying.

[0051] Following catalyst regeneration as described above, the regenerated, degraded catalyst particles still include accumulated coke on their surfaces. Coke is a term used for large carbonaceous species that typically contain polyaromatic rings. These species completely or partially cover the active sites on the catalyst particles. These carbonaceous species also block the pores of the catalyst particles.

[0052] The accumulated coke is partially or completely removed by catalyst regeneration, a combustion process used to restore the activity of catalyst particles through the combustion of coke. Depending on the degree of coke accumulation and / or regeneration conditions, the restoration of catalyst particles can be substantially complete. For example, using an oxidizing atmosphere, typically air or an oxygen-enriched gas, at temperatures in the range of about 400-900, 450-800, or 480-600°C, the catalyst regeneration process removes coke from the catalyst by burning carbonaceous species, redispersing the active phase metal on the catalyst and removing other residual contaminants. In a typical regeneration process, a complete combustion process is carried out, producing CO2 as a byproduct, in contrast to gasification, which is a partial combustion process that produces syngas (H2 + CO). By using an oxidizing atmosphere, the catalyst regeneration process removes coke from the catalyst by burning carbonaceous species. This redisperses the active phase metal on the catalyst particles and also removes other residual contaminants. In some embodiments, regeneration converts the sulfide phase back to an oxide phase similar to the oxide phase of the fresh catalyst.

[0053] The fluidized bed hydrotreating subsystem can be configured as a single pass (single reactor); a series flow configuration with two or more reactors; or a series flow configuration having two or more reactors with a separation step between the reactors, the reactors containing one or more catalysts designed for HDM, HDS, HDN, CRR, HCK and HGN.

[0054] The reactor configuration for hydrotreating according to the processes and systems described herein includes a fluidized bed hydrotreating unit, which is particularly effective for continuous, periodic, or on-demand catalyst replacement. The fluidized bed hydrotreating unit may include one or more reactors known in the art and associated fluidized bed pumps and gas / liquid separators.

[0055] In some embodiments, multiple reactors are arranged in series, for example, each reactor performing a different catalytic function, including HDM, HDN, HDS, CRR, HCK, and / or HGN, and combinations thereof. In some embodiments, a series arrangement of vessels is used, wherein the catalyst in each vessel is different and is individually regenerated / regenerated, and the conversion rate can be increased due to optimized catalyst. In other embodiments, a series arrangement of vessels is used, wherein the catalyst in each vessel is different, and wherein catalyst particles from one or more of the vessels are conventionally treated or regenerated, and wherein catalyst particles from one or more of the vessels are regenerated / regenerated as described herein. For example, HDM catalyst particles may be used in the first vessel and conventionally treated or regenerated because they are the most contaminated, and less contaminated catalyst particles from subsequent hydrotreating steps (HDS, HDN, CRR, HCK, and / or HGN) may undergo regeneration / regeneration as disclosed herein. In a further embodiment, HDM catalyst particles may undergo regeneration / regeneration as disclosed herein.

[0056] In some embodiments, multiple reactors are arranged in series, for example, each reactor performing the same catalytic function, including HDM, HDN, HDS, CRR, HCK, and / or HGN and combinations thereof. In some embodiments, a series arrangement of containers is used, with a gas / liquid separator between them, wherein the catalyst in each container is identical and is regenerated / regenerated in a common unit, and the conversion rate can be increased by increasing the liquid hourly or heavy hourly space velocity.

[0057] In some embodiments, multiple reactors are arranged in parallel, for example, each reactor performing the same catalytic function, including HDM, HDN, HDS, CRR, HCK, and / or HGN and combinations thereof. In some embodiments, a parallel arrangement of vessels is used, wherein the catalyst in each vessel is identical and is regenerated / regenerated in a common subsystem, and the conversion rate can be increased by increasing the liquid hourly or heavy hourly space velocity.

[0058] In the hydrotreating operation described in this paper, combined with the aforementioned low-pressure conditions, the following general operating conditions can be adopted: a temperature in the range of approximately 350-500°C, and a reactor volume of approximately 0.1-2.0 or 0.1-4.0 h. -1 Liquid hourly space velocity (LHSV) within the range, hydrogen-to-oil ratio of 500-2500 or 700-2500 standard liters of hydrogen / liter of oil, and catalyst replacement rate between approximately 0.1-5 or 0.1-10 kg catalyst / m³ of feed.

[0059] Figure 1This is a schematic process flow diagram of a method and system for upgrading heavy hydrocarbon feedstocks, comprising fluidized bed hydrotreating and catalyst regeneration / regeneration. Heavy hydrocarbon feedstock 102 is introduced into a low-pressure fluidized bed hydrotreating reaction zone 120 along with hydrogen 104 and catalyst particulate feed 106. Catalyst particulate feed 106 can be used to introduce catalyst particles at start-up and / or to introduce additional supplementary catalyst particles as needed during the reaction. The fluidized bed hydrotreating reaction zone 120 is operated under conditions of effective removal of heteroatoms, hydrocracking of heavy molecules, and / or hydrogenation of hydrocarbons to produce upgraded heavy hydrocarbon effluent 124, as described herein. In some embodiments, upgraded heavy hydrocarbon effluent 124 is upgraded crude oil or upgraded residue. As known in the operation of fluidized bed reactors, a certain amount of catalyst particulate material is removed from the hydrotreating unit 120, schematically represented by feed 122. In some embodiments, this catalyst removal and corresponding catalyst addition can be performed at predetermined time intervals, e.g., every 0.5-8 days. In some embodiments, the catalyst removal and corresponding catalyst addition can be continuous or semi-continuous. The feed-to-catalyst ratio can be, for example, 0.1-10.0 barrels of heavy hydrocarbon feedstock / kg catalyst. Catalysts that are completely or partially degraded due to metal and coke deposition are transferred to the catalyst regeneration / regeneration system 130. By removing metals from the catalyst particles in the regeneration step and removing coke from the catalyst surface in the regeneration step, the catalytic activity is almost restored to that of fresh catalyst material.

[0060] All, most, a significant portion, or a large portion of the regenerated / reclaimed catalyst is recycled back to the fluidized bed hydrotreating zone 120 via feed stream 132. Due to its low-pressure design, the fluidized bed hydrotreating unit consumes more catalyst compared to the conventional high-pressure design of fluidized bed hydrotreating units used for crude oil or residue processing; however, the high catalyst consumption, which leads to high catalyst costs, is offset by catalyst recycling. Due to wear, a certain proportion of catalyst material or powder is removed from the system via feed stream 134. In some operations, additional fresh catalyst particles are added during operation via feed stream 106. Catalyst addition requirements can be determined, for example, during pilot and unit design phases, and are related to catalyst activity based on the given properties and characteristics of the feedstock. Furthermore, catalyst can be added to compensate for catalyst removed due to lifespan limitations. In some embodiments, contaminant composition, physical properties, and mechanical properties are monitored to determine the amount removed.

[0061] In some optional embodiments, the upgraded heavy hydrocarbon effluent 124 can be further upgraded by integrating one or more downstream high-pressure separators and one or more fixed-bed hydrotreating units (shown as units 150 and / or 160, indicated by dashed lines). The effluent 124 from the hydrotreating unit 120 can be separated in a separator 140 into a bottom stream 142 containing hydrocarbons with a nominal boiling range in the atmospheric and / or vacuum residue range, and a light stream 144 containing atmospheric and / or vacuum distillates and gas streams, H2S, NH3, C1-C4, and hydrogen. In some embodiments, all or a portion of the bottom stream 142 (shown as stream 144) can be recycled back to the fluidized bed hydrotreating unit 120. In some embodiments, all or a portion of the bottom stream 142 (shown as stream 146) may be treated in a unit such as a residue hydrotreating unit 160 (which may be a fixed-bed or separate fluidized-bed reactor) to produce a further upgraded residue stream 162 (which may optionally be combined with the product from unit 150 as a combined upgraded effluent 154). In some embodiments, all or a portion of the bottom stream 142 may be combined with the product from unit 150 as a combined upgraded effluent 154 (i.e., bypassing or not utilizing the residue hydrotreating zone 160). Stream 144 may be hydrotreated in one or more integrated fixed-bed hydrotreating units 150 for further upgrading, for example, which may include separate units for distillates and vacuum gas oil. In some embodiments, the hydrotreated distillate effluent 152 (from which light gases including H2S, NH3, C1-C4 and hydrogen (not shown) have been removed) can be combined with the bottom stream 142 from the high-pressure separator 140 to produce a further upgraded heavy hydrocarbon effluent 154, such as upgraded synthetic crude oil when the initial feedstock is crude oil. In other embodiments, these streams can be collected separately.

[0062] refer to Figure 2This illustrates another embodiment of a process for producing upgraded crude oil. Hydrocarbon feedstock 202 is fractionated in an atmospheric fractionation tower 210 to separate the crude oil into: a distillate fraction 214, which, for example, contains hydrocarbons with a full-range naphtha and distillate (e.g., a nominal starting boiling point of about 36°C to a nominal ending point in the range of about 330-370°C), or heavy naphtha and distillate (e.g., a nominal starting boiling point in the range of about 70-90°C to a nominal ending point in the range of about 330-370°C); and an atmospheric residue fraction 212, which, for example, contains hydrocarbons with a nominal boiling range of about 330-400°C or higher. The distillate fraction 214 and hydrogen 216 are introduced into a fixed-bed hydrotreating unit 270 for hydrotreating to produce a treated effluent 274. Atmospheric residue fraction 212 is introduced along with hydrogen 204 and catalyst 206 into a low-pressure hydrotreating processor 220, which operates under conditions that effectively remove heteroatoms, hydrogenate and hydrocracking heavy molecules, and produce upgraded residue 224. In some embodiments, all or a portion of the treated effluent 274 is combined with all or a portion of the upgraded residue 224 to form an upgraded feedstock 280, such as upgraded synthetic crude oil when the initial feedstock is crude oil. In some embodiments, a portion of the distillate from feedstock 224 may be separated and sent to a fixed-bed hydrotreating processor for further processing.

[0063] A portion of the catalyst material is removed from the hydrogenation processor 220 at predetermined time intervals, schematically shown via feed stream 222. Catalysts that are completely or partially degraded due to metal and coke deposition are transferred to the catalyst regeneration system 230. The catalytic activity of the catalyst material is restored by removing metals and coke from the catalyst surface in the catalyst regeneration system. The regenerated catalyst is recycled back to the hydrogenation processor via feed stream 232. A certain proportion of the catalyst material is removed from the system via feed stream 234.

[0064] The fluidized bed hydrotreating unit operation in the systems and methods described herein includes a catalyst replacement subsystem. Fluidized bed reactors are generally used in hydrotreating to overcome clogging problems typically associated with fixed bed reactors (e.g., during the processing of relatively heavy feedstocks). Fluidized bed reactors are incorporated into various refinery operations, including processes for upgrading heavy liquid hydrocarbons and converting coal into synthetic oils. In a fluidized bed reactor, the catalyst is located in an expanded bed, thus avoiding the clogging problems associated with fixed bed reactors. The fluidizing properties of the catalyst in a fluidized bed reactor also allow for online replacement of small portions of the catalyst in the bed on a continuous or intermittent basis. This results in a high net bed activity that does not change over time. Known fluidized bed processes and systems are described by Johanson in U.S. Patents 2,987,465 and 3,197,288, both of which are incorporated herein by reference.

[0065] refer to Figure 3A fluidized bed reactor 320a generally comprises a liquid feed stream, or a slurry of liquid and solids, flowing in parallel through a vertically oriented cylindrical container containing a catalyst, and a gas. The catalyst is placed in the liquid and moves, having a total volume dispersed in the liquid medium that is greater than the volume of the substance at rest. Typically, a liquid hydrocarbon phase and a gaseous hydrogen phase are passed upward through the catalyst particle bed at a certain rate, such that the particles are forced to move as the fluid passes upward through the bed. The feed stream and the hydrogen stream are introduced near the bottom of the vessel via inlet 321. The catalyst bed may be held, for example, by a distributor grid 322, characterized by a settled catalyst level 323 and an expanded catalyst level 324. The expanded catalyst level is determined at least in part by the bottom recirculated liquid flow rate, which is controlled by a fluidized bed pump. During steady-state operation (fluidized bed state), most of the catalyst does not rise above a certain expanded catalyst level 324 in the reactor (in some embodiments, a level predetermined during reactor design). A significant portion of the product vapor and liquid enters the substantially catalyst-free zone 325 through the upper level of the catalyst particles and is removed via a conduit 326 near the top of the reactor. Gas 328 and a portion of the liquid effluent 329 are collected via a gas / liquid separator 327. Other liquids, such as heavier liquids, are transferred, for example, via a recycle cup 330 to the catalyst-free zone 331 at the bottom of the reactor and removed from this zone as net product effluent 332 and recycle stream 333. A portion of the vapor is separated from the liquid recycle stream before being drawn through a recycle conduit pumped by a boiling pump 334. Catalyst material is added 335 and removed 336 on a continuous or intermittent basis.

[0066] Effective catalysts used in fluidized bed hydrotreating zones include heterogeneous catalyst particles with HDM, HDN, HDS, CRR, HCK, and / or HGN functions. The catalyst typically contains one or more active components for upgrading crude oil or residue (under vacuum or atmospheric pressure). The active components are typically metals or metal compounds (oxides or sulfides) selected from Groups 6, 7, 8, 9, and 10 of the IUPAC periodic table. One or more active metal components are typically deposited or otherwise introduced onto a support, which can be amorphous and / or structured, such as alumina, silica-alumina, silica, titanium dioxide, titanium dioxide-silica, or titanium dioxide-silicate. Combinations of active metal components can consist of different particles containing a single active metal species or particles containing multiple active species. For example, effective hydrotreating catalysts include one or more active metal components selected from Co, Ni, W, and Mo (oxides or sulfides), which are typically introduced onto an alumina support along with other additives. The active metal component is introduced at an effective concentration, for example, in the range of 1-40, 1-30, 1-10, 1-5, 2-40, 2-30, 2-10, 3-40, 3-30, or 3-10 (based on the mass of the oxide, sulfide, or metal, as a percentage by weight relative to the total mass of the catalyst). In some embodiments, the active metal component includes one or more of Co, Ni, W, and Mo, and the effective concentration is based on the total mass of the oxide-based active metal component. In some embodiments, the hydrotreating catalyst includes Ni / W / Mo, Co / Mo, Ni / Mo, Ni / W, and / or Co / Ni / Mo. Combinations of one or more types of Ni / W / Mo, Co / Mo, Ni / Mo, Ni / W, and / or Co / Ni / Mo catalysts may be used in some embodiments.

[0067] Catalyst particles are provided in suitable sizes and shapes, such as granules, extrusions, tablets, or pellets, and can be formed into various shapes or forms, such as spherical, cylindrical, trilobal, tetralobal, or naturally occurring shapes. In some embodiments, the catalyst particles have a pore volume in the range of about (cc / gm) 0.15-1.70, 0.15-1.50, 0.30-1.50, or 0.30-1.70; in about (m 2 Specific surface area in the range of 100-400, 100-350, 100-300, 150-400, 150-350, 150-300, 200-400, 200-350 or 200-300; and average pore size of at least about 10, 50, 100, 200, 500 or 1000 angstrom units.

[0068] Example

[0069] 1000 kg of Arab heavy crude oil (its properties are shown in Table 1) was processed according to... Figure 1 The configuration shown involves hydrogenation. The catalyst used is a commercially available alumina-based fluidized bed catalyst. The catalyst contains nickel and molybdenum as active phase metals. Low-sulfur, light synthetic crude oil is produced. Within 0.5 hours... -1 The fluidized bed reactor was operated at an LHSV of 370 °C and a hydrogen partial pressure of 80 bar. The material balance is given in Table 1.

[0070] Table 1 - Material Balance

[0071]

[0072]

[0073] The process and system of the present invention have been described above and in the accompanying drawings; however, modifications will be apparent to those skilled in the art, and the scope of protection of the present invention will be defined by the appended claims.

Claims

1. A process for processing naphtha-removed crude oil, said naphtha-removed crude oil being a mixture of hydrocarbon compounds having an initial boiling point of 170-200°C and a final boiling point corresponding to the heaviest component of said crude oil, said process comprising: The crude oil, after naphtha removal, is hydrotreated in a fluidized bed hydrotreating unit with an associated fluidized bed pump and catalyst replacement system at a hydrogen partial pressure of 30-90 bar to produce an effluent, which is collected as an upgraded heavy hydrocarbon effluent. The upgraded heavy hydrocarbon effluent is separated into light fraction and upgraded heavy fraction. The light fraction is hydrogenated in a fixed-bed hydrotreating processor to produce a hydrotreated light fraction effluent; and The hydrogenated light distillate effluent is combined with the upgraded heavy distillate to produce a further upgraded heavy hydrocarbon effluent. The catalyst particles used in the fluidized bed hydrotreating unit include heterogeneous catalyst particles having an active component introduced onto a support, and are characterized by their initial catalytic activity when the catalyst particles are freshly added to the fluidized bed hydrotreating unit. Degraded catalyst particles containing contaminant metals and coke are removed from the fluidized bed hydrotreating unit, wherein the degraded catalyst particles have reduced catalytic activity compared to the initial catalytic activity; Regeneration of spent catalyst particles containing coke that has accumulated on the surface of catalyst particles during the reaction reduces contaminant metals and produces intermediate regenerated catalyst particles. Regeneration consists of solvent washing and acid washing, wherein a polar organic solvent that is both oil-soluble and water-soluble is used in solvent washing and wherein coke is used to protect the active components introduced onto the carrier of the catalyst particles from leaching due to acid washing. The intermediate regenerated catalyst particles are regenerated by burning coke in an oxidizing atmosphere and redispersing the active components on the catalyst particles, resulting in regenerated and recycled catalyst particles with increased catalytic activity relative to the depleted catalyst particles. and The regenerated and recycled catalyst particles are recycled back to the fluidized bed hydrotreating unit.

2. The process as described in claim 1, wherein the upgraded heavy fraction comprises upgraded residue oil.

3. The process as described in claim 1, wherein the upgraded heavy fraction comprises upgraded atmospheric residue oil.

4. The process as described in claim 1, wherein the upgraded heavy fraction comprises upgraded vacuum residue.

5. The process according to any one of claims 2-4, wherein all or part of the upgraded heavy fraction is recycled to the fluidized bed hydrotreating unit.

6. A process for upgrading crude oil feedstock, comprising: The crude oil is fractionated into distillate fractions and atmospheric residue; The distillate fraction is hydrotreated in a fixed-bed hydrotreating unit to produce a hydrotreated distillate effluent. The atmospheric residue is hydrotreated in a fluidized bed hydrotreating unit with an associated fluidized bed pump and catalyst replacement system at a hydrogen partial pressure of 30-90 bar to produce an effluent, which is collected as an upgraded residue effluent; and The hydrotreated distillate is combined with the upgraded residue effluent to produce upgraded crude oil; The catalyst particles used in the fluidized bed hydrotreating unit include heterogeneous catalyst particles having an active component introduced onto a support, and are characterized by their initial catalytic activity when the catalyst particles are freshly added to the fluidized bed hydrotreating unit. Degraded catalyst particles containing contaminant metals and coke are removed from the fluidized bed hydrotreating unit, wherein the degraded catalyst particles have reduced catalytic activity compared to the initial catalytic activity; Regeneration of spent catalyst particles containing coke that has accumulated on the surface of catalyst particles during the reaction reduces contaminant metals and produces intermediate regenerated catalyst particles. Regeneration consists of solvent washing and acid washing, wherein a polar organic solvent that is both oil-soluble and water-soluble is used in solvent washing and wherein coke is used to protect the active components introduced onto the carrier of the catalyst particles from leaching due to acid washing. The intermediate regenerated catalyst particles are regenerated by burning coke in an oxidizing atmosphere and redispersing the active components on the catalyst particles, resulting in regenerated and recycled catalyst particles with increased catalytic activity relative to the depleted catalyst particles. and The regenerated and recycled catalyst particles are recycled back to the fluidized bed hydrotreating unit.

7. The process of claim 1, wherein the catalytic activity of the regenerated and recycled catalyst particles is 95% of the initial catalytic activity.

8. The process of claim 1, wherein metal accumulates on the catalyst particles during the reaction in the fluidized bed hydrotreating unit, and up to 70% by weight of the metal accumulated on the catalyst particles is removed in the regeneration step.

9. The process of claim 6, wherein the catalytic activity of the regenerated and recycled catalyst particles is 95% of the initial catalytic activity.

10. The process of claim 6, wherein metal accumulates on the catalyst particles during the reaction in the fluidized bed hydrotreating unit, and up to 70% by weight of the metal accumulated on the catalyst particles is removed in the regeneration step.

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