Method and system for introducing catalyst precursor into heavy oil using parallel mixer line and bypass line

Abstract

Systems and methods for mixing a catalyst precursor into a heavy oil include a parallel mixing line configured to receive a diluted precursor mixture (a catalyst precursor premixed with a hydrocarbon diluent) and mix it with a heavy oil to form a modulated feedstock. One of the mixing lines may be periodically offline (e.g., for maintenance) while one or more remaining mixing lines continue to form the modulated feedstock. The bypass line maintains a substantially continuous flow of heavy oil when one of the mixing lines is offline. Valves and flow meters may be used to regulate the flow through the mixing line and the bypass line. The system allows for nearly infinite amplification of the mixing process, while allowing for periodic maintenance of the system without having to make it fully offline. The catalyst precursor is mixed into heavy oil to form colloidal-sized catalyst particles in situ that have high catalytic activity that promotes beneficial upgrading reactions when hydrotreating heavy oil.

Description

Technical Field

[0001] The present invention relates to a method and system for mixing a catalyst precursor into a heavy oil feedstock prior to hydroprocessing.

[0002] Related technologies

[0003] The conversion of heavy oils into useful end products involves a great deal of processing, such as lowering the boiling point of the 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 tower bottoms and / or vacuum tower bottoms include fixed bed hydroprocessing, ebullating bed hydroprocessing, and moving bed hydroprocessing. Hydrocracking can also be carried out in a slurry bed reactor using homogeneous catalysts. Non-catalytic upgrading processes for upgrading vacuum tower bottoms include thermal cracking such as delayed coking, flexicoking, visbreaking, and solvent extraction.

[0004] The demand for more effectively utilizing low-quality heavy oil raw materials and extracting fuel value therefrom is increasing day by day. The characteristic of low-quality raw materials is to include relatively large amounts of hydrocarbons with nominal boiling points of 524°C (975°F) or above. They also contain relatively high concentrations of asphaltenes, sulfur, nitrogen and metals. The high boiling fractions derived from these low-quality raw materials usually have high molecular weights (usually represented by higher density and viscosity) and / or low hydrogen / carbon ratios, which are related to the presence of high concentrations of undesirable components (including asphaltenes and carbon residues). Asphaltenes and carbon residues are difficult to process and usually cause fouling of conventional catalysts and hydroconversion equipment because they cause the formation of coke and deposits.

[0005] Low-quality heavy oil feedstocks contain high concentrations of asphaltenes, carbon residues, sulfur, nitrogen, and metals. Examples include heavy crude oil, oil sands bitumen, and the residues left over from conventional refining processes. Residues (or "resids") may refer to atmospheric bottoms and vacuum bottoms. The boiling point of atmospheric bottoms is at least 343°C (650°F), but it is understood that the distillation point may vary from refinery to refinery, up to 380°C (716°F). The boiling point of vacuum bottoms (also called "residual oil bitumen" or "vacuum residue") is at least 524°C (975°F), but it is understood that the distillation point may vary from refinery to refinery, up to 538°C (1000°F) or even 565°C (1050°F).

[0006] By comparison, Alberta light crude contains about 9% by volume of vacuum residue, while Lloydminster heavy oil contains about 41% by volume of vacuum residue, Cold Lake bitumen contains about 50% by volume of vacuum residue, and Athabasca bitumen contains about 51% by volume of vacuum residue. By further comparison, relatively light oils from the North Sea region, such as DanskBlend, contain only about 15% by volume of vacuum residue, while lower quality European oils, such as Ural, contain more than 30% by volume of vacuum residue, and oils such as Arab Medium are even higher, containing about 40% by volume of vacuum residue.

[0007] In a given ebullated-bed system, the production rate of conversion products is typically limited by fouling. When attempts are made to increase the production of conversion products beyond certain practical limits, the fouling rates of mixers, heat exchangers, filters, and other process equipment become too rapid, requiring more frequent shutdowns for maintenance and cleaning. Refinery operators typically relate observed equipment fouling rates to measurements of deposit production and derive an operating deposit limit, above which the refinery will avoid operating an ebullated-bed hydrocracking unit. Thus, deposit generation and fouling of the equipment place a practical upper limit on conversion rates and conversion product production rates. These problems are exacerbated when lower quality heavy oil feedstocks are used.

[0008] Ebullating bed reactors utilizing a dual catalyst system consisting of a heterogeneous catalyst and a highly dispersed (e.g., colloidal or molecular) metal sulfide catalyst have been used to reduce equipment fouling and / or allow for increased production rates of converted products. The success or failure of the dual catalyst system depends on a number of variables, including the ability to disperse the catalyst precursor into the heavy oil without causing or allowing it to thermally decompose prematurely. Unless the catalyst precursor is well dispersed in the heavy oil prior to thermal decomposition, the dispersed metal sulfide catalyst particles formed in the heavy oil feedstock will have low catalytic activity and may actually cause more equipment fouling, thereby reducing its effectiveness.

[0009] For example, U.S. Pat. No. 5,372,705 to Bhattacharya et al. (“Bhattacharya”) discloses a dual catalyst system comprising a porous supported catalyst and an oil-soluble catalyst, such as a metal salt of an aliphatic carboxylic acid. However, Bhattacharya teaches that such a dual catalyst system actually causes more plugging and equipment fouling, which needs to be mitigated by the use of 5-20 weight percent aromatic heavy oil additives such as heavy cycle gas oil (HCGO) in order for the dual catalyst system to function properly without increasing equipment fouling. The need to use HCGO is evidenced by the lack of any meaningful teaching of a mixing system that would ensure that the oil-soluble catalyst is thoroughly mixed into the heavy oil feedstock prior to thermal decomposition. Furthermore, referring to it as a “catalyst” rather than a “catalyst precursor” suggests that Bhattacharya does not believe that thermal decomposition is a problem.

[0010] U.S. Patent No. 2005 / 0241991A1 ("Lott") to Lott et al. discloses a dual catalyst system comprising a porous supported catalyst and a colloidal or molecular catalyst formed in situ in a heavy oil feedstock by appropriate mixing using an oil-soluble catalyst precursor prior to thermal decomposition. Lott's examples use 100-300 ppm of a colloidal molybdenum sulfide catalyst or a molecular molybdenum sulfide catalyst to obtain beneficial results. Lott teaches that the colloidal or molecular catalyst preferentially binds to asphaltene molecules, which are difficult to hydrocracking using a porous supported catalyst because size exclusion inhibits the diffusion of the asphaltene molecules into the catalyst pores. Lott teaches that the combination of a colloidal or molecular molybdenum sulfide catalyst with an asphaltene molecule beneficially increases the conversion of asphaltene compared to using a porous supported catalyst alone.

[0011] Existing methods and systems for introducing catalyst precursors into heavy oils may not scale to accommodate larger hydroprocessing reactors. Another problem is that mixing systems often require periodic maintenance to address issues such as plugging of static inline mixers, solids buildup in filters, and seal leaks in high shear mixers. During maintenance, the entire hydroprocessing system must be shut down or at least run only with heterogeneous catalysts and not dispersed metal sulfide catalysts.

[0012] Therefore, there remains a need for more efficient and effective blending of catalyst precursors into heavy oils that address existing issues that prevent proper mixing. Summary of the invention

[0013] Disclosed herein are methods and systems for efficiently mixing catalyst precursors into a heavy oil feedstock to form a conditioned feedstock prior to hydrotreating the heavy oil using one or more hydrotreating reactors. The catalyst precursors are mixed into the heavy oil feedstock to form dispersed metal sulfide catalyst particles in situ, the catalyst particles having high catalytic activity for promoting beneficial upgrading reactions when hydrotreating the heavy oil.

[0014] The method and system use multiple parallel mixing lines and a bypass line, which are scalable for use with nearly any size hydroprocessing reactor, and the bypass line maintains a substantially constant flow rate of feed to the hydroprocessing reactor in the event that one of the mixing lines is taken offline (for example, for scheduled cleaning and maintenance). In a preferred embodiment, during normal operation, multiple parallel mixers can be operated with a symmetrical distribution of heavy oil feedstock. The bypass line is used to maintain the flow through each in-line mixer within its design capacity when another mixer is taken offline due to maintenance. In addition, the system of the present invention includes a flow control device and a flow meter, which can be used to adjust the flow to the operating mixer (or multiple mixers) during maintenance, and the flow meter ensures that the desired flow is maintained through the remaining in-line mixing lines and bypass lines.

[0015] The disclosed systems and methods allow for the use of smaller, cost-effective, commercially proven mixing equipment while ensuring that infusion of dispersed catalyst precursor is maintained, and correspondingly, a high level of process performance is maintained.

[0016] Example methods of mixing the catalyst precursor into the heavy oil include:

[0017] (1) mixing a certain amount of catalyst precursor with a certain amount of diluent to form a diluted precursor mixture;

[0018] (2) mixing the diluted precursor mixture with the heavy oil feedstock using a plurality of parallel mixing lines to form a plurality of conditioned feedstock streams, each parallel mixing line comprising one or more mixers and at least one valve for regulating flow in the mixing line;

[0019] (3) combining the conditioned feedstock streams in a common discharge line downstream of the parallel mixing lines to form a common conditioned feedstock stream;

[0020] (4) stopping flow through the blending line and directing or allowing a portion of the heavy oil feedstock to enter a bypass line, bypass the parallel blending line, and combine with the common conditioned feedstock stream in the common discharge line; and

[0021] (5) while a portion of the heavy oil feedstock is passing through the bypass line, at least one other parallel mixing line is used to continue mixing at least a portion of the diluted precursor mixture with the remaining portion of the heavy oil feedstock.

[0022] Example systems for mixing catalyst precursor into heavy oil include:

[0023] (1) at least one mixer configured to receive an amount of catalyst precursor and mix it with an amount of diluent to form a diluted precursor mixture;

[0024] (2) a plurality of parallel mixing lines configured to receive the diluted precursor mixture and mix it with the heavy oil feedstock to form a plurality of conditioned feedstock streams, each parallel mixing line comprising one or more mixers and at least one valve for regulating flow in the mixing line;

[0025] (3) a common discharge line configured to receive and combine the conditioned feedstock streams from the parallel mixing lines to form a common conditioned feedstock stream; and

[0026] (4) a bypass line configured to receive a portion of the heavy oil feedstock when flow through at least one of the parallel mixing lines is shut off and stopped, cause the portion of the heavy oil feedstock to bypass the parallel mixing lines, and combine the bypassed portion of the heavy oil feedstock with the common conditioned feedstock stream in the common discharge line,

[0027] (5) wherein the system is configured such that when one of the mixing lines is closed and the portion of the heavy oil feedstock passes through the bypass line, the remaining portion of the heavy feedstock continues to mix with the diluted precursor mixture through the at least one other parallel mixing line.

[0028] The parallel mixing lines include two or more parallel mixing lines. In some embodiments, the method and system may include two, three, four or more parallel mixing lines. In some embodiments, each mixing line includes a high shear mixer and optionally at least one other mixer, such as a static inline mixer. One or more filters (e.g., at least one strainer) may be placed along the mixing line, typically before the high shear mixer. If desired, other filtering devices and auxiliary equipment known in the art may also be included in the mixing line. A premixer zone, such as one or more static inline mixers, may be located upstream of the heavy oil feed line at the bifurcation of the parallel mixing lines.

[0029] In some embodiments, flow through multiple mixing lines can be controlled by one or more valves connected to each mixing line. For example, each mixing line can include a first valve upstream of the first mixer and a second valve downstream of the last mixer. Closing the valves isolates the mixing line to allow maintenance and cleaning without pressurized hydrocarbons entering the mixing line from one or more other mixing lines.

[0030] In order to allow a portion of the heavy oil feedstock to enter the bypass line, bypass the parallel mixing line, and enter the common discharge line, one or more valves connected to one or more operating parallel mixing lines and / or the common discharge line can be partially closed to restrict the flow, which reduces the pressure downstream of the valve and increases the pressure upstream of the valve. The pressure change caused by partially closing the valves in the discharge line and / or the common discharge line of one or more operating parallel mixing lines increases the upstream pressure, which causes a portion of the higher pressure heavy oil feedstock upstream of the parallel mixing line to flow through the bypass line. The bypass line can also include one or more valves to help control and regulate the amount and / or ratio of heavy oil flowing through the bypass line and the operating mixing line.

[0031] In some embodiments, when one of the mixing lines is shut down, the same or similar amount of the diluted precursor mixture can be mixed with the remaining amount of heavy oil feedstock to maintain the same amount and / or rate of catalyst precursor flowing through the system. In some embodiments, the flow of the heavy oil and diluted precursor mixture through one or more of the remaining operating mixing lines can be temporarily increased to account for the reduction in flow caused by shutting down one of the mixing lines. Although mixing efficiency may be reduced when one of the mixing lines is offline for maintenance, this effect is minimal and is offset by other benefits provided by the methods and systems of the present invention disclosed herein. When performing scheduled maintenance on a mixing system that includes a single mixing line, shutting down one of the multiple parallel mixing lines is far better than completely stopping mixing of catalyst precursor into the heavy oil feedstock.

[0032] To help regulate and balance the flow through the parallel mixing lines, the common discharge line, and the bypass line, at least the common discharge line and the bypass line may include a flow meter. The parallel mixing lines may each optionally include a flow meter for more accurately metering and controlling the flow through the various lines in the mixing system. In response to information obtained from the flow meter, one or more valves in the system may be opened and / or closed to regulate the flow of materials through the various lines. The valves are configured to be manually and / or automatically adjusted to regulate and balance the flow.

[0033] The mixing system may further include a buffer tank configured to receive the common conditioned feedstock stream from the common discharge line and any heavy oil feedstock from the bypass line. The buffer tank helps balance the flow of materials through the hydroprocessing system when there are differences in flow between the mixing system and the hydroprocessing reactor and other processing equipment downstream of the mixing system. The buffer tank also causes or allows additional diffusion and mixing of the catalyst precursor throughout the heavy oil feedstock before heating the conditioned feedstock to thermally decompose the catalyst precursor and form dispersed metal sulfide catalyst particles in situ in the heavy oil feedstock.

[0034] In some embodiments, a portion of the heavy oil feedstock may be used as a diluent to form a diluted precursor mixture. In a preferred embodiment, the heavy oil feedstock, when used as a diluent, is used with one or more other hydrocarbon diluents (e.g., vacuum gas oil, atmospheric gas oil, decant oil, or cycle oil) that remain flowable at lower temperatures to avoid premature decomposition of the catalyst precursor. The heavy oil feedstock or feedstock-diluent mixture may advantageously be passed through a heat exchanger to reduce its temperature prior to mixing with the catalyst precursor.

[0035] In some embodiments, a portion of the conditioned feedstock may be used as a diluent to form a diluted precursor mixture. In a preferred embodiment, the conditioned feedstock, when used as a diluent, is used with one or more other hydrocarbon diluents that remain flowable at lower temperatures to avoid premature decomposition of the catalyst precursor. The conditioned feedstock or conditioned feedstock-diluent mixture may advantageously be passed through a heat exchanger to reduce its temperature prior to mixing with the catalyst precursor.

[0036] Examples of suitable hydrocarbon diluents include, but are not limited to, vacuum gas oils (which typically have a nominal boiling range of 360-524°C (680-975°F)), decant or cycle oils (which typically have a nominal boiling range of 360-550°C (680-1022°F)), and atmospheric gas oils (which typically have a nominal boiling range of 200-360°C (392-680°F)), a portion of the heavy oil feedstock or conditioned feedstock, and other hydrocarbons having a nominal boiling point at temperatures above about 200°C.

[0037] The catalyst precursor is preferably oil soluble and has a decomposition temperature in the range of about 100°C (212°F) to about 350°C (662°F), or about 150°C (302°F) to about 300°C (572°F), or about 175°C (347°F) to about 250°C (482°F). Exemplary catalyst precursors include organometallic complexes or compounds, more specifically oil soluble compounds or complexes of transition metals and organic acids, having a decomposition temperature or decomposition temperature range high enough to avoid substantial decomposition when mixed with a heavy oil feedstock under suitable mixing conditions. When the catalyst precursor is mixed with a hydrocarbon oil diluent, it is advantageous to maintain the diluent below the temperature at which the catalyst precursor undergoes significant decomposition. One skilled in the art can select a mixing temperature profile that allows for thorough mixing of the selected precursor composition without significant decomposition prior to forming dispersed metal sulfide catalyst particles in situ.

[0038] In some embodiments, the common conditioned feedstock stream may be passed through a heater prior to entering the hydroprocessing reactor to decompose at least a portion of the catalyst precursor and form dispersed metal sulfide catalyst particles in situ in the heavy oil feedstock. For example, the conditioned feedstock may be removed from a surge tank and passed through a heater. Alternatively, or in addition, at least a portion of the conditioned feedstock may be heated within the hydroprocessing reactor itself to decompose at least a portion of the catalyst precursor and form dispersed metal sulfide catalyst particles in situ in the heavy oil feedstock. It has been found that preheating the conditioned feedstock upstream of the hydroprocessing reactor produces a more active dispersed catalyst.

[0039] In some embodiments, the dispersed metal sulfide catalyst particles are less than 1 μm in size, or less than about 500 nm in size, or less than about 250 nm in size, or less than about 100 nm in size, or less than about 50 nm in size, or less than about 25 nm in size, or less than about 10 nm in size, or less than about 5 nm in size.

[0040] In some embodiments, the heavy oil feedstock with dispersed metal sulfide catalyst particles formed in situ can be hydroprocessed under hydroprocessing conditions, wherein the dispersed metal sulfide catalyst particles promote beneficial hydrogenation and other upgrading reactions in the presence of heat and hydrogen. The hydroprocessing can be carried out by one or more hydroprocessing reactors selected from slurry phase reactors, ebullating bed reactors, and fixed bed reactors.

[0041] For example, the hydroprocessing of heavy oil can be carried out using one or more ebullated bed reactors that utilize dispersed metal sulfide catalyst particles in combination with a heterogeneous ebullated bed catalyst to produce upgraded heavy oil. Instead of or in addition to one or more ebullated bed reactors, the hydroprocessing of heavy oil can also be carried out using one or more slurry phase reactors that utilize dispersed metal sulfide catalyst particles as the sole catalyst or in combination with a conventional slurry catalyst and / or one or more fixed bed reactors that utilize dispersed metal sulfide catalyst particles in combination with a heterogeneous fixed bed catalyst.

[0042] After the heavy oil is hydrotreated, the upgraded heavy oil can be separated into one or more low boiling hydrocarbon fractions and one or more liquid hydrocarbon fractions. For example, one or more thermal separation units, interstage separators that cause pressure drop, atmospheric distillation columns, or vacuum distillation columns can be used to separate the upgraded heavy oil.

[0043] These and other advantages and features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to further illustrate the above and other advantages and features of the present invention, the present invention will be described in more detail with reference to the specific embodiments of the present invention shown in the accompanying drawings. It should be understood that these drawings generally depict only typical embodiments of the present invention and should not be considered as limiting the scope thereof. The present invention will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:

[0045] Figure 1 The hypothetical molecular structure of asphaltenes is depicted;

[0046] Figure 2 An exemplary ebullated-bed hydroprocessing system using a dual catalyst system that can be used to hydroprocess heavy oil is schematically illustrated;

[0047] Figure 3A schematically illustrates an exemplary ebullating bed reactor and a separator unit for separating volatile materials from non-volatile materials;

[0048] Figure 3B Schematically illustrates an exemplary slurry phase reactor and a separator unit for separating volatile materials from non-volatile materials;

[0049] Figure 3C An exemplary hydroprocessing system is schematically illustrated, the system comprising a slurry phase reactor, a separator unit to separate volatile materials from non-volatile materials, and a fixed bed reactor for further hydroprocessing the non-volatile materials;

[0050] Figure 4A An exemplary ebullated-bed hydroprocessing system having multiple ebullated-bed reactors and other processing equipment is schematically illustrated.

[0051] Figure 4B An exemplary ebullated bed hydroprocessing system is schematically illustrated, which includes a Figure 4A A plurality of ebullating bed reactors, and an interstage separator between two reactors;

[0052] Figure 5A-5B schematically illustrates an exemplary mixing system having two parallel mixing lines and one bypass line;

[0053] Figure 6A-6B schematically illustrates an exemplary mixing system having three parallel mixing lines and one bypass line; and

[0054] Figure 7A-7B An exemplary mixing system having four parallel mixing lines and one bypass line is schematically illustrated. DETAILED DESCRIPTION

[0055] 1. Introduction

[0056] Disclosed herein are methods and systems for mixing catalyst precursors into a heavy oil feedstock prior to hydroprocessing the heavy oil. The disclosed mixing methods and systems can be scaled up to accommodate hydroprocessing reactors of varying sizes and provide the ability to perform maintenance on the mixing line without shutting down the entire mixing system. This is accomplished through multiple parallel mixing lines and a bypass line that allows the mixing line to be shut down and taken offline for maintenance while the bypass line continues to provide a substantially constant flow of heavy oil to the system for hydroprocessing.

[0057] The disclosed mixing method and system provide efficient mixing of dispersed catalyst precursors for a hydroconversion unit such as an ebullated bed unit, a fixed bed unit or a slurry reactor unit. The process is particularly suitable for large hydroconversion units, which can be designed as a single group or multiple groups, where the large capacity of the hydroconversion unit makes it difficult to provide a single mixing system for the dispersed catalyst precursors. To address this difficulty, the method and system of the present invention include two or more parallel mixing lines, each of which is equipped with a high shear mixing device of conventional size and design.

[0058] In addition to providing a method for using conventional mixing equipment for high capacity hydroconversion units, the present invention also has the advantage of facilitating scheduled maintenance of the mixing equipment without interrupting the mixing of catalyst precursor into the heavy oil feedstock. This is achieved by providing a bypass line for the mixing system, allowing a portion of the heavy oil feedstock to the hydroconversion unit to bypass the mixing system when the mixing line is offline for maintenance, with the remaining heavy oil feedstock being processed by the remaining online mixing line without interrupting the mixing of the catalyst precursor with the heavy oil.

[0059] As another feature of the mixing method and system of the present invention, each parallel mixing line can be equipped with one or more flow control devices. The common discharge line that receives and merges the modulated feedstock streams from the various mixing lines can also include a flow control device. The operation of one or more flow control devices may be beneficial or critical to maintaining an appropriate flow balance between the remaining online mixing lines and the bypass line during maintenance intervals. At least one flow control device is located downstream of the online high shear mixer, such as in each parallel mixing line and / or the common discharge line, and can be a manual valve, an automatic control valve, etc. During maintenance operations, one or more flow control devices are used to partially restrict the discharge flow from the online high shear mixer, thereby causing or allowing a desired portion of the heavy oil feedstock to flow through the bypass line. In the absence of such a required flow control device, the online high shear mixer can generate sufficient positive discharge pressure so that the required flow through the bypass line is not started or maintained because the pressure in the common discharge line will be higher than the pressure in the pipeline upstream of the parallel high shear mixer and the bypass line.

[0060] Another feature of the mixing method and system of the present invention is the use of one or more flow measurement devices (flow meters) to manage the flow of the entire mixing system, which flow measurement devices can be used in conjunction with one or more flow control devices (e.g., valves). One aspect of flow control is provided by a flow measurement device and a flow control device installed on a common discharge line downstream of the parallel mixing lines, as well as a flow control device and an optional flow measurement device on a bypass line. Flow control can optionally include one or more alternative or additional flow measurement devices and / or valves on each mixing line. Accurate and real-time flow measurement and control by measuring and adjusting the flow through the various pipelines ensures that the desired flow through the various pipelines and the entire system is maintained, and provides critical low flow protection for the mixer.

[0061] Additional features and advantages of the hybrid method and system of the present invention are summarized in the following paragraphs.

[0062] Newer hydroconversion units can be very large, and in order to properly disperse the dispersed catalyst precursor mixture in the heavy oil feedstock to accommodate a very large hydroconversion unit, it may be impractical to build a single train mixing device. A mixing system having two or more parallel mixing lines facilitates the use of a practical size mixing device for such larger hydroconversion units.

[0063] Even for smaller hydroconversion units where a single train mixing device may be feasible, maintenance of the mixing device will cause the entire decentralized catalyst mixing system to be offline. This reduces the performance of the hydroconversion unit during the maintenance interval because there is no online backup to continue mixing the catalyst precursor into the heavy oil. In addition to allowing the mixing line to be maintained while continuing to produce the conditioned feedstock, the disclosed mixing system allows the use of a smaller capacity mixing line instead of alternating full-scale mixing lines back and forth to perform the entire mixing process. In the latter case, one of the full-scale mixing lines remains dormant and inoperative while the other mixing line is operating, which is a waste of mixing resources.

[0064] During normal operation of the parallel mixing lines, the system advantageously or preferably operates with a symmetrical distribution of feedstock flow (i.e., equal flow through each parallel mixing line). Advantageously or preferably, the parallel mixing lines are designed with symmetrical piping and mixing equipment so that the pressure drop through each parallel mixing line is substantially equal and equal flow between different mixing lines can be maintained.

[0065] When using a mixing system with a simple arrangement of parallel mixing lines, a problem may arise when one of the parallel mixing lines is taken offline for maintenance while the other mixing lines continue to operate. In this case, the remaining online mixing lines may not have sufficient capacity to accommodate the total heavy oil feed rate required by the hydroconversion unit. This may require a reduction in the heavy oil production of the hydroconversion unit during the maintenance period, which is undesirable because it will correspondingly reduce the productivity of the unit.

[0066] To address the above problems, the mixing method and system of the present invention includes a bypass line. During the interval when one of the parallel mixing lines is offline, the portion of the heavy oil feedstock that would otherwise pass through the mixing line can be diverted through the bypass line instead. This allows the total production of the heavy oil feedstock to be substantially maintained during maintenance. Advantageously or preferably, during the maintenance interval, the flow of the heavy oil feedstock and the diluted precursor mixture is distributed to maximize the flow through the remaining online high shear mixer (consistent with the capacity limitations of the mixer), and the remaining heavy oil that exceeds the mixing capacity of the remaining online mixing line is transported through the bypass line.

[0067] By maintaining the maximum possible feedstock flow through the remaining online mixing lines during maintenance intervals, uninterrupted mixing of the catalyst precursor with the majority of the heavies can be maintained. During maintenance, the full amount of dispersed catalyst precursor can often continue to be used by temporarily redirecting a portion of the catalyst precursor (originally injected through the offline maintenance mixing line) to the remaining online mixing lines. Although mixing efficiency may be reduced when one of the mixing lines is offline for maintenance, this effect is minimal and is offset by other benefits provided by the inventive methods and systems disclosed herein.

[0068] One potential problem with the successful operation of a bypass line is ensuring the desired distribution of the heavy oil feedstock flow when the mixing line is offline for maintenance. As described above, the preferred flow distribution is to maximize the flow through the remaining online mixing line under capacity constraints and direct the remainder of the flow through the bypass line. However, the operation of the high shear mixer is similar to a pump, so that due to the action of the mixer, the pressure generated in the discharge line (downstream of the high shear mixer) is higher than the pressure generated in the suction line (upstream of the high shear mixer). When the bypass line is opened, in the absence of one or more flow control devices, it is impossible for the feedstock to establish a forward flow through the bypass line because the pressure downstream of the remaining online high shear mixer will be higher than the upstream pressure in the suction line. In fact, in the absence of one or more flow control devices or valves, the hydrocarbon flow may appear in the bypass line in the opposite direction, creating an undesirable circulation loop in the mixing system.

[0069] In order to solve the above problems and achieve successful operation of the bypass line during maintenance intervals, the disclosed method and system include one or more flow control devices. These can be manual valves, automatic control valves, etc. Preferably, the flow control device is located on the common discharge line downstream of the confluence of the parallel mixing pipelines. Alternatively or in addition, the flow control device can be located on each mixing line downstream of the high shear mixer. When the mixing line is offline due to maintenance, the flow control device in the common discharge line and / or the remaining online mixer is adjusted to partially limit the discharge flow from the online mixing line, which changes the pressure distribution in the mixing system. The pressure in the feedstock pipeline upstream of the mixing line increases, which enables the heavy oil feedstock to flow forward through the bypass line as needed. By appropriately adjusting the flow control device, the desired flow distribution between the remaining online mixing line and the bypass line can be maintained.

[0070] An additional optional feature of the present invention is the use of one or more flow measuring devices. Preferably, there are flow measuring devices on the common discharge line and / or on the parallel mixing lines downstream of the high shear mixer, and upstream of the junction of the bypass line with the common discharge line. This allows the heavy oil flow through the high shear mixer to be monitored, ensuring that the required flow is maintained through the in-line high shear mixer during normal operation and maintenance operation.

[0071] An optional flow meter may also be installed on the bypass line.Another optional feature of the present invention is a flow control device on the bypass line, which can be combined with other flow control devices to provide flow distribution flexibility.

[0072] Below Figures 5A-7B Further illustrating the disclosed hybrid method and system. For example, Figure 5A-5B Embodiments of mixing systems and methods using two parallel mixing lines and one bypass line are shown. According to some embodiments, the flow control device can be a valve that can be located on the common discharge line downstream of where the mixer discharge lines join each other, but upstream of where the bypass line joins the common discharge line. When both high shear mixers are operating with a preferred symmetrical flow distribution, the flow control valve will typically be fully open during normal operation. When one high shear mixer is offline for maintenance, the flow control valve in the common discharge line and / or the remaining mixing lines downstream of the high shear mixer is partially closed to limit the flow in the remaining parallel mixing lines and / or the common discharge line and increase the upstream pressure. This causes or allows a desired portion of the heavy oil feedstock to flow through the bypass line while still allowing a majority of the heavy oil feedstock to flow through the remaining online high shear mixer, which can be increased during maintenance intervals based on the capacity of the mixer. Figure 5A Also shown is a flow measurement device (flow meter) located on the common discharge line upstream of the flow control valve, which is located upstream of the junction of the bypass line with the common discharge line. Figure 5A-5B Also shown are optional flow measurement devices on the bypass line and optional flow measurement devices on each mixing line.

[0073] Figure 6A-6B The diagram is similar to Figure 5A-5B An embodiment of a mixing system and method as shown in but including three parallel mixing lines. Figure 7A-7B The diagram is similar to Figure 5A-5B and 6A-6B but including an embodiment of the mixing system and method of four parallel mixing pipelines.

[0074] In the right Figures 5A-7BBefore explaining in more detail the features shown in FIG. 1 , which illustrates an example mixing system that can be used with the disclosed mixing method, reference is first made to proposed definitions of certain terms and then to the Figure 1-4B and existing hydroprocessing reactors and systems, with which the hybrid methods and systems of the present invention may be combined and / or integrated.

[0075] II. Definitions

[0076] "Asphaltenes" and "asphaltenes" refer to materials in heavy oil that are insoluble in paraffinic solvents such as propane, butane, pentane, hexane and heptane. Asphaltenes can include sheets of fused ring compounds held together by heteroatoms such as sulfur, nitrogen, oxygen and metals. Asphaltenes broadly include a variety of complex compounds with 80 to 1200 carbon atoms, with the major molecular weights ranging from 1200 to 16900 as determined by solution techniques. About 80-90% of the metals in crude oil are contained in the asphaltene fraction, which, combined with a higher concentration of non-metallic heteroatoms, makes the asphaltene molecules more hydrophilic and less hydrophobic than other hydrocarbons in heavy oil residue.

[0077] A hypothetical asphaltene molecular structure developed by A.G.Bridge and colleagues at Chevron Figure 1 As shown. Asphaltenes are often defined based on the results of an insolubles analysis, and more than one definition of asphaltenes may be used. Specifically, a common definition of asphaltenes is heptane insolubles minus toluene insolubles (i.e., asphaltenes are soluble in toluene; sediments and residues that are insoluble in toluene are not counted as asphaltenes). Asphaltenes defined in this manner may be referred to as "C7 asphaltenes." Another definition is to measure pentane insolubles minus toluene insolubles, commonly referred to as "C5 asphaltenes." In the examples of the present invention, the C7 asphaltenes definition is used, but the C5 asphaltenes definition may be easily replaced.

[0078] "Fouling" refers to the formation of undesirable phases (foulants) that interfere with processing. Foulants are typically carbonaceous materials or solids (e.g., sediments) that settle and accumulate within process equipment. Equipment fouling can result in production losses due to equipment downtime, reduced equipment performance, increased energy consumption due to the insulating effects of fouling deposits in heat exchangers or heaters, increased equipment cleaning and maintenance costs, reduced fractionator efficiency, and reduced reactivity of heterogeneous catalysts. Hydroprocessing equipment, such as blending lines, require periodic maintenance to remove deposits and other foulants.

[0079] The "equipment fouling rate" of a hydrocracking reactor can be determined by at least one of the following: (i) the frequency of required heat exchanger cleaning; (ii) the frequency of switching to a backup heat exchanger; (iii) the frequency of filter replacement; (iv) the frequency of strainer cleaning or replacement; (v) the rate of decrease in equipment surface temperature, the equipment including equipment selected from the group consisting of a heat exchanger, a separator or a distillation column; (vi) the rate of increase in furnace tube metal temperature; (vii) the rate of increase in the calculated fouling thermal resistivity of the heat exchanger and furnace; (viii) the rate of increase in heat exchanger pressure differential; (ix) the frequency of cleaning atmospheric and / or vacuum distillation columns; or (x) the frequency of maintenance turnarounds.

[0080] "Heavy oil" and "heavy oil feedstock" refer to heavy crude oil, oil sands bitumen, barrel bottoms, and residues left over from the oil refining process, such as visbreaker bottoms, and any other low-quality material that contains a large amount of high-boiling hydrocarbon fractions and / or contains a large amount of asphaltenes, which can deactivate heterogeneous catalysts and / or cause or contribute to the formation of coke precursors and deposits. Examples of heavy oils include, but are not limited to, Lloydminster heavy oil, Cold Lake bitumen, Athabasca bitumen, atmospheric tower bottoms, vacuum tower bottoms, residue (or "residual oil"), residual oil bitumen, vacuum residue oil (e.g., Ural VR, Arab Medium VR, Athabasca VR, Cold Lake VR, Maya VR, and Chichimene VR), pyrolysis oil, deasphalted liquid obtained by solvent deasphalting, asphaltene liquid obtained as a by-product of deasphalting, and non-volatile liquid fractions remaining after distillation, thermal separation, solvent extraction of crude oil, tar sands bitumen, liquefied coal, oil shale, or coal tar feedstocks, etc. As a further example, the boiling point of the atmospheric column bottoms is at least 343°C (650°F), but it is understood that boiling points may vary from refinery to refinery and may be as high as 380°C (716°F). The nominal boiling point of the vacuum column bottoms may be at least 524°C (975°F), but it is understood that the cut points may vary from refinery to refinery and may be as high as 538°C (1000°F) or even 565°C (1050°F).

[0081] "Hydrocracking" and "hydroconversion" refer to processes where the primary purpose is to reduce the boiling range of heavy oils and where a large portion of the heavy oil is converted to products having a boiling range lower than the original feed. Hydrocracking or hydroconversion generally involves splitting larger hydrocarbon molecules into smaller molecular fragments having a smaller number of carbon atoms and a higher hydrogen-to-carbon ratio. The mechanism by which hydrocracking occurs generally involves the formation of hydrocarbon free radicals during thermal cracking, followed by the capping of the free radicals with hydrogen. The hydrogen atoms or free radicals that react with the hydrocarbon free radicals during the hydrocracking process may be generated at or from active catalyst sites.

[0082] "Hydrotreating" refers to a process whose primary purpose is to remove impurities such as sulfur, nitrogen, oxygen, halides and trace metals from the feedstock and to saturate olefins and / or stabilize hydrocarbon radicals by reacting them with hydrogen rather than reacting them with themselves. The primary purpose is not to change the boiling range of the feedstock. Hydrotreating is typically performed using a fixed bed reactor, but other hydroprocessing reactors such as ebullated bed hydrotreaters and slurry phase hydrotreaters may also be used.

[0083] "Hydrocracking" and "hydroconversion" may also include the removal of sulfur and nitrogen from the feedstock, as well as olefin saturation and other reactions typically associated with "hydrotreating." The terms "hydrotreating" and "hydroconversion" shall broadly refer to the "hydrocracking" and "hydrotreating" processes, which define both ends of the range and all processes in between along the range.

[0084] "Hydrocracking reactor" means any vessel in which the hydrocracking (i.e., lowering the boiling range) of a feedstock in the presence of hydrogen and a hydrocracking catalyst is the primary purpose. A hydrocracking reactor is characterized by having one or more inlets for introducing heavy oil and hydrogen therein, an outlet from which an upgraded feedstock or material is removed, and sufficient thermal energy to promote the splitting of larger hydrocarbon molecules into smaller molecules, resulting in the formation of hydrocarbon free radicals. Examples of hydrocracking reactors include, but are not limited to, slurry phase reactors (i.e., two-phase gas-liquid systems), ebullating bed reactors (i.e., three-phase gas-liquid-solid systems), and fixed bed reactors (i.e., three-phase systems comprising a liquid feed trickling downward or flowing upward over a fixed bed of solid heterogeneous catalyst, with hydrogen typically flowing concurrently with the heavy oil, but countercurrent is also possible).

[0085] "Hydrocracking temperature" refers to the minimum temperature required to cause significant hydrocracking of the heavy oil feedstock. Generally, the hydrocracking temperature is preferably in the range of about 399°C (750°F) to about 460°C (860°F), more preferably in the range of about 418°C (785°F) to about 443°C (830°F), and most preferably in the range of about 421°C (790°F) to about 440°C (825°F).

[0086] "Gas-liquid slurry phase hydrocracking reactor" refers to a hydroprocessing reactor comprising a continuous liquid phase and a gaseous dispersed phase, which forms a "slurry" of gas bubbles in the liquid phase. The liquid phase typically comprises a hydrocarbon feedstock, which may contain a low concentration of dispersed metal sulfide catalyst particles, which may appear as a colloid or pseudosolute, and the gas phase typically comprises hydrogen, hydrogen sulfide, and vaporized low-boiling hydrocarbon products. The liquid phase may optionally include a hydrogen donor solvent.

[0087] When a solid catalyst is used with a liquid and a gas, a "gas-liquid-solid three-phase slurry hydrocracking reactor" is used. The gas may contain hydrogen, hydrogen sulfide, and vaporized low-boiling hydrocarbon products. The term "slurry phase reactor" broadly refers to two types of reactors (e.g., a reactor with dispersed metal sulfide catalyst particles, a reactor with micron-sized or larger particle catalysts, and reactors including both types).

[0088] "Solid heterogeneous catalyst," "heterogeneous catalyst," and "supported catalyst" refer to catalysts typically used in ebullating bed hydroprocessing systems and fixed bed hydroprocessing systems, including catalysts designed primarily for hydrocracking, hydroconversion, hydrodemetallization, and / or hydrotreating. Heterogeneous catalysts typically include a catalyst support structure having a large surface area and interconnecting channels or pores, and fine active catalyst particles, such as sulfides of cobalt, nickel, tungsten, and / or molybdenum, dispersed within the channels or pores. The pores of the support are typically of a limited size to maintain the mechanical integrity of the heterogeneous catalyst and to prevent decomposition and excessive formation of fines in the reactor. Heterogeneous catalysts can be prepared as cylindrical particles, cylindrical extrudates, other shapes, such as trilobes, rings, saddles, etc., or spherical solids.

[0089] "Dispersed metal sulfide catalyst particles" and "dispersed catalyst" refer to catalyst particles having a particle size of less than 1 μm (submicron or submicron), preferably less than about 500 nm, or less than about 250 nm, or less than or equal to about 100 nm, or less than or equal to about 50 nm, or less than about 25 nm, or less than about 10 nm, or less than 5 nm. The term "dispersed metal sulfide catalyst particles" may include molecules or molecularly dispersed catalyst compounds. "Dispersed metal sulfide catalyst particles" generally do not include metal sulfide particles greater than 1 μm and agglomerates of metal sulfide particles.

[0090] "Molecularly dispersed catalyst" refers to a catalyst compound that is substantially "dissolved" or dissociated from other catalyst compounds or molecules in a hydrocarbon feedstock or suitable diluent. It can include very small catalyst particles that contain a few catalyst molecules bound together (e.g., 15 molecules or less).

[0091] "Residual dispersed catalyst particles" and "residual dispersed metal sulfide catalyst particles" refer to catalyst particles that remain in the hydrocarbon product when transferred from one container to another (e.g., from a hydroprocessing reactor to a separator and / or other hydroprocessing reactors). Residual dispersed metal sulfide catalyst particles may also remain in the liquid residual fraction or asphalt after the hydrocarbon product is separated into a distillate and a residual liquid or asphalt, for example, by flash separation, thermal separation, atmospheric distillation, vacuum distillation, or vacuum stripping.

[0092] "Conditioned feedstock" means a hydrocarbon feedstock into which a catalyst precursor has been combined and thoroughly mixed so that when the catalyst precursor decomposes and forms an active catalyst, the catalyst will comprise dispersed metal sulfide catalyst particles formed in situ in the feedstock. Conditioned feedstocks include conditioned heavy oils.

[0093] "Upgrade," "upgrading," and "upgraded" when used to describe a feedstock or a resulting material or product that is or has been subjected to hydroprocessing, refers to one or more of a reduction in feedstock molecular weight, a reduction in the boiling range of the feedstock, a reduction in asphaltene concentration, a reduction in hydrocarbon radical concentration, and / or a reduction in the amount of impurities (e.g., sulfur, nitrogen, oxygen, halides, and metals).

[0094] "Severity" refers to the energy introduced into the heavy oil during the hydroprocessing process, which is related to the operating temperature of the hydroprocessing reactor (i.e., higher temperatures are associated with higher severity, while lower temperatures are associated with lower severity at the same or similar throughput) and the duration or residence time. An increase in severity generally increases the amount of conversion products produced by the hydroprocessing reactor, including both desired products and undesired products. Conversion rate and throughput also affect severity. For example, when temperature is increased and throughput remains unchanged, conversion rate will generally increase for a given feedstock. In order to maintain temperature while increasing throughput (i.e., increasing liquid hourly space velocity), which reduces the residence time of the heavy oil in the reactor, more thermal energy must be added to the system to offset the cooling effect of feeding a larger amount of initially cooler heavy oil to the reactor per unit time.

[0095] Desired conversion products include hydrocarbons with reduced molecular weight, reduced boiling point, and reduced specific gravity, which may include final products such as naphtha, diesel, jet fuel, kerosene, wax, fuel oil, etc. Other desired conversion products include high boiling hydrocarbons that can be further processed using conventional refining and / or distillation processes. A bottoms product of sufficient quality to be used as a fuel oil is another example of a desirable conversion product.

[0096] Undesirable conversion products include coke, sediments, metals and other solid materials (which can be deposited on hydroprocessing equipment and cause fouling, such as reactors, separators, filters, pipelines, towers, internal parts of heat exchangers) and heterogeneous catalysts. Undesirable conversion products can also refer to unconverted residual oil remaining after distillation, such as atmospheric tower bottoms ("ATB") or vacuum tower bottoms ("VTB"), especially residual oils of too low quality to be used as fuel oil or other desired uses. Minimizing unwanted conversion products reduces equipment fouling and the downtime required for cleaning equipment. However, in order to operate downstream separation equipment properly and / or provide a liquid transport medium for carrying coke, sediments, metals and other solid materials (which may otherwise be deposited on the equipment and fouling, but can be transported away by the remaining residual oil), a desired amount of unconverted residual oil may be present.

[0097] In addition to temperature, "severity" can be related to one or both of "conversion" and "production volume". Whether the increase in severity involves an increase in conversion and / or an increase or decrease in production volume may depend on the quality of the heavy oil feedstock and / or the mass balance of the entire hydroprocessing system. For example, when it is desired to convert a larger amount of feed material and / or provide a larger amount of material to downstream equipment, the increased severity may mainly involve an increased production volume without necessarily increasing the conversion fraction. This can include situations where the residual oil fraction (ATB and / or VTB) is sold as fuel oil, and increasing the conversion rate without increasing production may reduce the amount of the product. In the case of wishing to increase the ratio of upgraded materials to the residual oil fraction, it may be desirable to mainly increase the conversion rate without necessarily increasing production volume. When the quality of the heavy oil introduced into the hydroprocessing reactor fluctuates, it may be necessary to selectively increase or decrease one or both of the conversion rate and production volume to maintain the desired ratio of upgraded materials to the residual oil fraction and / or the desired absolute amount of the final product being produced.

[0098] "Conversion" and "conversion fraction" refer to the proportion of heavy oil converted to low boiling and / or low molecular weight materials, usually expressed as a percentage. Conversion is expressed as the percentage of the initial residual oil content (i.e., components with boiling points above the defined residual oil cut point) converted to products with boiling points below the defined cut point. The definition of the residual oil cut point can vary and can nominally include 524°C (975°F), 538°C (1000°F), 565°C (1050°F), etc. It can be measured by distillation analysis of the feed and product streams to determine the concentration of components with boiling points above the defined cut point. The conversion fraction is expressed as (FP) / F, where F is the amount of residual oil in the combined feed stream and P is the amount in the combined product stream, where both the feed and product residual oil contents are based on the same cut point definition. The amount of residual oil is usually defined based on the mass of components with boiling points above the defined cut point, but a volume or molar definition can also be used.

[0099] The conversion of asphaltenes may differ from the total conversion of heavy oil. For the purposes of this disclosure, a useful definition of asphaltene conversion is based on the relative amounts of asphaltenes in the fresh feedstock and the upgraded product and may be defined by the following formula, with the result being a decimal between 0 and 1, which may be converted to a percentage by multiplying by 100:

[0100] Conversion = [asphaltene (fresh feed) - asphaltene (product)] / asphaltene (fresh feed). The asphaltene content in the recycle stream is internal to the process. Recycle buildup of asphaltene can occur when the conversion of asphaltene is too low compared to the overall conversion of the heavy oil.

[0101] "Throughput" refers to the amount (mass or volume) of feed material introduced into a hydroprocessing reactor per unit time. Throughput can be expressed in terms of volume, such as barrels per hour or day, or in terms of mass, such as metric tons per hour or day. In common use, throughput is defined as the mass or volume feed rate of only the heavy oil feedstock itself (e.g., vacuum tower bottoms, etc.). This definition does not generally include the amount of diluent or other components that may be added to or included in the total feed to the hydroconversion unit, although definitions that include those other components may also be used.

[0102] "Space velocity" and "liquid hourly space velocity" are related to the throughput of a particular reactor or reactor size, but are normalized to remove the size (volume) of the reactor. Thus, a larger reactor can have twice the throughput, but the space velocity is the same as a reactor half the size. Thus, for a given reactor size, an increase in space velocity is generally proportional to an increase in throughput. Space velocity is inversely proportional to the residence time of the heavy oil in a reactor of a given reactor size.

[0103] The "production rate of conversion product" is an absolute rate, which may be expressed in terms of volume, such as barrels per hour or day, or in terms of mass, such as metric tons per hour or day. The "production rate of conversion product" should not be confused with yield or efficiency, which are sometimes incorrectly referred to as "rates" (e.g., production rate per unit feed rate, or production rate per unit of conversion feed). It should be understood that the actual values ​​of both the initial production rate of conversion product and the increased production rate of conversion product are specific to a single production facility and depend on the capacity of that facility. Therefore, it is valid to compare the production rates of related units or facilities before and after conversion, but not to compare different units or facilities with different capacities.

[0104] III. Example Hydroprocessing System

[0105] Figure 2-4BExample hydroprocessing reactors and systems are shown that can be used with the disclosed hybrid methods and systems and benefit from being combined or integrated with the disclosed hybrid methods and systems. The disclosed hybrid methods and systems can be used or placed anywhere in the illustrated hydroprocessing system. Typically, the hybrid system is typically located upstream of a hydroprocessing reactor that is configured to operate using dispersed metal sulfide catalyst particles that are generated in situ in heavy oil from a catalyst precursor. The disclosed methods and systems are used to continuously introduce a catalyst precursor into a heavy oil and form dispersed metal sulfide catalyst particles in situ in the heavy oil, while being scaled to accommodate hydroprocessing reactors and systems of different sizes and facilitating regular maintenance of the hybrid equipment without having to shut down the entire hybrid system.

[0106] The feedstocks that can be used in the disclosed hybrid methods and systems and hydroprocessed using one or more hydroprocessing reactors can include any desired fossil fuel feedstock and / or fractions thereof, including but not limited to one or more of heavy crude oil, oil sands bitumen, bottom of the barrel fractions from crude oil, atmospheric tower bottoms, vacuum tower bottoms, coal tar, liquefied coal, other residual oil fractions, pyrolysis oil, and deasphalted oil. Heavy oil and residual oil can include a significant proportion of high boiling hydrocarbons (i.e., nominal temperatures equal to or greater than 343°C (650°F), more specifically nominal temperatures equal to or greater than about 524°C (975°F) and / or asphaltenes. As described above and as Figure 1 As shown, asphaltenes are complex hydrocarbon molecules, including relatively low hydrogen-to-carbon ratios and a large number of fused aromatic and cycloalkane rings with paraffin side chains. The sheets composed of fused aromatic and cycloalkane rings are held together by heteroatoms such as sulfur or nitrogen, polymethylene bridges, thioether bonds and / or vanadium and nickel complexes. Asphaltenes also contain more sulfur and nitrogen than the rest of the crude oil or vacuum residue, and they also contain higher concentrations of carbon-forming compounds (i.e., compounds that form coke precursors and deposits).

[0107] Figure 2An example ebullated bed hydroprocessing system 200 is schematically illustrated, which utilizes a dual catalyst system of dispersed metal sulfide catalyst particles and a heterogeneous ebullated bed catalyst. The ebullated bed hydroprocessing system 200 includes an ebullated bed reactor 230 and a separator 204 (e.g., a hot separator, an interstage pressure difference separator, or a distillation column). The ebullated bed reactor 230 is similar to the reactor used in the LC-refining hydrocracking system developed by CE Lummus. The catalyst precursor 202 is mixed with a hydrocarbon diluent 204 in one or more premixers 206 to form a diluted precursor mixture 209. The diluted precursor mixture 209 is added to and mixed with a heavy oil feedstock 208 using a mixing system 210 (i.e., as disclosed herein, having multiple parallel mixing lines and bypass lines) to form a conditioned feedstock 211.

[0108] The conditioned feedstock 211 is fed into a buffer tank 212 having a pump circulation loop 214 to achieve further mixing and dispersion of the catalyst precursor 202 in the feedstock 208. A bypass line (not shown) returns any heavy oil that bypasses the mixing line (not shown) to a common discharge line (not shown) and / or feeds the heavy oil directly into the buffer tank 212. The buffer tank 212 and the pump circulation loop 214 advantageously further mix the catalyst precursor into the heavy oil (including the heavy oil from the bypass line). The conditioned feedstock from the buffer tank 212 is pressurized by one or more pumps 216, passes through a preheater 218, and is fed into the ebullated bed hydroprocessing reactor 230 together with hydrogen 220 through one or more inlets 236, which are located at or near the bottom of the ebullated bed reactor 230.

[0109] The ebullated bed reactor 230 includes a hydrocarbon material 226 and an expanded catalyst zone 242, the expanded catalyst zone 242 including a heterogeneous catalyst 244 typically used in an ebullated bed reactor, which is maintained in an expanded or fluidized state against gravity by the upward movement of liquid hydrocarbons 226 and gas. A lower heterogeneous catalyst-free zone 248 is located below the distributor grid plate defining the bottom of the expanded catalyst zone 242, and an upper heterogeneous catalyst-free zone 250 is located above the expanded catalyst zone 242. Dispersed metal sulfide catalyst particles 224 are dispersed throughout the hydrocarbon material 226 within the ebullated bed reactor 230, including in the expanded catalyst zone 242 and the heterogeneous catalyst-free zones 248, 250, so that they can be used to promote beneficial upgrading reactions in the absence of a heterogeneous catalyst 244.

[0110] The funnel-shaped recycle cup 256 fed into the recycle channel 252 connected to the ebullating pump 254 continuously recycles the hydrocarbon material 226 from the upper heterogeneous catalyst-free zone 250 to the lower heterogeneous catalyst-free zone 248. The downward suction of the recycle cup 256 at the top of the recycle channel 252 draws the hydrocarbon material 226 containing the dispersed catalyst particles 224 from the upper heterogeneous catalyst-free zone 250 downward through the recycle channel 252 and into the bottom of the ebullating bed reactor 230 via the ebullating pump 254. The recycled hydrocarbon material 226 is mixed with a new feed containing dispersed metal sulfide catalyst particles (and / or catalyst precursor) and hydrogen 220.

[0111] Fresh heterogeneous catalyst 244 may be periodically introduced into the ebullating bed reactor 230 via catalyst inlet conduit 258, and spent heterogeneous catalyst 244 may be periodically removed via catalyst removal conduit 260. Dispersed metal sulfide catalyst particles 224 provide additional catalytic activity within the expanded catalyst zone 242, recycle passage 252, and lower and upper heterogeneous catalyst-free zones 248, 250. The catalytic addition of hydrogen to the hydrocarbons external to the heterogeneous catalyst 244 reduces or minimizes the formation of deposits and coke precursors, which are often responsible for deactivation of the heterogeneous catalyst and lead to fouling of the system.

[0112] The ebullated bed reactor 230 also includes an outlet 238 located at or near the top through which converted material 240 is discharged. The converted material 240 is introduced into the separator 204, which separates the volatile fraction 205 from the residual oil fraction 207. The volatile fraction 205 is withdrawn from the top of the hot separator 204, and the residual oil fraction 207 is withdrawn from the bottom of the hot separator 204. The residual oil fraction 207 contains residual dispersed metal sulfide catalyst particles, schematically represented as catalyst particles 224". If desired, at least a portion of the residual oil fraction 207 can be recycled back to the ebullated bed reactor 230 to form a portion of the feed material and provide additional dispersed metal sulfide catalyst particles. Alternatively, the residual oil fraction 207 can be further processed using downstream processing equipment (e.g., another ebullated bed reactor, a distillation column, a deasphalting unit, etc.). A portion of the residual oil fraction 207 can be used as a diluent to form a catalyst precursor mixture.

[0113] Figure 3AAnother type of ebullated bed hydroprocessing reactor 310 is schematically illustrated, having a different recycle system typical of the H-Oil hydrocracking system developed by Hydrocarbon Research, Inc. and currently licensed by Axens. The ebullated bed reactor 310 includes an inlet 312 through which a heavy oil feedstock 314 and pressurized hydrogen 316 are introduced, and an outlet 318 through which upgraded hydrocarbon material 320 is withdrawn.

[0114] An expanded catalyst zone 322 containing a heterogeneous catalyst 324 is bounded by a distributor grid plate 326 and an upper end 329, the distributor grid plate 326 separating the expanded catalyst zone 322 from a lower catalyst-free zone 328 below the distributor grid plate 326, and the upper end 329 defining an approximate boundary between the expanded catalyst zone 322 and the upper catalyst-free zone 330. A dashed boundary line 331 schematically illustrates an approximate level when the heterogeneous catalyst 324 is not in an expanded or fluidized state. Dispersed metal sulfide catalyst particles 325 are dispersed throughout the hydrocarbon mass in the ebullating bed reactor 310, both in the expanded catalyst zone 322 and in the lower and upper heterogeneous catalyst free zones 228, 230.

[0115] The hydrocarbons and other materials in the ebullating bed reactor 310 are continuously recirculated through a recirculation channel 332 connected to an ebullating pump 334 located outside the reactor 310. The materials are withdrawn from the upper heterogeneous catalyst-free zone 330 through a funnel-shaped recirculation cup 336. The recirculation cup 336 is spiral-shaped, which helps to separate hydrogen bubbles from the recirculated materials passing downward through the recirculation channel 332 to prevent cavitation in the ebullating pump 334. The recirculated materials enter the lower heterogeneous catalyst-free zone 328 through the discharge bell cover 343, where it is mixed with the fresh heavy oil feedstock 314 and hydrogen 316. The mixture passes upward through the distributor grid plate 326 and enters the expanded catalyst zone 322. Fresh heterogeneous catalyst can be periodically introduced into the expanded catalyst zone 322 through the catalyst inlet pipe 336, and the used heterogeneous catalyst can be periodically withdrawn through the catalyst discharge pipe 340.

[0116] Figure 3A The H-Oil fluidized bed reactor 310 and Figure 2 The main difference between the LC Fining ebullated bed reactors 200 shown is the location of the ebullated pump. The ebullated pump 334 in the H-Oil reactor 310 is located outside the reaction chamber. The recirculated material is introduced through a recirculation port with a distributor cap 343 at the bottom of the ebullated bed reactor 310. The distributor cap 343 helps to evenly distribute the material through the lower catalyst-free zone 328.

[0117] The upgraded material 320 is taken out from the outlet 318 of the ebullated bed reactor 310 and introduced into a separator 342 (e.g., a hot separator, an interstage pressure difference separator, an atmospheric distillation column, or a vacuum distillation column). The separator 342 is configured to separate a volatile fraction (gas and distillate) 346 from a non-volatile fraction (or liquid) 348. The distillate and gas 346 are removed at one position (e.g., the top) of the separator 342, and a non-volatile fraction 348 containing liquid hydrocarbons and residual dispersed metal sulfide catalyst particles is removed from another position (e.g., the bottom) of the separator 342.

[0118] Figure 3B A hydroprocessing system 300 is schematically depicted, which includes a slurry phase reactor 302 and a separator 304 (e.g., a hot separator, an interstage pressure differential separator, or a distillation column). A heavy oil feedstock 306 is mixed and conditioned with a catalyst precursor mixture 308 using a mixing system 310 (i.e., a plurality of parallel mixing lines and bypass lines disclosed herein). The diluted precursor mixture 308 includes a catalyst mixed with a diluent formed in a premixer (not shown). The conditioned feedstock from the mixing system 310 is pressurized by a pump 312, which can also be used as a multi-stage mixing device to further disperse the catalyst precursor throughout the heavy feedstock 306, passes through a preheater 314, and is fed into the slurry phase reactor 302 along with hydrogen 316 through one or more input ports 318 located at or near the bottom of the slurry phase reactor 302.

[0119] The agitator 320 at the bottom of the slurry phase reactor 302 induces mixing in the liquid phase, thereby helping to more evenly disperse the heat generated by the hydrocracking reaction. Alternatively, or in addition to the agitator 320, the slurry phase reactor 302 may include a circulation channel, a circulation pump, and a distributor grid plate (not shown), as in a conventional ebullating bed reactor (see Figure 2 and 3A ) to promote a more uniform dispersion of reactants, catalysts, and heat. Hydrogen is schematically depicted as bubbles 322, and dispersed metal sulfide catalyst particles are schematically depicted as catalyst particles 324 in reactor 302. It should be understood that bubbles 322 and catalyst particles 324 are shown enlarged so that they can be seen in the figure. In fact, they may not be visible to the naked eye.

[0120] The heavy oil feedstock 306 is catalytically upgraded in the presence of hydrogen 316 and a dispersed metal sulfide catalyst 324 in the slurry phase reactor 302 to form an upgraded hydrocarbon product 326. The upgraded product 326 is continuously withdrawn from the slurry phase reactor 302 through an output port 328 located at or near the top of the reactor 302 and then fed to a separator 304 (e.g., a hot separator and / or a distillation column), optionally after passing through an optional hydroprocessing unit 330. The upgraded product 326 fed to the separator 304 contains residual catalyst particles, schematically depicted as particles 324', and residual hydrogen, schematically depicted as bubbles 322', which can continue to promote beneficial upgrading reactions and reduce equipment fouling. The separator 304 separates the volatile fraction 305 from the non-volatile fraction 307. The volatile fraction 305 is taken out from the top of the hot separator 304 , and the non-volatile fraction 307 is taken out from the bottom of the hot separator 304 .

[0121] Figure 3C A hydroprocessing system 300 is schematically depicted, which includes a slurry phase reactor 302, a hot separator 304, and a fixed bed reactor 360. The upgraded hydrocarbon material 326 contains residual dispersed metal sulfide catalyst particles, schematically depicted as particles 324' in the hot separator 304. The residual dispersed metal sulfide catalyst particles 324' in the liquid fraction 307 from the hot separator 304 are introduced into the fixed bed reactor 360 for further hydroprocessing. The fixed bed reactor 360 can be designed to perform hydrocracking and / or hydroprocessing reactions depending on the operating temperature and / or the type of solid supported catalyst used in the fixed bed reactor 360.

[0122] The fixed bed reactor 360 more specifically includes an input port 362 at the top (liquid fraction 307 and supplemental hydrogen 364 are introduced through the input port), and an output port 366 at the bottom (further hydroprocessed material 368 is discharged through the output port). The fixed bed reactor 360 also includes a plurality of vertically stacked and spaced catalyst beds 370, which include a filled porous supported catalyst. Above each catalyst bed 370 is a distributor grid 372, which helps to more evenly distribute the feedstock flow passing downward through the catalyst bed 370. An unloaded catalyst zone 374 exists above and below each catalyst bed 370. In the catalyst bed 370 and the unloaded catalyst zone 374, the residual catalyst particles 324' remain dispersed throughout the feedstock within the fixed bed reactor 360, which further promotes the beneficial quality improvement reaction. An auxiliary port 376 may be provided at the center and / or bottom of the fixed bed reactor 360, through which cooling oil and / or hydrogen quenching may be introduced to cool the heat generated by the hydroprocessing reaction and control the reaction rate, thereby helping to prevent the formation of coke precursors and deposits and / or excess gas within the fixed bed reactor 360.

[0123] Figure 4A Schematically illustrated is an ebullated bed hydroprocessing system 400 including a plurality of ebullated bed reactors 410. The hydroprocessing system 400 (an example of which is a LC-refining or H-Oil hydroprocessing unit) can include three ebullated bed reactors 410a, 410b, 410c in series for upgrading a feedstock 412. The feedstock 412 from a buffer tank 414 is pressurized, preheated, and introduced into a first ebullated bed reactor 410a together with hydrogen 416, and the feedstock 412 and hydrogen 416 are passed through respective heaters before entering the first reactor 410a. The upgraded hydrocarbon material 420a from the first ebullated bed reactor 410a is introduced into a second ebullated bed reactor 410b together with additional hydrogen 416. The upgraded hydrocarbon material 420b from the second ebullated bed reactor 410b is introduced into a third ebullated bed reactor 410c together with additional hydrogen 416.

[0124] It should be understood that one or more interstage separators (not shown) may be optionally inserted between the first and second ebullated bed reactors 410a, 410b and / or between the second and third ebullated bed reactors 410b, 410c to remove low boiling fractions and gases from the non-volatile fraction containing liquid hydrocarbons and residual dispersed metal sulfide catalyst particles. It may be desirable to remove lower alkanes, such as hexane and heptane, which are valuable fuel products but are poor solvents for asphaltenes. Removing volatile substances between multiple reactors increases the yield of upgraded products and increases the solubility of asphaltenes in liquid hydrocarbon materials fed to downstream reactors. Both improve the efficiency of the entire hydroprocessing system.

[0125] The upgraded hydrocarbon material 420c from the third ebullated bed reactor 410c is sent to a high temperature separator 442a, which separates volatile and non-volatile fractions. The volatile fraction 446a passes through a heat exchanger 450 (the heat removed by the heat exchanger 450 can be used to preheat the hydrogen 416) and is then fed to the first ebullated bed reactor 410a. The slightly cooled volatile fraction 446a is sent to a medium temperature separator 442b, which separates the remaining volatile fraction 446b formed by cooling the heat exchanger 450 from the resulting liquid fraction 448b. The remaining volatile fraction 446b is sent to a downstream low temperature separator 442c for further separation into a gas fraction 452c and a degassed liquid fraction 448c.

[0126] The liquid fraction 448a from the high temperature separator 442a is combined with the obtained liquid fraction 448b from the medium temperature separator 442b, and the mixture is sent to the low pressure separator 442d, which separates the degassed liquid fraction 448d from the hydrogen-rich gas 452d. The degassed liquid fraction 448d is sent together with the degassed liquid fraction 448c from the low temperature separator 442c to the back-end system 460, and the back-end system 460 includes one or more distillation columns, including a vacuum distillation column, in which the substances are fractionated into products.

[0127] The gaseous fraction 452c from the low temperature separator 442c is purified into waste gas, purge gas and hydrogen 416. The hydrogen 416 is compressed, mixed with supplementary hydrogen 416a, and either passed through a heat exchanger 450 and introduced into the first ebullated bed reactor 410a together with the feedstock 414, or directly introduced into the second and third ebullated bed reactors 410b, 410c.

[0128] Figure 4B A fluidized bed hydroprocessing system 400 including a plurality of ebullating bed reactors is schematically illustrated, which is similar to Figure 4A The system shown in the figure, but shows an interstage separator 421 between the second and third ebullated bed reactors 410b, 410c (although the interstage separator 421 (or other separator) can be between the first and second ebullated bed reactors 410a, 410b). As shown, the effluent from the second stage ebullated bed reactor 410b enters the interstage separator 421, which can be a high pressure, high temperature separator. The liquid fraction from the separator 421 is combined with a portion of the recycled hydrogen from the pipeline 416 and fed into the third stage reactor 410c. The vapor fraction from the interstage separator 421 bypasses the third stage reactor 410c, mixes with the effluent from the third stage reactor 410c, and then enters the high pressure and high temperature separator 442a.

[0129] This allows the lighter, more saturated components formed in the first two reactors 410a, 410b to bypass the third reactor 410c. This has the benefits of (1) reducing the vapor load on the third reactor 410c, which increases the volume utilization of the third reactor for converting the remaining heavy components, and (2) reducing the concentration of "anti-solvent" components (saturates) that can destabilize (e.g., precipitate) the asphaltenes in the third reactor 410c.

[0130] Hydroprocessing systems are typically configured and operated to promote more vigorous hydrocracking reactions rather than less vigorous hydrotreating reactions such as hydrotreating. 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, primarily involves the hydrogenation of unsaturated hydrocarbons with little or no breaking of carbon-carbon molecular bonds.

[0131] In order to promote more vigorous hydrocracking reactions rather than less vigorous hydrotreating reactions, the hydrotreating reactor is 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 at a pressure in the range of about 1000 psig (6.9 MPa) to about 3000 psig (20.7 MPa), more preferably in the range of about 1500 psig (10.3 MPa) to about 2500 psig (17.2 MPa), and preferably at a rate of about 0.05 hr. -1 To about 0.45hr -1 , more preferably about 0.1 hr -1 To about 0.35hr -1 The difference between hydrocracking and hydrotreating can be expressed in terms of resid conversion (hydrocracking results in a large conversion of higher boiling hydrocarbons to lower boiling hydrocarbons, while hydrotreating does not).

[0132] The hydroprocessing system disclosed herein can result in a total resid conversion in the range of about 60% to about 95%, preferably in the range of about 75% to about 90%. Due to the differences in processing difficulty between different feedstocks, the preferred conversion range generally depends on the type of feedstock.

[0133] Compared to operating an ebullated bed reactor with a heterogeneous catalyst alone, operating an ebullated bed reactor with a dual catalyst system can result in the same or reduced equipment fouling. For example, when a dual catalyst system is used instead of a heterogeneous catalyst by itself, the rate of equipment fouling can result in one or more of the following benefits: (i) reducing the frequency of heat exchanger shutdowns and / or distillation column shutdowns for cleaning; (ii) reducing the frequency of filter and strainer replacement or cleaning; (iii) reducing the frequency of switching to a backup heat exchanger; (iv) reducing the surface temperature of equipment such as a heat exchanger, separator, or distillation column; (v) reducing the rate of increase in furnace tube metal temperature; and (vi) reducing the rate of increase in the calculated fouling thermal resistance coefficient of a heat exchanger.

[0134] IV. Hybrid Systems and Methods

[0135] Figures 5A-7B An example blending system and corresponding method for producing a well-mixed conditioned heavy oil feedstock is illustrated. Figure 5A-5B An example mixing system 500 is shown having two parallel mixing lines. Figure 6A-6B An example mixing system 600 is shown having three parallel mixing lines. Figure 7A-7B An example mixing system 700 is shown having four parallel mixing lines. It should be understood that Figures 5A-7B Only mixing systems within the meaning and scope of the present disclosure are illustrated. The mixing system may be modified as desired without departing from the spirit of the present invention, such as including additional mixing lines and / or other processing equipment.

[0136] Figure 5A-5B More specifically illustrated is a mixing system 500 configured to mix a heavy oil feedstock 502 with a diluted precursor mixture 508. The diluted precursor mixture 508 is formed by mixing a catalyst precursor 504 (e.g., an oil-soluble catalyst precursor) with a diluent 506 using one or more mixers known in the art, such as one or more inline static mixers and / or one or more high shear mixers. The heavy oil feedstock 502 and the diluted precursor mixture 508 are fed into a common feed line 510 that is divided into first and second parallel mixing lines 512a, 512b.

[0137] The heavy oil feedstock side stream 536 may optionally be used as a diluent to prepare the diluted precursor mixture 508. A cooler 538 may be used to reduce the temperature of the heavy oil feedstock side stream 536 to prevent premature thermal decomposition of the catalyst precursor 504 in the diluted precursor mixture 508 before it is thoroughly mixed with the heavy oil feedstock 502.

[0138] Each mixing line 512a, 512b can include an upstream valve 514a, 514b that can be selectively opened during operation of the mixing line 512a, 512b, and closed to take the mixing line 512 offline for maintenance and cleaning. When online, the upstream valves 514a, 514b are opened to allow the split streams of the heavy oil feedstock 502 and the diluted precursor mixture 508 to flow through the first and second mixing lines 512a, 512b. In a preferred embodiment, the first and second parallel mixing lines are designed with symmetrical piping and mixing equipment so that the pressure drop through each parallel mixing line 512 is substantially equal, and equal flow rates between the different mixing lines 512 can be maintained. However, mixing lines 512 of different capacities and flow rates can be used, such as when a single-train mixing line is modified to include one or more additional mixing lines.

[0139] exist Figure 5AIn the illustrated mixing system 500, the split streams of the heavy oil feedstock 502 and the diluted precursor mixture 508 are initially mixed by first and second static inline mixers 516a, 516b to produce first and second initially mixed streams, which are then passed through first and second strainers 518a, 518b to remove any unwanted solids from the initially mixed streams. The first and second mixed streams are then fed into first and second high shear mixers 520a, 520b, which provide first and second conditioned feedstock streams. Optional first and second flow meters 522a, 522b may be provided to measure the flow through the first and second mixing lines 512a, 512b downstream of the first and second high shear mixers 520a, 520b.

[0140] Figure 5B Similar to Figure 5A , except that a common static inline mixer 516 is located on the common feed line 510 and acts as a premixer upstream of the bifurcation of the first and second parallel mixing lines 512a and 512b, and the individual static inline mixers 516a, 516b in the mixing lines 512a and 512b are omitted.

[0141] The first and second flow control devices 524a, 524b are located downstream of the high shear mixers 520a, 520b, respectively. The flow control devices 524a, 524b can provide multiple functions. When the first and second parallel mixing lines 512a, 512b are both online, the flow control devices 524a, 524b will be opened. When one of the mixing lines 512 is offline, the corresponding flow control device 524 can be closed to prevent the pressurized conditioned feedstock from flowing back from the other mixing line 512 that is still in operation. The flow control device 524 of the mixing line 512 that is still in operation can be opened all the time, or can be partially closed to restrict the flow and increase the upstream pressure, thereby causing or causing a portion of the heavy oil feedstock 502 to enter the bypass line 540.

[0142] The conditioned feedstock streams from the first and second mixing lines 512a, 512b are fed into the common discharge line 525 and combined therein to form a common conditioned feedstock stream 546. The common conditioned feedstock stream 546 passes through or through a common flow measurement device 528 (e.g., a flow meter), then through a common flow control device 526 (e.g., a valve), recombines with any heavy oil feedstock from the bypass line 540, and then enters the buffer tank 530.

[0143] The conditioned feedstock side stream 532 from the buffer tank 530 may optionally be used as a diluent to prepare the diluted precursor mixture 508. A cooler 534 may be used to reduce the temperature of the conditioned feedstock side stream 532 to prevent premature thermal decomposition of the catalyst precursor 504 in the diluted precursor mixture 508 before it is thoroughly mixed with the heavy oil feedstock 502.

[0144] When both parallel mixing lines 512a, 512b are online and operational, the common flow control device 526 is open. When one of the mixing lines 512a, 512b is closed and offline, the common flow control device 526 can be partially closed to restrict the flow of material through the common discharge line 525 and increase the upstream pressure to cause or allow a portion of the heavy oil feedstock to enter the bypass line 540. The common flow control device 526 can be used alone or in combination with one of the flow control devices 524 corresponding to the mixing line 512 that is still in operation.

[0145] When both the first and second mixing lines 512a, 512b are online and operating, the bypass line 540 is generally free of the heavy oil feedstock 502. However, when one of the parallel mixing lines 512 is shut down and taken offline, the portion of the heavy oil feedstock 502 that is not fed into the remaining online mixing line 512 is caused or allowed to pass through the bypass line 540 to maintain the production of the heavy oil feedstock 502 through the mixing system 500. As described above, the flow of the heavy oil feedstock 502 through the bypass line 540 is caused or caused by partially closing the common flow control valve 526 and / or the mixing line valve 524 of the operating mixing line 512 to restrict the flow through the common discharge line 525. This causes a pressure drop and increases the upstream pressure sufficiently to allow a portion of the heavy oil feedstock 502 to enter the bypass line 540. An optional flow meter 542 on the bypass line 540 measures the flow of the heavy oil feedstock 502 flowing through the bypass line 540. The bypass line 540 is connected to the common discharge line 525 to combine the heavy oil feedstock 508 from the bypass line with a common conditioned feedstock stream 546 downstream of the flow control device 526 and the flow meter 528 .

[0146] The flow rates of the diverted heavy oil feedstock streams through the remaining operational mixing line 512 and the bypass line 540, respectively, can be measured by the common flow meter 528 and the optional bypass flow meter 542, respectively. By adjusting the common flow control valve 526 and / or the bypass line valve 544, the respective flow rates of the materials through the remaining operational mixing line 512 and the bypass line 540 can be adjusted. By measuring the flow rates using flow meters and making adjustments using flow control devices, a desired balance of flow rates through the various lines can be achieved and maintained. In addition to regulating the flow through the bypass line 540, when the first and second mixing lines 512a, 512b are open and operational, the bypass line valve 544 can be closed or partially restricted to balance the line pressures to ensure that the heavy oil feedstock 502 does not flow forward or backward through the bypass line 540.

[0147] Example methods of mixing the catalyst precursor into the heavy oil include using Figure 5A The hybrid system 500 shown includes:

[0148] (1) mixing a certain amount of catalyst precursor 504 with a certain amount of diluent 506 to form a diluted precursor mixture 508;

[0149] (2) mixing the diluted precursor mixture 508 with the heavy oil feedstock 502 using a plurality of parallel mixing lines 512 to form a plurality of conditioned feedstock streams, each parallel mixing line 512 comprising one or more mixers 516, 520 and at least one valve 514, 524 for regulating flow in the mixing line 512;

[0151] (3) combining the conditioned feed streams in a common discharge line 525 downstream of the parallel mixing line 512 to form a common conditioned feed stream 546;

[0152] (4) stopping flow through mixing line 512 and directing or allowing a portion of heavy oil feedstock 502 to bypass line 540, bypass parallel mixing line 512, and combine with common conditioned feedstock stream 546 in common discharge line 525; and

[0153] (5) While a portion of the heavy oil feedstock 502 passes through the bypass line 540 , at least one other parallel mixing line 512 is used to continue mixing at least a portion of the diluted precursor mixture 508 with the remaining portion of the heavy oil feedstock 502 .

[0154] When using Figure 5B As shown in the alternative mixing system 500, the method alternatively includes the step of premixing the diluted precursor mixture 508 with the heavy oil feedstock 502 using a common static inline mixer 516 upstream of the bifurcation of the first and second mixing lines 512a, 512b. The method also omits the use of Figure 5A Static inline mixers 516a , 516b on first and second mixing lines 512a , 512b are shown mixing the diluted precursor mixture 508 with the heavy oil feedstock 502 .

[0155] By way of illustration and not limitation, a typical hydroprocessing system may require a heavy oil flow rate of 100 to 300 tons / hour. When operating both the first and second parallel mixing lines 512a, 512b, it may be advantageous or preferred to evenly distribute the heavy oil feedstock 502 so that there is a symmetrical (e.g., equal) flow of material through each of the first and second parallel mixing lines 512a, 512b (e.g., 50 tons per hour through each mixing line 512a, 512b for a mixing system designed to process 100 tons per hour).

[0156] When one of the blending lines 512 is closed and taken offline, a portion of the heavy oil feedstock is rerouted through the bypass line 540 to maintain the same or similar flow rate (approximately 100 to 300 tons / hour) of the heavy oil feedstock 502 through the blending system 500. By way of example and not limitation, for a blending system 500 designed for a total flow rate of 100 tons / hour, the flow rate of the heavy oil feedstock 502 through the bypass line 540 and the remaining online blending line 512 may be the same, i.e., approximately 50 tons / hour through each line. In a preferred embodiment, the flow rate of the heavy oil feedstock 502 through the remaining online blending line 512 is increased to above 50 tons / hour, and the flow rate of the heavy oil feedstock 502 through the bypass line 540 is reduced to below 50 tons / hour.

[0157] For example, the flow rate through the remaining online mixing line 512 can be increased by at least about 55 tons / hour, at least about 60 tons / hour, at least about 65 tons / hour, or at least about 70 tons / hour, such as up to about 75 tons / hour, which is consistent with the capacity limitations of the mixing line and the mixer. In order to maintain the same or similar flow rate of heavy oil feedstock through the system (100 tons / hour), the corresponding flow rate through the bypass line can be about 45 tons / hour or less, or about 40 tons / hour or less, or about 35 tons / hour or less, or about 30 tons / hour or less, such as about 25 tons / hour.

[0158] Alternatively, the flow rate of the heavy oil feedstock 502 through the bypass line 540 may be greater than the flow rate through the remaining online mixing line 512. For example, the flow rate through the bypass line 540 may be at least about 55 tons / hour, at least about 60 tons / hour, at least about 65 tons / hour, or at least about 70 tons / hour, such as up to about 75 tons / hour. In order to maintain the same or similar flow rate of the heavy oil feedstock through the system (100 tons / hour), the corresponding flow rate through the remaining online mixing line 512 may be reduced to about 45 tons / hour or less, or about 40 tons / hour or less, or about 35 tons / hour or less, or about 30 tons / hour or less, such as about 25 tons / hour.

[0159] It should be understood that the mixing system 500 can be scaled up or down depending on the size of the hydroprocessing reactor being fed, and the flow rate is less than or greater than 100 tons / hour. In this case, a percentage of the nominal capacity can be used to describe the flow rate. If 100% represents the nominal flow rate of the heavy oil feedstock 502 through the mixing system 500, during normal operation of the parallel mixing lines 512a, 512b, the amount of heavy oil feedstock 502 passing through each mixing line 512 can be about 50% of the total flow rate. When one of the mixing lines 512 is closed and offline, about 50% of the total flow rate can be transferred to the bypass line 540, while about 50% of the total flow rate continues to pass through the remaining online mixing lines 512.

[0160] In preferred embodiments, and consistent with the capacity limitations of the mixing lines and mixers, the flow rate through the remaining in-line mixing line 512 can be increased to at least about 55% of the total flow rate through the mixing system 500, at least about 60% of the total flow rate, at least about 65% of the total flow rate, or at least about 70% of the total flow rate, such as up to about 75% of the total flow rate. To maintain the same or similar flow rate of the heavy oil feedstock through the mixing system 500, the corresponding flow rate through the bypass line can be about 45% or less of the total flow rate through the mixing system 500, or about 40% or less of the total flow rate, or about 35% or less of the total flow rate, or about 30% or less of the total flow rate, such as about 25% of the total flow rate.

[0161] Alternatively, the flow rate of the heavy oil feedstock 502 through the bypass line 540 can be greater than the flow rate through the remaining online mixing line 512. For example, the flow rate through the bypass line 540 can be at least about 55% of the total flow rate through the mixing system 500, at least about 60% of the total flow rate, at least about 65% of the total flow rate, or at least about 70% of the total flow rate, such as up to about 75% of the total flow rate. In order to maintain the same or similar flow rate of the heavy oil feedstock through the mixing system 500, the corresponding flow rate through the remaining online mixing line 512 can be reduced to about 45% or less of the total flow rate through the mixing system 500, or about 40% or less of the total flow rate, or about 35% or less of the total flow rate, or about 30% or less of the total flow rate, such as about 25% of the total flow rate.

[0162] In view of the foregoing, each parallel mixing line 512a, 512b can have a capacity to operate at a flow rate of about 0-55 tons / hour, or about 0-60 tons / hour, or about 0-65 tons / hour, or about 0-70 tons / hour, or about 0-75 tons / hour. The bypass line 540 can be configured to have a flow capacity of about 0-50 tons / hour, or about 0-55 tons / hour, or about 0-60 tons / hour, or about 0-70 tons / hour, or about 0-75 tons / hour.

[0163] In the case where the heavy oil feedstock side stream 536 is used as a diluent to prepare the diluted precursor mixture 508, and the flow rate of the heavy oil feedstock 502 through the mixing system 500 is about 100 tons / hour, the amount of the heavy oil feedstock side stream 536 can be up to about 10 tons / hour, or up to about 5 tons / hour (or between about 0-10 tons / hour, or about 0-5 tons / hour, depending on the conditions within the mixing system 500). In the case where the flow rate of the heavy oil feedstock 502 through the mixing system 500 is less than or greater than 100 tons / hour, the flow rate of the heavy oil feedstock side stream 536 used as a diluent to prepare the diluted precursor mixture 508 can be up to about 10%, or about 5% of the total flow rate (or between about 0-10%, or about 5% of the total flow rate, depending on the conditions within the mixing system 500).

[0164] In the case where the conditioned heavy oil feedstock side stream 532 is used as a diluent to prepare the diluted precursor mixture 508, and the flow rate of the heavy oil feedstock 502 through the mixing system 500 is about 100 tons / hour, the amount of the conditioned heavy oil feedstock side stream 532 can be up to about 10 tons / hour, or up to about 5 tons / hour (or between about 0-10 tons / hour, or about 0-5 tons / hour, depending on the conditions within the mixing system 500). In the case where the flow rate of the heavy oil feedstock 502 through the mixing system 500 is less than or greater than 100 tons / hour, the flow rate of the conditioned heavy oil feedstock side stream 532 used as a diluent to prepare the diluted precursor mixture 508 can be up to about 10% of the total flow rate, or about 5% of the total flow rate (or between about 0-10% of the total flow rate, or about 5%, depending on the conditions within the mixing system 500).

[0165] Figure 6A-6B The diagram is similar to Figure 5A-5B The mixing system 500 in the embodiment of the present invention but includes a mixing system 600 of three parallel mixing lines 612. The heavy oil feedstock 602 and the diluted precursor mixture 608 are fed into a common feed line 610, which is divided into first, second and third parallel mixing lines 612a, 612b, 612c. By way of example and not limitation, the mixing system 600 can be configured to allow a total flow rate of heavy oil through the system of greater than 100 tons / hour, such as 150 to 350 tons / hour, to accommodate larger hydroprocessing reactors and greater capacity of the system.

[0166] Each mixing line 612a, 612b, 612c can include an upstream valve 614a, 614b, 614c, which can be selectively opened during operation of the mixing line 612a, 612b, 612c, and closed to take the mixing line 612 offline for maintenance and cleaning. When online, the upstream valve 614a, 614b, 614c is opened to allow the split streams of the heavy oil feedstock 602 and the diluted precursor mixture 608 to flow through the first, second and third mixing lines 612a, 612b, 612c. In a preferred embodiment, the parallel mixing lines 612 are designed with symmetrical piping and mixing equipment so that the pressure drop through each parallel mixing line 612 is substantially equal, and equal flow rates between different mixing lines 612 can be maintained. However, mixing lines 612 of different capacities and flows can be used, such as when a single-line mixing line or a dual-line mixing line is modified to include one or more additional mixing lines.

[0167] exist Fig. 6AIn the mixing system 600 shown, the split streams of the heavy oil feedstock 602 and the diluted precursor mixture 608 in the mixing pipelines 612a, 612b, 612c are initially mixed by static inline mixers 616a, 616b, 616c, respectively, to produce the first, second and third initially mixed streams, and then pass through corresponding coarse filters 618a, 618b, 618c to remove any unwanted solids in the initially mixed streams. The mixed streams are then fed to the first, second and third high shear mixers 620a, 620b, 620c, respectively, which provide the first, second and third conditioned feedstock streams. Optional first, second and third flow meters 622a, 622b, 622c can be provided to measure the flow rate of each of the three mixing pipelines 612 downstream of the high shear mixer 620.

[0168] Figure 6B Similar to Fig. 6A , except that a common static inline mixer 616 is located on the common feed line 610 and acts as a premixer upstream of the bifurcation of the first, second and third parallel mixing lines 612a, 612b and 612c, and the individual static inline mixers 616a, 616b, 616c in the mixing lines 612a, 612b and 612c are omitted.

[0169] Flow control devices 624a, 624b, 624c are located downstream of each of the high shear mixers 620a, 620b, 620c, respectively. The flow control device 624 can provide multiple functions. When the first, second and third parallel mixing pipelines 612a, 612b, 612c are all online, the flow control devices 624a, 624b, 624c will be opened. When one of the mixing pipelines 612 is offline, the corresponding flow control device 624 can be closed to prevent the pressurized conditioned feedstock from flowing back from the other mixing pipeline 612 that is still in operation. The flow control device 624 of the mixing pipeline 612 that is still in operation can be opened all the time, or it can be partially closed to restrict the flow and increase the upstream pressure, thereby enabling or allowing a portion of the heavy oil feedstock to enter the bypass pipeline 640.

[0170] The conditioned feedstock streams from the first, second and third mixing lines 612a, 612b, 612c are fed into a common discharge line 625 and combined therein to form a common conditioned feedstock stream 646. The common conditioned feedstock stream 646 passes through or through a common flow measurement device 628 (e.g., a flow meter), then through a common flow control device 626 (e.g., a valve), recombines with any heavy oil feedstock from the bypass line 640, and then enters the buffer tank 630.

[0171] When the parallel mixing lines 612a, 612b, 612c are all online and operational, the flow control device 626 is open. When one of the mixing lines 612a, 612b, 612c is closed and offline, the common flow control device 626 can be partially closed to restrict the flow of material through the common discharge line 625 and increase the upstream pressure to allow or allow a portion of the heavy oil feedstock to enter the bypass line 640. The common flow control device 626 can be used alone or in combination with one or two flow control devices 624 corresponding to the mixing line 612 that is still in operation.

[0172] When the mixing lines 612a, 612b, 612c are all online and operating, the bypass line 640 is generally free of heavy oil feedstock 602. However, when one of the parallel mixing lines 612 is shut down and taken offline, the portion of the heavy oil feedstock 602 that is not fed into the remaining online mixing line 612 is caused or allowed to pass through the bypass line 640 to maintain the production of heavy oil feedstock 602 through the mixing system 600. As described above, the flow of heavy oil feedstock 602 through the bypass line 640 is caused or caused by partially closing the common flow control valve 626 and / or the mixing line valve 624 of the operating mixing line 612 to restrict the flow through the common discharge line 625. This causes a pressure drop and increases the upstream pressure enough to allow a portion of the heavy oil feedstock 602 to enter the bypass line 640. An optional flow meter 642 on the bypass line 640 measures the flow of heavy oil feedstock 602 flowing through the bypass line 640. The bypass line 640 is connected to the common discharge line 625 to combine the heavy oil feedstock 608 from the bypass line with a common conditioned feedstock stream 646 downstream of the flow control device 626 and the flow meter 628 .

[0173] The flow rates of the diverted heavy oil feedstock streams through the remaining operational mixing lines 612, the common discharge line 625, and the bypass line 640, respectively, can be measured by the corresponding mixing line flowmeter 622, the common flowmeter 628, and the optional bypass flowmeter 642, respectively. By adjusting the common flow control valve 626, the mixing line valve 624, and / or the bypass line valve 644, the respective flow rates of the materials through the remaining operational mixing lines 612 and the bypass line 640 can be adjusted. By measuring the flow rates using flow meters and making adjustments using flow control devices, the desired balance of the flow rates through the various lines can be achieved and maintained. In addition to adjusting the flow through the bypass line 640, when the three mixing lines 612 are open and operational, the bypass line valve 644 can be closed or partially restricted to balance the line pressure to ensure that the heavy oil feedstock 602 does not pass forward or backward through the bypass line 640.

[0174] Example methods of mixing the catalyst precursor into the heavy oil include using Fig. 6A The hybrid system 600 shown includes:

[0175] (1) mixing a certain amount of catalyst precursor 604 with a certain amount of diluent 606 to form a diluted precursor mixture 608;

[0176] (2) mixing the diluted precursor mixture 608 with the heavy oil feedstock 602 using three parallel mixing lines 612a, 612b, 612c to form three conditioned feedstock streams, each parallel mixing line 612 comprising one or more mixers 616, 620 and at least one valve 614, 624 for regulating flow in the mixing line 612;

[0177] (3) combining the conditioned feed streams in a common discharge line 625 downstream of the three parallel mixing lines 612 to form a common conditioned feed stream 646;

[0178] (4) stopping flow through one of the mixing lines 612 and directing or allowing a portion of the heavy oil feedstock 602 to enter a bypass line 640, bypassing the parallel mixing lines 612, and merging with a common conditioned feedstock stream 646 in a common discharge line 625; and

[0179] (5) While a portion of the heavy oil feedstock 602 passes through the bypass line 640 , the other two parallel mixing lines 612 continue to mix at least a portion of the diluted precursor mixture 608 with the remaining portion of the heavy oil feedstock 602 .

[0180] When using Figure 6B In the alternative mixing system 600 shown, the method alternatively includes the step of premixing the diluted precursor mixture 608 with the heavy oil feedstock 602 using a common static inline mixer 616 upstream of the bifurcation of the first, second and third mixing lines 612a, 612b, 612c. The method also omits the use of Fig. 6A Static inline mixers 616a , 616b , 616c on mixing lines 612a , 612b , 616c are shown mixing the diluted precursor mixture 608 with the heavy oil feedstock 602 .

[0181] By way of illustration and not limitation, a large hydroprocessing system may require a heavy oil flow rate of 150 to 350 tons / hour. When operating the first, second, and third parallel mixing lines 612a, 612b, 612c, it may be advantageous or preferred to evenly distribute the heavy oil feedstock 602 so that the material flow through each of the parallel mixing lines 612a, 612b, 612c is symmetrical (e.g., equal) (e.g., 50 tons / hour through each mixing line 612 for a mixing system designed to process 150 tons / hour).

[0182] When one of the three mixing lines 612 is closed and taken offline, a portion of the heavy oil feedstock is redirected through the bypass line 640 to maintain the same or similar flow rate (approximately 150 to 350 tons / hour) of the heavy oil feedstock 602 through the mixing system 600. By way of example and not limitation, for a mixing system 600 designed for a total flow rate of 150 tons / hour, the flow rate of the heavy oil feedstock 602 through the bypass line 640 and each of the remaining online mixing lines 612 can be the same, i.e., approximately 50 tons / hour through each line. In a preferred embodiment, the flow rate of the heavy oil feedstock 602 through each of the remaining online mixing lines 612 is increased to more than 50 tons / hour, and the flow rate of the heavy oil feedstock 602 through the bypass line 640 is reduced to less than 50 tons / hour.

[0183] For example, the flow rate through one or both of the remaining online mixing lines 612 can be increased by at least about 53 tons / hour, at least about 56 tons / hour, at least about 59 tons / hour, or at least about 62 tons / hour, such as up to about 65 tons / hour, consistent with the capacity limitations of the mixing lines and mixers. To maintain the same or similar flow rate of the heavy oil feedstock through the system (150 tons / hour), the corresponding flow rate through the bypass line can be about 44 tons / hour or less, or about 38 tons / hour or less, or about 32 tons / hour or less, or about 26 tons / hour or less, such as about 20 tons / hour.

[0184] Alternatively, the flow rate of the heavy oil feedstock 602 through the bypass line 640 can be greater than the flow rate through the remaining online mixing line 612. For example, the flow rate through the bypass line 640 can be at least about 55 tons / hour, at least about 60 tons / hour, at least about 65 tons / hour, or at least about 70 tons / hour, such as up to about 75 tons / hour. In order to maintain the same or similar flow rate of the heavy oil feedstock through the system (150 tons / hour), the combined flow rate through one or both remaining online mixing lines 612 can be reduced to about 95 tons / hour or less, or about 90 tons / hour or less, or about 85 tons / hour or less, or about 80 tons / hour or less, such as about 75 tons / hour.

[0185] It should be understood that the mixing system 600 can be scaled up or down depending on the size of the hydroprocessing reactor being fed, and the flow rate is less than or greater than 150 tons / hour. In this case, a percentage of the nominal capacity can be used to describe the flow rate. If 100% represents the nominal flow rate of the heavy oil feedstock 602 through the mixing system 600, during normal operation of the three parallel mixing lines 612a, 612b, 612c, the amount of heavy oil feedstock 602 passing through each mixing line 612 can be about 33% of the total flow rate. When one of the mixing lines 612 is closed and offline, about 33% of the total flow rate can be divided into the bypass line 640, while about 67% of the total flow rate continues to pass through the remaining online mixing lines 612.

[0186] In preferred embodiments, and consistent with the capacity limitations of the mixing lines and mixers, the combined flow through the remaining in-line mixing lines 612 can be increased to at least about 70% of the total flow, at least about 75% of the total flow, at least about 80% of the total flow, or at least about 85% of the total flow, such as up to about 90% of the total flow. To maintain the same or similar flow rate of the heavy oil feedstock through the system, the corresponding flow through the bypass line can be about 30% of the total flow or less, or about 25% of the total flow or less, or about 20% of the total flow or less, or about 15% of the total flow or less, such as about 10% of the total flow.

[0187] Alternatively, the flow rate of the heavy oil feedstock 602 through the bypass line 640 can be greater than the flow rate through each of the remaining in-line mixing lines 612. For example, the flow rate through the bypass line 640 can be at least about 35% of the total flow rate through the mixing system 600, at least about 40% of the total flow rate, at least about 45% of the total flow rate, or at least about 50% of the total flow rate, such as up to about 55% of the total flow rate. In order to maintain the same or similar flow rate of the heavy oil feedstock through the mixing system 600, the combined flow rate through the remaining in-line mixing lines 612 can be reduced to about 65% or less of the total flow rate through the mixing system 600, or about 60% or less of the total flow rate, or about 55% or less of the total flow rate, or about 50% or less of the total flow rate, such as about 45% of the total flow rate.

[0188] In view of the foregoing, each parallel mixing line 612a, 612b, 612c can have a capacity to operate at a flow rate of about 0-53 tons / hour, or about 0-56 tons / hour, or about 0-59 tons / hour, or about 0-62 tons / hour, or about 0-65 tons / hour. The bypass line 640 can be configured to have a flow capacity of about 0-50 tons / hour, or about 0-55 tons / hour, or about 0-60 tons / hour, or about 0-65 tons / hour, or about 0-70 tons / hour, or about 0-75 tons / hour, or about 0-80 tons / hour, or about 0-90 tons / hour, or about 0-100 tons / hour. Therefore, Figure 6A-6B It is shown how the capacity of the mixing system 600 may be increased by approximately 50% or more without increasing the capacity of each mixing line 612. However, it should be understood that the mixing lines 612 may have a smaller or larger capacity as desired.

[0189] Figure 7A-7B The diagram is similar to Figure 5A-5B The mixing system 700 is similar to the mixing system 500 in FIG. 5 but includes four parallel mixing lines 712. The heavy oil feedstock 702 and the diluted precursor mixture 708 are fed into a common feed line 710, which is divided into four parallel mixing lines 712a, 712b, 712c, 712d. By way of example and not limitation, the mixing system 700 can be configured to allow a total flow rate of heavy oil through the system of greater than 150 tons / hour, such as 200 to 400 tons / hour, to accommodate even larger hydroprocessing reactors and even larger capacities of the system.

[0190] Each mixing line 712a, 712b, 712c, 712d can include an upstream valve 714a, 714b, 714c, 714d, which can be selectively opened during operation of the mixing line 712a, 712b, 712c, 712d, and closed to take the mixing line 712 offline for maintenance and cleaning. When online, the upstream valve 714a, 714b, 714c, 714df is opened to allow the split streams of the heavy oil feedstock 702 and the diluted precursor mixture 708 to flow through the first, second, third, and fourth mixing lines 712a, 712b, 712c, 714d. In a preferred embodiment, the parallel mixing lines 712 are designed with symmetrical piping and mixing equipment so that the pressure drop through each parallel mixing line 712 is substantially equal, and equal flow between different mixing lines 712 can be maintained. However, mixing lines 712 of different capacities and flows may be used, such as when a single-train mixing line, a dual-train mixing line, or a triple-train mixing line is modified to include one or more additional mixing lines.

[0191] exist Fig. 7AIn the mixing system 700 shown, the split streams of the heavy oil feedstock 702 and the diluted precursor mixture 708 are initially mixed by static inline mixers 716a, 716b, 716c, 716d, respectively, to produce the first, second, third and fourth initially mixed streams, and then any unwanted solids in the initially mixed streams are removed by corresponding coarse filters 718a, 718b, 718c, 718d. The mixed streams are then fed to the first, second, third and fourth high shear mixers 720a, 720b, 720c, 720d, respectively, which provide the first, second, third and fourth conditioned feedstock streams. Optional first, second, third and fourth flow meters 722a, 722b, 722c, 722d can be provided to measure the flow rate of each of the four mixing lines 712 downstream of the high shear mixer 720.

[0192] Figure 7B Similar to Fig. 7A , except that a common static inline mixer 716 is located on the common feed line 710 and acts as a premixer upstream of the bifurcation of the first, second, third and fourth parallel mixing lines 712a, 712b, 712c and 712d, and the individual static inline mixers 716a, 716b, 716c, 716d in the mixing lines 712a, 712b, 712c and 712d are omitted.

[0193] Flow control devices 724a, 724b, 724c, 742d are located downstream of each of the high shear mixers 720a, 720b, 720b, 720d, respectively. Flow control device 724 can provide multiple functions. When the first, second, third and fourth parallel mixing pipelines 712a, 712b, 712c, 714d are all online, flow control devices 724a, 724b, 724c, 724d will be opened. When one or two of the mixing pipelines 712 are offline, the corresponding flow control device 724 can be closed to prevent the pressurized conditioned raw material from flowing back from the other mixing pipelines 712 that are still in operation. The flow control device 724 of the mixing pipeline 712 that is still in operation can be opened all the time, or it can be partially closed to limit the flow and increase the upstream pressure, thereby enabling or allowing a portion of the heavy oil raw material to enter the bypass pipeline 740.

[0194] The conditioned feedstock streams from the first, second, third and fourth mixing lines 712a, 712b, 712c, 712d are fed into a common discharge line 725 and combined therein to form a common conditioned feedstock stream 746. The common conditioned feedstock stream 746 passes through or through a common flow measurement device 728 (e.g., a flow meter), then through a common flow control device 726 (e.g., a valve), recombines with any heavy oil feedstock from the bypass line 740, and then enters the buffer tank 730.

[0195] When the parallel mixing lines 712a, 712b, 712c, 712d are all online and operating, the flow control device 726 is open. When one or two of the mixing lines 712a, 712b, 712c, 712d are closed and offline, the common flow control device 726 can be partially closed to restrict the flow of materials through the common discharge line 725 and create a pressure drop to allow or allow a portion of the heavy oil feedstock to enter the bypass line 740. The common flow control device 726 can be used alone or in combination with one or two flow control devices 724 corresponding to the mixing lines 712 that are still in operation.

[0196] When the mixing lines 712a, 712b, 712c, 712d are all online and operating, the bypass line 740 is generally free of heavy oil feedstock 702. However, when one or two of the parallel mixing lines 712 are closed and offline, the portion of the heavy oil feedstock 702 that is not fed into the remaining online mixing lines 712 is made or allowed to pass through the bypass line 740 to maintain the production of heavy oil feedstock 702 through the mixing system 700. As described above, the flow of heavy oil feedstock 702 through the bypass line 740 is caused or caused by partially closing the common flow control valve 726 and / or the mixing line valve 724 of the operating mixing line 712 to restrict the flow through the common discharge line 725. This causes a pressure drop and increases the upstream pressure enough to allow a portion of the heavy oil feedstock 702 to enter the bypass line 740. The optional flow meter 742 on the bypass line 740 measures the flow of heavy oil feedstock 702 flowing through the bypass line 740. The bypass line 740 is connected to the common discharge line 725 to combine the heavy oil feedstock 708 from the bypass line with a common conditioned feedstock stream 746 downstream of the flow control device 726 and the flow meter 728 .

[0197] The flow rates of the diverted heavy oil feedstock streams through the remaining operational mixing lines 712, the common discharge line 725, and the bypass line 740, respectively, can be measured by the corresponding mixing line flowmeter 722, the common flowmeter 728, and the optional bypass flowmeter 742, respectively. By adjusting the common flow control valve 726, the mixing line valve 724, and / or the bypass line valve 744, the respective flow rates of the materials through the remaining operational mixing lines 712 and the bypass line 740 can be adjusted. By measuring the flow rates using flowmeters and making adjustments using flow control devices, the desired balance of the flow rates through the various lines can be achieved and maintained. In addition to adjusting the flow through the bypass line 740, when the four mixing lines 712 are open and operational, the bypass line valve 744 can be closed or partially restricted to balance the line pressure to ensure that the heavy oil feedstock 702 does not pass forward or backward through the bypass line 740.

[0198] Example methods of mixing the catalyst precursor into the heavy oil include using Fig. 7A The hybrid system 700 shown includes:

[0199] (1) mixing a certain amount of catalyst precursor 704 with a certain amount of diluent 706 to form a diluted precursor mixture 708;

[0200] (2) mixing the diluted precursor mixture 708 with the heavy oil feedstock 702 using four parallel mixing lines 712a, 712b, 712c, 714d to form four conditioned feedstock streams, each parallel mixing line 712 comprising one or more mixers 716, 720 and at least one valve 714, 724 for regulating flow in the mixing line 712;

[0201] (3) combining the conditioned feed streams in a common discharge line 725 downstream of the four parallel mixing lines 712 to form a common conditioned feed stream 746;

[0202] (4) stopping flow through one or both of the mixing lines 712 and directing or allowing a portion of the heavy oil feedstock 702 to enter bypass line 740, bypassing the parallel mixing lines 712, and merging with the common conditioned feedstock stream 746 in the common discharge line 725; and

[0203] (5) While a portion of the heavy oil feedstock 702 passes through the bypass line 740 , two or three other parallel mixing lines 712 are used to continue mixing at least a portion of the diluted precursor mixture 708 with the remaining portion of the heavy oil feedstock 702 .

[0204] When using Figure 7BAs shown in the alternative mixing system 700, the method alternatively includes the step of premixing the diluted precursor mixture 708 with the heavy oil feedstock 702 using a common static inline mixer 716 upstream of the bifurcation of the first, second, third and fourth mixing lines 712a, 712b, 712c, 712d. The method also omits the use of Fig. 7A Static inline mixers 716a , 716b , 716c , 716d on mixing lines 712a , 712b , 716c , 716d are shown mixing the diluted precursor mixture 708 with the heavy oil feedstock 702 .

[0205] By way of illustration and not limitation, a very large hydroprocessing system may require a heavy oil flow rate of 200 to 400 tons / hour. When operating the first, second, third, and fourth parallel mixing lines 712a, 712b, 712c, 712d, it may be advantageous or preferred to evenly distribute the heavy oil feedstock 702 so that the material flow through each of the parallel mixing lines 712a, 712b, 712c, 712d is symmetrical (e.g., equal) (e.g., 50 tons / hour through each mixing line 712 for a mixing system designed to process 200 tons / hour).

[0206] When one or two of the four mixing lines 712 are closed and offline, a portion of the heavy oil feedstock is rerouted through the bypass line 740 to maintain the same or similar flow rate (approximately 200 to 400 tons / hour) of the heavy oil feedstock 702 through the mixing system 700. By way of example and not limitation, for a mixing system 700 designed for a total flow rate of 200 tons / hour, the flow rate of the heavy oil feedstock 702 through the bypass line 740 and each of the remaining online mixing lines 712 can be the same, such as approximately 50 tons / hour through each line. In a preferred embodiment, the flow rate of the heavy oil feedstock 702 through each of the remaining online mixing lines 712 is increased to more than 50 tons / hour, and the flow rate of the heavy oil feedstock 702 through the bypass line 740 is reduced to less than 50 tons / hour.

[0207] For example, the flow rate through at least one remaining online mixing line 712 can be increased to at least about 52 tons / hour, at least about 54 tons / hour, at least about 56 tons / hour, or at least about 58 tons / hour, such as up to about 60 tons / hour, which is consistent with the capacity limitations of the mixing lines and the mixer. In order to maintain the same or similar flow rate (200 tons / hour) of the heavy oil feedstock through the system when one of the mixing lines 712 is closed, the corresponding flow rate through the bypass line can be about 44 tons / hour or less, or about 38 tons / hour or less, or about 32 tons / hour or less, or about 26 tons / hour or less, such as about 20 tons / hour. In order to maintain the same or similar flow rate (200 tons / hour) of the heavy oil feedstock through the system when two of the mixing lines 712 are closed, the corresponding flow rate through the bypass line can be about 96 tons / hour or less, or about 92 tons / hour or less, or about 88 tons / hour or less, or about 84 tons / hour or less, such as about 80 tons / hour.

[0208] Alternatively, the flow rate of the heavy oil feedstock 702 through the bypass line 740 may be greater than the flow rate through the remaining online mixing line 712. For example, the flow rate through the bypass line 740 may be at least about 55 tons / hour, at least about 60 tons / hour, at least about 65 tons / hour, or at least about 70 tons / hour, such as up to about 75 tons / hour. In order to maintain the same or similar flow rate of the heavy oil feedstock through the system (200 tons / hour), the combined flow rate through the remaining online mixing line 712 may be reduced to about 145 tons / hour or less, or about 140 tons / hour or less, or about 135 tons / hour or less, or about 130 tons / hour or less, such as about 125 tons / hour.

[0209] It should be understood that the mixing system 700 can be scaled up or down depending on the size of the hydroprocessing reactor being fed, and the flow rate is less than or greater than 200 tons / hour. In this case, a percentage of the nominal capacity can be used to describe the flow rate. If 100% represents the nominal flow rate of the heavy oil feedstock 702 through the mixing system 700, the amount of heavy oil feedstock 702 passing through each mixing line 712 during normal operation of the four parallel mixing lines 712a, 712b, 712c, 712d can be about 25% of the total flow rate. When one of the mixing lines 712 is closed and offline, about 25% of the total flow rate can be divided into the bypass line 740, while about 75% of the total flow rate continues to pass through the remaining online mixing lines 712. When two of the mixing lines 712 are closed and offline, about 25-50% of the total flow rate can be divided into the bypass line 740, while about 50-75% of the total flow rate continues to pass through the remaining online mixing lines 712.

[0210] In preferred embodiments, and consistent with the capacity limitations of the mixing lines and mixers, the combined flow through the remaining in-line mixing lines 712 can be increased to at least about 75% of the total flow, at least about 80% of the total flow, at least about 85% of the total flow, or at least about 90% of the total flow, such as up to about 95% of the total flow. To maintain the same or similar flow rate of the heavy oil feedstock through the system, the corresponding flow through the bypass line can be about 25% of the total flow or less, or about 20% of the total flow or less, or about 15% of the total flow or less, or about 10% of the total flow or less, such as about 5% of the total flow.

[0211] Alternatively, the flow rate of the heavy oil feedstock 702 through the bypass line 740 can be greater than the flow rate through each of the remaining in-line mixing lines 712. For example, the flow rate through the bypass line 740 can be at least about 27.5% of the total flow rate through the mixing system 700, at least about 30% of the total flow rate, at least about 32.5% of the total flow rate, or at least about 35% of the total flow rate, such as up to about 37.5% of the total flow rate. In order to maintain the same or similar flow rate of the heavy oil feedstock through the mixing system 700, the combined flow rate through the remaining in-line mixing lines 712 can be reduced to about 72.5% or less of the total flow rate through the mixing system 700, or about 70% or less of the total flow rate, or about 67.5% or less of the total flow rate, or about 65% or less of the total flow rate, such as about 62.5% of the total flow rate.

[0212] In view of the foregoing, each parallel mixing line 712a, 712b, 712c, 712d can have a capacity to operate at a flow rate of about 0-52 tons / hour, or about 0-54 tons / hour, or about 0-56 tons / hour, or about 0-58 tons / hour, or about 0-60 tons / hour. The bypass line 740 can be configured to have a flow capacity of about 0-50 tons / hour, or about 0-55 tons / hour, or about 0-60 tons / hour, or about 0-65 tons / hour, or about 0-70 tons / hour, or about 0-75 tons / hour, or about 0-80 tons / hour, or about 0-90 tons / hour, or about 0-100 tons / hour. Therefore, Fig. 7A and 7B It is shown how the capacity of the mixing system 700 can be increased by approximately 100% without increasing the capacity of each mixing line 712. However, it should be understood that the mixing lines 712 can have a smaller or larger capacity as desired.

[0213] In some embodiments, dispersed metal sulfide catalyst particles are formed in situ in the entire heavy oil added to the hydroprocessing reactor. This can be achieved using the disclosed mixing method and system, first mixing the catalyst precursor with a diluent to form a diluted precursor mixture, then mixing the diluted precursor mixture with the entire heavy oil in multiple parallel mixing lines to form parallel conditioned feedstock streams, which are periodically combined with the heavy oil feedstock from the bypass line into a common conditioned feedstock stream, and then heated to decompose the catalyst precursor and cause or allow the catalyst metal to react with sulfur and / or sulfur-containing molecules in and / or added to the heavy oil to form dispersed metal sulfide catalyst particles in situ.

[0214] The catalyst precursor may be oil soluble and have a decomposition temperature in the range of about 100°C (212°F) to about 350°C (662°F), or in the range of 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). Exemplary catalyst precursors include organometallic complexes or compounds, more specifically oil soluble compounds or complexes of transition metals and organic acids, having a decomposition temperature or decomposition temperature range high enough to avoid substantial decomposition when mixed with a heavy oil feedstock under suitable mixing conditions. When the catalyst precursor is mixed with a hydrocarbon oil diluent, it is advantageous to maintain the diluent below the temperature at which the catalyst precursor undergoes significant decomposition. One skilled in the art can select a mixing temperature profile that allows the selected precursor composition to be thoroughly mixed without significant decomposition prior to forming dispersed metal sulfide catalyst particles in situ.

[0215] Example catalyst precursors include, but are not limited to, 2-ethylhexanoic acid molybdenum, octanoic acid molybdenum naphthenate, vanadium naphthenate, octanoic acid vanadium, hexacarbonyl molybdenum, hexacarbonyl vanadium, and pentacarbonyl iron. Other catalyst precursors include molybdenum salts comprising a plurality of cationic molybdenum atoms and a plurality of carboxylate anions of at least 8 carbon atoms, and being at least one of (a) aromatic, (b) alicyclic, or (c) branched unsaturated aliphatic. For example, each carboxylate anion may have 8 to 17 carbon atoms or 11 to 15 carbon atoms. Examples of carboxylate anions that meet at least one of the aforementioned categories include carboxylate anions derived from carboxylic acids selected from the group consisting of: 3-cyclopentylpropionic acid, cyclohexanebutyric acid, biphenyl-2-carboxylic acid, 4-heptylbenzoic acid, 5-phenylpentanoic acid, geranic acid (3,7-dimethyl-2,6-octadienoic acid), and combinations thereof.

[0216] In other embodiments, carboxylate anions suitable for preparing oil-soluble, thermally stable platinum catalyst precursor compounds are derived from carboxylate anions of carboxylic acids selected from the group consisting of 3-cyclopentylpropionic acid, cyclohexanebutyric acid, biphenyl-2-carboxylic acid, 4-heptylbenzoic acid, 5-phenylpentanoic acid, geranic acid (3,7-dimethyl-2,6-octadienoic acid), 10-undecenoic acid, dodecanoic acid, and combinations thereof. It has been found that platinum catalyst precursors prepared using carboxylate anions derived from the foregoing carboxylic acids have improved thermal stability.

[0217] Catalyst precursors with higher thermal stability may have a first decomposition temperature above 210° C., above about 225° C., above about 230° C., above about 240° C., above about 275° C., or above about 290° C. Such catalyst precursors may have a peak decomposition temperature above 250° C., or above about 260° C., or above about 270° C., or above about 280° C., or above about 290° C., or above about 330° C.

[0218] In some embodiments, the conditioned feedstock is preheated using a heating device prior to entering the hydroprocessing reactor so as to form at least a portion of the dispersed metal sulfide catalyst particles in situ in the heavy oil prior to entering the reactor. In other embodiments, the conditioned feedstock may be heated or further heated in the hydroprocessing reactor so as to form at least a portion of the dispersed metal sulfide catalyst particles in situ in the heavy oil.

[0219] Using the disclosed mixing method and system, dispersed metal sulfide catalyst particles are formed in a multi-step process. First, an oil-soluble catalyst precursor is premixed with a hydrocarbon diluent to form a diluted precursor mixture. Examples of suitable hydrocarbon diluents include, but are not limited to, vacuum gas oils (which typically have a nominal boiling range of 360-524°C (680-975°F)), decant oil or cycle oil (which typically have a nominal boiling range of 360-550°C (680-1022°F)), and atmospheric gas oils (which typically have a nominal boiling range of 200-360°C (392-680°F)), a portion of heavy oil feedstock, and other hydrocarbons having a nominal boiling point at a temperature above about 200°C.

[0220] The ratio of catalyst precursor to hydrocarbon oil diluent used to prepare the diluted precursor mixture can be in the range of about 1:500 to about 1:1, or in the range of about 1:150 to about 1:2, or in the range of about 1:100 to about 1:5 (e.g., 1:100, 1:50, 1:30, or 1:10). The amount of catalyst metal (e.g., platinum) in the diluted precursor mixture is preferably in the range of about 100 ppm to about 7000 ppm, more preferably in the range of about 300 ppm to about 4000 ppm, based on the weight of the diluted precursor mixture.

[0221] The catalyst precursor is advantageously mixed with the hydrocarbon diluent at a temperature below the temperature at which a substantial portion of the catalyst precursor decomposes. The mixing may be conducted at a temperature in the range of about 25°C (77°F) to about 250°C (482°F), or in the range of about 50°C (122°F) to about 200°C (392°F), or in the range of about 75°C (167°F) to about 150°C (302°F). The temperature at which the diluted precursor mixture is formed may depend on the decomposition temperature and / or other properties of the catalyst precursor used and / or the properties of the hydrocarbon diluent, such as viscosity.

[0222] The catalyst precursor is preferably mixed with the diluent for a period of about 0.1 seconds to about 5 minutes, or about 0.3 seconds to about 3 minutes, or about 0.5 seconds to about 1 minute, or about 0.7 seconds to about 30 seconds, or about 1 second to about 10 seconds. The actual mixing time depends at least in part on the temperature (i.e., the temperature that affects the viscosity of the fluid) and the mixing intensity. The mixing intensity depends at least in part on the number of stages, such as for an in-line static mixer.

[0223] Premixing the catalyst precursor with a hydrocarbon diluent to form a diluted precursor mixture and then mixing the diluted precursor mixture with the heavy oil feedstock greatly aids in thoroughly and intimately mixing the catalyst precursor into the feedstock, particularly in the relatively short time required for large-scale commercial operations. Forming a diluted precursor mixture reduces the overall mixing time by: (1) reducing or eliminating solubility differences between the more polar catalyst precursor and the more hydrophobic heavy oil feedstock, (2) reducing or eliminating rheological differences between the catalyst precursor and the heavy oil feedstock, and / or (3) decomposing the catalyst precursor molecules to form a solute in the hydrocarbon diluent that is more easily dispersed in the heavy oil feedstock.

[0224] The diluted precursor mixture is mixed with the heavy oil and mixed for a sufficient time to disperse the catalyst precursor throughout the heavy oil to form a conditioned feedstock, wherein the catalyst precursor is thoroughly mixed with the feedstock prior to thermal decomposition and in situ formation of active metal sulfide catalyst particles. In order to obtain thorough mixing of the catalyst precursor in the feedstock, the diluted precursor mixture and the feedstock are advantageously mixed for a period of time in the range of about 0.1 seconds to about 5 minutes, or in the range of about 0.5 seconds to about 3 minutes, or in the range of about 1 second to about 1 minute. Increasing the severity and / or shear energy of the mixing process generally reduces the time required to achieve thorough mixing.

[0225] Examples of mixing devices that can be used to achieve thorough mixing of the diluted precursor mixture with the heavy oil include, but are not limited to, high shear mixing, such as mixing produced in a vessel having a propeller or turbine impeller; a static inline mixer; a combination of a static inline mixer and an inline high shear mixer; a combination of a static inline mixer and an inline high shear mixer followed by a buffer tank; a combination of the foregoing followed by one or more multistage centrifugal pumps; and one or more multistage centrifugal pumps. According to some embodiments, continuous rather than batch mixing can be performed using a high energy pump having multiple chambers in which the catalyst precursor and heavy oil feedstock are agitated and mixed as part of the pumping process itself. The above mixing devices can also be used in the above premixing process, where the catalyst precursor is mixed with a hydrocarbon diluent to form a catalyst precursor mixture.

[0226] In the case where the heavy oil feedstock is solid or extremely viscous at room temperature, it may be advantageous to heat such feedstocks to soften them and produce a feedstock with a sufficiently low viscosity to allow the oil-soluble catalyst precursor to be well mixed into the feedstock. Generally speaking, reducing the viscosity of the heavy oil feedstock will reduce the time required for the oil-soluble precursor composition to be fully and intimately mixed in the feedstock. However, it may also result in premature decomposition of the catalyst precursor. A catalyst precursor may be selected that has a decomposition temperature suitable for a given heavy oil feedstock.

[0227] The heavy oil feedstock and catalyst precursor and / or diluted precursor mixture are advantageously mixed at a temperature in the range of about 25°C (77°F) to about 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 produce a conditioned feedstock.

[0228] Because the catalyst precursor is premixed with a hydrocarbon diluent to form a diluted precursor mixture, which is then mixed with the heavy oil feedstock, the feedstock can be at or above the decomposition temperature of the catalyst precursor. In some cases, the hydrocarbon diluent protects individual catalyst precursor molecules, prevents them from aggregating to form larger particles, temporarily isolates the catalyst precursor molecules from heat from the heavy oil during mixing, and promotes the catalyst precursor molecules to disperse quickly enough throughout the feedstock before decomposing to release metals. In addition, additional heating of the feedstock may be required to release hydrogen sulfide from sulfur-containing molecules in the heavy oil to form metal sulfide catalyst particles. In this way, the gradual dilution of the catalyst precursor allows for high dispersion in the heavy oil, thereby forming highly dispersed metal sulfide catalyst particles, even if the feedstock is at a temperature above the decomposition temperature of the catalyst precursor.

[0229] After the catalyst precursor has been fully mixed throughout the heavy oil to produce a conditioned feedstock, the composition is heated to cause the decomposition of the catalyst precursor, which releases the catalyst metal therefrom, allowing or allowing the catalyst metal to react with sulfur in and / or added to the heavy oil, and forming active metal sulfide catalyst particles in situ. The metal from the catalyst precursor can initially form a metal oxide, which then reacts with the sulfur in the heavy oil to produce a metal sulfide compound, which forms the final active catalyst. In the case where the heavy oil contains enough or excessive sulfur, the final activated catalyst can be formed in situ by heating the feedstock to a temperature sufficient to release sulfur therefrom. In some cases, sulfur can be released at the same temperature at which the catalyst precursor decomposes. In other cases, further heating to a higher temperature may be required. Hydrogen sulfide gas can be added to the heavy oil lacking enough sulfur to form active metal sulfide catalyst particles.

[0230] If the catalyst precursor is thoroughly mixed in the heavy oil, at least most of the released metal ions will be sufficiently protected or shielded from the influence of other metal ions so that they can form a molecularly dispersed catalyst when reacting with sulfur to form metal sulfides. In some cases, slight agglomeration may occur, resulting in colloidal-sized catalyst particles. However, it is believed that before the catalyst precursor is thermally decomposed, taking care to thoroughly mix the catalyst precursor throughout the feedstock can produce individual catalyst molecules, rather than colloidal particles. Simply mixing the catalyst precursor with the feedstock without sufficient mixing usually results in the formation of large agglomerated metal sulfides of micrometer size or larger.

[0231] 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 of about 330°C (626°F) to about 410°C (770°F).

[0232] The concentration of catalyst metal provided by the dispersed metal sulfide catalyst particles in the heavy oil may be in the range of about 1 ppm to about 150 ppm by weight of the heavy oil and any diluent, or in the range of about 5 ppm to about 95 ppm by weight, or in the range of about 10 ppm to about 90 ppm by weight.

[0233] In the case where the heavy oil contains a large number of asphaltene molecules, the dispersed metal sulfide catalyst particles may preferentially bind to or remain in close proximity with the asphaltene molecules. Asphaltene molecules may have a greater affinity for the metal sulfide catalyst particles because asphaltene molecules are generally more hydrophilic and less hydrophobic than other hydrocarbons contained in the heavy oil. Because the metal sulfide catalyst particles tend to be hydrophilic, individual particles or molecules will tend to migrate toward the more hydrophilic portions or molecules in the heavy oil.

[0234] Although the highly polar nature of the metal sulfide catalyst particles causes or allows them to bind to asphaltene molecules, the general incompatibility between highly polar catalyst compounds and hydrophobic heavy oils makes it necessary to perform the aforementioned adequate or thorough mixing of the catalyst precursor in the feedstock prior to decomposition and in situ formation of active catalyst particles. Because the metal catalyst compounds are highly polar, they cannot be effectively dispersed in the heavy oil if added directly. In fact, the formation of smaller active catalyst particles leads to a larger number of catalyst particles, thereby providing more evenly distributed catalyst sites throughout the heavy oil. It also increases the surface area of ​​the catalyst.

[0235] Thorough mixing of the catalyst precursor with the heavy oil feedstock prior to thermal decomposition of the catalyst precursor and formation of dispersed metal sulfide catalyst particles significantly reduces the rate of equipment fouling, which rate can be measured by at least one of the following: (i) the frequency of required heat exchanger cleaning; (ii) the frequency of switching to a backup heat exchanger; (iii) the frequency of filter replacement; (iv) the frequency of coarse filter cleaning or replacement; (v) the rate of decrease in equipment surface temperature, the equipment including equipment selected from the group consisting of heat exchangers, separators, or distillation columns; (vi) the rate of increase in furnace tube metal temperature; (vii) the rate of increase in the calculated fouling thermal resistance coefficient of heat exchangers and furnaces; (viii) the rate of increase in heat exchanger pressure differentials; (ix) the frequency of cleaning atmospheric and / or vacuum distillation columns; or (x) the frequency of maintenance turnover.

[0236] V. Examples

[0237] Comparative Example 1

[0238] This embodiment includes a conventional mixing system comprising a single mixing line, no parallel mixing lines, and no bypass lines. The mixing line includes one or more high shear mixers, one or more strainers or filters, one or more static inline mixers, and optionally other processing equipment known in the art. At some point during the operation of the single mixing line, the mixing line requires a maintenance interval. For example, maintenance may include at least one of cleaning one or more strainers or filters, cleaning and / or repairing the high shear mixer, and cleaning and / or repairing the static inline mixer.

[0239] Regardless of which portion or section of the mixing line is shut down, the mixing line is longer in line and the mixing of the catalyst precursor into the heavy oil feedstock is stopped. Closing the mixing line for maintenance may have one or more results or consequences, including completely stopping the flow of the diluted precursor mixture into the heavy oil feedstock. Doing so may reduce the feed rate of hydrocarbon material to the hydroprocessing reactor downstream of the mixing line, thereby reducing production capacity and / or liquid hourly space velocity.

[0240] Another result or consequence is to continue to add the diluted precursor mixture to the heavy oil feedstock at the same rate. Doing so maintains the same rate at which the hydrocarbon material is fed into the hydroprocessing reactor, thereby maintaining the throughput and / or liquid hourly space velocity. However, this is only possible if the mixing system is equipped with a bypass line, which is a feature not included in conventional mixing systems currently used to introduce catalyst precursors into heavy oil. However, even if such a bypass line is added to an existing single-line mixing system, the diluted precursor mixture is rarely or not significantly mixed into the heavy oil, resulting in the hydrocarbon material fed to the preheater and / or hydroprocessing reactor containing a concentrated region of the diluted precursor mixture, which contains a more concentrated form of the catalyst precursor than when the mixing line is online. If the more concentrated form of the diluted precursor mixture is then exposed to high temperatures to cause decomposition of the catalyst precursor, this will result in the formation of substantially larger homogeneous catalyst particles, for example, 1-300 μm in size, compared to the size of the dispersed metal sulfide catalyst particles formed in situ when the diluted precursor mixture is thoroughly mixed into the heavy oil feedstock before the catalyst precursor is thermally decomposed.

[0241] Another alternative outcome or consequence is to continue to add the hydrocarbon diluent without the catalyst precursor to the heavy oil feedstock at the same rate. Again, this would require the addition of a bypass line to a conventional mixing system that does not include a bypass line. Doing so would essentially maintain the same rate at which the hydrocarbon material is fed to the hydroprocessing reactor, thereby essentially maintaining throughput and / or liquid hourly space velocity. However, in the absence of the catalyst precursor, dispersed metal sulfide catalyst particles or other homogeneous catalyst would not be formed in situ in the heavy oil feedstock. In this case, there would no longer be such an in situ formed catalyst in the hydroprocessing system, and instead one would have to rely on an ebullating bed catalyst, a fixed bed catalyst, or other catalyst already used in the hydroprocessing reactor.

[0242] Another alternative is some type of mixing that reduces, but does not completely stop, the flow of the diluted precursor mixture into the heavy oil and / or the flow of the catalyst precursor into the hydrocarbon diluent. Any such alternative would rely on the addition of a bypass line to a conventional mixing system that does not include a bypass line. They would also substantially eliminate the in-situ formation of dispersed metal sulfide catalyst particles having a particle size of less than 1 μm in the heavy oil feedstock.

[0243] Comparative Example 2

[0244] This embodiment includes a mixing system that includes two full-scale mixing lines that operate independently of each other to mix the entire catalyst precursor mixture into the heavy oil feedstock. Each full-scale mixing line includes one or more high shear mixers, one or more strainers or filters, one or more static inline mixers, and optionally other processing equipment known in the art. When one full-scale mixing line is online and running, the other is offline, and vice versa. In this way, whenever one mixing line needs maintenance, the other mixing line performs the entire mixing process with the same mixing efficiency.

[0245] Although providing two full-scale mixing lines would solve many or most of the problems in Comparative Example 1, such a mixing system is expensive and wasteful, having twice the mixing capacity but at approximately twice the cost, with half of the mixing system remaining offline and dormant at any given time, even when no maintenance is being performed.

[0246] Example 3

[0247] This embodiment relates to a hybrid system of the present invention, which includes two parallel mixing lines and a bypass line. Each mixing line includes one or more high shear mixers, one or more strainers or filters, optional one or more static inline mixers and optional other processing equipment known in the art. The hybrid system can optionally include a common static inline mixer located upstream of the bifurcation of the two parallel mixing lines. At different times during the hybrid system operation, one of the two parallel mixing lines will need maintenance. For example, the maintenance interval can include cleaning one or more strainers or filters, cleaning and / or repairing high shear mixers and cleaning and / or repairing at least one of the static inline mixers.

[0248] Regardless of which portion or section of the mixing line is shut down, the mixing line being maintained is taken offline and mixing of the catalyst precursor into the heavy oil feedstock through that line is stopped. However, the other parallel mixing lines remain online to continue mixing the diluted precursor mixture with at least 50% of the heavy oil feedstock to form a conditioned feedstock, with the remaining 50% or less of the feedstock being diverted through a bypass line to rejoin the conditioned feedstock downstream of the remaining mixing lines. Although the mixing efficiency may be reduced when one parallel mixing line is taken offline, the overall mixing process is significantly improved relative to Comparative Example 1 because the mixing system of Example 3 is still able to provide a conditioned feedstock with dispersed metal sulfide catalyst particles formed in situ in the heavy oil feedstock. In addition, the production rate and / or liquid hourly space velocity can be more easily maintained compared to Comparative Example 1.

[0249] Although diverting a portion of the heavy oil feedstock through the bypass line during maintenance intervals may reduce the overall mixing efficiency of the mixing system, the reduction in overall mixing efficiency can be partially mitigated by increasing the flow through the remaining mixing lines, depending on their capacity limitations, which increases the mixing efficiency of the remaining mixing lines compared to maintaining the flow through the mixing lines at approximately 50% of the total flow through the mixing system.

[0250] For example, when operating the parallel mixing lines, each mixing line can be operated to mix the diluted catalyst precursor mixture into about 50% of the total volume of the heavy oil feedstock flowing through the mixing system. However, when one of the mixing lines is shut down for maintenance, the remaining parallel mixing lines can be temporarily operated at a higher flow rate (subject to their capacity) to mix the diluted precursor mixture with a larger amount of the heavy oil feedstock, such as about 55%, 60%, 65%, 70% or 75% of the total volume of the heavy oil feedstock flowing through the mixing system, with the remaining heavy oil feedstock (about 45%, 40%, 35%, 30% or 25%, respectively) flowing through the bypass line to keep the total throughput of heavy oil through the mixing system and / or the liquid hourly space velocity of the heavy oil through the hydroprocessing reactor the same.

[0251] Example 4

[0252] This embodiment relates to a hybrid system of the present invention, which includes three parallel mixing lines and a bypass line. Each mixing line includes one or more high shear mixers, one or more strainers or filters, optional one or more static inline mixers and optional other processing equipment known in the art. The hybrid system can optionally include a common static inline mixer located upstream of the three parallel mixing lines bifurcation. At different times during the hybrid system operation, one of the three parallel mixing lines will need maintenance. For example, the maintenance interval can include cleaning one or more strainers or filters, cleaning and / or repairing high shear mixers and cleaning and / or repairing at least one of the static inline mixers.

[0253] Regardless of which portion or section of the mixing line is shut down, the mixing line being maintained is taken offline and the mixing of the catalyst precursor into the heavy oil feedstock through that line is stopped. However, the other parallel mixing lines remain online to continue mixing the diluted precursor mixture with at least 67% of the heavy oil feedstock to form a conditioned feedstock, with the remaining 33% or less of the feedstock being diverted through a bypass line to rejoin the conditioned feedstock downstream of the remaining mixing lines. Although the mixing efficiency may be reduced when one parallel mixing line is taken offline, the overall mixing process is significantly improved relative to Comparative Example 1 because the mixing system of Example 4 is still able to provide a conditioned feedstock with dispersed metal sulfide catalyst particles formed in situ in the heavy oil feedstock. In addition, production capacity and / or liquid hourly space velocity can be more easily maintained.

[0254] Although diverting a portion of the heavy oil feedstock through the bypass line during maintenance intervals may reduce the overall mixing efficiency of the mixing system, the reduction in overall mixing efficiency can be partially mitigated by increasing the flow through the remaining mixing lines, depending on their capacity limitations. This increases the mixing efficiency of each remaining mixing line compared to maintaining the flow through the mixing line at approximately 33% of the total flow through the mixing system.

[0255] For example, when operating the parallel mixing lines, each mixing line can be operated to mix the diluted catalyst precursor mixture into about 33% of the total volume of the heavy oil feedstock flowing through the mixing system. However, when one of the parallel mixing lines is shut down for maintenance, the remaining mixing line can be temporarily operated at a higher flow rate (subject to its capacity) to mix the diluted precursor mixture with a larger amount of the heavy oil feedstock, such as about 70%, 75%, 80%, 85% or 90% of the total volume of the heavy oil feedstock flowing through the mixing system, with the remaining heavy oil feedstock (about 30%, 25%, 20%, 15% or 10% of the total volume, respectively) flowing through the bypass line to keep the total throughput of heavy oil through the mixing system and / or the liquid hourly space velocity of the heavy oil through the hydroprocessing reactor the same.

[0256] Example 5

[0257] This embodiment relates to a hybrid system of the present invention, which includes four parallel mixing lines and a bypass line. Each mixing line includes one or more high shear mixers, one or more strainers or filters, optional one or more static inline mixers and optional other processing equipment known in the art. The hybrid system can optionally include a common static inline mixer located upstream of the four parallel mixing lines bifurcation. At different times during the hybrid system operation, one of the four parallel mixing lines will need maintenance. For example, the maintenance interval can include cleaning one or more strainers or filters, cleaning and / or repairing high shear mixers and cleaning and / or repairing at least one of the static inline mixers.

[0258] Regardless of which portion or section of the mixing line is shut down, the mixing line being maintained is taken offline and the mixing of the catalyst precursor into the heavy oil feedstock through that line is stopped. However, the other parallel mixing lines remain online to continue mixing the diluted precursor mixture with at least 75% of the heavy oil feedstock to form a conditioned feedstock, with the remaining 25% or less of the feedstock being diverted through a bypass line to rejoin the conditioned feedstock downstream of the remaining mixing lines. Although the mixing efficiency may be reduced when one parallel mixing line is taken offline, the overall mixing process is significantly improved relative to Comparative Example 1 because the mixing system of Example 5 is still able to provide a conditioned feedstock with dispersed metal sulfide catalyst particles formed in situ in the heavy oil feedstock. In addition, production capacity and / or liquid hourly space velocity can be more easily maintained.

[0259] Although the diversion of a portion of the heavy oil feedstock through the bypass line during the maintenance interval may reduce the overall mixing efficiency of the mixing system, the reduction in the overall mixing efficiency can be partially or substantially mitigated by increasing the flow through the remaining mixing lines, depending on their capacity limitations, thereby increasing the mixing efficiency of each of the remaining mixing lines compared to maintaining the flow through the mixing line at approximately 25% of the total flow through the mixing system.

[0260] For example, when operating the parallel mixing lines, each mixing line can be operated to mix the diluted catalyst precursor mixture into about 25% of the total volume of the heavy oil feedstock flowing through the mixing system. However, when one of the parallel mixing lines is shut down for maintenance, the remaining mixing line can be temporarily operated at a higher flow rate (subject to its capacity) to mix the diluted precursor mixture with a larger amount of the heavy oil feedstock, such as about 77%, 80%, 83%, 86%, 89%, 92% or 95% of the total volume of the heavy oil feedstock flowing through the mixing system, with the remaining heavy oil feedstock (about 23%, 20%, 17%, 14%, 11%, 8% or 5% of the total volume, respectively) flowing through the bypass line to keep the total throughput of heavy oil through the mixing system and / or the liquid hourly space velocity of the heavy oil through the hydroprocessing reactor the same.

[0261] The present invention may be implemented in other specific forms without departing from the spirit or essential features of the present invention. The described embodiments are considered to be illustrative and non-restrictive in all aspects. Therefore, the scope of the present invention is represented by the appended claims rather than the preceding description. All changes within the meaning and scope of the equivalents of the claims are included within the scope of the claims.

Claims

1. A method for mixing a catalyst precursor into heavy oil, comprising: mixing a certain amount of a catalyst precursor with a certain amount of a diluent to form a diluted precursor mixture; mixing the diluted precursor mixture with the heavy oil feedstock using a plurality of parallel mixing lines to form a plurality of conditioned feedstock streams, each parallel mixing line comprising one or more mixers and at least one valve for regulating flow in the mixing line; combining the conditioned feedstock streams in a common discharge line downstream of the parallel mixing lines to form a common conditioned feedstock stream; stopping flow through one blending line and directing or allowing a portion of the heavy oil feedstock to enter a bypass line, bypass the parallel blending lines, and combine with a common conditioned feedstock stream in a common discharge line; and While a portion of the heavy oil feedstock flows through the bypass line, at least a portion of the diluted precursor mixture continues to be mixed with the remaining portion of the heavy oil feedstock using at least one other parallel mixing line. 2 . The method of claim 1 , wherein the parallel mixing line comprises two or more parallel mixing lines.

3. The method of claim 1 or 2, wherein the parallel mixing lines comprise three or more parallel mixing lines.

4. The process according to any one of claims 1 to 3, wherein each parallel mixing line comprises a high shear mixer and optionally a static inline mixer and / or a strainer.

5. The method of any one of claims 1 to 4, wherein stopping flow through a mixing line comprises closing one or more valves of the mixing line and performing maintenance on the mixing line.

6. The method according to any one of claims 1 to 5, wherein a portion of the heavy oil feedstock is directed into a bypass line, bypasses the parallel mixing lines, and is combined with a common conditioned feedstock stream in the common discharge line by partially closing one or more valves connected to one or more operating parallel mixing lines and / or common discharge lines to restrict flow and / or increase upstream pressure.

7. The method of any one of claims 1 to 6, further comprising mixing the same or similar amount of the diluted precursor mixture with the remaining portion of the heavy oil feedstock when one of the mixing lines is closed and a portion of the heavy oil feedstock bypasses the mixing line and recombines with the common conditioned feedstock stream in the common discharge line.

8. The method of any one of claims 1 to 7, further comprising measuring flow through the common discharge line using a first flow meter, and measuring flow through the bypass line using a second flow meter.

9. The method of any one of claims 1 to 8, further comprising measuring the flow rate through each parallel mixing line using a respective flow meter connected to the parallel mixing line.

10. The method according to any one of claims 1 to 9, further comprising adjusting flow through one or more of the parallel mixing lines, the common discharge line or the bypass line by adjusting one or more valves connected to the parallel mixing lines, the common discharge line or the bypass line.

11. The method of any one of claims 1 to 10, further comprising using a portion of the heavy oil feedstock as a diluent to form a diluted precursor mixture.

12. The method of any one of claims 1 to 11, further comprising introducing the common conditioned feedstock stream from the common discharge line and any heavy oil feedstock from the bypass line into a surge tank, which causes or allows the catalyst precursor to further mix throughout the heavy oil feedstock.

13. The method of claim 12, further comprising using a portion of the conditioned feedstock from the buffer tank as a diluent to form the diluted precursor mixture.

14. The method of any one of claims 1 to 13, further comprising heating the conditioned feedstock downstream of the common discharge line to decompose catalyst precursors and form dispersed metal sulfide catalyst particles throughout the heavy oil feedstock.

15. The method of any one of claims 1 to 14, further comprising causing or allowing the catalyst precursor to form dispersed metal sulfide catalyst particles in situ in the heavy oil feedstock, and hydrotreating the heavy oil feedstock under hydrotreating conditions to form converted products, the dispersed metal sulfide catalyst particles promoting beneficial upgrading reactions.

16. The method according to claim 15, wherein the hydroprocessing is carried out by at least one hydroprocessing reactor selected from the group consisting of a slurry phase reactor, an ebullated bed reactor and a fixed bed reactor.

17. The method of any one of claims 14 to 16, wherein the dispersed metal sulfide catalyst particles are less than 1 μm in size, or less than about 500 nm in size, or less than about 250 nm in size, or less than about 100 nm in size, or less than about 50 nm in size, or less than about 25 nm in size, or less than about 10 nm in size.

18. A system for mixing a catalyst precursor into heavy oil, comprising: at least one mixer configured to receive an amount of catalyst precursor and mix it with an amount of diluent to form a diluted precursor mixture; a plurality of parallel mixing lines configured to receive the diluted precursor mixture and mix it with the heavy oil feedstock to form a plurality of conditioned feedstock streams, each parallel mixing line comprising one or more mixers and at least one valve for regulating flow in the mixing line; a common discharge line configured to receive and combine the conditioned feedstock streams from the parallel mixing lines to form a common conditioned feedstock stream; and a bypass line configured to receive a portion of the heavy oil feedstock when flow through at least one of the parallel mixing lines is stopped, cause the portion of the heavy oil feedstock to bypass the parallel mixing lines, and combine the bypassed portion of the heavy oil feedstock with a common conditioned feedstock stream in the common discharge line, The system is configured such that when one of the mixing lines is closed and the portion of the heavy oil feedstock flows through the bypass line, the remaining portion of the heavy feedstock continues to mix with the diluted precursor mixture through at least one other parallel mixing line.

19. The system of claim 18, wherein the parallel mixing lines comprise at least two, such as three or four, parallel mixing lines.

20. The system of claim 18 or 19, wherein each parallel mixing line comprises a high shear mixer and optionally a static inline mixer and / or a strainer.

21. The system of any one of claims 18 to 20, wherein each parallel mixing line comprises one or more valves configured to close to stop flow through the mixing line and to allow maintenance and / or partial closure of the mixing line to regulate flow through the mixing line.

22. The system according to any one of claims 18 to 21, further comprising one or more valves connected to the parallel mixing lines and / or the common discharge line and configured to restrict flow and / or increase upstream pressure to allow a portion of the heavy oil feedstock to enter the bypass line, bypass the parallel mixing lines, and enter the common discharge line.

23. The system of any one of claims 18 to 22, further comprising a first flow meter connected to the common discharge line and a second flow meter connected to the bypass line.

24. The system of claim 23, further comprising a flow meter connected to each parallel mixing line.

25. The system of any one of claims 18 to 24, further comprising one or more valves connected to the common drain line and the bypass line to regulate flow through the bypass line and the common drain line.

26. The system of any one of claims 18 to 25, further comprising a buffer tank configured to receive the common conditioned feed stream from the common discharge line and any heavy oil feed from the bypass line, and to cause or allow the catalyst precursor to further mix throughout the heavy oil feed.

27. The system of any one of claims 18 to 26, further comprising a bleed line configured to provide a portion of the heavy oil feedstock stream as a diluent to form a diluted precursor mixture.

28. The system of any one of claims 18 to 27, further comprising a recycle line configured to provide a portion of the common conditioned feedstock stream and optionally a heavy oil feedstock from the bypass line as a diluent to form a diluted precursor mixture.

29. The system of any one of claims 18 to 28, further comprising a heater downstream of the common discharge line, the heater being configured to heat the common conditioned feedstock stream to decompose catalyst precursors and form dispersed metal sulfide catalyst particles in situ in the heavy oil feedstock.

30. The system of any one of claims 18 to 29, further comprising one or more hydroprocessing reactors configured to receive the heavy oil feedstock and hydroprocess it under hydroprocessing conditions to form converted products, wherein the dispersed metal sulfide catalyst particles formed in situ from the catalyst precursor promote beneficial upgrading reactions.

31. The system of claim 30, wherein the one or more hydroprocessing reactors are selected from the group consisting of a slurry phase reactor, an ebullated bed reactor, and a fixed bed reactor, and combinations thereof.

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