Use of a continuous catalyst regenerating reformer for the AROMAX® catalytic process.

Abstract

FIELD OF THE DISCLOSURE This disclosure relates to the aromatization of hydrocarbons with an aromatization catalyst, including aromatization processes that involve the use of a continuously catalyst regenerating reformer.

Description

[Background technology]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS Not applicable.

[0002] The catalytic conversion of non-aromatic hydrocarbons into aromatic compounds, known as aromatization, is an important industrial process used to produce the basic chemicals upon which much of the chemical industry is based. Aromatization reactions can include hydrocarbon dehydrogenation, isomerization, and hydrocracking, each of which produces specific aromatic compounds. These reactions are typically carried out in one or more aromatization reactors containing aromatization catalysts. These catalysts may increase the selectivity to the desired aromatic compounds and / or the conversion rate of the reaction to the desired aromatic compounds. Under commercial aromatization conditions, these catalysts gradually lose activity, as evidenced by a decrease in selectivity to the desired products, endothermic reactions, and / or a decrease in conversion rate. For example, catalysts may become poisoned by the presence of contaminants, reducing their activity. Continued use of catalysts can result in catalysts that no longer efficiently catalyze the user's desired process and / or produce significant by-products, referred to as spent catalysts. Given their commercial importance and the costs associated with producing fresh or regenerated catalysts and replacing spent catalysts, there is a continuing need for improved systems and methods for efficiently utilizing aromatization catalysts. Summary of the Invention

[0003] A particular aspect of the present disclosure relates to a method for operating a reforming reactor system, wherein each reactor stack comprises at least two stacked radial flow reactors, each containing a reforming catalyst capable of catalyzing the conversion of hydrocarbons in a hydrocarbon feed and providing a reactor effluent containing aromatic hydrocarbons, the reforming catalyst comprising a Group VIII metal, a zeolite support, and at least one halogen. In a related embodiment, the method includes operating the reactors of the stacked reactor system by operating the radial flow reactors as stationary fixed beds so that the reforming catalyst is fixed, i.e., does not move during run-time operation. In an additional aspect, the hydrocarbons in the hydrocarbon feed include convertible hydrocarbons selected from 6- or 7-carbon atom hydrocarbons, i.e., C6 or C7 hydrocarbons, having no internal quaternary carbons, and C6 hydrocarbons having no adjacent internal tertiary carbons. A further embodiment relates to operating the reforming reactor system to convert the convertible hydrocarbons in the hydrocarbon feed until the reforming catalyst is determined to be a spent reforming catalyst.

[0004] The method may further include, after the catalyst is determined to be exhausted, ceasing the introduction of the hydrocarbon feed, purging the reactor until the reactor effluent contains less than about 200 ppm hydrocarbons, allowing the reactor to reach ambient temperature, removing the spent reforming catalyst within the radial flow reactor of each reactor stack via inter-stack transfer, either through the bottom radial flow reactor of each reactor stack or through the bottom reactor of the final reactor stack, allowing the catalyst to flow downward through the stack of at least one radial flow reactor for removal, and adding fresh reforming catalyst via inter-stack transfer to the top of the top radial flow reactor of each reactor stack or the top radial flow reactor of the first reactor stack, and allowing the fresh reforming catalyst to flow downward through the stack of at least one radial flow reactor. The method may further involve, in embodiments, the use of a reforming reactor system including at least one purge chamber fluidly attached to the bottom radial flow reactor of each reactor stack, or the bottom reactor of the final reactor stack, but where transfer occurs between stacks and spent reforming catalyst is removed from the bottom radial flow reactor through the purge chamber before the catalyst is removed from the stacked reactor system.

[0005] In certain embodiments, the purge chamber of the reactor system is optionally purged with a gas comprising hydrogen, nitrogen, argon, helium, or a combination thereof. In a related aspect, the reforming reactor system includes a first purge chamber upstream of and fluidly connected to the second purge chamber. In yet further embodiments, purging the reactor system can include purging the first purge chamber with a first purge gas and purging the second purge chamber with a second purge gas, which can be the same or different. For example, in a non-limiting aspect, the first purge gas comprises hydrogen and the second purge gas comprises nitrogen, or the first purge gas comprises nitrogen and the second purge gas comprises hydrogen. In some embodiments, the stacked reactor systems described herein further include a purge chamber fluidly connected to the top radial flow reactor of each reactor stack, or the top reactor of the first reactor stack, where transfer occurs between stacks and fresh reforming catalyst is beneficially added to the top radial flow reactor through the purge chamber and purged with a purge gas comprising one or more of hydrogen, nitrogen, argon, and / or helium, in related aspects including nitrogen as a stand-alone purge gas.

[0006] Zeolite support(s) for use in accordance with the disclosed methodology can include, in a non-limiting aspect, the use of a silica-bound L-zeolite support. In additional embodiments, the stacked reactor systems disclosed herein are advantageously operable to provide for the transfer of reforming catalyst through at least one reactor stack over a significant period of time, including at least about 180 days, at least about 270 days, at least about 365 days, or more than 365 days. The stacked reactor systems are further operable, in certain aspects, to provide for the transfer of reforming catalyst through at least one reactor stack and to a regeneration system via a catalyst transfer system. Accordingly, embodiments relating to the catalyst transfer system include transferring the reforming catalyst to a regeneration system by inter-stack transfer through at least one purge chamber attached to the bottom radial flow reactor of each of the at least one reactor stack or the bottom radial flow reactor of the last of the at least one reactor stack.

[0007] In certain aspects, the catalyst transfer system is arranged or positioned to fluidly connect at least one purge chamber with the top of the regeneration system, as further described herein, thereby transferring the reforming catalyst through the catalyst transfer system. The regeneration system may best be controlled by an operator and / or an operating or control system, including embodiments in which the transfer of the reforming catalyst is intermittent. A further aspect of the disclosed technology relates to transferring the reforming catalyst of one stack of at least one radial flow reactor via the catalyst transfer system to the regeneration system based on periodic intervals and / or transfer schedules, such as, for example, transferring the reforming catalyst after about 180 days, about 270 days, about 365 days, or later.

[0008] In some embodiments, the method involves regenerating the reforming catalyst by a regeneration process while passing through a regeneration system, and introducing the regenerated reforming catalyst into each top radial flow reactor of at least one reactor stack, or the top radial flow reactor of the first reactor stack, by inter-stack transfer, and then introducing the regenerated reforming catalyst into the top radial flow reactor via at least one purge chamber and at least one regenerated catalyst transfer system. In related aspects, the regenerated catalyst can be reduced by one or more of decoking, halogenation, oxychlorination, chlorination, fluorination (including, but not limited to, low-temperature fluorination), reduction, or combinations thereof, before or after transfer to the top of the at least one reactor stack. The reforming catalyst can be characterized by any physicochemical measurement or characteristic known to those skilled in the art, including, but not limited to, crush strength. Thus, in certain aspects, the reforming catalyst has a crush strength of about 15 pounds-force (lb). f ) less than 13 lbs f , or about 10 lbs. f Includes crushing strength.

[0009] In embodiments, the regeneration system of the disclosed method can be operated to provide for the transfer of reforming catalyst through a series of radial flow regeneration reactors, including passing the reforming catalyst through the regeneration system and returning to the stacked reactor system over a period of about one week via a regenerated catalyst transfer system. A further aspect is directed to the extraction of spent reforming catalyst via at least one purge vessel attached to the bottom of at least one reactor stack, where the spent reforming catalyst can be replaced with "replacement" reforming catalyst (in related embodiments, fresh catalyst, regenerated reforming catalyst, or a combination thereof) and re-added to at least one reactor stack via at least one purge vessel and at least one reduction vessel. The purge vessel can be operated to purge air and replace it with a reactive or inert gas atmosphere, such as a nitrogen or hydrogen atmosphere.

[0010] In further embodiments, the at least one reduction vessel can be operated to expose the catalyst to a reducing gas, such as hydrogen. In yet a further aspect, the regenerated catalyst is provided by transporting the spent reforming catalyst to a regenerator located in the same facility or in a separate regeneration facility and regenerating the catalyst. The catalyst can be regenerated continuously or batchwise, with batchwise regeneration generally associated with at least some aspects of the disclosed methodology, including embodiments associated with extracting spent reforming catalyst from at least one reactor stack and then regenerating the spent reforming catalyst. As noted in additional catalyst transfer processes and steps associated with the present technology, embodiments of the disclosed method involve transferring the reforming catalyst through at least one reactor stack to a purge vessel attached to the bottom of the at least one reactor stack for a period of at least about 180 days, about 270 days, about 365 days, or more than 365 days.

[0011] Embodiments of the disclosed methodology feature the reduction and / or elimination of components, features, processes, steps, etc. that may adversely reduce the effectiveness or lifespan of the catalyst. Thus, in some aspects, the internal components, surfaces, etc. of the regenerator are not coated with compositions that may poison the catalyst. This includes, but is not limited to, a metal protective layer containing tin (also referred to herein as MPT or tin-MPT). Furthermore, the stacked reactor system may further include a regenerator specifically adapted for storing spent catalyst, which may be regenerated when the amount of spent catalyst stored in the regenerator reaches a predetermined threshold amount. In yet further embodiments, the spent catalyst is removed from the regenerator when the amount of spent catalyst stored in the regenerator reaches a predetermined threshold amount and replaced with additional (replacement) catalyst, including fresh reforming catalyst. In a related aspect, the methodology further includes loading fresh reforming catalyst into a purge chamber and reduction vessel prior to the top reactor of the at least one reactor stack and reducing the fresh reforming catalyst prior to introducing it as a replacement catalyst into the top reactor of the at least one reactor stack.

[0012] The stacked reactor system may be configured in a myriad of arrangements to best practice the disclosed methodology, including embodiments in which the stacked reactor system is configured for one or more of these purposes, such as: 1) initially introducing the reforming catalyst into a purge tank connected to a reduction vessel connected to a top radial flow reactor of the at least one reactor stack; and / or 2) introducing a fresh hydrocarbon feed into the top radial flow reactor, thereby causing the reduced reforming catalyst and the hydrocarbon feed to flow co-directionally and simultaneously through the at least one reactor stack. In additional embodiments, the operating temperature of the top radial flow reactor is lower than the operating temperature of a radial flow reactor downstream of the top radial flow reactor, and the movement of the reforming catalyst through the at least one reactor stack occurs over a period of at least about 180 days, about 270 days, about 365 days, or more than 365 days.

[0013] Aspects related to the stacked reactor system may further include a configuration for introducing a fresh hydrocarbon feed into a bottom reactor of one of the at least one reactor stack, whereby the reforming catalyst and hydrocarbon feed flow in countercurrent through the at least one reactor stack, and movement of the reforming catalyst through the at least one reactor stack occurs over a period of at least about 180 days, about 270 days, about 365 days, or more than 365 days. In further embodiments, the operating temperature of each bottom reactor of the at least one reactor stack is lower than the operating temperature of its upper reactor, and each bottom reactor of the at least one reactor stack further functions as a guard bed to beneficially protect a downstream reactor of the one or more reactor stacks (containing a more active catalyst) from at least one undesirable compound, including, but not limited to, compounds that can poison the catalyst and / or reduce its effectiveness, such as sulfur, heavier components, nitrogen, or combinations thereof. Thus, aspects of the reforming reactor system associated with the disclosed methodology are advantageously associated with the lack of a need for incorporating or utilizing a sulfur conversion adsorber (SCA) upstream of the stacked reactor system, i.e., no SCA is present in the system.

[0014] In some aspects, the present disclosure relates to a reforming reactor system including a continuous catalyst regeneration (CCR) system including at least one reactor stack, each reactor stack including at least two radial flow reactors, each radial flow reactor including a reforming catalyst capable of catalyzing the conversion of hydrocarbons in a hydrocarbon feed to provide a reactor effluent including aromatic hydrocarbons, the reforming catalyst including a Group VIII metal, a zeolite support, and at least one halogen. In some aspects, the system may further include a regeneration reactor system connected to the at least one reactor stack via a spent catalyst transfer system and configured to regenerate the reforming catalyst. The reforming reactor system may be further configured to facilitate the transfer of the reforming catalyst through the at least one reactor stack for periods, including, but not limited to, at least about 180 days, about 270 days, about 365 days, or more than 365 days, in embodiments. Particular aspects of the system may include one or more of the following: 1) optionally coating one or more components of the reforming reactor system with tin MPT; and 2) incorporating a silica-bound L-zeolite support in the reforming catalyst with a catalyst (which may be present as an extrudate) characterized, in some embodiments, by a crush strength of less than about 15 lb-ft, about 13 lb-ft, or about 10 lb-ft. In a related aspect, at least one halogen of the reforming catalyst comprises fluorine, and the regeneration reactor system is operable to refluorinate any spent reforming catalyst received, for example, from a spent catalyst transfer system. In beneficial embodiments, the interior surfaces of the regeneration reactor and the reactor interiors of the regeneration reactor system can be operated in the absence of a protective coating; for example, the interior surfaces of the regeneration reactor and the reactor interiors of the regeneration reactor system need not be coated with a metallic protective layer, for example, tin MPT.

[0015] In some aspects, the CCR system is configured to introduce a reforming catalyst into at least one top reactor using a purge vessel and a reduction reactor, where the at least one top reactor is the top reactor of one of the at least one reactor stack. In related embodiments, the CCR system is configured to introduce a fresh hydrocarbon feed into the top reactor such that the reforming catalyst and the hydrocarbon feed flow simultaneously or co-directionally through the at least one reactor stack, and is further configured to promote movement of the reforming catalyst through the at least one reactor stack for a period of at least about 180 days, about 270 days, about 365 days, or more than 365 days. In further aspects, the CCR system can be configured to introduce a fresh hydrocarbon feed into the bottom radial flow reactor of one of the at least one reactor stack such that the reforming catalyst and the hydrocarbon feed flow countercurrently through the at least one reactor stack for a period of at least about 180 days, about 270 days, about 365 days, or more than 365 days. In additional embodiments, the bottom reactor of each of the at least one reactor stacks can function as a guard bed to protect a reactor downstream of the at least one reactor stack from at least one undesirable compound, including, but not limited to, sulfur, heavy components, nitrogen, or a combination thereof. Thus, the disclosed reforming reactor system can advantageously feature no sulfur conversion adsorber (SCA) located upstream of the CCR system.

[0016] In some embodiments, the disclosed system may include at least two reactor stacks and is configured to introduce a reforming catalyst into a top reactor of each of the at least two reactor stacks, spent catalyst is removed from a bottom reactor of each of the at least two reactor stacks, and a fresh hydrocarbon feed is introduced into and passes through the bottom reactor of one of the at least two reactor stacks, passes through the bottom reactor of a second reactor stack of the at least two reactor stacks, passes through the top reactor of a first reactor stack of the at least two reactor stacks, passes through the top reactor of the second reactor stack of the at least two reactor stacks, and passes sequentially through multiple reactors of each of the at least two reactor stacks until it passes through the top reactor of the second reactor stack of the at least two reactor stacks, from which reactor effluent is extracted. In an advantageous embodiment, the bottom reactor of each of the at least two reactor stacks can function as a guard bed to protect a downstream reactor in each of the at least two reactor stacks containing more active catalyst from at least one undesirable compound selected from, among others, sulfur, heavy components, nitrogen, and combinations thereof, thereby eliminating the need to place an SCA unit upstream of the CCR system.

[0017] Aspects of the present disclosure further relate to a method for operating a continuous catalyst regeneration (CCR) system comprising at least one stack of radial flow reactors, the process comprising continuously circulating a catalyst in a flow loop within the CCR system, regenerating the entire catalyst at least once a week, shutting down the CCR system to stop the conversion of convertible hydrocarbons to aromatic hydrocarbons, replacing the existing catalyst in the CCR system with a replacement catalyst comprised of platinum (Pt), fluoride (F), and / or chloride (Cl) on a silica-bound L-zeolite support, and starting the CCR to continue converting hydrocarbons in the hydrocarbon feed to aromatic hydrocarbons. In this case, the replacement catalyst is not continuously circulated in the flow loop within the CCR system. In a further embodiment, the replacement catalyst remains stationary within the CCR system during the conversion of hydrocarbons in the hydrocarbon feedstock to aromatic hydrocarbon products described herein, including hydrocarbons selected from hydrocarbons having no internal quaternary carbons with 6 or 7 carbon atoms and hydrocarbons having no two adjacent internal tertiary carbons with 6 carbon atoms. An additional aspect related to the operation of the reforming reactor system is to convert hydrocarbons in the hydrocarbon feed to the reforming catalyst until the reforming catalyst is determined to be a spent reforming catalyst, after which point the catalyst can be regenerated as described herein.

[0018] In some embodiments, the disclosed method of operating a continuous catalyst regeneration (CCR) system may further include ceasing the introduction of hydrocarbon feed after the catalyst is determined to be spent; purging the reactor until the reactor effluent contains less than about 200 ppm hydrocarbons; cooling the reactor to ambient temperature; removing spent reforming catalyst from the radial flow reactors of each reactor stack via inter-stack transfer, flowing the catalyst downward through at least one of the radial flow reactors of each reactor stack via the bottom radial flow reactor of each reactor stack or the bottom reactor of the final reactor stack; and adding fresh reforming catalyst via inter-stack transfer to the top of the top radial flow reactor of each reactor stack or the top radial flow reactor of the first reactor stack, wherein the fresh reforming catalyst flows downward through the stack of at least one radial flow reactor.

[0019] In a related aspect, the reforming reactor system further includes at least one purge chamber or lock hopper fluidly attached to the bottom radial flow reactor of each reactor stack or the bottom reactor of the final reactor stack, where transfer occurs between stacks, and where spent reforming catalyst is removed from the bottom radial flow reactor through the purge chamber prior to removing the catalyst from the stacked reactor system. In an embodiment, the method further includes purging the purge chamber with a gas comprising hydrogen, nitrogen, or both. In an additional embodiment, the reforming reactor system of the disclosed method includes a first purge chamber upstream and fluidly connected to a second purge chamber, and is operable or capable of purging the first purge chamber with a first purge gas and purging the second purge chamber with a second purge gas. In a related aspect, the first purge gas comprises hydrogen and the second purge gas comprises nitrogen, or alternatively, the first purge gas comprises hydrogen and the second purge gas comprises nitrogen. With respect to the reactor system of the present method, the stacked reactor system may be a purge chamber fluidly connected to the top radial flow reactor of each reactor stack, or the top reactor of the first reactor stack capable of inter-stack transfer or transport, for example, to add fresh reforming catalyst to the top radial flow reactor via the purge chamber, and optionally purged with a purge gas such as nitrogen.

[0020] Some aspects of the present disclosure relate to a continuous catalyst regeneration (CCR) system that includes operating a CCR system to convert hydrocarbons in a hydrocarbon feed to aromatic hydrocarbons, continuously circulating a catalyst in a flow loop within the CCR system, thereby regenerating the entire catalyst at least once a week, shutting down the CCR system to stop converting convertible hydrocarbons to aromatic hydrocarbons, replacing the existing catalyst in the CCR system with a replacement catalyst comprising Pt, F, and Cl on a silica-bound L-zeolite support, and starting up the CCR to continue converting variable hydrocarbons to aromatic hydrocarbons. In this case, the replacement catalyst may be intermittently circulated through the flow loop within the CCR system, thereby regenerating the entire catalyst no more than once a year. [Brief explanation of the drawings]

[0021] The following figures illustrate embodiments of the presently disclosed subject matter. The claimed subject matter can be understood by reference to the following description in conjunction with the accompanying figures, in which like reference numerals identify like elements unless otherwise stated and are described below.

[0022] [Figure 1] FIG. 1 is a flow diagram of a stacked reactor system used in an aromatization process according to one embodiment of the present disclosure. [Figure 2] FIG. 2 is a flow diagram of a stacked reactor system used in an aromatization process according to another embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0023] While exemplary implementations of one or more embodiments are provided below, it should be understood at the outset that the disclosed systems and / or methods may be implemented using any number of technologies, whether currently known or in existence. The disclosure should in no way be limited to the exemplary implementations, drawings, and technologies set forth below, but may be modified within the scope of the appended claims, including the exemplary designs and implementations shown and described herein, along with their full range of equivalents.

[0024] The present disclosure provides methods and systems relating to the operation of a reforming reactor system including at least one reactor stack. In embodiments, the reforming reactor system is an existing CCR (continuous catalyst regeneration) system previously operating to produce high-octane hydrocarbons by reforming with a reforming catalyst, and is reused as described herein to convert light naphtha to benzene, toluene, and xylenes (BTX) over an aromatization catalyst, which may include a zeolite support. While the conversion of a continuous catalyst regeneration reforming system is described in detail herein, it is contemplated that systems based on other reforming technologies, including semi-regenerative and periodic regeneration, may also be converted in accordance with the present disclosure and are intended to be within the scope of the present disclosure.

[0025] In the United States, demand for higher-octane hydrocarbons has declined significantly for a variety of reasons, including ethanol blending and declining gasoline demand. As a result, in some cases, reformer utilization rates have fallen to levels where they are no longer economically viable. Rather than shutting down such reforming units, they can be converted to chemical production in accordance with embodiments of the present disclosure. One of the most common reformer systems utilizes a continuous catalyst regeneration (or "CCR") process. CCR units traditionally operate via a constant catalyst flow through a stacked radial flow reactor to a regenerator; however, previously reported non-stacked radial flow reactors can be incorporated into the disclosed systems and methods in accordance with alternative aspects. In the regenerator, coke is burned to restore catalyst activity. Such catalyst regeneration is typically performed at least weekly. Such conventional CCR processes typically use four reactors, with heating between each reactor to provide the heat required for the endothermic reforming reaction(s). Because CCR operates in a moving bed, CCR catalysts are generally mechanically strong and often consist of platinum / alumina (Pt / Al2O3).

[0026] Aromatization (also referred to herein as "reforming") processes, such as the AROMAX® process, can be utilized to convert light naphtha to benzene and toluene via fixed-bed radial flow reactors. Similar to the CCR process, the hydrocarbons undergoing aromatization are heated as they pass from one reactor to the next to provide the endothermic heat of reaction. Aromatization catalysts (also referred to herein as reforming catalysts), such as the AROMAX® catalyst, can include Pt, Cl, and F supported on silica-bound L-zeolite. The typical run length of an aromatization catalyst, such as the AROMAX® catalyst, can be about 1.5 to 2.5 years, after which the catalyst is removed and disposed of or regenerated. This turnaround can be quite costly due to both downtime and other expenses.

[0027] In conventional fixed-bed radial flow aromatization reactor designs, the catalyst near the center tube is often underutilized due to endothermic reactions that cool the feed from the outside to the inside of the aromatization reactor. Thus, even when catalysts installed inside a fixed-bed radial flow reactor are discarded at the end of a run, they usually still have some useful life remaining.

[0028] It has been unexpectedly discovered that stacked reactors designed for moving-bed operation, such as CCR systems, can be used for the aromatization of hydrocarbons via aromatization catalysts, such as AROMAX® catalysts. Although described herein with respect to AROMAX® catalysts, the systems and methods of the present disclosure may be suitable for use with other aromatization catalysts that are generally considered too weak for use in moving-bed reactor systems (e.g., having too low a crush strength, as further described herein), and the use of such catalysts with the systems and methods disclosed herein is intended to be within the scope of the present disclosure.

[0029] The difference between the CCR process and the AROMAX® process is the catalyst regeneration step. In the CCR process, the catalyst flows down through a stacked reactor system to a regenerator, where it is typically exposed to oxygen for coke burnout, chlorine for platinum redispersion, and hydrogen for reduction before being returned to the stacked reactor system. The catalyst can be transferred to the regenerator fairly quickly; the catalyst can be passed through there approximately once a week. In contrast, the AROMAX® catalyst is not expected to be significantly regenerated by coke burnout and platinum redispersion alone, even once a week or once a month. Three configurations are provided herein for utilizing CCR or stacked reactor setups (either existing or conventional designs) with the AROMAX® catalyst. A first variation involves operating the radial flow reactor of the stacked reactor system as a stationary fixed bed, a second variation involves moving the catalyst to a downstream regeneration system and reintroducing the regenerated catalyst into the stacked reactor and operating the radial flow reactor of the stacked reactor system, and a third variation involves operating the radial flow reactor in the stacked reactor system without moving the catalyst to a downstream regeneration system and without reintroducing the catalyst into the stacked reactor.

[0030]

[0009] Provided are aspects relating to a method of operating a reforming reactor system including at least one reactor stack, as shown in Figure 1, where each reactor stack includes at least two stacked radial flow reactors, each radial flow reactor including a reforming catalyst capable of catalyzing the conversion of hydrocarbons in a hydrocarbon feed to provide a reactor effluent including aromatic hydrocarbons. In embodiments, the reforming catalyst includes a Group VIII metal, a zeolite support, and at least one halogen. In embodiments, the reforming reactor system includes a continuous catalyst regeneration (CCR) system retrofitted and / or operated with the aromatization catalyst described herein.

[0031] An embodiment relating to a reforming system and process according to the present disclosure will be described with reference to FIG. 1. FIG. 1 is a flow diagram of a stacked reactor system 100 for use in an aromatization process according to an embodiment of the present disclosure. The reforming reactor system of the present disclosure includes at least one reforming reactor stack. The stacked reactor system 100 includes two stacks of reforming reactors: a first stack of reforming reactors S1 and a second stack of reforming reactors S2. The reforming reactor system according to the present disclosure may further include a heat transfer device configured to heat the effluent of one reforming reactor before introducing it into a downstream reactor. The system 100 includes a heat exchanger 120A and a heat exchanger 120B. In an embodiment, the first heat exchanger 120A and the second heat exchanger 120B are a single heat exchanger.

[0032] The reforming reactor system of the present disclosure may further include an inter-stack transfer line operable for transferring reforming catalyst between reactor stacks of a multi-stack system. The stacked reactor system 100 includes an inter-stack transfer line 134. Valve V1 may be operable to control the flow of catalyst from the first reactor stack S1. The reforming reactor system of the present disclosure may further include one or more vessels operable as lock hoppers, purge vessels, and / or reduction vessels attached to and / or fluidly connected to the lowest reactor of each reactor stack, or a vessel attached to and / or fluidly connected to the lowest reactor of the last stack in a system including a series (i.e., multiple) of reactors with inter-stack transfers. The stacked reactor system 100 includes a vessel 150A fluidly connected to the lowest reactor (i.e., the fourth reforming reactor 110D) of the last reactor stack (i.e., the second reactor stack S2).

[0033] The reforming reactor system of the present disclosure may further include one or more vessels operable as purge vessels and / or reduction vessels attached to and / or fluidly connected to the top reforming reactor of each reactor stack, or attached to and / or fluidly connected to the top reactor of a first stack in a system including a series (i.e., multiple) stacks with transfers between stacks. The stacked reactor system 100 includes a vessel 150B fluidly connected to the top reactor (i.e., first reforming reactor 110A) of the first reactor stack (i.e., first reactor stack S1).

[0034] The reforming reactor system of the present disclosure may further include a spent catalyst transport line (also referred to herein as a "spent" catalyst transport line) configured to transport spent catalyst exiting the reforming reactor stack(s) to a downstream unit, such as a catalyst regenerator or storage vessel. The stacked reactor system 100 includes a spent catalyst transport line 135. The reforming reactor system of the present disclosure may further include a downstream unit, such as a catalyst regenerator or storage vessel. The stacked reactor system 100 includes a downstream unit 140. The spent catalyst transport line 135 may fluidly connect the last stack of the stacked reactor system to the downstream unit 140, optionally via vessel(s) 150A. One or more valves V2 may be operable to control the flow of catalyst from the second reactor stack S2. Although valve V2 is shown upstream of vessel 150A, in embodiments, valve V2 may be located upstream or downstream of vessel 150A. The stacked reactor system 100 may include a make-up catalyst introduction line 130 and a valve V4 operable to control the amount of make-up catalyst introduced thereby to the downstream unit 140.

[0035] The reforming reactor system according to the present disclosure further includes a replacement catalyst transport line or conveying system configured to transport catalyst (regenerated catalyst, fresh catalyst, make-up catalyst, or a combination thereof, various embodiments are contemplated) from a downstream unit to the top reforming reactor of each reactor stack, or to the top reactor of the first reactor stack in a system including a series (i.e., multiple) reactor stacks with transport between stacks, optionally via one or more reduction vessels, purge vessels, and / or lock hoppers. For example, in embodiments, an existing CCR is being repurposed for use with aromatization (e.g., AROMAX® catalyst). Such a CCR system may include a catalyst transfer line that continuously circulates the catalyst throughout the system during operation. The stacked reactor system 100 includes a replacement catalyst transport line or conveying system 131 configured to transport catalyst from the downstream unit 140 to the first or top reforming reactor 110A in the first reactor stack S1. Replacement catalyst delivery system 131 may be operable to introduce catalyst into top reactor 110A via inter-stack transfer to the top radial flow reactor of each reactor stack, or via vessel 150B fluidly connected to the top reactor of the first reactor stack. Vessel 150B may include a purge chamber. A purge line or "catalyst dump" line 132 may be fluidly connected to replacement catalyst delivery system 131 via valve V3 and is operable to control the flow of catalyst out of system 100 via catalyst purge line 132.

[0036] The reforming reactor system of the present disclosure may further include several valves configured to direct the flow of catalyst throughout the system, as discussed further herein. The stacked reactor system 100 of FIG. 1 includes valves V1, V2, V3, and V4. The valves shown in FIG. 1 and described herein are used as a tool to illustrate flow paths and are not intended to limit the disclosure to a particular operating procedure or equipment setup. The aforementioned components of a reforming reactor system according to the present disclosure are described in more detail herein.

[0037] A hydrocarbon feed containing hydrocarbons to be converted to aromatic hydrocarbons is introduced into the first heat exchanger 120A via hydrocarbon feed line 105, where the temperature of the hydrocarbon feed is raised to the desired first reforming reactor inlet temperature. From the first heat exchanger 120A, the heated hydrocarbon feed is introduced into the first or "top" reforming reactor 110A of the first reactor stack S1 via first reactor inlet line 106.

[0038] The hydrocarbon feed, in some embodiments, includes both convertible and non-convertible hydrocarbons, including at least about 96% by weight of C6-C8 hydrocarbons and up to about 4% of C9 or higher hydrocarbons. As used herein, "convertible" hydrocarbons include hydrocarbons having 6 or 7 carbon atoms with no internal quaternary carbons and hydrocarbons having 6 carbon atoms with no two adjacent internal tertiary carbons. Such convertible hydrocarbons may include methylpentane, methylhexane, dimethylpentane, and mixtures thereof. Convertible components may include 2-methylpentane, 3-methylpentane, 2,4-dimethylpentane, 2,3-dimethylpentane, n-hexane, 2-methylhexane, 3-methylhexane, n-heptane, and mixtures thereof. As used herein, "non-convertible" hydrocarbons include highly branched hydrocarbons containing 6 or 7 carbon atoms and an internal quaternary carbon, and hydrocarbons having 6 carbon atoms and two adjacent tertiary carbons. Highly branched hydrocarbons include dimethylbutane (DMB), trimethylbutane, dimethylpentane, and mixtures thereof. Highly branched hydrocarbons having 6 or 7 carbon atoms and an internal quaternary carbon may include, for example, 2,2-dimethylbutane, 2,2-dimethylpentane, 3,3-dimethylpentane, 2,2,3-trimethylbutane, and combinations thereof. Highly branched hydrocarbons having 6 carbon atoms and an adjacent internal tertiary carbon atom may include 2,3-dimethylbutane. Highly branched hydrocarbons do not readily convert to aromatic products and instead tend to convert to light hydrocarbons. As used herein, "unreacted" hydrocarbons refer to convertible hydrocarbons that have passed through the reforming reactor stack without being converted to aromatic hydrocarbons.

[0039] In the first / top reforming reactor 110A, convertible hydrocarbons in the hydrocarbon feed are converted (or partially converted) to reformed products containing BTX through contact with a catalytic reforming catalyst and under the operating conditions described herein. An effluent containing aromatic hydrocarbons is removed from the first reforming reactor 110A via a first reactor effluent line 107. The first reactor effluent is introduced via the first reactor effluent line 107 into a first heat exchanger 120A, where it is heated to the desired downstream reforming reactor inlet temperature. The heated first reactor effluent is introduced from the first heat exchanger 120A into the second reforming reactor 110B via a second reforming reactor inlet line 108. In the second reforming reactor 110B, the convertible hydrocarbons are converted to reformed products containing BTX through contact with an aromatization catalyst under the operating conditions described herein. Effluent containing aromatic hydrocarbons is removed from the second reforming reactor 110B via second reforming reactor effluent line 109. The second reactor effluent is introduced via first reactor effluent line 109 to a first heat exchanger 120A where it is heated to the desired downstream reforming reactor inlet temperature. The heated second reactor effluent is introduced via the first heat exchanger 120A and optionally a second heat exchanger 120B (which may be introduced via an interstack hydrocarbon transfer line 116A that transports hydrocarbons between the first reactor stack S1 and the second reactor stack S2) to the third or "top" reforming reactor 110C of the second reactor stack S2 via a third reforming reactor inlet line 116B.

[0040] In the third reforming reactor 110C, the convertible hydrocarbons are contacted with a catalytic reforming catalyst and under the operating conditions described herein, where the aromatic hydrocarbons are converted to reformed products comprising BTX. An effluent comprising aromatic hydrocarbons is removed from the second reforming reactor 110C via a third reforming reactor effluent line 117. The third reactor effluent is introduced via the third reforming reactor effluent line 117 into the second heat exchanger 120B, where it is heated to the desired downstream reforming reactor inlet temperature. The heated third reactor effluent is introduced from the second heat exchanger 120B into the fourth reforming reactor 110D via a fourth reforming reactor inlet line 118. In the fourth reforming reactor 110D, the convertible hydrocarbons are contacted with a catalytic reforming catalyst and under the operating conditions described herein, where the aromatic hydrocarbons are converted to reformed products comprising BTX. Effluent containing aromatic hydrocarbons is removed from the fourth or bottom reforming reactor 110D of the second reactor stack S2 via fourth reforming reactor effluent or "hydrocarbon product" outlet line 125.

[0041] The reforming reactor system 100 includes a first reactor stack S1, which includes a first reforming reactor 110A and a second reforming reactor 110B, respectively. The first reforming reactor 110A is the top reforming reactor of the first reactor stack S1 and is disposed above the second reforming reactor 110B, which is the bottom reforming reactor of the first reactor stack S1. The third reforming reactor 110C is the top reforming reactor of the second reactor stack S2 and is disposed above the fourth reforming reactor 110D, which is the bottom reforming reactor of the second reactor stack S2. The reforming reactor system of the present disclosure can include a single stack or multiple stacks, including, but not limited to, two, three, or four reactor stacks. In embodiments, such as the embodiment of FIG. 1, a hydrocarbon feed is transported between the reactor stacks. In embodiments, a reforming catalyst is transported between the reactor stacks. In embodiments, both a hydrocarbon feed and a reforming catalyst are transported between the reactor stacks.

[0042] The reforming reactor system disclosed herein includes a stack of reforming reactors. As commonly understood, a reforming "reaction" typically occurs in a reforming "reactor." The reforming reactor used in the systems and methods described herein can be any conventional type of reactor capable of maintaining a catalyst within the reactor and accommodating a continuous flow of hydrocarbons. The catalytic reactor systems described herein can include fixed catalyst bed systems, moving catalyst bed systems, fluidized catalyst bed systems, or combinations thereof. Suitable reactors include, but are not limited to, fixed bed reactors such as radial flow reactors, bubbling bed reactors, and ebullated bed reactors. The feed stream can pass upward, downward, or radially through the reactor(s). In various embodiments, the catalytic reactor systems described herein can be operated as adiabatic or isothermal catalytic reactor systems. As used herein, a "hydrocarbon stream" includes hydrocarbons, but components other than hydrogen and carbon-containing molecules can be present in the stream (e.g., hydrogen gas). In some embodiments, "hydrocarbon" can include individual molecules that contain one or more atoms other than hydrogen and carbon (eg, nitrogen, oxygen, etc.).

[0043] In embodiments, the reforming reactor is a radial flow reactor in which the hydrocarbon flow passes inward or outward through the reactor. The reactors may be sized according to known techniques, and all reactors may be the same size. Alternatively, one or more reactors may be different sizes. For example, in embodiments, the reforming reactor system, as described herein, includes a CCR that has been modified and / or repurposed for use with the aromatization catalyst described herein. In embodiments, the reactor stack may increase in size (i.e., volume) from the top reactor to the bottom reactor. For example, in embodiments, a two-reactor stack may include a first reactor, or top reactor, with 30%, 40%, or 50% catalyst volume and a second reactor, or bottom reactor, with 50%, 60%, or 70% catalyst volume, where the total catalyst volume of all reforming reactors in the stack is 100%. In an alternative embodiment, a three reactor stack may include a first or top reactor with 10%, 20%, or 30% catalyst volume, a second or middle reactor of the stack with 20%, 30%, or 40% catalyst volume, and a third or bottom reactor of the stack with 30%, 40%, or 50% catalyst volume. In an alternative embodiment, a four reactor stack may include a first or top reactor of the stack with 10%, 20%, or 30% catalyst volume, a second reactor of the stack with 20%, 30%, or 40% catalyst volume, a third reactor of the stack with 20%, 30%, or 40% catalyst volume, and a fourth or bottom reactor of the stack with 30%, 40%, or 50% catalyst volume.

[0044] In an embodiment, the multi-stack system includes two stacks that transport a catalyst between the stacks, and each stack includes two reforming reactors. In some such embodiments, the volume percentage of the total reforming catalyst in the first reactor (the uppermost reactor in the first reactor stack) (equivalent to taking the total volume of the catalyst in all the reforming reactors of the reforming reactor system as 100%) is a volume of about 10% to about 30%, the volume percentage of the catalyst in the second reactor (the lowermost reactor in the first reactor stack) is a volume percentage of about 10% to about 30%, the volume percentage of the catalyst in the third reactor (the uppermost reactor in the second reactor stack) is a volume percentage of about 10% to about 30%, and the volume percentage of the catalyst in the fourth reactor (the lowermost reactor in the second reactor stack) is a volume percentage of about 10% to about 30%.

[0045] In an embodiment, the multi-stack system includes two stacks that transport a catalyst between the stacks, and each stack includes three reforming reactors. In some such embodiments, the volume percentage of the total reforming catalyst in the first reactor (the uppermost reactor in the first reactor stack) (considering the total volume of the catalyst in all the reforming reactors of the reforming reactor system as 100%) is about 10 to about 30%, the second reactor (the middle reactor of the first reactor) is about 10 to about 30%, the volume ratio of the catalyst in the third reactor (the lowermost reactor of the first reactor) is about 10 to about 30%, the volume ratio of the catalyst in the fourth reactor (the uppermost reactor of the second reactor) is between about 10% and about 30%, the volume ratio of the catalyst in the fifth reactor (the middle reactor of the second reactor stack) is between about 10% and about 30%, and the volume ratio of the catalyst in the sixth reactor (the lowermost reactor of the second reactor stack) is between about 10% and about 30%.

[0046] Under catalytic conditions, the activity of the catalyst decreases with the passage of reaction time and becomes a "spent" catalyst. That is, if the activity of the new catalyst is x, the activity of the spent catalyst is y, and x is greater than y. In one embodiment, by reactivating the spent catalyst, the catalytic activity of the spent catalyst increases, and a catalytic activity z is obtained. Here, z is greater than y but smaller than x (y < z < x). The method of restoring the activity to the spent catalyst will be described in more detail later in this specification. Variant 1: Operation of the reforming reactor as a stationary radial fixed bed

[0047] In the reforming reactor, the hydrocarbon feed is contacted with a reforming catalyst. In a first variant of the reforming method according to the present disclosure, the stacked reactors are operated as stationary fixed beds, and the reforming catalyst remains fixed during aromatization of the hydrocarbon feed. In such an embodiment, the reforming catalyst does not move during operation. The stacked reactor system may be configured so that the reforming catalyst is first introduced into one or more vessels 150B operable as purge tanks or reduction vessels connected to at least one uppermost radial flow reactor of at least one reactor stack. This allows the catalyst to be stored and / or reduced therein before being introduced into the first reactor stack S1.

[0048] The reforming reactor system can be operated to convert convertible hydrocarbons in the hydrocarbon feed until the reforming catalyst is determined to be "spent" reforming catalyst. According to an embodiment of Variant 1, the reforming catalyst does not move at all during a run, with the reactor operating as a stationary radial flow fixed bed. In such an embodiment, valves V1-V4 in FIG. 1 can be closed during a run. In this manner, the CCR system can be operated similarly to a conventional AROMAX® process, i.e., using a stationary fixed bed radial flow reactor. According to Variant 1, an existing CCR can be utilized for aromatization, in an embodiment, without utilizing the moving bed or catalyst regeneration capabilities of a conventional CCR process.

[0049] A catalyst may be deemed spent as is known in the art. For example, a catalyst may be deemed spent if the outlet temperature of the final or fourth reforming reactor 110D increases, e.g., equal to or greater than a threshold temperature indicating a sufficient level of catalyst deactivation to warrant catalyst replacement. In another example, a catalyst may be deemed spent if the selectivity for desired aromatic compounds in the final or fourth reforming reactor 110D decreases, e.g., equal to or less than a threshold selectivity indicating a sufficient level of catalyst selectivity loss to warrant catalyst replacement. In an embodiment, when a radial flow reactor is used as a stationary fixed bed, the spent catalyst extracted via the spent catalyst transfer line 135 has an activity of about 90%, about 80%, about 70%, about 50%, and about 25% or less of the optimal activity of the fresh catalyst. When a catalyst is deemed spent, the introduction of the hydrocarbon feed is stopped. The reforming reactors can be purged, for example, until the reforming reactor effluent (e.g., product extracted from the fourth reforming reactor 110D via product discharge line 125) contains about 200 ppm, about 100 ppm, about 50 ppm, or less than about 50 ppm hydrocarbons. The reforming reactors can be heated to ambient temperature and / or cooled to ambient temperature, which can be about 60°C or less, about 50°C or less, about 40°C or less, about 30°C or less, and about 25°C or less, depending on the geographic location, altitude, and other factors known to those skilled in the art. Once the desired temperature is reached, the spent reforming catalyst can be removed from the radial flow reactors in each reactor stack via an inter-stack transfer, either through the bottom radial flow reactor of each reactor stack or the bottom reactor of the final reactor stack, with the catalyst flowing downward through at least one radial flow reactor stack. For example, spent reforming catalyst may be removed from the fourth reactor 110D. In one embodiment, the catalyst is removed or discharged from the fourth reactor 110D via catalyst transfer line 135, followed by the third reactor 110C, the second reactor 110B (via interstack transfer line 134), and the first reactor 110A (via interstack transfer line 134).Fresh reforming catalyst can be introduced into the top of the top radial flow reactor of each reactor or into the top radial flow reactor of the first reactor via interstack transfer and flow downward through at least one stack of radial flow reactors. For example, in the embodiment of FIG. 1, fresh catalyst can be introduced via transfer line 131, lock hopper and / or reduction vessel 150B, and first reforming reactor 110A. In one embodiment, catalyst is added or charged via transfer line 131 to fourth reactor 110D (via interstack transfer line 134), then to third reactor 110C (via interstack transfer line 134), second reactor 110B, and first reactor 110A, in that order.

[0050] Spent reforming catalyst can be removed from the stacked reactor system by inter-stack transfer through a purge chamber or lock hopper fluidly attached to the bottom radial flow reactor of each reactor stack or the bottom reactor of the final reactor stack. For example, in the embodiment of Figure 1, the spent catalyst can be removed after passing through vessel 150A, which is a purge vessel or lock hopper.

[0051] The spent catalyst in purge chamber 150A may be purged with a gas comprising hydrogen or nitrogen. In an embodiment, vessel(s) 150A includes first and second purge chambers fluidly connected in series. In such an embodiment, the first purge chamber may be purged with a first purge gas and the second purge chamber may be purged with a second purge gas. The first purge gas may comprise hydrogen and the second purge gas may comprise nitrogen, or the first purge gas may comprise hydrogen and the second purge gas may comprise nitrogen.

[0052] Fresh reforming catalyst may be added to the top radial flow reactor via vessel 150B, which may be a purge chamber, lock hopper, reduction vessel, or one or more vessels operable to purge, store, and / or reduce fresh catalyst prior to introduction into the first reforming reactor 110A.

[0053] In an embodiment, the fresh reforming catalyst is contacted with a purge gas in purge chamber 150B before it is introduced into the top radial flow reforming reactor. In an embodiment, the purge gas comprises nitrogen. Variant 2: Operation with slow catalyst movement through stacked reactors to the regenerator

[0054] In a second variant of the reforming method according to the present disclosure, the radially stacked reactors are not operated as stationary fixed beds, but are operated to transfer the reforming catalyst through at least one reactor stack (e.g., S1 and / or S2) via a spent or spent catalyst transfer system to a downstream unit including a regeneration system where the spent catalyst is regenerated. In embodiments, the stacked reactor system is operable to transfer the reforming catalyst through at least one reactor stack for a period of at least about 180 days, about 200 days, about 250 days, about 270 days, about 300 days, about 325 days, about 350 days, about 360 days, about 365 days, or more than 365 days. In embodiments, the catalyst moves very slowly to the regeneration section. The catalyst placed in the regenerator can be regenerated, for example, by coke combustion (e.g., contact with chlorine and oxygen), redispersion of metals (e.g., platinum), and halogenation (e.g., fluorine for refluorination), as described in more detail below. The regenerated catalyst may then be returned to the stacked reforming reactor section.

[0055] Although sometimes referred to as spent or "spent" catalyst, the catalyst removed via spent catalyst transfer line 135 may still retain significant catalytic activity. In embodiments, when operating a radial flow reactor with continuous catalyst transfer (via the second or third variant described herein), the spent catalyst extracted via spent catalyst transfer line 135 has an activity y that is no more than about 90%, about 80%, about 70%, about 50%, about 10%, or about 5% percent of the activity "x" of the fresh catalyst. In certain embodiments, catalysts with up to about 50%, about 80%, and about 95% reduced catalytic activity may be discarded first.

[0056] In embodiments, the reforming methods disclosed herein include extracting and replacing spent reforming catalyst with a replacement catalyst, wherein the spent reforming catalyst may be transferred between stacks through at least one purge vessel attached to or fluidly connected to the bottom reforming reactor of each reactor stack or the bottom reforming reactor of the final reactor stack, and the replacement catalyst may be transferred between stacks back to the top reforming reactor of each reactor stack or the top reforming reactor of the first reactor stack and may be transferred through at least one purge vessel and / or at least one reduction vessel before being introduced into the top reactor.

[0057] The stacked reactor system 100 includes a spent or "spent" catalyst transport line or conveyance system 135. Spent or spent catalyst may be removed from the fourth reactor 110D, the last or bottom reactor of the second reactor group S2, via the spent or "spent" catalyst transport line or conveyance system 135. The spent or spent catalyst may pass through one or more vessels 150A before being conveyed to the downstream unit 140.

[0058] In an embodiment, the catalyst transfer system transfers the reforming catalyst via inter-stack transfer through at least one purge chamber or lock hopper attached to the bottom radial flow reactor of each of the at least one reactor stack or the final bottom radial flow reactor of the at least one reactor stack. The spent catalyst transfer system 135 can be operated to transfer catalyst from the bottom radial flow reforming reactor 110D through the purge vessel or lock hopper 150A. The vessel 150A can be integral with the fourth reforming reactor 110D or can be connected thereto via the spent catalyst transfer system 135, as shown in the embodiment of FIG. 1. In an embodiment, the movement of the reforming catalyst through the at least one reactor stack to the purge vessel or lock hopper 150A occurs over a period of at least about 180 days, about 270 days, about 365 days, or more than 365 days.

[0059] The spent catalyst conveying system 135 may have at least one purge chamber 150A fluidly connected to the top of the regeneration system 140. The spent catalyst conveying system 135 may be operated to transport the catalyst using pneumatic or non-pneumatic methods, including, but not limited to, methods using one or more of a conveyor belt, a screw, a shuttle hopper, a supersack, and a pneumatic method using one or more of air, hydrogen, nitrogen, argon, and additional inert or non-inert commercial gases. The spent reforming catalyst may be moved through the conveying system 135 to the regeneration system 140 continuously, intermittently, or batchwise. In an embodiment, the extraction of the spent reforming catalyst from at least one reactor stack (e.g., S1 and / or S2) and the regeneration of the spent reforming catalyst in the regeneration system 140 are performed in a batch process.

[0060] In an embodiment, the reforming catalyst in at least one stack of the radial flow reactors (e.g., S1 and / or S2) is transferred to a regeneration system about every 180 days, about every 270 days, about every 365 days, or more than every 365 days via a spent catalyst transport system 135. The spent catalyst introduced into the regenerator 140 continuously, semi-continuously, or batchwise can be regenerated therein when the amount of spent catalyst stored in the regenerator reaches a predetermined threshold amount.

[0061] As described herein, according to this second variant, the downstream unit 140 includes a regenerator or regeneration system operable to regenerate the spent catalyst. Upon regeneration, the catalytic activity of the spent catalyst introduced into the regeneration system 140 via the spent catalyst transfer line 135 may be increased by reactivating the spent catalyst to a catalytic activity z, where z is greater than y (the activity of the spent catalyst) but less than the activity "x" of the fresh catalyst (y <z<x)。

[0062] In embodiments, the interior of the regenerator is not coated with a metallic protective layer containing tin, also referred to as tin MPT. While tin MPT coatings can be beneficial in some systems and methods, for example, to prevent carburization of process components and / or vessels, their presence in the regenerator can have the adverse effect of varying degrees of catalyst poisoning. In embodiments, the interior surface of the regeneration reactor and / or the reactor interior of the regenerator is not coated with tin MPT. In embodiments, the interior surface of the regeneration reactor and / or the reactor interior of the regenerator is coated with tin MPT.

[0063] In an embodiment, the spent aromatization catalyst introduced into the regeneration system or regenerator 140 is regenerated by any method known to those skilled in the art. The material(s) utilized to regenerate the spent catalyst are introduced into the regeneration system or vessel(s) 140 via line(s) 141. The regeneration exhaust gas may be removed from the regeneration vessel(s) or system 140 via regeneration exhaust gas outlet line(s) 142. In an embodiment, the regeneration process includes decoking, halogenation, reduction, or a combination thereof. In an embodiment, the aromatization catalyst includes a catalyst support, one or more catalytically active metals, and at least one halide. In an embodiment, the aromatization catalyst includes a catalyst support, one or more catalytically active metals, and at least two halides. In an embodiment, the reforming catalyst includes a Group VIII metal, a zeolite support, and at least one halogen. In an embodiment, the at least one halogen includes fluorine, and the regenerator is operable to refluorinate the spent reforming catalyst. Such aromatization catalysts are described in further detail herein.

[0064] In embodiments, regeneration involves reducing the amount of carbonaceous material contained in the spent catalyst, redispersing metals on the catalyst support, and reactivating the catalyst to restore at least a portion of its catalytic activity. In embodiments, the regeneration process includes decoking, oxychlorination, fluorination, reduction, or a combination thereof. Such regeneration methods are described, by way of non-limiting example, in U.S. Pat. Nos. 8,664,144 and 9,421,529, the disclosures of each of which are incorporated herein in their entirety for all purposes not inconsistent with this disclosure.

[0065] In embodiments, the regeneration process includes chlorination, decoking, fluorination, reduction, or a combination thereof. These regeneration methods are described, by way of non-limiting example, in U.S. Patent App. Ser. (U.S. Patent Application Serial No.) 14 / 230,373, U.S. Patent No. 8,716,161, U.S. Patent No. 8,912,108, U.S. Patent No. 9,174,895, and U.S. Patent No. 9,421,530, each of which is incorporated herein by reference. In embodiments, the fluorination includes low-temperature fluorination. Such regeneration methods are described, by way of non-limiting example, in U.S. Patent No. 10,300,476, the disclosure of which is incorporated herein in its entirety.

[0066] In an embodiment, the spent catalyst is first contacted with chlorine and oxygen to burn off the coke and redisperse the platinum. Regeneration may further include the addition of fluorine. Regenerated catalyst

[0067] As described above, regenerating a spent catalyst may include reducing the amount of carbonaceous material present in the spent catalyst. Regeneration may further include redispersing metals around the catalyst support. The metals may be redispersed by contact with one or more redispersing compounds. The metals may be redispersed at the periphery of the catalyst, in one or more layers (e.g., skin layers) of the catalyst, throughout the catalyst, or various combinations thereof, and such distribution may be uniform or non-uniform. The metals of the catalyst support may then be reactivated by contacting the material with a reactivation composition. The reactivation composition may include one or more halides. Regeneration may further include heat treating the composition. Although the decoking, redispersion, and reactivation steps are described herein in a specific order, the order of these steps may be varied in accordance with the U.S. patents described and incorporated by reference herein.

[0068] Reducing the amount of carbonaceous material associated with a catalyst can be called decoking. Decoking is a process of converting carbonaceous materials into carbon monoxide and water, and involves heating the spent catalyst at about 25°C to about 1000°C, or about 50°C to about 900°C, or about 100°C to about 800°C, or 200°C to 700°C, or 300°C to 600°C to produce a decoked spent catalyst. Decoking can be performed by heating the spent catalyst for about 1 hour to about 40 hours, or about 2 hours to about 25 hours, or about 3 hours to about 20 hours, or about 4 hours to about 15 hours, or about 5 hours to about 10 hours to produce a decoked spent catalyst. The decoking process may be carried out by heating the spent catalyst in the presence of oxygen, at an oxygen concentration of from about 0.01 mol % to about 20 mol %, alternatively from about 0.1 mol % to about 15 mol %, alternatively from about 0.2 mol % to about 10 mol %, alternatively from 0.5 mol % to 5 mol %, alternatively from 1 mol % to 3 mol % to produce a decoked spent catalyst.

[0069] Regeneration can include redispersing the metals on the catalyst support. In embodiments, the metals on the decoked spent catalyst are redispersed on the catalyst support after decoking the spent catalyst. Without wishing to be bound by theory, the aforementioned decoking process and / or the hydrocarbon conversion process to which the spent catalyst is subjected can adversely lead to agglomeration of the metals on the catalyst support. The agglomerated metals are physically and chemically less available for catalytic reaction and therefore must be redispersed to fully restore catalytic activity. In embodiments, the metals on the spent catalyst (which may now be a decoked catalyst) are redispersed via several processes commonly referred to as oxychlorination. Oxychlorination of the spent catalyst can be carried out by contacting the catalyst with a redispersion composition of the type and under conditions described herein.

[0070] In one embodiment, the spent catalyst is contacted with a redispersion composition comprising a chlorine-containing compound and oxygen. The chlorine-containing compound can be in a solid phase, liquid phase, gas phase, or a combination thereof. Examples of chlorine-containing compounds suitable for use in the redispersion composition include, but are not limited to, hydrochloric acid, chlorine, carbon tetrachloride, tetrachloroethylene, chlorobenzene, methyl chloride, methylene chloride, chloroform, allyl chloride, trichloroethylene, chloramine, chlorine oxide, chloric acid, and chlorine. Examples include, but are not limited to, carbon dioxide, dichlorine monoxide, heptoxide dichlorine, hydrochloric acid, perchloric acid, or a combination thereof.

[0071] The contact of the spent catalyst with the redispersion composition can be carried out at a temperature ranging from about 25°C to about 1000°C, alternatively from about 50°C to about 900°C, alternatively from about 100°C to about 800°C, alternatively from about 200°C to about 400°C, alternatively from about 400°C to about 600°C, for a period of about 0.5 hours to about 50 hours, alternatively from about 1 hour to about 20 hours, or alternatively from about 2 hours to about 10 hours. The contact of the spent catalyst with the redispersion composition can be carried out in the presence of oxygen. When oxygen is used, the oxygen concentration used is between about 0.01 mol% and about 20 mol%, alternatively from about 1 mol% to about 18 mol%, alternatively from about 5 mol% to about 15 mol%, or alternatively from about 8 mol% to about 12 mol%.

[0072] In an alternative embodiment, the spent catalyst is contacted with a redispersion composition comprising a chlorine-containing compound (e.g., HCl) of the type described herein and oxygen in the presence of water. When water is used, the molar ratio of water to hydrochloric acid (HO:HCl) can range from about 0.01:1 to about 10:1, alternatively from about 0.5:1 to about 5:1, alternatively from about 1:1 to about 3:1. When a chlorine-containing compound other than hydrochloric acid is used, the molar ratio of HO:HCl is calculated based on the equivalent amount of hydrochloric acid produced in the presence of the spent catalyst.

[0073] In one embodiment, a weak base may be added during metal redispersion to neutralize any free acid that may be present. An example of a weak base suitable for use in the present disclosure includes, but is not limited to, ethylenediamine (EDA). The resulting material is a redispersed spent catalyst, which may be further dried under suitable conditions. Additionally, or alternatively, the spent catalyst (e.g., a decoked and / or redispersed spent catalyst) may be calcined at a temperature ranging from about 25°C to about 1000°C, alternatively from about 50°C to about 900°C, alternatively from about 100°C to about 800°C, alternatively from about 200°C to about 700°C, or alternatively from about 300°C to about 600°C. Calcination may be performed for a period of about 1 hour to about 40 hours, alternatively from about 2 hours to about 25 hours, alternatively from about 3 hours to about 20 hours, alternatively from about 4 hours to about 15 hours, alternatively from about 4 hours to about 15 hours, or alternatively from about 5 hours to about 10 hours. The calcination step may be carried out by heating the spent catalyst in the presence of oxygen, wherein the oxygen concentration is from about 0.01 mol% to about 20 mol%, alternatively from about 0.1 mol% to about 15 mol%, alternatively from about 0.2 mol% to about 10 mol%, alternatively from 0.5 mol% to 5 mol%, or alternatively from 1 mol% to 3 mol%.

[0074] Spent catalysts (e.g., decoked, redispersed, calcined, and / or untreated spent catalysts) can be subjected to at least one reactivation step. Reactivation of spent catalysts can be carried out using a reactivation composition containing one or more halogenating agents, including gas-phase halogenating agents, liquid-phase halogenating agents, solid-phase halogenating agents, or combinations thereof. In one embodiment, reactivation of spent catalysts is carried out by contacting the spent catalyst with a fluorine-containing solution, a process commonly referred to as fluorination. The fluorine-containing compound can be in solid phase, liquid phase, gas phase, or a combination thereof. Examples of fluorine-containing compounds suitable for use in the present disclosure include, but are not limited to, tetramethylammonium fluoride (TMAF), ammonium fluoride (NHF or AF), tetrafluoroethylene, 2,2,2-trifluoroethanol (TFE), fluorine (F), hydrofluoric acid (HF), or combinations thereof. In one embodiment, the fluorine-containing compound is a perfluorinated alkane, a perfluorinated alcohol, or a mixture thereof. Examples of perfluorinated alcohols suitable for use in the present disclosure include, but are not limited to, 2,2,2-trifluoroethanol (TFE), hexafluoroisopropanol, tetrafluoropropanol, pentafluoropropanol, hexafluorophenylpropanol, perfluorobutyl alcohol, hexafluoro-2-propanol, pentafluoro-1-propanol, tetrafluoro-1-propanol, 1,1,1,3,3,3-hexafluoro-2-propanol, 2,2,3,3,3-pentafluoro-1-propanol, and mixtures thereof.

[0075] In one embodiment, the fluorine-containing compound is an organic ammonium halide compound and may include one or more compounds represented by the general formula N(R)F, where R represents hydrogen or a substituted or unsubstituted carbon chain molecule having 1 to 20 carbon atoms, and each R may be the same or different. In one embodiment, R' is methyl, ethyl, propyl, butyl, or a combination thereof. Alternatively, R is a methyl group. Examples of suitable organic ammonium compounds include ammonium fluoride (AF), tetramethylammonium fluoride (TMAF), tetraethylammonium fluoride (TEAF), tetrapropylammonium fluoride, tetrabutylammonium fluoride, methyltriethylammonium fluoride, or a combination thereof. Alternatively, the organic ammonium halide compound may include at least one each of hydrofluoric acid and ammonium hydroxide represented by the formula N(R')OH, where R' is hydrogen or a substituted or unsubstituted carbon chain molecule having 1 to 20 carbon atoms, and each R' may be the same or different. In one embodiment, R' can include methyl, ethyl, propyl, butyl, or a combination thereof. Alternatively, R' includes a methyl group. Examples of organic ammonium hydroxides suitable for use in the present disclosure include ammonium hydroxide, tetraalkylammonium hydroxides (e.g., tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide), or a combination thereof.

[0076] In one embodiment, spent catalyst (e.g., decoked, redispersed, calcined, and / or untreated spent catalyst) is contacted with a solution of TMAF at a temperature ranging from about 0° C. to about 200° C., alternatively from about 20° C. to about 100° C., alternatively from about 40° C. to about 60° C., for about 1 to about 100 hours, alternatively from about 0.1 to about 50 hours, alternatively from about 1 to about 24 hours. The solution also contains any suitable solvent.

[0077] In an alternative embodiment, the spent catalyst is reactivated by contacting it with a gas-phase fluorinating agent, such as, for example, fluorine. In such an embodiment, the gas-phase fluorinating agent may be contacted with the spent catalyst for about 1 to about 100 hours, alternatively about 0.1 to about 50 hours, alternatively about 1 to about 24 hours, or alternatively about 4 to about 11 hours.

[0078] In an alternative embodiment, the spent catalyst is reactivated by contact with a solid-phase fluorinating agent, such as, for example, an organic ammonium halide compound, e.g., ammonium fluoride, tetramethylammonium fluoride, or a combination thereof. In such an embodiment, the solid-phase fluorinating agent may be contacted with the spent catalyst at an elevated temperature. The contacting may occur for a period of about 1 minute to about 100 hours, alternatively about 0.1 hours to about 50 hours, alternatively about 1 hour to about 24 hours, or alternatively about 4 hours to about 11 hours. The elevated temperature may range from about 0°C to about 200°C, alternatively about 20°C to about 100°C, or alternatively about 40°C to about 60°C. While not wishing to be limited by theory, it is believed that under these conditions, a portion of the solid-phase fluorinating agent sublimes and migrates into the spent catalyst (e.g., decoked, redispersed, calcined, and / or untreated spent catalyst).

[0079] Choline-containing compounds may also be utilized in the reactivation of spent catalysts. The chlorine-containing compounds may be in the solid phase, liquid phase, gas phase, or a combination thereof. In one embodiment, the chlorine-containing compounds are of the type described previously herein. Examples of chlorine-containing compounds suitable for use in the reactivation composition include, but are not limited to, compounds represented by the general formula N(R)4Cl, where R represents hydrogen or a substituted or unsubstituted carbon chain molecule having 1 to 20 carbons, and each R can be the same or different. In one embodiment, R' is methyl, ethyl, propyl, butyl, or a combination thereof. Alternatively, R is a methyl substituent. Specific examples of suitable organic ammonium chlorine compounds include ammonium chloride, tetramethylammonium chloride (TMAC), tetraethylammonium chloride, tetrapropylammonium chloride, tetrabutylammonium chloride, methyltriethylammonium chloride, or a combination thereof. Alternatively, the choline-containing compound is TMAC.

[0080] In any of the above-described methods for reactivating spent catalysts, the resulting composition may be dried within a temperature range of about 0°C to about 250°C, alternatively about 25°C to about 200°C, alternatively about 50°C to about 150°C, alternatively about 50°C to about 150°C, and / or calcined within a temperature range of about 25°C to about 1000°C, alternatively about 50°C to about 900°C, alternatively about 100°C to about 800°C. Drying and / or calcination may be performed at ambient pressure or under vacuum. During drying and / or calcination, the contacted spent catalyst particles may be stationary or moving, for example, in a rotary dryer. In one embodiment, a weak base may be included during metal reactivation to neutralize any free acid that may be present. Examples of weak bases suitable for use in the present disclosure include, but are not limited to, EDA. After fluorine addition, the resulting composition may be a deashed, redispersed, reactivated spent catalyst.

[0081] In an embodiment, a spent catalyst (e.g., a decoked, redispersed, and / or reactivated spent catalyst) is subjected to multiple reactivation steps. The reactivation steps can be the same; alternatively, the reactivation steps can be different. For example, a spent catalyst (e.g., a decoked and / or redispersed spent catalyst) can be subjected to multiple reactivation steps with a gas-phase fluorinating agent. Alternatively, the spent catalyst can be subjected to a first reactivation step with a liquid-phase fluorinating agent and a second reactivation step with a gas-phase fluorinating agent. In one embodiment, the spent catalyst is subjected to two reactivation steps.

[0082] Spent catalyst (e.g., decoked, redispersed, and / or reactivated spent catalyst) can be heat-treated as described herein to produce a heat-treated spent catalyst. The heat treatment can be carried out in a stationary gas or a flowing gas (i.e., hydrogen, oxygen, air, helium, nitrogen, argon, etc.). For example, the heat treatment can be carried out in a flowing gas containing nitrogen and / or oxygen, air, nitrogen-diluted air, or a combination thereof. In one embodiment, the heat treatment includes calcination, and the calcination step can be carried out by heating the spent catalyst in the presence of oxygen, where the oxygen concentration is about 0.01 mol % to about 20 mol %, alternatively about 0.1 mol % to about 18 mol %, alternatively about 0.2 mol % to about 15 mol %, alternatively about 1 mol % to about 11 mol %, or alternatively about 4 mol % to about 9 mol %. In one embodiment, the spent catalyst is heat treated by calcining within a temperature range of about 25°C to about 1000°C, alternatively about 50°C to about 900°C, alternatively about 100°C to about 800°C, alternatively about 200°C to about 700°C, or alternatively about 300°C to about 600°C. The calcination may be carried out for about 1 hour to about 40 hours, alternatively about 2 hours to about 25 hours, alternatively about 3 hours to about 20 hours, alternatively about 4 hours to about 15 hours, alternatively about 4 hours to about 15 hours, or alternatively about 5 hours to about 10 hours. The calcination step may be carried out by heating the spent catalyst in the presence of oxygen, wherein the oxygen concentration is about 0.01 mol% to about 20 mol%, alternatively about 0.1 mol% to about 15 mol%, alternatively about 0.2 mol% to about 10 mol%, alternatively 0.5 mol% to 5 mol%, or alternatively 1 mol% to 3 mol%. The catalyst upon completion of the regeneration process described herein is referred to as a regenerated or reactivated catalyst.

[0083] In accordance with the present disclosure, the activity of the reactivated catalyst may be designated z, while the activity of the fresh catalyst may be designated x, where x is greater than z. In one embodiment, the reactivated catalyst may have an activity z of from about 0.001x to about 0.95x, alternatively from about 0.7x to about 0.95x, alternatively from about 0.8x to about 0.95x, alternatively about 0.95x.

[0084] After regeneration as described herein, metals may be present in the regenerated catalyst in an amount of about 0.1 wt.% to about 50 wt.%, alternatively about 0.1 wt.% to about 10 wt.%, alternatively about 0.2 wt.% to about 5 wt.%, alternatively about 0.3 wt.% to about 3 wt.%, or alternatively about 0.3 wt.% to about 2 wt.%, based on the total weight of the spent catalyst. As used herein, weight percent of metals is based on the total weight of the catalyst. Chlorides may be present in the regenerated catalyst in an amount of about 0.1 wt.% to about 105 wt.%, alternatively about 0.2 wt.% to about 53 wt.%, or alternatively about 0.3 wt.% to about 32 wt.%, based on the total weight of the catalyst. Fluorides may be present in the regenerated catalyst in an amount of about 0.1 wt.% to about 10 wt.%, alternatively about 0.2 wt.% to about 5 wt.%, alternatively about 0.3 wt.% to about 3 wt.%, or alternatively about 0.6 wt.% to about 2 wt.%, based on the total weight of the catalyst.

[0085] In an embodiment, the regeneration system 140 is operable to move the reforming catalyst through a series of radial flow regeneration reactors. The regeneration reactors may be stacked reactors operable to provide a substantially uniform distribution of the regeneration components (e.g., halogens). The rate at which the catalyst passes through the stack(s) of such regeneration vessels is significantly faster than the rate at which the catalyst passes through the stack(s) of reforming reactors (e.g., it may take a week for the catalyst to pass through a regeneration reactor and more than a year to pass through a reforming reactor as described herein).

[0086] The regenerated reforming catalyst can be introduced into the top radial flow reactor of each of at least one reactor stack or the top radial flow reactor of the first reactor stack via inter-stack transfer. The regenerated reforming catalyst can be introduced into the top radial flow reactor via vessel 150B (e.g., at least one purge chamber) and a replacement catalyst delivery system or transfer line 131. The regenerated catalyst can be reduced before or after delivery to the top of the at least one reactor stack. In an embodiment, vessel(s) 150B includes a reduction vessel integrated with and / or fluidly connected to the top radial flow reactor (e.g., first reactor 110A) into which the regenerated catalyst is introduced, and the regenerated catalyst is reduced in vessel 150B. In an embodiment, the regenerated catalyst is reduced via a reducing gas including hydrogen, nitrogen, a carbonaceous reducing gas such as carbon monoxide (CO), or a mixture thereof. In embodiments, vessel(s) 150B includes a purge vessel integrated with and / or fluidly connected to the top radial flow reactor into which the regenerated catalyst is introduced and in which the regenerated catalyst is contacted with a purge gas. In embodiments, the purge gas comprises nitrogen. In embodiments, a single vessel 150B is utilized as the purge vessel, lock hopper, and / or reduction vessel.

[0087] In an embodiment, the reforming catalyst passes through a regeneration system and returns to the stacked reactor system (e.g., vessel 150B) via a replacement catalyst transfer system over a period of about one week. At start-up, initial fresh catalyst may be introduced, for example, via make-up catalyst line 130 and valve V4, into a downstream vessel or storage unit 140 and further into the stacked reactors of the first stack S1, for example, via vessel 150B(s), where the fresh catalyst may be purged and / or reduced. Alternatively, the fresh catalyst may be purged and / or reduced in the downstream vessel(s) 140 before being transferred to the stacked reactors of the first stack S1.

[0088] In this second variation, during operation, valves V1 and V2 can be open, with valve V3 directing catalyst flow to the first reforming reactor 110A and valve V4 closed. Thus, reforming catalyst can travel from the first reforming reactor 110A through all of the reforming reactors (e.g., from 110A to 110B via line 134, from 110C to 110D via line 135, and exiting 110D) to the regeneration unit 140, as described above. In the regenerator, spent catalyst can be regenerated. Optionally, fresh regenerated catalyst can be introduced into the stacked reactors via regenerated catalyst line 130 and valve V4, and spent catalyst can be purged via catalyst purge line 132 and valve V3. After regeneration (which may take days to weeks in embodiments), the regenerated catalyst may be optionally returned to the first reforming reactor 110A via vessel 150B, where the catalyst may be stored and / or reduced until needed for use in the first reactor 110A.

[0089] As shown in the embodiment of Figure 1, the hydrocarbon feed may flow from the top radial flow reactor to the bottom radial flow reactor in each stack, with the reforming catalyst and hydrocarbon feed flowing co-directionally through at least one reactor stack. In such an embodiment, the operating temperature of a given radial flow reactor may be lower than the operating temperature of a radial flow reactor downstream of the top radial flow reactor. For example, in an embodiment such as that of Figure 1, the first reforming reactor 110A may be operated at a lower temperature than the second reforming reactor 110B, which may be operated at a lower temperature than the third reforming reactor 110C, which may be operated at a lower temperature than the fourth reforming reactor 110D. In an alternative embodiment, the CCR or stacked reactor system is configured such that the hydrocarbon feed passes from the bottom reactor to the top reactor of at least one reactor stack, causing the reforming catalyst and hydrocarbon feed to flow countercurrently through at least one reactor stack. Such countercurrent flow of catalyst and hydrocarbon feed is described in more detail herein with reference to the embodiment disclosed in FIG. 2. Variant 3: Operated in stacked reactors with slow moving catalyst and storage / removal.

[0090] In a third variant of the reforming method according to the present disclosure, the radially stacked reactors are operated to move the reforming catalyst through at least one reactor stack and via a spent or spent catalyst transfer system to a downstream unit for storage and subsequent removal. In such an embodiment, the reforming catalyst may be moved very slowly to an existing downstream regeneration section, where the spent reforming catalyst is removed from the process and replaced with fresh catalyst, which is returned to the stacked reforming reactor section. The downstream unit may be a dedicated storage vessel or a regeneration system for a retrofit CCR system, which may be used for storage in these embodiments. In such an embodiment, the transfer of the spent catalyst to the downstream unit 140 may be as described above with respect to the transfer of the spent catalyst to the regeneration system 140. In these embodiments, the spent catalyst may be stored in the downstream unit 140 until the amount of spent catalyst stored in the regenerator reaches a predetermined threshold amount. At that point, the spent catalyst may be removed therefrom, for example, via the catalyst dump line 132 and valve V3. The removed spent catalyst may be sent to an off-site facility for regeneration, or sent for regeneration or disposal. Off-site regeneration may include the addition of a liquid to the catalyst.

[0091] Fresh catalyst may be introduced into the stacked reactors via catalyst replacement line 131. Fresh catalyst may be introduced, for example, to a downstream vessel or storage unit 140 via make-up catalyst line 130 and valve V4. As previously described, the stacked reactor system may be configured so that the reforming catalyst is first introduced into a purge tank or vessel, optionally connected to or fluidly connected to a reduction reactor connected to or fluidly connected to the top radial flow reactor of at least one of the at least one reactor stack. In embodiments, fresh reforming catalyst is introduced into at least one reactor stack via such purge vessel (e.g., a lock hopper) and / or reduction vessel and is purged and / or reduced as previously described before introduction into at least one reactor stack (e.g., first reactor 110A or reactor stack S1).

[0092] In this third variant, valves V1 and V2 can be opened during operation, and valve V3 can periodically direct catalyst from the regenerator 140 to a catalyst dump via line 132. Valve V4 can be operated to periodically add new catalyst to the downstream unit 140. In an embodiment, fresh catalyst is dried and / or reduced (downstream unit 140 and / or reactor(s) 150B) before being fed to the first reforming reactor 110A. In an embodiment, the aromatization catalyst passes through all reactors of the stack(s) before proceeding to the downstream unit(s) 140 (e.g., from 110A to 110B via line 134, then from 110C to 110D, and exits 110D via line 135). According to the third variant of the reforming method according to the present disclosure, the spent catalyst stored in the downstream unit 140, rather than being regenerated therein, can be sent for disposal. According to a third variant aspect, in an embodiment, an existing CCR can be utilized for aromatization without utilizing the catalyst regeneration function of a conventional CCR process.

[0093] In an embodiment, after the spent catalyst is disposed of, the downstream unit 140 is loaded with new or fresh catalyst. Similar to the second variation described above, this third variation simplifies operation by allowing the plant to maintain substantially steady-state catalyst performance throughout, making continuous catalyst demand predictable, and enabling replacement of the reforming catalyst without shutting down the plant, since replacement catalyst can be introduced from the lock hopper 150B into the first reactor 110A during regeneration (according to an embodiment of Variant 2) or disposal of spent catalyst from the downstream vessel 140 (according to an embodiment of Variant 3). Similar to the second variation, the aromatization catalyst moves very slowly through the stacked reactors, and in an embodiment, it may take 1 to 3 years to move from the first reactor 110A to the regenerator / storage vessel 140 or the lock hopper 150A.

[0094] Operation with catalyst transfer according to Variant 2 and Variant 3 described herein can provide a catalyst aging gradient throughout the reforming reactors (e.g., fresh catalyst is introduced at the inlet of reactor 110A and used sequentially as it passes through reactors 110A, 110B, 110C, and 110D, and is discharged as spent catalyst in the last reactor 110D). In embodiments, the temperatures of the reforming reactors are adjusted according to the different activity levels of the catalyst therein. In embodiments, the operating temperature of each reforming reactor remains substantially constant without increasing significantly during operation. As described above with reference to the second variant and in more detail herein with reference to the embodiment of Figure 2, the hydrocarbon feed and catalyst can flow co-currently, as depicted in the embodiment of Figure 1, or in counter-current flow, and the desired operating temperature in the stacked reforming reactors can be selected accordingly.

[0095] In this third variant of reforming according to the present disclosure, the spent catalyst may be replaced with new catalyst after transfer to a regenerator / storage unit, rather than being regenerated there for reuse. Suitable aromatization catalysts may be less attrition resistant than conventional CCR reforming catalysts, characterized by one or more of a crush strength of at least about 1.5 lbs / mm and / or a catalyst attrition rate of less than about 3.0 wt.%. Furthermore, when the catalyst is removed from the system according to this third variant, extrudates that may generate particulates may also be suitable, given that particulates are removed along with the spent catalyst as they pass through the reactor stacks S1 and S2.

[0096] Either the second or third variants provided herein employ slow movement of the aromatization catalyst through at least one reactor stack, resulting in a faster reaction rate than conventional fixed-bed radial flow reforming reactors, such as AROMAX®. ) Variants 2 and 3 may be operated to provide more efficient catalyst utilization and / or more uniform catalyst demand. Variants 2 and 3 may provide higher catalyst utilization efficiency than Variant 1, in which the reforming reactor of a stacked reactor system is operated as a stationary fixed-bed radial flow reactor. Thus, "spent" catalyst removed from a reactor stack(s) operated according to Variant 2 or Variant 3 may, in embodiments, retain less catalytic activity (e.g., be more fully utilized) than the corresponding catalyst removed from the reactor stack(s), while the reactor is operated as a stationary fixed bed via Variant 1 (due to the nature of reactant flow through the fixed radial bed). In some aspects, "spent" catalyst removed from each reactor operating according to Variant 2 or 3 may have substantially the same activity (i.e., substantially uniform catalyst usage). On the other hand, "spent" catalyst removed from a more upstream reactor in a system operating according to Variant 1 may maintain higher catalytic activity than "spent" catalyst removed from a later reactor. In additional embodiments, the "spent" catalyst removed from each reactor is characterized by variations in catalyst activity levels due, for example, to non-uniform catalyst usage.

[0097] Another stacked reactor system for use in the aromatization method disclosed herein will now be described with reference to Figure 2. Figure 2 is a flow diagram of a stacked reactor system 200 for use in an aromatization process according to another embodiment of the present disclosure. The stacked reactor system 200 includes a first reactor stack S1 and a second reactor stack S2, a heat exchanger 220, a catalyst silo and / or activator 240, a spent catalyst storage vessel 250, and valves V1, V2, V3, V4, V5, and V6. In aspects of the disclosed technology, the heat exchangers may be associated with or form part of a reactor component, for example, or may be incorporated into the system as a heat exchanger absent one or more components associated with the reactor, for example, as known to those skilled in the relevant art.

[0098] The reforming reactor system 200 includes three reforming reactors, the first, third, and fifth reforming reactors 210A, 210C, and 210E, respectively, and the second reactor stack S2 includes three reforming reactors, the second, fourth, and sixth reforming reactors 210B, 210D, and 210F, respectively. In this embodiment, the first reforming reactor 210A is the bottom reforming reactor of the first reactor stack S1 and is located below the third reforming reactor 210C, which is the middle reforming reactor of the first reactor stack S1. The fifth reforming reactor 210E is the top reforming reactor of the first reactor stack S1 and is located above the third reforming reactor 210C. The second reforming reactor 210B is the bottom reforming reactor of the second reactor stack S2 and is located below the fourth reforming reactor 210D, which is the middle reforming reactor of the second reactor stack S2. The sixth reforming reactor 210F is the top reforming reactor of the second reactor stack S2 and is located above the fourth reforming reactor 210D. As previously mentioned, the reforming reactor system of the present disclosure can include a single stack or multiple stacks, including, but not limited to, two, three, or four reactor stacks. In embodiments such as the embodiment of FIG. 2, the reforming system includes two stacks and transport of a hydrocarbon feed between the reactor stacks. In embodiments (e.g., FIG. 1), transport of a reforming catalyst between the reactor stacks is performed. In embodiments such as FIG. 2, there is no transport of a reforming catalyst between the reactor stacks.

[0099] In an embodiment, hydrocarbons supplied for aromatization are introduced into heat exchanger 220 via hydrocarbon feed inlet line 205 and heated to the desired operating temperature. First reactor inlet line 206 carries the heated hydrocarbon feed to first reforming reactor 210A of first reactor stack S1. Within first / lowest reforming reactor 210A, convertible hydrocarbons are contacted with a catalytic reforming catalyst and under operating conditions described herein to convert aromatic hydrocarbons to reformed products comprising BTX. An effluent comprising aromatic hydrocarbons is removed from first reforming reactor 210A via first reactor effluent line 207. The first reactor effluent is introduced into heat exchanger 220 via first reactor effluent line 207, where it is heated to the desired downstream reforming reactor inlet temperature. The heated first reactor effluent is introduced from the heat exchanger 220 via the second reforming reactor inlet line 208 into the second reforming reactor 210B of the second reactor stack S2.

[0100] In the second reforming reactor 210B, the convertible hydrocarbons are converted (via reforming / aromatization) to reformed products comprising BTX via contact with an aromatization catalyst under operating conditions described herein. An effluent comprising aromatic hydrocarbons is removed from the second reforming reactor 210B via a second reforming reactor effluent line 209. The second reactor effluent is introduced via a first reactor effluent line 209 to a heat exchanger 220, where it is heated to the desired downstream reforming reactor inlet temperature. The heated second reactor effluent is introduced from the heat exchanger 220 via a third reforming reactor inlet line 216 to the third reforming reactor 210C of the first reactor stack S1.

[0101] In the third reforming reactor 210C, the convertible hydrocarbons are contacted with a catalytic reforming catalyst and, under operating conditions consistent with the present disclosure, the aromatic hydrocarbons are converted to reformed products comprising BTX. An effluent comprising aromatic hydrocarbons is removed from the third reforming reactor 210C via a third reforming reactor effluent line 217. The third reactor effluent is introduced via the third reforming reactor effluent line 217 into a heat exchanger 220, where it is heated to the desired downstream reforming reactor inlet temperature. The heated third reactor effluent is introduced from the heat exchanger 220 into the fourth reforming reactor 210D via a fourth reforming reactor inlet line 218.

[0102] In the fourth reforming reactor 210D, the convertible hydrocarbons are converted to reformed products containing BTX through contact with a catalytic reforming catalyst under operating conditions according to the present disclosure. An effluent containing aromatic hydrocarbons is removed from the fourth reforming reactor 210D of the second reactor stack S2 via a fourth reforming reactor effluent outlet line 219. The fourth reactor effluent is introduced via the fourth reforming reactor effluent line 219 into a heat exchanger 220, where it is heated to a desired downstream reforming reactor inlet temperature. The heated fourth reactor effluent is introduced from the heat exchanger 220 into the fifth reforming reactor 210E via a fifth reforming reactor inlet line 221.

[0103] In the fifth reforming reactor 210E, the convertible hydrocarbons are converted to reformed products comprising BTX through contact with an aromatization catalyst under operating conditions according to the present disclosure. An effluent comprising aromatic hydrocarbons is removed from the fifth reforming reactor 210E of the first reactor stack S1 via a fifth reforming reactor effluent outlet line 222. The fifth reactor effluent is introduced via the fifth reforming reactor effluent line 222 into a heat exchanger 220, where it is heated to a desired downstream reforming reactor inlet temperature. The heated fifth reactor effluent is introduced from the heat exchanger 220 via a sixth reforming reactor inlet line 223 into the sixth reforming reactor 210F of the second reactor stack S2.

[0104] In the sixth reforming reactor 210F, the convertible hydrocarbons are converted to reformed products comprising BTX under the operating conditions described herein via contact with an aromatization catalyst. An effluent comprising aromatic hydrocarbons is removed from the sixth reforming reactor 210F of the second reactor stack S2 via the sixth or last reforming reactor effluent, or "hydrocarbon product," outlet line 225.

[0105] A stacked reactor system such as that of Figure 2 may be operated according to the first, second, or third variant described above with reference to the embodiment of Figure 1. In an embodiment, a stacked reactor system such as that of Figure 2 is operated via the first variant described above with the reforming reactor operated as a stationary fixed bed.

[0106] In other embodiments, a system such as that of FIG. 2 operates with a continuous transfer of catalyst, as in the second and third variations described herein. For example, in embodiments, catalyst silo and / or activator 240 is periodically filled with fresh catalyst, regenerated catalyst, or spent catalyst (which is then regenerated). For example, fresh catalyst is introduced into catalyst silo and / or activator 240 via fresh catalyst or make-up catalyst inlet line 230 and valve V4. The catalyst may then be dried and / or reduced as described herein with reference to the embodiment of FIG. 1. The catalyst may be dried and / or reduced in catalyst silo 240 or via vessel(s) corresponding to vessel(s) 150B described above with reference to the embodiment of FIG. 1. For example, vessel 150B may be attached to and / or fluidly connected to the top reactor of each reactor stack (e.g., in the embodiment of FIG. 2, attached to and / or fluidly connected to the fifth reactor 210E of reactor stack S1 and the sixth reactor 210F of second reactor stack S2). A process gas, such as hydrogen or nitrogen, may be introduced into catalyst silo and / or activator 240 via process component inlet line 241, and exhaust gases generated during processing may be removed from catalyst silo and / or activator via exhaust gas outlet line 242.

[0107] The prepared catalyst can be slowly fed to the top of one or more stacked reactor beds. In the embodiment of Figure 2, the catalyst is slowly fed to the fifth reforming reactor 210E, the top reactor of the first reactor stack S1, via replacement catalyst transport line 231A and valve V5, and the catalyst is slowly fed to the sixth reforming reactor 210F, the top reactor of the second reactor stack S2, via replacement catalyst transport line 231B and valve V6, or the catalyst can be fed to both the fifth reactor 210E of stack S1 and the sixth reactor 210F of stack S2. Catalyst slowly flows through reactor stack S1 from the fifth reforming reactor 210E to the bottom reforming reactor of reactor stack S1 (i.e., the first reforming reactor 210A), and then through reactor stack S2 from the sixth reforming reactor 210F to the bottom reforming reactor of second reactor stack S2 (i.e., the second reforming reactor 210B), thereby providing a catalyst activity gradient, as described further herein. Spent catalyst can be removed from the bottom reactor of each reactor stack. For example, in the embodiment of FIG. 2, spent or spent catalyst can be removed from the first reforming reactor 210A via valve V1 and spent or spent catalyst transport line 235A, from the second reforming reactor 210B via valve V2 and spent or spent catalyst transport line 235B, or from both.

[0108] In an embodiment, spent catalyst is introduced into spent catalyst silo 250 via spent catalyst transport lines 235A and 235B. The spent catalyst can be regenerated by the second variant described above and, optionally, via purging and / or reduction, returned to the reactor stack as described above. In an embodiment, the spent catalyst is returned to catalyst silo and / or activator 240 for reactivation / regeneration. Regeneration can be carried out as described herein with respect to the embodiment of FIG. 1. For example, a regeneration component suitable for decoking, oxychlorination, halogenation, or a combination thereof can be introduced into catalyst silo and / or activator 240 via process component inlet line 241, and exhaust gas produced during regeneration / reactivation can be removed from the catalyst silo and / or activator via exhaust gas outlet line 242.

[0109] In an embodiment, the system 200 is operated according to Variant 3 described herein with reference to the embodiment of FIG. 1, and the spent catalyst in the spent catalyst silo 250 is directed to regeneration and / or disposal via the catalyst purge line 232 and valve V3.

[0110] The time frame for catalyst to move from the top to the bottom of a stacked reactor (e.g., reactors in stacks S1 and / or S2) can take months or even years, depending on the size of the equipment and the method of operation. While the embodiment of FIG. 2 depicts each reactor stack as increasing in size from top to bottom, as discussed with reference to the embodiment of FIG. 1, the reactors within a reactor stack can increase, decrease, or remain the same in size from top to bottom. For example, in an embodiment, the largest reactor in each stack can be the top reactor. The volume percentage of catalyst within the reactors can be as described above with reference to the embodiment of FIG. 1. For example, in an embodiment, the volume ratio / percentage of total aromatization catalyst in the first, second, third, fourth, fifth, and sixth reactors can be about 10%:10%:10%:20%:20%:30%.

[0111] As shown in the embodiment of FIG. 2, a stacked reactor or CCR system can be configured to introduce a fresh hydrocarbon feed into the bottom reactor of one of at least one reactor stacks and pass it upward through each reactor stack, with the reforming catalyst and hydrocarbon feed flowing countercurrently through at least one reactor stack. In this manner, relatively less active or less active catalysts (e.g., catalysts at the bottom of the reactor stack) can catalyze the easiest reactions, potentially allowing lower temperatures to be used in these reactors (e.g., the first and second reforming reactors 210A and 210B). Utilizing lower temperatures can reduce cracking and improve selectivity. The feed is more converted as it passes upward through the reactor stack(s) and comes into contact with fresher / more active catalyst. Higher reaction temperatures can be utilized in the reforming reactors at the top of the stack(s) (e.g., the fifth and sixth reforming reactors 210E and 210F), which contain the freshest catalysts. This fresher catalyst can promote more difficult reactions with greater selectivity. In such embodiments, the operating temperature of each reactor (e.g., the lower or bottom reactor) of the at least one reactor stack can therefore be lower than the operating temperature of the higher reactor (e.g., the upper or top reactor).

[0112] Countercurrent operation can reduce the risk of process upsets. In embodiments, the bottom reactor of at least one reactor stack into which the hydrocarbon feed is introduced, or at least the first reactor, functions as a guard bed to protect downstream reactors containing more active catalysts from at least one undesirable compound. For example, in the embodiment of FIG. 2, the bottom reactor of the first reactor stack S1 (i.e., the first reforming reactor 210A) or both the first reactor 210A and the bottom reactor of the second reactor stack S2 (i.e., the second reforming reactor 210B) can operate as catalyst guard beds. The guard bed reactor(s) can help remove undesirable compounds or poisons, such as, but not limited to, sulfur, heavy components, nitrogen, iron, or combinations thereof. Furthermore, in the event of an unforeseen event, the spent catalyst in the guard bed(s) can be removed closest to the reactor stack(s), for example, due to its proximity to catalyst discharge lines 235A and 235B at the bottom of reactor stacks S1 and S2, thereby facilitating removal of inactive catalyst without the need to shut down the plant or operate it at reduced performance for extended periods. Utilizing such a method may enable a reforming reactor system that does not include a sulfur conversion adsorption unit (SCA) upstream of the CCR or stacked reactor system, since the most depleted catalyst in each reactor stack is in contact with the freshest hydrocarbon feed.

[0113] While the hydrocarbon feed is depicted passing from the bottom reactor to the top reactor in each reactor stack, in embodiments, stacked reactor system 200 can be configured so that the hydrocarbon feed passes downward from the top radial flow reactor in each stack to the bottom radial flow reactor, such that the reforming catalyst and hydrocarbon feed flow co-directionally through the stack. In such embodiments, the operating temperature of a given radial flow reactor can be lower than and / or below the operating temperature of the downstream radial flow reactor. Furthermore, the relative sizes of the reactors and the volumetric distribution of catalyst within reactor stacks S1 and S2 can be reversed from that shown in FIG. 2. aromatization catalyst

[0114] In one embodiment, the aromatization catalyst support comprises a support. In an embodiment, the support comprises an inorganic oxide. The inorganic oxide may include a binding medium and / or large pore zeolites (aluminosilicates), amorphous inorganic oxides, and mixtures thereof. Large pore zeolites include, but are not limited to, L-zeolites, Y-zeolites, mordenite, omega zeolites, beta zeolites, or other types of zeolites. Amorphous inorganic oxides include, but are not limited to, aluminum oxide, silicon oxide, and titanium oxide. The support may further comprise a binder, such as, for example, silica, alumina, clay, titania, and magnesium oxide. In certain aspects, the support is not primarily or essentially alumina-based. In an embodiment, the zeolite support comprises a silica-bound L-zeolite support. In further aspects, the catalyst may be characterized by comprising one or more of the following: The catalysts used in accordance with the disclosed systems and methods may be characterized by: pellet-like morphology (e.g., compared to spherical morphology), relatively low crush strength, zeolite support (e.g., compared to alumina support), fluoride or fluorine, and inclusion of platinum (Pt) as the catalytic metal (e.g., compared to the presence of platinum (Pt) and tin (Sn) or platinum (Pt) and rhodium (Rh), and relatively low acidity (e.g., compared to typical reforming catalysts). In advantageous embodiments, the catalysts used in accordance with the disclosed systems and methods may further be characterized by significantly higher benzene selectivity, relatively less cracking, and less coke production (e.g., compared to typical reforming catalysts).

[0115] In one embodiment, the catalyst support comprises a medium- or large-pore zeolite. The term "zeolite" generally refers to certain hydrous crystalline metal aluminosilicates. These zeolites exhibit a network of SiO4 and ALO4 tetrahedra in which aluminum and silicon atoms are linked in a three-dimensional framework by shared oxygen atoms. In this structure, the ratio of oxygen atoms to the sum of aluminum and silicon atoms can be equal to 2. This structure exhibits a negative charge, which is usually balanced by the inclusion of metal, alkali metal, alkaline earth metal, and hydrogen cations within the crystal.

[0116] In one embodiment, the catalyst support comprises type L zeolite. Type L zeolite supports are a subgroup of zeolite supports. A typical type L zeolite comprises oxides in a molar ratio according to the following formula: M2 / nOAl2O3xSiO2yH2O where "M" represents at least one exchangeable cation, such as barium, calcium, cerium, lithium, magnesium, potassium, sodium, strontium, and zinc, as well as non-metallic cations such as hydronium and ammonium ions that may be replaced by other exchangeable cations without significantly altering the basic crystal structure of zeolite L. Where "n" represents the valence of "M," "x" is 2 or greater, and "y" is the number of water molecules contained in the channels or pores of the zeolite.

[0117] In one embodiment, the catalyst support comprises a bound potassium L-type zeolite, also known as KL zeolite. As used herein, the term "KL zeolite" refers to an L-type zeolite in which the predominant cation M incorporated in the zeolite is potassium. KL zeolite may be cation-exchanged with or impregnated with another metal and one or more halides to produce a platinum-impregnated halide zeolite catalyst or a KL-supported Pt-halide zeolite catalyst. In some embodiments, the support is a KL zeolite. In other embodiments, the catalyst support may comprise a mixture of zeolite and an inorganic oxide.

[0118] The catalyst support may contain up to about 95 wt. % L-zeolite, alternatively from about 60 wt. % to about 95 wt. %, alternatively from about 70 wt. % to about 92 wt. %, and alternatively from about 80 wt. % to about 90 wt. % L-zeolite, based on the total weight of the support. In accordance with the present disclosure, weight percent based on the total weight of the catalyst support refers to the weight percent of a component based on the final weight of the catalyst support.

[0119] In one embodiment, the catalyst comprises one or more catalytically active metals. Examples of such metals include, but are not limited to, Group IB metals and Group VIII transition metals of the periodic table, such as iron (Fe), cobalt (Co), nickel (Ni), ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), silver (Ag), copper (Cu), or combinations thereof. In one embodiment, the metal comprises platinum (Pt).

[0120] In one embodiment, the metal may be present in the catalyst in an amount of from about 0.1 wt.% to about 50 wt.%, alternatively from about 0.1 wt.% to about 10 wt.%, alternatively from about 0.2 wt.% to about 5 wt.%, alternatively from about 0.3 wt.% to about 3 wt.%, alternatively from about 0.3 wt.% to about 2 wt.%, based on the total weight of the catalyst. As used herein, weight percent of the metal is based on the total weight of the catalyst.

[0121] In one embodiment, the catalyst comprises at least two halides. Examples of suitable halides include chloride, fluoride, bromide, iodide, or a combination thereof. In one embodiment, the catalyst comprises chloride. The chloride may be present in the catalyst in an amount of from about 0.1 wt. % to about 5 wt. %, alternatively from about 0.2 wt. % to about 3 wt. %, alternatively from about 0.3 wt. % to about 2 wt. %, based on the total weight of the catalyst.

[0122] In one embodiment, the catalyst comprises a fluoride, which may be present in the catalyst in an amount from about 0.1 wt % to about 10 wt %, alternatively from about 0.2 wt % to about 5 wt %, and alternatively from about 0.3 wt % to about 3 wt %, based on the total weight of the catalyst.

[0123] In various embodiments, the catalyst comprises platinum (Pt) and chloride (Cl) in an atomic ratio of Pt:Cl of from about 1.0:0.1 to about 1.0:20, alternatively from about 1.0:0.2 to about 1.0:15.0, alternatively from about 1.0:0.3 to about 1.0:10.0 (including from about 1.0:0.5 to about 1.0:10, from about 1.0:1.0 to about 1.0:5.0, from about 1.0:2.0 to about 1.0:5.0, and about 1.0:4.5).

[0124] In one embodiment, a fresh catalyst may function to catalyze a user-desired process, such as the aromatization of one or more hydrocarbons. As catalysts are used to convert hydrocarbons into desired products (e.g., aromatization), catalytic activity may decrease over time due to various factors. For example, carbonaceous material may accumulate on the catalyst, thereby reducing the number of available catalytic sites and reducing the overall activity of the catalyst. In other examples, catalyst modifiers, or activity promoters, may evolve from the catalyst over time, resulting in reduced activity or selectivity to desired products. Catalyst activity or selectivity may decrease to a level where it is no longer beneficial to use the catalyst in the user-desired process and / or where regeneration is desired to enhance / restore catalytic activity. Such catalysts may be characterized as "spent" catalysts.

[0125] In embodiments, the reforming catalyst is about 15, 14, 13, 12, 11, or 10 lb f In an embodiment, the reforming catalyst has a crush strength of from about 7.5 to about 15 lbs. f In embodiments, the catalyst is an extrudate. In embodiments, the catalyst is cylindrical. In embodiments, the catalyst is spherical. In embodiments, the catalyst comprises an AROMAX® catalyst in the form of a sphere. In embodiments, the catalyst comprises an AROMAX® catalyst in the form of a cylindrical and / or spherical extrudate. The catalyst may have a size ranging from about 0.1 inch to about 0.21 inch in length (for cylindrical extrudates) and a circumference ranging from about 0.01 inch to about 0.50 inch, such as from about 0.05 inch to about 0.25 inch (for spherical extrudates). Aromatization operating conditions

[0126] The aromatization in the reforming reactor may be carried out under suitable operating conditions known to those skilled in the art. In embodiments, the reactor is operated at a temperature ranging from about 400°C to about 600°C, including from about 450°C to about 550°C, at a pressure ranging from about 30 psig to about 100 psig, including from about 50 psig to about 70 psig, for about 1.0 h. -1 ~about 4h- 1 (about 1.0h -1 ~about 2.3h- 1 and a liquid hourly space velocity (LHSV) in the range of from about 1.0 to about 5.0 mole:mole, for example, from about 2.0 to about 4.0 mole:mole, or a combination thereof. Retrofitting a CCR system with AROMAX® catalyst

[0127] As previously described, in embodiments, an existing CCR system is converted and / or retrofitted for use with an aromatization catalyst, such as an AROMAX® catalyst. In embodiments, a method of operating a continuous catalyst regeneration (CCR) system according to the present disclosure includes running the CCR system to convert hydrocarbons in a hydrocarbon feed to aromatic hydrocarbons, the catalyst being continuously circulated in a flow loop within the CCR system, and the entire catalyst being regenerated at least once a week; shutting down the CCR system to cease converting convertible hydrocarbons to aromatic hydrocarbons; and replacing the existing catalyst in the CCR system with a replacement catalyst comprising platinum, fluorine, and chlorine on a silica-bound L-zeolite support. In embodiments, the method further includes starting up the CCR to continue converting hydrocarbons in the hydrocarbon feed to aromatic hydrocarbons, the replacement catalyst not being continuously circulated in a flow loop within the CCR system. In embodiments, the replacement catalyst is static within the CCR system during the conversion of hydrocarbons in the hydrocarbon feed to aromatic hydrocarbons, and the method proceeds according to the first variant described above, with the moving-bed reactor system (i.e., the CCR system) being operated in a stationary or static mode. In alternative embodiments, the method further includes starting the CCR to continue the conversion of the convertible hydrocarbons to aromatic hydrocarbons, and the replacement catalyst is circulated intermittently or continuously in a flow loop within the CCR system, and the method includes the second or third variant described above. In some such embodiments, the entire catalyst is regenerated no more than once per year. In some such embodiments, the entire catalyst is passed through the reforming reactor stack in the CCR no more than once per year. Features and Potential Benefits

[0128] This disclosure describes one method of using a CCR reactor set up in either a retrofit or conventional design in the application of AROMAX® technology available from Chevron Phillips Chemical (The Woodlands, Texas). As disclosed herein, the process of operating a stacked reactor system using AROMAX® catalyst differs from conventional CCR operation in several ways. According to embodiments of the present disclosure, an existing CCR can be converted to use a reforming radial flow reactor operated as a stationary fixed bed, thereby utilizing a moving bed reactor system in a fixed bed process. Such operation may provide for more rapid catalyst changeover during exchange than conventional fixed bed radial flow reactor systems.

[0129] According to embodiments of the present disclosure, an existing CCR is retrofitted for use with an aromatization catalyst by slowly transferring the catalyst from the stacked reactor to a regenerator and / or storage section (e.g., according to the second and third variants described herein) as described herein. Desirably, minimal equipment changes are required when converting from a CCR reformer to an AROMAX® system as described herein. In embodiments, the regeneration is retrofitted to allow for the use of fluorine for catalyst regeneration. The interior of reforming reactors is often coated with tin MPT to prevent carbonization of the metal due to the low sulfur environment in the AROMAX® process. However, the presence of tin MPT can be problematic with conventional regeneration procedures. An advantage of using a CCR setup as described herein for aromatization catalyst regeneration can be the ability to use a regenerator that is not coated with tin MPT. This can facilitate effective catalyst regeneration and lead to significant catalyst cost savings.

[0130] The method disclosed herein and conventional CCR processes have significantly different regeneration frequency time frames. According to embodiments of the present disclosure, with fresh catalyst in the first reforming reactor and spent catalyst in the last reactor in the series, the CCR can operate with aromatization catalyst at varying temperatures. Retrofitting an existing CCR for use as an AROMAX® plant can offer significant capital cost savings compared to conventional production.

[0131] In conventional CCR processes, catalysts are typically regenerated approximately once a week. According to the present disclosure, a CCR system can operate with the aromatization catalyst (e.g., AROMAX® catalyst) regenerated annually or less frequently. Slow movement of the aromatization catalyst through the stacked reactor system (according to the second and third variants provided herein) can help prevent or minimize catalyst dusting. This approach may enable the use of CCR reactor systems with catalysts whose attrition characteristics are generally considered too sensitive for such applications. For example, in an embodiment, the aromatization catalyst is a silica-bound L zeolite. The reduced catalyst regeneration frequency provided by the methods disclosed herein may enable the use of such silica-bound catalysts in processes (e.g., CCR processes) that typically operate with stronger or more robust reforming catalysts. In an embodiment, the catalyst requires only two to three regenerations over a five-year period.

[0132] As described herein, in conventional fixed-bed radial flow aromatization reactor designs, catalyst near the center pipe is often underutilized, and catalyst located inside the fixed-bed radial flow reactor typically retains some activity when discarded at the end of a run. Variants 2 and 3 of the reforming process disclosed herein provide for catalyst remixing and replacement as the catalyst slowly moves from the first reforming reactor to a regenerator or storage unit. This may provide more complete catalyst utilization (i.e., a more complete and uniformly depleted catalyst) than that provided by conventional fixed-bed reactor processes. Variants 2 and 3, which use slow catalyst movement through at least one reactor stack, also allow for aromatization catalyst changes without plant shutdown. This can be expected to significantly reduce turnover times. Variants 2 and 3 also provide operation of the AROMAX® catalyst system with substantially steady-state performance and more predictable catalyst demand, thus facilitating operation.

[0133] As described herein, operation with a reforming catalyst and a hydrocarbon feed flowing in countercurrent mode allows, in embodiments, the hydrocarbon feed to first contact the most depleted catalyst (e.g., having a relatively low activity compared to the fresh catalyst) or a catalyst at or near the lower activity value of a catalyst activity gradient progressing from higher to lower activity values. This spent catalyst can serve to catalyze the simplest reactions, and lower temperatures can be used in these reforming reactors, resulting in reduced cracking and higher selectivity. As the hydrocarbon feed becomes more converted, it contacts the fresher catalyst. Higher reaction temperatures are available in downstream reactors, which in such embodiments may contain the freshest catalyst. This fresh catalyst can more selectively promote more difficult reactions with high selectivity. Such countercurrent operation can also help reduce the risk of process upsets, as sulfur and heavy components in the feed first contact the most depleted catalyst closest to the one being removed from the system. Thus, the spent catalyst can act to protect the fresh catalyst. Furthermore, after an upset, deactivated catalyst can be easily removed without shutting down the plant or operating at reduced catalyst performance for an extended period of time. Due to this countercurrent catalyst migration and placement of the most depleted catalyst in the hydrocarbon feed, such operation may, in embodiments, eliminate the need for an SCA system (e.g., eliminating the need for one or more sulfur guard beds). Other benefits noted above may also be realized through this countercurrent flow.

[0134] The specific embodiments disclosed above are illustrative only, as the disclosure may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations to the details of construction or design herein shown are intended, other than as described in the appended claims. Accordingly, it will be apparent that the specific exemplary embodiments disclosed above may be altered or modified, and all such variations are considered within the scope and spirit of the disclosure. Alternative embodiments resulting from the combination, integration, and / or omission of features of the embodiment(s) are also within the scope of the disclosure. While compositions and methods are described in broad terms as "having," "comprising," "containing," or "including" various components or steps, the compositions and methods may also "consist essentially of" or "consist of" various components or steps. The use of the term "optionally" with respect to a claim element means that the element is required, or alternatively, the element is not required, with both alternatives being encompassed within the scope of the claim. Additionally, terms in the claims shall have their plain and ordinary meaning unless expressly and unambiguously defined by the patentee. Moreover, the indefinite articles "a" or "an," as used in the claims, are defined herein to mean one or more than one of the element they introduce. In the event of any inconsistency in the usage of a word or term in this specification and one or more patents or other documents, the definition consistent with this specification shall prevail.

[0135] All numbers and ranges disclosed above may vary by some amount. When a numerical range with a lower and upper limit is disclosed, all numbers and ranges within that range are specifically disclosed. Specifically, all ranges of values ​​disclosed herein (in the form "about a to about b," or equivalently, "about a to b," or equivalently, "about a to b") are understood to represent all numbers and ranges encompassed within the broader range of values. When a numerical range or limit is explicitly stated, it should be understood that such explicit range or limit includes all iterative ranges or limits of the same order that fall within the explicitly stated range or limit (e.g., about 1 to about 10 includes 2, 3, 4, etc.; greater than 0.10 includes 0.11, 0.12, 0.13, etc.). For example, a lower limit R l and upper limit R u When a numerical range is disclosed, all numbers within that range are specifically disclosed. In particular, the following numbers within the range are specifically disclosed: R = R l +k*(Ru-R l ) where k is a variable ranging from 1 percent to 100 percent in 1 percent increments, i.e., k is 1 percent, 2 percent, 3 percent, 4 percent, 5 percent, 50 percent, 51 percent, 52 percent, 95 percent, 96 percent, 97 percent, 98 percent, 99 percent, or 100 percent. Additionally, numerical ranges defined by two R numerical values ​​defined above are also specifically disclosed.

[0136] While specific embodiments of the present disclosure have been shown and described, modifications thereof can be made by those skilled in the art without departing from the teachings of the present disclosure. The embodiments described herein are illustrative and not limiting. Many variations and modifications of the invention disclosed herein are possible and are within the scope of the invention.

[0137] Additional modifications, equivalents, and alternatives will be apparent to those skilled in the art upon fully understanding the above disclosure. It is intended that the following "claims" be interpreted to encompass all modifications, equivalents, and alternatives. Accordingly, the scope of protection is not limited by the above description, but is limited only by the following appended claims, which scope includes all equivalents of the subject matter of the claims. Each and every claim is incorporated into the specification as an embodiment of the present disclosure. Accordingly, the claims are further explanation and in addition to the detailed description of the present disclosure. The disclosures of all patents, patent applications, and publications cited herein are hereby incorporated by reference.

Claims

1. 1. A reforming reactor system comprising: a continuous catalyst regeneration (CCR) system comprising at least one reactor stack, each reactor stack comprising at least two radial flow reactors each containing a reforming catalyst capable of catalyzing the conversion of hydrocarbons in a hydrocarbon feed to produce a reactor effluent comprising aromatic hydrocarbons; a regeneration reactor system connected to the at least one reactor stack via a spent catalyst transfer system and configured to regenerate the reforming catalyst; the reforming reactor system is configured to move the reforming catalyst through the at least one reactor stack for a period of at least 180 days; The reforming reactor system, wherein the reforming catalyst comprises a Group VIII metal, a silica-bound L-type zeolite support, and at least one halogen.

2. The reforming catalyst is about 15, 13, or 10 lb ｆ 10. The reforming reactor system of claim 1, comprising an extrudate characterized by a crush strength of less than 1000 MPa.

3. 10. The reforming reactor system of claim 1, wherein the at least one halogen comprises fluorine, and the regeneration reactor system is operable to refluorinate the reforming catalyst once it has been exhausted.

4. 10. The reforming reactor system of claim 1, wherein at least one surface or component of the regenerative reactor system is not coated with tin MPT.

5. 10. The reforming reactor system of claim 1, wherein the CCR system comprises: initially introducing a reforming catalyst into at least one top reactor via a purge vessel and a reduction reactor, wherein the at least one top reactor is the top reactor of one of the at least one reactor stack; introducing a fresh hydrocarbon feed into the top reactor, with the reforming catalyst and the hydrocarbon feed flowing co-directionally through the at least one reactor stack; or a fresh hydrocarbon feed is introduced into a lowermost radial flow reactor of one of the at least one reactor stacks such that the reforming catalyst and the hydrocarbon feed flow in countercurrent, wherein each lowermost radial flow reactor of the at least one reactor stack functions as a guard bed to protect a reactor downstream of the at least one reactor stack containing a more active catalyst from at least one undesirable compound selected from sulfur, heavy components, nitrogen, or a combination thereof.

6. 10. The reforming reactor system of claim 1, wherein the reforming reactor system does not include a sulfur conversion sorbent (SCA) upstream of the CCR system.

7. 1. A method of operating a reforming reactor system, comprising: The method includes operating the reactors of a stacked reactor system comprising at least one reactor stack, each of the at least one reactor stack comprising at least two stacked radial flow reactors, each radial flow reactor comprising a reforming catalyst capable of catalyzing the conversion of hydrocarbons of a hydrocarbon feed selected from convertible hydrocarbons having 6 or 7 carbon atoms and no internal quaternary carbons, and convertible hydrocarbons having 6 carbon atoms and no two adjacent internal tertiary carbons, to provide a reactor effluent comprising aromatic hydrocarbons, the reforming catalyst comprising a Group VIII metal, a silica-bound L-type zeolite support, and at least one halogen; the stacked reactor system being operable to move the reforming catalyst through the at least one reactor stack and via a catalyst transfer system to a regeneration system over a period of at least 180 days.

8. 8. The method of claim 7, wherein operating the reactors of the stacked reactor system includes operating the radial flow reactors as stationary fixed beds, and not moving the reforming catalyst during operation.

9. 8. The method of claim 7, converting the convertible hydrocarbons in the hydrocarbon feed until the reforming catalyst is determined to be a spent reforming catalyst; and after the catalyst is determined to be spent, ceasing the introduction of the hydrocarbon feed; and purging the reactor until the reactor effluent contains less than about 200 ppm hydrocarbons; allowing the reactor to reach ambient temperature; removing the spent reforming catalyst in the radial flow reactor of each reactor stack by inter-stack transfer through the bottom radial flow reactor of each reactor stack or through the bottom reactor of a final reactor stack, wherein the catalyst flows downward through the at least one radial flow reactor stack for removal; adding fresh reforming catalyst to the top of the top radial flow reactor of each reactor stack or to the top of the top radial flow reactor of the first reactor stack by inter-stack transfer, wherein the fresh reforming catalyst flows downward through the at least one radial flow reactor.

10. 8. The method of claim 7, wherein the reforming reactor system further comprises at least one purge chamber fluidly attached to the bottom radial flow reactor of each reactor stack or the bottom reactor of a final reactor stack, and wherein transfer occurs between stacks, and the spent reforming catalyst is removed from the bottom radial flow reactor through the purge chamber prior to removing the catalyst from the stacked reactor system.

11. 8. The method of claim 7, wherein the stacked reactor system further comprises at least one purge chamber fluidly connected to the top radial flow reactor of each reactor stack or to the top reactor of the first reactor stack operable for inter-stack transfer, and the fresh reforming catalyst is added to the top radial flow reactor through the purge chamber.

12. 8. The method of claim 7, wherein the catalyst transfer system fluidly connects at least one purge chamber to the top of the regeneration system, and the reforming catalyst is transported to the regeneration system by inter-stack transfer through at least one purge chamber attached to the bottommost radial flow reactor of each of the one reactor stack or the bottommost radial flow reactor of the last of the at least one reactor stack.

13. 8. The method of claim 7, further comprising: regenerating the reforming catalyst by a regeneration process comprising decoking, chlorination, oxychlorination, fluorination, reduction, or a combination thereof as it passes through the regeneration system; and introducing the regenerated reforming catalyst into a top radial flow reactor of each of the at least one reactor stacks or a top radial flow reactor of a first reactor stack with inter-stack transfer.

14. 8. The method of claim 7, wherein the regeneration system is operable to provide transfer of the reforming catalyst through a series of radial flow regeneration reactors, the reforming catalyst passing through the regeneration system and returning to the stacked reactor system via a regenerated catalyst transfer system over a period of about 170 hours.

15. 8. The method according to claim 7, wherein the stacked reactor system further includes a regenerator, the regenerator is used to store spent catalyst, and when the amount of spent catalyst stored in the regenerator reaches a predetermined threshold amount, the spent catalyst stored in the regenerator can be regenerated.

16. 8. The method of claim 7, further comprising: loading the fresh reforming catalyst into a purge chamber and a reduction vessel prior to loading into a top reactor of the at least one reactor stack; and reducing the fresh reforming catalyst prior to introducing it as the replacement catalyst into the top reactor of the at least one reactor stack.

17. 8. The method of claim 7, wherein the stacked reactor system is configured for initial introduction of reforming catalyst into a purge tank connected to a reduction vessel connected to a top radial flow reactor of one of the at least one reactor stack.

18. 8. The method of claim 7, wherein the stacked reactor system comprises: introducing a fresh hydrocarbon feed into the top radial flow reactor, with the reduced reforming catalyst and the hydrocarbon feed flowing co-directionally through the at least one reactor stack; or introducing a fresh hydrocarbon feed into a bottom reactor of one of the at least one reactor stacks, and causing the reforming catalyst and hydrocarbon feed to flow countercurrently through the at least one reactor stack.

19. 20. The method of claim 18, wherein the operating temperature of the top radial flow reactor is lower than the operating temperature of a radial flow reactor downstream of the top radial flow reactor.

20. 10. The method of claim 7, wherein the operating temperature of a bottom reactor of each of the at least one reactor stack is lower than the operating temperature of its upper reactor, and the bottom reactor of each of the at least one reactor stack can function as a guard bed to protect a reactor downstream of the at least one reactor stack containing a more active catalyst from at least one undesirable compound containing sulfur, heavy components, nitrogen, or a combination thereof.

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