Conversion of heavy aromatic compounds to lighter aromatic compounds with low ring saturation and hydrocarbon cracking

Abstract

A catalyst for converting C9+ aromatics to lighter aromatics comprises metal functional groups derived from a metal such as platinum confined in cages and / or channels of a microporous material such as chabazite, wherein the cages and / or channels of the microporous material comprise metal functional groups defined by 8 or fewer tetrahedral atoms and acidic functional groups derived from an additional zeolite having cages and / or channels defined by 10 or more tetrahedral atoms, wherein the microporous material providing the metal functional groups and the additional zeolite providing the acidic functional groups are bound together by a binder.

Description

[Technical Field]

[0001] This application relates to catalyst systems for converting C9+ aromatic compounds to lighter aromatic compounds, and in particular, embodiments relate to catalyst systems configured for hydrogenating light olefins produced by the in situ removal of C2+ alkyl groups from C9+ aromatic compounds. [Background technology]

[0002] In the refining and petrochemical industries, benzene, toluene, and xylenes are often intentionally produced as feedstocks for downstream chemical processes. Benzene, toluene, and xylenes, sometimes referred to by the acronym BTX, are important feedstocks for the production of, for example, styrene, phenolic resins, polycarbonates, nylons, polyurethanes, polyesters, and automotive fuels. BTX can be produced by several chemical processes, such as catalytic reforming of naphtha and stream cracking of naphtha. However, the quality of xylenes obtainable from reforming and stream cracking is limited. Therefore, a solution to producing xylenes has been found: the transalkylation of C9+ aromatic hydrocarbons with benzene and / or toluene over a zeolite catalyst containing precious metals. However, during the transalkylation of C9+ aromatic compounds with, for example, toluene, to produce xylenes and benzene, it can be difficult to separate the desired product at a high purity level because saturated by-products boiling in the same temperature range as the desired aromatic product may be produced. These saturated by-products can be obtained, for example, by hydrogenation of C aromatic compounds produced by transalkylation, dealkylation, and hydrogenation chemical reactions. Commercial benzene product specifications can require a purity of 99.85 wt% or higher. However, the initial benzene purity after distillation of the transalkylation reaction product can be in the range of about 99.2 wt% to 99.5 wt% due to the presence of azeotropic species such as methylcyclopentane, cyclohexane, methylcyclohexane, 2,3-dimethylpentane, dimethylcyclopentane, and 3-methylhexane. Therefore, an additional extraction step is usually required to further improve the purity of the benzene product to the desired level.

[0003] Additionally, several problems have arisen as refineries and chemical plants focus on the production of benzene and xylenes by transalkylating lower C9+ aromatics with benzene or toluene to produce xylenes. Ideally, chemical plants would like to process as many heavy C9+ aromatics as possible while minimizing and possibly eliminating the toluene / benzene co-feed. Both transalkylation and dealkylation activity are important for a successful catalyst system. In transalkylation, methyl groups can be transalkylated to form xylenes. In dealkylation, ethyl, propyl, and butyl groups present on C9+ aromatics can be dealkylated to form lower methyl / ring species, which can then be transalkylated with higher methyl / ring species to form xylenes. Metal functionality on the catalyst is required to saturate the olefins formed during dealkylation while minimizing aromatic saturation. As plants seek to increase the amount of C9+ aromatics in the feed, acceptable activity and catalyst life become an issue.

[0004] Transalkylation catalyst life is highly dependent on the presence of aromatic feedstocks containing alkyl substituents with two or more carbon atoms, such as ethyl and propyl groups. Such feed components undergo disproportionation at operating conditions to produce C 10+ coke precursors. Unsaturated species liberated by dealkylation can further react with the transalkylation catalyst, producing carbon deposits that block access of other reactants to the active sites on the catalyst. One solution involves in-situ removal of unsaturated species by hydrogenation. Ideally, a hydrogenation catalyst would fully saturate unsaturated species to the corresponding alkane while minimizing ring saturation of aromatic components. However, problems exist with catalyst selectivity at operating conditions, which can result in hydrogenation of aromatic species, thereby reducing yields and making separation more difficult. Noble metals on zeolite / binder blends can be the primary catalyst choice for hydrogenation activity, but metals such as Pt typically cannot selectively remove olefins without causing some ring saturation. One solution involves adding additional metals to the catalyst, thereby reducing aromatic ring hydrogenation, but such catalysts containing two or more metals typically exhibit lower overall catalytic activity and can still produce product species with some ring saturation. Summary of the Invention [Problem to be solved by the invention]

[0005] This application relates to catalyst systems for converting C9+ aromatics to lighter aromatics, and in particular, embodiments relate to catalyst systems configured to hydrogenate light olefins produced by in situ dealkylation of C2+ alkyl species from C9+ aromatics while minimizing hydrogenation of the desired BTX product. [Means for solving the problem]

[0006] Disclosed herein is a catalyst comprising metal functional groups derived from a metal confined in cages and / or channels of a microporous material, the cages and / or channels of the microporous material being defined by 8 or fewer tetrahedral atoms; and acidic functional groups derived from an additional zeolite having cages and / or channels defined by 10 or more tetrahedral atoms, wherein the microporous material providing the metal functional groups and the additional zeolite providing the acidic functional groups are bound together by a binder.

[0007] Further disclosed herein is a process comprising the steps of: introducing a feedstock comprising hydrogen, toluene, and C9+ aromatic hydrocarbons into a reactor, wherein at least a portion of the C9+ aromatic hydrocarbons comprise C2+ alkyl groups; and contacting the feedstock with a catalyst comprising metal functional groups derived from a metal confined in cages and / or channels of a microporous material, the cages and / or channels of the microporous material being defined by 8 or fewer tetrahedral atoms; and acidic functional groups derived from an additional zeolite having cages and / or channels defined by 10 or more tetrahedral atoms, wherein the microporous material providing the metal functional groups and the additional zeolite providing the acidic functional groups are bound together by a binder, and the catalyst is effective for dealkylating at least a portion of the C9+ aromatic hydrocarbons comprising the C2+ alkyl groups to produce corresponding olefins and C9+ aromatic hydrocarbons, and hydrogenating at least a portion of the corresponding olefins to form corresponding alkanes.

[0008] Further disclosed herein is a process comprising the steps of contacting an aromatic hydrocarbon feedstock with a catalyst composition comprising metal functional groups derived from a metal confined within the cages and / or channels of a microporous material, the cages and / or channels of the microporous material being defined by 8 or fewer tetrahedral atoms, and acidic functional groups derived from an additional zeolite having channels defined by 10 or more tetrahedral atoms, wherein the microporous material providing the metal functional groups and the additional zeolite providing the acidic functional groups are bound by a binder, the aromatic hydrocarbon feedstock comprising toluene and C9+ aromatic hydrocarbons, at least a portion of which comprise C2+ alkyl groups; dealkylating at least a portion of the C9+ aromatic hydrocarbons comprising C2+ alkyl groups to form corresponding C2+ olefins and C9+ aromatic hydrocarbons; saturating at least a portion of the formed C2+ olefins to produce corresponding C2+ alkanes; and transalkylating at least a portion of the C9+ aromatic hydrocarbons with toluene to form xylenes.

[0009] These drawings illustrate certain aspects of the invention and should not be used to limit or define the invention. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram illustrating one embodiment of a transalkylation process. DETAILED DESCRIPTION OF THE INVENTION

[0011] This application relates to catalyst systems for converting C aromatics to lighter aromatics, and in particular, embodiments relate to catalyst systems configured to hydrogenate light olefins produced by in situ dealkylation of C alkyl species from C aromatics while minimizing ring loss in the desired BTX product. While the methods and systems disclosed herein may be suitable in stand-alone units, these methods and systems may be particularly suitable for integrated processes within a refinery or chemical plant.

[0012] As discussed above, a common source of BTX in refineries and chemical plants can be obtained by the reaction of naphtha feedstock. Naphtha feedstock can be reacted to form a C6+ aromatic stream, including benzene, toluene, and xylenes, as well as alkyl-substituted aromatic species thereof. However, the methods described herein can be used with any C6+ aromatic stream. In some examples, the present disclosure may refer to C6+, C7+, C8+, and C9+ streams and components. As used herein, the term "Cn+" (where n is a positive integer) refers to a compound or group containing at least n carbon atoms. Additionally, the term "Cn+ aromatics" (where n is a positive integer) refers to a stream or stream component containing aromatic hydrocarbons having at least n carbon atoms per molecule. For example, a C6+ stream can include molecules having 6 or more carbon atoms per molecule, e.g., 6, 7, 8, 9, 10, or more, and a C9+ stream can include molecules having 9 or more carbon atoms per molecule, e.g., 9, 10, or more. The exact composition of the C6+ stream can be determined by the composition of the reacted naphtha and the process conditions under which the naphtha is reacted. Some specific C6+ aromatics can include, but are not limited to, benzene, toluene, xylene, 1,3,5-trimethylbenzene, 1,2,4,5-tetramethylbenzene, 1,2,4-trimethylbenzene, 1,2,4-trimethylbenzene, ethyltoluene, ethylxylene, propyl-substituted benzenes, butyl-substituted benzenes, and dimethylethylbenzene. In addition to the catalytic reforming and steam cracking processes mentioned above, the C6+ aromatics can be obtained from any aromatics-rich refinery process, such as FCC naphtha or TCC naphtha.

[0013] A process for producing xylenes by transalkylation of a C9+ aromatic hydrocarbon feedstock with C6 and / or C7 aromatic hydrocarbons includes the steps of: (a) contacting a C9+ aromatic hydrocarbon feedstock, at least one C6 and / or C7 aromatic hydrocarbon, and hydrogen with a catalyst under conditions effective to dealkylate at least a portion of the C9+ aromatic hydrocarbons in the feedstock that contain C2+ alkyl groups to form corresponding C9+ aromatic hydrocarbons and corresponding C2+ olefins, saturate the formed C2+ olefins, and transalkylate the C9+ aromatic hydrocarbons with at least one C6-C7 aromatic hydrocarbon to form an effluent comprising xylenes.

[0014] The diagram illustrates an exemplary process 100 in which a C aromatic feedstock is transalkylated to form xylenes. Process 100 can begin by introducing a feedstock 102 containing C hydrocarbons into a fractionator 104. Feedstock 102 can include, for example, any of the C hydrocarbons disclosed herein. In fractionator 104, the hydrocarbons in feedstock 102 can be fractionated to produce a benzene product stream 106, which can include a majority of the benzene present in feedstock 102. Fractionator 104 can further fractionate feedstock 102 into a toluene stream 108 and a C stream 110. Toluene stream 108 can include a majority of the toluene present in feedstock 102, and C stream 110 can include a majority of the C components in feedstock 102. Although fractionator 104 is shown in the figure as a single distillation column, fractionator 104 may comprise a distillation train including multiple distillation columns to produce benzene product stream 106, toluene stream 108, and C9+ stream 110.

[0015] The C9+ stream 110 from fractionator 104 may be combined with a xylene recycle stream 132 and introduced into fractionator 118. The feed to fractionator 118 may include a majority of the C9+ compounds from feed 102 and a majority of the recycled xylenes from xylene isomerization unit 130, as described below. Fractionator 118 may separate the components to produce a xylene-rich stream 120, a C9+ aromatics stream 122, and optionally a C11+ aromatics stream 134. The xylene-rich stream 120 may include a majority of the C8 and lighter hydrocarbons from the feed to fractionator 118. The C9+ aromatics stream 122 may include a majority of the hydrocarbons having a carbon number in the C9 to C10 range from the feed to fractionator 118. The C11+ aromatics stream 134 may include the remainder of the hydrocarbon feed to fractionator 118 and may include hydrocarbons having a carbon number of C11+. Although fractionator 118 is shown as a single distillation column in the figure, fractionator 118 may comprise a distillation train including multiple distillation columns to produce xylene-rich stream 120, C9+ aromatics stream 122, and C11+ aromatics stream 134.

[0016] The xylene-rich stream 120 from the fractionator 118 can be introduced into a xylene separation unit 124, which can include equipment that separates the xylene-rich stream 120 into a xylene product stream 126. The xylene product stream 126 can include separate product streams of o-xylene, m-xylene, and p-xylene. Distillation or another separation unit operation can be used to separate the o-xylene, m-xylene, and p-xylene streams, which can then be used, for example, in downstream processes. Because p-xylene is generally the more desirable isomer, additional chemical processes can be used to increase the yield of p-xylene. In some examples, a xylene isomerization stream 128 containing o-xylene and m-xylene can be recovered in the xylene separation unit 124 and introduced into a xylene isomerization unit 130, which can include a reactor containing a catalyst capable of catalyzing xylene isomerization. The xylene recycle stream 132 exiting the xylene isomerization unit 130 may include a mixture of o-xylene, m-xylene, and p-xylene.

[0017] The C9+ aromatics stream 122 from the fractionator 118 can be mixed with the toluene stream 108 to form a heavy aromatics stream 136, which can be introduced into the transalkylation unit 114. The transalkylation unit 114 can include a reactor having a catalyst, such as a catalyst described herein, capable of catalyzing the dealkylation of aromatic hydrocarbons containing C2+ alkyl groups and saturating the formed C2+ olefins. The catalyst used in the transalkylation unit 114 can be more effective at transalkylating the C9+ aromatic hydrocarbons with C6-C7 aromatic hydrocarbons to produce xylenes. The hydrogen stream 112 can be introduced into the transalkylation unit 114 to provide a hydrogen source for saturating the C2+ olefins formed during the dealkylation. The transalkylation effluent stream 116 from the transalkylation unit 114 can be mixed with the feedstock 102 and then introduced into the fractionator 104. The transalkylation effluent stream 116 can include, for example, benzene, toluene, and mixed xylenes, as well as unreacted C9+ aromatic hydrocarbons.

[0018] The transalkylation unit 144 may include a single-bed catalyst system or may include a multi-bed catalyst system to produce xylenes. When the catalyst system contacts the heavy aromatic stream 136, the catalyst system may include at least one, two, or possibly three catalyst beds, such that a first catalyst bed may be located upstream of a second catalyst bed and, if present, a third catalyst bed may be located downstream of the second catalyst bed. The first catalyst bed, including the first catalyst, may be effective for dealkylating aromatic hydrocarbons in the heavy aromatic stream 136 that include C2+ alkyl groups and saturating the resulting C2+ olefins, while the second catalyst bed is effective for transalkylating C9+ aromatic hydrocarbons with C7-C8 aromatic hydrocarbons to produce xylenes. The optional third catalyst bed may be effective for cracking non-aromatic cyclic hydrocarbons in the effluent from the first and second catalyst beds.

[0019] The transalkylation unit can be operated at a temperature ranging from about 32°F (0°C) to about 1110°F (600°C). Alternatively, the transalkylation unit can be operated at a temperature ranging from about 32°F (0°C) to about 100°F (38°C), from about 100°F (38°C) to about 200°F (93°C), from about 200°F (93°C) to about 300°F (149°C), from about 300°F (149°C) to about 400°F (204°C), from about 400°F (204°C) to about 500°F (260°C), or from about 500°F (206°C) to about 600°F. F (316°C), about 600°F (316°C) to about 700°F (371°C), about 700°F (371°C) to about 800°F (427°C), about 800°F (427°C) to about 900°F (482°C), about 900°F (482°C) to about 1000°F (538°C), or about 1000°F (538°C) to about 1110°F (599°C). The transalkylation unit can be operated at any pressure ranging from about atmospheric pressure (14.7 psia 101.325 kPa) to about 1400 psi (6952 kPa). Alternatively, the transalkylation unit can be operated at a pressure ranging from about 14.7 psi (101.325 kPa) to about 250 psi (1725 kPa), from about 250 psi (1725 kPa) to about 500 psi (3447 kPa), from about 500 psi (3447 kPa) to about 750 psi (5171 kPa), from about 750 psi (5171 kPa) to about 1000 psi (6895 kPa), from about 1000 psi (6895 kPa) to about 1200 psi (8274 kPa), or from about 1200 psi (8274 kPa) to about 1400 psi (9653 kPa).

[0020] The catalyst can include metal functional groups derived from a metal confined within the cages or channels of the microporous material and acidic functional groups derived from the additional zeolite. The acidic functional groups of the zeolite can enable the catalyst to catalyze dealkylation reactions, such as the dealkylation of aromatic hydrocarbons containing C2+ alkyl groups to the corresponding aromatic hydrocarbons and C2+ olefins. The metal functional groups can enable the catalyst to catalyze hydrogenation reactions, such as the hydrogenation of C2+ olefins to their corresponding alkanes. The cages or channels of the microporous material can be defined by eight or fewer tetrahedral atoms. As described in more detail below, microporous materials containing cages or channels of eight or fewer tetrahedral atoms can exhibit size exclusion properties, whereby relatively large molecules cannot diffuse into the microporous material and react with the metal functional groups. This size exclusion can increase the selectivity of hydrogenation of C2+ olefins produced by dealkylation of aromatic hydrocarbons containing C2+ alkyl groups and decrease the selectivity of hydrogenation of aromatic rings. In some examples, the additional zeolite can have channels defined by 10 or more tetrahedral atoms. In a further example, the microporous material and the additional zeolite may be bound together by a binder.

[0021] Microporous materials can include any material containing cages or channels that may be defined by eight tetrahedral atoms and / or have cages or channels defined by a kinetic diameter of 5.85 angstroms or less, which may be the largest measurement of the cage or channel. Some suitable microporous materials include, but are not limited to, AEI, AFT, AFX, CHA, CDO, DDR, EDI, ERI, IHW, ITE, ITQ-55, ITW, KFI, MER, MTF, MWF, LEV, LTA, PAU, PWY, RHO, SOD, SFW, UFI, and combinations thereof. Microporous materials can include a metal, such as a metal selected from Groups 6-12 of the Periodic Table of the Elements, at least partially disposed within the cages or channels of the microporous material. Some exemplary metals include, but are not limited to, platinum, palladium, gallium, iridium, rhenium, copper, silver, gold, ruthenium, rhodium, iron, tungsten, molybdenum, cobalt, nickel, and combinations thereof. In some examples, two metals may be selected, with the second metal being selected to have a lower benzene saturation activity than the first metal. The metal may be present in the catalyst in an amount between about 0.001% and about 5% by weight of the catalyst. Alternatively, the metal may be present in an amount between about 0.001% and about 0.010%, about 0.010% and about 0.1%, about 0.1% and about 1%, or about 1% and about 5% by weight of the catalyst. Additionally, the microporous material may be present in any suitable amount in the catalyst. For example, the microporous material may be present in an amount between about 1% and about 90% by weight, based on the weight of the catalyst. Alternatively, the microporous material can be present in an amount of about 1% to about 10% by weight, about 10% to about 30% by weight, about 30% to about 50% by weight, about 50% to about 70% by weight, about 70% to about 90% by weight, or any range therebetween.

[0022] The additional zeolite can be any acidic zeolite, some suitable acidic zeolites include, but are not limited to, MFI, MAZ, MEL, MTW, MEI, EMT, TON, MTT, FER, MRE, MFS, DDR, EWT, BET, USY, NES, EMM, MWW, MOR, and MSE. Some specific zeolites include, but are not limited to, ZSM-3, ZSM-4, ZSM-5, ZSM-11, ZSM-12, ZSM-18, ZSM-20, ZSM-22, ZSM-23, ZSM-35, ZSM-48, ZSM-57, ZSM-58, EMM-10, EMM-34, zeolite beta, zeolite Y, ultrastable Y (USY), dealuminated Y, mordenite, NU-87, MCM-22, MCM-68, PSH-3, SSZ-25, MCM-36, MCM-49, MCM-56, UZM-14, and combinations thereof. In some examples, the additional zeolite can have channels defined by 10 or more tetrahedral atoms. The additional zeolite can be present in the catalyst in any suitable amount. For example, the additional zeolite material can be present in an amount of about 1% to about 90% by weight, based on the weight of the catalyst, or the additional zeolite can be present in an amount of about 1% to about 10%, about 10% to about 30%, about 30% to about 50%, about 50% to about 70%, about 70% to about 90%, or any range therebetween.

[0023] The catalyst can further include a molecular sieve. Some molecular sieves include, but are not limited to, MFI, MAZ, MEL, MTW, MEI, EMT, TON, MTT, FER, MRE, MFS, DDR, EWT, BET, USY, and NES. Some specific zeolites include, but are not limited to, ZSM-5, ZSM-11, ZSM-22, ZSM-23, ZSM-35, ZSM-48, ZSM-57, ZSM-58, and EMM-34. The molecular sieve can have any particle size suitable for a particular application. The molecular sieve can be present in the catalyst in any suitable amount. For example, the molecular sieve material can be present in an amount of about 1 wt % to about 90 wt % based on the weight of the catalyst. Alternatively, the molecular sieve can be present in an amount of about 1% to about 10% by weight, about 10% to about 30% by weight, about 30% to about 50% by weight, about 50% to about 70% by weight, about 70% to about 90% by weight, or any range therebetween.

[0024] The catalyst may further comprise a binder or matrix material capable of compounding or otherwise binding the individual components of the catalyst together. Such materials may include active and inactive materials, as well as inorganic materials such as synthetic or natural zeolites, clays, silica, and / or metal oxides such as alumina. The inorganic materials may be natural or in the form of gelatinous precipitates or gels, such as mixtures of silica and metal oxides. Binder or matrix materials that are catalytically active themselves may alter the conversion and / or selectivity of the catalyst composition. Inert materials suitably function as diluents to control the amount of conversion so that transalkylation products can be obtained without the use of additional means to control the reaction rate. These catalytically active or inactive materials may include, for example, natural clays, such as bentonite and kaolin, to improve the compressive strength of the catalyst composition under industrial operating conditions.

[0025] Natural clays that can be composited with the microporous material and additional zeolite include, for example, clays from the montmorillonite and kaolin classes, which include subbentonite and kaolins known as Dixie clays, McNamee clays, Georgia clays, and Florida clays, where the primary inorganic component is halloysite, kaolinite, dickite, nacrite, or anauxite. Such clays can be used in their original, raw, mined state or after first being calcined, acid-treated, or chemically modified.

[0026] In addition to the aforementioned materials, the catalyst can include a binder material such as an inorganic oxide selected from the group consisting of silica, alumina, zirconia, titania, thoria, beryllia, magnesia, and combinations thereof, e.g., silica-alumina, silica-magnesia, silica-zirconia, silica-thoria, silica-beryllia, silica-titania, and ternary compositions, e.g., silica-alumina-thoria, silica-alumina-zirconia, silica-alumina-magnesia, and silica-magnesia-zirconia. It can also be advantageous to provide at least a portion of the porous matrix binder material in colloidal form to facilitate extrusion of the catalyst composition. In some examples, the microporous material and additional zeolite can be mixed with the binder or matrix material such that the first catalyst composition includes the binder or matrix material in an amount ranging from about 1 wt % to about 90 wt %, based on the weight of the catalyst. Alternatively, the binder or matrix material can be present in an amount of about 1% to about 10% by weight, about 10% to about 30% by weight, about 30% to about 50% by weight, about 50% to about 70% by weight, about 70% to about 90% by weight, or any range therebetween.

[0027] As discussed above, the catalyst can include a microporous material having a metal confined within the cages or channels of the microporous material. Metal-containing microporous materials can be prepared by any suitable method, such as by cocrystallization, exchange into the microporous material, impregnation, or mixing with the microporous material and binder. In some examples, the metal component can be impregnated into or onto the microporous material by treating the microporous material with a solution containing a Group 6-12 element. Platinum can be added to the microporous material by contacting the microporous material with a solution containing platinum metal-containing ions. Platinum compounds suitable for impregnating microporous materials with platinum include chloroplatinic acid, platinous chloride, and various compounds containing platinum ammine complexes, such as Pt(NH3)4Cl2H2O, nitrates, and hydroxides. After incorporating the metal components, the microporous material can be dried by heating at a temperature of 65°C to 160°C, typically 110°C to 143°C, for at least 1 minute, generally within 24 hours, at a pressure of 100 to 200 kPa-a. The microporous material can then be calcined in a flow of dry gas, such as air or nitrogen, at a temperature of 260°C to 650°C for 1 to 20 hours. Calcination is typically carried out at a pressure in the range of 100 to 300 kPa-a.

[0028] Thus, the above description describes a catalytic system for converting C aromatics to lighter aromatics. The systems and methods disclosed herein can include any of the various features disclosed herein, such as one or more of the following embodiments.

[0029] Embodiment 1. A catalyst comprising metal functional groups derived from a metal confined in cages and / or channels of a microporous material, the cages and / or channels of the microporous material being defined by 8 or fewer tetrahedral atoms; and acidic functional groups derived from an additional zeolite having cages and / or channels defined by 10 or more tetrahedral atoms, wherein the microporous material providing the metal functional groups and the additional zeolite providing the acidic functional groups are bound together by a binder.

[0030] Embodiment 2. The catalyst of embodiment 1, wherein the microporous material is selected from the group consisting of AEI, AFT, AFX, CHA, CDO, DDR, EDI, ERI, IHW, ITE, ITQ-55, ITW, KFI, MER, MTF, MWF, LEV, LTA, PAU, PWY, RHO, SOD, SFW, UFI, and combinations thereof.

[0031] Embodiment 3. The catalyst of any of embodiments 1-2, wherein the metal is selected from the group consisting of platinum, palladium, gallium, iridium, rhenium, copper, silver, gold, ruthenium, rhodium, iron, tungsten, molybdenum, cobalt, nickel, and combinations thereof.

[0032] Embodiment 4. The catalyst of any of embodiments 1-3, wherein at least 80% by weight of the metal is confined within the cages and / or channels of the microporous material, and at least 80% by weight of the metal is confined within the cages or channels of the microporous material.

[0033] Embodiment 5. The catalyst of any of embodiments 1-4, wherein the additional zeolite is selected from the group consisting of MFI, MAZ, MEL, MTW, MEI, EMT, TON, MTT, FER, MRE, MFS, DDR, EWT, BET, USY, NES, EMM, MWW, MOR, MSE, and combinations thereof.

[0034] Embodiment 6. The microporous material is chabazite. (chabazite) 6. The catalyst of any of embodiments 1-5, wherein the metal comprises platinum and the additional zeolite comprises at least one of MFI, MEL, or MOR.

[0035] Embodiment 7. The catalyst of any of embodiments 1-6, further comprising a binder selected from the group consisting of an alumina binder, a silica binder, and combinations thereof, wherein the binder is present in an amount of about 1 wt % to about 20 wt %, based on the weight of the catalyst.

[0036] Embodiment 8. A method comprising the steps of introducing a feedstock comprising hydrogen, toluene, and C9+ aromatic hydrocarbons into a reactor, wherein at least a portion of the C9+ aromatic hydrocarbons comprise C2+ alkyl groups; and contacting the feedstock with a catalyst comprising metal functional groups derived from a metal confined in cages and / or channels of a microporous material, the cages and / or channels of the microporous material being defined by 8 or fewer tetrahedral atoms, and acidic functional groups derived from an additional zeolite having cages and / or channels defined by 10 or more tetrahedral atoms, wherein the microporous material providing the metal functional groups and the additional zeolite providing the acidic functional groups are bound by a binder, and the catalyst is effective for dealkylating at least a portion of the C9+ aromatic hydrocarbons comprising the C2+ alkyl groups to produce corresponding olefins and C9+ aromatic hydrocarbons, and hydrogenating at least a portion of the corresponding olefins to form corresponding alkanes.

[0037] Embodiment 9. The method of embodiment 8, wherein the microporous material is selected from the group consisting of AEI, AFT, AFX, CHA, CDO, DDR, EDI, ERI, IHW, ITE, ITQ-55, ITW, KFI, MER, MTF, MWF, LEV, LTA, PAU, PWY, RHO, SOD, SFW, UFI, and combinations thereof.

[0038] Embodiment 10. The method of any of embodiments 8-9, wherein the metal is selected from the group consisting of platinum, palladium, gallium, iridium, rhenium, copper, silver, gold, ruthenium, rhodium, iron, tungsten, molybdenum, cobalt, nickel, and combinations thereof.

[0039] Embodiment 11. The method of any of embodiments 8-10, wherein the additional zeolite is selected from the group consisting of MFI, MAZ, MEL, MTW, MEI, EMT, TON, MTT, FER, MRE, MFS, DDR, EWT, BET, USY, NES, EMM, MWW, MOR, MSE, and combinations thereof.

[0040] Embodiment 12. The method of any of embodiments 8-11, wherein the catalyst is further effective for transalkylating toluene and C9+ aromatic hydrocarbons to form xylenes.

[0041] Embodiment 13. The method of any of embodiments 8-12, wherein the microporous material comprises chabazite, the metal comprises platinum, and the additional zeolite comprises at least one of MFI, MEL, or MOR.

[0042] Embodiment 14. A process comprising the steps of contacting an aromatic hydrocarbon feedstock with a catalyst composition comprising metal functional groups derived from a metal confined in the cages and / or channels of a microporous material, the cages and / or channels of the microporous material being defined by 8 or fewer tetrahedral atoms, and acidic functional groups derived from an additional zeolite having channels defined by 10 or more tetrahedral atoms, wherein the microporous material providing the metal functional groups and the additional zeolite providing the acidic functional groups are bound by a binder, and the aromatic hydrocarbon feedstock comprises toluene and C9+ aromatic hydrocarbons, at least a portion of which comprise C2+ alkyl groups; dealkylating at least a portion of the C9+ aromatic hydrocarbons comprising C2+ alkyl groups to form corresponding C2+ olefins and C9+ aromatic hydrocarbons; saturating at least a portion of the formed C2+ olefins to produce corresponding C2+ alkanes; and transalkylating at least a portion of the C9+ aromatic hydrocarbons with toluene to form xylenes.

[0043] Embodiment 15. The method of embodiment 14, wherein the microporous material is selected from the group consisting of AEI, AFT, AFX, CHA, CDO, DDR, EDI, ERI, IHW, ITE, ITQ-55, ITW, KFI, MER, MTF, MWF, LEV, LTA, PAU, PWY, RHO, SOD, SFW, UFI, and combinations thereof.

[0044] Embodiment 16. The method of any of embodiments 14-15, wherein the metal is selected from the group consisting of platinum, palladium, gallium, iridium, rhenium, copper, silver, gold, ruthenium, rhodium, iron, tungsten, molybdenum, cobalt, nickel, and combinations thereof.

[0045] Embodiment 17. The method of any of embodiments 14-16, wherein the additional zeolite is selected from the group consisting of MFI, MAZ, MEL, MTW, MEI, EMT, TON, MTT, FER, MRE, MFS, DDR, EWT, BET, USY, NES, EMM, MWW, MOR, MSE, and combinations thereof.

[0046] Embodiment 18. The method of any of embodiments 14-17, wherein the microporous material comprises chabazite, the metal comprises platinum, and the additional zeolite comprises at least one of MFI, MEL, or MOR.

[0047] Embodiment 19. The method of any of embodiments 14-18, further comprising separating at least a portion of the xylenes to form a xylene-rich stream.

[0048] Embodiment 20. The process of any of embodiments 14-19, wherein the aromatic hydrocarbon feedstock further comprises hydrogen. [Example]

[0049] To facilitate a better understanding of the present invention, the following examples of specific aspects of some embodiments are provided. The following examples should in no way be read as limiting or determining the overall scope of the invention.

[0050] Example 1 In this example, precious metals encapsulated in small-pore chabazite (CHA) were prepared. First, 800 mg of sodium hydroxide was dissolved in 6.9 g of water. Next, 86 mg of an 8 wt % aqueous solution of chloroplatinic acid (37.5 wt % based on HPtClPt) and 52 mg of 3-mercaptopropyltrimethoxysilane (TMSH) were added to the sodium hydroxide solution and stirred for approximately 30 minutes. Then, 13.04 g of a 16.2 wt % aqueous solution of N,N,N-trimethyl-l-adamantammonium hydroxide (TMAdA) in water was added and stirred for approximately 15 minutes. After approximately 15 minutes, 293 mg of aluminum hydroxide (58 wt %) was added, and the resulting mixture was stirred at approximately 80°C for approximately 30 minutes. Then, 3 g of colloidal silica was added to the mixture and stirred at 80°C for 30 minutes. The final gel composition was found to be SiO2:0.033 Al2O3:0.00033 Pt:0.005 TMSH:0.2 TMAdA:0.4 NaOH:20 H2O. The gel was transferred to an autoclave with a PTFE liner and heated under dynamic conditions at approximately 90 °C for approximately 7 days, followed by approximately 160 °C for approximately 2 days. The hydrothermally crystallized sample was filtered, washed with copious amounts of distilled water, and finally dried at 100 °C. To remove organic moieties contained within the microporous material during the crystallization process, the Pt-containing CHA was calcined in air at 550 °C. The calcined sample was then treated with H2 at 400 °C for 2 hours.

[0051] Example 2 In this example, EMM-34 zeolite was prepared. A mixture was prepared from 9300 g of water, 804 g of tetraethylammonium bromide (TEABr) (50 wt. % solution), 2750 g of silica, 584 g of sodium aluminate solution (45 wt. %), and 612 g of 50 wt. % sodium hydroxide solution. Then, 30 g of mordenite seed crystals were added to the mixture. The mixture was reacted in an autoclave at about 143°C with stirring for about 72 hours. The product was filtered, washed with deionized water, and dried at about 121°C. The as-synthesized crystals were calcined in nitrogen at about 538°C and converted to the hydrogen form by ion-exchange three times with ammonium nitrate solution at room temperature, followed by drying at about 121°C and calcination at about 540°C for about 6 hours. The resulting EMM-34 had a SiO2 / Al2O3 molar ratio of about 21 and a surface area of ​​637 m2. 2 / g and mesopore surface area of ​​56 m 2 / g.

[0052] Example 3 In this example, ZSM-11 zeolite was prepared. A mixture was prepared from 8250 g of water, 1540 g of 50 wt% tetra-n-butylammonium bromide (TBABr) solution, 2750 g of silica, 1010 g of 47 wt% aluminum sulfate solution, 880 g of 50 wt% sodium hydroxide solution, and 30 g of ZSM-11 seed crystals. This mixture was reacted in an autoclave at 121 °C with stirring for approximately 72 hours. The resulting product was filtered, washed with deionized water, and dried at 121 °C. The as-synthesized crystals were converted to the hydrogen form by ion exchange three times with ammonium nitrate solution at room temperature, followed by drying at 120 °C and calcination at 540 °C for 6 hours. The resulting ZSM-11 crystals had a SiO2 / Al2O3 molar ratio of approximately 50 and a total surface area (SA) / (micropore SA + mesopore SA) of 481 / (364 + 117) m2. 2 / g.

[0053] Example 4 In this example, ZSM-5 zeolite was prepared. A first mixture was prepared from 22.0 grams of SiO partially dissolved in 100 mL of 2.18 N tetrapropylammonium hydroxide by heating to a temperature of approximately 100°C. A second mixture of 3.19 grams of NaAlO (analyzed to contain 42.0 wt.% AlO, 30.9 wt.% NaO, and 27.1 wt.% HO) was then dissolved in 53.8 mL of HO. The first and second mixtures were mixed and found to have a composition of 0.382 moles of SiO, 0.0131 moles of AlO, 0.0159 moles of NaO, 0.118 moles of CHCHCHNO, and 6.30 moles of HO. This combined mixture was placed in a borosilicate-lined autoclave and heated at approximately 150°C for approximately 6 days. The resulting solid product was cooled to room temperature, removed, filtered, washed with 1 liter of HO, and dried at about 110° C. The as-synthesized crystals were pre-calcined at 538° C. in nitrogen and then converted to the hydrogen form by ion-exchanging three times with ammonium nitrate solution at room temperature, followed by drying at about 121° C. and calcining at about 540° C. for about 6 hours.

[0054] Example 5 In this example, an EMM-34 / ZSM-11 / alumina catalyst support was prepared. A catalyst support powder was prepared by mixing 44 parts of the EMM-34 crystals from Example 2, 36 parts of the ZSM-11 from Example 3, and 20 parts of alumina in a muller. Sufficient water was added to form an extrudable paste. This mixture of EMM-34, ZSM-11, alumina, and water was extruded into 1 / 16-inch (1.5875 mm) cylinders and then dried overnight in an oven at 121°C. The dried extrudates were pre-calcined in nitrogen at 538°C to decompose and remove the organic template. The pre-calcined extrudates were then humidified with saturated air at ambient conditions for 1 hour. After humidification, the extrudates were exchanged with 1N ammonium nitrate to remove sodium. The extrudates were then washed with deionized water and dried at 121°C for at least 4 hours. The resulting material was then calcined in air at 538°C.

[0055] Example 6 In this example, a first catalyst is prepared by adding Pt encapsulated in CHA to the support of Example 5. 75 parts of the 44 / 36 / 20 EMM-34 / ZSM-11 / alumina catalyst from Example 5 and 25 parts of 0.2 wt. % Pt encapsulated in small pore CHA from Example 1 were mixed in a rotary mill, pressed, and sieved to a 1000-1410 μm particle size.

[0056] Example 7 In this example, a second catalyst was prepared. First, 44 parts of the EMM-34 crystals from Example 2, 36 parts of the ZSM-11 from Example 3, and 20 parts of alumina were mixed in a muller. A solution of tetraammineplatinum chloride and tin(II) chloride dehydrate in water was added to the muller and then formed into a target loading of 0.03 wt. % Pt and 0.11 wt. % Sn for the final extrusion. This mixture of EMM-34, ZSM-11, alumina, and water was extruded into 1 / 16-inch (1.5875 mm) cylinders and then dried overnight in an oven at 121°C. The dried extrudates were precalcined at 538°C in nitrogen. The extrudates were then washed with deionized water and dried at 121°C for at least 4 hours. The resulting material was calcined in air at 538°C.

[0057] Example 8 In this example, a third catalyst was prepared. First, 44 parts of the EMM-34 crystals from Example 2, 36 parts of the ZSM-11 from Example 3, and 20 parts of silica were mixed in a muller. An aqueous solution of tetraammineplatinum chloride and tin(II) chloride dehydrate in water was added to the muller and then formed into a target loading of 0.03 wt. % Pt and 0.11 wt. % Sn for the final extrusion. This EMM-34, ZSM-11, silica, and water mixture was extruded into 1 / 16-inch (1.5875 mm) cylinders and then dried overnight in an oven at 121°C. The dried extrudates were pre-calcined at 538°C in nitrogen to decompose and remove the organic template. The pre-calcined extrudates were then humidified with saturated air at ambient conditions for 1 hour. After humidification, the extrudates were exchanged with 1N ammonium nitrate to remove sodium. The extrudates were then washed with deionized water and then dried for at least 4 hours at 121° C. The resulting material was then calcined in air at 538° C.

[0058] Example 9 In this example, a fourth catalyst was prepared. Fifty parts of the EMM-34 crystals from Example 2 were mixed with 20 parts of the ZSM-5 crystals from Example 4 and 30 parts of alumina in a muller. Aqueous solutions of tetraammineplatinum chloride and gallium(III) nitrate were added to the muller and then formulated to a target loading for the final extrusion of 0.03 wt. % Pt and 0.032 wt. % Ga. The EMM-34, ZSM-5, alumina, and water mixture was extruded into 1 / 16-inch (1.5875 mm) cylinders and dried at 121°C in a conveyor convection oven for several hours. The dried extrudates were precalcined at 538°C in nitrogen to decompose and remove the organic template. The precalcined extrudates were then humidified with saturated air at ambient conditions for 1 hour. After humidification, the extrudates were exchanged with 1N ammonium nitrate to remove sodium. The extrudates were then washed with deionized water and then dried for at least 4 hours at 121° C. The resulting material was then calcined in air at 538° C.

[0059] Example 10 This example tests the catalysts prepared in the previous examples. Examples 6-9 were evaluated in a parallel microunit using a blend of 60% C9+ heavy aromatic feed and 40% toluene, fed with hydrogen. The feed composition is shown in Table 1. First, 2 grams of each catalyst prepared in Examples 6-9 was sieved to 14-18 mesh (1000-1410 μm) and loaded into a reactor along with an equal part by weight of quartz. The catalyst was first activated by heating in hydrogen at 400°C for 2 hours. The catalyst was then cooled to 350°C, at which point the feed blend was introduced (unless otherwise noted). The reactor pressure was 390 psig (26.9 bar), and the heavy aromatic feed to hydrogen ratio was 2. The composition of the product exiting the reactor was analyzed using FID-GC after separation of the components on a 60 m DB-1 column. The experimental results are shown in Tables 2 and 3. In Table 2, ring reduction was calculated using Equation 1.

number

[0060] [Table 1]

[0061] [Table 2]

[0062] [Table 3]

[0063] The above examples show that the catalyst of Example 6, which contains a small pore CHA that encapsulates the metal, is (Comparative Example)Catalyst 6 has the lowest C6+ non-aromatics (associated with high benzene purity) compared to catalysts 7-9. Because bulkier hydrocarbons (e.g., aromatics) cannot diffuse into the pores of the small pore zeolite (e.g., CHA) where the metal functional groups are located, ring saturation does not occur (hence the low C6+ non-aromatics shown in Figure 1). Similarly, ring reduction by the catalyst of Example 6 is significantly higher than that of the catalysts of Examples 7-9. (Comparative Example) The ethane / ethylene ratio of the catalyst of Example 6 is lower than that of the other catalysts of Examples 7 to 9. (Comparative Example) 1.7 times that of catalyst 7, Example (Comparative Example) 8 This is 3.5 times the catalyst of Example (Comparative Example) The catalyst was 6.3 times that of Example 9. (Comparative Example) 7 This is because the catalyst composition of the catalyst of Example 6 does not contain a second metal that would adversely affect the hydrogenation activity of the noble metal, as was the case with catalysts 1 to 9. Therefore, the catalyst of Example 6 selectively hydrogenates ethylene (e.g., obtained by dealkylation of ethyltoluene) in the presence of aromatic compounds, while maintaining high hydrogenation activity of the noble metal.

[0064] The ethyl-aromatic conversion of the catalyst of Example 6 containing the metal-encapsulated small-pore CHA was confirmed to be equivalent to that of the catalyst of Example 7, higher than that of the catalyst of Example 9, and lower than that of the catalyst of Example 8. The trend in ethyl-aromatic conversion is consistent with the trend in ethane production, where higher ethyl-aromatic conversions are associated with higher ethane production. The propyl-aromatic conversion of the catalyst of Example 6 was equivalent to that of the catalysts of Examples 7-9. The catalyst of Example 6 was confirmed to produce less propane than the catalysts of Examples 7-9 at higher propyl-aromatic conversions. Propane production was further improved at higher temperatures, with the catalyst of Example 6 producing approximately two-thirds the propane produced by the catalysts of Examples 7-8, while maintaining high propyl-aromatic conversions. Furthermore, the catalyst of Example 6 produced less isobutane than the catalysts of Examples 7-9. These results are consistent with the idea that the metal-encapsulated Cat of Example 6 exhibits significantly less hydrocarbon cracking than the catalysts of Examples 7-9.

[0065] While the present invention has been described in terms of numerous embodiments and examples, those skilled in the art, having the benefit of this disclosure, will recognize that they may devise other embodiments that do not depart from the scope and spirit of the invention disclosed herein. Although individual embodiments are discussed, the invention extends to all combinations of all such embodiments.

[0066] Although compositions, methods, and processes are described herein in terms of "comprising," "containing," "having," or "including" various components or steps, these compositions and methods may also "consist essentially of" or "consist of" those various components and steps. Unless otherwise specified, the terms "consisting essentially of" and "consisting essentially of" do not exclude the presence of other steps, elements, and materials, whether or not specifically mentioned herein, so long as such steps, elements, or materials do not affect the basic and novel characteristics of the invention, nor do they exclude impurities and variations normally associated with the elements and materials used.

[0067] All numerical values ​​contained in the detailed description and claims herein that are modified by "about" or "approximately" with respect to a stated value are intended to account for experimental error and variations that one of ordinary skill in the art would expect.

[0068] For brevity, only certain ranges are expressly disclosed herein. However, a range from any lower limit can be combined with any upper limit to form an open range, and similarly, a range from any lower limit can be combined with any other lower limit to form an open range, and in the same way, a range from any upper limit can be combined with any other upper limit to form an open range.

Claims

1. a metal functional group derived from a metal confined within cages and / or channels of a microporous material, wherein the cages and / or channels of the microporous material are defined by eight or fewer tetrahedral atoms, the microporous material comprises chabazite, and the metal comprises platinum; acidic functional groups derived from an additional zeolite having cages and / or channels defined by 10 or more tetrahedral atoms, said additional zeolite comprising at least one of MFI, MEL, or MOR; A catalyst comprising: the metal-containing microporous material and the additional zeolite providing the acidic functional groups are bound together by a binder material selected from inorganic oxides; 1. A catalyst, wherein the amount of the microporous material is 10% to 30% by weight based on the weight of the catalyst, the amount of the metal is 0.010% to 0.1% by weight based on the weight of the catalyst, the amount of the additional zeolite is 50% to 70% by weight based on the weight of the catalyst, and the amount of the binder material is 10% to 30% by weight based on the weight of the catalyst.

2. 10. The catalyst of claim 1, wherein at least 80% by weight of the metal is bound within the cages and / or channels of the microporous material.

3. 3. The catalyst of claim 1 or 2, wherein the binder material is selected from the group consisting of silica, alumina, zirconia, titania, thoria, beryllia, magnesia, and combinations thereof.

4. The catalyst of any one of claims 1 to 3, wherein the additional zeolite comprises at least one of ZSM-5, ZSM-11, and EMM-34.

5. introducing a feedstock comprising hydrogen, toluene, and C9+ aromatic hydrocarbons into a reactor, wherein at least a portion of the C9+ aromatic hydrocarbons comprise C2+ alkyl groups; contacting the feedstock with the catalyst of any one of claims 1 to 4; A method comprising:

6. dealkylating at least a portion of the C9+ aromatic hydrocarbons comprising C2+ alkyl groups to form the corresponding C2+ olefins and C9+ aromatic hydrocarbons; saturating at least a portion of the C2+ olefins formed to produce the corresponding C2+ alkanes; transalkylating at least a portion of the C9+ aromatic hydrocarbons with the toluene to form xylenes; Including, The process according to claim 5, wherein the steps of dealkylation, saturation and transalkylation are carried out by means of a catalyst according to any one of claims 1 to 4.

7. 7. The method of claim 6, further comprising separating at least a portion of the xylene to form a xylene-rich stream.

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