Heavy aromatics conversion for increased btx production
By introducing hydrogenation and ring-opening/dealkylation catalysts into the aromatics complex, naphthalene molecules in the heavy aromatics feed stream are converted into BTX precursors, solving the problem of ineffective utilization of C11 and C12 aromatics and achieving increased BTX production and reduced costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- UOP LLC
- Filing Date
- 2024-11-08
- Publication Date
- 2026-06-05
AI Technical Summary
C11 and C12 aromatics were not effectively converted into high-value BTX products in the aromatics complex, resulting in their discharge and waste of resources.
By introducing hydrogenation and ring-opening/dealkylation catalysts into the aromatics complex, naphthalene molecules in the heavy aromatics stream are converted into BTX precursors, and the remaining C11 and C12 monoaromatics are processed in the alkyl transfer reactor to form high-value monoaromatic products.
It increased BTX production, reduced carbon intensity and operating costs, and increased BTX production per ton of feed.
Smart Images
Figure CN122161913A_ABST
Abstract
Description
[0001] Related applications
[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 599,017, filed November 15, 2023, the entire contents of which are incorporated herein by reference. Background Technology
[0003] C 11 and C 12 Aromatic molecules are excellent precursors to p-xylene (pX) because they have a high average methyl to phenyl ratio. Currently, C 11 and C 12 Aromatics are limited by the feedstock of aromatics complexes because they carry coke precursors (i.e., naphthalene molecules). As a result, they are typically used as the basis for C4 formation in naphtha reformers. 11 and C 12 C, the precursor of aromatic hydrocarbons 11 and C 12 Molecules are fed into lower-value feedstreams (such as kerosene, diesel fuel, jet fuel, etc.) instead of being converted into C in naphtha reformers. 11 and C 12 Aromatics are further processed in an aromatics complex to produce benzene, toluene, and xylene (BTX). Alternatively, they are used as a precursor in a naphtha reformer to form C. 11 and C 12 C, the precursor of aromatic hydrocarbons 11 and C 12 When molecules are allowed to enter the reformer and the aromatics complex, they are discharged from the bottom stream of the heavy aromatics tower and do not contribute to BTX production.
[0004] This leads to the loss of compounds that can be converted into BTX products.
[0005] Therefore, a method is needed that would allow the use of C in aromatic complexes. 11 and C 12 Aromatics, thereby increasing the yield of BTX products. Attached Figure Description
[0006] Figure 1 This is a diagram of a prior art aromatics complex that does not have a heavy aromatics unit.
[0007] Figure 2 It is one implementation scheme of a combined unit with heavy aromatic hydrocarbon units. Detailed Implementation
[0008] This method upgrades the low-value heavy aromatics stream, which would otherwise be discharged from the bottom of the heavy aromatics tower, into a high-value BTX precursor stream. It processes C9 to C6 precursors before reaching the downstream alkyl transfer reactor.12 Naphthalene molecules, such as naphthalene and alkylnaphthalenes, in heavy aromatic streams are converted into BTX precursors by partially hydrogenating one aromatic ring and subsequently opening the saturated ring to form a monoaromatic hydrocarbon. With a significantly reduced naphthalene content, the remaining C... 11 and C 12 Monoaromatic hydrocarbons can be processed in alkyl transfer reactors to achieve an overall increase in BTX production.
[0009] This method offers relatively low capital and operating costs and improves molecular management of aromatics used in BTX production. It provides opportunities to reduce carbon intensity and increase net hydrogen, as well as increase BTX yield per tonne of feed.
[0010] This method can be adapted from existing aromatics complexes and designed into new aromatics complexes. It involves adding a reactor containing a hydrogenation-functional catalyst (such as cobalt and molybdenum on an alumina support) to hydrogenate a ring of a naphthalene compound, thereby forming tetrahydronaphthalene and substituted tetrahydronaphthalene. The reactor system may also contain a second catalyst bed containing a cracking-functional catalyst (such as molybdenum on an MFI-type zeolite and alumina support) to ring-open the tetrahydronaphthalene, and then dealkylate the tetrahydronaphthalene to form a monocyclic aromatic compound. Alternatively, ring-opening / dealkylation can be carried out in a separate reactor or in a downstream alkyl transfer reactor.
[0011] If the heavy aromatics feed stream also includes indane and / or alkyl indane, the catalyst with cracking function can also open the rings of indane and alkyl indane and dealkylate the ring-opened indane and alkyl indane.
[0012] The heavy aromatics conversion process is carried out in an aromatics complex and involves the conversion of bicyclic aromatic compounds. The heavy aromatics feed stream into the heavy aromatics conversion process has an aromatics content of 95% or more and contains C9 to C6 compounds containing naphthalene and alkylnaphthalene. 12 Aromatic hydrocarbons. Naphthalene and alkylnaphthalene in a heavy aromatic hydrocarbon stream are hydrogenated under hydrogenation conditions in the presence of a catalyst with hydrogenation function to form a partially hydrogenated reaction mixture containing tetrahydronaphthalene and alkyltetrahydronaphthalene.
[0013] In the presence of a catalyst with ring-opening and dealkylation functions, under ring-opening and dealkylation reaction conditions, the partially hydrogenated reaction mixture can be further processed to allow tetrahydronaphthalene and alkyltetrahydronaphthalene to undergo ring-opening to form alkyl monoaromatics, and the alkyl monoaromatics to undergo dealkylation to form dealkylated monoaromatics.
[0014] Naphthalene and alkylnaphthalene can be hydrogenated in a first reactor, and the partially hydrogenated reaction mixture can be treated in a second reactor. Alternatively, the hydrogenation of naphthalene and alkylnaphthalene, as well as the treatment of the partially hydrogenated reaction mixture, can be carried out in a single reactor.
[0015] The method may also include alkyl transfer of a dealkylated monoaromatic hydrocarbon to form an alkyl-transferred product in the presence of an aromatic alkyl transfer catalyst and under aromatic alkyl transfer reaction conditions.
[0016] In some embodiments, the hydrogenation of naphthalene and alkylnaphthalene, as well as the treatment of the partially hydrogenated reaction mixture, are carried out in different beds within a single reactor.
[0017] In some embodiments, the hydrogenation of naphthalene and alkylnaphthalene, as well as the treatment of the partially hydrogenated reaction mixture, are carried out in different beds in a first reactor, and the alkyl transfer of the dealkylated monoaromatic hydrocarbon is carried out in a second reactor.
[0018] In some embodiments, hydrogenation of naphthalene and alkylnaphthalene is carried out in a first reactor, and treatment of the partially hydrogenated reaction mixture and alkyl transfer of the dealkylated monoaromatic hydrocarbon are carried out in different beds in a second reactor.
[0019] In some embodiments, hydrogenation of naphthalene and alkylnaphthalene is carried out in a first reactor, treatment of the partially hydrogenated reaction mixture is carried out in a second reactor, and alkyl transfer of the dealkylated monoaromatic hydrocarbon is carried out in a third reactor.
[0020] In some embodiments, the hydrogenation of naphthalene and alkylnaphthalene, the treatment of the partially hydrogenated reaction mixture, and the alkyl transfer of the dealkylated monoaromatic hydrocarbon are carried out in different beds within a single reactor.
[0021] In some embodiments, hydrogenation of naphthalene and alkylnaphthalene is carried out in a first reactor, and treatment of the partially hydrogenated reaction mixture and alkyl transfer of the dealkylated monoaromatic hydrocarbon are carried out in a second reactor, wherein the aromatic alkyl transfer catalyst has ring-opening and dealkylation functions.
[0022] In some embodiments, hydrogenation of naphthalene and alkylnaphthalene is carried out in a first bed of the reactor, and treatment of the partially hydrogenated reaction mixture and alkyl transfer of the dealkylated monoaromatic hydrocarbon are carried out in a second bed of the reactor, wherein the aromatic alkyl transfer catalyst has ring-opening and dealkylation functions.
[0023] In some embodiments, the heavy aromatic stream further comprises indane and alkyl indane, and the treatment of the partially hydrogenated reaction mixture includes ring-opening the indane and alkyl indane to form additional monoaromatics, and dealkylating the additional alkyl monoaromatics to form additional dealkylated monoaromatics.
[0024] In some implementations, the heavy aromatics feed stream further comprises C6 to C8 aromatics and C6 to C8 aromatics. 13 To C 14 Aromatics. In some embodiments, C6-C8 aromatics may be added downstream of the heavy aromatics conversion process.
[0025] In some embodiments, the hydrogenation-functional catalyst comprises metals from Groups 6 to 10 of the periodic table. In some embodiments, the hydrogenation-functional catalyst comprises Mo, Ni, Co, or combinations thereof.
[0026] In some embodiments, the catalyst having ring-opening and dealkylation functions comprises metals and zeolites from Groups 6 to 10, including MFI-type zeolites or MOR-type zeolites or combinations thereof.
[0027] In some implementations, the catalyst with ring-opening and dealkylation functions comprises Mo, Pt, or Re, or combinations thereof.
[0028] In some embodiments, hydrogenation conditions include temperatures in the range of 200°C to 450°C, or pressures in the range of 1 MPa to 5 MPa, or combinations thereof.
[0029] In some embodiments, the ring-opening and dealkylation conditions include temperatures in the range of 200°C to 450°C, or pressures in the range of 1 MPa to 5 MPa, or combinations thereof.
[0030] In some embodiments, the aromatic alkyl transfer conditions include a temperature in the range of 200°C to 450°C, or a pressure in the range of 1 MPa to 5 MPa, or a combination thereof.
[0031] Heavy aromatics feedstocks are typically derived from naphtha reformers or various other sources, such as petroleum refining, thermal or catalytic cracking, or petrochemical conversion with appropriate aromatic content. Processing aromatics feedstocks within the aromatics complex 100 to produce para-xylene, according to known techniques, is typically as follows: Figure 1 The process is as shown. The aromatics complex 100 includes a xylene fractionation section 200, an adsorption separation section 300, an isomerization section 400, a benzene / toluene separation section 500, and an alkyl transfer reaction section 600.
[0032] For example, but not limiting the invention, the feed stream 201 will contain non-aromatic hydrocarbons, benzene, toluene, C8 alkyl monoaromatic isomers and their C5-C6 derivatives.11 The mixture comprises a mixture of heavier hydrocarbons, including heavy aromatics such as C9 and heavier alkyl monoaromatics, naphthalene, and alkylnaphthalenes. This invention is demonstrated by the performance of a feed stream containing, for example, a substantial amount, such as about 1% by weight or more, or at least 5% by weight, of C9 and heavier hydrocarbons.
[0033] The xylene fractionation section 200 includes a reforming product separation tower fractionator 202, an aromatics stripping tower fractionator 206, an aromatics re-distillation fractionator 210, and a heavy aromatics fractionator 214.
[0034] The feed stream from 201 is separated in the reforming product separator fractionator 202 into a reforming product separator top stream 203, which mainly contains C5-C7 non-aromatic hydrocarbons, benzene and toluene; a reforming product separator side stream 204, which mainly contains benzene and toluene; and a reforming product separator bottom stream 205, which mainly contains C8 and heavier aromatic hydrocarbons.
[0035] The reformate separation column bottom stream 205, the C8 alkyl aromatics recycle stream 504 mainly containing benzene and toluene from the benzene / toluene separation section 500, and the isomerization effluent stream 401 from the isomerization section 400 are combined and separated in the aromatics stripper fractionator 206 into an aromatics stripper overhead stream 207 mainly containing benzene and toluene, an aromatics stripper side stream 208 mainly containing C8 alkyl aromatics, and an aromatics stripper bottom stream 209 mainly containing a concentrated mixture of C8 and heavier alkyl monoaromatics, naphthalene, and alkylnaphthalene.
[0036] The aromatic stripper bottom stream 209 from the aromatic stripper fractionator 206 is separated in the aromatic "redistillation" fractionator 210 into an aromatic redistillation top stream 211 mainly containing C8 alkyl monoaromatics, an aromatic redistillation side stream 212 mainly containing C9 alkyl monoaromatics, and an aromatic redistillation side stream 212 mainly containing C9 alkyl monoaromatics. 10 And heavier alkyl monoaromatics and concentrated naphthalene and alkyl naphthalene aromatics re-distillation tower bottom stream 213.
[0037] The bottom stream 213 of the aromatics rediscount tower is separated into compounds containing C9 to C6 in the "heavy aromatics" fractionator 214. 11 The heavy aromatics overhead feed stream 215, which may contain naphthalene and alkylnaphthalenes, and mainly contains C 11 And heavier aromatic hydrocarbons in the bottom feed stream 216. Figure 1In the aromatics complex, the amount of naphthalene and alkylnaphthalene in the heavy aromatics tower overhead stream 215 must be limited so that the combined feed to the inlet section 600 is, for example, less than 0.5% by weight or at most 2.0% by weight of naphthalene and alkylnaphthalene, to prevent these components from adversely affecting the downstream alkyl transfer reaction section 600, isomerization section 400, adsorption separation section 300, and benzene / toluene separation section 500. These components discharged to the heavy aromatics tower bottom stream 216 represent potential losses of BTX precursors.
[0038] The top stream 203 of the reforming product separation tower is sent to the benzene / toluene section 500, thereby forming a benzene stream 501, a raffinate stream 502, a toluene stream 503, and a C8 alkyl aromatics stream 504. The C8 alkyl aromatics stream 504 is sent as a recycle to the aromatics stripping tower fractionator 206.
[0039] The reformate separation tower side stream 204, the aromatic stripping tower top stream 207, the aromatic redistillation side stream 212, and the toluene stream 503 are combined and sent to the alkyl transfer section 600. The alkyl transfer effluent stream 601 is recycled to the benzene / toluene section 500.
[0040] The aromatic stripping column side stream 208 and the aromatic redistillation column overhead stream 211 are combined into a mixture of xylene isomers. The adsorption separation section 300 includes a para-xylene selective embodiment to form a para-xylene-rich stream 301 and a mixed xylene stream 302. In other embodiments, the desired xylene isomer may also be m-xylene or o-xylene.
[0041] The mixed xylene stream 302 is sent to the isomerization section 400. The isomerization effluent stream 401 is recycled to the aromatic stripping column fractionator 206.
[0042] Figure 2 An embodiment of the method according to the invention is illustrated. This embodiment utilizes... Figure 1 The aromatics complex 100 depicted includes a heavy aromatics processing unit 217 added within the xylene fractionation section 200. Figure 2 In the embodiment shown, the heavy aromatics top feed stream 215 is conveyed through the heavy aromatics conversion unit 217, instead of as... Figure 1 The feed shown is conveyed to the alkyl transfer section 600. Figure 2 In this process, the overhead feed stream 215 containing naphthalene and alkylnaphthalene is directed to the heavy aromatics unit 217, where partial hydrogenation to tetrahydronaphthalene and substituted tetrahydronaphthalene occurs, and in some cases, ring-opening and dealkylation reactions take place. Therefore, the amount of naphthalene and alkylnaphthalene in the overhead feed stream 215 does not need to be as... Figure 1The method is not as restrictive as in the past, and these naphthalene and alkylnaphthalene components help increase the BTX production of the aromatics complex, rather than being discharged from the aromatics complex into the heavy aromatics bottom stream 216. The heavy aromatics unit effluent stream 218 from the heavy aromatics unit 217 is combined with the reformate separation tower side stream 204, the aromatics stripping tower top stream 207, the aromatics redistillation side stream 212, and the toluene stream 503, and sent to the alkyl transfer section 600.
[0043] The exemplary flowchart illustrates one example of an aromatics complex 100 known in the art. It should be understood that many other examples of aromatics complexes exist, and the exemplary embodiment is not intended to limit the scope, application, or configuration of this application in any way. For example, [the following is a list of possible embodiments:] from […]. Figure 2 Additional feed stream introduced from outside the aromatics complex Figure 2 The aromatics complex aims to increase overall BTX production through the heavy aromatics conversion unit 217.
[0044] Given that the function and arrangement of the elements described in the exemplary embodiments can be changed without departing from the scope described in the specific claims, the embodiments represent an overview of how a person skilled in the art implements the method.
[0045] Example
[0046] Example 1
[0047] A hydrogenation catalyst containing alumina, cobalt, and molybdenum was prepared by extrusion molding for pilot plant testing.
[0048] The catalyst was tested in a single-bed reactor to evaluate the conversion of naphthalene and methylnaphthalene to tetrahydronaphthalene and alkyltetrahydronaphthalene under 220-300 °C, 400 psig, 1H2 / HC, 3WHSV and 100% aromatics content feed as described in Table 1.
[0049] Table 1
[0050]
[0051] As shown in Table 2, naphthalene and methylnaphthalene are hydrogenated to form tetrahydronaphthalene and methyltetrahydronaphthalene, which have minimal monoaromatic ring loss under given conditions and temperature ranges.
[0052] Table 2
[0053]
[0054] Example 2
[0055] Catalysts containing Mo, MFI zeolite, and MOR zeolite with ring-opening and dealkylation functions were prepared by extrusion molding for pilot plant testing.
[0056] The catalyst was tested in a single-bed reactor to evaluate the conversion of tetrahydronaphthalene and indane at 400 psig, 3H2 / HC, 3WHSV and 100% aromatics content feed as described in Table 3.
[0057] Table 3
[0058]
[0059] As shown in Table 3, tetrahydronaphthalene and indane are converted under given conditions and temperature ranges.
[0060] Table 4
[0061]
[0062] Specific implementation plan
[0063] While the following description is presented in conjunction with specific embodiments, it should be understood that the description is intended to be illustrative and not to limit the scope of the foregoing description and the appended claims.
[0064] A first embodiment of the present invention is a method for converting bicyclic aromatic compounds in an aromatics complex, the method comprising providing a heavy aromatics feed having an aromatics content of 95% or more and comprising C9 to C11 aromatics, the C9 to C11 aromatics comprising naphthalene and alkylnaphthalene; and hydrogenating the naphthalene and the alkylnaphthalene under hydrogenation conditions in the presence of a catalyst with hydrogenation function to form a partially hydrogenated reaction mixture comprising tetrahydronaphthalene and alkyltetrahydronaphthalene. An embodiment of the present invention is any one or all of the preceding embodiments to the first embodiment of this paragraph, further comprising treating the partially hydrogenated reaction mixture under ring-opening and dealkylation reaction conditions in the presence of a catalyst with ring-opening and dealkylation function, thereby causing the tetrahydronaphthalene and alkyltetrahydronaphthalene to ring-open to form alkyl monoaromatics, and dealkylating the alkyl monoaromatics to form dealkylated monoaromatics. One embodiment of the invention is any one, any one, or all of the preceding embodiments to the first embodiment of this paragraph, further comprising, in the presence of an aromatic alkyl transfer catalyst, performing alkyl transfer on the dealkylated monoaromatic hydrocarbon under aromatic alkyl transfer reaction conditions to form an alkyl-transferred product. One embodiment of the invention is any one, any one, or all of the preceding embodiments to the first embodiment of this paragraph, wherein the hydrogenation of the naphthalene and the alkylnaphthalene, and the treatment of the partially hydrogenated reaction mixture, are carried out in different beds within a single reactor. One embodiment of the invention is any one, any one, or all of the preceding embodiments to the first embodiment of this paragraph, wherein the hydrogenation of the naphthalene and the alkylnaphthalene, and the treatment of the partially hydrogenated reaction mixture, are carried out in different beds within a first reactor, and wherein the alkyl transfer of the dealkylated monoaromatic hydrocarbon is carried out in a second reactor. One embodiment of the invention is any one or all of the preceding embodiments to the first embodiment of this paragraph, wherein the hydrogenation of the naphthalene and the alkylnaphthalene is carried out in a first reactor, and wherein the treatment of the partially hydrogenated reaction mixture and the alkyl transfer of the dealkylated monoaromatic hydrocarbon are carried out in different beds in a second reactor. Another embodiment of the invention is any one or all of the preceding embodiments to the first embodiment of this paragraph, wherein the hydrogenation of the naphthalene and the alkylnaphthalene is carried out in a first reactor, wherein the treatment of the partially hydrogenated reaction mixture is carried out in a second reactor, and wherein the alkyl transfer of the dealkylated monoaromatic hydrocarbon is carried out in a third reactor.One embodiment of the invention is any one or all of the preceding embodiments to the first embodiment of this paragraph, wherein the hydrogenation of the naphthalene and the alkylnaphthalene, the treatment of the partially hydrogenated reaction mixture, and the alkyl transfer of the dealkylated monoaromatic hydrocarbon are carried out in different beds within a single reactor. Another embodiment of the invention is any one or all of the preceding embodiments to the first embodiment of this paragraph, wherein the hydrogenation of the naphthalene and the alkylnaphthalene is carried out in a first reactor, and wherein the treatment of the partially hydrogenated reaction mixture and the alkyl transfer of the dealkylated monoaromatic hydrocarbon are carried out in a second reactor, wherein the aromatic alkyl transfer catalyst has the ring-opening and dealkylation functions. Another embodiment of the invention is any one or all of the preceding embodiments to the first embodiment of this paragraph, wherein the hydrogenation of the naphthalene and the alkylnaphthalene is carried out in a first bed within a reactor, and wherein the treatment of the partially hydrogenated reaction mixture and the alkyl transfer of the dealkylated monoaromatic hydrocarbon are carried out in a second bed within a reactor, wherein the aromatic alkyl transfer catalyst has the ring-opening and dealkylation functions. One embodiment of the invention is any one, any one, or all of the previous embodiments to the first embodiment of this paragraph, wherein the heavy aromatic hydrocarbon feed further comprises indane and alkyl indane, and wherein treating the partially hydrogenated reaction mixture comprises ring-opening the indane and alkyl indane to form additional monoaromatic hydrocarbons, and dealkylating the additional alkyl monoaromatic hydrocarbons to form additional dealkylated monoaromatic hydrocarbons. One embodiment of the invention is any one, any one, or all of the previous embodiments to the first embodiment of this paragraph, wherein the heavy aromatic hydrocarbon feed further comprises C6 to C8 aromatic hydrocarbons and C12 to C13 aromatic hydrocarbons. One embodiment of the invention is any one, any one, or all of the previous embodiments to the first embodiment of this paragraph, wherein the catalyst having the hydrogenation function comprises metals from Groups 6 to 10 of the periodic table. One embodiment of the invention is any one, any one, or all of the previous embodiments to the first embodiment of this paragraph, wherein the catalyst having the hydrogenation function comprises Mo, Ni, Co, or combinations thereof. One embodiment of the present invention is any one, any one, or all of the preceding embodiments to the first embodiment of this paragraph, wherein the catalyst having the ring-opening and dealkylation function comprises metals and zeolites from Groups 6 to 10, wherein the zeolites include MFI-type zeolites or MOR-type zeolites or combinations thereof. Another embodiment of the present invention is any one, any one, or all of the preceding embodiments to the first embodiment of this paragraph, wherein the catalyst having the ring-opening and dealkylation function comprises Mo, Pt, or Re or combinations thereof.One embodiment of the invention is any one, any one, or all of the preceding embodiments to the first embodiment of this paragraph, wherein the hydrogenation conditions include a temperature in the range of 200°C to 450°C, or a pressure in the range of 1 MPa to 5 MPa, or a combination thereof. One embodiment of the invention is any one, any one, or all of the preceding embodiments to the first embodiment of this paragraph, wherein the ring-opening and dealkylation conditions include a temperature in the range of 200°C to 450°C, or a pressure in the range of 1 MPa to 5 MPa, or a combination thereof. One embodiment of the invention is any one, any one, or all of the preceding embodiments to the first embodiment of this paragraph, wherein the aromatic alkyl transfer conditions include a temperature in the range of 200°C to 450°C, or a pressure in the range of 1 MPa to 5 MPa, or a combination thereof. One embodiment of the invention is any one, any one, or all of the preceding embodiments to the first embodiment of this paragraph, wherein the hydrogenation of the naphthalene and the alkylnaphthalene, and the treatment of the partially hydrogenated reaction mixture, are carried out in a separate reactor.
[0065] Although no further detailed description has been provided, it is believed that those skilled in the art will be able to make full use of the invention by employing the foregoing description and will be able to readily identify the essential features of the invention without departing from its spirit and scope, and to make various changes and modifications to adapt it to various uses and situations. Therefore, the foregoing preferred embodiments should be understood as illustrative only and not as limiting the remainder of this disclosure in any way, and are intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.
[0066] In the foregoing, all temperatures are expressed in degrees Celsius, and all portions and percentages are by weight unless otherwise specified.
Claims
1. A method for converting heavy aromatics into bicyclic aromatic compounds in an aromatics complex, the method comprising: Provides aromatics with 95% or more content and containing C9 to C14. 11 Heavy aromatics feed stream (215), C9 to C 11 Aromatic hydrocarbons include naphthalene and alkylnaphthalene; as well as In the presence of a catalyst with hydrogenation function, the naphthalene and the alkylnaphthalene are hydrogenated under hydrogenation conditions to form a partially hydrogenated reaction mixture comprising tetrahydronaphthalene and alkyltetrahydronaphthalene.
2. The method according to claim 1, further comprising: In the presence of a catalyst with ring-opening and dealkylation functions, the partially hydrogenated reaction mixture is treated under ring-opening and dealkylation reaction conditions, thereby causing the tetrahydronaphthalene and alkyltetrahydronaphthalene to undergo ring-opening to form alkyl monoaromatics, and causing the alkyl monoaromatics to undergo dealkylation to form dealkylated monoaromatics.
3. The method according to claim 2, further comprising: In the presence of an aromatic alkyl transfer catalyst, under aromatic alkyl transfer reaction conditions, the dealkylated monoaromatic hydrocarbon undergoes alkyl transfer to form an alkyl-transferred product.
4. The method of claim 2, wherein the hydrogenation of the naphthalene and the alkylnaphthalene, and the treatment of the partially hydrogenated reaction mixture, are carried out in different beds within a single reactor.
5. The method of claim 3, wherein the hydrogenation of the naphthalene and the alkylnaphthalene and the treatment of the partially hydrogenated reaction mixture are carried out in different beds in a first reactor, and wherein the alkyl transfer of the dealkylated monoaromatic hydrocarbon is carried out in a second reactor.
6. The method of claim 3, wherein the hydrogenation of the naphthalene and the alkylnaphthalene is carried out in a first reactor, and wherein the treatment of the partially hydrogenated reaction mixture and the alkyl transfer of the dealkylated monoaromatic hydrocarbon are carried out in different beds in a second reactor.
7. The method of claim 3, wherein hydrogenation of the naphthalene and the alkylnaphthalene is carried out in a first reactor, wherein treatment of the partially hydrogenated reaction mixture is carried out in a second reactor, and wherein alkyl transfer of the dealkylated monoaromatic hydrocarbon is carried out in a third reactor.
8. The method of claim 3, wherein the hydrogenation of the naphthalene and the alkylnaphthalene, the treatment of the partially hydrogenated reaction mixture, and the alkyl transfer of the dealkylated monoaromatic hydrocarbon are carried out in different beds in a single reactor.
9. The method of claim 3, wherein hydrogenation of the naphthalene and the alkylnaphthalene is carried out in a first reactor, and wherein treatment of the partially hydrogenated reaction mixture and alkyl transfer of the dealkylated monoaromatic hydrocarbon are carried out in a second reactor, and wherein the aromatic alkyl transfer catalyst has the ring-opening and dealkylation functions.
10. The method of claim 3, wherein the hydrogenation of the naphthalene and the alkylnaphthalene is carried out in a first bed of a reactor, and wherein the treatment of the partially hydrogenated reaction mixture and the alkyl transfer of the dealkylated monoaromatic hydrocarbon are carried out in a second bed of the reactor, and wherein the aromatic alkyl transfer catalyst has the ring-opening and dealkylation functions.