Production of aromatics by conversion of syngas to methanol and aromatization

Abstract

Disclosed is a process for converting a hydrocarbon feedstock, in which a first hydrocarbon feedstock (2) is treated in particular by means of a fractionation train (4-7), a xylene separation unit (10) and an isomerization unit (11), and in which: a pyrolysis unit (13) or an oxycombustion or gasification unit (14) treats a second hydrocarbon feedstock (30) to produce a syngas (32) comprising CO and CO2; a methanol synthesis reaction section (50) treats the syngas to produce methanol (51); and an aromatization reaction section (56) at least partially treats the methanol to produce a hydrocarbon effluent (57) comprising aromatic compounds, and to feed the hydrocarbon feedstock with the hydrocarbon effluent.

Description

[0001] Production of aromatics by conversion of synthesis gas to methanol and aromatization

[0002] Technical field

[0003] The invention relates to the production of aromatics for petrochemistry (benzene, toluene, xylenes, ie, BTX). More particularly, the subject of the invention relates to the production of aromatics (eg paraxylene) from the conversion of hydrocarbon compounds (eg biomass) into synthesis gas comprising CO and CO2.

[0004] An aromatic complex (or aromatics conversion device) is a device powered by feedstocks predominantly composed of six to ten or more carbon atoms, referred to as C6 to C10+ feedstocks. Different sources of aromatics can be introduced into an aromatic complex, the most common being derived from a catalytic naphtha reforming process.

[0005] Within an aromatic complex, regardless of the source of aromatics, benzene and aromatic alkyls (e.g. toluene, paraxylene, orthoxylene) are extracted and then converted into desired intermediates. The products of interest are aromatics with 0 (benzene), 1 (toluene) or 2 (xylenes) methyl groups, and in particular, within xylenes, paraxylene, having the highest market value.

[0006] Oxy-fuel pyrolysis and hydrocarbon gasification processes produce a large amount of recoverable carbon monoxide (CO) and carbon dioxide (CO2). Pyrolysis processes also produce aromatic compounds. When pyrolysis is catalytic, the combustion of coke present on the catalyst used in the pyrolysis reactor also produces a significant amount of CO2.

[0007] Prior art

[0008] To date, aromatic complexes can be used to produce benzene, possibly toluene, and xylenes (often paraxylene, sometimes orthoxylene). An aromatic complex generally has at least one catalytic unit with at least one of the following functions: the isomerization of aromatic compounds with 8 carbon atoms, denoted A8 compounds, to convert orthoxylene, metaxylene and ethylbenzene into paraxylene; transalkylation to produce xylenes from a mixture of toluene (and optionally benzene) and A9+ compounds such as trimethylbenzenes and tetramethylbenzenes; and the disproportionation of toluene, which can produce benzene and xylenes. The aromatic loop can produce high-purity paraxylene by adsorption separation or by crystallization, an operation well known in the prior art. This “C8-aromatic loop” includes a step of elimination of heavy compounds (i.e., C9+) in a distillation column called the “xylene column”. The overhead stream from this column, which contains the C8-aromatic isomers (i.e., A8), is then sent to the paraxylene separation process, which is most commonly a simulated moving bed adsorption separation (SMB) process to produce an extract and a raffinate, or a crystallization process in which a paraxylene fraction is isolated from the rest of the mixture constituents in the form of crystals.

[0009] The extract, which contains paraxylene, is then distilled to obtain high-purity paraxylene. The raffinate, rich in metaxylene, orthoxylene and ethylbenzene, is treated in a catalytic isomerization unit which gives back a mixture of C8 aromatics, in which the proportion of xylenes (ortho-, meta-, para-xylenes) is practically at thermodynamic equilibrium and the quantity of ethylbenzene is reduced. This mixture is again sent to the "xylene column" with the fresh feed.

[0010] Aromatic complexes producing benzene and paraxylene are overwhelmingly supplied by feedstocks derived from oil or natural gas. These complexes do not allow the production of bio-sourced aromatics. Another challenge is to recover carbon in the form of CO and CO2, and in particular bio-sourced carbon, into high value-added compounds. One object of the present invention is to overcome these drawbacks.

[0011] Summary of the invention

[0012] In the context described above, a first object of the present description is to overcome the problems of the prior art and to provide a method and a device for producing aromatics for petrochemistry making it possible to convert (for example all) of the CO and CO2 produced by pyrolysis, oxycombustion or gasification, into additional aromatic compounds. The CO2 from the combustion of the coke present on the catalyst of the pyrolysis process can also be advantageously converted into aromatic compounds.

[0013] The invention is based on the conversion of carbon monoxide, i.e., CO, and carbon dioxide, i.e., CO2, into aromatic compounds which are introduced into the aromatic complex, and in particular on the arrangement of several units making it possible to convert CO and CO2 into aromatic compounds in two stages: in a methanol synthesis reactor and then in a methanol aromatization reactor. The aromatic compounds resulting from the conversion of CO2 are treated within the aromatic loop.

[0014] Specifically, the subject matter of the present invention relates to a method and a device using and comprising a unit for converting the mixture of CO and CO2 into methanol followed by a unit for aromatizing the methanol, respectively. Advantageously, the aromatic compounds resulting from the aromatization of methanol are introduced into the aromatic complex to be transformed into benzene and paraxylene.

[0015] According to a first aspect, the aforementioned objects, as well as other advantages, are obtained by a method for converting a first hydrocarbon feedstock comprising aromatic compounds, comprising the following steps: fractionating the first hydrocarbon feedstock in a fractionation train to extract at least one cut comprising benzene, one cut comprising toluene and one cut comprising xylenes and ethylbenzene; separating the cut comprising xylenes and ethylbenzene in a xylene separation unit and producing an extract comprising paraxylene and a raffinate comprising orthoxylene, metaxylene and ethylbenzene; isomerizing the raffinate in an isomerization unit and producing an isomerate enriched in paraxylene;

[0016] - sending the paraxylene-enriched isomerate to the fractionation train; treating a second hydrocarbon feedstock in a synthesis gas production unit, such as for example a pyrolysis, oxycombustion or gasification unit, to produce a synthesis gas comprising at least carbon monoxide (CO) and carbon dioxide (CO2); treating the synthesis gas in a methanol synthesis reaction section to produce methanol; treating at least in part the methanol in an aromatization reaction section to produce a hydrocarbon effluent comprising aromatic compounds; and feeding the first hydrocarbon feedstock at least in part with the hydrocarbon effluent.

[0017] One of the advantages of the present invention is in particular to be able to convert methanol into aromatic compounds in a single step from synthesis gas.

[0018] According to one or more embodiments, the method comprises treating methanol in a purification section to separate water and produce purified methanol.

[0019] According to one or more embodiments, the purification section is adapted to separate a recycle gas comprising unconverted CO and / or unconverted CO2, and recycle the recycle gas to the inlet of the methanol synthesis reaction section.

[0020] One of the advantages of the present invention is in particular to be able, by means of recycling, to convert all of the synthesis gas. According to one or more embodiments, the synthesis gas production unit comprises a pyrolysis unit adapted to produce at least one pyrolysis effluent comprising hydrocarbon compounds of 6 to 10 carbon atoms at least partially feeding the first hydrocarbon feedstock.

[0021] According to one or more embodiments, the method comprises providing a supply of hydrogen (H2) in the synthesis gas by means of a make-up line, for example arranged (directly) upstream of the methanol synthesis reaction section.

[0022] According to one or more embodiments, the method comprises treating the hydrocarbon effluent in a separation section to separate water and a light gas purge comprising hydrogen and C1-C2 hydrocarbon compounds, and producing an effluent enriched in aromatic compounds to feed the first hydrocarbon feedstock.

[0023] According to one or more embodiments, the separation section is adapted to: separate a recycle effluent comprising at least one of the following compounds: C3-C4 hydrocarbon compounds, C5-C10 non-aromatic hydrocarbon compounds, benzene, toluene; and recycle the recycle effluent to the inlet of the aromatization reaction section.

[0024] One of the advantages of the present invention is in particular to be able, by means of recycling, to convert non-aromatic hydrocarbon compounds into aromatics. One of the advantages of the present invention is in particular to be able, by means of recycling, to alkylate benzene and toluene into xylenes.

[0025] According to one or more embodiments, the synthesis gas production unit comprises: a pyrolysis unit comprising at least one reactor used under at least one of the following operating conditions: absolute pressure between 0.1 MPa and 0.5 MPa and WH between 0.01 h -1 and 10 a.m. 1 , preferably between 0.01 h -1 and 5 a.m. -1 , and very preferably between 0.1 h -1 and 3 hours -1, WH is the ratio of the volume flow rate of feedstock to the volume of catalyst used; temperature between 400°C and 1000°C, preferably between 400°C and 650°C, preferably between 450°C and 600°C and preferably between 450°C and 590°C; zeolitic catalyst comprising and preferably consisting of at least one zeolite chosen from ZSM-5, ferrierite, zeolite Beta, zeolite Y, mordenite, ZSM-23, ZSM-57, EU-1, ZSM-11 and preferably the catalyst is a catalyst comprising only ZSM-5; or an oxycombustion unit comprising at least one reactor used in at least one of the following operating conditions: a reactor operating in a fluidized bed; temperature between 500°C and 1000°C; pressure between 0.1 MPa and 3 MPa, preferably between 0.1 MPa and 1 MPa; or a gasification unit comprising at least one gasification furnace used under at least one of the following operating conditions: temperature between 700°C and 1400°C.

[0026] According to one or more embodiments, the methanol synthesis reaction section comprises at least one reactor used under at least one of the following operating conditions: temperature between 200°C and 450°C, preferably between 220°C and 400°C, and more preferably still between 250°C and 350°C; pressure between 1 MPa and 12 MPa, preferably between 2 MPa and 10 MPa, and more preferably between 5 MPa and 10 MPa; molar ratio of hydrogen to COx in which COx represents CO and CO2, between 3 and 10, preferably between 3 and 7, very preferably between 3 and 5; space velocity of the gas at the reactor inlet between 0.2 g / g ca ta / h and 1 g / g ca your / h.

[0027] According to one or more embodiments, the aromatization reaction section comprises at least one reactor used under at least one of the following operating conditions: temperature between 250°C and 500°C, preferably between 300°C and 450°C, and more preferably still between 350°C and 420°C; pressure between 0.1 MPa and 1 MPa, preferably between 0.2 MPa and 0.8 MPa, and more preferably between 0.4 MPa and 0.5 MPa; space velocity of the gas at the reactor inlet between 0.2 g / g ca ta / h and 1 g / g ca your / h.

[0028] According to a second aspect, the aforementioned objects, as well as other advantages, are obtained by a device for converting a first hydrocarbon feedstock comprising aromatic compounds, comprising: a fractionation train adapted to extract at least one cut comprising benzene, a cut comprising toluene and a cut comprising xylenes and ethylbenzene from the first hydrocarbon feedstock; a xylene separation unit adapted to treat the cut comprising xylenes and ethylbenzene and produce an extract comprising paraxylene and a raffinate comprising orthoxylene, metaxylene and ethylbenzene; an isomerization unit adapted to treat the raffinate and produce an isomerate enriched in paraxylene sent to the fractionation train;a synthesis gas production unit, such as for example a pyrolysis unit or an oxycombustion or gasification unit, adapted to treat a second hydrocarbon feedstock and produce a synthesis gas comprising at least carbon monoxide (CO) and carbon dioxide (CO2); a methanol synthesis reaction section adapted to convert CO and CO2 of the synthesis gas into methanol; and an aromatization reaction section adapted to convert at least in part the methanol into aromatic compounds and produce a hydrocarbon effluent comprising aromatic compounds, and feed the first hydrocarbon feedstock at least in part with the hydrocarbon effluent.;

[0029] According to one or more embodiments, the device comprises a purification section adapted to process the methanol to separate it from water and produce purified methanol.

[0030] According to one or more embodiments, the purification section is adapted to separate a recycle gas comprising unconverted CO and / or unconverted CO2, and recycle the recycle gas to the inlet of the methanol synthesis reaction section.

[0031] According to one or more embodiments, the synthesis gas production unit comprises a pyrolysis unit adapted to produce at least one pyrolysis effluent comprising hydrocarbon compounds of 6 to 10 carbon atoms at least partially feeding the first hydrocarbon feedstock.

[0032] According to one or more embodiments, the device comprises a make-up line for providing a supply of hydrogen in the synthesis gas.

[0033] According to one or more embodiments, the device comprises a separation section adapted to treat the hydrocarbon effluent to separate water and a light gas purge comprising hydrogen and C1-C2 hydrocarbon compounds, and to produce an effluent enriched in aromatic compounds to feed the first hydrocarbon feedstock.

[0034] According to one or more embodiments, the separation section is adapted to: separate a recycle effluent comprising at least one of the following compounds: C3-C4 hydrocarbon compounds, C5-C10 non-aromatic hydrocarbon compounds, benzene, toluene; and recycle the recycle effluent to the inlet of the aromatization reaction section.

[0035] Embodiments according to the first aspect and the second aspect, as well as other characteristics and advantages of the devices and methods according to the aforementioned aspects, will appear on reading the following description, given for illustrative and non-limiting purposes only, and with reference to the following drawing.

[0036] List of figures

[0037] Figure 1 represents a schematic view of a method according to the present invention for increasing the production of aromatic compounds.

[0038] Description of the embodiments

[0039] Embodiments of the method according to the first aspect and the device according to the second aspect will now be described in detail. In the following detailed description, numerous specific details are set forth in order to provide a more thorough understanding of the method. However, it will be apparent to those skilled in the art that the method can be carried out without these specific details. In other cases, well-known features have not been described in detail to avoid unnecessarily complicating the description.

[0040] In the present application, the term "comprise" is synonymous with (means the same as) "include" and "contain", and is inclusive or open and does not exclude other elements not recited. It is understood that the term "comprise" includes the exclusive and closed term "consist". Furthermore, in the present description, an effluent comprising essentially or solely compounds A corresponds to an effluent comprising at least 80% or 90% by weight, preferably at least 95% by weight, very preferably at least 99% by weight, of compounds A.

[0041] The present invention can be defined as a method and a device comprising a sequence of unit operations making it possible to produce paraxylene and benzene.

[0042] The method and device according to the invention are characterized in that they comprise and use the catalytic units and separation units known to those skilled in the art for producing benzene and paraxylene, units which are usually found in aromatic complexes.

[0043] One of the features of the present invention can be summarized in the use of carbon monoxide (CO) and carbon dioxide (CO2), products of a pyrolysis, oxycombustion or gasification unit of hydrocarbon compounds to increase the production of aromatic compounds.

[0044] Specifically, the combination of a unit for converting a mixture comprising CO and CO2 into methanol followed by a unit for aromatizing the methanol and the introduction of aromatic compounds from the aromatization section into the aromatic complex makes it possible to significantly increase the quantity of aromatics produced by pyrolysis, oxycombustion or gasification of hydrocarbon compounds and to potentially recover all of the CO and CO2 produced. With reference to FIG. 1, according to one or more embodiments, the method for converting aromatic compounds comprises: an optional feed separation unit 1 for separating the first hydrocarbon feed 2 from the aromatic complex into a hydrocarbon cut with 7 carbon atoms or less (C7-) and an aromatic cut with 8 carbon atoms or more (A8+);an optional aromatics extraction unit 3 between the feed separation unit 1 and a fractionation train 4-7 for separating aliphatic compounds of benzene and toluene from the C7- cut of the complex feed; the fractionation train 4-7 downstream of the optional aromatics extraction unit 3 for extracting benzene, toluene and xylenes from the other aromatics; an optional transalkylation unit 8 converting toluene (and optionally benzene) and methylalkylbenzenes such as trimethylbenzenes into xylenes - advantageously this unit can also process tetramethylbenzenes; an optional selective hydrogenolysis unit 9 adapted to process a cut comprising aromatic compounds with 9 and 10 carbon atoms and produce a hydrogenolysis effluent enriched in methyl-substituted aromatic compounds;an optional separation unit (not shown) for separating the hydrogenolysis effluent arranged (eg directly) downstream of the selective hydrogenolysis unit 9, to produce a plurality of liquid effluent cuts; a xylene separation unit 10 (eg of the crystallization or LMS type using a molecular sieve and a desorbent such as toluene) for isolating paraxylene from the xylenes and ethylbenzene; an isomerization unit 11 for the raffinate obtained as effluent from the xylene separation unit 10 to convert in particular orthoxylene, metaxylene and ethylbenzene into paraxylene; an optional stabilization column 12, in particular for removing the more volatile species (eg C5-) of the aromatic complex, in particular from the effluents of the transalkylation unit 8 and / or the isomerization unit 11;synthesis gas production unit, such as a pyrolysis unit 13, preferably catalytic, or an oxycombustion or gasification unit 14, for treating a second hydrocarbon feedstock 30, making it possible to produce a synthesis gas 32 comprising CO, CO2 and optionally hydrogen and / or water; a methanol synthesis reaction section 50 for treating the synthesis gas 32 from the pyrolysis unit 13 or from the oxycombustion or gasification unit 14, and producing methanol 51; an optional first make-up line for providing a hydrogen supply 34 in the synthesis gas 32; an optional purification section 52 for treating the methanol, separating a water purge 53 and a recycle gas 54 comprising unconverted CO and / or unconverted CO2, and producing purified methanol 55;an aromatization reaction section 56 for treating methanol 51 or purified methanol 55 and producing a hydrocarbon effluent 57 comprising aromatic compounds; an optional separation section 58 for: treating the hydrocarbon effluent 57; separating water 61; separating a light gas purge 60 comprising hydrogen and C1-C2 hydrocarbon compounds; separating an optional recycle effluent 59 comprising C3-C4 hydrocarbon compounds and / or non-aromatic C5-C10 hydrocarbon compounds and optionally benzene and / or toluene; and producing an effluent enriched in aromatic compounds 62.;

[0045] According to one or more embodiments, the purification section 52 is adapted to recycle the recycle gas 54 to the inlet of the methanol synthesis reaction section 50.

[0046] According to one or more embodiments, the separation section 58 is adapted to recycle at least in part the recycle effluent 59 to the inlet of the aromatization reaction section 56.

[0047] Advantageously, the first hydrocarbon feedstock 2 is supplied by the hydrocarbon effluent 57 or the effluent enriched in aromatic compounds 62.

[0048] With reference to Figure 1, the feed separation unit 1 treats the first hydrocarbon feed 2 of the aromatic complex to separate a top cut comprising (eg essentially) compounds with 7 carbon atoms or less 16 (C7-) containing in particular benzene and toluene, and a bottom cut comprising (eg essentially) aromatics with 8 carbon atoms or more 17 (A8+) sent to the xylene column 6. According to one or more embodiments, the feed separation unit 1 also separates a first toluene cut 18 comprising at least 90% by weight, preferably at least 95% by weight, very preferably at least 99% by weight of toluene, relative to the total weight of the first toluene cut 18.According to one or more embodiments, the first toluene cut 18 is sent to the first aromatic compound distillation column 4, also called the benzene column, and / or to the second aromatic compound distillation column 5, also called the toluene column. According to one or more embodiments, the first hydrocarbon feedstock 2 is a hydrocarbon cut containing predominantly (i.e., > 50% by weight) molecules whose carbon number ranges from 6 to 10 carbon atoms. This feedstock may also contain molecules having more than 10 carbon atoms and / or molecules with 5 carbon atoms.

[0049] The first hydrocarbon feedstock 2 of the aromatic complex is rich in aromatics (eg > 50% by weight) and preferably contains at least 20% by weight of benzene, preferably at least 30% by weight, very preferably at least 40% by weight of benzene, relative to the total weight of the first hydrocarbon feedstock 2. The first hydrocarbon feedstock 2 can be produced by catalytic reforming of a naphtha or be a product of a cracking unit (eg steam, catalytic) or any other means of producing aromatic alkyls.

[0050] According to one or more embodiments, the first hydrocarbon feedstock 2 is at least partially or even entirely bio-sourced. According to one or more embodiments, the first hydrocarbon feedstock 2 comes (essentially) from a lignocellulosic biomass conversion process. For example, an effluent produced by conversion of lignocellulosic biomass can be treated to meet the required specifications of the first hydrocarbon feedstock 2 in order to have contents of sulfur, nitrogen and oxygenated elements compatible with an aromatic complex.

[0051] According to one or more embodiments, the first hydrocarbon feedstock 2 of the aromatic complex comprises at least 25% by weight, preferably at least 30% by weight, very preferably at least 35% by weight, of hydrocarbon effluent 57 (or effluent enriched in aromatic compounds 62) and optionally of pyrolysis effluent 31, relative to the total weight of the first hydrocarbon feedstock 2. According to one or more embodiments, the first hydrocarbon feedstock 2 of the aromatic complex is substantially constituted of the hydrocarbon effluent 57 (or effluent enriched in aromatic compounds 62) and optionally of the pyrolysis effluent 31. According to one or more embodiments, the first hydrocarbon feedstock 2 may comprise a mixture of biosourced aromatic and paraffinic compounds and a mixture of non-biosourced aromatic and paraffinic compounds (for example originating from a catalytic reforming unit).

[0052] According to one or more embodiments, the first hydrocarbon feedstock 2 comprises less than 10 ppm by weight, preferably less than 5 ppm by weight, very preferably less than 1 ppm by weight of elemental nitrogen, and / or less than 10 ppm by weight, preferably less than 5 ppm by weight, very preferably less than 1 ppm by weight of elemental sulfur, and / or less than 100 ppm by weight, preferably less than 50 ppm by weight, very preferably less than 10 ppm by weight of elemental oxygen.

[0053] According to one or more embodiments, the overhead cut 16, optionally mixed with the bottom product (benzene and toluene) from the stabilization column 12 defined below, is sent to the aromatics extraction unit 3 in order to extract an effluent comprising C6-C7 aliphatic species 19 which is exported as a co-product of the aromatic complex or at least partly recycled in the aromatization reaction section 56. The aromatic cut 20 (essentially benzene and toluene) called extract from the aromatics extraction unit 3, optionally mixed with the heavy fraction 21 from the transalkylation unit 8 defined below, is sent to the fractionation train, preferably in the benzene column 4. According to one or more embodiments, the aromatic cut 20 is a hydrocarbon feedstock (eg essentially) aromatic in C6-C7 (A6-A7).

[0054] According to one or more embodiments, the overhead cut 16 from the charge separation unit 1, optionally mixed with the heavy fraction 21 from the transalkylation unit 8 defined below, is sent directly to the fractionation train, preferably in the benzene column 4 (without treatment by the aromatics extraction unit 3).

[0055] According to one or more embodiments, the fractionation train comprises the aromatic compound distillation columns 4, 5, 6 and 7 making it possible to separate the following five cuts: a cut comprising (e.g. essentially) benzene 22; a cut comprising (e.g. essentially) toluene 23; a cut comprising (e.g. essentially) xylenes and ethylbenzene 24; a cut comprising (e.g. essentially) aromatic compounds with 9 and 10 carbon atoms 25; a cut comprising (e.g. essentially) aromatic compounds whose most volatile species are aromatics with 10 carbon atoms 26.

[0056] The benzene column 4 is suitable for: treating the aromatic cut 20 which is a hydrocarbon feedstock (e.g. essentially) aromatic in C6-C10 (A6+); producing at the top the cut comprising benzene 22 which can be one of the products sought at the outlet of the aromatic complex; and producing at the bottom an effluent (e.g. essentially) aromatic in C7-C10 27 (A7+).

[0057] The toluene column 5 is suitable for: treating the C7-C10 aromatic effluent 27 (A7+), the bottom product of the benzene column 4; producing at the top the cut comprising toluene 23 which is directed to the transalkylation unit 8; and producing at the bottom an effluent (e.g. essentially) C8-C10 aromatic effluent 28 (A8+).

[0058] The third aromatic compound distillation column 6, also called xylene column, is suitable for: treating the aromatic cut with 8 carbon atoms or more 17 (A8+) of the first hydrocarbon feedstock 2 and optionally the bottom effluent from the toluene column 28; producing at the top the cut comprising xylenes and ethylbenzene 24 which is directed to the xylene separation unit 10; and producing at the bottom an effluent (eg essentially) comprising C9-C10 aromatics 29 (A9+).

[0059] The fourth column for distillation of aromatic compounds 7, also called the heavy aromatics column, is optional and is suitable for: treating the bottom effluent from the xylene column 29; producing at the top the fraction comprising C9-C10 monoaromatics 25; and producing at the bottom the cut comprising (eg essentially) aromatic compounds whose most volatile species are aromatics with 10 carbon atoms 26 (A10+). Preferably, the bottom cut 26 comprises C11+ compounds.

[0060] In the transalkylation unit 8, the fraction comprising C9-C10 monoaromatics 25 (and / or the hydrogenolysis effluent enriched in methyl-substituted aromatic compounds described below) is mixed with the cut comprising toluene 23 from the top of the toluene column 5, and feeds the reaction section of the transalkylation unit 8 to produce xylenes by transalkylation of aromatics lacking methyl groups (toluene), and in excess of methyl groups (e.g. tri- and tetra-methylbenzenes). According to one or more embodiments, the transalkylation unit 8 is fed with benzene (line not shown in FIG. 1), for example when an excess of methyl groups is observed for the production of paraxylene. According to one or more embodiments, the transalkylation unit 8 directly treats the bottom effluent from the xylene column 29.

[0061] According to one or more embodiments, the transalkylation unit 8 comprises at least one first transalkylation reactor adapted to be used in at least one of the following operating conditions: temperature between 200°C and 600°C, preferably between 350°C and 550°C, and more preferably still between 380°C and 500°C; pressure between 2 MPa and 10 MPa, preferably between 2 MPa and 6 MPa, and more preferably between 2 MPa and 4 MPa;

[0062] PPH between 0.5 h -1 and 5 a.m. -1 , preferably between 1 h -1 and 4 a.m. -1 , and more preferably between 2 h' 1 and 3 a.m. 1 .

[0063] According to one or more embodiments, the first transalkylation reactor is operated in the presence of a catalyst comprising zeolite, for example ZSM-5. According to one or more embodiments, the second transalkylation reactor is of the fixed bed type.

[0064] According to one or more embodiments, the effluents from the reaction section of the transalkylation unit 8 are separated in a first separation column (not shown) downstream of said reaction section of the transalkylation unit 8. A cut comprising at least a portion of the benzene and the more volatile species 38 (C6-) is extracted at the top of the first separation column and is sent to an optional stabilization column 12, making it possible in particular to remove the more volatile species (eg C5-) from the aromatic complex. The heavy fraction 21 of the effluents from the first separation column comprising (eg essentially) aromatics with at least 7 carbon atoms (A7+), is optionally recycled to the fractionation train 4-7, for example to the benzene column 4.

[0065] The fraction comprising xylenes and ethylbenzene 24 is treated in the xylene separation unit 10 to produce a fraction or extract 39 comprising paraxylene and a raffinate 40. The extract 39 can then be distilled (e.g. if separation by LMS adsorption), for example by means of an extract column and then an additional toluene column (not shown) in the case where toluene is used as a desorbent, to obtain high-purity paraxylene exported as the main product. The raffinate 40 from the xylene separation unit 10 comprises (e.g. essentially) orthoxylene, metaxylene and ethylbenzene and feeds the isomerization unit 11.

[0066] According to one or more embodiments, the xylene separation unit 10 also separates a second toluene cut 41 comprising at least 90% by weight, preferably at least 95% by weight, very preferably at least 99% by weight of toluene, relative to the total weight of the second toluene cut 41. The toluene cut 41 may be, for example, a portion of the toluene used as a desorbent when the xylene separation unit 10 comprises an LMS adsorption unit. According to one or more embodiments, the second toluene cut 41 is sent to the transalkylation unit 8.

[0067] In the isomerization reaction section of the isomerization unit 11, the paraxylene isomers are isomerized while the ethylbenzene can be: isomerized into a mixture of C8 aromatics, for example if it is desired to produce mainly paraxylene; and / or dealkylated to produce benzene, for example if it is desired to produce both paraxylene and benzene. According to one or more embodiments, the effluents from the isomerization reaction section are sent to a second separation column (not shown) to produce at the bottom an isomerate 42 enriched in paraxylene preferably recycled to the xylene column 6; and to produce at the top a hydrocarbon cut comprising compounds with 7 carbon atoms or less 43 (C7-) sent to the optional stabilization column 12, for example with the cut comprising at least a portion of the benzene and the more volatile species 38.

[0068] According to one or more embodiments, the isomerization unit 11 comprises a first isomerization zone working in the liquid phase, and / or a second isomerization zone working in the gas phase. According to one or more embodiments, the isomerization unit 11 comprises a first isomerization zone working in the liquid phase, and a second isomerization zone working in the gas phase. According to one or more embodiments, a first portion of the raffinate 40 is sent to the liquid-phase isomerization unit, to obtain a first isomerate directly and at least partially feeding the separation unit 10, and a second portion of the raffinate 40 is sent to the gas-phase isomerization unit to obtain an isomerate which is sent to the xylene column 6.

[0069] According to one or more embodiments, the gas phase isomerization zone is suitable for use under at least one of the following operating conditions: temperature above 300°C, preferably from 350°C to 480°C; pressure below 4.0 MPa, and preferably from 0.5 MPa to 2.0 MPa; hourly space velocity below 10 h -1 (10 liters per liter per hour), preferably between 0.5 h' 1 and 6 a.m. 1 ; hydrogen to hydrocarbon molar ratio less than 10, and preferably between 3 and 6; presence of a catalyst comprising at least one zeolite having channels whose opening is defined by a ring with 10 or 12 oxygen atoms (10 MR or 12 MR), and at least one metal from group VIIIB with a content of between 0.1 and 0.3% by weight (reduced form), limits included, relative to the total weight of the catalyst.

[0070] According to one or more embodiments, the liquid phase isomerization zone is suitable for use under at least one of the following operating conditions: temperature below 300°C, preferably 200°C to 260°C; pressure below 4 MPa, preferably 2 MPa to 3 MPa; hourly space velocity (WH) below 10 h -1 (10 liters per liter per hour), preferably between 2 h -1 and 4 a.m. -1 ; presence of a catalyst comprising at least one zeolite having channels whose opening is defined by a ring with 10 or 12 oxygen atoms (10 MR or 12 MR), preferably a catalyst comprising at least one zeolite having channels whose opening is defined by a ring with 10 oxygen atoms (10 MR), and even more preferably a catalyst comprising a ZSM-5 type zeolite.

[0071] The term WH corresponds to the volume of hourly hydrocarbon charge injected relative to the volume of catalyst charged.

[0072] According to one or more embodiments, the optional stabilization column 12 produces: at the bottom a stabilized cut comprising (eg essentially) benzene and toluene 44 optionally recycled at the inlet of the charge separation unit 1 and / or the aromatic extraction unit 3; and at the top a cut of more volatile species 45 (eg C5-) removed from the aromatic complex.

[0073] According to one or more embodiments, the selective hydrogenolysis unit 9 is suitable for: treating mono-aromatics having between 9 and 10 carbon atoms 25; and producing a hydrogenolysis effluent enriched in methyl-substituted aromatic compounds 46.

[0074] Specifically, the selective hydrogenolysis unit 9 can be adapted to treat aromatics having between 9 and 10 carbon atoms 25 by transforming one or more alkyl group(s) with at least two carbon atoms (ethyl, propyl, butyl, isopropyl groups, etc.) attached to a benzene ring, into one or more methyl group(s), i.e. formed from a single CH3 group. The major interest of the selective hydrogenolysis unit 9 is to increase the content of CH3 groups and lower the content of ethyl, propyl, butyl, isopropyl groups, etc., in the feed of the isomerization unit 11 to increase the rate of production of xylenes, and in particular paraxylene, in said isomerization unit 11.

[0075] According to one or more embodiments, the selective hydrogenolysis unit 9 comprises at least one hydrogenolysis reactor adapted to be used in at least one of the following operating conditions: temperature between 300°C and 550°C, preferably between 350°C and 500°C, and more preferably still between 370°C and 450°C; pressure between 0.1 MPa and 3 MPa, preferably between 0.2 MPa and 2 MPa, and more preferably between 0.2 MPa and 1 MPa; H2 / HC (hydrocarbon feed) molar ratio between 1 and 10, and preferably between 1.5 and 6;

[0076] PPH between 0.1 h -1 and 50 h -1 (eg 0.5-50 h -1 ), preferably between 0.5 h -1 and 30 h -1 (eg 1-30 h -1 ), and more preferably between 1 h -1 and 8 p.m. -1 (eg 2-20 h' 1 , 5-8 p.m. 1 ).

[0077] According to one or more embodiments, the hydrogenolysis reactor is operated in the presence of a catalyst comprising at least one metal from group VI 11 B of the periodic table, preferably nickel and / or cobalt, deposited on a porous support comprising at least one crystalline or non-crystalline refractory oxide, with structured or non-structured porosity. According to one or more embodiments, the metal from group VII IB is nickel. The presence of a promoter (Group VIB VI IB VIIIB IB IIB) is also possible. The catalyst is supported on a refractory oxide (e.g. alumina, silica), optionally treated with a base to neutralize it. According to one or more embodiments, the hydrogenolysis reactor is of the fixed bed type, and the catalyst support is in the form of extrudates. According to one or more embodiments, the hydrogenolysis reactor is of the moving bed type, and the catalyst support is in the form of approximately spherical beads.A moving bed can be defined as a gravity-flow bed, such as those encountered in the catalytic reforming of gasolines.

[0078] According to one or more embodiments, the second hydrocarbon feedstock 30 is a mixture of hydrocarbon compounds having an elemental oxygen content greater than 1% by weight, preferably greater than 3% by weight, very preferably greater than 5% by weight relative to the total weight of said second hydrocarbon feedstock 30. According to one or more embodiments, the second hydrocarbon feedstock 30 comprises or consists of lignocellulosic biomass or one or more constituents of lignocellulosic biomass chosen from the group formed by cellulose, hemicellulose and lignin.

[0079] Lignocellulosic biomass can consist of wood, agricultural waste or plant waste. Other non-limiting examples of lignocellulosic biomass material are agricultural residues (straw, corn stalk, etc.), forestry residues (first thinning products), forestry products, dedicated crops (short rotation coppice), residues from the agri-food industry, household organic waste, waste from wood processing facilities, used construction wood, and paper, whether recycled or not.

[0080] Lignocellulosic biomass can also come from by-products of the paper industry such as Kraft lignin, or black liquor from paper pulp production.

[0081] The lignocellulosic biomass may advantageously undergo at least one pretreatment step before its introduction into the process according to the invention. Preferably, the biomass is ground and dried, until the desired particle size is obtained. A feedstock having a particle diameter of between 0.3 and 0.5 mm may advantageously be obtained. Typically, the particle size of the lignocellulosic biomass is a particle size sufficient to pass through a 1 mm sieve up to a particle size sufficient to pass through a 30 mm sieve.

[0082] According to one or more embodiments, when the second hydrocarbon feedstock 30 is solid (e.g. biomass type feedstock), the second hydrocarbon feedstock 30 is advantageously loaded into a pneumatic drive or transport compartment so as to be driven into a pyrolysis or oxycombustion reactor or a gasification furnace by a drive fluid. Preferably, the drive fluid used is nitrogen gas. However, it is also envisaged that other non-oxidizing drive fluids may be used. Preferably, synthesis gas produced during the process may be recycled and used as a drive fluid. Said synthesis gas is mainly composed of a non-condensable gaseous effluent comprising at least carbon monoxide (CO) and carbon dioxide (CO2) and also advantageously comprising light olefins comprising from 2 to 4 carbon atoms.In this way, the costs of carrying out pyrolysis or oxycombustion or gasification can be considerably reduced. The second hydrocarbon feedstock 30 can be loaded into a feed hopper or other device which allows said feedstock to be brought into the drive compartment in an appropriate quantity. In this way, a constant quantity of feedstock is delivered into the drive compartment.

[0083] The drive fluid advantageously transports the second hydrocarbon feedstock 30 from the drive compartment into the pyrolysis or oxycombustion reactor or the gasification furnace through a feed tube.

[0084] Typically, the feed tube is cooled to maintain the temperature of the second hydrocarbon feedstock 30 at a required level prior to its entry into the pyrolysis or oxy-combustion reactor or the gasification furnace. The feed tube may be cooled by lining the tube, typically with an air-cooled or liquid-cooled jacket. However, it is also contemplated that the feed tube will not be cooled.

[0085] According to one or more embodiments, the pyrolysis unit 13 comprises at least one pyrolysis reactor (e.g. fluidized bed) suitable for use in at least one of the operating conditions listed below.

[0086] According to one or more embodiments, the pyrolysis step is carried out at a temperature between 400°C and 1000°C, preferably between 400°C and 650°C, preferably between 450°C and 600°C and preferably between 450°C and 590°C. In particular, the use of hot regenerated catalyst from a catalyst regeneration step can ensure reactor temperature ranges.

[0087] The pyrolysis step is also advantageously carried out at an absolute pressure of between 0.1 MPa and 0.5 MPa and at a WH of between 0.01 h -1 and 10 a.m. 1 , preferably between 0.01 h' 1 and 5 a.m. 1 , and very preferably between 0.1 h' 1 and 3 a.m. 1 . The WH is the ratio of the volume flow rate of charge to the volume of catalyst used.

[0088] According to one or more embodiments, the pyrolysis step is catalytic and carried out in the presence of a catalyst. Preferably, said step operates in the presence of a zeolite catalyst comprising and preferably consisting of at least one zeolite chosen from ZSM-5, ferrierite, Beta zeolite, Y zeolite, mordenite, ZSM-23, ZSM-57, EU-1, ZSM-11 and preferably the catalyst is a catalyst comprising only ZSM-5. The zeolite used in the catalyst used in the catalytic pyrolysis step can advantageously be doped preferably with a metal chosen from iron, gallium, zinc and lanthanum.

[0089] Under these conditions, the second hydrocarbon feedstock 30 will first undergo rapid pyrolysis in the reactor by contacting the hot catalyst from the regenerator which in this stage acts as a thermal vector. The gases resulting from this pyrolysis will then react on the catalyst which this time plays its role as a catalyst to catalyze the reactions producing the desired chemical intermediates.

[0090] In the pyrolysis unit 13, the second hydrocarbon feedstock 30 is in particular converted at least partially into a pyrolysis effluent 31 comprising hydrocarbon compounds whose carbon number ranges from 6 to 10 carbon atoms. The pyrolysis effluent 31 preferably feeds the first hydrocarbon feedstock 2 of the aromatic complex. The pyrolysis unit 13 also produces a synthesis gas 32 comprising CO, CO2 and optionally hydrogen, and by-products 33.

[0091] The products obtained at the end of the pyrolysis step are advantageously recovered in the form of a gaseous effluent comprising BTX.

[0092] Said gaseous effluent comprising the products obtained at the end of the pyrolysis step is then advantageously sent to a fractionation section so as to separate at least the following cuts: a gaseous fraction of incondensables, comprising at least CO and CO2, a liquid cut called BTX, comprising hydrocarbon compounds whose carbon number ranges from 6 to 10 carbon atoms, a liquid cut mainly comprising compounds having a number of carbon atoms greater than 9, i.e. at least 50% by weight of C9+ compounds, and water.

[0093] Said gaseous fraction of incondensables may also advantageously comprise light olefins comprising from 2 to 4 carbon atoms.

[0094] The coked catalyst and the second unconverted hydrocarbon feedstock usually referred to as "char" are advantageously withdrawn from the reactor and preferably sent to a stripper so as to remove potentially adsorbed hydrocarbons and thus prevent their combustion in the regenerator, by contacting with at least one gas chosen from water vapor, an inert gas such as, for example, nitrogen, and a portion of the gaseous fraction of incondensables resulting from the fractionation of the gaseous effluent from the pyrolysis step. Said coked catalyst and the second unconverted hydrocarbon feedstock, optionally stripped, are advantageously sent to a regenerator where coke and char are burned by adding air or oxygen, thus producing regenerated catalyst and a CO2-rich combustion gas.

[0095] According to one or more embodiments, the regenerated catalyst is advantageously recycled into the reactor of the pyrolysis stage in order to undergo another cycle.

[0096] Advantageously, the pyrolysis step of the process according to the invention allows the production of at least 10% by weight and preferably at least 15% by weight of aromatics relative to the total mass of the reaction products obtained, with a selectivity of at least 65% and preferably at least 70% in BTX.

[0097] The pyrolysis step also produces at least one BTX cut (pyrolysis effluent 31) and a gaseous fraction of incondensables (synthesis gas 32) comprising at least CO and CO2.

[0098] The process also makes it possible to obtain, in addition to the BTX cut, a heavier liquid fraction, mainly aromatic, called the “C9+ cut” which can advantageously be used in a process external to the process according to the invention.

[0099] Preferably, at least a portion of the gaseous fraction of incondensables is recycled, preferably via a compressor, into the reactor of the pyrolysis stage. This gaseous flow then serves as a fluid for carrying the charge in said reactor. In this case, a purge of said recycled gaseous effluent is preferably carried out, preferably either upstream or downstream of said compressor.

[0100] According to one or more embodiments, the pyrolysis effluent 31 is a hydrocarbon fraction containing predominantly (i.e., > 50% by weight) molecules whose carbon number ranges from 6 to 10 carbon atoms. The pyrolysis effluent 31 may also contain molecules having more than 10 carbon atoms and / or molecules with 5 carbon atoms. The pyrolysis effluent 31 is rich in aromatics (e.g., > 50% by weight) and preferably contains at least 20% by weight of benzene, preferably at least 30% by weight, very preferably at least 40% by weight of benzene, relative to the total weight of the pyrolysis effluent 31. According to one or more embodiments, the pyrolysis effluent 31 is treated to meet the required specifications of the first hydrocarbon feedstock 2 as described above in order to have contents of sulfur, nitrogen and oxygenated elements compatible with an aromatic complex.

[0101] According to one or more embodiments, the synthesis gas 32 (leaving the pyrolysis unit 13) comprises at least a portion of the gaseous fraction of incondensables and preferably comprises at least in part the combustion gas rich in CO2. According to one or more embodiments, the synthesis gas 32 produced by the pyrolysis unit 13 comprises a mixture containing predominantly (e.g. comprising at least 50% by weight) CO and CO2. According to one or more embodiments, the synthesis gas 32 comprises at least 20% by weight of CO, preferably at least 30% by weight of CO, very preferably at least 40% by weight of CO (e.g. at least 50% by weight of CO), relative to the total weight of the synthesis gas 32.According to one or more embodiments, the synthesis gas 32 comprises at least 0.2% by weight of hydrogen, preferably at least 0.5% by weight of hydrogen, very preferably at least 0.8% by weight of hydrogen, relative to the total weight of the synthesis gas 32. According to one or more embodiments, the synthesis gas 32 at the outlet of the pyrolysis unit 13 contains at least 20% by weight of CO2, relative to the total weight of the synthesis gas 32. According to one or more embodiments, the synthesis gas 32 at the outlet of the pyrolysis unit 13 contains approximately 30% (eg ± 10% by weight) by weight of CO2, relative to the total weight of the synthesis gas 32. According to one or more embodiments, the synthesis gas 32 contains methane, ethylene and propylene (eg less than 10% by weight) as well as ethane, propane and water. (eg less than 3% by weight).

[0102] According to one or more embodiments, the by-products 33 comprise the C9+ fraction mainly consisting of more or less alkylated di and tri aromatics. This cut can be used directly as bunker fuel, for example, or undergo hydrotreatment and / or hydrocracking to improve its properties and use it as Jet Fuel or diesel.

[0103] In the oxycombustion or gasification unit 14, the second feedstock 30 is converted into a synthesis gas comprising CO, CO2 and optionally water.

[0104] According to one or more embodiments, the oxycombustion unit 14 comprises at least one reactor used in at least one of the following operating conditions: a reactor operating in a fluidized bed; temperature between 500°C and 1000°C; pressure between 0.1 MPa and 3 MPa, preferably between 0.1 MPa and 1 MPa.

[0105] According to one or more embodiments, the oxycombustion step is carried out in the presence / by injection of a gas source comprising at least 80% by weight of oxygen, preferably at least 90% by weight of oxygen, very preferably at least 95% by weight of oxygen, relative to the total weight of the gas source. According to one or more embodiments, the gas source is a source of pure oxygen, such as a gas comprising at least 99% by weight of oxygen, preferably at least 99.5% by weight of oxygen relative to the total weight of the gas source. The control of the temperature of the hearth can be carried out by adjusting the O2 concentration at the reactor inlet. This adjustment of the O2 concentration can be done via the recycling of combustion fumes. According to one or more embodiments, the gasification unit 14 comprises at least one gasification furnace used under at least one of the following operating conditions: temperature between 700°C and 1400°C.

[0106] According to one or more embodiments, the synthesis gas 32 (leaving the oxycombustion or gasification unit 14) comprises a mixture containing mainly (e.g. comprising at least 50% by weight) CO and CO2. According to one or more embodiments, the synthesis gas 32 comprises at least 70% by weight of CO2, preferably at least 75% by weight of CO2, relative to the total weight of the synthesis gas 32. According to one or more embodiments, the synthesis gas 32 comprises less than 4% by weight of CO, preferably less than 2% by weight of CO, relative to the total weight of the synthesis gas 32. According to one or more embodiments, the synthesis gas 32 comprises water, such as for example at least 18% by weight of water, preferably at least 20% by weight of water, relative to the total weight of the synthesis gas 32.

[0107] According to one or more embodiments, a hydrogen supply 34 supplied by a make-up line is added to the synthesis gas 32 so that the molar ratio H2 / (CO+CO2) of the synthesis gas 32 at the inlet of the methanol synthesis reaction section 50 is between 3 and 10, preferably between 3 and 8, preferably between 3 and 7, preferably between 3 and 6, very preferably between 3 and 5. The make-up hydrogen can advantageously come from any process allowing the production of hydrogen, such as for example a steam reforming process or a catalytic reforming process, the electrolysis of water, the dehydrogenation of alkanes, and its hydrogen purity is most often between 75 and 99.9% volume. It is understood that the hydrogen supply 34 can be supplied directly into the methanol synthesis reaction section 50 and then mixed with the synthesis gas 32.

[0108] In the methanol synthesis reaction section 50, the synthesis gas 32, preferably enriched with a hydrogen supply 34, is converted at least partially into methanol and water. The methanol synthesis reaction from CO2 and CO is well known to those skilled in the art (see for example: US5631302, US4238403, EP 3402 773, and Renewable Energy, 146 (2020), 1192-1203).

[0109] According to one or more embodiments, the methanol synthesis reaction section 50 comprises at least one reactor used under at least one of the following operating conditions: temperature between 200°C and 450°C, preferably between 220°C and 400°C, and more preferably still between 250°C and 350°C; pressure between 1 MPa and 12 MPa, preferably between 2 MPa and 10 MPa, and more preferably between 5 MPa and 10 MPa; H2 / COx (CO and CO2) molar ratio between 3 and 10, preferably between 3 and 7, very preferably between 3 and 5; space velocity of the gas at the reactor inlet between 0.2 g / g ca ta / h and 1 g / g ca your / h.

[0110] According to one or more embodiments, the reactor of the methanol synthesis reaction section 50 is adapted to operate in a fluid bed or fixed bed, preferably in a fixed bed. 2

[0111] According to one or more embodiments, the methanol synthesis reaction is carried out in the presence of a hydrogenation catalyst. According to one or more embodiments, said catalyst is a catalyst for the hydrogenation of CO2. According to one or more embodiments, the catalyst for the hydrogenation of CO2 comprises copper (e.g. in oxide form) and optionally at least one promoter chosen from the following elements: Zn, Zr, Si, Al, Ti, Cr, Ga, Ce (e.g. in oxide form), and optionally a support (e.g. a refractory oxide such as alumina). According to one or more embodiments, the catalyst for the hydrogenation of CO2 is of the CuO / ZnO / AhCh type. According to one or more embodiments, the catalyst for the hydrogenation of CO2 comprises 50-75% by weight of CuO, 15-35% by weight of ZnO and 5-20% of AI2O3, relative to the total weight of the catalyst.

[0112] According to one or more embodiments, the synthesis gas 32 can be purified before being introduced into the methanol synthesis reaction section 50. The purification of the synthesis gas aims to remove sulfur compounds, nitrogen compounds, halogens, heavy metals and transition metals. The main technologies for purifying synthesis gases are: adsorption, absorption, catalytic reactions.

[0113] The various purification methods are well known to those skilled in the art; reference may be made, for example, to: Oil & Gas Science and Technology - Rev. IFP Energies nouvelles, 68 (2013), No. 4; and to Applied Energy, 237 (2019), 227-240.

[0114] In the optional purification section 52, the methanol 51 is treated to separate water 53 and a recycle gas 54 comprising unconverted CO and / or unconverted CO2, and to produce purified methanol 55. The recycle gas 54 is preferably recycled to the inlet of the methanol synthesis reaction section 50. The water-methanol separation can be carried out by distillation. According to one or more embodiments, the purified methanol 55 comprises at least 99.1% by weight of methanol. According to one or more embodiments, the water 53 comprises at least 99.99% by weight of water. Water 53, a co-product of the methanol synthesis reaction, is purged and removed from the process or sent to an electrolyzer to produce hydrogen or used upstream of the pyrolysis unit 13 or the oxycombustion or gasification unit^ for biomass pretreatment operations.

[0115] According to the invention, methanol 51 or purified methanol 55 is sent to the aromatization reaction section 56 to treat the methanol and produce aromatic compounds. According to one or more embodiments, the aromatization reaction section 56 comprises at least one reactor used under at least one of the following operating conditions: temperature between 250°C and 500°C, preferably between 300°C and 450°C, and more preferably still between 350°C and 420°C; pressure between 0.1 MPa and 1 MPa, preferably between 0.2 MPa and 0.8 MPa, and more preferably between 0.4 MPa and 0.5 MPa; space velocity of the gas at the reactor inlet between 0.2 and 1 g / g ca t a / h.

[0116] According to one or more embodiments, the reactor of the aromatization reaction section 56 is adapted to operate in a fluid bed.

[0117] According to one or more embodiments, the aromatization reaction is carried out in the presence of an aromatization catalyst. According to one or more embodiments, said catalyst is a catalyst for the aromatization of methanol. According to one or more embodiments, the catalyst for the aromatization of methanol comprises zinc optionally impregnated on a zeolite (eg ZSM-5), the zeolite being optionally arranged on a support (eg a refractory oxide such as alumina). According to one or more embodiments, the catalyst for the aromatization of methanol is of the Zn-ZSM-δ / AhCh type, and preferably comprises between 0.1% by weight and 10% by weight, such as between 1% by weight and 5% by weight of Zn, relative to the total weight of the catalyst. Examples of such catalysts are described in Journal of Catalysis, 394 (2021), 416-428, and in Catalysis Today, 233 (2014), 8-13.

[0118] At the outlet of the aromatization reaction section 56, four streams can be separated: an effluent enriched in aromatic compounds 62 which is sent to the charge separation unit 1 in a mixture with the first hydrocarbon charge 2; a recycle effluent 59 comprising C3-C4 hydrocarbon compounds and / or non-aromatic C5-C10 hydrocarbon compounds, which is recycled to the inlet of the aromatization reaction section 56; a water stream 61 purged at the outlet of the aromatization reaction section 58, potentially sent to an electrolyzer to produce hydrogen or used upstream of the pyrolysis unit 13 or the oxycombustion or gasification unit 14 for biomass pretreatment operations; and a light gas purge 60 comprising hydrogen and C1-C2.

[0119] According to one or more embodiments, the recycle effluent 59 comprises benzene and / or toluene.

[0120] Advantageously, the combination of a methanol synthesis reaction section 50, followed by an aromatization section 56 makes it possible to produce additional aromatics from CO and CO2, products of the pyrolysis unit 13 or the oxycombustion or gasification unit 14.

[0121] The method and device according to the invention thus make it possible to obtain gains of up to 350% by weight in aromatic compounds, in particular when the CO2 formed by the combustion of the coke present on the pyrolysis catalyst is also treated.

[0122] In this application, the groups of chemical elements are given by default according to the CAS classification (CRC Handbook of Chemistry and Physics, publisher CRC press, editor-in-chief DR Lide, 81st edition, 2000-2001). For example, group VI II B according to the CAS classification corresponds to the metals of columns 8, 9 and 10 according to the new IIIPAC classification; group VI B according to the CAS classification corresponds to the metals of column 6 according to the new IIIPAC classification.

[0123] Examples

[0124] Example 1 of reference process

[0125] Example 1 of a reference process for transforming a feedstock comprising a mixture of aromatic compounds from a lignocellulosic biomass conversion process based on catalytic pyrolysis conversion is used.

[0126] Reference Process Example 1 is similar to the process shown in Figure 1 except that the transalkylation unit 8 is replaced by a disproportionation unit. In addition, Reference Process Example 1 does not use the following units: heavy aromatics column 7; selective hydrogenolysis unit 9; stabilization column 12; methanol synthesis reaction section 50; purification section 52; separation section 58; and aromatization reaction section 56.

[0127] The flow rates of said aromatic compounds of the charge to be treated, at the inlet of the reference process are as follows: benzene: 2.63 t / h; toluene: 5.64 t / h; ethyl benzene: 0.15 t / h; and xylenes: 3.56 t / h. That is a total of 11.98 t / h of aromatic compounds.

[0128] Furthermore, the pyrolysis reaction section produces CO and CO2, which are not converted into other chemical compounds. The flow rate of CO produced is 22.25 t / h, the flow rate of CO2 is 15.99 t / h. The combustion of the coke present on the pyrolysis catalyst produces 67 t / h of CO2. This gives a total flow rate of unused CO2 of 82.99 t / h.

[0129] In the reference process, all the toluene is converted by a disproportionation unit into benzene and xylenes. The xylenes from the feed and produced by disproportionation are isomerized into paraxylene, which is separated from the mixture of xylenes at thermodynamic equilibrium at the outlet of the isomerization unit, by means of an adsorption unit in LMS. This set of unit operations allows, in the best case (assuming a selectivity of 100% for each unit operation) to produce the following compounds: benzene: 5.02 t / h; paraxylene: 6.96 t / h; total aromatics: 11.98 t / h.

[0130] Example 2 of the process according to the invention

[0131] Example 2 of the process according to the invention makes it possible to increase the total quantity of aromatics produced for the same flow rate of biomass feed at the inlet of the pyrolysis unit 13 as in the reference process, and in particular to increase the quantity of paraxylene produced.

[0132] Compared to the diagram of the reference process, the methanol synthesis reaction section 50 and the purification section 52 are added in particular with the recycling of the recycle gas 54 (unconverted CO2+CO) from the purification section 52 to the inlet of the methanol synthesis reaction section 50. In this example 2, a hydrogen supply 34 is added to the inlet of the methanol synthesis reaction section 50. A water purge 53 also makes it possible to eliminate the water by-product of the methanol synthesis.

[0133] Also added are the aromatization reaction section 56, the separation section 58, two purge lines for water 61 and light gas purge 60, and a recycle line for sending the recycle effluent 59 to the inlet of the aromatization reaction section 56.

[0134] The synthesis gas 32, containing CO and CO2 produced by the pyrolysis unit 13, and the CO2 resulting from the combustion of the coke present on the pyrolysis catalyst, are introduced into the methanol synthesis reaction section 50, with a hydrogen supply 34. At the outlet of the purification section 52, the purified methanol 55 is introduced into an aromatization reaction section 56. At the outlet of the separation section 58: the recycle effluent 59 is recycled to the inlet of the aromatization reaction section 56, water is purged 61, light gases are purged 60, and the effluent enriched in aromatic compounds is sent to the inlet of the aromatic complex.

[0135] The conversion of CO and CO2 using this process can be complete. The water formed can be advantageously used in an electrolyzer upstream of the pyrolysis unit 13 for biomass pretreatment operations.

[0136] The overall material balances of the reference processes and those according to the invention are compared in Table 1.

[0137] Table 1

[0138] Table 1 shows that the implementation according to the invention makes it possible to produce significantly more aromatics (44.66 t / h instead of 11.98 t / h). This increase in aromatic compounds mainly concerns paraxylene, which increases from 6.96 t / h to 42.55 t / h. A quantity of water equal to 82.2 t / h is also produced; it can be used in the biomass pretreatment stages upstream of the pyrolysis unit.

Claims

Claims 1. A method for converting a first hydrocarbon feedstock comprising aromatic compounds, comprising the following steps: fractionating the first hydrocarbon feedstock (2) in a fractionation train (4-7) to extract at least one cut comprising benzene (22), one cut comprising toluene (23) and one cut comprising xylenes and ethylbenzene (24); separating the cut comprising xylenes and ethylbenzene (24) in a xylene separation unit (10) and producing an extract (39) comprising paraxylene and a raffinate (40) comprising orthoxylene, metaxylene and ethylbenzene; isomerizing the raffinate (40) in an isomerization unit (11) and producing an isomerate (42) enriched in paraxylene; sending the isomerate (42) enriched in paraxylene to the fractionation train (4-7); treating a second hydrocarbon feedstock (30) in a synthesis gas production unit (13;14) to produce a synthesis gas (32) comprising at least CO and CO2; treating the synthesis gas (32) in a methanol synthesis reaction section (50) to produce methanol (51); treating at least in part the methanol (51) in an aromatization reaction section (56) to produce a hydrocarbon effluent (57) comprising aromatic compounds; and feeding the first hydrocarbon feedstock (2) at least in part with the hydrocarbon effluent (57).; 2. A conversion process according to claim 1, comprising treating methanol (51) in a purification section (52) to separate water (53) and produce purified methanol (55).

3. Conversion method according to claim 2, wherein the purification section (52) is adapted to separate a recycle gas (54) comprising unconverted CO and / or unconverted CO2, and recycle the recycle gas (54) to the inlet of the methanol synthesis reaction section (50).

4. Conversion method according to any one of the preceding claims, in which the synthesis gas production unit (13; 14) comprises a pyrolysis unit (13) adapted to produce at least one pyrolysis effluent (31) comprising hydrocarbon compounds of 6 to 10 carbon atoms at least partially feeding the first hydrocarbon feedstock (2).

5. A conversion process according to any preceding claim, comprising treating the hydrocarbon effluent (57) in a separation section (58) to separate water (61) and a light gas purge (60) comprising hydrogen and C1-C2 hydrocarbon compounds, and producing an aromatics-enriched effluent (62) to feed the first hydrocarbon feedstock (2).

6. Conversion method according to claim 5, wherein the separation section (58) is adapted to: separate a recycle effluent (59) comprising at least one of the following compounds: C3-C4 hydrocarbon compounds, C5-C10 non-aromatic hydrocarbon compounds, benzene, toluene; and recycle the recycle effluent (59) to the inlet of the aromatization reaction section (56).

7. Conversion method according to any one of the preceding claims, in which the synthesis gas production unit (13; 14) comprises: a pyrolysis unit (13) comprising at least one reactor used under at least one of the following operating conditions: absolute pressure between 0.1 MPa and 0.5 Mpa and WH between 0.01 h' 1 and 10 a.m. 1 , preferably between 0.01 h' 1 and 5 a.m. 1 , and very preferably between 0.1 h' 1 and 3 a.m. 1, WH is the ratio of the volume flow rate of feed to the volume of catalyst used; temperature between 400°C and 1000°C, preferably between 400°C and 650°C, preferably between 450°C and 600°C and preferably between 450°C and 590°C; zeolitic catalyst comprising and preferably consisting of at least one zeolite chosen from ZSM-5, ferrierite, zeolite Beta, zeolite Y, mordenite, ZSM-23, ZSM-57, EU-1, ZSM-11 and preferably the catalyst is a catalyst comprising only ZSM-5; or an oxycombustion unit (14) comprising at least one reactor used in at least one of the following operating conditions: a reactor operating in a fluidized bed; temperature between 500°C and 1000°C; pressure between 0.1 MPa and 3 MPa, preferably between 0.1 MPa and 1 MPa;or a gasification unit comprising at least one gasification furnace used under at least one of the following operating conditions: temperature between 700°C and 1400°C; 8. Conversion method according to any one of the preceding claims, wherein the methanol synthesis reaction section (50) comprises at least one reactor used under at least one of the following operating conditions: temperature between 200°C and 450°C, preferably between 220°C and 400°C, and more preferably still between 250°C and 350°C; pressure between 1 MPa and 12 MPa, preferably between 2 MPa and 10 MPa, and more preferably between 5 MPa and 10 MPa; hydrogen to COx molar ratio in which COx represents CO and CO2, between 3 and 10, preferably between 3 and 7, very preferably between 3 and 5; space velocity of the gas at the reactor inlet between 0.2 g / g ca ta / h and 1 g / gca your / h.

9. Conversion method according to any one of the preceding claims, wherein the aromatization reaction section (56) comprises at least one reactor used under at least one of the following operating conditions: temperature between 250°C and 500°C, preferably between 300°C and 450°C, and more preferably still between 350°C and 420°C; pressure between 0.1 MPa and 1 MPa, preferably between 0.2 MPa and 0.8 MPa, and more preferably between 0.4 MPa and 0.5 MPa; space velocity of the gas at the inlet of the reactor between 0.2 g / g ca ta / h and 1 g / g ca your / h.

10. Device for converting a first hydrocarbon feedstock comprising aromatic compounds, comprising: a fractionation train (4-7) adapted to extract at least one cut comprising benzene (22), one cut comprising toluene (23) and one cut comprising xylenes and ethylbenzene (24) from the first hydrocarbon feedstock (2); a xylene separation unit (10) adapted to treat the cut comprising xylenes and ethylbenzene (24) and produce an extract (39) comprising paraxylene and a raffinate (40) comprising orthoxylene, metaxylene and ethylbenzene; an isomerization unit (11) adapted to treat the raffinate (40) and produce an isomerate (42) enriched in paraxylene sent to the fractionation train (4-7); a synthesis gas production unit (13; 14) adapted to treat a second hydrocarbon feedstock (30) and produce a synthesis gas (32) comprising at least CO and CO2;a methanol synthesis reaction section (50) adapted to convert CO and CO2 from synthesis gas (32) into methanol (51); an aromatization reaction section (56) adapted to convert at least in part the methanol (51) into aromatic compounds and produce a hydrocarbon effluent (57) comprising aromatic compounds, and feed the first hydrocarbon feedstock (2) at least in part with the hydrocarbon effluent (57).

11. Conversion device according to claim 10, comprising a purification section (52) adapted to treat the methanol (51) to separate from water (53) and produce purified methanol (55).

12. Conversion device according to claim 11, wherein the purification section (52) is adapted to separate a recycle gas (54) comprising unconverted CO and / or unconverted CO2, and recycle the recycle gas (54) to the inlet of the methanol synthesis reaction section (50).

13. Conversion device according to any one of claims 10 to 12, in which the synthesis gas production unit (13; 14) comprises a pyrolysis unit (13) adapted to produce at least one pyrolysis effluent (31) comprising hydrocarbon compounds of 6 to 10 carbon atoms at least partially feeding the first hydrocarbon feedstock (2).

14. Conversion device according to any one of claims 10 to 13, comprising a separation section (58) adapted to treat the hydrocarbon effluent (57) to separate water (61) and a light gas purge (60) comprising hydrogen and C1-C2 hydrocarbon compounds, and to produce an effluent enriched in aromatic compounds (62) to feed the first hydrocarbon feedstock (2).

15. Conversion device according to claim 14, wherein the separation section (58) is adapted to: separate a recycle effluent (59) comprising at least one of the following compounds: C3-C4 hydrocarbon compounds, C5-C10 non-aromatic hydrocarbon compounds, benzene, toluene, and recycle the recycle effluent (59) to the inlet of the aromatization reaction section (56).

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