Process and apparatus for the production of para-tolualdehyde and monoethylene glycol from a biomass pyrolysis gas

Abstract

A process and apparatus for converting aromatic compounds, using / comprising: a fractionation train (4-6) and a transalkylation reaction unit (7) adapted to process a first hydrocarbon feed (2) and produce toluene (21); a pyrolysis unit (8) adapted to process a second hydrocarbon feed (9) and produce a pyrolysis effluent (10) feeding the first hydrocarbon feed (2), and a pyrolysis gas (11) comprising CO; an alkylation reaction unit (13) adapted to treat the pyrolysis gas with the toluene cut to produce para-tolualdehyde (14); an oxidative amine carbonylation reaction unit (30), a hydrogenation reaction unit (31), and a glycol separation unit (32) adapted to treat the pyrolysis gas to produce monoethylene glycol (40). Figure 1 to be published

Description

Title of the invention: Process and device for producing para-tolualdehyde and monoethylene glycol from a biomass pyrolysis gas Technical field

[0001] The invention relates to the production of para-tolualdehyde and monoethylene glycol (HOCH2CH2OH) for petrochemicals. More particularly, the subject of the invention relates to the association of an aromatic complex with a biomass pyrolysis device for the co-production of para-tolualdehyde and monoethylene glycol. Para-tolualdehyde and monoethylene glycol being two monomers allowing the synthesis of poly(ethylene terephthalate) (PET), the invention makes it possible to obtain 100% bio-sourced PET.

[0002] An aromatic complex is a known device for converting aromatic compounds fed by feedstocks predominantly composed of six to ten carbon atoms or more, referred to as C6 to C10+ feedstocks. Different sources of aromatic compounds can be introduced into an aromatic complex, the most widespread being derived from a catalytic reforming process of naphthas. Mixtures of aromatic compounds obtained by a lignocellulosic biomass conversion process can also, after purification treatment, be introduced into an aromatic complex. For example, the catalytic pyrolysis process of lignocellulosic biomass can be considered as a source of aromatics.

[0003] Within an aromatic complex, whatever the source of aromatics, benzene and aromatic alkyls (e.g. toluene, paraxylene, orthoxylene) are extracted and then converted into desired intermediates. In the context of the present invention, the aromatic complex considered produces predominantly para-tolualdehyde. The process according to the present invention differs significantly from the prior art, in which the aromatic complexes aim to produce benzene and paraxylene.

[0004] A pyrolysis device is a known device that can be fueled by biomass to produce a pyrolysis effluent comprising hydrocarbon compounds of 6 to 10 carbon atoms and a pyrolysis gas comprising carbon monoxide (CO). Prior art

[0005] To date, aromatic complexes make it possible to produce benzene, possibly toluene, and xylenes (often paraxylene, sometimes torthoxylene). An aromatic complex generally has at least one unit presenting at least one of the following functions: - the isomerization of aromatic compounds with 8 carbon atoms, known as A8 compounds, allowing the conversion of orthoxylene and metaxylene 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 produces benzene and xylenes.

[0006] The aromatic loop makes it possible to 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 removing 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 very generally a simulated moving bed (SMB) adsorption separation process to produce an extract and a raffinate, or a crystallization process in which a paraxylene fraction is isolated from the rest of the constituents of the mixture in the form of crystals.

[0007] The extract, which contains paraxylene, is then distilled to obtain high-purity paraxylene. The raffinate, rich in metaxylene and orthoxylene, is treated in an 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. This mixture is again sent to the “xylene column” with the fresh feed.

[0008] Various dedicated units can be added to this aromatic complex. However, the prior art does not mention any approach to integrating unit operations to simultaneously produce para-tolualdehyde and monoethylene glycol from biomass within the same complex. Summary of the invention

[0009] In the context described above, a first object of the present invention is to overcome the problems of the prior art and to provide a method and a device for producing para-tolualdehyde from aromatic compounds. More particularly, the present invention relates to an arrangement of unit operations, making it possible to convert biomass into aromatic compounds and CO / CO2, and in an aromatic complex to convert the aromatics resulting from the conversion of the biomass into para-tolualdehyde, using a reaction unit for alkylation of toluene by CO. The method and the device according to the invention also make it possible to convert part of the CO, a by-product of a pyrolysis unit, into monoethylene glycol. The present invention thus allows the production of biosourced polymer by the transformation of biomass into para-tolualdehyde and monoethylene glycol then into PET (poly(ethylene terephthalate)).

[0010] The invention is based in particular on the introduction of carbon monoxide, i.e., CO, into an aromatic complex, and on the arrangement of one or more reaction units making it possible to convert the CO and in particular to be able to produce para-tolualdehyde, monoethylene glycol and PET.

[0011] The invention relates to an aromatic complex associated with a biomass pyrolysis unit to which are added dedicated units for converting a portion of the CO-rich gaseous by-products from the pyrolysis unit into monoethylene glycol. The principle of this conversion is to use two reaction units: a reaction unit for the oxidative carbonylation of amine to form oxamides and / or oxamates, and a reaction unit for hydrogenating the oxamides and / or oxamates into monoethylene glycol. An advantage of this sequence is in particular to be able to use an amine which can be recycled, and is ultimately not a product of the process, but an intermediate for carrying out the conversion of a CO-rich gaseous effluent from the pyrolysis unit. The transformation of CO into monoethylene glycol can in particular be carried out as described in the work of M. Beller et al.(Nature Communications volume, 2016, 7, 12075) or in patent application WO 2021 / 198782 AL.

[0012] The invention is based on a pyrolysis unit whose hydrocarbon products of 6 to 10 carbon atoms are sent to an aromatic complex for the production of paraxylene, and whose pyrolysis gas comprising CO and H2 is converted into monoethylene glycol. Specifically, two reaction units allow the conversion of CO into monoethylene glycol: a first reaction unit for the oxidative carboxylation (with pure oxygen or air) of amine to form oxamides (and / or oxamates), and a second unit for the hydrogenation of oxamides (and / or oxamates) into monoethylene glycol. The amine used in the first stage is not destroyed by the process and can be recycled to the inlet of the first stage.

[0013] Specifically, the subject of the present invention can be summarized as an aromatic complex comprising distillation columns and two reaction units for converting aromatic compounds. In the first conversion reaction unit, benzene and xylenes are converted into toluene by transalkylation reaction. In the second conversion reaction unit, toluene is converted into para-tolualdehyde by alkylation reaction with CO. The aromatic compounds and CO are preferably derived from a catalytic pyrolysis process of biomass.

[0014] Furthermore, the para-tolualdehyde as well as the monoethylene glycol produced by the method and the device according to the invention can advantageously be biosourced products in the case where the aromatic compounds and the CO are biosourced, such as that come from a process of conversion of lignocellulosic biomass and in particular from a process of catalytic pyrolysis of biomass.

[0015] According to a first aspect, the aforementioned objects, as well as other advantages, are obtained by a process for converting a first hydrocarbon feedstock comprising aromatic compounds, comprising the following steps: - fractionating the first hydrocarbon feedstock in a fractionation train into at least: a cut comprising benzene, a cut comprising toluene and a cut comprising xylenes; - treating at least in part the cut comprising benzene and at least in part the cut comprising xylenes in a transalkylation reaction unit to produce a transalkylation effluent enriched in toluene sent to the fractionation train; - treating a second hydrocarbon feedstock in a pyrolysis unit to produce at least: a pyrolysis effluent feeding at least in part the first hydrocarbon feedstock, and a pyrolysis gas comprising CO, and optionally CO2 and / or H2; - treating at least in part the cut comprising toluene and in part the pyrolysis gas in an alkylation reaction unit to produce an effluent enriched in para-tolualdehyde; - partially treating pyrolysis gas with an amine in an amine oxidative carbonylation reaction unit to produce a carbonylation effluent comprising oxamides and / or oxamates; - treating at least in part the carbonylation effluent in a hydrogenation reaction unit to produce a hydrogenation effluent comprising monoethylene glycol; and - separate the hydrogenation effluent in a glycol separation unit to produce monoethylene glycol.

[0016] According to one or more embodiments, the method comprises at least partially processing monoethylene glycol and para-tolualdehyde in a synthesis unit to produce poly(ethylene terephthalate).

[0017] According to one or more embodiments, the method comprises extracting at least in part the H2 from the pyrolysis gas and / or the CO2 present in the pyrolysis gas in a CO2 and / or H2 separation unit arranged between the pyrolysis unit and the oxidative amine carbonylation reaction unit.

[0018] According to one or more embodiments, the pyrolysis unit comprises at least one reactor used under the following operating conditions: - presence of a catalyst, preferably a zeolitic catalyst, preferably a zeolitic catalyst comprising at least one zeolite chosen from ZSM-5, ferrierite, Beta zeolite, Y zeolite, mordenite, ZSM-23, ZSM-57, EU-1, ZSM-11, preferably a catalyst comprising only a ZSM-5 type zeolite; the zeolite used in the catalyst can advantageously be doped with a metal chosen from Iron, Gallium, Zinc and Lanthanum; - a temperature between 400°C and 1000°C, preferably between 400°C and 650°C, preferably between 450°C and 600°C and very preferably between 450°C and 590°C; - an absolute pressure between 0.1 MPa and 0.5 MPa; - a WH of between 0.01 h 1 and 10 h 1, preferably between 0.01 h 1 and 5 h 1, preferably between 0.1 h 1 and 3 h 1.

[0019] According to one or more embodiments, the amine oxidative carbonylation reaction unit comprises at least one oxidative carbonylation reactor used under the following operating conditions: - presence of amine and an oxidizing atmosphere, preferably provided by oxygen from the air or pure O2 (i.e., gas comprising essentially or only oxygen); - pressure between 2 MPa and 20 MPa, preferably between 5 MPa and 15 MPa; - temperature between 20°C and 200°C, preferably between 25°C and 100°C.

[0020] According to one or more embodiments, the amine is piperidine.

[0021] According to one or more embodiments, the hydrogenation reaction unit comprises at least one hydrogenation reactor used under the following operating conditions: - pressure between 2 MPa and 25 MPa, preferably between 5 MPa and 10 MPa, : - temperature between 20°C and 250°C, preferably between 100°C and 200°C.

[0022] According to one or more embodiments, the amine effluent is recycled to the inlet of the amine oxidative carbonylation reaction unit.

[0023] According to one or more embodiments, the alkylation reaction unit comprises at least one alkylation reactor used under at least one of the following operating conditions: - temperature between 20°C and 100°C; - pressure between 2 MPa and 15 MPa; - PPH between 0.5 h 1 and 50 h 1, PPH corresponding to the weight of hourly hydrocarbon charge injected relative to the weight of catalyst loaded; - presence of a superacid catalyst.

[0024] According to one or more embodiments, the transalkylation unit comprises at least one first transalkylation reactor used under at least one of the following operating conditions: - temperature between 200°C and 600°C; - pressure between 2 MPa and 10 MPa; - PPH between 0.5 h 1 and 5 h 1, PPH corresponding to the weight of hourly hydrocarbon charge injected relative to the weight of catalyst loaded; - presence of a catalyst comprising zeolite.

[0025] According to one or more embodiments, the pyrolysis unit is adapted to further produce a liquid fraction comprising aromatic compounds with 9 or more carbon atoms.

[0026] According to one or more embodiments, the method uses a carbon dioxide (CO2) and / or H2 separation unit, arranged between the pyrolysis unit and the amine oxidative carbonylation reaction unit, and adapted to extract at least part of the H2 from the pyrolysis gas and / or the CO2 present in the pyrolysis gas.

[0027] According to one or more embodiments, the alkylation reaction unit is adapted to further produce a gaseous effluent comprising pyrolysis gases not converted in said alkylation reaction unit.

[0028] According to one or more embodiments, at least a portion of the pyrolysis gas is recycled to the pyrolysis unit.

[0029] According to one or more embodiments, at least a portion of the gaseous effluent is recycled to the pyrolysis unit.

[0030] According to one or more embodiments, the fractionation train is adapted to separate aromatic compounds with 9 and 10 carbon atoms.

[0031] According to one or more embodiments, the first hydrocarbon feedstock comprises at least 50% by weight of compounds comprising from 6 to 10 carbon atoms.

[0032] According to one or more embodiments, the second hydrocarbon feedstock is a mixture of hydrocarbon compounds having an elemental oxygen content at least greater than 1%.

[0033] According to one or more embodiments, the first hydrocarbon feedstock and / or the second hydrocarbon feedstock is biosourced.

[0034] According to one or more embodiments, the second hydrocarbon feedstock comprises or consists of biomass.

[0035] According to one or more embodiments, the first hydrocarbon feedstock consists of the pyrolysis effluent.

[0036] According to one or more embodiments, the alkylation reaction unit is adapted to separate a cut of by-products comprising compounds with 9 carbon atoms or more (C9+) from the effluent enriched in para-tolualdehyde.

[0037] According to one or more embodiments, the glycol separation unit produces an amine effluent recycled to the inlet of the amine oxidative carbonylation reaction unit.

[0038] According to one or more embodiments, the conversion process uses an oxygen makeup line adapted to provide a supply of pure air or oxygen into the oxidative amine carbonylation reaction unit.

[0039] According to one or more embodiments, the conversion process uses an H2 make-up line adapted to provide an H2 supply to the hydrogenation reaction unit.

[0040] 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 fractionate the first hydrocarbon feed into at least: a cut comprising benzene, a cut comprising toluene and a cut comprising xylenes; - a transalkylation reaction unit adapted to treat at least in part the cut comprising benzene and at least in part the cut comprising xylenes and produce a transalkylation effluent enriched in toluene sent to the fractionation train; - a pyrolysis unit adapted to treat a second hydrocarbon feedstock and produce at least: a pyrolysis effluent feeding at least in part the first hydrocarbon feedstock, and a pyrolysis gas comprising CO, and optionally CO2 and / or H2; - an alkylation reaction unit adapted to treat at least in part the cut comprising toluene and in part the pyrolysis gas to produce an effluent enriched in para-tolualdehyde; - an amine oxidative carbonylation reaction unit adapted to partially treat pyrolysis gas with an amine, and produce a carbonylation effluent comprising oxamides and / or oxamates; - a hydrogenation reaction unit adapted to treat at least part of the carbonylation effluent and produce a hydrogenation effluent comprising monoethylene glycol; and - a glycol separation unit suitable for separating the hydrogenation effluent and producing monoethylene glycol.

[0041] According to one or more embodiments, the device comprises a synthesis unit adapted to treat at least in part the monoethylene glycol and the para-tolualdehyde to produce poly(ethylene terephthalate).

[0042] According to one or more embodiments, the conversion device comprises a charge separation unit adapted to separate the first hydrocarbon charge from the aromatic complex into: a cut (eg top cut) comprising hydrocarbon compounds with 7 carbon atoms or less, sent to a benzene column from the fractionation train; and a cut (eg bottom cut) comprising aromatics with 8 carbon atoms or more, sent directly to a xylene column of the fractionation train.

[0043] According to one or more embodiments, the charge separation unit is adapted to separate a toluene fraction sent directly to the benzene column or a toluene column of the fractionation train.

[0044] According to one or more embodiments, the device further comprises an aromatics extraction unit adapted to treat at least in part the first hydrocarbon feedstock, for example the overhead cut of the feedstock separation unit, to extract an effluent comprising aliphatic compounds with 6-7 carbon atoms and produce an aromatic cut sent to the benzene column.

[0045] Embodiments according to the first aspect and the second aspect as well as other characteristics and advantages of the methods and devices according to the aforementioned aspects will appear on reading the following description, given solely for illustrative and non-limiting purposes, and with reference to the following drawing. Figure

[0046] [Fig.l] represents a schematic view of a process according to the present invention allowing the production of PET from biomass. Description of the embodiments

[0047] 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 and device. However, it will be apparent to those skilled in the art that the method and device may be implemented without these specific details. In other cases, well-known features have not been described in detail to avoid unnecessarily complicating the description.

[0048] In the present description, 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.

[0049] The present invention can be defined as a process and a device comprising a sequence of unit operations making it possible to produce aromatic compounds such as para-tolualdehyde, and to produce monoethylene glycol.

[0050] The method and the device according to the invention are characterized in that they comprise take and use units known to those skilled in the art to produce benzene, toluene and xylenes, units which are usually found in aromatic complexes, and in that they comprise and use a reaction unit for alkylation of toluene by CO which produces para-tolualdehyde.

[0051] Furthermore, the method and the device according to the invention are characterized in that they comprise a reaction unit for transalkylation of benzene and xylenes to convert them into toluene.

[0052] Advantageously, the combination of the reaction unit for transalkylation of benzene and xylenes and a unit for alkylation of toluene by CO producing para-tolualdehyde and the complex fractionation train makes it possible to obtain only para-tolualdehyde and a purge of heavy aromatic compounds (in small quantities).

[0053] Furthermore, one of the features of the present invention consists of the use of CO, a by-product of a biomass pyrolysis unit to produce monoethylene glycol.

[0054] With reference to [Fig.l], according to one or more embodiments, the method / device for converting aromatic compounds uses / comprises: - an optional charge separation unit 1 for separating a first hydrocarbon charge 2 from the aromatic complex into a top cut 16 comprising hydrocarbon compounds with 7 carbon atoms or less (C7-) and a bottom cut 17 comprising aromatic compounds with 8 carbon atoms or more (A8+); - an optional aromatics extraction unit 3 between the charge separation unit 1 and a fractionation train 4-6 to separate the aliphatic compounds of benzene and toluene from the C7- cut of the complex feed; - the fractionation train 4-6 downstream of the optional aromatics extraction unit 3 making it possible to extract cuts comprising benzene 22, toluene 23 and xylenes 24 from the other aromatics; - a transalkylation reaction unit 7 converting benzene 22 and xylenes 24 into toluene; - a pyrolysis unit 8, preferably catalytic, for treating a second hydrocarbon feedstock 9, producing a pyrolysis effluent 10 at least partially feeding the first hydrocarbon feedstock 2 of the aromatic complex, a pyrolysis gas 11 comprising carbon monoxide (CO), and optionally carbon dioxide (CO2) and / or dihydrogen (H2), and optionally a liquid fraction 12 (by-products composed mainly of middle distillates which, after hydrotreatment and / or hydrocracking, can be recovered in the form of Kerosene (or Jet Fuel), diesel or marine fuel); - an alkylation reaction unit 13 for alkylating the toluene cut 23 with CO from the pyrolysis gas 11 and produce an effluent enriched in para-tolualdehyde 14 (compared to the toluene cut 23) and optionally a gaseous effluent 15 comprising unconverted pyrolysis gases; - an amine oxidative carbonylation reaction unit 30 for converting a portion of the pyrolysis gas 11 and producing a carbonylation effluent 36 comprising oxamides (and / or oxamates); - an optional CO2 and / or H2 separation unit (not shown) arranged between the pyrolysis unit 8 and the amine oxidative carbonylation reaction unit 30 to reduce the CO2 and / or H2 content of the pyrolysis gas 11; - an optional oxygen supply line 35 to provide a supply of pure air or oxygen to the pyrolysis gas 11; - a hydrogenation reaction unit 31 adapted to treat at least in part the carbonylation effluent 36 and produce a hydrogenation effluent 38 comprising monoethylene glycol; - a glycol separation unit 32 adapted to separate the hydrogenation effluent 38, produce monoethylene glycol 40 and recycle an amine effluent 39 to the inlet of the amine oxidative carbonylation reaction unit 30; - an optional H2 make-up line 37 to provide an H2 supply to the oxamide hydrogenation reaction unit 31; - an optional synthesis unit 33 adapted to treat at least in part the monoethylene glycol 40 and the para-tolualdehyde 39 to produce poly(ethylene terephthalate) 34.

[0055] Advantageously, the alkylation reaction unit 13 makes it possible to produce para-tolualdehyde from the toluene initially present in the first hydrocarbon feedstock 2 and formed by transalkylation of benzene with xylenes.

[0056] Advantageously, the amine oxidative carbonylation reaction unit (30), the hydrogenation reaction unit (31) and the glycol separation unit (32) make it possible to produce monoethylene glycol (40) from the pyrolysis gas 11.

[0057] Advantageously, the synthesis unit 33 makes it possible to produce PET 34 from monoethylene glycol 40 and para-tolualdehyde 39. Charge Separation Unit 1

[0058] With reference to [Fig.l], the feed separation unit 1 treats the first hydrocarbon feed 2 of the aromatic complex to separate a top cut 16 comprising (eg essentially) compounds with 7 carbon atoms or less (C7-) containing in particular benzene and toluene, and a bottom cut 17 comprising (eg essentially) aromatics with 8 carbon atoms or more (A8+) sent to the third aromatic compound distillation column 6, also called xylene column. According to one or more embodiments, ... charge 1 also separates a toluene fraction 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 toluene fraction 18. According to one or more embodiments, the toluene fraction 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.

[0059] 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.

[0060] 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 may comprise an effluent from the catalytic reforming of a naphtha or comprise a product from a cracking unit (eg steam, catalytic) or any other means of producing aromatic alkyls.

[0061] 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 pyrolysis effluent 10 originating from the pyrolysis unit 8 relative to the total weight of the first hydrocarbon feedstock 2.

[0062] According to one or more embodiments, the first hydrocarbon feedstock 2 is at least partially, or even entirely, biosourced. According to one or more embodiments, the first hydrocarbon feedstock 2 comprises a biosourced mixture of aromatic and paraffinic compounds and a non-biosourced mixture of aromatic and paraffinic compounds (for example, originating from a catalytic reforming unit). According to one or more embodiments, the first hydrocarbon feedstock 2 originates (essentially) from a process for converting lignocellulosic biomass. For example, an effluent produced by converting lignocellulosic biomass may 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.According to one or more embodiments, the first hydrocarbon feedstock 2 consists of the pyrolysis effluent 10 from the pyrolysis unit 8.

[0063] 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. The aromatic extraction unit

[0064] The overhead cut 16 from the feed separation unit 1 is sent to the optional aromatics extraction unit 3 adapted to extract an effluent comprising C6-C7 aliphatic species 19 which is exported as a co-product of the aromatic complex. The aromatic cut 20 (comprising essentially benzene and toluene), called extract from the aromatics extraction unit 3, is sent to the benzene column 4. According to one or more embodiments, the aromatic cut 20 is a hydrocarbon feed (eg essentially) aromatic in C6-C7 (A6-A7). The fractionation train

[0065] The fractionation train comprises the aromatic compound distillation columns 4, 5, and 6 making it possible to separate the following 4 cuts: - a cut comprising (eg essentially) benzene 22; - a cut comprising (eg essentially) toluene 23; - a cut comprising (eg essentially) xylenes 24; - a cut comprising (eg essentially) aromatic compounds with 9 and 10 carbon atoms 25.

[0066] The benzene column 4 is suitable for: treating the aromatic cut 20 which is a hydrocarbon feedstock (eg essentially) aromatic in C6-C10 (A6+); producing at the top the cut comprising benzene 22 which is sent at least in part to the inlet of the transalkylation reaction unit 7; and producing at the bottom an effluent (eg essentially) aromatic in C7-C10 26 (A7+).

[0067] The toluene column 5 is suitable for: treating the C7-C10 aromatic effluent 26 (A7+), the bottom product of the benzene column 4; producing at the top the cut comprising toluene 23 which is directed at least in part towards the alkylation reaction unit 13; and producing at the bottom an effluent (eg essentially) C8-C10 aromatic 27 (A8+).

[0068] 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 aromatic complex feed and optionally the bottom effluent from the toluene column 27; producing at the top the cut comprising mainly xylenes 24 which is directed at least in part towards the transalkylation reaction unit 7; and producing at the bottom an effluent (eg essentially) comprising C9-C10 aromatics 25 (A9+). The transalkylation reaction unit

[0069] In the transalkylation reaction unit 7, the fraction comprising benzene 22 from the top of the benzene column 4 is mixed with the cut comprising xylenes 24 from the top of the xylene column 6, and feeds at least one transalkylation reactor to produce toluene by transalkylation of aromatics lacking methyl groups (i.e., benzene), and in excess of methyl groups (i.e., xylenes).

[0070] The effluent enriched in toluene 21 (relative to the cut comprising benzene 22 and the cut comprising xylenes 24) from the transalkylation reaction unit 7 is sent to the inlet of the benzene column 4, optionally with the aromatic cut 20.

[0071] According to one or more embodiments, the transalkylation reaction unit 7 comprises at least one transalkylation reactor adapted to be used under at least one of the following operating conditions: - temperature between 200°C and 600°C, preferably between 350°C and 550°C, and even more preferably 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; - PPH between 0.5 h 1 and 5 h 1, preferably between 1 h 1 and 4 h 1, and more preferably between 2 h 1 and 3 h '.

[0072] The term PPH corresponds to the weight of injected hourly hydrocarbon charge relative to the weight of loaded catalyst.

[0073] According to one or more embodiments, the at least one transalkylation reactor is operated in the presence of a catalyst comprising zeolite, for example ZSM-5.

[0074] According to one or more embodiments, the at least one transalkylation reactor is of the fixed bed type. The pyrolysis unit

[0075] According to one or more embodiments, the second hydrocarbon feedstock 9 sent to the pyrolysis unit 8 is a mixture of hydrocarbon compounds having an elemental oxygen content at least 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 feedstock. According to one or more embodiments, the second hydrocarbon feedstock 9 comprises or consists of lignocellulosic biomass or one or more constituents of lignocellulosic biomass chosen from the group formed by cellulose, hemicellulose and lignin.

[0076] Lignocellulosic biomass may comprise 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, paper, recycled or not.

[0077] Lignocellulosic biomass can also come from by-products of the paper industry such as Kraft lignin, or black liquor from the manufacture of paper pulp.

[0078] The lignocellulosic biomass may advantageously undergo at least one pretreatment step (not shown) before its introduction into the pyrolysis unit 8. 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 to be pyrolyzed 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.

[0079] According to one or more embodiments, when the second hydrocarbon feedstock 9 is solid (e.g. biomass type feedstock), the second hydrocarbon feedstock 9 to be pyrolyzed is advantageously loaded into a drive compartment or pneumatic transport so as to be driven into a pyrolysis reactor 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. For example, a portion 42 of the pyrolysis gas 11 produced during the process may be recycled and used as a drive fluid. Said pyrolysis gas 11 is mainly a gaseous, non-condensable 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 the pyrolysis can be considerably reduced. The second hydrocarbon feedstock 9 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.

[0080] The drive fluid advantageously transports the second hydrocarbon feedstock 9 from the drive compartment into the pyrolysis reactor through a feed tube.

[0081] Typically, the feed tube is cooled to maintain the temperature of the second hydrocarbon feedstock 9 at a required level before it enters the pyrolysis reactor. 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 is not cooled.

[0082] According to one or more embodiments, the pyrolysis unit 8 comprises at least one pyrolysis reactor (e.g. fluidized bed) adapted to be used in at least one of the operating conditions listed below.

[0083] 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.

[0084] 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 h 1, preferably between 0.01 h 1 and 5 h 1, and very preferably between 0.1 h 1 and 3 h 1. The WH is the ratio of the volume flow rate of feedstock to the volume of catalyst used.

[0085] According to one or more embodiments, the pyrolysis step is catalytic and is carried out in the presence of a catalyst. Preferably, said step is carried out 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. 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.

[0086] According to one or more embodiments, the second hydrocarbon feedstock 9 first undergoes rapid pyrolysis by contacting the hot catalyst coming from a regenerator which in this step plays the role of thermal vector. The gases resulting from this pyrolysis will then react on the catalyst which this time plays its role of catalyst making it possible to catalyze the reactions producing the desired chemical intermediates.

[0087] In the pyrolysis unit 8, the second hydrocarbon feedstock 9 is in particular converted at least partially into a pyrolysis effluent 10 comprising hydrocarbon compounds whose carbon number ranges from 6 to 10 carbon atoms. The pyrolysis effluent 10 feeds the first hydrocarbon feedstock 2 of the aromatic complex. The pyrolysis unit 8 also produces a pyrolysis gas 11 comprising CO, CO2 and H2, and optionally a liquid fraction 12 (by-products).

[0088] The products obtained at the end of the pyrolysis step are advantageously recovered in the pyrolysis unit 8 in the form of a gaseous effluent comprising BTX (Benzene, Toluene, Xylenes).

[0089] Said gaseous effluent comprising the products obtained at the end of the pyrolysis step is then advantageously sent to a fractionation section of the pyrolysis unit 8 so as to separate at least the following cuts: - the pyrolysis effluent 10, liquid cut called BTX, comprising hydrocarbon compounds whose carbon number ranges from 6 to 10 carbon atoms, - pyrolysis gas 11, gaseous fraction of incondensables, comprising at least carbon monoxide (CO), carbon dioxide (CO2), and H2, - optionally liquid fraction 12 (also called middle distillate), liquid cut comprising mainly compounds having a number of carbon atoms greater than 9, i.e. at least 50% by weight of C9+ compounds; and - optionally water (not shown).

[0090] The pyrolysis gas 11 may also advantageously comprise light olefins comprising from 2 to 4 carbon atoms.

[0091] The coked catalyst as well as the second unconverted hydrocarbon feedstock usually called "char" are advantageously withdrawn from the pyrolysis reactor and preferably sent to a stripper so as to eliminate the potentially adsorbed hydrocarbons and thus avoid their combustion in the regenerator and this by contacting with at least one gas chosen from water vapor, an inert gas such as for example nitrogen, and a portion of the pyrolysis gas 11.

[0092] 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 combustion gas rich in CO2.

[0093] 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.

[0094] 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 aromatic relative to the total mass of the reaction products obtained, with a selectivity of at least 65% and preferably at least 70% in BTX.

[0095] According to one or more embodiments, the method thus comprises at least one pyrolysis step producing at least one BTX cut (pyrolysis effluent 10) and a gaseous fraction of incondensables (pyrolysis gas 11) comprising at least carbon monoxide and carbon dioxide.

[0096] According to one or more embodiments, the process also makes it possible to obtain, in addition to the BTX cut, a fraction of by-products (liquid fraction 12) heavier than the BTX cut, mainly aromatic called “C9+ cut” or which can advantageously be used in a process external to the process according to the invention.

[0097] According to one or more embodiments, at least a portion 42 of the pyrolysis gas 11 is recycled, preferably via a compressor (not shown in [Fig.l]), into the pyrolysis reactor. Advantageously, the recycled pyrolysis gas can serve as a fluid for driving the charge in the pyrolysis reactor. According to one or more embodiments, a purge of said recycled pyrolysis gas is carried out, either upstream or downstream of said compressor.

[0098] According to one or more embodiments, the pyrolysis effluent 10 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 10 may also contain molecules having more than 10 carbon atoms and / or molecules with 5 carbon atoms. The pyrolysis effluent 10 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. According to one or more embodiments, the pyrolysis effluent 10 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.According to one or more embodiments, the pyrolysis effluent 10 is a hydrocarbon fraction comprising molecules whose carbon number ranges from 6 to 8 carbon atoms.

[0099] According to one or more embodiments, the pyrolysis gas 11 produced by the pyrolysis unit 8 comprises a mixture containing predominantly (eg comprising at least 50% by weight) hydrogen, CO and CO2. According to one or more embodiments, the pyrolysis gas 11 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 (eg at least 50% by weight of CO). According to one or more embodiments, the pyrolysis gas 11 comprises at least 0.2% by weight of H2, preferably at least 0.5% by weight of H2, very preferably at least 0.8% by weight of H2. According to one or more embodiments, the pyrolysis gas 11 at the outlet of the pyrolysis unit 8 contains at least 20% by weight of CO2. According to one or more embodiments, the pyrolysis gas 11 at the outlet of the pyrolysis unit 8 contains approximately 30% (eg ± 10% by weight) of CO2.According to one or more embodiments, the pyrolysis gas 11 contains methane, ethylene and propylene (eg less than 10% by weight) as well as ethane, propane and water (eg less than 3% by weight).

[0100] According to one or more embodiments, the liquid fraction 12 comprises compounds with 9 carbon atoms or more, which may comprise, for example (eg at least 50% by weight) optionally alkylated di and tri aromatics. This fraction can be used directly as bunker fuel, for example, or undergo hydrotreatment and / or hydrocracking to improve its properties and be used as kerosene or diesel. The alkylation reaction unit

[0101] The alkylation reaction unit 13 is adapted to alkylate the toluene of the cut comprising toluene 23 from the toluene column 5, by the CO present in the pyrolysis gas 11, to produce an effluent enriched in para-tolualdehyde 14 and a gaseous effluent 15 comprising pyrolysis gases which have not been converted in the alkylation reaction unit 13.

[0102] According to one or more embodiments, the para-tolualdehyde-enriched effluent 14 comprises at least 80% by weight, preferably at least 90% by weight, and very preferably at least 95% by weight, of para-tolualdehyde.

[0103] According to one or more embodiments, the alkylation reaction unit 13 is adapted to separate a cut of by-products 28 comprising compounds with 9 carbon atoms or more (C9+) from the effluent enriched in para-tolualdehyde 14.

[0104] According to one or more embodiments, at least a portion 41 of the gaseous effluent 15 is recycled, preferably via a compressor (not shown in [Fig.l]), in the pyrolysis unit 8. The recycled gaseous effluent can then serve as a fluid for driving the second hydrocarbon feedstock 9 in the pyrolysis unit 8. According to one or more embodiments, a purge of said recycled gaseous effluent is carried out, either upstream or downstream of said compressor.

[0105] According to one or more embodiments, the alkylation reaction unit 13 comprises at least one alkylation reactor suitable for use under at least one of the following operating conditions: - temperature between 20°C and 100°C; - pressure between 2 MPa and 15 MPa, preferably between 5 MPa and 10 MPa; - PPH between 0.5 h 1 and 50 h 1.

[0106] According to one or more embodiments, the alkylation reaction of toluene by CO is carried out in the presence of an acid catalyst, such as a catalyst suitable for leading to an electrophilic attack of the toluene nucleus by CO. According to one or more embodiments, the acid catalyst is a superacid catalyst (i.e., a chemical compound more acidic than 100% pure sulfuric acid), such as a catalyst comprising trifluoromethanesulfonic acid, HF-SbF5, a sulfated zirconia, and / or an ionic liquid based on chloroaluminates comprising, for example, N-methyl imidazole. Advantageously, the alkylation reaction of toluene by CO is highly selective in the para isomer (>99%), for example at 25°C and at a partial pressure of CO equal to 7.5 MPa.

[0107] Thus the combination of a transalkylation reaction unit 7 and an alkylation reaction unit 13 makes it possible to convert most of the aromatic compounds resulting from pyrolysis of the biomass into para-tolualdehyde. The amine oxidative carbonylation unit

[0108] The amine oxidative carbonylation reaction unit 30 is adapted to treat a portion of the pyrolysis gas 11 with an amine and produce a carbonylation effluent 36 comprising oxamides (and / or oxamates).

[0109] According to one or more embodiments, an oxygen supply (pure oxygen or air) supplied by the oxygen make-up line 35 is added to the pyrolysis gas 11 so that the CO / O2 ratio of the partial pressures between the CO and the O2 is between 0.2 and 5, preferably between 0.25 and 4, very preferably between 0.33 and 3 at the inlet of the amine oxidative carbonylation reaction unit 30.

[0110] According to one or more embodiments, the amine oxidative carbonylation reaction unit 30 comprises at least one oxidative carbonylation reactor used under the following operating conditions: - presence of amine and an oxidizing atmosphere, preferably provided by oxygen from the air or pure O2 (i.e., gas comprising essentially or only oxygen); - pressure between 2 MPa and 20 MPa, preferably between 5 MPa and 15 MPa; - temperature between 20°C and 200°C, preferably between 25°C and 100°C.

[0111] According to one or more embodiments, the amine is a secondary amine. According to one or more embodiments, the amine is a heterocycle. According to one or more embodiments, the amine is piperidine.

[0112] According to one or more embodiments, the oxidative carbonylation catalyst comprises a metal chosen from the metals of groups 8, 9, and 10. Preferably the metal is palladium.

[0113] According to one or more embodiments, the oxidative carbonylation reactor comprises a homogeneous, heterogeneous or supported homogeneous oxidative carbonylation catalyst. According to one or more embodiments, the oxidative carbonylation catalyst comprises a phosphine, amine and / or carbene-based ligand. According to one or more embodiments, the metal of the carbonylation catalyst is stabilized by a phosphine or N-heterocyclic carbene (NHC) ligand. According to one or more embodiments, the metal is stabilized by a pincer-type ligand.

[0114] According to one or more embodiments, the oxidative carbonylation catalyst is a supported heterogeneous or homogeneous catalyst comprising a solid support of inorganic oxide type (eg SiO2, A12O3), polymer or carbon-based.

[0115] According to one or more embodiments, the oxidative carbonylation reactor comprises a promoter, in particular iodine, an iodide derivative, an ammonium iodide, or combinations thereof. By way of example, mention may be made of iodinated compounds such as Kl, Lil, Nal or Bu4NI.

[0116] According to one or more embodiments, the oxidative carbonylation is carried out under basic conditions. Any suitable base may be used. By way of example, mention may be made of inorganic bases such as K2CO3, NaOH, KOH or BuONa. The CO2 and / or H2 separation unit

[0117] According to one or more embodiments, an optional CO2 and / or H2 separation unit is arranged between the pyrolysis unit 8 and the amine oxidative carbonylation reaction unit 30, to extract at least in part the CO2 and / or H2 from the pyrolysis gas 11 at the outlet of the pyrolysis unit 8 so that the pyrolysis gas 11 at the inlet of the amine oxidative carbonylation reactor 30 comprises: - less than 10% by weight of CO2, preferably less than 5% by weight of CO2, very preferably less than 2% by weight of CO2; and / or - less than 5% by weight of H2, preferably less than 2% by weight of H2, very preferably less than 0.1% by weight of H2.

[0118] For example, at the outlet of the pyrolysis unit 8, the removal of CO2 and / or H2 can be carried out with an acid gas removal step, carried out for example using solvent absorption systems, or by means of membranes. The acid gases in generally consist of H2S, COS and CO2. Current methods for removing said acid gases generally involve countercurrent absorption with a regenerative solvent, in an absorbent column.

[0119] According to one or more embodiments, the optional CO2 and / or H2 separation unit is arranged upstream of the optional oxygen make-up line 35 providing the supply of pure air or oxygen. The hydrogenation reaction unit

[0120] The hydrogenation reaction unit 31 is adapted to treat at least in part the carbonylation effluent 36 and produce a hydrogenation effluent 38 comprising monoethylene glycol.

[0121] According to one or more embodiments, the oxamide hydrogenation reaction unit 31 comprises at least one hydrogenation reactor used under the following operating conditions: - pressure between 2 MPa and 25 MPa, preferably between 5 MPa and 10 MPa, - temperature between 20°C and 250°C, preferably between 100°C and 200°C.

[0122] According to one or more embodiments, the hydrogenation catalyst comprises a metal chosen from the metals of groups 8, 9, and 10, preferably the metal is chosen from ruthenium, nickel and iron.

[0123] According to one or more embodiments, the hydrogenation reactor comprises a homogeneous, heterogeneous or supported homogeneous hydrogenation catalyst. According to one or more embodiments, the hydrogenation catalyst is a homogeneous catalyst and comprises a phosphine and / or amine-based ligand. According to one or more embodiments, the metal of the hydrogenation catalyst is stabilized by a pincer-type ligand. According to one or more embodiments, the hydrogenation catalyst is a supported heterogeneous or homogeneous catalyst comprising a solid support of inorganic oxide type (e.g. SiO2, Al2O3), polymer or carbon-based.

[0124] According to one or more embodiments, the hydrogenation is carried out under basic conditions. Any suitable base may be used. For example, inorganic bases such as K2CO3, NaOH, KOH or BuONa may be mentioned. The glycol separation unit

[0125] The hydrogenation effluent 38 leaving the reaction unit 31 is introduced at least in part into a glycol separation unit 32 to separate the monoethylene glycol 40 and produce an amine effluent 39 which can be recycled to the inlet of the amine oxidative carbonylation reaction unit 30. The synthesis unit

[0126] According to one or more embodiments, the monoethylene glycol 40 and the para-tolualdehyde 14 are sent at least in part to a synthesis unit 33 to produce poly(ethylene terephthalate) 34. Advantageously, the invention makes it possible to obtain 100% bio-sourced PET. For example, in an oxidation section the para-tolualdehyde 14 is oxidized to terephthalic acid, and in an esterification section, the terephthalic acid is esterified with the monoethylene glycol 40 to form poly(ethylene terephthalate) 34. Examples

[0127] Example of a device according to the invention

[0128] The example device according to the invention makes it possible to produce poly(ethylene terephthalate) from biomass, using catalytic pyrolysis, units dedicated to the synthesis of monoethylene glycol from CO and an aromatic complex.

[0129] The example device according to the invention is similar to the device shown in [Fig.l].

[0130] The flow rates of the aromatic compounds of the pyrolysis effluent 10 from the unit of catalytic pyrolysis 8, as first hydrocarbon feed 2 at the inlet of the feed separation unit 1, are as follows: - benzene: 2.63 t / h; - toluene: 5.64 t / h; and - xylenes: 3.63 t / h.

[0131] A total of 11.9 t / h of aromatic compounds.

[0132] The pyrolysis unit 8 further produces a pyrolysis gas 11 containing 22.25 t / h of CO and 16 t / h of CO2. The pyrolysis gas 11 is used to convert all of the toluene into para-tolualdehyde by alkylation.

[0133] In addition, 3.454 t / h of CO is consumed by the alkylation reaction unit 13 to alkylate toluene into para-tolualdehyde. The remaining CO, i.e. 18.796 t / h, is used for the synthesis of monoethylene glycol 40.

[0134] According to the example of device according to the invention, the performances are listed in the following table 1.

[0135] [Tables 1] Loads t / h CO 22.25 Hydrogen 2.01 Benzene 2.63 Toluene 5.64 Xylenes 3.63 Products t / h Para-tolualdehyde 14.654 A9-A10 0.7 monoethylene glycol 20.81

[0136] Table 1 shows that the implementation according to the invention makes it possible to convert 94.1% of the aromatic compounds from a biomass pyrolysis unit 8 into para-tolualdehyde. All of the CO is converted into para-tolualdehyde and monoethylene glycol.

[0137] In addition, para-tolualdehyde and monoethylene glycol can be used for the synthesis of 23.44 t / h of poly(ethylene terephthalate) which is then 100% bio-sourced because it comes from biomass.

Claims

Claims

1. A method for converting a hydrocarbon feedstock, comprising the following steps: - fractionating a first hydrocarbon feedstock (2) comprising aromatic compounds in a fractionation train (4-6) into at least: a cut comprising benzene (22), a cut comprising toluene (23) and a cut comprising xylenes (24); - treating at least in part the cut comprising benzene (22) and at least in part the cut comprising xylenes (24) in a transalkylation reaction unit (7) to produce a transalkylation effluent (21) enriched in toluene sent to the fractionation train (4-6); - treating a second hydrocarbon feedstock (9) in a pyrolysis unit (8) to produce at least: a pyrolysis effluent (10) feeding at least in part the first hydrocarbon feedstock (2), and a pyrolysis gas (11) comprising CO;- treating at least in part the cut comprising toluene (23) and in part the pyrolysis gas (11) in an alkylation reaction unit (13) to produce an effluent enriched in para-tolualdehyde (14); - treating in part the pyrolysis gas (11) with an amine in an amine oxidative carbonylation reaction unit (30) to produce a carbonylation effluent (36) comprising oxamides and / or oxamates; - treating at least in part the carbonylation effluent (36) in a hydrogenation reaction unit (31) to produce a hydrogenation effluent (38) comprising monoethylene glycol; and - separating the hydrogenation effluent (38) in a glycol separation unit (32) to produce monoethylene glycol (40).;

2. A method according to claim 1, comprising at least partially processing the monoethylene glycol (40) and para-tolualdehyde (14) in a synthesis unit (33) to produce poly(ethylene terephthalate) (34).

3. A method according to claim 1 or claim 2, wherein: the alkylation reaction unit (13) comprises at least one alkylation reactor used under at least one of the following operating conditions: - temperature between 20°C and 100°C; - pressure between 2 MPa and 15 MPa; - PPH between 0.5 h 1 and 50 h1, PPH corresponding to the weight of injected hourly hydrocarbon feedstock relative to the weight of loaded catalyst; - presence of a superacid catalyst, and the transalkylation unit (7) comprises at least a first transalkylation reactor used in at least one of the following operating conditions: - temperature between 200°C and 600°C; - pressure between 2 MPa and 10 MPa; - PPH between 0.5 h 1 and 5 h1, PPH corresponding to the weight of injected hourly hydrocarbon feedstock relative to the weight of loaded catalyst; - presence of a catalyst comprising zeolite.

4. A method according to any one of the preceding claims, comprising the following step: - producing a gaseous effluent (15) comprising unconverted pyrolysis gases in said alkylation reaction unit (13).

5. A method according to claim 4, wherein at least a portion (41) of the gaseous effluent (15) is recycled to the pyrolysis unit (8).

6. A method according to any preceding claim, wherein a portion (42) of the pyrolysis gas (11) is recycled to the pyrolysis unit (8).

7. A method according to any one of the preceding claims, wherein the first hydrocarbon feedstock (2) comprises at least 50% by weight of compounds comprising from 6 to 10 carbon atoms.

8. A method according to any one of the preceding claims, wherein the second hydrocarbon feedstock (9) is a mixture of hydrocarbon compounds having an elemental oxygen content at least greater than 1%.

9. Method according to any one of the preceding claims, in which the first hydrocarbon feedstock (2) and / or the second hydrocarbon feedstock (9) is bio-sourced.

10. A method according to any preceding claim, comprising the following step: - separating 9 and 10 carbon aromatic compounds (25) in the fractionation train (4-6).

11. Device for converting a hydrocarbon feedstock, comprising: - a fractionation train (4-6) adapted to fractionate a first hydrocarbon feedstock (2) comprising aromatic compounds into at least: a cut comprising benzene (22), a cut comprising toluene (23) and a cut comprising xylenes (24); - a transalkylation reaction unit (7) adapted to treat at least in part the cut comprising benzene (22) and at least in part the cut comprising xylenes (24) and produce a transalkylation effluent (21) enriched in toluene sent to the fractionation train (4-6); - a pyrolysis unit (8) adapted to treat a second hydrocarbon feedstock (9) and produce at least: a pyrolysis effluent (10) feeding at least in part the first hydrocarbon feedstock (2), and a pyrolysis gas (11) comprising CO;- an alkylation reaction unit (13) adapted to treat at least in part the cut comprising toluene (23) and in part the pyrolysis gas (11) to produce an effluent enriched in para-tolualdehyde (14); - an amine oxidative carbonylation reaction unit (30) adapted to treat in part the pyrolysis gas (11) with an amine, and produce a carbonylation effluent (36) comprising oxamides and / or oxamates; - a hydrogenation reaction unit (31) adapted to treat at least in part the carbonylation effluent (36) and produce a hydrogenation effluent (38) comprising monoethylene glycol; and - a glycol separation unit (32) adapted to separate the hydrogenation effluent (38) and produce monoethylene glycol (40).;

12. Device according to claim 11, comprising a charge separation unit (1) adapted to separate the first hydrocarbon charge (2) into a hydrocarbon cut with 7 carbon atoms or less (16) sent to a benzene column (4) of the fractionation train (4-6), and an aromatic cut with 8 carbon atoms or more (17) sent to a xylene column (6) of the fractionation train (4-6).

13. Device according to claim 11 or claim 12, comprising an aromatic extraction unit (3) adapted to treat at least in part the first hydrocarbon feedstock (2) to extract an effluent comprising aliphatic compounds with 6-7 carbon atoms (19) and produce an aromatic cut (20) sent to the benzene column.

14. (4). Device according to any one of claims 11 to 13, comprising a synthesis unit (33) adapted to treat at least in part the monoethylene glycol (40) and the para-tolualdehyde (14) to produce poly(ethylene terephthalate) (34).

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