Production of aromatics and ethanol by biomass conversion

Abstract

Disclosed are a process and a device for converting a hydrocarbon feedstock, in which a unit for producing ethanol by biochemical transformation (13) treats a hydrocarbon feedstock (30) to produce ethanol (31) and CO2 (32); and a methanol synthesis reaction section (50) treats the CO2 to produce methanol (51). Preferably the methanol is aromatized in an aromatization reaction section (56) and then sent to a fractionation train (4-7), a xylene separation unit (10) and an isomerization unit (11) to produce xylene.

Description

[0001] Production of aromatics and ethanol by biomass conversion

[0002] Technical field

[0003] The invention relates to the production of ethanol and aromatics for petrochemistry (benzene, toluene, xylenes, ie, BTX). More particularly, the subject matter of the invention relates to the production of ethanol and aromatics (e.g. paraxylene) from the conversion of hydrocarbon compounds (e.g. biomass) into ethanol and CO2, the CO2 being converted into aromatics. The invention also relates to the production of ethanol and methanol from the conversion of hydrocarbon compounds. The invention also relates to the production of aviation fuel comprising the conversion of methanol and / or ethanol and / or other effluents from the conversion of hydrocarbon compounds.

[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),

[0006] I (toluene) or 2 (xylenes) methyl groups, and in particular, within xylenes, paraxylene, having the highest market value.

[0007] Biochemical biomass conversion processes produce ethanol, but with the co-production of a large amount of CO2 from the fermentation of sugars resulting from the conversion by enzymatic hydrolysis of biomass. The amount of CO2 produced can be of the same order of magnitude as the amount of ethanol produced.

[0008] It is therefore advantageous to implement a solution allowing this CO2 to be recovered, particularly in the form of high added value aromatic compounds.

[0009] Prior art

[0010] The processes for producing alcohol, in particular to produce ethanol by fermentation, comprise, in a known manner, the following succession of steps: crushing of the biomass, possibly impregnation of the biomass, then pretreatment by steam explosion or cooking under acidic conditions, enzymatic hydrolysis to produce sugars or bio-sourced molecules and alcoholic fermentation to produce ethanol or other type of fermentation to produce bio-sourced molecules, the ethanol (or bio-sourced molecules) then being separated, for example, by distillation. CO2 is produced during the fermentation step. To date, aromatic complexes make it possible to produce benzene, possibly toluene, and xylenes (often paraxylene, sometimes orthoxylene).An aromatic complex generally has at least one catalytic unit exhibiting at least one of the following functions: the isomerization of 8-carbon aromatic compounds, 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 produces benzene and xylenes.

[0011] The aromatic loop allows the production of high-purity paraxylene by adsorption separation or by crystallization, an operation well known in the prior art. This “C8-aromatic loop” includes a step for 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 mixture constituents in the form of crystals.

[0012] 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.

[0013] 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 CO2 form, and in particular bio-sourced carbon, into high added-value compounds. One object of the present invention is to overcome these drawbacks.

[0014] Summary of the invention

[0015] 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 ethanol and aromatics for petrochemistry making it possible to convert (for example in full) carbon dioxide, i.e., CO2, produced by biochemical transformation of biomass, into aromatic compounds.

[0016] The invention is based on the conversion of CO2 into aromatic compounds which are introduced into the aromatic complex, and in particular on the arrangement of several units allowing the conversion of CO2 into aromatic compounds in two stages: in a methanol synthesis reactor then in a methanol aromatization reactor. The aromatic compounds resulting from the conversion of CO2 are treated within the aromatic loop.

[0017] Specifically, the subject matter of the present invention relates to a method and a device using and comprising a unit for converting CO2 into methanol followed by a unit for aromatizing 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.

[0018] According to a first aspect, the aforementioned objects, as well as other advantages, are obtained by a method for converting a hydrocarbon feedstock, comprising the following steps: treating a hydrocarbon feedstock, e.g. biomass, in an ethanol production unit by biochemical transformation to produce ethanol and CO2; and treating at least part of the CO2 in a methanol synthesis reaction section to produce methanol.

[0019] An advantage of the present invention is in particular to be able to produce methanol in a single step from CO2 gas, a by-product of the biochemical transformation of biomass.

[0020] According to one or more embodiments, the method comprises the following steps: at least partially treating the methanol in an aromatization reaction section to produce a hydrocarbon effluent comprising aromatic compounds;

[0021] According to one or more embodiments, the method comprises the following steps: fractionating at least in part the hydrocarbon effluent 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 a paraxylene-enriched isomerate; sending the paraxylene-enriched isomerate to the fractionation train. Another advantage of the present invention is in particular to be able to convert CO2, a by-product of the biochemical transformation of biomass, into aromatic compounds in only two steps.

[0022] Another advantage of the present invention is in particular to be able to convert CO2, a by-product of the biochemical transformation of biomass, into paraxylene.

[0023] According to one or more embodiments, the method comprises treating methanol in a purification section to separate water and produce purified methanol.

[0024] According to one or more embodiments, the purification section is adapted to separate a recycle gas comprising unconverted CO2, and recycle the recycle gas to the inlet of the methanol synthesis reaction section.

[0025] One of the advantages of the present invention is in particular to be able, through recycling, to convert all of the CO2.

[0026] According to one or more embodiments, the second hydrocarbon feedstock comprises biomass, preferably lignocellulosic, and the treatment of the second hydrocarbon feedstock in the ethanol production unit by biochemical transformation comprises the following elementary steps: grinding the biomass into particles; optionally washing and separating the particles; optionally impregnating the particles into impregnated lignocellulosic substrate; optionally solid / liquid separation of the impregnated lignocellulosic substrate; pretreatment by steam explosion or cooking under acidic conditions; enzymatic hydrolysis to produce sugars or bio-sourced molecules; and alcoholic fermentation to produce ethanol and CO2.

[0027] According to one or more embodiments, the method comprises providing a supply of hydrogen (H2) in the CO2 stream, for example by means of a make-up line arranged (directly) upstream of the methanol synthesis reaction section.

[0028] 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 fractionation train.

[0029] 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.

[0030] 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.

[0031] According to one or more embodiments, the biochemical transformation of the lignocellulosic biomass comprises at least one of the following steps: a) the lignocellulosic biomass is conditioned by at least one grinding step, in particular so as to obtain ground biomass particles having a size of at most 300 mm; b) said particles are washed with an aqueous solution of pH between 4 and 8.5, at a temperature between 10 and 95°C, at atmospheric pressure, and for a duration between 1 minute and 300 minutes; c) the aqueous solution is separated from the washed biomass particles to obtain, on the one hand, a lignocellulosic substrate having a dry matter content between 15 and 70% by weight, and, on the other hand, a spent aqueous washing solution; d) impregnating said lignocellulosic substrate with an acid liquor, so as to obtain an impregnated lignocellulosic substrate having a pH of between 0.1 and 3;e) a solid / liquid separation of the impregnated lignocellulosic substrate is carried out, in order to obtain, on the one hand, a second lignocellulosic substrate having a dry matter content of between 15% by weight and 70% by weight, and, on the other hand, a liquid effluent; f) said second impregnated lignocellulosic substrate resulting from step e) is pretreated by steam explosion, or by cooking, in particular for a period of between 1 minute and 120 minutes, so as to obtain a pretreated lignocellulosic substrate; g) an enzymatic hydrolysis of the pretreated lignocellulosic substrate is carried out by enzymes produced from microorganisms of the fungal type, so as to obtain a hydrolysate containing sugars; h) fermentation is carried out, by microorganisms of the bacterial or yeast type, of the hydrolyzate resulting from step g) to obtain a fermentation must containing at least one biosourced molecule such as a solvent and / or an alcohol;optionally, an enzyme production step and / or a production / propagation step of microorganisms used in step g) and / or h) are integrated into said process; optionally, at least a portion of the used aqueous washing solution separated in step c) is introduced into a step of said biomass treatment process which is subsequent to pretreatment step f), and / or into an enzyme production step and / or into a production / propagation step of the microorganisms used in step g) and / or h) when at least one of these enzyme production steps and / or production / propagation steps of microorganisms is integrated into said biomass treatment process.;

[0032] 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; hydrogen to 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.

[0033] 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.

[0034] According to a second aspect, the aforementioned objects, as well as other advantages, are obtained by a device for converting a hydrocarbon feedstock, 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 biochemical transformation ethanol production unit adapted to treat a second hydrocarbon feedstock, preferably biomass, preferably lignocellulosic, to produce ethanol and carbon dioxide (CO2); a methanol synthesis reaction section adapted to convert at least in part the CO2 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.;

[0035] 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.

[0036] According to one or more embodiments, the purification section is adapted to separate a recycle gas comprising unconverted CO2, and recycle the recycle gas to the inlet of the methanol synthesis reaction section.

[0037] According to one or more embodiments, the device comprises a make-up line for providing a supply of hydrogen in the CO2.

[0038] According to one or more embodiments, the unit for producing ethanol by biochemical transformation is adapted to treat the second hydrocarbon feedstock (30) comprising biomass, preferably lignocellulosic, and comprises the following elementary sections: section for grinding the biomass into particles; optional section for washing and separating the particles; optional section for impregnating the particles into impregnated lignocellulosic substrate; optional section for solid / liquid separation of the impregnated lignocellulosic substrate; pretreatment section by steam explosion or cooking under acidic conditions; enzymatic hydrolysis section for producing sugars or bio-sourced molecules; and alcoholic fermentation section for producing ethanol and CO2.

[0039] 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.

[0040] 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.

[0041] According to a third aspect, the aforementioned objects, as well as other advantages, are obtained by a process for producing aviation fuel comprising the conversion of methanol and / or hydrocarbon effluent and / or ethanol produced by the aforementioned processes. Embodiments 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.

[0042] List of figures

[0043] Figure 1 represents a schematic view of a method according to the present invention for increasing the production of aromatic compounds.

[0044] Description of the embodiments

[0045] 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 according to the present invention. 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.

[0046] 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.

[0047] The present invention can be defined as a method and a device comprising a sequence of unit operations making it possible to produce ethanol, paraxylene and benzene, in particular from biomass.

[0048] 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.

[0049] One of the features of the present invention can be summarized as the use of carbon dioxide (CO2), a by-product of a biomass biochemical transformation unit, to produce aromatic compounds. Thus, the biomass is upgraded to ethanol and aromatic compounds, without loss of carbon in the form of CO2.

[0050] Specifically, the combination of a CO2 to methanol conversion unit followed by a methanol aromatization unit and the introduction of aromatic compounds from the aromatization section into the aromatic complex makes it possible to produce benzene and paraxylene and thus to potentially fully recover the CO2 produced in the biomass biochemical transformation unit.

[0051] Referring to Figure 1, according to one or more embodiments, the method and device for converting aromatic compounds use and comprise: 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 aromatic 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 first hydrocarbon feed 2; the fractionation train 4-7 downstream of the optional aromatic 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 treat tetramethylbenzenes; an optional selective hydrogenolysis unit 9 adapted to treat 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 (e.g. directly) downstream of the selective hydrogenolysis unit 9, to produce a plurality of liquid effluent cuts; a xylene separation unit 10 (e.g. of the crystallization or simulated moving bed type using a molecular sieve and a desorbent such as toluene) for isolating paraxylene from 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, making it possible in particular to remove 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; a biochemical transformation unit 13 adapted to treat a second hydrocarbon feedstock 30, such as biomass, preferably lignocellulosic, and produce ethanol 31 and CO2 32; a methanol synthesis reaction section 50 to treat at least in part the CO2 32 coming from the biochemical transformation unit 13 and produce methanol 51; a first optional supplementary line to provide a supply of hydrogen 33 in the CO232;an optional purification section 52 for treating methanol, separating a water purge 53 and a recycle gas 54 comprising 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.;

[0052] It is understood that it is possible to stop the process according to the invention at the production of methanol 51 and / or hydrocarbon effluent 57, for example to use such compounds (as well as for example ethanol) for the production of aviation fuel. According to these embodiments, the fractionation train 4-7, the xylene separation unit 10 and one isomerization unit 11 are optional.

[0053] 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.

[0054] 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.

[0055] Advantageously, the first hydrocarbon feedstock 2 is supplied by the hydrocarbon effluent 57 or the effluent enriched in aromatic compounds 62.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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), 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 made up of the hydrocarbon effluent 57 (or effluent enriched in aromatic compounds 62). According to one or more embodiments, the first hydrocarbon feedstock 2 may comprise a mixture of bio-sourced aromatic and paraffinic compounds and a mixture of non-bio-sourced aromatic and paraffinic compounds (for example, originating from a catalytic reforming unit).

[0061] 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. 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 fraction 20 (essentially benzene and toluene) called extract from the aromatic 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 fraction 20 is a hydrocarbon feedstock (eg essentially) aromatic in C6-C7 (A6-A7).

[0062] 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).

[0063] 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.

[0064] 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+).

[0065] 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+).

[0066] 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+).

[0067] 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.

[0068] 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.

[0069] 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;

[0070] 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 hours -1 .

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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 VII IB with a content of between 0.1 and 0.3% by weight (reduced form), limits included, relative to the total weight of the catalyst.

[0078] 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.

[0079] The term WH corresponds to the volume of hourly hydrocarbon charge injected relative to the volume of catalyst charged.

[0080] According to one or more embodiments, the optional stabilization column 12 produces: at the bottom a stabilized cut comprising (e.g. essentially) benzene and toluene 44 optionally recycled to 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 (e.g. C5-) removed from the aromatic complex. According to one or more embodiments, the selective hydrogenolysis unit 9 is adapted to: treat mono-aromatics having between 9 and 10 carbon atoms 25; and produce a hydrogenolysis effluent enriched in methyl-substituted aromatic compounds 46.

[0081] 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 to reduce 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.

[0082] 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;

[0083] 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 ).

[0084] The term PPH corresponds to the weight of injected hourly hydrocarbon charge relative to the weight of loaded catalyst.

[0085] 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 VII IB IB I IB) is also possible. The catalyst is supported on a refractory oxide (e.g. alumina, silica), optionally treated with a base to neutralize it.

[0086] 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.

[0087] 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 biomass, preferably lignocellulosic biomass or one or more constituents of lignocellulosic biomass chosen from the group formed by cellulose, hemicellulose and lignin.

[0088] Lignocellulosic biomass can consist of wood, agricultural waste or plant waste. Other non-limiting examples of lignocellulosic biomass material are agricultural residues (straw, corn stalks, 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.

[0089] Lignocellulosic biomass can also come from by-products of the paper industry such as Kraft lignin, or black liquor from paper pulp production.

[0090] Lignocellulosic biomass is composed of three main constituents: cellulose (35 to 50%), hemicellulose (23 to 32%), which is a polysaccharide essentially made up of pentoses and hexoses, and lignin (15 to 25%), which is a macromolecule with a complex structure and high molecular weight, resulting from the copolymerization of phenylpropenoic alcohols. These different molecules are responsible for the intrinsic properties of the plant wall and are organized into a complex tangle.

[0091] Cellulose, the majority of this biomass, is thus the most abundant polymer on Earth and the one with the greatest potential for forming materials and biofuels. However, the potential of cellulose and its derivatives has not yet been fully exploited, mainly due to the difficulty of extracting cellulose. Indeed, this step is made difficult by the very structure of plants. The technological obstacles identified in the extraction and transformation of cellulose include its accessibility, its crystallinity, its degree of polymerization, the presence of hemicellulose and lignin. The principle of the process for converting lignocellulosic biomass by biochemical transformation in unit 13 uses an enzymatic hydrolysis step of the cellulose contained in plant materials to produce glucose.

[0092] The glucose obtained can then be fermented into different products such as alcohols (ethanol, 1,3-propanediol, 1-butanol, 1,4-butanediol, etc.) or acids (acetic acid, lactic acid, 3-hydroxypropionic acid, fumaric acid, succinic acid, etc.).

[0093] Cellulose and possibly hemicelluloses are the targets of enzymatic hydrolysis but are not directly accessible to enzymes. This is why these substrates must undergo pretreatment prior to the enzymatic hydrolysis step. Pretreatment aims to modify the physical and physicochemical properties of the lignocellulosic material, with a view to improving the accessibility of the cellulose trapped within the lignin and hemicellulose matrix. One of the most effective pretreatments is steam explosion, which allows almost complete hydrolysis of hemicellulose and a significant improvement in the accessibility and reactivity of cellulose to enzymes. This pretreatment may be preceded by other treatment(s) such as acid impregnation.Biomass impregnated with an aqueous solution, with or without acid, is continuously treated with steam in a reactor under pressure and temperature in order to mainly destructure the hemicellulose.

[0094] Pretreated biomass is composed of solids (primarily cellulose and lignin) and water-soluble sugars. In some process configurations, a fraction of the pretreated solids is sent to a soluble sugar extraction step to recover a sugary juice. For example, the paper "Lignocellulosic Biomass to Ethanol Process Design and Economies Utilizing Co-Current Dilute Acid Prehydrolysis and Enzymatic Hydrolysis for Corn Stove," Aden et al. NREL / TP-510-32438 teaches the separation of pretreated biomass into a solid fraction and a liquid fraction. This sugar-rich juice can then be used as a carbon source in enzyme production and yeast propagation units. The pretreated substrate depleted in soluble sugars can be directed to the enzymatic hydrolysis step along with the raw pomace exiting the pretreatment unit.

[0095] Enzymatic hydrolysis aims to convert the pretreated substrate into monomeric sugars. The enzyme cocktail used for this step is a mixture of cellulolytic and / or hemicellulolytic enzymes capable of breaking down cellulose into sugar solutions, including glucose. The enzymes in the enzyme cocktail contain three main types of enzymes depending on their activities: endoglucanases, exoglucanases, and cellobiases. The most commonly used microorganism for enzyme cocktail production is the fungus Trichoderma reesei. The enzyme cocktail production process begins with a propagation phase aimed at multiplying the filamentous fungus T. reesei. Once the fungus concentration is sufficient to produce a sufficiently concentrated enzyme cocktail, an enzyme cocktail production phase is induced by a change in the sugar substrate.At the end of this fermentation process, a must is obtained containing a mixture of enzymes and filamentous fungus T. reesei. This must can be used directly in enzymatic hydrolysis, or the enzymes can be separated from the fungus and then possibly concentrated.

[0096] The fermentation of sugars resulting from enzymatic hydrolysis into different products such as alcohols, solvents or acids requires the use of biocatalysts (bacteria or yeasts). Although the main target of the fermentation step is the conversion of sugars into bioproducts, and the conditions of the fermentation step are chosen to favor this metabolic pathway, the conduct of a fermentation step necessarily involves parallel reactions aimed at the development and maintenance of fermentative microorganisms. For example, Pasteur showed in the 19 ecentury that about 5% of sugars are converted into co-products, or used for cell maintenance and growth, in the case of the fermentation of glucose into ethanol by the yeast Saccharomyces cerevisiae.

[0097] The sweet juice from the pre-treated marc extraction step can be used partially or completely for the production of biocatalysts. This sugar-rich substrate is brought into contact with an inoculum of yeasts or bacteria in conditions favorable to their multiplication. The production of biocatalysts requires the supply of carbon and nitrogen compounds but also mineral elements and vitamins. The requirements vary depending on the type of biocatalyst considered. At the end of growth, the must obtained containing the yeasts or bacteria is directly used without separation in the fermentation step, or alternatively this must can be concentrated, for example by centrifugation.

[0098] This process for converting lignocellulosic biomass by biochemical transformation in unit 13 and producing ethanol 31 by fermentation therefore comprises, in a known manner, the following succession of steps: crushing of the biomass, possibly impregnation of the biomass, then pretreatment by steam explosion or cooking under acidic conditions, enzymatic hydrolysis to produce sugars or bio-sourced molecules and alcoholic fermentation to produce alcohols that can be used as biofuels such as ethanol or other type of fermentation to produce bio-sourced molecules, the ethanol (or biofuels or bio-sourced molecules) then being separated, for example, by distillation.

[0099] The fermentation stage is accompanied by the production of CO2 32.

[0100] In the unit 13 for converting lignocellulosic biomass by biochemical transformation, the second hydrocarbon feedstock 30 is in particular converted into ethanol 31 and CO2 32. The effluent comprising, preferably consisting of, CO2 32 is introduced into the unit 50 for converting CO2 into methanol. In the methanol synthesis reaction section 50, the CO2 gas 32, preferably enriched with a hydrogen supply 33, is converted at least partially into methanol and water. The reaction for synthesizing methanol from CO2 and CO is well known to those skilled in the art (see for example: US5631302, US4238403, EP 3 402 773, and Renewable Energy, 146 (2020), 1192-1203).

[0101] 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 / 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 t a / h and 1 g / g ca t a / h.

[0102] 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.

[0103] 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.

[0104] According to one or more embodiments, the CO2 stream 32 can be purified before being introduced into the methanol synthesis reaction section 50. The purification of the CO2 32 aims to remove sulfur compounds, nitrogen compounds, halogens, heavy metals and transition metals. The main gas purification technologies are: adsorption, absorption, catalytic reactions.

[0105] 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. In the optional purification section 52, the methanol 51 is treated to separate water 53 and a recycle gas 54 comprising 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 may 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 biochemical transformation unit 13 for biomass pretreatment operations.

[0106] 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 inlet of the reactor between 0.2 and 1 g / g ca t a / h.

[0107] According to one or more embodiments, the reactor of the aromatization reaction section 56 is adapted to operate in a fluid bed.

[0108] 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-5 / Al2C>3 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.

[0109] 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 feed separation unit 1 in a mixture with the first hydrocarbon feed 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 biochemical transformation unit 13 for biomass pretreatment operations; and a light gas purge 60 comprising hydrogen and C1-C2.

[0110] According to one or more embodiments, the recycle effluent 59 comprises benzene and / or toluene.

[0111] Advantageously, the combination of a methanol synthesis reaction section 50, followed by an aromatization section 56 makes it possible to produce aromatics from CO2, a by-product of the conversion unit of the second hydrocarbon feedstock 30 by biochemical transformation 13.

[0112] The method and device according to the invention thus make it possible, in particular from biomass, to produce ethanol and aromatic compounds.

[0113] According to one or more embodiments, the methanol 51 (or the purified methanol 55) and / or the hydrocarbon effluent (57) (or the effluent enriched in aromatic compounds 62) are partly removed from the process. Advantageously, the methanol and / or the ethanol (31) can serve as a base / precursor for producing aviation fuel (“jet fuel” according to English terminology). Advantageously, the process according to the invention makes it possible to obtain, in very few steps, aviation fuel from biomass.

[0114] 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.

[0115] Examples reference ed

[0116] Example 1 of a reference process for the biochemical transformation of a feedstock comprising lignocellulosic biomass is used.

[0117] In the reference example the units for converting CO2 to methanol 50 and methanol to aromatics 56 are absent.

[0118] For 100 t / h of poplar-type biomass, we obtain by biochemical transformation:

[0119] 21 t / h of ethanol;

[0120] 20.5 t / h of CO2. This represents a production roughly equivalent in mass of the desired product, ethanol, and a by-product, CO2.

[0121] Example 2 of the process according to the invention

[0122] Example 2 of the process according to the invention makes it possible to recover the CO2 by-product of the biochemical transformation stage of biomass into high added value aromatic compounds.

[0123] 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) from the purification section 52 to the inlet of the methanol synthesis reaction section 50. In this example 2, a hydrogen supply 33 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.

[0124] 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.

[0125] The CO2 32, produced by the biochemical transformation unit 13, is introduced into the methanol synthesis reaction section 50, with a hydrogen supply 33. 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 61 is purged, light gases 60 are purged, and the effluent enriched in aromatic compounds 62 is sent to the inlet of the aromatic complex.

[0126] Thanks to this process, the conversion of CO2, a by-product of the biochemical transformation of biomass, is complete.

[0127] The overall material balances of the reference processes and those according to the invention are compared in Table 1.

[0128] Table 1

[0129] Table 1 shows that the implementation according to the invention makes it possible to produce, in addition to ethanol, 5.246 t / h of paraxylene and 0.606 t / h of benzene, the CO2 by-product of the biochemical transformation of biomass being entirely converted into products of interest for petrochemicals.

Claims

Claims 1. A method for converting a hydrocarbon feedstock, comprising the following steps: treating a hydrocarbon feedstock (30) in an ethanol production unit by biochemical transformation (13) to produce ethanol (31) and CO2 (32); and treating at least part of the CO2 (32) in a methanol synthesis reaction section (50) to produce methanol (51).

2. A conversion process according to claim 1, comprising the following steps: at least partially treating the methanol (51) in an aromatization reaction section (56) to produce a hydrocarbon effluent (57) comprising aromatic compounds; at least partially fractionating the hydrocarbon effluent (57) 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).

3. A conversion process according to claim 1 or claim 2, comprising treating the methanol (51) in a purification section (52) to separate water (53) and produce purified methanol (55).

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

5. Conversion method according to any one of the preceding claims, in which the second hydrocarbon feedstock (30) comprises biomass, preferably lignocellulosic, and the treatment of the second hydrocarbon feedstock (30) in the ethanol production unit by biochemical transformation (13), comprises the following elementary steps: grinding the biomass into particles; pretreatment by steam explosion or cooking under acid conditions; enzymatic hydrolysis to produce sugars or bio-sourced molecules; and alcoholic fermentation to produce ethanol and CO2.

6. Conversion method according to any one of the preceding claims, comprising providing a supply of hydrogen (33) in the CO2 (32).

7. A conversion process according to any one of claims 2 to 6, 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 fractionation train (4-7).

8. Conversion method according to claim 7, 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).

9. 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 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 ta / h ; 10. Device for converting a hydrocarbon feedstock, 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 a 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 unit for producing ethanol by biochemical transformation (13) adapted to treat a second hydrocarbon feedstock (30) and produce ethanol (31) and CO2 (32); a methanol synthesis reaction section (50) adapted to convert at least in part the CO2 (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 water (53) and produce purified methanol (55).

12. Conversion device according to claim 10 or claim 11, in which the unit for producing ethanol by biochemical transformation (13) is adapted to treat the second hydrocarbon feedstock (30) comprising biomass, preferably lignocellulosic, and comprises the following elementary sections: section for grinding the biomass into particles; pretreatment section by steam explosion or cooking under acidic conditions; enzymatic hydrolysis section for producing sugars or bio-sourced molecules; and alcoholic fermentation section for producing ethanol and CO2.

13. Conversion device according to any one of claims 10 to 12, 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).

14. Conversion device according to claim 13, in which 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).

15. A process for producing aviation fuel comprising converting methanol and / or hydrocarbon effluent and / or ethanol produced by a conversion process according to any one of claims 1 to 9.

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