Conversion of a hydrocarbon feedstock derived from oxygen-rich biomass into aromatic isocyanates

Abstract

The invention relates to a device for converting an oxygen-rich hydrocarbon feedstock derived from biomass, comprising: - a pyrolysis unit; - a reaction section for WGS gas to water conversion; - a fractionation train suitable for extracting at least a cut comprising benzene, a cut comprising toluene, a cut comprising xylenes, and a cut comprising aromatic compounds containing 9 and 10 carbon atoms; - a nitration reaction section suitable for producing nitrated aromatic compounds from at least one cut extracted from said fractionation train; - a reduction reaction section; - an isocyanate synthesis reaction section.

Description

[0001] CONVERSION OF A HYDROCARBON FEED FROM OXYGEN-RICH BIOMASS INTO AROMATIC ISOCYANATES

[0002] Technical field

[0003] The invention relates to the conversion of oxygen-rich hydrocarbon compounds in the production of aromatics for petrochemicals. More particularly, the invention relates to the production of aromatic isocyanate-type chemical compounds, such as 4,4'-diphenylmethylene diisocyanate (MDI) or toluene diisocyanate (TDI), from a single hydrocarbon feedstock, preferably of bio-sourced origin.

[0004] State of the art

[0005] Generally, aromatic isocyanates are produced from:

[0006] - aromatic compounds from the recovery of petroleum, such as benzene or toluene; and

[0007] - phosgene from the conversion of a hydrocarbon feedstock (fossil, biomass or other).

[0008] Currently, aromatic isocyanate production processes use two types of feedstocks:

[0009] - a hydrocarbon feedstock that can be converted by gasification into hydrogen (H2) and carbon monoxide (CO). These two gases can be separated, then the carbon monoxide can be used to produce phosgene, then the hydrogen can be used as a reducing agent;

[0010] - an aromatic feedstock, such as benzene or toluene, which successively undergoes a nitrosation step, a reduction step and then a final transformation step into isocyanate using the phosgene produced from the hydrocarbon feedstock.

[0011] However, phosgene is a toxic and hazardous compound that requires careful handling. Finding alternatives to phosgene has proven beneficial for the environment and safety. The article by Wang et al. (Chinese Journal of Chemistry, 2017, 35, 821-835) lists existing alternatives to phosgene, including the use of carbon dioxide (CO2) or carbon monoxide (CO) for isocyanate synthesis.

[0012] Biomass pyrolysis processes, such as catalytic or thermal pyrolysis processes, can produce aromatic hydrocarbons, water and gas streams including CO and CO2 from a single lignocellulosic feedstock. A process based on biomass pyrolysis, whether catalytic or thermal, can therefore advantageously synthesize bio-sourced aromatic isocyanates from a single lignocellulosic biomass feedstock and minimize, or even avoid, the use of phosgene.

[0013] Objects of the invention

[0014] In the context described above, a first object of the present description is to overcome the problems of the prior art and to valorize carbon, and in particular biosourced carbon in the form of CO and / or CO2 in high added value compounds, and in particular in aromatic compounds, such as aromatic isocyanates.

[0015] Specifically, the present invention relates to a device and a method for maximizing the production of aromatic isocyanates from an oxygen-rich hydrocarbon feedstock derived from biomass (e.g. having an elemental oxygen content at least greater than 1% by weight, preferably at least 3% by weight, very preferably at least 5% by weight) by converting, at least in part, CO2 and optionally CO, by-products of biomass pyrolysis, into aromatic isocyanate compounds.

[0016] A first object according to the invention relates to a device for converting an oxygen-rich hydrocarbon feedstock from biomass comprising:

[0017] - a pyrolysis unit adapted to produce from a hydrocarbon feedstock derived from biomass at least one cut comprising aromatic compounds, a gaseous effluent comprising at least carbon monoxide, and water;

[0018] - a water gas conversion reaction section (WGS) adapted to produce a gas stream comprising hydrogen and carbon dioxide from carbon monoxide and water from the pyrolysis unit;

[0019] - a fractionation train adapted to extract at least one cut comprising benzene, one cut comprising toluene, one cut comprising xylenes, and one cut comprising aromatic compounds with 9 and 10 carbon atoms from said cut comprising aromatic compounds;

[0020] - a nitration reaction section adapted to produce nitro aromatic compounds from at least one cut extracted from said fractionation train;

[0021] - a reduction reaction section adapted to produce aromatic amines from nitro aromatic compounds and hydrogen from the WGS water gas conversion reaction unit;

[0022] - an isocyanate synthesis reaction section suitable for producing isocyanates from aromatic amines from the reduction reaction section, and carbon dioxide from the water gas conversion reaction section WGS, or carbon monoxide from the pyrolysis unit.

[0023] According to one or more embodiments according to the invention, said device further comprises a reaction section for separating (8) said gas stream (18) comprising hydrogen and carbon dioxide into at least one hydrogen-enriched stream (19) and at least one carbon dioxide-enriched stream (20).

[0024] According to one or more embodiments according to the invention, the isocyanate synthesis reaction section (6) is adapted to produce 4,4'-diphenylmethylene diisocyanate (MDI).

[0025] According to one or more embodiments according to the invention, the nitration reaction section (3) is adapted to produce nitrobenzene from the cut comprising benzene extracted from said fractionation train (2).

[0026] According to one or more embodiments according to the invention, said device further comprises a toluene disproportionation reaction section (11A) adapted to produce a benzene-enriched effluent (23) from the cut comprising toluene from said fractionation train (2).

[0027] According to one or more embodiments according to the invention, said device further comprises an aromatic amine condensation reaction section (5) for producing aromatic polyamines from aromatic amines from the reduction reaction section (4) and an aldehyde (21).

[0028] According to one or more embodiments according to the invention, the isocyanate synthesis reaction section (6) is adapted to produce toluene diisocyanate (TDI).

[0029] According to one or more embodiments according to the invention, the nitration reaction section (3) is adapted to produce dinitrotoluene from the cut comprising toluene extracted from said fractionation train (2).

[0030] According to one or more embodiments according to the invention, said device further comprises a transalkylation reaction section (11 B) adapted to produce a toluene-enriched effluent (25) from the cut comprising benzene and the cut comprising xylenes from said fractionation train (2). Another subject according to the invention relates to a method for converting an oxygen-rich hydrocarbon feedstock comprising the following steps: a) a biomass-derived hydrocarbon feedstock (11) is sent to a pyrolysis unit (1) to produce at least one cut comprising aromatic compounds (12), a gaseous effluent comprising at least carbon monoxide (9a), and water (10); b) the carbon monoxide (9a) and the water (10) obtained at the end of step a) are sent to a WGS water gas conversion reaction section (7) to produce a gaseous stream (18) comprising hydrogen and carbon dioxide;c) sending said cut comprising aromatic compounds (12) obtained at the end of step a) into a fractionation train (2) to extract at least one cut comprising benzene, a cut comprising toluene, a cut comprising xylenes, and a cut comprising aromatic compounds with 9 and 10 carbon atoms; d) sending at least one extracted cut obtained at the end of step c) into a nitration reaction section (3) to produce nitro aromatic compounds (14); e) sending said nitro aromatic compounds (14) obtained at the end of step d) and the hydrogen obtained at the end of step b) into a reduction reaction section (4) to produce aromatic amines (15);f) sending said aromatic amines (15) obtained at the end of step e), and the carbon dioxide obtained at the end of step b), or the carbon monoxide (14) obtained at the end of step a) into an isocyanate synthesis reaction section (6) to produce isocyanates (17).;

[0031] According to one or more embodiments according to the invention, said method further comprises a step g) in which said gaseous stream (18) comprising hydrogen and carbon dioxide obtained at the end of step b) is sent into a separation reaction section (8) to obtain at least one hydrogen-enriched stream (19) and at least one carbon dioxide-enriched stream (20).

[0032] According to one or more embodiments according to the invention, when 4,4'-diphenylmethylene diisocyanate (MDI) is produced in the isocyanate synthesis reaction section (6), said method further comprises a step h) in which the effluent comprising aromatic compounds (15) is sent to a condensation reaction section (5) of aromatic amines to obtain an effluent comprising aromatic polyamines (16). According to one or more embodiments according to the invention, said method further comprises a step i) in which at least one fraction comprising toluene (22) from the fractionation train (2) is sent to a toluene disproportionation reaction section (11 A) to obtain an effluent enriched in benzene and enriched in xylenes (23).

[0033] According to one or more embodiments according to the invention, when toluene diisocyanate (TDI) is produced in the isocyanate synthesis reaction section, said method further comprises a step j) in which a stream (24) comprising at least one fraction comprising benzene from the fractionation train (2) and at least one fraction of the xylenes from the fractionation train (2) is sent to a transalkylation reaction section (11 B) to obtain a toluene-enriched effluent (25).

[0034] List of figures

[0035] Figure 1 shows a schematic representation of a device of an embodiment according to the present invention for producing aromatic isocyanates from an oxygen-rich hydrocarbon feedstock derived from biomass. In this embodiment, the isocyanates are obtained from the aromatic amines from the reduction reaction section, and either carbon dioxide from the water gas conversion reaction section WGS, or carbon monoxide from the pyrolysis unit (1).

[0036] Figure 2 shows a schematic representation of a device according to an embodiment of the present invention for producing 4,4'-diphenylmethylene diisocyanate (MDI) from an oxygen-rich hydrocarbon feedstock derived from biomass.

[0037] Figure 3 shows a schematic representation of a device according to an embodiment of the present invention for producing toluene diisocyanate (TDI) from an oxygen-rich hydrocarbon feedstock derived from biomass.

[0038] Description of the embodiments

[0039] Embodiments of the device according to the first aspect and the method 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 device. However, it will be apparent to those skilled in the art that the device can be implemented without these specific details. In other cases, well-known features have not been described in detail to avoid unnecessarily complicating the description.

[0040] Definitions

[0041] 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 90% by weight, preferably at least 95% by weight, very preferably at least 99% by weight, of compounds A.

[0042] A water gas shift unit (WGS) is a unit that converts CO at least partially into CO2 and thus produces a gas enriched in CO2.

[0043] 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 VIII (or VI 11 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. detailed

[0044] The present invention can be defined as a device and a method comprising a sequence of unit operations making it possible to produce aromatic isocyanates from oxygen-rich hydrocarbon compounds such as biomass.

[0045] One of the features of the present invention can be summarized in the use at least in part of the CO2 produced in a WGS unit from the CO and water from the biomass pyrolysis unit, and / or at least in part of the CO from the catalytic pyrolysis unit, as a reactant for the synthesis of aromatic isocyanates, such as 4,4'-diphenylmethylene diisocyanate (MDI) or toluene diisocyanate (TDI).

[0046] With reference to figure 1, according to one or more embodiments, the device for converting aromatic compounds comprises: - a pyrolysis unit 1 adapted to produce from a hydrocarbon feedstock originating from the biomass 11 at least one cut comprising aromatic compounds 12, a gaseous effluent comprising at least carbon monoxide 9a, and water 10;

[0047] - a water gas conversion reaction section WGS 7 adapted to produce a gas stream 18 comprising hydrogen and carbon dioxide from carbon monoxide 9a and water 10 from the pyrolysis unit 1;

[0048] - a fractionation train 2 adapted to extract at least one cut comprising benzene, one cut comprising toluene, one cut comprising xylenes, and one cut comprising aromatic compounds with 9 and 10 carbon atoms from said cut comprising aromatic compounds 12;

[0049] - a nitration reaction section 3 adapted to produce nitro aromatic compounds 14 from at least one cut extracted from said fractionation train 2;

[0050] - a reduction reaction section 4 adapted to produce aromatic amines 15 from nitro aromatic compounds 14 and hydrogen from the water gas conversion reaction unit WGS 7;

[0051] - an isocyanate synthesis reaction section 6 adapted to produce isocyanates 17 from aromatic amines 15 from the reduction reaction section 4, and carbon dioxide from the water gas conversion reaction section WGS 7, or carbon monoxide 9b from the pyrolysis unit 1.

[0052] With reference to Figure 1, the pyrolysis unit 1 makes it possible to produce, from a hydrocarbon feedstock derived from biomass, the aromatic hydrocarbons and gases necessary for the production of aromatic isocyanates.

[0053] According to one or more embodiments, the hydrocarbon feedstock sent to the pyrolysis unit 1 is a mixture of hydrocarbon compounds having an elemental oxygen content at least greater than 1% by weight, preferably 3% by weight, very preferably 5% by weight relative to the total weight of said feedstock. According to one or more embodiments, the hydrocarbon feedstock comprises or consists of lignocellulosic biomass or one or more constituents of lignocellulosic biomass chosen from the group formed by cellulose, hemicellulose and lignin.

[0054] Lignocellulosic biomass may include wood, agricultural waste, or plant waste. Other non-limiting examples of lignocellulosic biomass material are agricultural residues (straw, corn stalk, etc.), forestry residues (first thinning products), forestry products, dedicated crops (short rotation coppice), residues from the agri-food industry, household organic waste, waste from wood processing facilities, used construction wood, and paper, whether recycled or not.

[0055] Lignocellulosic biomass can also come from by-products of the paper industry such as Kraft lignin, or black liquor from paper pulp production.

[0056] According to one or more embodiments, the pyrolysis step (step a) of the process according to the invention) is carried out at a temperature between 400°C and 1000°C, preferably between 400 and 650°C, preferably between 450°C and 600°C and preferably between 450°C and 590°C.

[0057] The pyrolysis step is also advantageously carried out at an absolute pressure of between 0.1 MPa and 0.5 MPa.

[0058] In the pyrolysis unit, the hydrocarbon feedstock is in particular converted at least partially into a pyrolysis effluent comprising hydrocarbon compounds whose carbon number ranges from 6 to 10 carbon atoms. The pyrolysis unit also produces a pyrolysis gas comprising CO, CO2 and H, and a liquid fraction of by-products.

[0059] The products obtained at the end of the pyrolysis step are advantageously recovered in the pyrolysis unit in the form of a gaseous effluent comprising BTX.

[0060] According to one or more embodiments, the method thus comprises at least one pyrolysis step producing at least one BTX cut (pyrolysis effluent) and a gaseous fraction of incondensables (pyrolysis gas) comprising at least carbon monoxide and carbon dioxide.

[0061] With reference to Figure 1, 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 so as to separate at least the following cuts:

[0062] - a gaseous fraction of incondensables 9a and / or 9b, comprising at least carbon monoxide (CO), and carbon dioxide (CO2);

[0063] - a liquid fraction 12 called BTX, comprising hydrocarbon compounds whose carbon number ranges from 6 to 10 carbon atoms; - a liquid fraction (not shown in Figure 1) comprising mainly compounds having a number of carbon atoms greater than 9, i.e. at least 50% by weight of C9+ compounds; and

[0064] - water 10.

[0065] With reference to Figure 1, the device according to the invention comprises a Water Gas Shift 7 (WGS) reaction section allowing the production of a gas flow 18 comprising at least in part H2 and CO2 from H2O 10 and CO 9a from the pyrolysis unit 1.

[0066] In the WGS reaction section 7, some or all of the CO and H2O produced in the pyrolysis unit 1 feeds at least one WGS reaction reactor to produce a gas stream 18 depleted in CO, depleted in H2O, enriched in CO2 and enriched in H2 (step b) of the process according to the invention). This gas stream 18 enriched in CO2 and H2 can be sent to the CO2 / H2 separation section 8 to separate the CO2 and H2.

[0067] The WGS reaction is well known to those skilled in the art (see for example Journal of Catalysis, volume 229, 2005, pages 265-275; and Renewable and Sustainable Energy Reviews, volume 93, 2018, pages 549-565).

[0068] According to one or more embodiments, the reaction section of WGS 7 comprises at least one reactor used under at least one of the following operating conditions:

[0069] - temperature between 250°C and 500°C, preferably between 300°C and 450°C, and even more preferably between 310°C and 425°C;

[0070] - pressure between 0.1 and 5 MPa, preferably between 0.2 and 4 MPa, and more preferably between 0.5 MPa and 3 MPa;

[0071] - a molar ratio H2O / CO between 1 and 4, preferably between 1.5 and 2.5, very preferably between 1.8 and 2.2, such as 2 (± 0.1);

[0072] - a space velocity of the gas at the reactor inlet between 1000 and 30000 mL / gcata / h.

[0073] According to one or more embodiments, the reactor of the WGS reaction section is adapted to operate in a fluidized bed or fixed bed.

[0074] According to one or more embodiments, the WGS reaction is carried out in the presence of a catalyst, such as a transition metal catalyst. For example, the catalyst may comprise iron and may optionally be promoted with chromium or copper. According to one or more embodiments, the catalyst comprises at least 50% by weight of Fe2Os, preferably at least 65% by weight of Fe2Os relative to the total weight of the catalyst. According to one or more embodiments, the catalyst further comprises between 2 and 20% by weight of O2O3 and / or CuO, preferably between 5 and 15% by weight of C^Ch or CuO relative to the total weight of the catalyst. According to one or more embodiments, the catalyst further comprises between 0.01 and 1% by weight of MgO, preferably between 0.1 and 0.5% by weight of MgO relative to the total weight of the catalyst.

[0075] According to one or more embodiments, the WGS reaction section is adapted to produce a WGS gas comprising at least 50% by weight of CO2 in the mixture of CO, CO2 and H2, preferably at least 75% by weight of CO2, very preferably at least 80% by weight of CO2.

[0076] According to one or more embodiments, the gas stream from the pyrolysis unit 1 can be purified before being introduced into the WGS reaction section 7. The purification aims to at least partially eliminate sulfur compounds, nitrogen compounds, halogens, heavy metals, transition metals and unsaturated hydrocarbons of two or more carbons. It can also make it possible to adapt the H2O and CO composition before entering the WGS reaction section or even to deplete the gas in CO2. The main technologies for purifying synthesis gases are: adsorption, absorption, catalytic reactions. In addition to gas purification, elimination of fine particles present in the fumes may be necessary (technologies: filtration, electrostatic precipitation, cyclones).

[0077] With reference to Figure 1, the device according to the invention may further comprise a CO2 / H2 separation section 8 making it possible to separate the CO2 and H2 from the other gases produced in the WGS reaction section 7.

[0078] In CO2 / H2 separation section 8, part or all of the gas stream 18 from the WGS reaction section 7 is treated (optional step g of the process according to the invention). This step makes it possible to generate at least one CO2-enriched stream 20 and at least one H2-enriched stream 19, and optionally a gas stream comprising the remainder of the gases produced (not shown in the figure).

[0079] There are several separation processes known to those skilled in the art, such as pressure swing adsorption (PSA), which separates H2 and CO2 from a gas. The adsorbents used in PSAs are generally highly porous materials with a large specific surface area. Silica gel, activated carbon, activated alumina, and zeolites are commonly used and can be used in multiple consecutive beds. An energy-efficient sequence of the WGS reaction section 7 and the CO2 / H2 separation section 8 has been described in patent application US 2021 / 0170322 A. Patent applications US 2018 / 0036674 A1 and US 2013 / 0011323 A1 describe examples of high-temperature gas separation (H2 and CO2) dedicated to the treatment of gases at the outlet of a WGS.

[0080] With reference to Figure 1, the device and the method according to the invention (step c) of the method according to the invention) comprise an aromatics fractionation train 2 making it possible to physically separate the aromatic compounds from the pyrolysis unit 1 and to obtain at least one effluent comprising aromatic compounds 13.

[0081] According to one or more embodiments, the fractionation train comprises several aromatic compound distillation columns making it possible to separate the following 4 cuts:

[0082] - a cut comprising (eg essentially) benzene;

[0083] - a cut comprising (eg essentially) toluene;

[0084] - a cut comprising (eg essentially) xylenes;

[0085] - a cut comprising (eg essentially) aromatic compounds with 9 and 10 carbon atoms.

[0086] In one embodiment according to the invention, when the device and the method according to the invention relate to the production of 4,4'-diphenylmethylene diisocyanate (MDI), the fractionation train 2 is used to obtain an effluent 13 comprising benzene.

[0087] In one embodiment according to the invention, when the device and the method according to the invention relate to the production of toluene diisocyanate (TDI), the fractionation train 2 is used to obtain an effluent 13 comprising toluene.

[0088] The benzene distillation column is suitable for treating the aromatic cut which is a hydrocarbon feedstock (eg essentially) aromatic in C6-C10 (A6+), producing at the top the cut comprising benzene which can optionally be sent to the inlet of a transalkylation reaction section 11B (see figure 3), and producing at the bottom an effluent (eg essentially) aromatic in C7-C10 (A7+).

[0089] The toluene distillation column is suitable for treating the C7-C10 aromatic effluent (A7+), the bottom product of the benzene column, producing at the top the cut comprising toluene which can optionally be directed towards a toluene disproportionation section 11 A (see figure 2), and producing at the bottom an effluent (eg essentially) C8-C10 aromatic (A8+).

[0090] The xylene distillation column is suitable for treating the aromatic cut with 8 carbon atoms or more (A8+) of the aromatic complex feed and optionally the bottom effluent from the toluene column, producing at the top the cut comprising mainly xylenes which can optionally be directed to a transalkylation reaction section 11B (see figure 3), and producing at the bottom an effluent (eg essentially) comprising C9-C10 aromatics (A9+).

[0091] Referring to Figure 1, the device and the method according to the invention (step d) of the method according to the invention) further comprise a nitration reaction section 3 allowing the production of an effluent comprising nitro aromatic compounds 14 from the effluent comprising aromatic compounds 13 from the fractionation train 2.

[0092] The nitration step is generally carried out in the liquid phase from nitric acid alone or in a mixture with other strong acids or catalysts and at least one aromatic compound. There are also gas routes from NO2 in particular, but these routes are less developed industrially. In the nitration reaction section 3, the effluent comprising the aromatic compounds 13, such as benzene (figure 2) or toluene (figure 3) from the top of the benzene column or from the top of the toluene column of the fractionation train 2 feeds at least one nitration reactor to produce an effluent comprising mono- or dinitrated nitro aromatic compounds 14. This reaction section can also be supplemented by a purification system to enrich the final effluent in mono- or dinitrated aromatic compound depending on the target.Preferably, the nitration reaction section 3 is used to produce an effluent of nitro aromatic compounds 14 which can be rich in nitrobenzene (depending on the embodiment as illustrated in FIG. 2) or in dinitrotoluene (depending on the embodiment as illustrated in FIG. 3).

[0093] Referring to Figure 1, the device and the method according to the invention (step e) of the method according to the invention) further comprise a reduction reaction section 4 for producing an effluent comprising aromatic amines 15, such as aniline or diaminotoluene, from the effluent comprising the nitro aromatic compounds 14 obtained at the end of the nitration reaction section 3 and from the hydrogen obtained at the end of the Water Gas Shift 7 (WGS) reaction section, optionally from the enriched hydrogen 19 obtained at the end of the CO2 / H28 separation section. The reduction of the nitro aromatic compounds to aromatic amines is an industrial step well known to those skilled in the art. In the reduction reaction section 4, the nitro aromatic compounds are reduced to the corresponding aromatic amines in the presence of hydrogen and a metal catalyst.The reduction of nitro aromatics can be done in the gas phase or in the liquid phase.

[0094] When the process is carried out in the gas phase, it is possible to use fixed bed or fluidized bed reactors. Palladium or copper, in combination with other metals (lead, vanadium, chromium, etc.) on activated carbon or oxide supports are generally used. The average hydrogen / aromatic nitrate ratio is approximately 10 / 1. This step is generally carried out at a temperature between 250°C and 350°C and at a pressure between 0.1 MPa and 1 MPa.

[0095] When the process is carried out in the liquid phase, catalysts based on nickel, platinum and palladium are preferred. In this embodiment, this step is generally carried out at a temperature between 90°C and 260°C, preferably between 90°C and 200°C, and at a pressure between 0.1 MPa and 4 MPa, preferably between 0.1 MPa and 0.6 MPa. More generally, this step is carried out at a temperature between 90°C and 200°C and at a pressure between 0.1 MPa and 0.6 MPa with slurry or fluidized bed reactor technologies.

[0096] The reduction reaction section can also be completed by a purification system to enrich the final effluent in a specific aromatic amine (dehydration column, distillation, gravimetric separator).

[0097] Preferably, the reduction reaction section 4 serves to produce an effluent 15 rich in aniline or toluenediamine (TDA) from benzene or toluene respectively and in the presence of H2.

[0098] Referring to Figure 1, the device and the method according to the invention (step f) of the method according to the invention) further comprise an isocyanate synthesis reaction section 6 allowing the production of an effluent comprising aromatic isocyanates 17 from the effluent comprising aromatic amines 15.

[0099] In one embodiment according to the invention, the effluent comprising the aromatic amines 15 is brought into contact with the CO2 obtained at the end of the WGS reaction section 7, optionally at the end of the CO2 / H28 separation section, and in the presence of an alcohol to form, in a first step, water and N-substituted aromatic carbamates. The N-substituted aromatic carbamates can then be isolated by distillation or by other purification methods. Finally, these compounds undergo thermal cracking to form aromatic isocyanates and re-release the alcohol which can be isolated and recycled.

[0100] In another embodiment according to the invention, the effluent comprising the aromatic amines 15 is brought into contact with carbon monoxide (via line 9b) from the pyrolysis unit 1 in the presence of a catalyst, an alcohol and C>2 to form, in a first step, water and N-substituted aromatic carbamates. The N-substituted aromatic carbamates can then be isolated by distillation or by other purification methods. Finally, these compounds undergo thermal cracking to form aromatic isocyanates and re-release the alcohol which can be isolated and recycled.

[0101] In another embodiment according to the invention, the carbon monoxide (via line 9b) from the pyrolysis unit is first brought into contact with a dichlorine feedstock to produce phosgene, then the phosgene is brought into contact with the aromatic amines 15. The phosgene synthesis step is generally carried out in the gas phase in the presence of a catalyst, generally an activated carbon, at a temperature between 50°C and 150°C. In this embodiment, the isocyanate synthesis reaction section 6 comprises a phosgene synthesis unit located upstream of the isocyanate synthesis unit.

[0102] Figure 2 illustrates a schematic representation of a device and method according to one embodiment of the present invention for producing 4,4'-diphenylmethylene diisocyanate (MDI) from an oxygen-rich hydrocarbon feedstock derived from biomass.

[0103] In this embodiment according to the invention, the device and the method according to the invention (optional step h) of the method according to the invention) further comprises a condensation reaction section 5 of the aromatic amines allowing the production of an effluent comprising aromatic polyamines 16 from the effluent comprising aromatic compounds 15 from the reduction reaction section 4. In the condensation reaction section 5, the effluent comprising aromatic compounds 15 in liquid phase is brought into contact with an aldehyde 21 and a strong acid or a solid catalyst to obtain an effluent comprising aromatic polyamines 16. This step is generally carried out at a temperature between 90°C and 110°C and at a pressure between 0.3 and 0.4 MPa.The condensation reaction section 5 can also be supplemented by a purification system to enrich the final effluent in a specific aromatic polyamine (for example by neutralization or by distillation) to avoid pollution such as residual aromatic amines or water.

[0104] Preferably, the aniline included in the effluent comprising aromatic compounds 15 reacts with formaldehyde as aldehyde 21 and hydrochloric acid to form diaminodiphenylmethanes and even more preferably, 4,4'-diaminodiphenylmethane (MDA).

[0105] Referring to Figure 2, the device and the method according to the invention (optional step i) of the method according to the invention) may further comprise a toluene disproportionation reaction section 11A making it possible to maximize the production of benzene from the pyrolysis unit 1 and thus to maximize the production of aromatic isocyanates derived from benzene. This unit operation also increases the production of xylenes.

[0106] In the toluene disproportionation reaction section 11A, at least one fraction 22 comprising toluene from the top of the toluene column of the fractionation train 2 feeds at least one disproportionation reactor to produce an effluent enriched in benzene and enriched in xylenes 23. The disproportionation reactor can also be fed with H2 simultaneously. In this case, the effluent enriched in benzene, enriched in xylenes and depleted in toluene can undergo a degassing step to release the residual H2, before being sent to another reaction section of the device according to the invention, and in particular to the reduction reaction section 4. The effluent enriched in benzene and xylenes 23 is sent to the fractionation train 2 at the inlet of the benzene distillation column.

[0107] According to one or more embodiments, the disproportionation reaction section 11A comprises at least one disproportionation reactor adapted to be used under at least one of the following operating conditions:

[0108] - temperature between 200°C and 600°C, preferably between 350°C and 550°C, and even more preferably between 380°C and 500°C;

[0109] - pressure between 0.1 MPa and 10 MPa;

[0110] - PPH between 0.5 and 5 h' 1 .

[0111] The term PPH corresponds to the weight of injected hourly hydrocarbon charge relative to the weight of loaded catalyst.

[0112] According to one or more embodiments, at least one disproportionation reactor is operated in the presence of a catalyst comprising zeolite, for example mordenite. According to one or more embodiments, at least one disproportionation reactor is of the fixed bed type.

[0113] Figure 3 illustrates a schematic representation of a device according to an embodiment according to the present invention for producing toluene diisocyanate (TDI) from an oxygen-rich hydrocarbon feedstock derived from biomass.

[0114] In this embodiment, the device and the method according to the invention (optional step j) of the method according to the invention) may further comprise a transalkylation reaction section 11 B making it possible to maximize the production of toluene from the pyrolysis unit 1 to thus maximize the production of aromatic isocyanates derived from toluene.

[0115] In the transalkylation reaction section 11 B, at least one fraction comprising benzene from the top of the benzene column of the fractionation train 2 is mixed with the cut comprising xylenes from the top of the xylenes column of the fractionation train 2, and feeds via line 24 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).

[0116] The effluent enriched in toluene 25 (relative to the cut comprising benzene and the cut comprising xylenes) from the transalkylation reaction section 11B is sent, in the fractionation train 2, to the inlet of the benzene column, optionally with the aromatic cut.

[0117] According to one or more embodiments, the transalkylation reaction section 11 B comprises at least one transalkylation reactor adapted to be used under at least one of the following operating conditions:

[0118] - temperature between 200°C and 600°C, preferably between 350°C and 550°C, and even more preferably between 380°C and 500°C;

[0119] - pressure between 2 MPa and 10 MPa, preferably between 2 and 6 MPa, and more preferably between 2 MPa and 4 MPa;

[0120] - PPH between 0.5 and 5 h' 1 , preferably between 1 and 4 hours 1 , and more preferably between 2 and 3 hours 1 .

[0121] The term PPH corresponds to the weight of injected hourly hydrocarbon charge relative to the weight of loaded catalyst.

[0122] 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. According to one or more embodiments, the at least one transalkylation reactor is of the fixed bed type.

[0123] Thus the clever combination between on the one hand a pyrolysis unit 1, a WGS reaction section 7, optionally an H2 / CO2 separation section 8, a fractionation train 2, a nitration reaction section 3, a reduction reaction section 4, optionally a condensation reaction section 5, and an isocyanate synthesis reaction section 6 makes it possible to produce aromatic isocyanates from oxygen-rich hydrocarbon compounds such as biomass.

[0124] Examples

[0125] Tables 1 and 2 below illustrate the gains in % of carbon from the starting biomass that can be used in MDI (Table 1) and TDI (Table 2) after pyrolysis of 1000 tonnes per day of biomass. :benzene ir from of biomass li

[0126] For a conventional pyrolysis step, 5.6% by weight of the carbon in the biomass relative to the total weight of the biomass introduced is converted into benzene. For a complete conversion of benzene into MDI, 5.6% by weight of the carbon in the biomass feedstock is recovered as MDI (see Table 1). of bio-sourced MDI from benzene from pyrolysis of liqnocellulosic biomass + recovery of CO via WGS

[0127] Under the following operating conditions:

[0128] • all the benzene produced is converted into MDI; and

[0129] • part of the CO2 output from WGS is used to synthesize MDI from MDA;

[0130] 7% of the carbon in the biomass load is recovered as MDI (see Table 1). of biosourced MDI from benzene from CO accreditation via WGS + di toluene

[0131] The disproportionation step transforms toluene into benzene and xylene.

[0132] Under the following operating conditions:

[0133] • all toluene is converted into xylene and benzene;

[0134] • all the benzene produced is transformed into MDI; and • part of the CO2 leaving WGS is used to synthesize MDI from MDA;

[0135] 9.8% of the carbon in the biomass load is recovered as MDI (see Table 1).

[0136] Table 1

[0137] Example 4 (in accordance with the invention): Synthesis of bio-sourced TPI from toluene from the pyrolysis of lignocellulosic biomass

[0138] For a conventional pyrolysis step, 6.4% by weight of the carbon in the biomass relative to the total weight of the biomass introduced is converted into toluene. For complete conversion of toluene into TDI, 6.4% by weight of the carbon in the biomass feedstock is converted into TDI (see Table 2).

[0139] Example 5 (in accordance with the invention): Synthesis of bio-sourced TDI from toluene from the pyrolysis of lignocellulosic biomass + recovery of CO via WGS

[0140] Under the following operating conditions:

[0141] • all toluene produced is converted to TDI;

[0142] • part of the CO2 output from WGS is used to synthesize TDI from MDA; 8.2% of the carbon from the biomass load is used in TDI (see Table 3).

[0143] Example 6 (in accordance with the invention): Synthesis of bio-sourced TDI from toluene from the pyrolysis of lignocellulosic biomass + recovery of CO via WGS + transalkylation of benzene and xylene Transalkylation makes it possible to transform xylene and benzene into toluene.

[0144] Under the following operating conditions:

[0145] • all benzene and all xylene are converted to toluene

[0146] • all the toluene produced is converted into TDI • part of the CO2 output from WGS is used to synthesize TDI from MDA;

[0147] 22.5% of the carbon in the biomass load is used in TDI (see Table 2).

[0148] Table 2

Claims

CLAIMS 1. Device for converting an oxygen-rich hydrocarbon feedstock from biomass comprising: - a pyrolysis unit (1) adapted to produce from a hydrocarbon feedstock derived from biomass (11) at least one cut comprising aromatic compounds (12), a gaseous effluent comprising at least carbon monoxide (9a), and water (10); - a water gas conversion reaction section WGS (7) adapted to produce a gas stream (18) comprising hydrogen and carbon dioxide from carbon monoxide (9a) and water (10) from the pyrolysis unit (1); - a fractionation train (2) adapted to extract at least one cut comprising benzene, one cut comprising toluene, one cut comprising xylenes, and one cut comprising aromatic compounds with 9 and 10 carbon atoms from said cut comprising aromatic compounds (12); - a nitration reaction section (3) adapted to produce nitro aromatic compounds (14) from at least one cut extracted from said fractionation train (2); - a reduction reaction section (4) adapted to produce aromatic amines (15) from the nitro aromatic compounds (14) and hydrogen from the WGS water gas conversion reaction unit (7); - an isocyanate synthesis reaction section (6) adapted to produce isocyanates (17) from aromatic amines (15) from the reduction reaction section (4), and from carbon dioxide from the water gas conversion reaction section WGS (7), or from carbon monoxide (9b) from the pyrolysis unit (1).

2. Device according to claim 1, further comprising a reaction section for separating (8) said gas stream (18) comprising hydrogen and carbon dioxide into at least one hydrogen-enriched stream (19) and at least one carbon dioxide-enriched stream (20).

3. Device according to one of claims 1 or 2, in which the isocyanate synthesis reaction section (6) is adapted to produce 4,4'-diphenylmethylene diisocyanate (MDI).

4. Device according to claim 3, wherein the nitration reaction section (3) is adapted to produce nitrobenzene from the cut comprising benzene extracted from said fractionation train (2).

5. Device according to one of claims 3 or 4, further comprising a toluene disproportionation reaction section (11 A) adapted to produce a benzene-enriched effluent (23) from the cut comprising toluene from said fractionation train (2).

6. Device according to one of claims 3 to 5, further comprising an aromatic amine condensation reaction section (5) for producing aromatic polyamines from aromatic amines from the reduction reaction section (4) and an aldehyde (21).

7. Device according to one of claims 1 or 2, in which the isocyanate synthesis reaction section (6) is adapted to produce toluene diisocyanate (TDI).

8. Device according to claim 7, wherein the nitration reaction section (3) is adapted to produce dinitrotoluene from the cut comprising toluene extracted from said fractionation train (2).

9. Device according to one of claims 7 or 8, further comprising a transalkylation reaction section (11 B) adapted to produce an effluent enriched in toluene (25) from the cut comprising benzene and the cut comprising xylenes from said fractionation train (2).

10. A method for converting an oxygen-rich hydrocarbon feedstock comprising the following steps: a) a biomass-derived hydrocarbon feedstock (11) is sent to a pyrolysis unit (1) to produce at least one cut comprising aromatic compounds (12), a gaseous effluent comprising at least carbon monoxide (9a), and water (10); b) the carbon monoxide (9a) and the water (10) obtained at the end of step a) are sent to a water gas conversion reaction section WGS (7) to produce a gaseous stream (18) comprising hydrogen and carbon dioxide; c) sending said cut comprising aromatic compounds (12) obtained at the end of step a) into a fractionation train (2) to extract at least one cut comprising benzene, one cut comprising toluene, one cut comprising xylenes, and one cut comprising aromatic compounds with 9 and 10 carbon atoms;d) at least one extracted cut obtained at the end of step c) is sent to a nitration reaction section (3) to produce nitro aromatic compounds (14); e) sending said aromatic nitro compounds (14) obtained at the end of step d) and the hydrogen obtained at the end of step b) into a reduction reaction section (4) to produce aromatic amines (15); f) sending said aromatic amines (15) obtained at the end of step e), and the carbon dioxide obtained at the end of step b), or the carbon monoxide (9b) obtained at the end of step a) into an isocyanate synthesis reaction section (6) to produce isocyanates (17).

11. Method according to claim 10, further comprising a step g) in which said gaseous stream (18) comprising hydrogen and carbon dioxide obtained at the end of step b) is sent to a separation reaction section (8) to obtain at least one hydrogen-enriched stream (19) and at least one carbon dioxide-enriched stream (20).

12. Method according to one of claims 10 or 11, wherein when 4,4'-diphenylmethylene diisocyanate (MDI) is produced in the isocyanate synthesis reaction section (6), said method further comprises a step h) in which the effluent comprising aromatic compounds (15) is sent to a condensation reaction section (5) of the aromatic amines to obtain an effluent comprising aromatic polyamines (16).

13. Method according to claim 12, further comprising a step i) in which at least one fraction comprising toluene (22) from the fractionation train (2) is sent to a toluene disproportionation reaction section (11A) to obtain an effluent enriched in benzene and enriched in xylenes (23).

14. Method according to one of claims 10 or 11, wherein when toluene diisocyanate (TDI) is produced in the isocyanate synthesis reaction section (6), said method further comprises a step j) in which a stream (24) comprising at least one fraction comprising benzene from the fractionation train (2) and at least one fraction of the xylenes from the fractionation train (2) is sent to a transalkylation reaction section (11 B) to obtain an effluent enriched in toluene (25).

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