Production of aromatics by conversion of synthesis gas into methanol and alkylation of toluene

Abstract

Device and method of production and conversion comprising / using: a fractionation train (4-6) producing a xylene cut (24); a xylene separation unit (10) processing the xylene cut to produce a paraxylene extract (39) and a raffinate (40); an isomerization unit (11) processing the raffinate to produce an isomerate (42) of xylene sent to the fractionation train; a synthesis gas production unit (14; 15) processing a hydrocarbon feed (30) to produce a synthesis gas (34) comprising CO and CO2; a methanol synthesis reaction section (50) processing the synthesis gas (34) to produce methanol (51); A toluene alkylation reaction section (13) treats a toluene-containing cut (23) with methanol (51) to produce an alkylation effluent (32) containing xylenes, which is then sent to the fractionation train. Figure 1 to be published

Claims

Claims

1. A method for producing and converting a hydrocarbon feedstock, comprising the following steps: - fractionating a first hydrocarbon feedstock (2) in a fractionation train (4-6) 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 comprising paraxylene (39) 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 (4-6); - treating a second hydrocarbon feedstock (30) in a synthesis gas production unit (14;15) to produce a synthesis gas (34) comprising at least carbon monoxide and carbon dioxide; - treating the synthesis gas (34) in a methanol synthesis reaction section (50) to produce methanol (51); - alkylating at least a portion of the cut comprising toluene (23) with the methanol (51) in a toluene alkylation reaction section (13) and producing an alkylation effluent (32) comprising xylenes sent to the xylene separation unit (10).;

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

3. A method according to claim 2, comprising separating a recycle gas (54) comprising unconverted CO and / or unconverted CO2 in the purification section (52), and recycling said recycle gas (54) to the inlet of the methanol synthesis reaction section (50).

4. Method according to any one of the preceding claims, in which the synthesis gas production unit (14; 15) comprises a pyrolysis unit (14) adapted to produce at least one pyrolysis effluent (21) comprising hydrocarbon compounds of 6 to 10 carbon atoms at least partially feeding the first hydrocarbon feedstock (2).

5. A method according to any preceding claim, comprising providing a hydrogen supply (35) in the synthesis gas (34).

6. A method according to any one of the preceding claims, wherein the synthesis gas production unit (14; 15) comprises: a pyrolysis unit (14) comprising at least one reactor used under at least one of the following operating conditions: - absolute pressure between 0.1 MPa and 0.5 MPa and WH between 0.01 h 1 and 10 h *, preferably between 0.01 h 1 and 5 h *, and very preferably between 0.1 h 1 and 3 h *, the WH is the ratio of the volume flow rate of feedstock to the volume of catalyst used; - temperature between 400°C and 1000°C, preferably between 400°C and 650°C, preferably between 450°C and 600°C and preferably between 450°C and 590°C;- zeolitic catalyst comprising and preferably consisting of at least one zeolite chosen from ZSM-5, ferrierite, Beta zeolite, Y zeolite, mordenite, ZSM-23, ZSM-57, EU-1, ZSM-11 and preferably the catalyst is a catalyst comprising only ZSM-5; or an oxycombustion unit (15) comprising at least one reactor used in at least one of the following operating conditions: - a reactor operating in a fluidized bed; - temperature between 500°C and 1000°C; - pressure between 0.1 MPa and 3 MPa, preferably between 0.1 MPa and 1 MPa; or; a gasification unit comprising at least one gasification furnace used in at least one of the following operating conditions: - temperature between 700°C and 1400°C.

7. A method according to any one of the preceding claims, wherein the methanol synthesis reaction section (50) comprises at least one reactor used under at least one of the following operating conditions: - temperature between 200°C and 450°C, preferably between 220°C and 400°C, and more preferably still between 250°C and 350°C; - pressure between 1 MPa and 12 MPa, preferably between 2 MPa and 10 MPa, and more preferably between 5 MPa and 10 MPa; - hydrogen to COX molar ratio in which COX represents CO and CO2, between 3 and 10, preferably between 3 and 7, very preferably between 3 and 5; - - gas space velocity at the reactor inlet between 0.2 g / gcata / h and 1 g / gcata / h.

8. A method according to any one of the preceding claims, wherein the toluene alkylation reaction section (13) comprises at least one alkylation reactor used under at least one of the following operating conditions: - temperature between 20°C and 550°C; - pressure between 1 MPa and 10 MPa; - toluene / methanol molar ratio between 1 and 5; - PPH between 0.5 h 1 and 50 h 1; - presence of a catalyst comprising a zeolite.

9. A method according to any one of the preceding claims, wherein the isomerization unit (11) comprises a gas-phase isomerization zone used under at least one of the following operating conditions: - temperature above 300°C; - pressure below 4.0 MPa; - hourly space velocity below 10 h 1; - hydrogen to hydrocarbon molar ratio below 10; - presence of a catalyst comprising at least one zeolite having channels whose opening is defined by a ring with 10 or 12 oxygen atoms, and at least one metal from group VIIIB with a content of between 0.1 and 0.3% by weight, limits included.

10. A method according to any preceding claim, wherein the isomerization unit (11) comprises a liquid phase isomerization zone used under at least one of the following operating conditions: - temperature below 300 C; - pressure less than 4 MPa; - hourly space velocity less than 100 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.

11. Device for producing and converting a hydrocarbon feedstock, comprising: - a fractionation train (4-6) adapted to extract at least one cut comprising benzene (22), a cut comprising toluene (23) and a 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 comprising paraxylene (39) 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 (4-6); - a synthesis gas production unit (14; 15) adapted to treat a second hydrocarbon feedstock (30) and produce a synthesis gas (34) comprising at least carbon monoxide and carbon dioxide; - a methanol synthesis reaction section (50) adapted to treat the synthesis gas (34) and produce methanol (51); - a toluene alkylation reaction section (13) adapted to treat at least a portion of the cut comprising toluene (23) with the methanol (51) and produce an alkylation effluent (32) comprising xylenes sent to the xylene separation unit (10).

12. Apparatus according to claim 11, wherein the toluene alkylation reaction section (13) is adapted to separate xylenes from a water-containing cut (31) to produce the alkylation effluent (32).

13. Apparatus according to claim 11 or claim 12, further comprising a feed separation unit (1) for separating the feed (2) into a hydrocarbon fraction with 7 carbon atoms or less (16) sent to the benzene column (4) of the fractionation train (4-6), and an aromatic fraction with 8 carbon atoms or more (17) sent to the xylene column (6) of the fractionation train (4-6).

14. Apparatus according to claim 13, further comprising an aromatics extraction unit (3) between the charge separation unit (1) and the benzene column (4) for separating aliphatic compounds (19) from the aromatic fraction with 7 carbon atoms or less (16) and producing an extract (20) sent to the benzene column (4).

15. Conversion device according to any one of claims 11 to 14, further comprising a stabilization column (12) adapted to remove a cut of volatile species (45) from the effluents of the isomerization unit (11).

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