Apparatus and process for converting aromatic compounds by benzene alkylation with ethanol

Patent metadata

Field	Value
Publication number	US-11407696-B2
Application number	US-202017124087-A
Country	US
Kind code	B2
Filing date	Dec 16, 2020
Priority date	Dec 17, 2019
Publication date	Aug 9, 2022
Grant date	Aug 9, 2022

Abstract

Apparatus and process for converting aromatic compounds, comprising/using: a fractionating train (4-7) suitable for extracting at least one benzene-comprising fraction (22), one toluene-comprising fraction (23) and one fraction (24) comprising xylenes and ethylbenzene from the feedstock (2); a xylene separating unit (10) suitable for treating the fraction comprising xylenes and ethylbenzene and producing a para-xylene-comprising extract (39) and a raffinate (40) comprising ortho-xylene, meta-xylene and ethylbenzene; an isomerizing unit (11) for treating the raffinate and producing a para-xylene-enriched isomerizate (42), which is sent to the fractionated train; and an alkylating reaction section (13) for treating at least part of the benzene-comprising fraction with an ethanol source (30) and producing an alkylation effluent (31) comprising ethylbenzene, which is sent to the isomerizing unit.

First claim

The invention claimed is:

1. A conversion apparatus for converting a feedstock ( 2 ) of aromatic compounds, comprising:
a fractionating train ( 4 - 7 ) suitable for extracting at least one fraction comprising benzene ( 22 ), one fraction comprising toluene ( 23 ) and one fraction comprising xylenes and ethylbenzene ( 24 ) from the feedstock ( 2 );
a xylene separating unit ( 10 ) suitable for treating the fraction comprising xylenes and ethylbenzene ( 24 ) and for producing an extract ( 39 ) comprising para-xylene and a raffinate ( 40 ) comprising ortho-xylene, meta-xylene and ethylbenzene;
an isomerizing unit ( 11 ) suitable for treating the raffinate ( 40 ) and producing a para-xylene-enriched isomerizate ( 42 ), which is sent to the fractionating train ( 4 - 7 ); and
an alkylating reaction section ( 13 ) suitable for treating at least part of the fraction comprising benzene ( 22 ) with an ethanol source ( 30 ) and producing an alkylating effluent ( 31 ) comprising ethylbenzene, which is sent to the isomerizing unit ( 11 ).

2. The conversion apparatus according to claim 1 , further comprising a transalkylating reaction section ( 14 ) suitable for transalkylating polyethylbenzenes present in the alkylation effluent ( 31 ) and producing an ethylbenzene-enriched fraction ( 32 ; 47 ).

3. The conversion apparatus according to claim 2 , further comprising a fractionating unit ( 15 ) suitable for treating the alkylation effluent ( 31 ) and producing a plurality of fractionation fractions comprising at least one ethylbenzene fraction ( 33 ), which is sent to the isomerizing unit ( 11 ), one aqueous fraction ( 34 ) comprising water, and one benzene fraction ( 35 ).

4. The conversion apparatus according to claim 3 , wherein the fractioning unit ( 15 ) is disposed downstream of the transalkylating reaction section ( 14 ) and is suitable for treating the ethylbenzene-enriched fraction ( 32 ; 47 ).

5. The conversion apparatus according to claim 3 , wherein the fractionating unit ( 15 ) is suitable for producing additionally at least one polyethylbenzene fraction ( 36 ), and wherein the transalkylating reaction section ( 14 ) is disposed downstream of the fractionating unit ( 15 ) and is suitable for treating at least part of said polyethylbenzene fraction ( 36 ).

6. The conversion apparatus according to claim 1 , wherein the fractionated train ( 4 - 7 ) is suitable for extracting a C9-C10 monoaromatics fraction ( 25 ) from the feedstock ( 2 ).

7. The conversion apparatus according to claim 6 , further comprising a transalkylating unit ( 8 ) suitable for treating the C9-C10 monoaromatics fraction ( 25 ) with the fraction comprising toluene ( 23 ) and producing xylenes, which are sent to the fractionating train ( 4 - 7 ).

8. The conversion apparatus according to claim 1 , further comprising a disproportionating unit ( 48 ) suitable for treating the fraction comprising toluene ( 23 ) and producing a xylene-enriched fraction ( 50 ), which is recycled to the isomerizing unit ( 11 ).

9. A conversion process for converting a feedstock ( 2 ) of aromatic compounds, comprising the following steps:
fractionating the feedstock in a fractionating train ( 4 - 7 ) to extract at least one fraction comprising benzene ( 22 ), one fraction comprising toluene ( 23 ) and one fraction comprising xylenes and ethylbenzene ( 24 );
separating the fraction comprising xylenes and ethylbenzene ( 24 ) in a xylene separating unit ( 10 ) and producing an extract ( 39 ) comprising para-xylene and a raffinate ( 40 ) comprising ortho-xylene, meta-xylene and ethylbenzene;
isomerizing the raffinate ( 40 ) in an isomerizing unit ( 11 ) and producing a para-xylene-enriched isomerizate ( 42 );
sending the para-xylene-enriched isomerizate ( 42 ) to the fractionating train ( 4 - 7 );
alkylating at least part of the fraction comprising benzene ( 22 ) with an ethanol source ( 30 ) in an alkylating reaction section ( 13 ) and producing an alkylation effluent ( 31 ) comprising ethylbenzene; and
sending the alkylation effluent ( 31 ) comprising ethylbenzene to the isomerizing unit ( 11 ).

10. The conversion process according to claim 9 , wherein the alkylating reaction section ( 13 ) comprises at least one alkylation reactor, which is used under the following operating conditions:
temperature of between 20° C. and 400° C.;
pressure of between 1 and 10 MPa;
molar benzene/ethanol ratio of between 3 and 15;
WWH of between 0.5 and 50 h −1 .

11. The conversion process according to claim 10 , wherein the alkylation reactor is operated in the presence of a catalyst comprising a zeolite.

12. The conversion process according to claim 9 , wherein the isomerizing unit ( 11 ) comprises a gas-phase isomerization zone and/or a liquid-phase isomerization zone,
wherein the gas-phase isomerization zone is used under the following operating conditions:
temperature of greater than 300° C.;
pressure of less than 4.0 MPa;
hourly space velocity of less than 10 h −1 ;
molar hydrogen-to-hydrocarbon ratio of less than 10;
in the presence of a catalyst comprising at least one zeolite having channels whose opening is defined by a ring of 10 or 12 oxygen atoms, and at least one group VIII metal in an amount of between 0.1 and 0.3 weight %, endpoints included, and

wherein the liquid-phase isomerization zone is used under the following operating conditions:
temperature of less than 300° C.;
pressure of less than 4 MPa;
hourly space velocity of less than 10 h −1 ;
in the presence of a catalyst comprising at least one zeolite having channels whose opening is defined by a ring of 10 or 12 oxygen atoms.

13. The conversion process according to claim 9 , further comprising the following step:
transalkylating polyethylbenzenes present in the alkylation effluent ( 31 ) in a transalkylating reaction section ( 14 ) and producing an ethylbenzene-enriched fraction ( 32 ; 47 ), and
sending the ethylbenzene-enriched fraction ( 32 ; 47 ) to the isomerizing unit ( 11 ).

14. The conversion process according to claim 13 , wherein the transalkylating reaction section ( 14 ) comprises at least one transalkylation reactor, which is used under the following operating conditions:
temperature of between 200° C. and 400° C.;
pressure of between 1 and 6 MPa;
WWH of between 0.5 and 5 h −1 .

15. The conversion process according to claim 14 , wherein the transalkylation reactor ( 14 ) is operated in the presence of a catalyst comprising a zeolite.

16. The conversion apparatus according to claim 1 , further comprising a fractionating unit ( 15 ) suitable for treating the alkylation effluent ( 31 ) and producing a plurality of fractionation fractions comprising at least one ethylbenzene fraction ( 33 ), which is sent to the isomerizing unit ( 11 ), one aqueous fraction ( 34 ) comprising water, and one benzene fraction ( 35 ).

17. The conversion apparatus according to claim 1 , wherein
the fractionating train comprises four columns including a benzene column ( 4 ) for producing the fraction comprising benzene ( 22 ), a toluene column ( 5 ) for producing the fraction comprising toluene ( 23 ), a xylene column ( 6 ) for producing the fraction comprising xylenes and ethylbenzene ( 24 ), and a heavy aromatic column ( 7 ) for producing a C9-C10 monoaromatics fraction ( 25 );
the xylene separating unit ( 10 ) comprises a crystallization unit or simulated moving bed unit;
the isomerizing unit ( 11 ) comprises a gas-phase isomerization zone, a liquid-phase isomerization zone, or both a gas-phase isomerization zone and a liquid-phase isomerization

Assignees

• Ifp Energies Now

Inventors

• Joly Jean-Francois
• Feugnet Frederic

Classifications

• B01J19/245

  placed in series · CPC title

• C07C7/04

  by distillation · CPC title

• C07C5/2708

  with crystalline alumino-silicates, e.g. molecular sieves · CPC title

• C07C5/2737

  with crystalline alumino-silicates, e.g. molecular sieves · CPC title

• C07C5/2775

  with crystalline alumino-silicates, e.g. molecular sieves · CPC title