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

Patent metadata

Field	Value
Publication number	US-11247950-B2
Application number	US-202017123360-A
Country	US
Kind code	B2
Filing date	Dec 16, 2020
Priority date	Dec 17, 2019
Publication date	Feb 15, 2022
Grant date	Feb 15, 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 fractionating train; and an alkylating reaction section (13) for treating at least part of the benzene-comprising fraction with an ethylene source (30) and producing an alkylation effluent (31) comprising ethylbenzene, which is sent to the isomerizing unit.

First claim

The invention claimed is:

1. An apparatus suitable 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 a source of ethylene ( 30 ) and producing an alkylating effluent ( 31 ) comprising ethylbenzene, which is sent to the isomerizing unit ( 11 ).

2. The 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 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 ), and one benzene fraction ( 35 ).

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

7. The 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 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 process converting a feedstock ( 2 ) of aromatic compounds, comprising:
fractionating the feedstock in a fractionating train ( 4 - 7 ) to extract at least one fraction comprising benzene ( 22 ), one the 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 a para-xylene-comprising extract ( 39 ) 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 a source of ethylene ( 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 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/ethylene ratio of between 2 and 10;
WWH of between 0.5 and 50 h −1 .

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

12. The 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 (HSV) 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 (HSV) 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 process according to claim 9 , further comprising:
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 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 process according to claim 14 , wherein the transalkylation reactor ( 14 ) is operated in the presence of a catalyst comprising a zeolite.

Assignees

• Ifp Energies Now

Inventors

• Joly Jean-Francois
• Feugnet Frederic

Classifications

• C07C5/2775

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

• C07C5/2708

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

• B01D15/185

  characterised by the components to be separated · CPC title

• B01D3/143

  by two or more of a fractionation, separation or rectification step · CPC title

• C07C7/09

  by fractional condensation · CPC title