Toluene methylation with transalkylation of heavy aromatics

Patent metadata

Field	Value
Publication number	US-9783462-B2
Application number	US-201314022643-A
Country	US
Kind code	B2
Filing date	Sep 10, 2013
Priority date	Sep 10, 2013
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

A method of producing a purified mixed xylene comprising: introducing toluene and methanol to an alkylation reactor ( 32 ); reacting the toluene and the methanol in the alkylation reactor ( 32 ) to form a hydrocarbon stream ( 22 ) comprising a first mixed xylene, wherein the alkylation reactor ( 32 ) comprises an alkylation catalyst; separating the hydrocarbon stream ( 22 ) into a toluene stream ( 24 ) and a separated C 8+ stream ( 14 ); introducing the toluene stream ( 24 ) to a transalkylation reactor ( 38 ) with a transalkylation catalyst to produce a transalkylated stream ( 17 ) comprising a second mixed xylene; adding the transalkylated stream ( 17 ) to the hydrocarbon stream ( 22 ); and separating a C 8 product stream ( 19 ) comprising the purified mixed xylene from the separated C 8+ stream ( 14 ).

First claim

We claim:

1. A method of producing a purified mixed xylene comprising:
introducing a toluene stream ( 3 ) and methanol to an alkylation reactor ( 32 ), wherein the toluene stream comprises toluene and 1 wt % to 30 wt % of C 9= aromatics, based upon a total weight of the toluene stream;
reacting the toluene and the methanol in the alkylation reactor ( 32 ) to form a hydrocarbon stream ( 22 ) comprising a first mixed xylene, wherein the alkylation reactor ( 32 ) comprises an alkylation catalyst that comprises a phosphorus containing, medium pore, pentasil zeolite having a silica/alumina ratio of greater than or equal to 200;
separating the hydrocarbon stream ( 22 ) into a toluene stream ( 24 ) and a separated C 8+ stream ( 14 );
introducing the toluene stream ( 24 ) to a transalkylation reactor ( 38 ) with a transalkylation catalyst to produce a transalkylated stream ( 17 ) comprising a second mixed xylene;
adding the transalkylated stream ( 17 ) to the hydrocarbon stream ( 22 ); and
separating a C 8 product stream ( 19 ) comprising the purified mixed xylene from the separated C 8+ stream ( 14 ).

2. The method of claim 1 , wherein the phosphorus is present in an amount of 0.01 to 0.15 g per gram of zeolite.

3. The method of claim 1 , wherein the toluene stream ( 3 ) comprises 5 wt % to 30 wt % of C 9+ aromatics.

4. The method of claim 3 , wherein the toluene stream ( 3 ) comprises 10 wt % to 30 wt % of C 9+ aromatics.

5. The method of claim 1 , wherein greater than or equal to 0.05 g of C 9+ aromatics per gram of toluene converted is produced in the alkylation reactor ( 32 ).

6. The method of claim 1 , wherein the purified mixed xylene comprises greater than or equal to 85 wt % p-xylene based on the total amount of mixed xylene.

7. The method of claim 1 , wherein the reacting the toluene and the methanol is carried out under conditions such that a selectivity for para-xylene of greater than or equal to 80 mol % is achieved.

8. The method of claim 1 , wherein the reacting the toluene and the methanol is carried out under conditions such that a selectivity for para-xylene of less than or equal to 75 mol % is achieved.

9. The method of claim 1 , further comprising separating the C 8+ stream ( 14 ) in a xylene column ( 39 ) into the C 8 product stream ( 19 ) and a separated C 9+ stream ( 18 ).

10. The method of claim 9 , further comprising separating the separated C 9+ stream ( 18 ) in a C 9 separation column ( 40 ) into a C 9 stream ( 20 ) and a C 10+ stream ( 21 ); and introducing the C 9 stream ( 20 ) to the transalkylation reactor ( 38 ).

11. The method of claim 1 , further comprising introducing a C 9+ stream ( 16 ) to the transalkylation reactor ( 38 ).

Assignees

• Saudi Basic Ind Corp

Inventors

• Ghosh Ashim Kumar
• Elbaccouch Mohamed
• Shafiei Mohammad
• Gopalakrishnan Murali

Classifications

• C07C6/123

  of only one hydrocarbon · CPC title

• C07C2529/40

  of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11 · CPC title

• C07C15/08

  Xylenes · CPC title

• C07C2/864 Primary

  the non-hydrocarbon is an alcohol · CPC title

• C07C2/66 Primary

  Catalytic processes · CPC title