Aromatic alkylation process

Patent metadata

Field	Value
Publication number	US-11078133-B2
Application number	US-201916705791-A
Country	US
Kind code	B2
Filing date	Dec 6, 2019
Priority date	Dec 6, 2019
Publication date	Aug 3, 2021
Grant date	Aug 3, 2021

Abstract

Processes and apparatuses for alkylating aromatic hydrocarbons with an alkylating reagent to produce an alkylated aromatic product are described. The processes and apparatuses use a riser reactor operated at a superficial velocity of 10 m/s to 25 m/s to produce the alkylated aromatic product. In some embodiments, a combination of steam and aromatic hydrocarbon is used to lift the catalyst.

First claim

What is claimed is:

1. A process for alkylating an aromatic hydrocarbon with an alkylating reagent to produce an alkylated aromatic product, comprising:
passing an aromatic hydrocarbon feed stream comprising an aromatic hydrocarbon and an alkylating reagent feed stream comprising an alkylating reagent to a riser reactor operated at a superficial velocity of 10 m/s to 25 m/s in the presence of a catalyst to produce a reaction mixture comprising the alkylated aromatic product, light olefins, and unreacted aromatic hydrocarbon, wherein the riser reactor comprises an operating catalyst density of about 325 kg/m 3 to 600 kg/m 3 ; and
recovering the alkylated aromatic product.

2. The process of claim 1 further comprising introducing one or more of steam or additional aromatic hydrocarbon into the riser reactor at a location in the riser reactor above where the aromatic hydrocarbon feed stream and the alkylating reagent feed stream are introduced.

3. The process of claim 1 , wherein the riser reactor operates at a temperature of about 300° C. to about 700° C.

4. The process of claim 1 , wherein the riser reactor operates at a pressure of about 68 kPa(g) to about 1378 kPa (g).

5. The process of claim 1 wherein the riser reactor has a residence time of about 0.5 seconds to about 6 seconds.

6. The process of claim 2 wherein the aromatic hydrocarbon comprises toluene and the alkylating reagent comprises methanol, and wherein a molar ratio of toluene to methanol is less than 4.

7. The process of claim 1 , wherein a weight hourly space velocity of the riser reactor is about 10 hr −1 to about 30 hr −1 .

8. The process of claim 1 , wherein the riser reactor comprises a plurality of injection zones.

9. The process of claim 1 , wherein the riser reactor comprises one to four alkylating reagent injection points.

10. The process of claim 1 , wherein recovering the alkylated aromatic product comprises:
separating the reaction mixture in a light olefins column into a light olefins overhead stream comprising the light olefins and a light olefins bottom stream comprising the alkylated aromatic product and the unreacted aromatic hydrocarbon.

11. The process of claim 10 , further comprising:
separating the light olefins bottom stream in an aromatics column into an aromatics overhead stream comprising the unreacted aromatic hydrocarbon and an aromatics bottom stream comprising the alkylated aromatic product.

12. The process of claim 11 , further comprising:
recycling the aromatics overhead stream to the riser reactor.

13. The process of claim 1 , wherein the aromatic hydrocarbon feed stream comprises toluene, the alkylating reagent comprises methanol, and the alkylated aromatic product comprises xylene, and wherein a para-xylene/xylene ratio of the alkylated aromatic product is greater than 0.90.

14. The process of claim 1 wherein the alkylating reagent comprises methanol, and wherein passing the alkylating reagent feed stream to the riser reactor comprises:
passing the alkylating reagent feed stream to a pre-reactor to produce dimethyl ether and water; and
passing the dimethyl ether and water to the riser reactor.

15. The process of claim 1 further comprising:
regenerating the catalyst in a regenerator; and
introducing the regenerated catalyst into the riser reactor wherein between 0.5 and 4 wt % coke is present on the regenerated catalyst.

16. The process of claim 1 further comprising introducing a stream comprising a combination of steam and the aromatic hydrocarbon into the riser reactor, and wherein a cost of utilities for the riser reactor is reduced by at least 10% compared to introducing a stream comprising 100% steam.

17. A process for alkylating an aromatic hydrocarbon with an alkylating reagent comprising methanol to produce an alkylated aromatic product, comprising:
passing an aromatic hydrocarbon feed stream comprising toluene and a methanol feed stream to a riser reactor operated at a superficial velocity of 8 m/s to 25 m/s in the presence of a catalyst to produce a reaction mixture comprising the alkylated aromatic product comprising xylene, light olefins, and unreacted toluene, wherein an operating catalyst density is about 325 kg/m 3 to 600 kg/m 3 and a para-xylene/xylene ratio of the alkylated aromatic product is greater than 0.90;
separating the reaction mixture in a light olefins column into a light olefins overhead stream comprising the light olefins and a light olefins bottom stream comprising the alkylated aromatic product and the unreacted toluene;
separating the light olefins bottom stream in an aromatics column into an aromatics overhead stream comprising the unreacted toluene and an aromatics bottom stream comprising the aromatics product; and
recycling the aromatics overhead stream to the riser reactor.

18. The process of claim 17 wherein riser reactor conditions comprise one or more of: a temperature of about 300° C. to about 700° C.; a pressure of about 68 kPa(g) to about 1378 kPa (g); a residence time of about 0.5 seconds to about 6 seconds; an operating catalyst density of about 25 kg/m 3 to 600 kg/m 3 ; a molar ratio of toluene to methanol is less than 4; or a weight hourly space velocity of about 10 hr −1 to about 30 hr −1 .

19. The process of claim 17 further comprising introducing a stream comprising a combination of steam and the aromatic hydrocarbon into the riser reactor, and wherein a cost of utilities for the riser reactor is reduced by at least 10% compared to introducing a stream comprising 100% steam.

Assignees

• Uop Llc

Inventors

• Kuzmanich Gregory B
• Johnson Ii Richard A
• Montalbano Joseph A
• Xu Feng
• Tsai Robert E

Classifications

• 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

• B01J8/1845

  with particles moving upwards while fluidised · CPC title