Aromatization process using heavy aromatic circulation

Patent metadata

Field	Value
Publication number	US-11008266-B2
Application number	US-201916564314-A
Country	US
Kind code	B2
Filing date	Sep 9, 2019
Priority date	Apr 13, 2018
Publication date	May 18, 2021
Grant date	May 18, 2021

Abstract

Disclosed are a catalytic method and system for producing aromatic hydrocarbons from aliphatic hydrocarbons or light naphtha. In an aspect, the process comprises adding a diluent comprising a heavy aromatic hydrocarbon (for example, C 7 -C 9+ ) to a reactor feedstock comprising aliphatic hydrocarbons (for example, C 6 -C 8 ) or light naphtha to form a reactor feed stream, such that the heat capacity of reactor feed stream is higher than the heat capacity of feedstock. The reactor feed stream is heated and contacting with a catalyst under conditions sufficient to aromatize at least a portion of the aliphatic hydrocarbons and form a product stream comprising a primary aromatic hydrocarbon product and a heavy aromatic hydrocarbon product. In an aspect, the diluent can comprise a heavy aromatic hydrocarbon having at least one carbon atom more than the primary aromatic hydrocarbon product.

First claim

What is claimed is:

1. A catalytic hydrocarbon reforming system comprising:
a fractionator having an inlet to receive an initial feedstock comprising naphtha and an outlet to discharge a reactor feedstock comprising aliphatic hydrocarbons;
a diluent input line for adding a diluent comprising a heavy aromatic hydrocarbon to the reactor feedstock to form a reactant feed stream having a first temperature;
at least one furnace capable of heating the reactant feed stream to a second temperature;
at least one reactor charged with a catalyst comprising an inorganic support, a Group 8-10 metal, and at least one halide, the reactor having an inlet to receive the reactant feed stream and an outlet to discharge a reactor effluent stream at a third temperature; the reactor effluent stream comprising a primary aromatic hydrocarbon product and a heavy aromatic hydrocarbon product;
a separation system that receives the reactor effluent stream and separately discharges the primary aromatic hydrocarbon product, the heavy aromatic hydrocarbon product, hydrogen, and a raffinate; and
a first return line extending from the separation system to the diluent input line for providing the diluent, the diluent comprising at least a portion of the heavy aromatic hydrocarbon product.

2. A catalytic hydrocarbon reforming system according to claim 1 , wherein the reactor feedstock and the reactant feed stream comprise C 6 to C 8 aliphatic hydrocarbons.

3. A catalytic hydrocarbon system according to claim 1 , wherein the reactor feedstock and the reactant feed stream comprise light naphtha.

4. A catalytic hydrocarbon reforming system according to claim 1 , wherein the primary aromatic hydrocarbon product comprises benzene and the heavy aromatic hydrocarbon product comprises toluene and xylenes.

5. A catalytic hydrocarbon reforming system according to claim 1 , further comprising a second return line extending from the separation system, wherein the second return line is configured to provide the raffinate to the fractionator inlet.

6. A catalytic hydrocarbon reforming system according to claim 1 , further comprising a third return line extending from the separation system, wherein the third return is configured to provide hydrogen to the reactant feed stream.

7. A catalytic hydrocarbon reforming system according to claim 1 , further comprising a third return line extending from the separation system, wherein the third return line is configured to first provide hydrogen to a dryer and is configured to subsequently provide the dried hydrogen to the reactant feed stream.

8. A catalytic hydrocarbon reforming system according to claim 1 , further comprising a sulfur converter-absorber between the fractionator and the diluent input line.

9. A catalytic hydrocarbon reforming system according to claim 1 , wherein the system is absent a recycle line compressor.

10. A catalytic hydrocarbon reforming system according to claim 1 , wherein the first temperature is within from about 10° F. to about 90° F. from the second temperature.

11. A catalytic hydrocarbon reforming system according to claim 1 , wherein the reactant feed stream has a higher heat capacity than the reactor feedstock.

12. A catalytic hydrocarbon reforming system according to claim 11 , wherein the system is configured so that the heat duty provided by the furnace to the reactor feed stream is reduced by at least 5% as compared to the heat duty provided when the reactant feed stream does not have a higher heat capacity than the reactor feedstock.

13. A catalytic hydrocarbon reforming system according to claim 1 , wherein the reactor is a radial flow reactor.

14. A catalytic hydrocarbon reforming system according to claim 1 , wherein the inorganic support comprises a zeolite, a silica-bound zeolite, a clay mineral, silica, alumina, silica-alumina, aluminum phosphate, a heteropolytungstate, titania, zirconia, magnesia, boria, zinc oxide, mixed oxides thereof, or mixtures thereof.

15. A catalytic hydrocarbon reforming system according to claim 1 , wherein the inorganic support comprises L-zeolite, X-zeolite, Y-zeolite, omega zeolite, beta zeolite, ZSM-4, ZSM-5, ZSM-10, ZSM-11, ZSM-12, ZSM-20, REY, USY, RE-USY, LZ-210, LZ-210-A, LZ-210-M, LZ-210-T, SSZ-24, SSZ-26, SSZ-31, SSZ-33, SSZ-35, SSZ-37, SSZ-41, SSZ-42, SSZ-44, MCM-58, mordenite, mazzite, faujasite, or combinations thereof.

16. A catalytic hydrocarbon reforming system according to claim 1 , wherein the catalyst comprises a Group 8-10 metal selected independently from ruthenium, rhodium, palladium, osmium, iridium, platinum, or any combination thereof.

17. A catalytic hydrocarbon reforming system according to claim 1 , wherein the halide comprises fluoride, chloride, or a combination thereof.

18. A catalytic hydrocarbon reforming system according to claim 1 , wherein the system further comprises a purifier configured to remove one or more impurities from the reactor feedstock to form a purified reactor feedstock stream, and wherein the diluent input line is configured to add the diluent to the purified reactor feedstock stream to form the reactant feed stream.

19. A catalytic hydrocarbon reforming system according to claim 18 , wherein the purifier is a sulfur removal system.

20. A catalytic hydrocarbon reforming system according to claim 19 , wherein the purifier is a sulfur converter-absorber.

Assignees

• Chevron Phillips Chemical Co Lp

Inventors

• Weber Eric P

Classifications

• C07C5/417 Primary

  of the platinum group · CPC title

• C07C5/31 Primary

  changing the number of rings · CPC title

• B01J2219/24

  Stationary reactors without moving elements inside · CPC title

• C07C5/415

  with metals · CPC title

• B01J19/24

  Stationary reactors without moving elements inside (B01J19/08, B01J19/26 take precedence; with stationary particles B01J8/02) · CPC title