Aromatization of light hydrocarbons using metal-doped zeolite catalysts with enhanced mesoporosity

Patent metadata

Field	Value
Publication number	US-11465950-B2
Application number	US-202017011008-A
Country	US
Kind code	B2
Filing date	Sep 3, 2020
Priority date	Sep 3, 2020
Publication date	Oct 11, 2022
Grant date	Oct 11, 2022

Abstract

According to embodiments, a process for aromatizing hydrocarbons may include contacting the hydrocarbons with a zinc- or gallium-doped ZSM-5 catalyst having a mesopore volume of greater than 0.09 cm3/g. Contacting the hydrocarbons with the catalyst causes a least a portion of the hydrocarbons to undergo chemical reactions to form aromatic hydrocarbons.

First claim

What is claimed is:

1. A process for aromatizing hydrocarbons comprising:
contacting the hydrocarbons with a catalyst comprising a zinc- or gallium-doped ZSM-5 zeolite having a mesopore volume of greater than 0.09 cm 3 /g and less than 0.20 cm 3 /g, wherein the ZSM-5 zeolite is desilicated, wherein contacting the hydrocarbons with the catalyst causes a least a portion of the hydrocarbons to undergo chemical reactions to form aromatic hydrocarbon products, and wherein at least 60% of the hydrocarbons form benzene, toluene, ethylbenzene, xylene, or combinations thereof.

2. The process according to claim 1 , wherein the hydrocarbons have 2 carbon atoms to 12 carbon atoms.

3. The process according to claim 2 , wherein the hydrocarbons comprise paraffins, olefins, naphthenes, alkylbenzenes, and combinations thereof.

4. The process according to claim 3 , wherein the hydrocarbons comprise paraffinic hydrocarbons have from 4 carbon atoms to 7 carbon atoms.

5. The process according to claim 1 , wherein the catalyst comprises from 1 wt. % to 30 wt. % zinc and/or gallium dopant.

6. The process according to claim 1 , wherein the catalyst comprises from 2 wt. % to 5 wt. % zinc and/or gallium dopant.

7. The process according to claim 1 , further comprising:
treating the desilicated zinc- or gallium-doped ZSM-5 zeolite under a flow of hydrogen or nitrogen at a temperature from 400° C. to 700° C. for a duration from 1 to 5 hours before contacting the hydrocarbons with the catalyst.

8. The process according to claim 1 , wherein the hydrocarbons comprise straight run light naphtha.

9. The process according to claim 1 , wherein the hydrocarbons comprise aromatic and naphthenic hydrocarbons in minor proportions by volume.

10. The process according to claim 1 , wherein the contacting the hydrocarbons with the catalyst is performed at a weight hourly space velocity (WHSV) from 1.0 to 20.0 h −1 , a temperature from 200° C. to 600° C., and a pressure from 1.0 bar to 30.0 bars.

11. The process according to claim 1 , wherein the aromatic hydrocarbon products comprise benzene, toluene, ethylbenzene, xylene, or combinations thereof.

12. The process according to claim 1 , wherein the desilicated zinc- or gallium-doped ZSM-5 zeolite has a silica to alumina molar ratio from 5:1 to 50:1.

13. The process according to claim 1 , wherein the ZSM-5 zeolite is doped with zinc or gallium after desilication of the ZSM-5 zeolite.

14. The process according to claim 1 , wherein the catalyst has a BET surface area of from 100 m 2 /g to 380 m 2 /g.

Assignees

• Saudi Arabian Oil Co
• Univ King Fahd Pet & Minerals

Inventors

• Jin Yaming
• Qureshi Ziyauddin S
• Aitani Abdullah M
• Koseoglu Omer Refa
• Akhtar Mohammad Naseem
• Alasiri Hassan Saeed Al-Awad

Classifications

• C10G2300/70

  Catalyst aspects · CPC title

• C07C2529/04

  having base-exchange properties, e.g. crystalline zeolites, pillared clays · CPC title

• C10G35/095

  containing crystalline alumino-silicates, e.g. molecular sieves {(C10G35/065 takes precedence)} · CPC title

• B01J29/405 Primary

  containing rare earth elements, titanium, zirconium, hafnium, zinc, cadmium, mercury, gallium, indium, thallium, tin or lead · CPC title

• C07C2523/08

  of gallium, indium or thallium · CPC title