Production of xylenes from syngas

Patent metadata

Field	Value
Publication number	US-9809758-B2
Application number	US-201514753734-A
Country	US
Kind code	B2
Filing date	Jun 29, 2015
Priority date	Jul 24, 2014
Publication date	Nov 7, 2017
Grant date	Nov 7, 2017

Abstract

This disclosure relates to the production of xylenes from syngas, in which the syngas is converted to an aromatic product by reaction with a Fischer-Tropsch catalyst and an aromatization catalyst. The Fischer-Tropsch catalyst and aromatization catalyst may be different catalysts or combined into a single catalyst. The aromatic product is then subjected to selective alkylation with methanol and/or carbon monoxide and hydrogen to increase its p-xylene content.

First claim

The invention claimed is:

1. A process for producing xylenes, the process comprising:
(a) providing a first feed comprising hydrogen and carbon monoxide, in which the molar ratio of hydrogen to carbon monoxide is from about 0.5 to 6;
(b) contacting the first feed with (i) a first catalyst comprising 1 to 50 wt % of Fe, and (ii) a second catalyst comprising at least one medium pore size molecular sieve, wherein contacting the first feed with the first catalyst and the second catalyst is carried out under conditions including a temperature from 200° C. to 370° C. and a pressure from 500 to 3000 kPa (absolute) effective to produce a reaction effluent containing benzene and/or toluene; and
(c) reacting at least part of the benzene and/or toluene in the reaction effluent with a second feed comprising (i) methanol and/or (ii) hydrogen and carbon monoxide under conditions effective to produce p-xylene, wherein the reacting is conducted in the presence of a third catalyst comprising at least one molecular sieve having a Diffusion Parameter for 2,2-dimethylbutane of from 0.1 to 15 sec −1 when measured at a temperature of 120° C. and a 2,2-dimethylbutane pressure of 60 torr (8kPa),
wherein the second catalyst is selectivated by contacting the second catalyst with steam at a temperature of at least 950° C. for about 10 minutes to 10 hours.

2. The process of claim 1 , wherein the first catalyst further comprises a support selected from the group consisting of zinc oxide, manganese oxide, alumina, silica, carbon, and mixtures thereof.

3. The process of claim 1 , wherein first catalyst further comprises at least one stabilizer selected from an element or a compound thereof, wherein the element is selected from Groups 1 to 4 of the Periodic Table of the Elements.

4. The process of claim 3 , wherein the element from Groups 1 to 4 of the Periodic Table is selected from the group consisting of Cs, K, and Ca.

5. The process of claim 1 , wherein the second catalyst comprises at least one molecular sieve having a Constraint Index of 1 -12.

6. The process of claim 1 , wherein the at least one medium pore size molecular sieve of the second catalyst comprises ZSM-5.

7. The process of claim 1 , wherein the second catalyst comprises at least one metal or a compound thereof, wherein the metal is selected from the group consisting of Ga, In, Zn, Cu, Re, Mo, W, La, Fe, Ag, Pt, and Pd.

8. The process of claim 1 , wherein the first and second catalysts are located in different reactions beds.

9. The process of claim 1 , wherein the first and second catalysts are different but are located in the same reaction bed.

10. The process of claim 1 , wherein the first and second catalysts are combined into a single multi-functional catalyst.

11. The process of claim 1 , wherein the at least one molecular sieve of the third catalyst comprises ZSM-5.

12. The process of claim 1 , wherein the reacting (c) is conducted under conditions including a temperature from 350 to 700° C., a pressure of from 100 and 7000 kPa absolute, and a weight hourly space velocity of from 0.5 to 300 hr −1 .

13. The process of claim 1 , wherein the first catalyst further comprises 0.1 to 20 wt % of Cu.

Assignees

• Exxonmobil Chemical Patents Inc

Inventors

• Beech Jr James H
• Soultanidis Nikolaos
• Silverberg Steven E

Classifications

• B01J29/076

  containing arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium · CPC title

• C10G2400/30

  Aromatics · CPC title

• C07C15/04

  Benzene · CPC title

• C07C1/0485

  Set-up of reactors or accessories; Multi-step processes · CPC title

• C07C15/08

  Xylenes · CPC title