Conversion of acetylene and methanol to aromatics

Patent metadata

Field	Value
Publication number	US-9783463-B2
Application number	US-201514829199-A
Country	US
Kind code	B2
Filing date	Aug 18, 2015
Priority date	Sep 30, 2014
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

Methods are provided for forming aromatic compounds from a highly unsaturated aliphatic feeds optionally in combination with methanol. The method can include dehydrogenating a feed containing at least about 50 vol % C 1 -C 4 alkanes under dehydrogenation conditions to form a dehydrogenation effluent containing at least about 25 vol % alkynes. Alternatively, other sources of alkyne-containing feeds can be used. At least a portion of the alkyne-containing feed can then be converted under effective conversion conditions to form a conversion effluent comprising a hydrocarbon product containing aromatic compounds.

First claim

What is claimed is:

1. A method for forming aromatic compounds, comprising:
dehydrogenating a feed comprising at least about 75 vol % ethane, under dehydrogenation conditions to form a dehydrogenation effluent containing at least about 25 vol % alkynes and wherein at least some of the alkynes comprise acetylene, the dehydrogenation conditions including a temperature of at least about 1000° C.; and
converting at least a portion of the dehydrogenation effluent under effective conversion conditions with an aromatization catalyst to form a conversion effluent comprising a hydrocarbon product containing aromatic compounds, wherein a volume percentage of aromatic compounds in the hydrocarbon product are at least about 10 vol % greater than a volume percentage of aromatic compounds in the dehydrogenation effluent, and wherein a molar ratio of acetylene to methanol provided to the aromatization catalyst is 5:1 or less, wherein the converting comprises reacting methanol molecules with acetylene molecules to form methyl acetylene, and reacting an additional acetylene with the methyl acetylene to form para-xylene.

2. The method of claim 1 , wherein dehydrogenating the feed comprises dehydrogenating the feed in a reverse flow reaction system.

3. The method of claim 1 , wherein the effective conversion conditions comprise exposing the dehydrogenation effluent to a molecular sieve at a temperature of about 300° C. to about 700° C. and a total pressure of about 100 kPag to about 7000 kPag.

4. The method of claim 1 , wherein the aromatization catalyst is selectivated to enhance yield of para-xylene.

5. The method of claim 1 , wherein the dehydrogenation conditions comprise partial oxidation conditions.

6. The method of claim 5 , wherein the dehydrogenation effluent also comprises H 2 and CO, the method further comprising:
separating the dehydrogenation effluent to form a syngas-enriched stream having a greater concentration of H 2 and CO than the dehydrogenation effluent, and an acetylene-enriched stream having a greater concentration of acetylene than the dehydrogenation effluent; and
exposing the syngas-enriched stream to effective conditions for formation of methanol to form a methanol-containing stream;
wherein the converting comprises feeding at least a portion of the acetylene-enriched stream and at least a portion of the methanol-containing stream to the aromatization catalyst to form a second conversion effluent.

7. The method of claim 1 , wherein the dehydrogenation conditions comprise pyrolysis conditions.

8. The method of claim 7 , wherein the dehydrogenation effluent has a ratio of alkynes to alkenes of about 1:2 to about 2:1.

9. The method of claim 7 , wherein the dehydrogenation effluent has a ratio of alkynes to alkenes of at least about 3:1.

10. The method of claim 1 , wherein less than about 50 wt. % of the alkenes present in the feed are reacted under the conversion conditions.

11. The method of claim 1 , wherein the aromatization catalyst comprises ZSM-5 and at least one Group 8-14 element.

Assignees

• Exxonmobil Chemical Patents Inc

Inventors

• Hershkowitz Frank
• Brown Stephen H
• Keusenkothen Paul F
• Beutel Tilman W
• Mccarthy Stephen J
• Daage Michel
• Vijay Rohit
• Ilias Samia

Classifications

• C07C2/864 Primary

  the non-hydrocarbon is an alcohol · CPC title

• C07C5/35

  Formation of carbon-to-carbon triple bonds only · 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

• C07C11/24

  Acetylene (production of acetylene gas by wet methods C10H) · CPC title