Olefin methylation for production of low aromatic gasoline

Patent metadata

Field	Value
Publication number	US-11674089-B2
Application number	US-202017014999-A
Country	US
Kind code	B2
Filing date	Sep 8, 2020
Priority date	Sep 24, 2019
Publication date	Jun 13, 2023
Grant date	Jun 13, 2023

Abstract

Systems and methods are provided for conversion of a combined feed of oxygenates (such as methanol or dimethyl ether) and olefins to a high octane naphtha boiling range product with a reduced or minimized aromatics content. The oxygenate conversion can be performed under conditions that reduce or minimize hydrogen transfer. Optionally, a catalyst that further facilitates formation of branched paraffins can be used, such as a catalyst that has some type of 12-member ring site available on the catalyst surface.

First claim

The invention claimed is:

1. A method for forming a naphtha composition, comprising:
exposing a feed comprising oxygenates and olefins to a conversion catalyst at an average reaction temperature of 230° C. to 280° C., a total pressure of 1 psig (˜7 kPa-g) to 400 psig (˜2700 kPa-g), and an oxygenate weight hourly space velocity of 0.1 hr −1 to 10.0 hr −1 , to form a converted effluent comprising a net yield of 10 wt % or more of a C 5+ fraction relative to a combined weight of the oxygenates and olefins, the C 5+ fraction comprising 15 wt % or less aromatics, relative to a weight of the C 5+ fraction, and having a research octane number (RON) of 80 or more, the feed comprising a molar ratio of oxygenates to olefins of 1 to 20,
wherein the conversion catalyst comprises 10 wt % or more of a zeolite having a MOR framework structure.

2. The method of claim 1 , wherein the C 5+ fraction comprises an RON of 85 or more.

3. A method for forming a naphtha composition, comprising:
exposing a feed comprising oxygenates and olefins to a conversion catalyst at an average reaction temperature of 230° C. to 300° C., a total pressure of 1 psig (˜7 kPa-g) to 400 psig (˜2700 kPa-g), and an oxygenate weight hourly space velocity of 0.1 hr −1 to 10.0 hr −1 , to form a converted effluent comprising a net yield of 10 wt % or more of a C 5+ fraction relative to a combined weight of the oxygenates and olefins, the C 5+ fraction comprising 15 wt % or less aromatics, relative to a weight of the C 5+ fraction, and having a research octane number (RON) of 85 or more, the feed comprising a molar ratio of oxygenates to olefins of 1 to 20,
wherein the conversion catalyst comprises 10 wt % or more of a zeolite having a framework structure of MWW, MOR, or a combination thereof.

4. The method of claim 3 , wherein the total pressure is 10 psig (70 kPa-g) to 150 psig (1050 kPa-g).

5. The method of claim 3 , wherein the conversion catalyst further comprises 0.1 wt % to 3.0 wt % of a transition metal.

6. The method of claim 3 , wherein the oxygenate comprises 90 wt % or more of methanol, dimethyl ether, or a combination thereof.

7. The method of claim 3 , wherein the conversion effluent comprises 1.0 wt % or less of compounds boiling above the naphtha boiling range.

8. The method of claim 3 , wherein the feed comprises a molar ratio of oxygenates to olefins of 1.0 to 10, or wherein the feed comprises a molar ratio of oxygenates to olefins of 4.0 to 20.

9. The method of claim 3 , wherein the feed comprising oxygenates and olefins comprises a first feedstock comprising at least a portion of the oxygenates and a second feedstock comprising at least a portion of the olefins, the first feedstock and the second feedstock being combined after entering a reactor containing the conversion catalyst.

10. The method of claim 3 , wherein the feed comprises 30 wt % to 95 wt % of oxygenates, 5 wt % to 40 wt % of olefins, or a combination thereof.

11. The method of claim 3 , wherein the feed comprises at 20 wt % to 60 wt % of components different from oxygenates and olefins.

12. The method of claim 3 , wherein the C 5+ fraction comprises 12 wt % or less aromatics relative to the weight of the C 5+ fraction.

13. The method of claim 3 , wherein the conversion catalyst comprises 10 wt % or more of MCM-49, MCM-22, MCM-56, a zeolite having a MWW framework structure, or a combination thereof, or wherein the average reaction temperature is 230° C. to 280° C., or a combination thereof.

14. The method of claim 3 , wherein the conversion catalyst comprises 10 wt % or more of a zeolite having a MOR framework structure, or wherein the average reaction temperature is 270° C. to 300° C., or a combination thereof.

Assignees

• Exxonmobil Technology & Engineering Company

Inventors

• O'Neill Brandon J
• Deimund Mark A
• Dandekar Ajit B

Classifications

• B01J29/7253

  MFS-type, e.g. ZSM-57 · CPC title

• B01J29/7038

  MWW-type, e.g. MCM-22, ERB-1, ITQ-1, PSH-3 or SSZ-25 · CPC title

• B01J29/20

  containing iron group metals, noble metals or copper · CPC title

• B01J29/7261

  MRE-type, e.g. ZSM-48 · CPC title

• B01J29/7284

  TON-type, e.g. Theta-1, ISI-1, KZ-2, NU-10 or ZSM-22 · CPC title