Liquid phase distillate dewaxing

Patent metadata

Field	Value
Publication number	US-9493718-B2
Application number	US-201113168196-A
Country	US
Kind code	B2
Filing date	Jun 24, 2011
Priority date	Jun 30, 2010
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

Hydrocarbon feeds can be hydrotreated in a continuous gas-phase environment and then dewaxed in a liquid-continuous reactor. The liquid-continuous reactor can advantageously be operated in a manner that avoids the need for a hydrogen recycle loop. A contaminant gas can be added to the hydrogen input for the liquid-continuous reactor to modify the hydrogen consumption in the reactor.

First claim

What is claimed is:

1. A method for producing a dewaxed distillate product, comprising:
contacting a feedstock having a T95 boiling point of about 440° C. or less with a hydrotreating catalyst under effective hydrotreating conditions in a hydrotreatment reactor comprising a continuous gas phase to produce a hydrotreated effluent;
separating the hydrotreated effluent into at least a hydrotreated liquid product having a cloud point and a gas-phase product comprising H 2 and H 2 S;
mixing the hydrotreated liquid product with a hydrogen-containing stream and at least a portion of the gas-phase product to produce a hydrotreated dewaxing input stream comprising an H 2 S content of about 0.1 mol % to 10 mol % of a total gas content in the hydrotreated dewaxing input; and
contacting the hydrotreated dewaxing input stream with a dewaxing catalyst under effective catalytic dewaxing conditions in a liquid-continuous reactor to form a dewaxed effluent comprising a dewaxed distillate product having a reduced level of aromatics saturation compared to a level of aromatics saturation under otherwise identical dewaxing conditions but with H 2 S content below about 0.1 mol %,
wherein the liquid-continuous reactor comprises a gas phase that is less than about 10% of the reactor volume and the dewaxed effluent has a cold flow property that is at least about 9° F. (about 5° C.) less than a corresponding cold flow property of the feedstock, and wherein the cold flow property comprises one or more of a cloud point, a pour point, and a cold filter plugging point.

2. The method of claim 1 , wherein a ratio of the hydrogen-containing stream to the at least a portion of the gas-phase product is adjusted to reduce the hydrogen consumption in the liquid-continuous reactor to about 20 Nm 3 /m 3 or less.

3. The method of claim 1 , wherein at least a portion of the dewaxed effluent from the liquid-continuous reactor is recycled and mixed with the hydrotreated liquid product prior to said mixing with the hydrogen-containing stream.

4. The method of claim 1 , wherein at least a portion of the dewaxed effluent from the liquid-continuous reactor is mixed with a second hydrogen-containing stream and recycled as an input stream to the liquid-continuous reactor.

5. The method of claim 1 , wherein the contacting in the liquid continuous reactor comprises:
removing at least a portion of the hydrotreated dewaxing input stream from the liquid-continuous reactor;
dissolving hydrogen in the removed portion; and
passing the removed portion containing the dissolved hydrogen back into the liquid-continuous reactor.

6. The method of claim 1 , wherein the effective catalytic dewaxing conditions include a temperature from about 500° F. (about 260° C.) to about 750° F. (about 399° C.), a total pressure from about 200 psig (about 1.4 MPag) to about 2250 psig (about 15.5 MPag), and an LHSV from about 0.2 hr −1 to about 15 hr −1 .

7. The method of claim 1 , wherein effective hydrotreating conditions include a temperature from about 500° F. (about 260° C.) to about 800° F. (about 425° C.), a total pressure from about 200 psig (about 1.4 MPag) to about 3000 psig (about 20.7 MPag), an LHSV from about 0.2 hr −1 to about 15 hr −1 , and a hydrogen treat gas rate from about 500 scf/bbl (about 85 Nm 3 /m 3 ) to about 10000 scf/bbl (about 1700 Nm 3 /m 3 ).

8. The method of claim 1 , wherein the dewaxing catalyst comprises a molecular sieve and a supported metal, wherein the molecular sieve comprises ZSM-5, ZSM-22, ZSM-23, ZSM-35, ZSM-48, or a combination thereof.

9. The method of claim 1 , further comprising:
separating the hydrotreated effluent into at least a hydrotreated liquid product, a first gas-phase product, and a second gas-phase product, wherein said first and second gas-phase product comprise at least H 2 and H 2 S;
providing the first gas-phase product for mixing with the hydrotreated liquid product;
recovering hydrogen from the second gas-phase product; and
recycling the recovered hydrogen.

10. The method of claim 1 , wherein the hydrotreated dewaxing input stream has an H 2 S content from about 0.5 mol % to about 10 mol % of the total gas in the hydrotreated dewaxing input stream.

11. The method of claim 1 , wherein the dewaxed effluent has an aromatics content of at least about 50% of an aromatics content of the hydrotreated effluent.

12. A method for producing a dewaxed distillate product, comprising:
providing a feedstock having a cloud point of at least about 15° F. (about −4° C.), having a T95 boiling point of about 440° C. or less, and having a first aromatics content;
contacting the feedstock with a hydrotreating catalyst under effective hydrotreating conditions in a hydrotreatment reactor comprising a continuous gas phase to produce a hydrotreated effluent;
separating the hydrotreated effluent into at least a hydrotreated liquid product and a gas-phase product comprising H 2 and H 2 S;
mixing the hydrotreated liquid product with a hydrogen containing stream and at least a portion of the gas-phase product to form a hydrotreated dewaxing input stream comprising an H 2 S content of about 0.1 mol % to 10 mol % of a total gas content in the hydrotreated dewaxing input; and
contacting the hydrotreated dewaxing input stream with a dewaxing catalyst under effective catalytic dewaxing conditions in a liquid-continuous reactor to form a dewaxed effluent comprising a dewaxed distillate product having a reduced level of aromatics saturation compared to a level of aromatics saturation under otherwise identical dewaxing conditions but with H 2 S content below about 0.1 mol %,
wherein the liquid-continuous reactor comprises a gas phase that is less than about 10% of the reactor volume, the dewaxed effluent has a second aromatics content that is at least about 50% of the first aromatics content, and the dewaxed effluent has a cloud point that is at least about 9° F. (5° C.) lower than the cloud point of the feedstock.

13. The method of claim 12 , wherein the second aromatics content is at least about 65% of the first aromatics content.

14. The method of claim 12 , wherein the effective catalytic dewaxing conditions include a temperature from about 500° F. (about 260° C.) to about 750° F. (about 399° C.), a total pressure from about 200 psig (about 1.4 MPag) to about 2250 psig (about 15.5 MPag), and an LHSV from about 0.2 hr −1 to about 15 hr −1 .

15. The method of claim 12 , wherein the effective hydrotreating conditions include a temperature from about 500° F. (about 260° C.) to about 800° F. (about 425° C.), a total pressure from about 200 psig (about 1.4 MPag) to about 3000 psig (about 20.7 MPag), an LHSV from about 0.2 hr −1 to about 15 hr −1 , and a hydrogen treat gas rate from about 500 scf/bbl (about 85 Nm 3 /m 3 ) to about 10000 scf/bbl (about 1700 Nm 3 /m 3 ).

16. The method of claim 12 , wherein the hydrotreated dewaxing input stream has an H 2 S content from about 0.5 mol % to about 10 mol % of the total gas in the hydrotreated dewaxing input stream.

17. The method of claim 12 , wherein the dewaxing catalyst comprises ZSM-23, ZSM-48, ZSM-5, or a combination thereof.

18. The method of claim 12 , further comprising:
separating the hydrotreated effluent into at least a hydrotreated liquid product, a first gas-phase product and a second gas-phase product wherein said first and second gas-phase product comprise at least H 2 and H 2 S;
providing the first gas-phase product for mixing with the hydrotreated liquid product;
recovering hydrogen from the second gas-phase product; and
rec

Assignees

• Dougherty Richard C
• Hayes Michael A
• Umansky Benjamin S
• Lewis William E
• Exxonmobil Res & Eng Co

Inventors

• Dougherty Richard C
• Hayes Michael A
• Umansky Benjamin S
• Lewis William E

Classifications

• C10G2400/04

  Diesel oil · CPC title

• C10G2300/202

  Heteroatoms content, i.e. S, N, O, P · CPC title

• C10G2300/304

  Pour point, cloud point, cold flow properties · CPC title

• Y02P30/20

  using bio-feedstock · CPC title

• C10G45/64

  containing crystalline alumino-silicates, e.g. molecular sieves · CPC title