Enhancement of Fischer-Tropsch process for hydrocarbon fuel formulation in a GTL environment

• US 9,212,319 B2
• Filed: 05/05/2013
• Issued: 12/15/2015
• Est. Priority Date: 05/09/2012
• Status: Active Grant

• Current Assignee: Expander Energy Inc.
• Original Assignee: Expander Energy Inc.
• Inventors: Kresnyak, Steve
• Primary Examiner(s): Parsa, Jafar
• Assistant Examiner(s): BAHTA, MEDHANIT W
• Application Number:
  US13/887,342
• Publication Number:
  US 20140206780A1
• Time in Patent Office: 954 Days
• US Class Current: 1/1
• CPC Class Codes: C01B 2203/0233 the reforming step being a steam reforming step
• CPC Class Codes: C01B 2203/0244 the reforming step being an autothermal reforming step, e.g. secondary reforming processes
• CPC Class Codes: C01B 2203/062 Hydrocarbon production, e.g. Fischer-Tropsch process
• CPC Class Codes: C01B 2203/1241 Natural gas or methane
• CPC Class Codes: C01B 2203/148 involving a recycle stream to the feed of the process for making hydrogen or synthesis gas
• CPC Class Codes: C01B 3/38 using catalysts
• CPC Class Codes: C10G 2/30 from carbon monoxide with hydrogen
• CPC Class Codes: C10G 2/33 characterised by the catalyst used
• CPC Class Codes: C10G 2300/1025 Natural gas
• CPC Class Codes: C10G 2300/4081 Recycling aspects
• CPC Class Codes: C10G 2300/42 Hydrogen of special source or of special composition
• CPC Class Codes: C10G 2400/04 Diesel oil
• CPC Class Codes: C10G 2400/08 Jet fuel
• CPC Class Codes: C10L 1/04 essentially based on blends of hydrocarbons
• CPC Class Codes: C10L 1/08 for compression ignition
• CPC Class Codes: C10L 3/10 Working-up natural gas or synthetic natural gas
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel
• CPC Class Codes: Y02P 20/52 using catalysts, e.g. selective catalysts

Abstract

An enhanced natural gas processing method using Fischer-Tropsch (FT) process for the synthesis of sulfur free, clean burning, hydrocarbon fuels, examples of which include syndiesel and aviation fuel. A selection of natural gas, separately or combined with portions of natural gas liquids and FT naphtha and FT vapors are destroyed in a syngas generator and used or recycled as feedstock to an Fischer-Tropsch (FT) reactor in order to enhance the production of syndiesel from the reactor. The process enhancement results is the maximum production of formulated syndiesel without the presence or formation of low value by-products.

Claims

1. A method for converting natural gas byproducts to synthetic fuel, comprising:

providing a source of natural gas;

extracting byproducts comprising ethane, propane, butane, pentane plus or mixtures thereof from said natural gas, wherein said byproducts are free of methane;

feeding at least a portion of one or more of said byproducts to a steam methane reformer to directly produce a hydrogen rich syngas stream; and

catalytically converting said syngas to said synthetic fuel in a fuel synthesis circuit including a Fischer Tropsch reactor.

2. The method as set forth in claim 1, wherein said natural gas is processed to generate a gas phase and a hydrocarbon liquid phase from said natural gas.

3. The method as set forth in claim 2, further including the step of fractioning said hydrocarbon liquid phase to separate methane, and said ethane, propane, butane, pentane plus or mixtures thereof in a predetermined amount.

4. The method as set forth in claim 3, wherein said ethane is removed from said feedstock prior to introduction of said feedstock into said fuel synthesis circuit.

5. The method as set forth in claim 3, wherein said propane is removed from said feedstock prior to introduction of said feedstock into said fuel synthesis circuit.

6. The method as set forth in claim 3, wherein said butane is removed from said feedstock prior to introduction of said feedstock into said fuel synthesis circuit.

7. The method as set forth in claim 1, wherein said synthetic fuel is synthetic diesel.

8. The method as set forth in claim 1, wherein said synthetic fuel is synthetic jet fuel.

9. The method as set forth in claim 1, wherein said fuel synthesis circuit comprises a gas to liquids (GTL) plant.

10. The method as set forth in claim 1, wherein said natural gas is pretreated prior to extraction to remove pentane and higher alkanes.

11. The method as set forth in claim 1, which comprises feeding said ethane as said feedstock.

12. The method as set forth in claim 1, which comprises feeding said propane as said feedstock.

13. The method as set forth in claim 1, which comprises feeding said butane as said feedstock.

14. The method as set forth in claim 1, which comprises feeding a mixture of said propane and butane as said feedstock.

15. The method of claim 1, wherein the hydrogen to carbon monoxide ratio is greater than 3:

1.

16. The method of claim 15, wherein the hydrogen to carbon monoxide ratio is from 3:

1 to 5;

1.

17. A method for preparing synthetic hydrocarbons, comprising the steps of:

providing a source of natural gas;

extracting byproducts comprising ethane, propane, butane, pentane plus or mixtures thereof from said natural gas, wherein said byproducts are free of methane;

feeding at least a portion of one or more of said byproducts to a steam methane reformer to directly produce a hydrogen rich syngas stream;

catalytically converting said hydrogen rich syngas stream in a Fischer Tropsch reactor to produce said synthetic hydrocarbons, containing at least naphtha;

recycling at least a portion of said naphtha to said syngas generator to form an enhanced hydrogen rich syngas stream; and

re-circulating said enhanced hydrogen rich syngas stream for conversion to enhance the formulation of synthetic hydrocarbons.

18. The method a set forth in claim 17, wherein said synthetic hydrocarbons include synthetic diesel.

19. The method as set forth in claim 17, wherein said synthetic hydrocarbons include synthetic jet fuel.

20. The method of claim 17, wherein the hydrogen to carbon monoxide ratio is greater than 3:

1.

21. The method of claim 20, wherein the hydrogen to carbon monoxide ratio is from 3:

1 to 5;

1.

22. A method of preparing synthetic hydrocarbons, comprising the steps of:

providing a source of natural gas;

extracting byproducts comprising ethane, propane, butane, pentane plus or mixtures thereof from said natural gas, wherein said byproducts are free of methane;

feeding at least a portion of one or more of said byproducts to a steam methane reformer to directly produce a hydrogen rich syngas stream;

catalytically converting said rich syngas stream in a Fischer Tropsch reactor to produce synthetic hydrocarbons, containing at least naphtha and unconverted FT (Fischer-Tropsch) vapours;

recycling at least a portion of said naphtha and unconverted FT vapours to said syngas generator to form an enhanced hydrogen rich syngas stream; and

re-circulating said enhanced hydrogen rich stream for conversion to enhance the formulation of synthetic hydrocarbons.

23. The method a set forth in claim 22, wherein said synthetic hydrocarbons include synthetic diesel.

24. The method as set forth in claim 22, wherein said synthetic hydrocarbons include synthetic jet fuel.

25. The method of claim 22, wherein the hydrogen to carbon monoxide ratio is greater than 3:

1.

26. The method of claim 25, wherein the hydrogen to carbon monoxide ratio is from 3:

1 to 5;

1.