Some content of this application is unavailable at the moment.
If this situation persist, please contact us atFeedback&Contact
1. (WO2019002803) SYSTEMS AND METHODS FOR PRODUCING LIQUID FUELS FROM LANDFILL GASES
Note: Text based on automatic Optical Character Recognition processes. Please use the PDF version for legal matters

CLAIMS:

1. A method for producing liquid fuel from landfill gas, the method comprising:

(i) providing 02, steam and landfill gas comprising 30 to 70 %vol methane and 35 to 55 %vol C02 to a single tri-reformer reactor comprising a first catalyst;

(ii) supplying energy to said single tri-reformer reactor;

(iii) performing a tri-reforming process on said landfill gas, wherein said tri- reforming process comprises carbon dioxide reforming, steam reforming, water-gas shifting, and methane oxidation, to produce synthesis gas having a H2:CO ratio of approximately 2:1 ;

(iv) providing the synthesis gas to a Fischer-Tropsch synthesis (FTS) reformer comprising a second catalyst;

(v) converting said synthesis gas into liquid fuel, fuel gas and steam within said Fischer-Tropsch synthesis reformer;

(vi) separating said liquid fuel from said fuel gas and said steam; and

(vii) combusting at least some of said fuel gas to provide at least some of said energy to said tri-reformer reactor, whereby said method for producing liquid fuel is at least partially self-sufficient in terms of energy for said tri-reforming process.

2. A method as claimed in claim 1 , wherein said landfill gas further comprises at least one of:

0.5-20 %mol nitrogen;

0.1-2.5 %mol oxygen;

1-1700 ppm hydrogen sulfide;

1-400 ppm halides;

1-10 %mol water; and

200-15,000 ppm non-methane organic compounds.

3. A method as claimed in claim 1 or 2, wherein said landfill gas is produced from municipal solid waste by biodegradation.

4. A method as claimed in any preceding claim, wherein the amount of 02 provided to said tri-reformer reactor is 1-25 %mol, based on the total moles of gases.

5. A method as claimed in any preceding claim, wherein the amount of steam provided to said tri-reformer reactor is 2-45 %mol, based on the total moles of gases.

6. A method as claimed in any preceding claim, further comprising the step of combusting landfill gas to provide energy to said single tri-reformer reactor.

7. A method as claimed in any preceding claim, wherein the majority of the energy provided to said single tri-reformer reactor is from combustion of said fuel gas.

8. A method as claimed in any preceding claim, wherein said method is substantially self-sufficient in terms of energy for said tri-reforming process.

9. A method as claimed in any preceding claim, further comprising recycling at least some of said steam from said Fischer-Tropsch reformer to said single tri-reformer reactor.

10. A method as claimed in claim 9, wherein substantially all of said steam from said Fischer-Tropsch reformer is recycled to said single tri-reformer reactor.

1 1. A method as claimed in any preceding claim, wherein the heat released in said Fischer-Tropsch synthesis is used to heat water and said heated water is recycled to said single tri-reformer reactor in the form of steam.

12. A method as claimed in any preceding claim, wherein said first catalyst comprises one or more of nickel, magnesium, cerium, and zirconium.

13. A method as claimed in any preceding claim, wherein said first catalyst comprises Ce(X)Zr(1-xryNizMg and y and z are integers and x is less than one but greater than zero.

14. A method as claimed in any preceding claim, wherein said first catalyst is

15. A method as claimed in any preceding claim, wherein said catalyst is prepared by wet impregnation.

16. A method as claimed in any preceding claim, wherein said tri-reforming process is carried out at 750-850 °C.

17. A method as claimed in any preceding claim, wherein said tri-reforming process achieves a C02 conversion of at least 27%.

18. A method as claimed in any preceding claim, wherein substantially no coke is formed.

19. A method as claimed in any preceding claim, wherein said second catalyst is a cobalt-silica catalyst.

20. A method as claimed in claim 19, wherein said catalyst is an eggshell catalyst.

21. A method for producing liquid fuel from municipal solid waste comprising:

(i) biodegrading municipal solid waste in a landfill site or biodigester to produce crude landfill gas;

(ii) separating particulate matter from said crude landfill gas to produce landfill gas; and

(iii) converting said landfill gas to liquid fuel as claimed in any one of claims 1 to 20.

22. A system for producing liquid fuel from landfill gas, the system comprising: an oxygen supply line;

a steam supply line;

a landfill gas supply line;

a fuel gas combustion unit that combusts fuel gas and provides heat to a single tri-reformer reactor;

a single tri-reformer reactor for performing a tri-reforming process on the landfill gas comprising carbon dioxide reforming, steam reforming, water-gas shifting, and methane oxidation, to produce synthesis gas having a H2:CO ratio of approximately 2:1 , wherein said tri-reformer has one or more inlets fluidly connected to said oxygen supply line, said steam supply line and said landfill gas supply line and at least one outlet for said synthesis gas;

a Fischer-Tropsch synthesis (FTS) reformer for converting the synthesis gas to liquid fuel, fuel gas and steam, wherein said FTS reformer has one or more inlets for said synthesis gas fluidly connected to said tri-reformer and an outlet for the liquid fuel, fuel gas and steam;

a separation unit for separating said liquid fuel, said fuel gas and said steam, wherein said separation unit has an inlet for the liquid fuel, fuel gas and steam fluidly connected to the Fischer-Tropsch synthesis reformer and separate outlets for each of liquid fuel, fuel gas and steam; and

a line connecting said fuel gas outlet of said separation unit to said fuel gas combustion unit.

23. The system of claim 22, further comprising a line connecting said steam outlet of said separation unit to said steam supply line.

24. The system of claim 22 or 23, wherein the tri-reformer contains a first catalyst and the FTS reformer contains a second catalyst.

25. The system of claim 24, wherein the first catalyst comprises one or more of nickel, magnesium, cerium, and zirconium.

26. The system of claim 25, wherein the first catalyst comprises Ce(x)Zr(1.X)-yNizMg and y and z are integers and x is less than one but greater than zero.

27. The system of claim 25, wherein the first catalyst comprises Ce0.6 r0.4-8 i8Mg.

28. The system of any one of claims 22 to 27, wherein the second catalyst is a cobalt-silica catalyst and preferably a promoted cobalt-silica/titiania eggshell catalyst.

29. The system of any one of claims 22 to 28, further comprising a landfill gas combustion unit that combusts landfill gas and provides heat to the tri-reformer reactor.

30. The system of any one of claims 22 to 29, further comprising a source of solar energy that provides heat to the tri-reformer reactor.

31. The system of claim 30, wherein the source of solar energy comprises heliostats and a central receiver that contains heating media that is used to provide heat to the tri-reformer reactor.

32. The system of claim 31 , further comprising a heat storage unit in which the heating media can be stored at an elevated temperature.

33. The system of any one of claims 22 to 32, further comprising a gasifier that extracts crude landfill gas from landfill biomass and provides the crude landfill gas to the tri-reformer.

34. The system of any one of claims 22 to 33, wherein the system comprises no other reactors that assist in generating the liquid fuel from the landfill gas.

35. The system of any one of claims 22 to 34, wherein said system is located on a landfill or biodigestion site.