CONVERTING BIOMASS TO DIESEL

Abstract

The present invention relates to a process and system for forming a hydrocarbon feedstock from a biomass material, and the hydrocarbon feedstock formed therefrom. The present invention also relates to a process and system for forming a bio-derived diesel fuel from a hydrocarbon feedstock, and the bio-derived diesel fuel formed therefrom, as well as intermediate treated hydrocarbon feedstocks formed during the process.

Claims

1. A process for forming a biomass derived hydrocarbon feedstock suitable for forming bio-diesel, from a biomass feedstock, comprising the steps of: a. providing a biomass feedstock; b. ensuring the moisture content of the biomass feedstock is 10% or less by weight of the biomass feedstock; c. pyrolysing the low moisture biomass feedstock at a temperature of at least 950° C. to form a mixture of biochar, hydrocarbon feedstock, non-condensable light gases, such as hydrogen, carbon monoxide, carbon dioxide and methane, and water; and d. separating the hydrocarbon feedstock from the mixture formed in step c.

2. A process according to claim 1, wherein the biomass feedstock comprises cellulose, hemicellulose or lignin-based feedstocks.

3. A process according to claim 1 or claim 2, wherein the biomass feedstock is a non-food crop biomass feedstock.

4. A process according to claim 3, wherein the non-crop biomass feedstock is selected from miscanthus, switchgrass, garden trimmings, straw, such as rice straw or wheat straw, cotton gin trash, municipal solid waste, palm fronds/empty fruit bunches (EFB), palm kernel shells, bagasse, wood, such as hickory, pine bark, Virginia pine, red oak, white oak, spruce, poplar, and cedar, grass hay, mesquite, wood flour, nylon, lint, bamboo, paper, corn stover, or a combination thereof.

5. A process according to any one of claims 1 to 4, wherein the biomass feedstock is in the form of pellets, chips, particulates or a powder.

6. A process according to claim 5, wherein the pellets, chips, particulates or powder have a diameter of from 5 μm to 10 cm, such as from 5 μm to 25 mm, preferably from 50 μm to 18 mm, more preferably from 100 μm to 10 mm.

7. A process according to claim 6, wherein the pellets, chips, particulates or powder have a diameter of at least 1 mm, such as from 1 mm to 25 mm, 1 mm to 18 mm or 1 mm to 10 mm.

8. A process according to any preceding claim, wherein initial moisture content of the biomass feedstock is up to 50% by weight of the biomass feedstock, such as up to 45% by weight of the biomass feed stock, or for example up to 30% by weight of the biomass feedstock.

9. A process according to any preceding claim, wherein the moisture content of the biomass feedstock is reduced to 7% or less by weight, such as 5% or less by weight of the biomass feedstock.

10. A process according to any preceding claim, wherein the step of ensuring the moisture content of the biomass feedstock is 10% or less by weight of the biomass feedstock comprises reducing the moisture content of the biomass feedstock

11. A process according to claim 10 wherein the moisture content of the biomass feedstock is reduced by use of a vacuum oven, a rotary dryer, a flash dryer or a heat exchanger, such as a continuous belt dryer.

12. A process according to claim 10 or 11, wherein the moisture content of the biomass feedstock is reduced through the use of indirect heating, for example by using an indirect heat belt dryer, an indirect heat fluidised bed or an indirect heat contact rotary steam-tube dryer.

13. A process according to any preceding claim, wherein the low moisture biomass feedstock is pyrolysed at temperature of at least 1000° C., more preferably at a temperature of at least 1100° C.

14. A process according to any preceding claim, wherein heat is provided to the pyrolysis step by means of convection heating, microwave heating, electrical heating or supercritical heating.

15. A process according to claim 14, wherein the heat source comprises microwave assisted heating, a heating jacket, a solid heat carrier, a tube furnace or an electric heater, preferably the heating source is a tube furnace.

16. A process according to claim 14, wherein the heat source is positioned inside the reactor.

17. A process according to claim 16, wherein the heat source comprises one or more electric spiral heaters, such as a plurality of electric spiral heaters.

18. A process according to any preceding claim, wherein the low moisture biomass is pyrolysed at atmospheric pressure.

19. A process according to any one of claims 1 to 17, wherein the low moisture biomass is pyrolysed under a pressure of from 850 to 1000 Pa, preferably from 900 to 950 Pa and, optionally, wherein the pyrolysis gases formed are separated through distillation.

20. A process according to any preceding claim, wherein the low moisture biomass feedstock is pyrolysed for a period of from 10 seconds to 2 hours, preferably, from 30 seconds to 1 hour, more preferably from 60 second to 30 minutes, such as 100 seconds to 10 minutes.

21. A process according to any preceding claim, wherein step d. comprises at least partially separating biochar from the hydrocarbon feedstock product.

22. A process according to claim 21, wherein biochar is at least partially separated from the hydrocarbon feedstock product by filtration (such as by use of a ceramic filter), centrifugation, or cyclone or gravity separation.

23. A process according to claim 21, wherein the pyrolysis reactor is arranged such that the low moisture biomass is conveyed in a counter-current direction to any pyrolysis gases formed, and optionally wherein biochar formed as a result of the pyrolysis step leaves pyrolysis reactor separate to the pyrolysis gases.

24. A process according to claim 23, wherein the pyrolysis gases are subsequently cooled, for example through the use of a venturi, to condense the hydrocarbon feedstock product.

25. A process according to any preceding claim, wherein step d. comprises at least partially separating water from the hydrocarbon feedstock product, preferably the water at least partially separated from the hydrocarbon feedstock product further comprises organic contaminants, more preferably the water at least partially separated from the hydrocarbon feedstock product is a pyroligneous acid.

26. A process according to claim 25, wherein water is at least partially separated from the hydrocarbon feedstock product by gravity oil separation, centrifugation, cyclone or microbubble separation.

27. A process according to any preceding claim, wherein step d. comprises at least partially separating non-condensable light gases from the hydrocarbon feedstock product.

28. A process according to claim 27, wherein non-condensable light gases are at least partially separated from the hydrocarbon feedstock product by use of flash distillation or fractional distillation.

29. A process according to claim 27 or 28, wherein the separated non-condensable light gases are recycled and optionally combined with the low moisture biomass feedstock in step c.

30. A process according to any preceding claim, further comprising the step of filtering the hydrocarbon feedstock product to at least partially remove contaminants, such as carbon, graphene, polyaromatic compounds and/or tar, contained therein.

31. A process according to claim 30, wherein the filtration step comprises the use of a membrane filter to remove larger contaminants.

32. A process according to claim 30 or 31, wherein the filtration step comprises fine filtration to remove smaller contaminants, for example by using a Nutsche filter.

33. A process according to any one of claims 30 to 32, wherein the filtration step comprises contacting the hydrocarbon feedstock product with an active carbon compound and/or a crosslinked organic hydrocarbon resin and subsequently separating the hydrocarbon feedstock product from the active carbon and/or crosslinked organic hydrocarbon resin compound though filtration.

34. A process according to claim 33, wherein the active carbon compound and/or crosslinked organic hydrocarbon resin is contacted with the hydrocarbon feedstock product under ambient conditions; and/or wherein the active carbon compound and/or crosslinked organic hydrocarbon resin is contacted with the hydrocarbon feedstock product for at least 15 minutes before separation, preferably at least 20 minutes, more preferably at least 25 minutes; and/or wherein the step of filtering the hydrocarbon feedstock is performed once or is repeated one or more times.

35. A process according to any one of claims 30 to 34, wherein the tar removed from the hydrocarbon feedstock is recycled and optionally combined with the low moisture biomass feedstock in step c.

36. A biomass derived hydrocarbon feedstock obtainable by the process according to any one of claims 1 to 35.

37. A hydrocarbon feedstock according to claim 36, wherein the hydrocarbon feedstock comprises at least 0.1% by weight of one or more C.sub.8 compounds, at least 0.5% by weight of one or more C.sub.10 compounds, at least 5% by weight of one or more C.sub.12 compounds, at least 5% by weight of one or more C.sub.16 compounds and at least 30% by weight of at least one or more C.sub.18 compounds.

38. A hydrocarbon feedstock according to claim 37, wherein the hydrocarbon feedstock comprises at least 0.5% by weight of one or more C.sub.8 compounds, at least 2% by weight of one or more C.sub.10 compounds, at least 6% by weight of one or more C.sub.12 compounds; at least 6% by weight of one or more C.sub.16 compounds and/or at least 33% by weight of one or more C.sub.18 compounds.

39. A hydrocarbon feedstock according to any one of claims 36 to 38, wherein the hydrocarbon feedstock has a pour point of −10° C. or less, preferably −15° C. or less, such as −16° C. or less.

40. A hydrocarbon feedstock according to any one of claims 36 to 39, wherein the hydrocarbon feedstock comprises 70 ppmw or less of sulphur.

41. A process of forming a bio-derived diesel fuel, comprising the steps of: A. providing a biomass derived hydrocarbon feedstock comprising at least 0.1% by weight of one or more C.sub.8 compounds, at least 0.5% by weight of one or more C.sub.10 compounds, at least 5% by weight of one or more C.sub.12 compounds, at least 5% by weight of one or more C.sub.16 compounds and at least 30% by weight of one or more C.sub.18 compounds; B. processing the hydrocarbon feedstock to produce a refined bio-oil, wherein the process comprises the steps of: i. at least partially removing sulphur containing components from the hydrocarbon feedstock; ii. hydro-treating the hydrocarbon feedstock; and iii. hydro-isomerising the hydrocarbon feedstock; and C. fractionating the resulting refined bio-oil to obtain a bio-derived diesel fuel fraction.

42. A process according to claim 41, wherein the hydrocarbon feedstock comprises at least 0.5% by weight of one or more C.sub.8 compounds, at least 2% by weight of one or more C.sub.10 compounds, at least 6% by weight of one or more C.sub.12 compounds, at least 6% by weight of one or more C.sub.16 compounds and at least 33% by weight of one or more C.sub.18 compounds.

43. A process according to claim 41 or 42, wherein the sulphur removal step comprises a catalytic hydro-desulphurisation step.

44. A process according to claim 43, wherein the catalyst is part of a fixed bed or a trickle bed reactor.

45. A process according to claim 43 or 44, wherein the catalyst is selected from a nickel molybdenum sulphide (NiMoS), molybdenum, molybdenum disulphide (MoS.sub.2), cobalt/molybdenum, cobalt molybdenum sulphide (CoMoS) and/or a nickel/molybdenum based catalyst, and preferably wherein the catalyst is selected from a nickel molybdenum sulphide (NiMoS) based catalyst.

46. A process according to any one of claims 43 to 45, wherein the catalyst is a supported catalyst, such as by means of a support selected from activated carbon, silica, alumina, silica-alumina, a molecular sieve, and/or a zeolite.

47. A process according to any one of claims 43 to 46, wherein the hydro-desulphurisation step is performed at a temperature of from 250° C. to 400° C., preferably from 300° C. and 350° C.; and/or wherein the hydro-desulphurisation step is performed at a reaction pressure of from 4 to 6 MPaG, preferably from 4.5 to 5.5 MPaG, more preferably a bout 5 MPaG.

48. A process according to any one of claims 41 to 47, wherein the desulphurised hydrocarbon feedstock comprises at least 0.5% by weight of one or more C.sub.8 compounds, at least 2% by weight of one or more C.sub.10 compounds, at least 4% by weight of one or more C.sub.12 compounds, at least 10% by weight of one or more C.sub.16 compounds and at least 25% by weight of one or more C.sub.18 compounds.

49. A process according to claim 48, wherein the desulphurised hydrocarbon feedstock comprises at least 1% by weight of one or more C.sub.8 compounds, at least 3% by weight of one or more C.sub.10 compounds, at least 5% by weight of one or more C.sub.12 compounds, at least 12% by weight of one or more C.sub.16 compounds and/or at least 27% by weight of one or more C.sub.18 compounds.

50. A process according to any one of claims 41 to 49, wherein the catalytic hydro-desulphurisation process further comprises the step of degassing the reduced sulphur hydrocarbon feedstock to remove hydrogen disulphide gas, such as by cooling the reduced sulphur hydrocarbon feedstock to a temperature of from 60 to 120° C., preferably from 80 to 100° C. and optionally applying a vacuum pressure of less than 6 KPaA, preferably less than 5 KPaA, more preferably less than 4 KPaA.

51. A process according to claim 50, wherein the degassing step removes hydrogen formed during the catalytic hydro-desulphurisation process, and optionally wherein the hydrogen is recycled to the hydrocarbon feedstock of step A.

52. A process according to any one of claims 41 to 51, wherein the hydro-treating step is performed at a temperature of from 250° C. to 350° C., preferably from 270° C. to 330° C., more preferably from 280° C. to 320° C.; and/or wherein the hydro-treating step is performed at a reaction pressure of from 4 MPaG to 6 MPaG, preferably from 4.5 MPaG to 5.5 MPaG, more preferably about 5 MPaG.

53. A process according to any one of claims 41 to 52, wherein the hydro-treating process further comprises a catalyst, such as a catalyst as part of a fixed bed or a trickle bed reactor.

54. A process according to claim 53, wherein the catalyst comprises a metal selected from Group IIIB, Group IVB, Group VB, Group VIB, Group VIIB, and Group VIII, of the periodic table.

55. A process according to claim 54, wherein the catalyst comprises a metal selected from Group VIII of the periodic table, preferably the catalyst comprises Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, and/or Pt, such as a catalyst comprising Ni, Co, Mo, W, Cu, Pd, Ru, Pt, and preferably wherein the catalyst is selected from CoMo, NiMo or Ni.

56. A process according to any one of claims 53 to 55, wherein the catalyst is a supported catalyst, such as by means of a support selected from activated carbon, silica, alumina, silica-alumina, a molecular sieve, and or a zeolite.

57. A process according to any one of claims 41 to 56, wherein the hydro-treated hydrocarbon feedstock comprises at least 0.5% by weight of one or more C.sub.8 compounds, at least 6% by weight of one or more C.sub.10 compounds, at least 4% by weight of one or more C.sub.12 compounds, at least 3% by weight of one or more C.sub.16 compounds and at least 30% by weight of one or more C.sub.18 compounds.

58. A process according to claim 57, wherein the hydro-treated hydrocarbon feedstock comprises at least 1% by weight of one or more C.sub.8 compounds, at least 7% by weight of one or more C.sub.10 compounds, at least 5% by weight of one or more C.sub.12 compounds, at least 4% by weight of one or more C.sub.16 compounds and/or at least 35% by weight of one or more C.sub.18 compounds.

59. A process according to any one of claims 41 to 58, wherein the hydro-isomerisation step is performed at a temperature of from 260° C. to 370° C., preferably from 290° C. to 350° C., more preferably from 310° C. to 330° C.; and/or wherein the hydro-isomerisation step is performed at a reaction pressure of from 4 MPaG to 6 MPaG, preferably from 4.5 MPaG to 5.5 MPaG, more preferably about 5 MPaG.

60. A process according to any one of claims 41 to 59, wherein the hydro-isomerisation step further comprises a catalyst, such as catalyst as part of a fixed bed or a trickle bed reactor.

61. A process according to claim 60, wherein the catalyst comprises a metal selected from Group VIII of the periodic table, such as a catalyst selected from a platinum and/or palladium catalyst, and optionally wherein the catalyst is a supported catalyst, such as by means of a support selected from activated carbon, silica, alumina, silica-alumina, a molecular sieve, and or a zeolite.

62. A process according to any one of claims 41 to 61, wherein the hydro-isomerised hydrocarbon feedstock comprises at least 0.5% by weight of one or more C.sub.8 compounds, at least 7.5% by weight of one or more C.sub.10 compounds, at least 4% by weight of one or more C.sub.12 compounds, at least 7% by weight of one or more C.sub.16 compounds and at least 12% by weight of one or more C.sub.18 compounds.

63. A process according to claim 62, wherein the hydro-isomerised hydrocarbon feedstock comprises at least 1% by weight of one or more C.sub.8 compounds, at least 10% by weight of one or more C.sub.10 compounds, at least 5% by weight of one or more C.sub.12 compounds, at least 8% by weight of one or more C.sub.16 compounds and/or at least 15% by weight of one or more C.sub.18 compounds.

64. A process according to any one of claims 41 to 63, wherein hydro-isomerisation process further comprises the step of degassing the hydro-isomerised hydrocarbon feedstock to remove light gases, such as hydrogen, methane, ethane and propane gas present, and optionally wherein the light gases are recycled to the hydrocarbon feedstock of step A.

65. A process according to any one of claims 41 to 64, wherein the hydro-isomerisation process further comprises the step of hydro-stabilising the hydro-isomerised hydrocarbon feedstock.

66. A process according to claim 65, wherein the hydro-stabilisation reaction is performed at a temperature of from 250° C. to 350° C., preferably from 260° C. to 340° C., more preferably from 280° C. to 320° C. and/or wherein the hydro-stabilisation process is performed at a reaction pressure of from 4 MPaG to 6 MPaG, preferably from 4.5 MPaG to 5.5 MPaG, more preferably about 5 MPaG.

67. A process according to claim 65 or 66, wherein the hydro-stabilisation reaction further comprises a catalyst, such as a catalyst as part of a fixed bed or a trickle bed reactor.

68. A process according to claim 67, wherein the catalyst is selected from a Ni, Pt and/or Pd-based catalyst.

69. A process according to claim 67 or 68, wherein the catalyst is a supported catalyst, such as by means of a support selected from activated carbon, silica, alumina, silica-alumina, a molecular sieve, and or a zeolite.

70. A process according to any one of claims 41 to 69, wherein the fractionation step comprises separating a first fractionation cut having a cut point of between 110° C. and 170° C., preferably between 130° C. and 160° C., more preferably 150° C. of the refined bio-oil under atmospheric pressure.

71. A process according to claim 70, wherein the method comprises forming a second fractionation cut of the refined bio-oil, with a cut point between 280° C. and 320° C., preferably from 290° C. to 310° C., more preferably about 300° C., wherein the bottom stream is collected as a bio-derived diesel fuel.

72. A process according to claim 71, wherein the bottom stream comprises from 10 to 30% by weight of the refined bio-oil, preferably from 15 to 25% by weight of the refined bio-oil.

73. A process according to any one of claims 41 to 72 wherein the hydrocarbon feedstock of step A. is produced by the process according to any one of claims 1 to 35.

74. A desulphurised hydrocarbon feedstock, obtainable by the process of any one of claims 41 to 51, wherein the feedstock comprises at least 0.5% by weight of one or more C.sub.8 compounds, at least 2% by weight of one or more C.sub.10 compounds, at least 4% by weight of one or more C.sub.12 compounds, at least 10% by weight of one or more C.sub.16 compounds and at least 25% by weight of one or more C.sub.18 compounds.

75. A desulphurised hydrocarbon feedstock according to claim 74, wherein the feedstock comprises at least 1% by weight of one or more C.sub.8 compounds, at least 3% by weight of one or more C.sub.10 compounds, at least 5% by weight of one or more C.sub.12 compounds, at least 12% by weight of one or more C.sub.16 compounds and/or at least 27% by weight of one or more C.sub.18 compounds.

76. A hydro-treated hydrocarbon feedstock, obtainable by the process of any one of claims 41 to 58, wherein the feedstock comprises at least 0.5% by weight of one or more C.sub.8 compounds, at least 6% by weight of one or more C.sub.10 compounds, at least 4% by weight of one or more C.sub.12 compounds, at least 3% by weight of one or more C.sub.16 compounds and at least 30% by weight of one or more C.sub.18 compounds.

77. A hydro-treated hydrocarbon feedstock according to claim 76, wherein the feedstock comprises at least 1% by weight of one or more C.sub.8 compounds, at least 7% by weight of one or more C.sub.10 compounds, at least 5% by weight of one or more C.sub.12 compounds, at least 4% by weight of one or more C.sub.16 compounds and/or at least 35% by weight of one or more C.sub.18 compounds.

78. A hydro-isomerised hydrocarbon feedstock, obtainable by the process according to any one of claims 41 to 65, wherein the feedstock comprises at least 0.5% by weight of one or more C.sub.8 compounds, at least 7.5% by weight of one or more C.sub.10 compounds, at least 4% by weight of one or more C.sub.12 compounds, at least 7% by weight of one or more C.sub.16 compounds and at least 12% by weight of one or more C.sub.18 compounds.

79. A hydro-isomerised hydrocarbon feedstock according to claim 78, wherein the feedstock comprises at least 1% by weight of one or more C.sub.8 compounds, at least 10% by weight of one or more C.sub.10 compounds, at least 5% by weight of one or more C.sub.12 compounds, at least 8% by weight of one or more C.sub.16 compounds and/or at least 15% by weight of one or more C.sub.18 compounds.

80. A refined bio-oil, obtainable by a process according to any one of claims 41 to 69, wherein the refined bio-oil formed comprises at least 7.5% by weight of one or more C.sub.10 compounds, at least 4% by weight of one or more C.sub.12 compounds, at least 7% by weight of one or more C.sub.16 compounds and at least 12% by weight of one or more C.sub.18 compounds.

81. A refined bio-oil according to claim 80, wherein the refined bio-oil comprises at least 10% by weight of one or more C.sub.10 compounds, at least 5% by weight of one or more C.sub.12 compounds, at least 8% by weight of one or more C.sub.16 compounds and/or at least 15% by weight of one or more C.sub.18 compounds.

82. A refined bio-oil according to claim 80 or 81, wherein the refined bio-oil has a pour point of −45° C. or less, preferably −50° C. or less, more preferably −54° C. or less.

83. A bio-derived diesel fuel formed by a process according to anyone of claims 41 to 73.

84. A bio-derived diesel fuel according to claim 83, wherein the bio-derived diesel fuel is formed entirely from a biomass feedstock.

85. A bio-derived diesel fuel according to claim 83 or 84, wherein the bio-derived diesel fuel comprises at least 0.25% by weight of one or more C.sub.15 compounds, at least 5% by weight of one or more C.sub.16 compounds, at least 24% by weight of one or more C.sub.17 compounds and/or at least 45% by weight of one or more C.sub.18 compounds.

86. A bio-derived diesel fuel according to claim 85, wherein the bio-derived diesel fuel comprises at least 0.5% by weight of one or more C.sub.15 compounds, at least 6.5% by weight of one or more C.sub.16 compounds, at least 26% by weight of one or more C.sub.17 compounds and/or at least 50% by weight of one or more C.sub.18 compounds.

87. A bio-derived diesel fuel according to claim 83 or 86, wherein the bio-derived diesel fuel exceeds the Euro 5 and Euro 6 standards for diesel fuel.

88. A bio-derived diesel fuel according to any one of claims 83 to 87, wherein the bio-derived diesel fuel has a cetane number of at least 60, preferably a cetane number of at least 65, more preferably a cetane number of at least 70.

89. A bio-derived diesel fuel according to any one of claims 83 to 88, wherein the pour point of the bio-derived diesel fuel is −40° C. or less, preferably −42° C. or less, more preferably −45° C. or less.

90. A bio-derived diesel fuel according to any one of claims 83 to 89, wherein the bio-derived diesel fuel comprises 10 ppmw or less of sulphur, preferably 5 ppmw or less of sulphur, more preferably 1 ppmw or less of sulphur.

91. A bio-derived diesel fuel according to any one of claims 83 to 90, wherein the bio-derived diesel fuel has at least the following properties: a. a cetane number of at least 65, more preferably a cetane number of at least 70; b. 10 ppmw or less of sulphur, preferably 5 ppmw or less of sulphur, more preferably 1 ppmw or less of sulphur; and c. a pour point of fuel is −40° C. or less, preferably −42° C. or less, more preferably −45° C. or less.

Description

[0210] The present inventions will now be described with reference to the following non limiting examples, and with reference to the accompanying drawings, in which:

[0211] FIG. 1 illustrates the carbon number distribution of a filtered hydrocarbon feedstock and a reduced sulphur hydrocarbon feedstock formed in accordance with the present invention;

[0212] FIG. 2 illustrates the carbon number distribution of a hydro-treated hydrocarbon feedstock and a refined bio-oil following an isomerisation process formed in accordance with the present invention; and

[0213] FIG. 3 illustrates the carbon number distribution of the bio-derived naphtha, jet fuel and diesel formed.

EXAMPLES

[0214] Forming a Bio-Derived Diesel Fuel from a Hydrocarbon Feedstock

Example 1—Filtering a Bio-Derived Hydrocarbon Feedstock

[0215] A bio-derived hydrocarbon feedstock was formed in accordance with the disclosure of the present invention. The hydrocarbon feedstock mainly comprised hydrocarbon compounds but also comprised minor amounts of contaminants such as ta r of various sizes, sulphur containing compound, ammonia containing compounds, halogen derivatives, oxygenates and water. The pour point of the feedstock was measured as approximately −17° C., the sulphur content was measured as approximately 67 ppmw and the bromine content was measured as 7×10.sup.3 mgBr/100 ml.

[0216] The hydrocarbon feedstock was filtered under the following conditions in accordance with the present invention.

[0217] The hydrocarbon feedstock was contacted with an active carbon powder under ambient conditions for at least 10 minutes. The hydrocarbon feedstock was subsequently separated from the active carbon powder through filtration. The process of contacting the hydrocarbon feedstock with an active carbon powder and separating the hydrocarbon feedstock was then repeated.

[0218] The resulting hydrocarbon feedstock showed that the levels of heavy tars and some harmful species, such as nitrogen-containing compounds, had been reduced to an acceptable level in accordance with the requirements of an Euro 6 standard diesel fuel, as set out in Table 1 above.

Example 2—Hydro-Desulphurisation of a Filtered Hydrocarbon Feedstock

[0219] The filtered hydrocarbon feedstock was reacted with hydrogen gas at a temperature of from 300 and 350° C., under a reaction pressure of 5 MPaG and wherein the recirculating hydrogen gas to hydrocarbon feedstock ratio was 500 to 1,000 NV/NV. The liquid space velocity of the reaction was maintained at 0.5-2 V/V/hr and the H.sub.2S concentration was maintained at a level of 150 to 250 ppmV. The hydro-desulphurisation reaction was catalysed using a NiMoS catalyst supported on a porous Al.sub.2O.sub.3 substrate.

[0220] Following the hydro-desulphurisation reaction the resulting hydrocarbon feedstock was cooled and first flashed at ambient temperature. The hydrocarbon feedstock was subsequently heated to a temperature of 80 to 100° C. and degassed at a vacuum pressure of less than 5 KPaA to remove trace amounts of H.sub.2S present.

[0221] The sulphur content of the de-sulphurised hydrocarbon was significantly reduced and was below the measurable detection limit (˜1 ppmw). The bromine index of the de-sulphurised hydrocarbon feedstock was reduced to about half of the filtered hydrocarbon feedstock, approximately 4×10.sup.3 mgBr/100 ml. The pour point of the de-sulphurised hydrocarbon feedstock was significantly improved and was reduced to −35° C. No significant cracking occurred as a result of the de-sulphurisation process, as illustrated in FIG. 1.

Example 3—Hydro-Treatment of the De-Sulphurised Hydrocarbon Feedstock

[0222] Hydro-treatment of the de-sulphurised hydrocarbon feedstock was performed at a reaction temperature of from 280 to 320° C. and a reaction pressure of approximately 5 MPaG, wherein the recirculated hydrogen gas to de-sulphurised hydrocarbon feedstock ratio was from 500 to 1,000 NV/NV and a liquid space velocity was from 1 to 1.5 V/V/hr. The hydro-treatment was performed in a trickle bed reactor. A Ni catalyst supported on a porous Al.sub.2O.sub.3 substrate was used to catalyse the hydro-treatment step.

[0223] The carbon number distribution of the hydro-treated hydrocarbon feedstock is illustrated in FIG. 2. The bromine index of the hydro-treated hydrocarbon feedstock was, again, significantly reduced compared to the hydro-desulphurised hydrocarbon feedstock to approximately 10 mgBr/100 ml. The pour point of the de-sulphurised hydrocarbon feedstock was maintained at −35° C.

Example 4—Hydro-Isomerising the Hydro-Treated Hydrocarbon Feedstock

[0224] The hydro-isomerisation reaction was performed at a reaction temperature of from 310 to 330° C. and a reaction pressure of approximately 5 MPaG, with a recirculating hydrogen gas to hydrocarbon feed ratio of 500 to 1,000 NV/NV and a liquid space velocity of 0.5 to 1 V/V/hr. The reaction was performed on a trickle bed reactor using a supported Pt/Pd catalyst.

[0225] The hydro-isomerised hydrocarbon feedstock was subsequent processed using a hydro-stabilisation treatment. The hydro-stabilisation treatment was performed at a reaction temperature of from 280 to 320° C. and a reaction pressure of approximately 5 MPaG, with a recirculating hydrogen gas to hydrocarbon feed ratio of 500 to 1,000 NV/NV and a liquid space velocity of 1 to 1.5 V/V/hr. The hydro-stabilisation process was performed using a trickle bed reactor and a Ni catalyst supported on a porous Al.sub.2O.sub.3 substrate.

[0226] The carbon number distribution of the refined bio-oil formed is illustrated in FIG. 2. The bromine index of the resulting refined bio-oil was below the measureable detection limit. The pour point of the hydro-stabilised refined bio-oil was further reduced to below −54° C.

[0227] As a result of the refining process, a small amount (<5 wt %) of liquid petroleum gas (LPG) was also formed.

Example 5—Fractionating the Refined Bio-Oil to Obtain a Bio-Derived Diesel Fuel

[0228] The refined bio-oil was first fractionated using a distillation tower under ambient pressure with a cut point of 150° C. Approximately 20 wt % of the refined bio-oil was separated as naphtha from the stream from the top of the distillation tower.

[0229] The stream removed from the bottom of the distillation tower was further fractionated under vacuum with a cut point of 300° C. The stream collected from the top of the distillation tower was A1 grade jet fuel, accounting for approximately 50 wt % of the refined bio-oil. The stream collected from the bottom of the distillation tower was a bio-derived diesel fuel.