Renewable jet fuel blendstock from isobutanol

• US 8,373,012 B2
• Filed: 05/09/2011
• Issued: 02/12/2013
• Est. Priority Date: 05/07/2010
• Status: Expired due to Fees

• Current Assignee: Gevo Incorporated
• Original Assignee: Gevo Incorporated
• Inventors: Peters, Matthew W., Taylor, Joshua D.
• Primary Examiner(s): Dang, Thuan D
• Application Number:
  US13/103,812
• Publication Number:
  US 20110288352A1
• Time in Patent Office: 645 Days
• Field of Search: 585/14, 585/240, 585/254, 585/303, 585/310, 585/324, 585/640, 585/643, 585/647, 443/85, 443/98, 444/03, 444/37
• US Class Current: 585/310
• CPC Class Codes: C10G 2300/1014 of vegetal origin
• CPC Class Codes: C10G 2300/1051 Kerosene having a boiling range of about 180 - 230 °C
• CPC Class Codes: C10G 2400/08 Jet fuel
• CPC Class Codes: C10G 3/42 Catalytic treatment
• CPC Class Codes: C10G 3/44 characterised by the catalyst used
• CPC Class Codes: C10G 50/00 Production of liquid hydrocarbon mixtures from lower carbon number hydrocarbons, e.g. by oligomerisation
• CPC Class Codes: C10G 69/126 polymerisation, e.g. oligomerisation
• CPC Class Codes: C10L 1/04 essentially based on blends of hydrocarbons
• CPC Class Codes: Y02P 30/20 using bio-feedstock

Abstract

The present invention in its various embodiments is directed to methods for preparing a renewable jet fuel blendstock, and blendstocks prepared by such methods, comprising fermenting a biomass-derived feedstock to form one or more C₂-C₆ alcohols such as isobutanol, catalytically dehydrate and oligomerize the alcohols to form higher molecular weight olefins (e.g., C₈-C₁₆ olefins), hydrogenating at least a portion of the higher molecular weight olefins to form a renewable jet fuel blendstock comprising C₁₂ and C₁₆ alkanes which meet or exceed the requirements of ASTM D7566-10a for hydroprocessed synthesized paraffinic kerosene (SPK).

Claims

1. A process for preparing renewable jet fuel blendstock comprising:

(a) treating biomass to form a feedstock;

(b) fermenting the feedstock with one or more species of microorganism, thereby forming isobutanol;

(c) dehydrating at least a portion of the isobutanol obtained in step (b), thereby forming a dehydration product comprising isobutene;

(d) oligomerizing at least a portion of the dehydration product, thereby forming a product comprising one or more C₈, one or more C₁₂, and one or more C₁₆ unsaturated oligomers; and

(e) hydrogenating at least a portion of the product of step (d) in the presence of hydrogen, thereby forming a renewable jet fuel blendstock comprising one or more C₁₂ and one or more C₁₆ saturated alkanes;

(f) adjusting the ratio of C₁₂ and C₁₆ saturated alkanes provided by step (e) to form a renewable jet fuel blendstock which meets or exceeds the requirements of ASTM D7566-10a for hydroprocessed synthesized paraffinic kerosene (SPK).

2. The process of claim 1, wherein said dehydrating is carried out in the presence of a dehydration catalyst, said oligomerizing is carried out in the presence of an oligomerization catalyst, and said hydrogenating is carried out in the presence of a hydrogenation catalyst.

3. The process of claim 2, wherein each of said dehydrating, oligomerizing, and hydrogenating are carried out in a different reaction zone.

4. The process of claim 2, wherein two or more of said dehydrating, oligomerizing, and hydrogenating are carried out in the same reaction zone.

5. The process of claim 2, wherein one or more of the dehydration catalyst, oligomerization catalyst, or hydrogenation catalyst are heterogeneous catalysts.

6. The process of claim 2, wherein one or more of the dehydration catalyst, oligomerization catalyst, or hydrogenation catalyst are homogeneous catalysts.

7. The process of claim 1, wherein said dehydrating and/or said oligomerizing are carried out in the presence of an acidic catalyst, wherein the acidic catalyst for dehydrating and the acidic catalyst for oligomerizing is the same or different.

8. The process of claim 7, wherein said acidic catalyst for dehydrating and said acidic catalyst for oligomerizing are each independently selected from the group consisting of inorganic acids, organic sulfonic acids, heteropolyacids, perfluoroalkyl sulfonic acids, metal salts thereof, mixtures of metal salts, and combinations thereof.

9. The process of claim 8, wherein said acid catalyst for oligomerizing is Amberlyst-35.

10. The process of claim 1, wherein said hydrogenating is carried out in the presence of a hydrogenation catalyst selected from the group consisting of iridium, platinum, palladium, rhodium, nickel, ruthenium, rhenium and cobalt;

compounds thereof; and

combinations thereof.

11. The process of claim 1, further comprising removing said isobutanol from the feedstock before said dehydrating.

12. The process of claim 11, wherein said removing comprises carrying out said fermenting in step (b) below atmospheric pressure, whereby aqueous isobutanol vapor is removed.

13. The process of claim 1, further comprising:

a. separating at least a portion of said product comprising one or more C₁₂ and one or more C₁₆ unsaturated oligomers produced in step (d); and

b. combining the separated portion with the dehydration product of step (c) prior to said oligomerization step

c. adjusting the ratio of C₁₂ and C₁₆ saturated alkanes provided by step (e) by recycling at least a portion of the C₈ unsaturated oligomers formed in step (d) back to the oligomerization step, thereby increasing the amount of C₁₆ unsaturated oligomers.

14. A process for preparing a renewable jet fuel comprising combining a renewable jet fuel blendstock prepared according to the method of claim 1 with a conventional jet fuel blendstock, whereby said renewable jet fuel meets or exceeds the requirements of ASTM D7566-10a.

15. The process of claim 14, further comprising combining said renewable jet fuel blendstock and said conventional jet fuel blendstock with one or more C₁₀-C₁₄ aromatic hydrocarbons.