Methods of and systems for producing diesel blend stocks

• US 8,741,145 B2
• Filed: 09/30/2011
• Issued: 06/03/2014
• Est. Priority Date: 04/06/2010
• Status: Expired due to Fees

• Current Assignee: Heliae Development, LLC (PT Perusahaan Perkebunan London Sumatra Indonesia Tbk)
• Original Assignee: Heliae Development, LLC (PT Perusahaan Perkebunan London Sumatra Indonesia Tbk)
• Inventors: Kale, Aniket
• Primary Examiner(s): DRODGE, JOSEPH W
• Application Number:
  US13/250,587
• Publication Number:
  US 20120021091A1
• Time in Patent Office: 977 Days
• Field of Search: 210/602, 210/610, 210/632, 210/33, 210/634, 210/639, 210/743, 210/749, 210/774, 210/633, 210/806, 210/770, 435/134, 435/262, 435/267, 435/271, 435/272, 443/07, 443/08, 446/05, 47/14, 554/12, 554/14, 554/20, 554/13, 554/21, 554/174, 554/175, 208/15, 208/49, 208/87, 208/133, 208/142, 203/28, 203/39, 203/91, 203/DIG.21, 203/DIG.25, 560/218, 562/600, 426/61, 426/65, 426/575, 426/655, 585/833, 585/836, 585/838, 530/370
• US Class Current: 210/634
• CPC Class Codes: A61P 7/00 Drugs for disorders of the blood or the extracellular fluid
• CPC Class Codes: B01D 11/04 of solutions which are liquid
• CPC Class Codes: C11B 1/10 by extracting
• CPC Class Codes: C11B 1/108 after-treatment, e.g. of miscellae
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

A method for producing biofuels is provided. A method of making biofuels includes dewatering substantially intact algal cells to make an algal biomass, extracting neutral lipids from the algal biomass, and esterifying the neutral lipids with a catalyst in the presence of an alcohol. The method also includes separating a water soluble fraction comprising glycerin from a water insoluble fraction comprising fuel esters and distilling the fuel esters under vacuum to obtain a C16 or shorter fuel esters fraction, a C16 or longer fuel ester fraction, and a residue comprising carotenoids and omega-3 fatty acids. The method further includes hydrogenating and deoxygenating at least one of (i) the C16 or shorter fuel esters to obtain a jet fuel blend stock and (ii) the C16 or longer fuel esters to obtain a diesel blend stock.

Claims

1. A method of making biofuels, comprising:

dewatering intact algal cells to make an algal biomass;

extracting a first liquid fraction from the algal biomass using a first solvent set, wherein the first solvent set comprises an alcohol, in a ratio of about 1 part algal biomass to about 1 part first solvent set, the first liquid fraction comprising a protein rich fraction;

extracting a second liquid fraction from the algal biomass using a second solvent set, wherein the second solvent set comprises an alcohol, in a ratio of about 1 part algal biomass to about 1 part second solvent set, the second fraction comprising polar lipids, the second solvent set having a lower polarity than the first solvent set, and the second liquid fraction having a higher percentage of polar lipids than the first liquid fraction;

extracting a third liquid fraction from the algal biomass using a third solvent set, wherein the third solvent set comprises an alcohol, in a ratio of about 1 part algal biomass to about 1 part third solvent set, the third fraction comprising neutral lipids, the third solvent set having a lower polarity than the first and second solvent sets, and the third liquid fraction having a higher percentage of neutral lipids than the first or second liquid fractions and a lower percentage of polar lipids than the second liquid fraction;

esterifying the neutral lipids with a catalyst in the presence of an alcohol;

separating a water soluble fraction comprising glycerin from a water insoluble fraction comprising fuel esters;

distilling the fuel esters under vacuum to obtain a C16 or shorter fuel esters fraction, a C16 or longer fuel ester fraction, and a residue comprising carotenoids and omega-3 fatty acids; and

hydrogenating and deoxygenating at least one of (i) the C16 or shorter fuel esters to obtain a jet fuel blend stock and (ii) the C16 or longer fuel esters to obtain a diesel blend stock.

2. The method of claim 1, further comprising heating the biomass during the step of extracting neutral lipids to a temperature below the boiling point of the solvent set at the conditions present during said step of extracting neutral lipids.

3. The method of claim 1, further comprising heating the biomass under a pressure greater than atmospheric pressure during the step of extracting neutral lipids.

4. The method of claim 1, further comprising recycling the residue comprising carotenoids and omega-3 fatty acids into an animal feed, a human food or a nutraceutical product.

5. The method of claim 1, further comprising growing the algal cells to produce neutral lipids by providing carbon dioxide to the algal cells as a carbon source.

6. The method of claim 1, further comprising growing the algal cells to produce the neutral lipids during bioremediation of wastewater by the algal cells.

7. The method of claim 6, wherein the bioremediation is integrated into a wastewater treatment plant.

8. The method of claim 1, wherein the algal biomass is wet.