Methods for dewatering wet algal cell cultures

• US 8,187,463 B2
• Filed: 10/07/2011
• Issued: 05/29/2012
• 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:
  US13/269,392
• Publication Number:
  US 20120024797A1
• Time in Patent Office: 235 Days
• Field of Search: 210/602, 210/610, 210/632, 210/633, 210/634, 210/639, 210/770, 210/774, 210/805, 210/806, 210/651, 210/702, 210/703, 210/787, 435/134, 435/262, 435/267, 435/271, 435/272, 443/07, 443/08, 446/05, 47/14, 554/12, 554/14, 554/20
• 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 of dewatering algae and recycling water therefrom is presented. A method of dewatering a wet algal cell culture includes removing liquid from an algal cell culture to obtain a wet algal biomass having a lower liquid content than the algal cell culture. At least a portion of the liquid removed from the algal cell culture is recycled for use in a different algal cell culture. The method includes adding a water miscible solvent set to the wet algal biomass and waiting an amount of time to permit algal cells of the algal biomass to gather and isolating at least a portion of the gathered algal cells from at least a portion of the solvent set and liquid of the wet algal biomass so that a dewatered algal biomass is generated. The dewatered algal biomass can be used to generated algal products such as biofuels and nutraceuticals.

Claims

1. A method of dewatering a wet algal cell culture, comprising:

a. removing at least a portion of liquid in an algal cell culture using a sintered metal tube filter to obtain a wet algal biomass fraction having a lower liquid content than the algal cell culture, the algal cells of the wet algal biomass fraction having a chlorophyll concentration;

b. recycling at least a portion of the liquid removed from the algal cell culture to a different algal cell culture wherein the different algal cell culture is combined with the at least a portion of the liquid removed from the algal cell culture;

c. adding a water miscible solvent set to the wet algal biomass fraction and waiting an amount of time to permit algal cells of the algal biomass fraction to gather; and

d. isolating at least a portion of the gathered algal cells from at least a portion of the solvent set and liquid of the wet algal biomass fraction so that a dewatered algal biomass is generated, wherein the isolation of the algal cells from the solvent set is carried out so as to minimize one or more of the degradation, denaturation, oxidation, decomposition, or destruction of chlorophyll, carotenoids, and lipids, wherein the liquid removed is less than all of the liquid of the wet algal biomass fraction.

2. The method of claim 1, wherein the dewatered algal biomass is an algal paste or an algal cake.

3. The method of claim 1, wherein the water miscible solvent set is at least about 10% less or more dense than water.

4. The method of claim 1, wherein the solvent set comprises one or more of glycols, glycerine, acetone, acetonitrile, and alcohols.

5. The method of claim 1, wherein the algal cells are not lysed by the adding of the water miscible solvent set.

16. The method of claim 1, wherein the water miscible solvent is added to achieve a weight/weight solvent to biomass ratio of between about 1:

1 to about 1;

10.

6. A method of dewatering a wet algal cell culture, comprising:

a. removing at least a portion of liquid in an algal cell culture using at least one of a membrane, centrifugation, a sintered metal tube, dissolved gas flotation, and flocculation to obtain a wet algal biomass fraction having a lower liquid content than the algal cell culture, the algal cells of the wet algal biomass fraction having a chlorophyll concentration;

b. recycling at least a portion of the liquid removed from the algal cell culture to a different algal cell culture, wherein the different algal cell culture is combined with the at least a portion of the liquid removed from the algal cell culture;

c. adding a water miscible solvent set to the wet algal biomass fraction and waiting an amount of time to permit algal cells of the algal biomass fraction to gather; and

d. isolating at least a portion of the gathered algal cells from at least a portion of the solvent set and liquid of the wet algal biomass fraction so that a dewatered algal biomass is generated, wherein the isolation of the algal cells from the solvent set is carried out so as to minimize one or more of the degradation, denaturation, oxidation, decomposition, or destruction of chlorophyll, carotenoids, and lipids, wherein the liquid removed is less than all of the liquid of the wet algal biomass fraction.

7. The method of claim 6, wherein the dewatered algal biomass is an algal paste or an algal cake.

8. The method of claim 6, wherein the water miscible solvent set is at least about 10% less or more dense than water.

9. The method of claim 6, wherein the solvent set comprises one or more of glycols, glycerine acetone, acetonitrile, and alcohols.

10. The method of claim 6, wherein the algal cells are not lysed by the adding of the water miscible solvent set.

17. The method of claim 6, wherein the water miscible solvent is added to achieve a weight/weight solvent to biomass ratio of between about 1:

1 to about 1;

10.

11. A method of dewatering a wet algal cell culture, comprising:

a. removing at least a portion of liquid in a wet algal cell culture to obtain a wet algal biomass fraction having a lower liquid content than the algal cell culture, the algal cells of the wet algal biomass fraction having a chlorophyll concentration, wherein the liquid removed is less than all of the liquid of the wet algal biomass fraction;

b. adding a first water miscible solvent set, comprising one or more solvents, to the wet algal biomass fraction;

c. generating a substantially liquid phase and a substantially solid phase from the mixture of the wet algal biomass fraction and water miscible solvent set;

d. isolating at least a portion of the substantially solid phase, the substantially solid phase comprising algal cells, wherein the isolation of the algal cells from the solvent set is carried out so as to minimize one or more of the degradation, denaturation, oxidation, decomposition, or destruction of chlorophyll, carotenoids, and lipids;

e. adding a second water miscible solvent set, comprising one or more solvents, to the isolated portion of the substantially solid phase;

f. isolating at least a portion of algae solids of the mixture of the substantially solid phase and second water miscible solvent set by sedimentation or flotation of the algae solids;

g. recycling at least a portion of at least one of the first and second water miscible solvent set to a subsequent algal cell culture dewatering process, wherein the subsequent algal culture cell culture dewatering process is conducted on a different algal cell culture; and

h. recycling at least a portion of the liquid removed from the algal cell culture to a different algal cell culture is combined with the at least a portion of the liquid removed from the algal cell culture.

12. The method of claim 11, wherein the dewatered algal biomass is an algal paste or an algal cake.

13. The method of claim 11, wherein the water miscible solvent set is at least about 10% less or more dense than water.

14. The method of claim 11, wherein at least one of the first water miscible solvent set and the second water miscible solvent set comprises at least one of an alcohol, and glycerine.

15. The method of claim 11, wherein the algal cells are not lysed by the adding the first water miscible solvent set or the second water miscible solvent set.

18. The method of claim 11, wherein the water miscible solvent is added to achieve a weight/weight solvent to biomass ratio of between about 1:

1 to about 1;

10.