SYSTEMS AND METHODS FOR POSITIONING FLEXIBLE FLOATING PHOTOBIOREACTORS

• US 20110281340A1
• Filed: 03/11/2011
• Published: 11/17/2011
• Est. Priority Date: 03/12/2010
• Status: Active Grant

• Current Assignee: Colorado State University Research Foundation
• Original Assignee: Solix Algredients, Inc.
• Inventors: HERBOLDSHEIMER, Daniel Robert, MCCARTY, Bryan Rhea, WILLSON, Bryan Dennis, TURNER, Christopher Wayne, LETVIN, Peter Allen
• Granted Patent: US 9,145,539 B2
• Time in Patent Office: Days
• US Class Current: 435/257.1
• CPC Class Codes: C12M 21/02 Photobioreactors culturing algae A01G33/00, A01H4/001, C12N1/12
• CPC Class Codes: C12M 23/22 Transparent or translucent parts glassware for laboratory use B01L3/00
• CPC Class Codes: C12M 23/26 flexible flexible containers for laboratory use B01L3/505
• CPC Class Codes: C12M 23/56 Floating elements
• CPC Class Codes: C12M 39/00 Means for cleaning the apparatus or avoiding unwanted deposits of microorganisms apparatus for cleaning laboratory receptacles or instruments B01L13/02; cleaning in general B08B
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

A top reference photobioreactor system according to an embodiment of the present invention includes a flexible floating photobioreactor having a buoyancy tube filled with a gas that is less dense, and a ballast tube filled with a substance, such as saltwater, that is more dense, than the liquid in which the photobioreactor floats. A top reference photobioreactor method according to an embodiment of the present invention includes controlling a depth of the top reference photobioreactor by controlling a volume and/or density of ballast in the ballast tube and/or by controlling a volume and/or density of gas in the buoyancy tube.

Claims

1. A photobioreactor system comprising:

a reservoir containing liquid, the liquid having a top surface level;

a photobioreactor, wherein the photobioreactor is flexible and is floating in the liquid, the photobioreactor comprising;

a growth chamber containing media in which organisms may be grown; and

a ballast chamber containing a fluid, the fluid having an effective density greater than that of the liquid, such that the ballast chamber exerts a force on the photobioreactor in a downward direction.

2. The photobioreactor system of claim 1, wherein the fluid is a first fluid, wherein the effective density is a first effective density, wherein the force is a first force, and wherein the photobioreactor further comprises:

a buoyancy chamber containing a second fluid, the second fluid having a second effective density less than that of the liquid, such that the buoyancy chamber exerts a second force on the photobioreactor in an upward direction.

3. The photobioreactor system of claim 2, wherein the photobioreactor further comprises:

a sparging chamber having a plurality of holes opening into the growth chamber, the sparging chamber containing a sparging gas or gas mixture that is configured to pass through the plurality of holes and rise through the media.

4. The photobioreactor system of claim 3, wherein the top surface level is a reservoir top surface level, wherein the growth chamber comprises a head space above a media top surface level, and wherein the head space accommodates accumulation of the sparging gas or gas mixture.

5. The photobioreactor system of claim 4, wherein the buoyancy chamber is isolated from, and directly adjacent to, the head space.

6. The photobioreactor system of claim 5, wherein the ballast chamber is isolated from, and directly adjacent to, a bottom of the growth chamber.

7. The photobioreactor system of claim 5, wherein the sparging chamber is located at a bottom of the growth chamber, and wherein the ballast chamber is isolated from, and directly adjacent to, the sparging chamber.

8. The photobioreactor system of claim 2, wherein the ballast chamber and the buoyancy chamber maintain the photobioreactor in a substantially upright position as the photobioreactor is floating in the liquid.

9. The photobioreactor system of claim 1, wherein the reservoir is a body of water selected from the group consisting of:

an ocean, a lake, a sea, a pond, a river, a basin, a tub, a pool, and a tank.

10. The photobioreactor system of claim 1, wherein the reservoir is a naturally occurring body of water.

11. The photobioreactor system of claim 2, wherein the first fluid is salt water, and wherein the second fluid is air.

12. The photobioreactor system of claim 1, wherein the ballast chamber comprises at least one port through which the fluid may be added to or removed from the ballast chamber

13. The photobioreactor system of claim 2, wherein the buoyancy chamber comprises at least one port through which the second fluid may be added to or removed from the buoyancy chamber.

14. The photobioreactor system of claim 1, wherein the photobioreactor is one of a plurality of photobioreactors each substantially the same as the photobioreactor, wherein the plurality of photobioreactors is floating in the liquid, and wherein the plurality of photobioreactors are positioned one next to the other such that a spacing between two adjacent photobioreactors of the plurality of photobioreactors is determined by widths of adjacent abutting ballast chambers.

15. The photobioreactor system of claim 14, wherein each of the plurality of photobioreactors comprises a top flap, wherein the top flap is configured to be placed over a top of an adjacent photobioreactor or over the top surface level of the liquid between adjacent photobioreactors.

16. The photobioreactor system of claim 1, wherein the photobioreactor is at least partially formed of a substantially transparent plastic film.

17. The photobioreactor system of claim 1, wherein the photobioreactor is at least partially formed of or coated by an anti-biofouling additive selected from the group consisting of:

polyethylene glycol (PEG), hyperbranched fluoropolymer (HBFP), polyethylene (PE), polyvinyl chloride (PVC), polymethylmethacrylate (PMMA), natural rubber (NR), polydimethylsiloxane (PDMS), polystyrene (PS), perfluoropolyether (PFPE), polytetrafluoroethylene (PTFE), and silicons and derivatives.

18. The photobioreactor system of claim 1, wherein the media comprises an anti-biofouling additive selected from the group consisting of:

polyethylene glycol (PEG), silicons and derivatives, biocides, fluorocarbons, and quatinary amines.

19. The photobioreactor system of claim 1, wherein at least a bottom surface of the ballast chamber is reinforced to minimize possible puncture.

20. A method for algae growth containment, comprising:

floating a photobioreactor in a reservoir containing liquid, the liquid having a top surface level, wherein the photobioreactor is flexible and comprises a growth chamber and a ballast chamber;

adding media to the growth chamber, wherein the media is adapted to support a suspension culture of algae; and

adding fluid to the ballast chamber, wherein the fluid has an effective density greater than that of the liquid, such that the ballast chamber exerts a force on the photobioreactor in a downward direction.

21. The method of claim 20, wherein the fluid is a first fluid, wherein the effective density is a first effective density, wherein the force is a first force, and wherein the photobioreactor further comprises a buoyancy chamber, the method further comprising:

adding a second fluid to the buoyancy chamber, wherein the second fluid has a second effective density less than that of the liquid, such that the buoyancy chamber exerts a second force on the photobioreactor in an upward direction.

22. The method of claim 20, wherein the reservoir is an ocean, the method further comprising:

growing the suspension culture of algae in the media; and

mixing the suspension culture of algae by floating the photobioreactor in a manner that permits the photobioreactor to move in response to waves in the ocean.

23. The method of claim 20, wherein the photobioreactor is one of a plurality of substantially similar photobioreactors, the method further comprising:

placing the plurality of substantially similar photobioreactors in a side-by-side configuration floating in the liquid; and

adjusting a spacing between adjacent photobioreactors by adding the fluid to, or subtracting the fluid from, the ballast chambers of adjacent photobioreactors.

24. The method of claim 20, further comprising:

adjusting a depth of the photobioreactor in the liquid by adding the fluid to, or subtracting the fluid from, the ballast chamber.

25. The method of claim 21, further comprising:

adjusting a depth of the photobioreactor in the liquid by adding the second fluid to, or subtracting the second fluid from, the buoyancy chamber.

26. The method of claim 25, further comprising:

subtracting the second fluid from the buoyancy chamber until the photobioreactor is substantially submerged below the top surface level.