Photobioreactor

• US 20030073231A1
• Filed: 07/12/2002
• Published: 04/17/2003
• Est. Priority Date: 10/17/2001
• Status: Active Grant

• Current Assignee: CO2 Solutions Inc.
• Original Assignee: CO2 Solutions Inc.
• Inventors: Dutil, Frederic
• Granted Patent: US 6,602,703 B2
• Time in Patent Office: Days
• US Class Current: 435/292.1
• CPC Class Codes: C12M 21/02 Photobioreactors culturing algae A01G33/00, A01H4/001, C12N1/12
• CPC Class Codes: C12M 31/10 by light emitting elements located inside the reactor, e.g. LED or OLED
• 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: Y10S 165/004 Sight glass

Abstract

A photobioreactor is disclosed for cultivating a photosynthetic organism. This photobioreactor provides innovative features that allow an easy cleaning of the light source. The photobioreactor has a container for containing a liquid culture medium for cultivating photosynthetic organisms, light-emitting tubes mounted within the container. The photobioreactor also has cleaning devices mounted within the container for cleaning the outer surface of the light-emitting tubes and actuators for actuating the cleaning devices.

Claims

1. A photobioreactor comprising

a container for containing a liquid culture medium for cultivating photosynthetic organisms,

a plurality of parallel light-emitting tubes mounted within the container and extending in a first direction, each light-emitting tube having an outer surface;

cleaning means mounted within the container for cleaning the outer surface of the light-emitting tubes; and

actuating means for actuating the cleaning means.

2. A photobioreactor as claimed in claim 1, wherein the cleaning means comprises a support frame movable in said first direction, the support frame comprising a plurality of cleaning devices adapted to clean said outer surface of the light-emitting tubes, each of said cleaning devices being associated with a respective one of said light-emitting tubes.

3. A photobioreactor as claimed in claim 2, wherein the support frame comprises at least one plate mounted at right angle to the first direction, said at least one plate comprising a plurality of openings each sized and shaped to receive a respective one of said light-emitting tubes, and each of said cleaning devices being located in a respective one of said openings.

4. A photobioreactor as claimed in claim 3, wherein each of said cleaning devices comprises a brushing means for brushing the outer surface of a respective lightemitting tube.

5. A photobioreactor as claimed in claim 4, wherein the brushing means comprises a plurality of bristles.

6. A photobioreactor as claimed in claim 3, comprising hanging means for hanging the support frame within the container.

7. A photobioreactor as claimed in claim 6, wherein

the container has a rectangular configuration with a first and a second pair of opposite sidewalls, the light-emitting tubes extending between said first pair of sidewalls;

the support frame comprises a bottom side, and a top side with two end portions, and

the hanging means comprises;

a pair of support members provided respectively on each one of said sidewalls of the second pair of sidewalls; and

a pair of resting members, a first one provided on one of said end portion of the top side of the support frame and a second one provided on the other end portion of the top side of the support frame, each of said resting members being respectively adapted to rest on one of said support members and being further movable along the support members.

8. A photobioreactor as claimed in claim 7, wherein said pair of support members comprises a rail mounted on each one of said sidewalls.

9. A photobioreactor as claimed in claim 8, wherein said pair of resting members comprises a roller for rolling on the rail.

10. A photobioreactor as claimed in claim 3, wherein said at least one plate of the support frame is provided with a plurality of through-holes allowing free passage of the culture medium through the plate.

11. A photobioreactor as claimed in claim 1, further comprising a gas dispenser for dispensing CO₂ enriched air into the culture medium.

12. A photobioreactor as claimed in claim 11, wherein the gas dispenser comprises at least one dispensing tube spanning generally parallel to the light-emitting tubes underneath the support frame, the dispensing tube comprising a gas inlet for receiving the CO₂ enriched air and a plurality of gas outlet for dispensing the CO₂ enriched air into the container.

13. A photobioreactor as claimed in claim 12, wherein the support frame comprises a bottom edge comprising brushing means for brushing an outer surface of said at least one dispensing tube.

14. A photobioreactor as claimed in claim 13, wherein the brushing means comprises a plurality of bristles.

15. A photobioreactor as claimed in claim 2, wherein the actuating means comprises a driving endless screw operatively connected to the support frame and a power means for inducing a rotation movement to said endless screw, said rotation movement causing the support frame to move in said first direction.

16. A photobioreactor as claimed in claim 15, wherein said power means is a reversible electric motor or a manual driving handle for imparting the rotation movement to said endless screw.

24. A culture unit as claimed in claim 23, wherein the photobioreactor is as defined in claim 1.

25. A process for producing photosynthetic organisms, the process comprising the steps of:

a) cultivating a photosynthetic organism in a photobioreactor as defined in claim 1, and thereby obtaining a liquid culture medium containing photosynthetic organisms;

b) removing from said photobioreactor a portion of said liquid culture medium; and

c) separating the liquid culture medium of step b) into a solid phase containing the photosynthetic organisms and a liquid phase.

26. A process as claimed in claim 25, further comprising the steps of):

producing a solution of bicarbonate ions and hydrogen ions in a bioreactor comprising a reaction chamber containing immobilized carbonic anhydrase or analog thereof capable of catalyzing the hydration of dissolved CO₂ into bicarbonates ions and hydrogen ions; and

feeding the photobioreactor with the solution of bicarbonates ions and hydrogen ions produced in the bioreactor.

27. A process as claimed in claim 26, comprising the step of:

feeding the bioreactor with the liquid phase obtained in step c).

28. A process as claimed in claim 27, wherein step c) of separating comprises a process selected from the group consisting of filtration, flocculation, sedimentation and centrifugation.

29. A process as claimed in claim 28, comprising, prior to the step of feeding the photobioreactor the step of:

adding to said solution of bicarbonates ions and hydrogen ions a concentrate liquid culture medium, and thereby forming a liquid solution.

30. A process as claimed in claim 29, comprising the step of feeding said liquid solution into a heat exchanger for recovering heat from the liquid solution and cooling the same.

17. A culture unit for cultivating photosynthetic organisms, comprising:

a photobioreactor for cultivating a photosynthetic organism in a liquid culture medium;

a bioreactor for producing bicarbonate ions and hydrogen ions from a CO₂-containing gas, the bioreactor comprising;

a reaction chamber containing immobilized carbonic anhydrase or analog thereof capable of catalyzing the hydration of dissolved CO₂ into said bicarbonates ions and hydrogen ions,

a liquid inlet in fluid communication with the reaction chamber, for receiving a liquid,

a gas inlet in fluid communication with the reaction chamber, for receiving a CO₂-containing gas; and

a liquid outlet in fluid communication with the reaction chamber, for dispensing a solution containing said bicarbonates ions and hydrogen ions and

means for transferring said solution of bicarbonates ions and hydrogen ions dispensed from said liquid outlet to the photobioreactor.

18. A culture unit as claimed in claim 17, comprising

means for removing a portion of the liquid culture medium from the photobioreactor and

means for separating said portion of the liquid culture medium into a solid phase containing the organisms and into a liquid phase.

19. A culture unit as claimed in claim 18, comprising:

means for transferring the liquid phase obtained in the separating means into the liquid inlet of the bioreactor.

20. A culture unit as claimed in claim 19, comprising:

means for adding to said solution of bicarbonate ions and hydrogen ions a concentrate of liquid culture medium.

21. A culture unit as claimed in claim 20, comprising:

a mixing unit for mixing said concentrate of liquid culture medium with the solution of bicarbonate ions and hydrogen ions so as to obtain a liquid solution.

22. A culture unit as claimed in claim 21, comprising

means for recovering heat from the liquid solution and cooling the same.

23. A culture unit as claimed in claim 22, comprising:

means for transferring said liquid solution to the photobioreactor.