Applications of the rotating photobioreactor

• US 8,895,279 B2
• Filed: 09/03/2013
• Issued: 11/25/2014
• Est. Priority Date: 12/02/2010
• Status: Expired due to Fees

• Current Assignee: Brian J. Coyne
• Original Assignee: Dennis A. Burke
• Inventors: Burke, Dennis A.
• Primary Examiner(s): UNDERDAHL, THANE E
• Application Number:
  US13/987,795
• Publication Number:
  US 20140045234A1
• Time in Patent Office: 448 Days
• Field of Search: None
• US Class Current: 435/168
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 53/268 by diffusion
• CPC Class Codes: B01D 53/84 Biological processes
• CPC Class Codes: C07C 29/74 Separation; Purification; Use of additives, e.g. for stabilisation
• CPC Class Codes: C12M 21/02 Photobioreactors culturing algae A01G33/00, A01H4/001, C12N1/12
• CPC Class Codes: C12M 21/04 for producing gas, e.g. biogas digesters for manure with production of biogas A01C3/028, biological treatment of water, waste water or sewage C02F3/00, C02F11/02, preparation of natural gas or syngas C10L3/06, C10L3/10
• CPC Class Codes: C12M 23/58 Reaction vessels connected in series or in parallel combinations of bioreactors with other apparatus, C12M43/00
• CPC Class Codes: C12M 47/18 Gas cleaning, e.g. scrubbers; Separation of different gases separating dispersed particles from gases or vapours B01D45/00; separation of gases or vapours B01D53/00; gas washing apparatus for laboratory uses B01L5/04
• CPC Class Codes: C12N 1/12 Unicellular algae; Culture media therefor as new plants A01H13/00
• CPC Class Codes: C12N 13/00 Treatment of microorganisms or enzymes with electrical or wave energy, e.g. magnetism, sonic waves
• CPC Class Codes: C12P 1/00 Preparation of compounds or compositions, not provided for in groups C12P3/00 - C12P39/00, by using microorganisms or enzymes
• CPC Class Codes: C12P 2201/00 Pretreatment of cellulosic or lignocellulosic material for subsequent enzymatic treatment or hydrolysis
• CPC Class Codes: C12P 3/00 Preparation of elements or inorganic compounds except carbon dioxide recovery of carbon dioxides as by-products C12F3/02
• CPC Class Codes: C12P 5/00 Preparation of hydrocarbons or halogenated hydrocarbons
• CPC Class Codes: C12P 7/04 acyclic
• CPC Class Codes: C12P 7/16 Butanols
• CPC Class Codes: Y02A 50/20 Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel
• CPC Class Codes: Y02E 50/30 Fuel from waste, e.g. synthetic alcohol or diesel
• CPC Class Codes: Y02P 20/151 Reduction of greenhouse gas [GHG] emissions, e.g. CO2
• CPC Class Codes: Y02P 20/59 : Biological synthesis; Biological purification

Abstract

A method to recover and harvest nutrients from a liquid stream by incorporating them into microorganisms grown in a rotating photobioreactor. The method further includes optionally integrating the rotating photobioreactor with a composting or biogenic drying process.

Claims

1. A process for removing and harvesting nutrients from a nutrient-laden, liquid influent stream using autotrophic or phototrophic microorganisms growing in a rotating photobioreactor, said bioreactor including a vessel, a shaft mounted for rotation within said vessel about a shaft axis, a plurality of axially spaced-apart, growth plates attached to the shaft, each of the plates having surfaces to which a fixed film of the microorganisms is attached, means for rotating the shaft and plates about the axis, illumination means for shining light upon the microorganisms, and means for harvesting the microorganisms from the growth plates, comprising the simultaneous steps of:

(a) shining light upon the microorganisms with the illumination means;

(b) feeding the carbon source into the vessel; and

(c) feeding the influent stream past the growth plates such that the growth plates are partially submerged within the stream, whereby, as they grow, the microorganisms remove nutrients from the influent stream, capture the nutrients in biomass, emit oxygen gas, and convert the influent stream to a nutrient-deficient effluent stream; and

further comprising

(d) using the harvesting means to remove a portion of the microorganisms from the surfaces of the growth plates without diluting them in the effluent stream.

2. The process according to claim 1, wherein the vessel is uncovered.

3. The process according to claim 2, wherein the vessel is an open water body.

4. The process according to claim 1, wherein the vessel is covered.

5. The process of claim 4, wherein the vessel is a reactor tank.

6. The process of according to claim 1, wherein the vessel is a covered or uncovered waste conveyance channel.

7. The process according to claim 1, wherein the liquid within the vessel is maintained at a depth such that, while rotating, the growth plates spend between 35% and 65% of the time within said liquid and the remainder of the time out of said liquid.

8. The process of claim 1, wherein the surfaces of the growth plates include one or more of wood, cloth, porous ceramic, glass fiber or carbon fiber.

9. The process of claim 1, wherein the harvesting means includes

doctor blades disposed adjacent to the surfaces of the growth plates and engageable with said surfaces to shave portions of the microorganisms from those surfaces during rotation of the plates.

10. The process of claim 1, wherein the harvesting means includes one or more suction devices to suction microorganisms out of the vessel.

11. The process of claim 1, wherein the harvesting means is used continuously to remove portions of the microorganisms from the surfaces of the growth plates.

12. The process of claim 1, wherein the harvesting means is used intermittently to remove portions of the microorganisms from the surfaces of the growth plates.

13. The process of claim 1, wherein the carbon source includes one or more of air, carbon dioxide or bicarbonate.

14. The process of claim 1, wherein the liquid influent comprises anaerobic digestate.

15. The process of claim 14, further comprising passing a stripping gas past the growth plates to strip oxygen and/or to harvest any volatile products produced by the microorganisms as stripped gas.

16. The process of claim 15, wherein said anaerobic digestate contains dissolved bicarbonate and dissolved ammonium, whereby the microorganisms consume the bicarbonate, causing the pH of the liquid within the vessel to increase and converting ammonium to ammonia gas, which ammonia gas, together with water vapor, is stripped by passage of said stripping gas flowing past the growth plates as stripped gas.

17. The process of claim 16, further comprising adding supplemental bicarbonate or carbon dioxide to the influent stream.

18. The process of claim 16, wherein some of the effluent is recirculated through the rotating photobioreactor by adding it to the liquid influent stream in order to dilute the influent stream nutrient concentration, including the bicarbonate therein.

19. The process according to claim 16, further comprising inserting the stripped gas into a condenser cooled by a chiller and operating at a temperature less than the temperature of the liquid in the vessel, whereby the stripped gas and water vapor are condensed to form a condensate product and a gas that is deficient in said product.

20. The process of claim 19, further comprising recirculating the gas that is deficient in said product past the growth plates for further stripping.

21. The process of claim 19, wherein if the temperature of the gas that is deficient in said product is less than the temperature of the liquid in the vessel, further comprising heating said gas up to said temperature and recirculating said heated gas past the growth plates for further stripping.

22. The process of claim 19, further comprising discharging excess stripping gas and/or providing make up stripping gas through a pressure and vacuum relief valve.

23. The process according to claim 19, wherein the stripping gas includes one or more of air, methane, nitrogen, carbon dioxide and/or oxygen, comprising further concentrating the product by the steps of:

(a) conveying the stripped gas to an upstream side of a membrane disposed within a plenum, said membrane having a high permeability rate for water and a lower permeability rate for the stripping gas, and said stripping gas stream comprising stripping gas, water vapor, and a product volatile vapor;

(b) applying a differential pressure between the upstream side of the membrane and an opposite downstream side of the membrane, whereby water vapor passes through the membrane to the downstream side of the membrane as water vapor permeate within plenum gas, and the gas on the upstream side of the membrane becomes depleted of water vapor as plenum retentate gas; and

(c) combining the plenum gas formed in step (b) with the retentate gas that is deficient in condensate product to form a combined stripping gas.

24. The process of claim 23, further comprising passing the combined plenum stripping gas past the growth plates.

25. The process of claim 23, further comprising passing the combined plenum gas through a heater to raise the temperature thereof up to the temperature of the liquid in the vessel, and then passing the heated, combined plenum gas past the growth plates.

26. The process of any of claims 23, wherein the differential pressure across the membrane is maintained by a recirculating blower and control valve to cause the return flow of water vapor permeate with its latent heat to the rotating photo bioreactor.

27. The process of any of claim 23, wherein the effluent stream comprises a highly concentrated aqua ammonia concentrated to 2 to 12 percent (w/w) or more, suitable for use in the pretreatment of lignocellulosic biomass for renewable energy production.

28. The process of any of claims 23, wherein the effluent stream comprises a highly concentrated aqua ammonia concentrated to 20 percent (w/w) of more, suitable for use as diesel exhaust fluid (DEF).

29. The process of claim 1, wherein the illumination means provides natural and/or artificial light to the microorganisms and includes means to control the intensity of the light.

30. The process of claim 29, wherein the rotational speed of the growth plates and the intensity of the natural or artificial light are set such that the pH of the liquid in the vessel is maintained within the range of 6.5 to 11.0.

31. The process of claim 1, further comprising converting the microorganisms removed from the rotating bioreactor to organic fertilizer or to energy.

32. The process according to claim 15, further comprising

(a) inserting the oxygen stripped from the rotating photobioreactor into a composter;

(b) inserting wet solids into the composter;

(c) composting the wet solids in a composter, thereby producing carbon dioxide, heat and water vapor in the composter;

(d) discharging from the composter reduced and biogenically-dried organic compost; and

(e) conducting a carbon dioxide-enriched gas stream containing heat and water vapor away from the composter.

33. The process of claim 32, further comprising cooling the carbon dioxide-enriched gas stream in step (e) to form a condensate, and passing the cooled carbon dioxide past the growth plates in the vessel.

34. The process of claim 33, further comprising heating the stripped oxygen in step (a) of claim 32 before inserting the stripped oxygen into the composter.

35. The process of claim 15, wherein the microorganisms include designer photosynthetic organisms for photobiological production of butanol and related higher alcohols, whereby the stripped gas includes butanol or other linear or branched chain alcohols.

36. The process of claim 35, wherein the designer photosynthetic organisms are derived from marine algae and/or cyanobacteria that are viable in either seawater or groundwater.

37. The process according to claim 35, further comprising inserting the stripped gas into a condenser cooled by a chiller and operating at a temperature less than the temperature of the liquid in the vessel, whereby the stripped gas and water vapor are condensed to form a condensate product and a gas that is deficient in said product.

38. The process of claim 37, further comprising recirculating the gas that is deficient in said product past the growth plates for further stripping.

39. The process of claim 38, wherein if the temperature of the gas that is deficient in said product is less than the temperature of the liquid in the vessel, further comprising heating said gas up to said temperature and recirculating said heated gas past the growth plates for further stripping.

40. The process of claim 38, further comprising discharging excess stripping gas and/or providing make up stripping gas through a pressure and vacuum relief valve.

41. The process according to claim 38, wherein the stripping gas includes one or more of air, methane, nitrogen and/or oxygen, comprising further concentrating the product by the steps of:

(a) conveying the stripped gas to an upstream side of a membrane disposed within a plenum, said membrane having a high permeability rate for water and a lower permeability rate for the stripping gas, and said stripping gas stream comprising stripping gas, water vapor, and ammonia gas;

(b) applying a differential pressure between the upstream side of the membrane and an opposite downstream side of the membrane, whereby water vapor passes through the membrane to the downstream side of the membrane as water vapor permeate within plenum gas, and the gas on the upstream side of the membrane becomes depleted of water vapor as plenum retentate gas; and

(c) combining the plenum gas formed in step (b) with the retentate gas that is deficient in condensate product to form a combined stripping gas.

42. The process of claim 9, wherein the harvesting means includes one or more suction devices to suction microorganisms out of the vessel.