METHOD AND SYSTEM OF PROVIDING CARBON DIOXIDE-ENRICHED GAS FOR GREENHOUSES

• US 20090007779A1
• Filed: 12/28/2007
• Published: 01/08/2009
• Est. Priority Date: 05/17/2007
• Status: Abandoned Application

• Current Assignee: Philippe A. Coignet, Rajeev S. Prabhakar
• Original Assignee: Philippe A. Coignet, Rajeev S. Prabhakar
• Inventors: PRABHAKAR, Rajeev S., COIGNET, Philippe A.
• Application Number:
  US11/966,786
• Publication Number:
  US 20090007779A1
• Time in Patent Office: Days
• US Class Current: 95/51
• CPC Class Codes: A01G 9/18 Greenhouses for treating plants with carbon dioxide or the like

Abstract

A feed gas is separated into a CO₂-lean stream and a CO₂-enriched stream at a CO₂ enriching unit. The CO₂-enriched gas is fed to a greenhouse to enhance plant growth. The feed gas may include air and/or vent gas from the greenhouse.

Claims

1. A method of providing a CO₂-enriched gas to a greenhouse, comprising the steps of:

feeding a feed gas to a CO₂ enriching unit;

separating the feed gas into a CO₂-lean stream and a CO₂-enriched stream; and

feeding the CO₂-enriched stream to a greenhouse containing plants.

2. The method of claim 1, wherein the feed gas is air.

3. The method of claim 1, wherein the feed gas comprises a vent gas collected from an outlet of the greenhouse.

4. The method of claim 1, further comprising the step of injecting CO₂ into the greenhouse from a backup CO₂ source.

5. The method of claim 4, further comprising the step of vaporizing a portion of liquid CO₂ from a vessel containing liquid CO₂.

6. The method of claim 4, wherein the backup CO₂ source is a flue gas-generating fuel burner.

7. The method of claim 1, wherein the CO₂ enriching unit is an adsorbent-based unit selected from the group consisting of a pressure swing adsorption unit, a vacuum swing adsorption unit, a thermal swing adsorption unit, an electrical swing adsorption unit, and combinations thereof.

8. The method of claim 7, wherein an adsorbent in the adsorbent-based unit is selected from the group consisting of a molecular sieve, activated alumina, activated carbon, silica gel, metal oxides, a mixture of NaOH and CaO, carbonic anhydrase enzyme, an enzyme derived from carbonic anhydrase, and solid amines.

9. The method of claim 1, wherein the CO₂ enriching unit is a membrane.

10. The method of claim 1, wherein an interior of the greenhouse has a target CO₂ concentration in a range of from about 550 ppm to about 2000 ppm.

11. The method of claim 1, wherein an interior of the greenhouse has a target CO₂ concentration in a range of from a concentration of CO₂ found in air surrounding the greenhouse to about 2000 ppm.

12. The method of claim 1, further comprising the step of selecting a target CO₂ concentration to be achieved in the greenhouse, wherein a CO₂ concentration of the gas feed stream is less than the target CO₂ concentration.

13. The method of claim 1, wherein the feed gas is air and the CO₂ enriching unit is an adsorbent-based unit using activated carbon as an adsorbent.

14. The method of claim 1, wherein the feed gas is air and the CO₂ enriching unit is a membrane.

15. A system for growing plants in a CO₂-enriched atmosphere, comprising:

a greenhouse containing plants; and

a CO₂ enriching unit in fluid communication with the greenhouse adapted and configured to separate a feed gas stream into a CO₂-enriched stream and a CO₂-lean stream.

16. The system of claim 15, wherein a vent of the greenhouse is in fluid communication with an inlet of the CO₂ enriching unit.

17. The system of claim 16, further comprising a backup source of CO₂ in fluid communication with the greenhouse.

18. The method of claim 17, wherein the backup CO₂ source is liquid CO₂, said source of CO₂ being adapted and configured to allow a portion of the liquid CO₂ to be vaporized and injected into the greenhouse.

19. The method of claim 17, wherein the backup CO₂ source is a flue gas-generating fuel burner.

20. The system of claim 15, wherein the CO₂ enriching unit is an adsorbent-based unit selected from the group consisting of a pressure swing adsorption unit, a vacuum swing adsorption unit, a thermal swing adsorption unit, an electrical swing adsorption unit, and combinations thereof.

21. The system of claim 20, wherein an adsorbent in the adsorbent-based unit is selected from the group consisting of a molecular sieve, activated alumina, activated carbon, silica gel, metal oxides, a mixture of NaOH and CaO, carbonic anhydrase enzyme, an enzyme derived from carbonic anhydrase, and solid amines

22. The system of claim 15, wherein the CO₂ enriching unit is a membrane.

23. The system of claim 15, wherein the feed gas is air and the CO₂ enriching unit is an adsorbent-based unit using activated carbon as an adsorbent.

24. The system of claim 15, wherein the feed gas is air and the CO₂ enriching unit is a membrane.