Controlled system for supporting algae growth with adsorbed carbon dioxide

• US 10,123,495 B2
• Filed: 01/14/2015
• Issued: 11/13/2018
• Est. Priority Date: 06/16/2010
• Status: Expired due to Fees

• Current Assignee: General Atomics, Inc.
• Original Assignee: General Atomics, Inc.
• Inventors: Ordway, David W., Hazlebeck, David A.
• Primary Examiner(s): Beisner, William H.
• Application Number:
  US14/596,451
• Publication Number:
  US 20150173317A1
• Time in Patent Office: 1,399 Days
• CPC Class Codes: A01G 33/00 Cultivation of seaweed or algae
• CPC Class Codes: B01D 53/14 by absorption
• CPC Class Codes: C12M 21/02 Photobioreactors culturing algae A01G33/00, A01H4/001, C12N1/12
• CPC Class Codes: C12M 41/32 of substances in solution
• CPC Class Codes: C12M 41/34 of gas
• CPC Class Codes: C12M 41/48 Automatic or computerized control automatic analysis G01N35/00
• CPC Class Codes: Y02A 40/80 in fisheries management
• CPC Class Codes: Y02E 50/30 Fuel from waste, e.g. synthetic alcohol or diesel

Abstract

A system and method for creating a useful carbon-enriched media in a reactor which will assimilate carbon into an algae biomass, requires measuring a respective carbon concentration of the media, C_(measured), as it enters, and as it leaves the reactor. Operationally, desired carbon concentration values are preset, C_(set), and are provided along with values obtained for C_(measured) as input to a system controller. Respective differentials between C_(measured) and C_(set) at the reactor'"'"'s input and output ports are determined by the controller and are used to control a volumetric fluid flow rate of the media through the reactor. Specifically, the controller establishes a volumetric fluid flow rate of the media as it is passed through an absorber where the media is carbon-enriched by interaction with combustion gases from an external source (e.g. a power plant).

Claims

1. A system for capturing carbon in a carbon-poor media to create a carbon-enriched media thereof, for assimilation of the carbon captured by the enriched media into an algae biomass, the system comprising:

a reactor for growing algae biomass in the media, wherein the reactor has an input port and an output port;

an absorber having a plurality of panels, wherein each panel has a surface area, and wherein the absorber has a first input port, a second input port, a first output port and a second output port;

a source of combustion gases with a conduit for directing the combustion gases into the absorber through the first input port of the absorber;

a pump for establishing a volumetric flow rate of carbon-poor media from the output port of the reactor and into the second input port of the absorber, wherein the carbon-poor growth media is presented on panel surface areas in the absorber for a counter current flow interaction with the combustion gases to create the carbon-enriched growth media for discharge from the first output port of the absorber and into the reactor through the input port of the reactor;

a first sensor for measuring a first carbon concentration level, C_1(measured), in the reactor at the output port of the reactor;

a second sensor for measuring a second carbon concentration level, C_2(measured), of media discharged from the first output port of the absorber; and

a controller for operating the pump with input from the first and second sensors to establish an optimized assimilation of captured carbon from the carbon-enriched growth media into the algae biomass in the reactor.

2. A system as recited in claim 1 wherein a first preset carbon concentration C_1(set) is based on an apparent carbon dioxide CO₂ concentration gradient determined by an interaction between aqueous media in the reactor and the atmosphere of the local environment of the reactor, wherein a second preset carbon concentration C_2(set) is based on an apparent carbon dioxide CO₂ concentration gradient determined by an interaction between combustion gases and relatively carbon-poor growth media in the absorber, and further wherein C_1(set) and C_2(set) are predetermined inputs to the controller.

3. A system as recited in claim 2 wherein the pump is activated to operate with a predetermined high fluid flow rate when C_1(measured) is below C_1(set) and, alternatively, when C_2(measured) is below C_2(set), and further wherein the pump is activated to operate with a predetermined low fluid flow rate when C_1(measured) is above C_1(set).

4. A system as recited in claim 2 wherein a gaseous component of the local environment of the reactor is selected from the group consisting of bicarbonate, carbonic acid and carbon dioxide.

5. A system as recited in claim 1 wherein the reactor is selected from the group consisting of a pond, a plug flow reactor, and an expanding plug flow reactor.

6. A system as recited in claim 1 wherein the first sensor is located between the output port of the reactor and the second input port of the absorber.

7. A system as recited in claim 1 further comprising a recycling pump for transferring media from the second output port of the absorber and back into the absorber via the second input port of the absorber.

8. A system as recited in claim 7 wherein the recycling pump is activated to transfer media back into the absorber when C_2(measured) falls below a predetermined value.