Controlled system for supporting algae growth with adsorbed carbon dioxide
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).
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 CO 2 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 CO 2 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.