NASA 1996 SBIR Phase I


PROPOSAL NUMBER : 96-1 16.07-7770

PROJECT TITLE : Atmospheric CO2 Controller for Plant Growth Chambers.

TECHNICAL ABSTRACT (LIMIT 200 WORDS)

Enhancing plant growth for food production in the space environment by control of growth parameters is a necessity for successful long duration manned spaceflight. Atmospheric carbon dioxide (CO2) is the primary carbon source for growing plants and one of the principal photosynthetic control parameters. A process capable of removing, storing, and supplying CO2 on demand is desirable for optimal Plant Growth Chamber (PGC) operation. During periods of high human and low plant activity, excess CO2 is removed from the PGC and stored. During periods of low human and high plant activity, CO2 is released to the PGC. Expendable compressed gases and sorbents mediate this process in commercial CO2 controllers. We propose the development of a CO2 removal, storage and release technology that is simple in design, robust, gravity independent, and capable of controlling CO2 concentrations for extended periods with minimal maintenance or expendable requirements. The proposed technology is based on the membrane equilibration of the PGC's atmosphere with a reversible CO2 sorbent. This solution's composition is designed to CO2 pressures (pCO2s). When pCO2 levels in the atmosphere exceed the solution's equilibrium pCO2, the excess is absorbed and stored until levels fall below the equilibrium pCO2 whereupon CO2 is liberated into the atmosphere. A constant pCO2 level is maintained dependent upon the alkanolamine solution's temperature.
POTENTIAL COMMERCIAL APPLICATIONS
The proposed technology is suitable for application in controlling CO2 levels in plant growth chambers and experimental greenhouses. pCO2 controllers based on this technology offer advantages of simplicity, low expendables and cost over currently available controllers based on compressed gases, mass flow controllers, CO2 sensors, and single use sorbents.
NAME AND ADDRESS OF PRINCIPAL INVESTIGATOR
Umpqua Research Company
P.O. Box 609
Myrtle Creek, OR 97457
NAME AND ADDRESS OF OFFEROR
Umpqua Research Company
P.O. Box 609
Myrtle Creek, OR 97457