A Photo Bio Reactor (PBR)
is a system that provides an artificial environment for photosynthetic organisms
(Algae) to perform a chemical conversion. Scientists and engineers have been
developing several types of photo-bio reactors (PBR’s) over the past
fifty years to grow microorganisms that are used in a wide variety of applications.
Cultivated algae cultures can be used to produce human food,
animal feed, health food, therapeutics, chemicals, fuel, hormones, and fertilizer.
A prototype PBR was built at SDSU in 1998 that had a reactor capacity of 1
gallon. The prototype was inoculated with algae obtain from Argonne
National Laboratory and produced an algae biomass in excess of 25g.
The success of the prototype led to the decision to scale up the prototype
PBR to capacity of 500 gallons. The 500 gallon PBR is large enough to
study the feasibility of commercial production algae.
In the summer of 2000 research was initiated to evaluate the feasibility of
scaling up the prototype PBR. Major subsystems of the PBR were identified
as:
1. Light System
2. Air Handling System
3. Reactor Mixing System
4. Electrical System
5. Structural System
6. Instrumentation System
7. Nutrient System
Research revealed that little is known quantitatively about how the different
subsystems interact and affect algal biomass production in PBR. The
scaled up PBR design was then modified to allow for the testing of the effect
the different subsystems have on algal biomass production independently as
well as interactions of the subsystems. Test variables may be light
type (wavelength), intensity of light, mixing intensity, nutrient requirements,
control strategies, etc. To date five of the subsystems have been built.
Once the remaining subsystem have been built and all subsystems tested
the PBR will be used to evaluate subsystem impact on algal biomass production.