PhotobioreactorFrom Phyco.orgA photobioreactor is a device that houses and cultivates algae. It provides a suitable environment for algae growth, supplying light, nutrients, air, and heat to the culture.
[edit] ArrangementsThere are several physical arrangements of a photobioreactor. These include the following:
[edit] LightingPlant cells use only a small fraction of the sunlight that hits them. Some sources that can be used to provide the light energy required to sustain photosynthesis include fluorescent lighting, high-intensity discharge lighting, light-emitting diodes, natural sunlight, and directed sunlight. For more information, see: Light Requirements [edit] NutrientsNutrients are a major determining factor in how fast algae grows and what composition it develops. [edit] Gases[edit] HeatingAlgae live in water from the equator to the Arctic and Antarctic. Consequently, there is no single temperature is best for all algae. One theory is that an algae species will tolerate a few degrees above the maximum summer temperature of its natural environment. Thus, the temperature range that a given algae species will tolerate may estimated by knowing its environmental range. However, to know the temperature at which an algae species grows best must be determined by experiment. [edit] CultivationFrom the NREL's review of the Aquatic Species Laboratory's work[1]: The Roswell test site successfully completed a full year of operation with reasonable control of the algal species grown. Single day productivities reported over the course of one year were as high as 50 grams of algae per square meter per day, a long-term target for the program. Attempts to achieve consistently high productivities were hampered by low temperature conditions encountered at the site. The desert conditions of New Mexico provided ample sunlight, but temperatures regularly reached low levels (especially at night). If such locations are to be used in the future, some form of temperature control with enclosure of the ponds may well be required. ... The algae species studied in this program can produce up to 60% of their body weight in the form of TAGs. See: Cultivation [edit] HarvestingPhotobioreactors can be set up to be continually harvested-- the majority of the larger cultivation systems-- or by harvesting a batch at a time, such as in polyethlyene bag cultivation. A batch photobioreactor is set up with nutrients and algal seed, and allowed to grow until the batch is harvested. A continuous photobioreactor is harvested either continually, as daily, or more frequently, and have growing medium fed at a constant rate, while algae is harvested at the same rate. See: Harvesting [edit] External links
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