Design of Scaleable Photobioreactors for Mass Production of Algae for Biofuel Production
A presentation from the University of Arizona on photobioreactors on open raceways and vertical bubble columns.
Comparative evaluation of compact photobioreactors for large-scale monoculture of microalgae
Paper compares horizontal tubular photobioreactors and vertical bubble column and airlift vessel type photobioreactors and concludes that vertical reactors appear to be the only ones that can be effectively used in large-scale culture of microalgae.
Bubble columns are more scaleable and provide a relatively homogeneous culture environment. In addition, the low surface– to–volume bubble columns demand less cooling. Vertical columns experience less photoinhibition during periods of high light intensity; during low light seasons such as winter, the vertical
reactors still receive substantial total radiation because they receive more reflected light than do
horizontal tubes.
Photobioreactors for mass cultivation of algae (2007)
Another comaprison paper. See Table 1 or see below:
Open ponds
Adv: Relatively economical, easy to clean up after cultivation, good for mass cultivation of algae
Disadv: Little control of culture conditions, difficulty in growing algal cultures for long periods, poor productivity, occupy large land mass, limited to few strains of algae, cultures are easily contaminated
Vertical-column photobioreactors
Aerated vertical columns
Comparative evaluation of compact photobioreactors for large-scale monoculture of microalgae
Paper compares horizontal tubular photobioreactors and vertical bubble column and airlift vessel type photobioreactors and concludes that vertical reactors appear to be the only ones that can be effectively used in large-scale culture of microalgae.
Bubble columns are more scaleable and provide a relatively homogeneous culture environment. In addition, the low surface– to–volume bubble columns demand less cooling. Vertical columns experience less photoinhibition during periods of high light intensity; during low light seasons such as winter, the vertical
reactors still receive substantial total radiation because they receive more reflected light than do
horizontal tubes.
Photobioreactors for mass cultivation of algae (2007)
Another comaprison paper. See Table 1 or see below:
Open ponds
Disadv: Little control of culture conditions, difficulty in growing algal cultures for long periods, poor productivity, occupy large land mass, limited to few strains of algae, cultures are easily contaminated
The best annual averaged bioproductivity of outdoor open algal ponds is ∼1 g dry weight m−2 h−1, while corn, sugar cane, and closed algal photobioreactors have achieved ∼2–3 g dry weight m−2 h−1
Vertical-column photobioreactors
Aerated vertical columns
Air-lift bioreactors are similar to bubble column reactors, but differ by the fact that they contain a draft tube which improves circulation and oxygen transfer and equalizes shear forces in the reactor. The more homogeneous distribution of exposure time or higher hydrodynamic stress in the airlift reactor resulted in a higher growth rate. (See link)
Vertical bubble columns
Adv: High mass transfer, good mixing with low shear stress, low energy consumption, high potentials for scalability, easy to sterilize, readily tempered, good for immobilization of algae, reduced photoinhibition and photo-oxidation
Disadv: Small illumination surface area, their construction require sophisticated materials, shear stress to algal
cultures, decrease of illumination surface area upon scale-up
Flat-plate photobioreactors
u-shaped disposable plastic bag located between two iron frames. Frame and plastic bag are 1.5m high and 2.5m long, with a volume of 250 L.
Adv: Large illumination surface area, suitable for outdoor cultures, good for immobilization of algae, good light path, good biomass productivities, relatively cheap, easy to clean up, readily tempered, low oxygen buildup
Disadv: Scale-up require many compartments and support materials, difficulty in controlling culture temperature, some degree of wall growth, possibility of hydrodynamic stress to some algal strains
Tubular photobioreactors
Tubular photobioreactors
Adv: Large illumination surface area, suitable for outdoor cultures, fairly good biomass productivities, relatively cheap
Disadv: Gradients of pH, dissolved oxygen and CO2 along the tubes, fouling, some degree of wall growth, requires large land space
References
Disadv: Gradients of pH, dissolved oxygen and CO2 along the tubes, fouling, some degree of wall growth, requires large land space
References
Phycotech is currently offering photobioreactor systems ranging from 200l to 10,000l. The systems include nutrient addition, pH control. Other parameters maybe control depending on the customers requirement. Controls range from simple pH control to advanced PLC control with Touch Screen interface. photobioreactors
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