Open Pond System

Aquatic Energy Open-pond system that is yielding 2500 gallons per acre without using an external CO2 source. 

There is the possibility that in a photobioreactor system, the oil and algae water may become an emulsion-type mixture and cause further separation problems. In an open pond system, a thick layer of oil may prevent the light penetrating to the algae and inhibit the algal growth. 

Production Systems validation of the open pond system for mass production (scales ranging from <100m to lOOOm ) ... 

Because the defining feature of open pond systems is that they are open to the environment, there is a potential for contamination of the medium from other species of algae or protozoa which could outcompete the species of interest and therefore reduce the productivity of the culture. Because of this limitation, open systems must utilize species that are tolerant to extreme environments. Dumliella salina is one of the most tolerant eukaryotic organisms known based on its ability to tolerate salinity ranging from 3% to 31% NaCl and temperatures ranging from lower than 0°C to above 38°C. It is due in part to these characteristics which have allowed for the creation of a large global market for -carotene from D. salina as detailed in Section 6 of this chapter. 

Weissman JC, Goebel RP. Design and analysis of microalgal open pond systems for the purpose of producing fuels. Colorado Golden 1987. 

Usually, smaller outdoor raceway ponds produce higher algal yield than a larger pond. Currently, 98% of commercial algae are produced in open systems. The open-pond system can be easily scaled up to several acres for individual ponds and can be... 

The increased productivities achievable in photobioreactors versus open ponds were demonstrated by Tredici and Materassi (1992). However, comparison of open pond systans and various photobioreactors for a number of species, including Chlorella pyrenoidosa, Tetraselmis chui and Spirulina spp., made by Lee (2001) showed that productivities from photobioreactors need not surpass those of open pond systems. More recent estimates of productivities (Chisti, 2007 Wiffjels and Barbosa, 2010) suggest that photobioreactors will be essential to achieve the high production necessary for commercial production of bioenergy and other bioproducts. 

In Australia, Campbell et al. (2011) performed LCAfor an open-pond system. In this study, three different CO2 supplementations and two production scenarios were tested as compared to canola and ultra-low sulfur diesel. Comparisons were based on GHG emissions. They demonstrated that algae have reduced GHG emissions when the algal production facilities... 

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