Open ponds, for microalgae

Biofixation of C02 by microalgae, especially as an option for the utilisation of flue gases from power plants, has been the subject of extensive investigations in the United States, Japan and Europe (IEA-GHG Biofixation Network). However, none of the related projects have demonstrated the feasibility of the concept at a pre-industrial level. What is more, C02 fixation efficiency is quite low because of the photobioreactors used in those pilot plants (raceway or open-ponds) (Figure 17). 

Seambiotic Agreement with NASA Glenn Research Center to develop an on-going collaborative R D program for optimization of open-pond microalgae growth processes. 

Microalgae biomass is produced in specially engineered facilities. Currently, open pond and photo bio-reactor (PBR) systems are the two most viable options for large-scale commercial production of algal biomass for biofuel. 

Open systems include raceway ponds, circular ponds and tanks. They resemble mostly closely the nature of microalgae and serve as the oldest and simplest systems for algal produetion. The simplicity lowers the production costs. An open pond usually is shallow (0.25-0.4 m deep) beeause optical absorption and self-shading by the algal cells limits light penetration through the algal broth." ... 

The comparison between open ponds and PBRs for microalgae cultivation is illustrated in Table 4.1. 

Schenk et al. (2008) mentioned that microalgae are among the most convenient sources of biodiesel due to their all-year-round availability. Microalgae cultured in an open pond was found to have a productivity that exceeds the yield of the best oilseed crops, producing 12,000 1 ha biodiesel compared with 11901 ha for rape-seed oil. 

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