Microalgae algal production systems

Table 4 3 Examples of algal production systems used for the most popular microalgae genera in aquaculture, i.e. Nannochloropsis spp., Isochrysis spp. and Chaetoceros spp., and associated productivities... 

In order to assess the volumetric productivity of the system the micro-algal biomass concentration and average specific growth rate need to be known. For the moment it will be assumed that the biomass concentration can be set at any desired level by means of a turbidostat mode of operation. Consequently, only the average specific growth rate of the microalgae in the photobioreactor needs to be calculated. 

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." ... 

Feasibility of growing on nonarable lands microalgae cannot be cultivated directly in soil, and many nonarable lands could be exploited for algal mass cultivation. Microalgae can utilize various wastewaters and seawater, which cannot be used for agricultural systems. This may reduce the competition between food crops and biofuel production. 

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