Algae Photo Bioreactors (APB's) are enclosed structures that utilise dense algal cultures to breakdown waste products and convert them into valuable by-products such as biodiesel and pharmaceuticals. It is extensively documented that algae, which are single celled plants, consume NOx and CO2 and produce O2 during photosynthesis. This process ensures carbon emissions are substantially reduced.

Algae are groups of relatively basic living aquatic organisms that capture light energy through photosynthesis, using it to convert inorganic compounds into organic matter. They vary from being microscopic single-celled organisms to complex multicellular plant species and larger Macrophytes such as seaweeds.

CO2 produced from the combustion of carbon compounds or from the aerobic digestion of organic carbon-based compounds are captured and directed into the Algae Photo Bioreactor. The transparent structure that contains the microalgae within a nutrient enriched liquid suspension is exposed to light (preferably sunlight although certain sources of artificial light may be utilised). This allows the algae to undergo photosynthesis and cellular division to take place. A dark phase is required as part of the algae's metabolic process and it is in this phase that the addition of nutrient enriched water and gaseous emissions which contain CO2 are introduced to the APB. Using sensors and computer controlled solenoids, algal density can be maintained at optimum levels, thus facilitating the highest possible uptake of nutrients that are introduced to the APB.

Algal Cake Processing

The algae grow very rapidly under optimal conditions and are eventually filtered from the system. The algae is dewatered, dried and then pressed to extract the cellular contents which may be suitable to produce biodiesel. In addition, the algal cake residue can be used for a variety of value-adding applications. The selection of "local" algae species is more advantageous over the introduction of an exotic species due to their adaptability to local environmental conditions.

Products that can be created from algae biomass include:

Mechanical pressing of dried algae for the recovery of oil used for biodiesel production;

Algae "cake" generated post-mechanical pressing utilised as carbohydrate feedstock for ethanol production;

Dried algae "cake" is an excellent source of protein, sold as fodder for livestock;

Hydrogen gas production;

Nutraceuticals (Astaxanthin, Chlorophyll, Beta-carotene)

Bioplastics;

Pharmaceuticals;

Fertilisers;

Health foods (Spirulina, Omega3).

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