Algae

 

Algae are the fastest growing photosynthesizing organisms, with growth cycles that reach completion in a few days. They rapidly fix atmospheric CO2 into biomass, reaching up to double their biomass every 24 hours (Christi, 2007). Of the many types of algae, green algae are the best at sequestering CO2 (Jackson, 1968).

 

 

Algae can be grown in photobioreactors, which are comprised of algae-filled glass tubes through which CO2 is bubbled. Algae grown in photobioreactors can then be harvested for biofuel production (Christi, 2007).

Algae

The image above shows the process by which the algae are transformed into fuel.  Algae are grown inside the polycarbonate tubes by pumping CO2 and other nutrients into the water and letting them absorb light to metabolize such compounds through photosynthesis and transform them into more complex molecules like oil.  The biomass is separated from the water through a physical process similar to centrifugation or sedimentation.  The water is then recycled through the reactor.  Oil is separated from the rest of the biomass through cell disruption and is then converted to biofuel through a process call transesterification, and the rest of the biomass is mostly converted into methane through anaerobic digestion.  The biofuel is then sold as fuel and the methane is used to supply energy to the reactor.  Any excess can be used for other purposes, such as animal feed, irrigation water, or fertilizer.

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Algae