Space Efficient Photobioreactor System

The continued use of petroleum-derived fuels is now widely seen as unsustainable. Presently available biofuels can be substituted for petroleum-derived fuels without the need for extensively modifying existing internal combustion engines.

The present invention describes a microalgae-based bio-fuels production system in a space efficient photo-bioreactor. The bioreactor grows microalgae in a tall array of transparent flooded tubes. A nutrient media is circulated through the tubes. The array is configured to maximize the amount of sunlight falling upon each tube so that growth of the microalgae is as uniform as possible. Gassing/degassing systems are attached to the array of tubes at appropriate locations. These introduce carbon dioxide and remove oxygen. Cooling systems are preferably also provided so that the circulating media can be maintained at a desired temperature. Microalgae are harvested from the photo-bioreactor. The microalgae are filtered and dried. Lipids are then extracted from the microalgae. These lipids are made into biodiesel through a trans-esterification process and can be used to make other products as well.

Advantages:

• Compact microalgae cultivation in a high productive manner
• Reduces the need for land since it has the potential to provide higher biomass production density than traditional systems of microalgae biomass production
• The modular conception allows for the gradual implementation of the system for in situ biofuel production wherever it is needed