Abstract: 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. A vertically-oriented gasser tube is provided. Gas is injected into this gasser tube along with the liquid nutrient medium. A bubble-size limiter is employed in the gas injector. The flow rates are configured so that the liquid nutrient medium and injected gas remain within the vertical gasser tube for 30 seconds or more.

Abstract: 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. A vertically-oriented gasser tube is provided. Gas is injected into this gasser tube along with the liquid nutrient medium. A bubble-size limiter is employed in the gas injector. The flow rates are configured so that the liquid nutrient medium and injected gas remain within the vertical gasser tube for 30 seconds or more.

Abstract: 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. A vertically-oriented gasser tube is provided. Gas is injected into this gasser tube along with the liquid nutrient medium. A bubble-size limiter is employed in the gas injector. The flow rates are configured so that the liquid nutrient medium and injected gas remain within the vertical gasser tube for 30 seconds or more.

Abstract: 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 is filtered and dried. Lipids are then extracted from the microalgae. These lipids are made into biodiesel through a trans-esterification process. The lipids may be used to make other products as well.