Floating Plastics Help Create Alternative Fuel

NASA is developing a technology that uses large arrays of plastic tubes that float in seawater and contain algae that can be converted into fuel.

The floating algae cultivation system, called Offshore Membrane Enclosure for Growing Algae (OMEGA), is designed to grow freshwater algae in municipal wastewater using photobioreactors, or flexible plastic tubes. NASA has spent $10 million on the project because it is looking into alternative sources for aviation fuel.

The algae treat the wastewater by consuming nutrients that, if released into large coastal waters, could create algal blooms that consume oxygen. As the algae grow, they absorb carbon dioxide and release oxygen.

Algae can double their numbers and be ready to harvest in three to five days. After the oil is removed from the algae, the remnant material can be used to produce fertilizer, natural gas, and animal feed.

The system has its challenges, reports Geek.com. For example, to produce 2.4 million gallons of algae for fuel use, a two-square-mile area would have to be covered with the plastic algae incubators. NASA claims that its system can produce more than 2,000 gallons of oil per acre, compared with 600 gallons from palm and 50 gallons from soy beans, reports Energy Digital. In contrast, jets use several hundred to a few thousand gallons of fuel per hour of flight.

Another factor to consider is the amount of energy needed to make the plastics, whose major components are oil, for the algae system versus the energy the system could create from its oil production. Yet another challenge is what one could do with the plastics after they have been used. Would they be put in a landfill or recycled?

Source: “NASA Invests $10 Million in Energy-Producing Floating Algae Bags,” Geek.com, 4/13/12
Source: “NASA Showcases Innovative Method to Grow Algae-Based Biofuels,” NASA, 4/17/12
Source: “Turning Algae Into Oil the NASA Way,” YouTube