Motor fuels from Algae

 

Energy suppliers — including the world's largest, ExxonMobil — are working to produce motor fuels from algae, the stuff that resides atop stagnant ponds (and, in the news, off Alaska's North Slope). Algaculture is big business, with billions of dollars dependent on current research. It's hoped that within 5 to 10 years there'll be ways of transforming algae into gasoline, jet fuel and diesel competing in price with crude-oil-based counterparts. 

 

Photosynthetic algae exploit sunlight, thrive in brackish non-potable water and feed on CO2. In fact, production can be synergistic with coal-fueled power plants, the latter's CO2 emissions turned productively into algaculture feedstock. The bio payoff is high indeed: An acre of soybeans can yield 48 gallons of oil annually; algae are capable of producing an estimated 1200 to 10,000 gal./acre/year.

ExxonMobil is investing $600 million in a joint venture with Synthetic Genomics, Inc., a venture-backed company with expertise in genome engineering. One goal is to identify algae strains optimally producing lipids (greasy organic substances) that are refinery-ready. 

 

 

Other companies are interested as well. Royal Dutch Shell, second to ExxonMobil in global refining capacity, has had a joint venture with HR Biopetroleum in Hawaii since 2007. This demonstration facility is growing marine algae in open-air ponds, the resulting vegetable oil transformed into biodiesel. Another algae project was tested in Mexico's Sonoran Desert. Undertaken by Algenol Biofuels and Mexico-based BioFields, this one uses closed bioreactors that depend on algae, enzymes, CO2, sunlight and seawater. The bioreactors' output is fresh water, oxygen and ethanol, this last emitted in a continuous stream and said to be already yielding a rate of 6000 gal./acre/year. Algenol has recently formed a partnership with Dow Chemical to develop a $50 million pilot plant. 

 

If all these work out, just how much land would be committed to algaculture? To replace half of our conventional fuel, for example, researchers figure we'd devote some 13 million acres, about 4 percent of current cropland. (By comparison, to meet this same goal, corn-based ethanol would require 103 percent, more land than is currently farmed.)