This possibility of attaining self sufficiency in liquid fuels, as envisioned by Michael Briggs of the University of New Hampshire Biodiesel Group, has been brought a giant step foreword by the developments of GreenFuels Technology Corporation of Cambridge, MA.
GreenFuel's algae bioreactor system produces high-quality clean air biofuels™ from algae grown using smokestack emissions. The company claims that the fuels prices are competitive with conventional fossil fuel products. Biofuels are produced at the same time that emissions are being decreased. Using smokestack emissions as its feedstock, a site-configurable GreenFuel installation grows a year-round 'cash crop' of commercial grade algae. At the same time the process reduces the NOx by up to 86% and the CO2 by 40% of the smokestack emissions (2)
The system’s basic unit comprises a series of 8 foot (2.5 meter) tall bioreactors, in a unique triangle shape. The triangle legs are clear polycarbonate tubes 4 to 8 inches (10 to 20 centimeters) in diameter, through which water and algae are continuously circulated. The hypotenuse is oriented facing the sun to aid in photosynthesis, and the horizontal and vertical legs are often in the hypotenuse’s shadow. Fluid circulation (flowing through the lit hypotenuse, then the darker legs, and back to the hypotenuse) is balanced to provide optimum light exposure to the growing algae. Flue gases are pumped into the base of each triangle, and the algae removes the NOx and CO2 as the gas makes a single pass up through the triangle. The gases are not recirculated or cycled through more than one triangle.(3)
Since August 2004, the GreenFuel team has been growing algae on the flue gases from an MIT cogeneration plant, and harvesting algae ‘crops’ daily. Algae reduce NOx day and night, regardless of weather or lighting conditions. The process is essentially an effect of the surface configuration of the algae cell walls. Even dead algae can provide significant NOx reduction, up to 70 percent. The harvested algae can be used to generate renewable biofuel products, meaning an algae-based emissions reduction system could theoretically enable a power plant to meet emerging state regulations for both CO2 reduction and renewable power generation.(4)
During tests at MIT, the hypotenuse of the triangle was exposed to flue gas with approximately 13%. CO2 content. This CO2 is assimilated by algae which have been chosen according a protocol used by NASA. It is not a question of GMOs (genetically modified organisms), but rather of algae that have habituated to growing conditions. The gas cleaned by the bioreactor exits from the top, while a fraction of the algae is drained daily. The biomass thus obtained can be used to produce biodiesel, bioplastics, or molecules of pharmaceutical interest.(5)
According to Julianne Zimmerman, of GreenFuel management, "GreenFuel is working to deploy small scale field trials in the US in 2005 and 2006; we aim to commence operation of our first full-scale installations in 2008." An energy utility in the southwestern United States plans to roll out the system more broadly later this year. (6)
The 10-person company is still in its early stages. It has secured $2.1 million in venture funding and in March hired energy industry veteran Cary Bullock as president and CEO. GreenFuel's president Dr. Isaac Berzin admits, however, that the GreenFuel system isn’t a perfect fit for every plant. For one, the system requires unobstructed sunlight, which translates to surface area-in the case of even moderate size plants, the system would cover acres. But he says that a company survey indicates that about 70 percent of currently operating generating facilities have adequate land area available on their existing grounds.(6)
To further expand on possibility of attaining self sufficiency in liquid fuels the following is offered: To replace all transportation fuels in the US, we would need roughly 140 billion gallons of biodiesel. To produce that amount of biodiesel by growing soybeans would require almost 3 billion acres or over 1 billion acres growing canola (rapeseed), at nominal yields of 48 and 127 gallons oil per acre, respectively.(7) To produce that amount, by growing algae producing 15,000 gallons per acre, would require a land mass of roughly 9.5 million acres (almost 15,000 square miles ). To put these numbers in perspective, consider that the Sonora desert in the southwestern US comprises 120,000 square miles...450 million acres are currently used for crop farming in the US, and over 500 million acres are used as grazing land for farm animals (1). As has been shown here it is not possible to grow enough of the more conventional crops to meet our fuel needs, but using algae it is possible.
This example is not to be construed to mean that we have to switch all of our vehicles to diesel engines using biodiesel. Rather through conservation using hybrids and plug-in hybrids and more mass transportation, combined with use of ethanol and biodiesel there is a plausible roadmap to attaining self sufficiency. The Geenfuels system, the University of Wisconsin process for making alkane based biodiesel, and enzyme hydrolysis of carbohydrates in ethanol production all make producing large quantities of biofuels more likely than it was six months ago.
(1) University of New Hampshire Biodiesel Group
(2) GreenFuels Technology Company
(3) Power Engineering, November 2004, "Beta Test Set for Emission-Fighting Algae Bioreactor"
(4) Electric Light & Power, March 2005, "algae emissions reduction concept shows new promise"
(5) Biofutur no 255, May 2005, "An algae-based fuel"
(6) News.Com, May 20, 2005, "Start-up Drills for Oil in Algae"
(7) Journey to Forever, "Oil yields and characteristics".