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07.11

Biofuel — A Viable Solution Engineered from Algae

Increasing Demand for Oil

At the end of 2006, worldwide oil consumption was in excess of 31 billion barrels per year. During that year, the U.S. consumed 7.55 billion barrels. With limited domestic sources of crude oil, the United States was forced to import 4.9 billion of those barrels (65 percent). According to the Energy Information Administration, world consumption of oil rose by 1.63 percent annually for more than 20 years. Recently, however, the rate increased as China and India’s consumption has grown at 7.5 percent and 5.5 percent annually, making them the world’s first and fifth largest consumers of oil, respectively. By the year 2020, oil consumption is projected to increase by 60 percent.

Decreasing Supply of Fossil Oil

In order to produce oil from fossil oil wells, it first needs to be discovered. The peak of world oil field discoveries occurred in 1965 at around 55 billion barrels per year. The rate of oil discoveries has been declining steadily since that time. Between 2002-2007, less than 10 billion barrels per year of oil were discovered. Also, new discoveries are often in areas where extraction is much more expensive, such as extremely deep wells, extreme down-hole temperatures and environmentally sensitive areas where expensive technology is required to extract the oil. Additionally, many of the world’s remaining reserves are in unconventional, hard to extract forms such as oil shale or tar sands. Experts agree that the world has reached or will soon reach its peak oil production. This means production levels will wane and ultimately fall.

Mandates for Sustainable Energy

Increasing demand for energy, diminishing fossil fuels, global warming along with the growing security and economic risks of supporting Middle East oil have set the stage for domestic green energy. The U.S. government, the military and commercial sectors are all looking for ways to transition to alternative energy. Although billions have been invested in this area over the past decade, there is no viable commercial green solution that can compete with the portability, energy density and availability of petroleum products. The closest are corn- and soybean-based ethanol and biodiesel biofuels. Costs in labor and natural resources like water are alarmingly high, while energy density is low and ultimately divert food products from consumers. On the other hand, in the right growth environment, microalgae doubles biomass on a daily or weekly basis and produces energy-dense oil with a comparatively low overhead in manpower, water and other commodity resources. While algae grow, they recycle carbon dioxide (a greenhouse gas) for cleaner air and carbon credits. What was missing until now was a commercially scalable, high-capacity algae cultivation technology that yields competitively priced fuel production.

Why Algae?

Algae production has the potential to outperform other biodiesel products such as soy or corn. The production of biocrude oil and biodiesel from microalgae is significantly more efficient than the production of fuel from food crops. Unlike soy, which produce approximately 70-100 gallons of biodiesel per acre per year, or corn, which produce 150-300 gallons of ethanol per acre per year, algae can produce in excess of 10,000 gallons per acre per year of raw biocrude oil.

By growing a variety of algae strains and species, numerous renewable biofuel products can be produced — specifically a true biocrude algae oil, a biodiesel feedstock algae oil, butanol, and other chemical precursors required for high-performance fuels.

The true biocrude oil is a light, low-sulfur, high-quality petroleum oil product that may be hydrocracked in an oil refinery to produce many high-quality lower-weight products such as gasoline, kerosene and diesel. The biodiesel feedstock oils are high-quality lipids that may be substituted for soy oil (or other seed oils) in biodiesel refineries. Butanol is a well-known high-quality biofuel candidate that has properties similar to gasoline, it is mixable in any proportion with gasoline for use in standard combustion engines, and is readily applicable to the jet fuel market as well. In addition, other chemical precursors are produced to feed existing commercial processes to make components of high-performance ASTM certifiable fuels, including general aviation fuels and turbine engine fuels.

Further, the microalgae cultivation process has the advantage (over petroleum production from deep wells) of consuming atmospheric CO2 thereby creating the opportunity to participate in a carbon credit or "cap and trade" markets where they exist. Also, the residual biomass contains significant energy and useful chemicals in the proteins, sugars and starches. This biomass can be used to produce high performance fuels, as well as for recovering valuable fertilizer components.

 Growing Methods

Algae can grow over a wide climate range. To yield maximum results, specific growth conditions are needed, such as low UV-B radiation levels, moderate temperatures, managed light levels and access to fresh water supplies.

The most common method of microalgae cultivation for biodiesel production is through open-pond growing. The drawbacks of this method include excessive sunlight exposure, inclement weather and contamination from other strains of algae, bacteria and molds. Large-scale production due to contamination losses may be cost prohibitive.

Closed production systems (photo bioreactors) have been constructed to grow algae under ideal conditions. However, most of these systems are cost intensive with no proven pathway to scaling to commercial production levels.

Vertical — vineyard like — growth systems have been developed to produce and cultivate microalgae more efficiently and cost effectively. These systems consist of algae growing in clear, plastic-film tubes. The tubes are arranged so they receive optimal exposure to sunlight. The proper exposure increases the growth rate, while the tubes protect the algae from contamination.

The vertical vineyard growing methods represents a scaleable, high-productivity microalgae cultivation technology and has solved the key challenges for feasible production of superior fuels derived entirely from microalgae biomass.

Twenty-First Century Farming

By approaching algal growth technology with the precision and insight of engineers, the vertical vineyard growth method is pioneering clean energy and reinventing farming. Use of farm logistics, know how, business models and infrastructure provides a fertile opportunity for adoption of these new valuable farm methods and products.

Engineering a practical approach to farming that produces high-yield, low-cost alternative energy.

References

“Petroleum production and consumption statistics,” Energy Information Administration (EIA), U.S. Department of Energy (DOE), Web Page. [Online]. Available: http://www.eia.gov/dnav/pet/pet_sum_snd_d_nus_mbblpd_a_cur.htm

“Biodiesel overview,” Energy Information Administration (EIA), U.S. Department of Energy (DOE), Monthly Energy Review, March 2009. [Online]. Available: http://www.eia.gov/FTPROOT/multifuel/mer/00350903.pdf

L.W. Hillen, G. Pollard, L. V.Wake, and N. White, “Hydrocracking of the oils of Botryococcus braunii to transport fuels,” Biotechnology and Bioengineering, vol. 24, no. 1, pp. 193–205, 1982. [Online]. Available: http://dx.doi.org/10.1002/bit.260240116

Y. Chisti, “Biodiesel from microalgae,” Biotechnology Advances, vol. 25, no. 3, pp. 294–306, 2007.

“Official Energy Statistics from the U.S. Government.” [Online]. Available: http://www.eia.doe.gov

B. Tao, Shawn P. Conley. What is biodiesel? Technical report, Department of Agronomy, Department of Agricultural and Biological Engineering, Purdue University, http://www.extension.purdue.edu/extmedia/ID/ID-337.pdf, 12 2006.

Pimentel, David. “The Limits of Biomass Energy.” Encyclopedia of Physical Sciences and Technology, September 2001. [* up to 328 gallons of ethanol per acre.]

J. Sheehan, T. Dunahay, J. Benemann, P. Roessler, and J. Weissman. A Look Back at the U.S. Department of Energy’s Aquatic Species Program: Biodiesel from Algae; Close-Out Report. Technical Report NREL/TP-580-24190, National Renewable Energy Laboratory, U.S. Department of Energy, 1617 Cole Blvd., Golden, CO, 80401-3393, July 1998.

William R. Kassebaum, P.E., is president and CEO of Algaeon, Inc., a company developing algae cultivation methods and biofuel production. He is a Senior Member of the IEEE and serves as chair of the Central Indiana Section (2006-present), co-chair of the Central Indiana Engineering Consultants’ Network, and chair of the coordinating committee of the IEEE-USA Alliance of IEEE Consultants’ Networks (AICN).

Algaeon, Inc. is focused on the development of industrial scale micro-algae cultivation technology for the production of 100 percent renewable and sustainable drop-in replacement biofuels. Our goal is to reshape the competitive energy landscape by providing a new domestic source of eco-friendly renewable energy.

Comments may be submitted to todaysengineer@ieee.org.