Algae: Pond Powered Biofuels

D. Wogan, A.K. da Silva, M.E. Webber, and E. Stautberg, November 2008 (Citation)

Abstract

The US is the world’s largest energy consumer, which results in adverse effects on the climate, overdependence on foreign oil and economic uncertainties. To mitigate these harmful effects, biological alternatives to fossil fuel sources are being investigated. Biofuels today are primarily produced from first- generation feedstocks such as corn, sugarcane, soybeans and rapeseeds. Unfortunately, reliance on crop- based feedstocks has led to problems such as land depletion, continued fossil fuel usage, competition with food, and increased water use. Algae, on the other hand, are an appealing feedstock for next-generation biofuels because they can make use of natural or underutilized resources, can be produced domestically, consume carbon dioxide via photosynthesis and have the potential to displace fossil fuel usage in an environmentally sound manner. Therefore, finding ways to overcome the technical, economic, cultural and policy barriers to the use of algae for biofuels production presents a compelling opportunity for society.

Algae are simple unicellular organisms that produce carbohydrates, proteins and lipids as a result of photosynthesis. Sunlight, water, nutrients and arable land are the major requirements for growing algae. Thankfully, the water can be brackish or saline, thereby avoiding competition with freshwater resources, and the land can be non-arable, avoiding competition with food production. The products of algae growth can be used for many different fuels: lipids can be processed into chemical feedstocks, biodiesel or jet fuel; biomass can be fermented into ethanol, anaerobically digested to produce methane, or burned directly for power generation; or simply used as a carbon sink. Compared to terrestrial crops, algae utilize solar energy more efficiently and because they are not limited to one growth cycle per year, they can be harvested much more often.

Texas presents a unique opportunity for algae production because it contains the basic resources needed to grow algae in abundant quantities: Texas produces over 170 million metric tons of CO 2 annually (more than any other state, and ahead of all but 6 countries); contains abundant saline and brackish aquifers; receives abundant sunlight; and has an impressive knowledge base and technical expertise within the energy and refining industry. Additionally, as one of the largest producers of energy in the world, Texas has an incentive to produce the next generation of fuels. These qualities make Texas an interesting case study for the growth and production of algae for biofuel use on a large scale.

Algae as a biofuel feedstock have garnered much interest in the venture capital, investment, and research arenas with many companies, universities and laboratories leading research efforts. The rise in investments has increased yearly and is a promising sign that algae-based biofuels have the potential to contribute to our nation’s energy portfolio. Research areas include genetic modification of algal species for efficient sunlight utilization or producing specific hydrocarbon chains for direct processing into gasoline, diesel and jet fuel. Varying levels of success have been achieved by companies and research labs but none have succeeded in producing algae oil on a scale sufficient for meeting US transportation requirements. To understand the long-term planning and other issues, accurate and objective assessments are needed to assess the feasibility of algae growth.

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Citation

D. Wogan, A.K. da Silva, M.E. Webber, and E. Stautberg, “Algae: Pond Powered Biofuels,” Clean TX Forum, Austin, TX, November 19, 2008.