Farming Fuels

In a few weeks the Algae Biofuels World Summit will take place in San Francisco, one of the first formalized events dedicated to the production of algafuels. Algae farming has garnered increased attention as oil prices continue to rise, and it is not surprising - they seem to outcompete their biofuel cousins on several fronts while having other added benefits.

Algae are miniature bio-factories, utilizing photosynthesis to transform CO2 and sunlight into energy. The primary interest in microalgae is their sheer efficiency in photosynthesizing - fundamentally doubling their own weight several times a day. One reason for this increased productivity is that up to sixty percent of an alga's body weight is already comprised of oil (oil palms, the largest biofuel producer yields approximately 20 percent of their weight). As such, algae are able to yield thirty times more energy per acre than corn or soybean crops, theoretically producing over 10,000 gallons of fuel per acre (recent closed loop systems claim to produce between 100,000 - 150,000 gallons per acre). To put this in perspective, soy produces 50 gallons of oil per acre per year; canola, 150 gallons; and palm, 650 gallons. Beyond its immense productivity, algae farms require no freshwater, consumable food, or arable land. Not only does this allow them to be placed virtually anywhere, it accounts for a lower production and maintenance cost than other biofuels, namely soybean and sunflower.

What is perhaps most appealing about all biofuels (including those from palm oil, soybean, and corn) is that they can be used in any engine that already consumes conventional petroleum diesel, eliminating the need for a separate infrastructural apparatus for distribution. Biofuels can also be blended with traditional diesel in any ratio, allowing them to slowly be introduced into the market as demand and algae farms grow. The infrastructure (and their associated costs) to service and distribute many new biotechnologies has often doomed their own development. This ability to colonize existing infrastructure allows for a seamless transition for both distributers and consumers of biofuels.

Between 1978 and 1996, the US Department of Energy funded several research initiatives focused on biofuel production including the use of algae farms. Scientists were successful at isolating 300 strains of the microorganism that were worthy of testing (in terms of their productive value) from a possible three thousand. With this research, new algae farms are employing high-yielding algae strains to increase efficiency. To further improve yields, ideal growing conditions become increasingly critical. Algae require high levels of CO2 (higher than what is currently in our atmosphere) for maximum production. A polyethylene ‘photobioreactor’ bag is frequently utilized to control light, temperature, nutrient and CO2 levels. The CO2 is often provided from coal power plants or other industrial processes, effectively cleaning the atmosphere in the midst of manufacturing biofuel. Further, the byproduct after extracting the oil can be used in cattle feed, vitamins and pigments.

The US consumes approximately 138 billion gallons of fuel a year. Given the yield of algae farms, The United States Department of Energy estimates that 9.6 million acres of land would need to be dedicated to algae farming - a mere fraction of the present 450 million acres of land devoted to agriculture. While algae farms can be located virtually anywhere, if they are strategically placed along waste streams, they could utilize either human or animal waste as a food source. Moreover, nutrients extracted from the algae (nitrogen and phosphorous) could produce organic fertilizers. This essentially creates a closed loop nutrient cycle from food to waste, to fertilizer and food. This would lower the consumption of petroleum-based fertilizers, treat waste streams, and create fuel. While biofuels may not require an infrastructural system, the siting of algae farms could take a regional infrastructural approach - located at key points in the agricultural and wastewater system to maximize yields while treating waste and consuming CO2.

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