Available Technologies

Technology

In accordance with the Energy Independence and Security Act of 2007, a minimum of 36 billion gallons of biofuel should account for transportation fuel sold annually in the U.S. by 2022. Twenty-one billion of these must be derived from non-cornstarch products. Microalgae have become a promising biofuel source due to their incomparably high oil content and minimal space requirements. Unfortunately, harvesting and concentrating algal biomass for oil extraction can be difficult.

Algae are typically grown in suspended form, and current harvesting methods generally require separating the algae from their growth medium. The literature suggests that up to 30% of the total algal biodiesel production cost is due to biomass harvesting. Conventional techniques like centrifugation have high capital and operational costs, while techniques like flocculation require expensive chemicals and have slow sedimentation rates.

Researchers at UAH have developed a harvesting technique that does not require specialty chemicals or equipment and demands little energy. The algae are harvested directly from their growing environment suspended in liquid culture. This technique is fast, and the entire harvesting process can be done in under a minute. The harvested algae contain only ~4 percent water and involve no heating or centrifugation. The chemicals used are all environmentally friendly and non-toxic.