MICRO ALGAE

Pond scum gets a bad rap. But microalgae — tiny, single-celled aquatic organisms — are rising stars in the renewable energy sector. They can provide oil that can be turned into liquid fuels such as biodiesel and jet fuel.

Algae oil is mostly triacylglycerides — long fatty acid chains with glycerol backbones — that can be converted to diesel and other fuels in relatively few steps. Algae’s potential lies in their speedy growth rate, efficient photosynthesis and flexible habitat preferences. Many strains can grow in saltwater or wastewater from treatment plants. In open ponds or closed bioreactors, the microorganisms can potentially make more than 50 times as much oil as land plants on the same area.

This potential fuel has a long history. In 1978 the Department of Energy launched the Aquatic Species Program to develop fuels from algae, but the program was shut down in 1996. In the intervening years, more than 3,000 strains were investigated, included species from Yellowstone National Park’s hot springs and the Caribbean Sea.

Now algae research is surging once again in both the private and public sectors. Problems still loom, including how to best extract the oil, scale up algae farms and control contamination by unwanted strains or tiny critters like rotifers that graze on the algal crop. But in June the algae-to-ethanol company Algenol Biofuels announced plans for a pilot plant with Dow Chemical Co. in Freeport, Texas. And in January, Continental Airlines conducted a 90-minute test flight of a Boeing 737 fueled in part by a blend derived from algae and Jatropha plants. Prospects for fuel from pond scum are starting to look up.

CARS stands for Carbon Algae Recycling System – a clever method of turning greenhouse gases, derived from tar sand processing, into clean-burning biofuels. The key to this waste-to-energy transformation is micro-algae, which naturally feed on byproduct CO2. The process is set to occur in man-made reservoirs, where algae do their work, then pass through the digester and eventually come out as fertilizer, biofuels and even nutritious foods.

“In essence, the goal of CARS is to fast-track Mother Nature’s own process of using plants to soak up greenhouse gases that would otherwise be released into the atmosphere,” says John McDougall, vice-chairman for I-CAN from the Alberta Research Council. “Other algae projects are aimed at creating biofuels. The goal of CARS is to provide industry with a sustainable, affordable way to deal with their greenhouse gas emissions.”

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