Biodiesel from algae goes with the flow

Biodiesel from algae goes with the flow

Researchers at United Environment and Energy in Horseheads, New York, say they have developed the first economical and environmentally-friendly process to produce biodiesel from algae. Ben Wen and colleagues' flow fixed-bed reactor technology is 40% cheaper than existing techniques and is faster too. It relies on using a new solid catalyst developed at United EE.

Methods for producing biodiesel from algae have not changed much over the last twenty years and are often expensive, inefficient and rely on toxic alkali liquid catalysts. Waste water is also produced. The new technique developed by Wen and co-workers overcomes these problems thanks to a proprietary solid catalyst.

The catalyst, which is made of mixed metal oxides, allows a continuous flow of biodiesel to be produced, unlike in the case of liquid catalysts that need to be neutralized with acid after each batch. No such treatment is needed for our catalyst, explains Wen, and algae oil and methanol are input from the inlet of the reactor and flow out of the reactor as biodiesel and glycerol. The continuous flow method could also be easily scaled up or down depending on the size of the production plant and might even be used in the field if portable devices were to be made.

Wen estimates that algae can produce 100-300 times more oil per acre than soybeans and thus are the most promising candidates for mass-producing biodiesel in quantities large enough to entirely replace transportation fuel in the US. Indeed United EE is currently conducting a pilot program that could produce nearly 1 million gallons of algae biodiesel per year. "Depending on the size of the machinery and the plant, it is possible for a company to produce up to 50 million gallons of the fuel annually using a small plant," he said.

Wen adds that United EE is the first to work on fixed-bed algae biodiesel production. Algae are also plentiful and grow abundantly in oceans, rivers and lakes throughout the world, and are not a primary food source for humans - unlike soy or palm oil.

The next challenge for the researchers is to get hold of large quantities of algae oil, since only limited supplies are available at the moment around the world.

The work was presented at the last meeting of the American Chemical Society in Salt Lake City.
About the author

Belle Dumé is a contributing editor to environmentalresearchweb.