Impressive Oil Yields from Australian Algae

The race is on for microbe biofuels. Algal oil has the potential to out-produce all other oil crops, but several technical challenges keep the costs of production relatively high.

Compared to soybeans that produce 50 gallons of oil an acre a year, some algae can average 6,000 gallons -- but it's not cheap to produce. Current algae growing methods use ponds and bioreactor columns, and algae float around suspended in water. Harvesting such a moving target systematically requires using very costly inputs like centrifuges and electricity. Even with these best technologies for algae growth and production, the end product biodiesel is expensive at about $56 a gallon. _Bioenergy

Researchers in Australia are leading the race in open pond production of algal oils -- they are producing at the rate of 2900 gallons per acre per year, on open ponds.

The project is working simultaneously on all steps in the process of microalgal biofuels production, from microalgae culture, harvesting of the algae and extraction of oil suitable for biofuels production, said Professor Borowitzka.
Based on current results, construction of a multi-million dollar pilot plant to test the whole process on a larger scale will begin in Karratha in the North-West in January and is expected to be operational by July.

Borowitzka said that the project has achieved production rates of 50 tonnes of algae per hectare per year (20.2 tonnes/acre), more than half of which is converted to oil. At 50% oil content (10.1 tonne/acre), that would work out to approximately 2,900 gallons·ac-1·yr-1.

These high production rates are expected to increase at the new pilot plant due to the even better climatic conditions in Karratha.

—Michael Borowitzka __GCC

While some researchers focus on achieving maximum production from open ponds, others are working toward similar goals for closed loop production of algal oils. Meanwhile, engineers and scientists are devising ways to pare down the costs at each stage in production. This research is taking place on all continents and in virtually all developed nations.

The Perth researchers have already beaten other methods of bio-oil production in terms of volume per year -- and they are just getting started. With the attention algae is receiving, we are on schedule for commercial production within 10 years and significant displacement of petroleum within 20 years.