Siemens Makes Algae Harvesting Easier

Siemens has devised a method of using magnetite micro-particles to "magentise algae". The algae envelop the magnetic particles, and are then easily separated from the aqueous growth medium using a magnetic field.

The researchers put magnetite particles in the water with the algae. The algae enclose these iron oxide particles, which are only a few micrometers in size. The resulting mixture of algae and magnetite can then be extracted using a magnet without having to drain the water— a major cost and time factor in other harvesting schemes.

The new technology offers numerous advantages, Siemens says, including less water loss and more efficient cultivation. The amount of algae harvested can be determined by varying the amount of magnetite used. A certain amount of algae is left behind as the starting stock for the next population.

So far the new technology has only been used on the laboratory scale, but the Siemens researchers are confident that it will also work on a larger scale. _GCC

Using a "racetrack" shaped growing pond with gentle circular current, the culture could be moved continuously through a magnetic extraction station -- for continuous harvesting.

Enough algae would remain in the brackish water or wastewater to keep the process going.

A lot of issues remain if algal fuels are to become economical on a commercial scale. Each remaining problem will be solved several ways, until more optimal economic approaches are devised. Industrial engineers understand this. College professors generally haven't a clue.