Oil and walnuts on the menu in Geelong

Siemens has been contracted by the Shell Oil Company in Australia to deliver a revolutionary oil-water separation technology using black walnut shells.

Siemens Water Technologies General Manager, Tony Handakas, said bulk oil tankers unloading oil at the Geelong 'tank farm' located south-west of Melbourne are required to flush the ship's empty tanks with salt water prior to returning to sea.
"The oily salt waste water is captured and stored in large on-shore tanks for future disposal," said Mr Handakas.

"The Siemens Water Technologies offer to Shell was to filter the water and separate the oil allowing the clean salt water to be returned to the sea and the separated oil to be accumulated and reused."

The first stage of this clever filtration process pumps air into the oily water which carries the solids to the surface. Mechanical skimmers remove the oil from the surface of the water.

The less oily water is flushed through a porous black walnut shell filter. The filter is a deep bed of black walnut shells which have excellent surface characteristics for coalescence and filtration of oil.

The third and final stage of the filtering process involves two granulated and 'activated' carbon tanks. Activated carbon has tremendous surface area resulting from its porous structure. When flow conditions are suitable, the remaining oil in the water will flow over the carbon surface and stick to the carbon in a thin film while the water passes on.

"This filtration process is so effective it can allow the clean salt water to be safely returned to the sea without contamination," said Mr Handakas.
"The waste oil is then collected and accumulated in a separate tank and can potentially be on-sold for further refinement and use."
In this case, Siemens Water Technologies has removed a potential environmental contaminant from sea water while allowing recycling of a precious oil resource.

For more information contact Tony Handakas on +61 3 9721 7531 or by Email.