MARPOL rule MEPC.1/Circ.642 , introduced in 2008, has allowed the recovery and reuse of the HFO fraction of waste oil as engine fuel. Alfa Laval’s PureDry separator allows vessels to recover practically all of their fuel oil losses, which range from 0.5 to 2% of their total fuel consumption.
PureDry is a hybrid technology: a high-speed, self-cleaning, disc-type centrifugal separator with a solid bowl. It requires no process water and leaves no liquid in the solid waste.
PureDry doe snot have a bowl aperture or hydraulics. The only major moving parts are an outer bowl and a separator insert, which rotate at slightly different speeds. Attached to the insert is the XCavator, a patented spiral device that transports the separated, super-dry solids into a container at PureDry’s base.
PureDry recovers virtually all of a vessel’s fuel oil losses with the ISO 8217 quality. The elimination of this energy leak has a strong environmental implication, but above all it makes sense from an economic standpoint.
Christer Karlsson of Norwegian Cruise Line, said: “Counting low, think something around USD 100,000 per vessel per year. With our fleet of around 15 vessels, that’s USD 1.5 million annually. Plus it has the advantage that we don’t have to land all that sludge.”
PureDry leaves just 5-10 kg of non-pumpable, super-dry solids per day, which are landed simply as dry waste. All of the water, with an oil content of approximately 100 ppm, is passed on to the bilge water system. This does away with the whole procedure of offloading waste to a barge.
“We don’t want to see any barges near our vessels except for the barges delivering fuel,” said MSC Manager Newbuilding Projects Giuseppe Gargiulo. “We believe this is an important step, even from an environmental point of view. We can now know exactly what we’re doing with all of our fuel, every bit. We can have the entire fuel process under control.”
May 27, 2014