WSS Aims to Guard Vessel Efficiency Through "War on Soot"

WSS is urging ship operators to "wage war on soot" to minimise the risk of reduced EGB efficiency, costly cleaning, corrosion, and soot fires.

Wilhelmsen Ships Service (WSS) Thursday issued a call to ship operators to "wage war on soot," minimising the risk of reduced exhaust gas boiler (EGB) efficiency, costly cleaning, corrosion, and soot fires as a result of its accumulation in a ship's EGB.

"Just like any heat exchanger, an obstructive deposit will reduce the transfer of heat and therefore reduce the efficiency of the equipment," said Jonas Östlund, Product Marketing Manager for Marine Products and Oil at WSS.

"Soot deposits are particularly effective at reducing heat transfer as they insulate extremely well. A 1mm layer of soot can reduce EGB efficiency by 10 percent. Left to build up to a 3mm layer, EGB efficiency can be reduced by up to 50 percent."

Further, Östlund explains that cleaning of a typical EGB takes about five hours to clean at port every two to three months, requiring labour, equipment, and disposal of wash water.

"So, the cleaning task is more than a minor hassle – it's a major inefficiency, cost, and labour burden for the engine room," he adds.

Östlund also notes that cold corrosion can be a factor in EGBs operating at low velocities, as sulfur contained in the fuel reacts with oxygen during combustion to form sulfur dioxide and sulfur trioxide, after which, sulfur trioxide reacts with air moisture to form sulfuric acid in temperatures below 135°C, corroding tube surfaces.

WSS suggests that post-combustion fuel treatments, including its own Unitor's FuelPower Soot Remover Liquid Plus can prevent soot build-up and the many problems it causes.

WSS' says Unitor's FuelPower Soot Remover Liquid Plus, which is active from 180°C, is automatically dispensed as a fine mist four times per day, condensating onto the soot to oxidize it and preventing soot from depositing.

Östlund says a cost-benefit consideration shows that "the outlay is negligible when measured against the very real efficiency gains the treatment delivers. It amounts to less than half a percent of daily fuel cost."

In November, Ship & Bunker reported that Scientists from Lund University in Sweden said that particulate matter (PM) pollution from ships may be worse than previously thought.