Page 28: of Maritime Reporter Magazine (July 2014)

28 Maritime Reporter & Engineering News • JULY 2014 expensive heavy fuel which means installing a scrubber systems.

Each of the solutions have their pros and cons, and at this stage it is not possible to make a fair comparison, particularly given the historical and likely future fl uc- tuation in fuel pricing. But in the big picture, the fuel price certainly has a considerable effect on the decision.

With respect to the scrubber solution Wärtsilä says “this leads to the lowest lifecycle-costs, however the amortization depends of the price differences between heavy fuel and gasoil with a low sulfur content of 0.1 percent.”

Development of Scrubber at Wärtsilä

Wärtsilä has a long and noted history in the develop- ment of its scrubber system, which was working as a closed loop systems with freshwater and caustic soda. In fact it was a pioneer among engine manufacturers in the ability to supply certifi ed equipments.

After Wärtsilä took over Hamworthy it was then able to own a scrubber system which works on a open loop method, without any chemical additives, operating with suffi cient alkaline seawater. The decisive factor for the use of the open loop system are the alkaline properties of the respective seawater. If this is not suffi cient, a hybrid system must be used. Indeed, this is a fl exible, but at the same time also a complex and corresponding solution, which is only relevant for vessels whose area shows big differences in respect to the alkalinity of the seawater.

As of March 2014 Wärtsilä had goods on order to equip 45 vessels for a total of 94 exhaust gas cleaning systems for both newbuild and retrofi t projects –representing more than one-year of production.

The Color Line Decision: Seawater

Color Line opted in favor of scrubbers, which oper-

MARINE PROPULSION

Left

Wärtsilä In-Line Scrubber for new buildings and retrofi t installation.

Below

Wärtsilä Open Loop Scrubber System works with seawater.

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