Stena Line Ferries First to Use New ‘Closed Loop’ Scrubber Technology

Stena Transporter is to be retrofitted with Wärtsilä in-line closed-loop scrubber systems. Photo courtesy Wärtsilä
Stena Transporter is to be retrofitted with Wärtsilä in-line closed-loop scrubber systems. Photo courtesy Wärtsilä

Two Stena Line ferries are set to become the first ships to be retrofitted with a new in-line closed loop gas scrubber systems from Wärtsilä that will help the ferries achieve emissions compliance in the North Sea.

Finnish power solutions provider Wärtsilä made the announcement Tuesday that the Swedish-based Stena Line has chosen the scrubber system retrofits for the ‘Stena Transit’ and ‘Stena Transporter’ ro-pax vessels, operating between Hoek van Holland in the Netherlands and Killingholme in the U.K. The order was placed with Wärtsilä in December 2014 and the retrofitting is scheduled to take place in Q4 2015 and Q1 2016.

The order marks the first for an in-line closed loop scrubber system, as the in-line option has previously only been available with open loop systems, Wärtsilä says. The compact design of the inline system saves space and also facilitates easier and faster installation, therefor reducing the time the vessel needs to be out of service for retrofitting, the company says.

The Wärtsilä closed loop scrubber system operates so that the wash water is being circulated within the scrubber. Exhaust gas enters the scrubber and is sprayed with sea water that has been mixed with caustic soda (NaOH), resulting in a reaction that neutralizes the sulphur oxides. The cleaned effluents can then be safely discharged overboard without causing harm to the environment.

The insallation of the scrubbers will ensure the ferries comply with the regulations covering emissions of sulphur oxides (SOx) while using conventional residual marine fuel (HFO). The operating routes of these two ferries fall within the North Sea’s Sulphur Emission Control Area (SECA).

“Wärtsilä was the first company to be awarded certification for marine scrubber technology, and we are the clear market leaders in this field. Our in-house know-how of engines, scrubber systems and marine applications is backed by our extensive resources and global reach. Furthermore, our extensive experience in retrofitting projects added considerable value to our engineering preparations for the project, and has thus helped the customer in their discussions with the yard. With the latest restrictions to sulphur emissions affecting more and more of the global fleet, our scrubber systems offer a competitive alternative to low sulphur fuels,” says Mr Juha Kytölä, Vice President, Environmental Solutions, Wärtsilä Ship Power.

“Stena Line takes environmental issues very seriously and the retrofitting of Wärtsilä scrubber systems to these vessels will significantly lower their environmental footprint. We are also, in cooperation with Wärtsilä and other partners, converting the Stena Germanica on the route Göteborg-Kiel to be run on Methanol, another step in our strive to achieve sustainable shipping. In the scrubber retrofit we are especially happy with the in-line option, which means that the retrofitting will take less time and allow the ships to be back in service with a minimum of delay,” says Mr Bjarne Koitrand, Technical Director, Stena Line.