FEBRUARY 17, 2015 — Two Stena Line Ro-Ro ferries are to be fitted with the first in-line closed loop exhaust gas scrubbers to be ordered from Wärtsilä. As part of its contract Wärtsilä will, in addition to the scrubbers, also supply engineering support, technical advisory services, and commissioning of the systems.
The two ships, the Stena Transit and Stena Transporter, operate between Hoek van Holland in the Netherlands and Killingholme in the U.K. in the North Sea Sulfur Emission Control Area and by installing the scrubber systems they will be able to comply with the SECA limits on SOx emissions while using conventional residual marine fuel (HFO).
The in-line scrubbers chosen for the two ships save space and facilitate easier and faster installation, but had previously only been available in an open loop system.
In the Wärtsilä closed loop scrubber system, exhaust gas enters the scrubber and is sprayed with sea water that has been mixed with caustic soda (NaOH). The sulfur oxides in the exhaust react with this mixture and are thereby neutralized. The cleaned effluents can be safely discharged overboard without causing harm to the environment.
"Wärtsilä was the first company to be awarded certification for marine scrubber technology, and we are the clear market leaders in this field," says Mr Juha Kytölä, Vice President, Environmental Solutions, Wärtsilä Ship Power. "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 shipyard. With the latest restrictions on sulfur emissions affecting more and more of the global fleet, our scrubber systems offer a competitive alternative to low sulfur fuels."
"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 [see earlier story]. 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.