Alfa Laval PureSOx exhaust gas cleaning system is gaining ground in the cruise ship market.
Royal Caribbean Cruises Ltd. has ordered four PureSOx scrubbers after a lengthy selection and qualification process. Alfa Laval’s PureSOx systems will be installed as retrofits aboard four Royal Caribbean International ships, three of the Freedom class and one of the Voyager class.
Royal Caribbean International ships Ltd. has as a mission the goal of reducing environmental impact.
‘SOx scrubber systems are part of our commitment to meeting or exceeding important environmental standards, as they allow compliance even where low-sulphur fuels have limited availability,’ said Harri Kulovaara, evp maritime at RCL. ‘We chose Alfa Laval and PureSOx on the basis of strong references, a strong technical platform and a strong willingness to cooperate in implementing the technology on our vessels.’
Alfa Laval’s scrubber technology meets the mission of Royal Caribbean International Ltd., which it shares with its fellow cruise operators.
‘RCL is a highly capable partner with a strong interest in seeing marine scrubber technology move forward,’ said René Diks, manager marketing & sales, exhaust gas cleaning at Alfa Laval. ‘Our collaboration on both the standard and inline PureSOx installations has been valuable for both parties.’
Although the solution fits the goal of reducing environmental impact, the implementation can be more difficult on cruise ships than on other vessels, especially when it comes to meeting space and stability limitations. Thus, a close dialogue between the two parties has been crucial for ensuring the best output. ‘There is immense complexity in a retrofit of this size aboard a cruise ship,’ noted Kevin Douglas, vp technical projects and newbuild at RCL. ‘To ensure the right solution and the smoothest possible implementation, we needed a thorough, open and systematic dialogue.’
Despite the space and weight issues, the standard U-shaped configuration of PureSOx was successfully incorporated into all three Freedom-class vessels. A flexible configuration reduced installation costs allowed multiple engines to be connected. The space for the scrubber was found behind the existing funnel, in front of the rock-climbing wall. Water cleaning unit and circulation tanks will be located up high on the same deck, this is to avoid additional booster pump.
Hybrid operation was especially important for RCL vessels, as is offers both closed-loop and open-loop modes. As the routes leads through US coastal waters, the vessels will adhere to US Vessel General Permit legislation, which sets stricter criteria than IMO.
‘Our cruise ships will naturally use seawater in open-loop mode whenever this is feasible,’ Douglas said. ‘However, their area of operations will require a closed-loop mode with reliable water cleaning. This is where Alfa Laval’s separation expertise comes into play.’
The PureSOx installation aboard Adventure of the Seas will also be a hybrid system. However, the design of this Voyager-class vessel posed additional constraints. Because the space available was even less and the stability issues even greater than aboard the Freedom-class ships, RCL was open to finding an alternative configuration. Adventure of the Seas will be the first vessel to install an inline version of PureSOx, which has been under development at the Alfa Laval Test & Training Centre in Aalborg, Denmark.
Inline scrubber configurations will be attractive or even necessary for many cruise ships and RoPax vessels, which is why inline development has been a high priority for Alfa Laval,’ said Jens Peter Hansen, Alfa Laval R&D manager. ‘The analysis and trials at our new test centre have focused on ensuring a safe water trap and minimizing material stresses in the inline design, because the scrubber is cooled and heated with every start and stop.’
This commitment from Royal Carribean International Ships Ltd. Double the number of cruise ships orders for Alfa Laval Pure Sox portfolio.