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on cruise vessels Retrofitting SOx scrubbers with confidence
Retrofitting SOx scrubbers with confidence
RETROFITTING A SOX SCRUBBER DEMANDS NOT ONLY CHOOSING THE RIGHT SYSTEM, BUT ALSO FINDING A SUPPLIER THAT CAN ENSURE A SUCCESSFUL PROJECT.
ALL IMAGES COURTESY OF ALFA LAVAL. T he task of choosing the right exhaust gas cleaning solution can be challenging, especially when it comes to a retrofit. Not only must the scrubber system meet the technical criteria, the supplier must also recognise the complexities of getting it on board; challenges which are compounded by the high intensity of the current retrofit period. A supplier’s reference list is a clear indication of experience. But while a list of systems sold has value, it means considerably less than a list of customers who have seen solutions in practice and are willing to endorse the result. “It’s always wise to look deeper into a supplier’s technical capabilities, global resources, logistics, processes, and best practices. Those things aren’t reflected in a list of systems sold”, comments Steven Pieters, Sales Director, Exhaust Gas Cleaning at Alfa Laval, one of the suppliers with the most scrubber retrofit experience.
Winning strategy A scrubber system consists of different components, the most important one being the scrubber body that is placed inside the funnel. Other equipment includes gas and water analysers, pumps, and GRE piping. In the case of hybrid or closed-loop systems, there is also equipment installed to clean the circulation water. The placement of the equipment in a retrofit project varies, depending on the available space on board. Alfa Laval has successfully completed more than 150 Alfa Laval PureSOx scrubber retrofits, at all major shipyards worldwide. This has given the team unique insights that are constantly applied to improve Alfa
A scrubber system consists of different components such as the scrubber body placed inside the funnel, gas and water analysers, pumps, and GRE piping.
Alfa Laval has successfully completed over 150 Alfa Laval PureSOx scrubber retrofits at all major shipyards worldwide.
Laval’s retrofit processes. “We’ve found that delivering PureSOx scrubbers as prefabricated components and modules is a winning strategy, as it saves time and work on board”, states Mr Pieters. “For faster installation, the scrubber can also be built into a new funnel on the shipyard quay and easily lifted on board.” Whatever the individual solution, planning and preparation are important. “Each installation has its own challenges”, adds Mr Pieters. “To minimise the vessel’s downtime, we usually perform some of the preparations while sailing.”
Tight cooperation A vital aspect of reducing downtime, overcoming obstacles, and guaranteeing success is ensuring a tight cooperation between supplier, ship owner, shipyard, and any engineering company involved. This is a matter of not only strong documentation, but also of communication and routines. “We appoint a dedicated project manager who takes responsibility for each retrofit. It’s important for that person to stay on top of the current status and conditions, which is why we emphasise having local project managers that are readily accessible and in easy reach of the yard”, explains Mr Pieters. “Each new project begins with a kick-off phase in which our dedicated project team aligns the goals with the customer. Throughout the project, we have regular status meetings to deal with anything that arises and ensure that everything is moving forward.”
Meeting requirements According to Mr Pieters, Alfa Laval’s welldeveloped processes are not only for efficiency, but also to ensure the expected results. “Through technical and practical measures, we can generally limit the total retrofit downtime to between two and four weeks. However, we also take full responsibility for seeing that PureSOx is in compliance, both through our commissioning at sea and by facilitating the class and flag state approvals.”
Decade of operating experience Alfa Laval’s PureSOx is a wet scrubber system that washes the exhaust gas stream by forcing it into contact with a liquid. In the case of marine SOx scrubbers, this liquid could be seawater, which is naturally alkaline, or fresh water mixed with an alkaline additive, usually caustic soda or magnesium hydroxide. When the exhaust gas is treated in a scrubber, the water >>
For faster installation, the scrubber can also be built into a new funnel on the shipyard quay and can be easily lifted on board.
Steven Pieters, Sales Director, Exhaust Gas Cleaning at Alfa Laval.
alkalinity converts the gaseous SOx into sulphate salt in a process called neutralisation. This sulphate salt, which is chemically different from SOx, ends up in the ocean through the scrubber water discharge. “Sulphate salt is not harmful to humans or the environment and there is already a large amount of sulphate salt naturally present in the ocean”, comments Mr Pieters. The SOx scrubber systems can be configured in three different operating arrangements: • Open-loop arrangement: seawater is used to scrub the exhaust gas and remove SOx. After passing through the scrubber, the wash water is legally discharged into the sea. • Closed-loop arrangement: the scrubber uses seawater or fresh water which is dosed with an alkaline additive and recirculated. As it becomes polluted, circulation water is cleaned, discharged and replenished to retain capacity. • Hybrid arrangement: this provides both open-loop and closed-loop modes. The mode can be switched at the push of a button.
“There are many good reasons to choose Alfa Laval PureSOx”, voices Mr Pieters. “We have more than a decade of operating experience at sea. The first PureSOx system on Ficaria Seaways has spent thousands of hours in compliant operation – and is still going strong. We also have an extensive global service network dedicated to helping our customers get the most from their PureSOx scrubber system. Our experts can be reached 24/7 for remote support and we have a large team of service engineers available in ample major ports, so help is never far away.”
