The use of scrubbers or a fuel switch from HFO to MGO when entering an emission control area (ECA) is[ds_preview] an important choice for shipowners, taking into account the costs and the operational flexibility. Norwegian-German classification society DNV GL has worked on that issue too and has recently awarded the first »Scrubber Ready« notation when Unique Shipping christened the 84,000m3 LPG carrier »Oriental Jubilee«. »Unique Shipping has been a very important partner for us at DNV GL, in providing feedback throughout the development process of our new rule set and particularly for the development of the notation. So it was only natural that a vessel from Unique Shipping would be the first to be awarded the DNV GL notation«, said Ole Gilså, Area Manager Ulsan at DNV GL – Maritime.
When the 0.5% sulphur cap will be introduced in 2020 or 2025 up to 70,000 ships may be effected. So far, most ship owners have opted for fuel switch, but that would not be the best option for all ship types. The data of the classification society show 313 scrubber projects conformed so far. More than half of them refer to cruise vessels and passenger ferries (126) or RoRo ships (69), because these have fixed trade routes in ECAs and higher fuel consumption because higher electricity consumption. In that case scrubbers could lead to fuel savings of 45% compared to fuel switching, DNV GL estimates. Currently, hybrid scrubber are most popular, followed by open-loop systems.
According to the classification society, the »Scrubber Ready« notation takes into account all the relevant factors for the installation of scrubbers, ranging from space and stability requirements to fire safety, piping, corrosion resistance and the effect on the main engine. »This helps to reduce off-hire time and retrofitting costs if a scrubber system is fitted in the future«, it was announced. DNV GL also offers scrubber advisory services to support customers, from building the business case, to risk assessment of the design, installation, commissioning, hardware-in-the-loop testing of the control system, right through to the system entering into operation. »Oriental Jubilee« and its sister vessel, which is scheduled for delivery in September 2017, have been prepared for the installation of a hybrid scrubber system based on an existing design and technology. The unit can also be connected with multiple exhaust gas inlets from the ship’s main engine, three diesel engines and the boiler. Swee Yin Wong, Senior Surveyor at DNV GL’s Ulsan station in Korea, said, »The system enables wash water to be discharged into the sea in open loop mode, but also includes a liquid recirculation system in order to operate in closed loop mode. This is important if you operate in fresh water or low-alkalinity areas, as well as in areas, where discharging wash water is prohibited.« DNV GL has performed partial or full Technology Qualification Processes (TQP) for six of the largest scrubber suppliers.
