The International Maritime Organisation (IMO) directive will reduces the maximum sulphur content of marine fuels from the current 3.5% to 0.5% by January 2020 (subject to 2018 review).As an alternative to low sulphur fuels, ships can option for equivalent compliance methods such as exhaust gas cleaning systems. The most common EGCS system are the wet-closed/open loop scrubbers. The scrubber sizing criteria come from the chemical engineering theory for land-plant (Flue Gas Desulphurization-FGD). However, the application of such criteria cannot always applied in the naval field, where the problematic is the same, but the boundary conditions are completely different. Consequently, the scrubbers for naval applications on the market generally operate with high liquid-to-gas ratio, resulting in very high water flow rate associated to large pumping group in size and high pumping energy costs. Moreover, is widely acknowledged that the standard scrubbers are not able to capture fine particles (>0.5 μm).
Thanks to the experience acquired within the DEECON project, VTS and University of Naples UNINA are working on the design and testing of an industrial scale Electrostatic Sea Water Scrubber (ESWS) to operate on a naval Engine of 1.5MW under the project RAIN. The ESWS is a conventional scrubber where both droplets and gas phases are charged/ionized in order to enhance the abatement efficiency of the particulate matter and soluble gas. The aim of the RAIN project is the development of the Electrostatic Sea Water Scrubber to drastically reduce the amount of water consumption, assuring the SO2 abatement >96.6% and the fine/ultrafine particle (>0.02 μm) higher than 90%.