Open loop exhaust gas cleaning system, a deep analysis of effects produced by its residual waters

Abstract

New regulation implemented through Marpol Convention on its Annex VI has come into force on 01st January 2020. We are talking about a new sulphur cap in fuels used by ships which is established in a 0.5% mass/mass. We can find this regulation, in Marpol Convention, on its Annex VI, regulation 14.1.3. To follow this new regulation, some shipping companies are investing in the installation of exhaust gases cleaning system, commonly known as scrubbers, on board their ships. There are three different systems, open loop, close loop, and hybrid. We are going to focus and break down the open loop method. Open loop exhaust gases cleaning system discharges overboard the residual water used during the cleaning process of exhaust gases from ship engines once that water has been analysed by the system. The aim of this analysis is to make sure that water follows all parameters and caps regulated in a resolution from Marine Environment Protection Committee, specifically the MEPC.259(68), before this water is being discharged overboard. Water parameters regulated by Resolution MEPC.259(68) are acidity (pH), Polycyclic Aromatic Hydrocarbons concentration (PAH), heavy metal/ashes concentration (turbidity) and nitrates concentration without forgetting the wash water additives and other substances used in exhaust gas cleaning systems.