“We welcome serious new additions to the scientific literature related to exhaust gas cleaning systems, and this study by IVL, a well-respected research institute clearly makes some positive contributions.
First, it confirms the all-important exhaust emissions benefits of EGCS + HFO, concluding that EGCS are effective in reducing SO2 and particulate matter, including elemental and organic carbon. It also re-affirms that the emissions of SO2 and Total Hydrocarbons are much less than LSFO.
For water emissions, we do find some limitations and also inconsistencies between the executive summary and the main study. We are disappointed that the toxicity study only looked at washwater discharge samples, which would have included pollutants from the seawater source. We are also surprised the study only considered samples from three ships, and only one ship fitted with an open loop scrubber, which is not nearly enough to support the speculative conclusions in the executive summary.
For washwater quality, however, within the actual report IVL does show some very positive results. They found that most washwater parameters were in concentrations several magnitudes below the Environmental Quality Standards in the EU's Water Framework Directive -- this is consistent with other well-regarded studies by scientists in Denmark and Japan.
Apart from the toxicity section, which is too limited in scope and method, we believe that much of the IVL research is in line with other recent work and can be a useful addition to the existing literature."