The Clean Shipping Alliance (CSA) has defended the use of exhaust gas cleaning systems (EGCS, or ‘scrubbers’) against recent claims made by environmental lobby group Opportunity Green.
An article by Opportunity Green published in maritime paper Tradewinds has been dismissed by CSA as ‘opinion rather than science’. CSA points out that scrubbers have been in use globally for some 50 years, and there has been no valid scientific research to show that operation of scrubbers has in any way harmed the marine environment. Instead, scrubbers have enabled many ship operators to more than fulfil the IMO’s sulphur emissions regulations.
According to CSA, the chemical process in EGCS that removes sulphur oxides from the exhaust mechanically removes 60% to 90% of particulate matter and reduces visible smoke. Levels of particulate matter from scrubber-equipped ships burning HFO are below those from non-scrubber equipped vessels burning VSFO, while the ultra-fine particles, which are particularly harmful to health, are virtually eliminated.
The capability of EGCS in removing particles is considered to be one of the main reasons for Marpol Annex VI, the EU Sulphur Directive and the US Vessel General Permit all endorsing the use of scrubbers. Emissions of black carbon have been highlighted as a negative effect of EGCS, but CSA maintains that this is part of the particulate matter removed by EGCS, and has no special connection to scrubber use. Similarly, the tiny increase in CO2 emissions due to increased power used by scrubbers is believed to be significantly less than the well-to-wake CO2 penalty from using distillate fuels.
CSA Executive Director Andreas Chrysostomou said: “The bottom line is that scrubbers continue to contribute globally to significantly improved air emissions quality through both greatly reduced sulphur and particulates.”
Image: Andreas Chrysostomou (source: Clean Shipping Alliance)
