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EXHAUST GAS CLEANING SYSTEMS
With arguments raging over the merits of various exhaust gas cleaning systems, Clean Shipping International spoke with leading suppliers to gain their views on the best way forward
OPEN, CLOSED OR HYBRIDS? Setting the scene during recent conversations on the merits of various exhaust gas cleaning systems (EGCS) was Finland-based ship designer, naval architecture and marine engineering firm Foreship, which suggested that betterthan-expected return on investments from open-loop systems will translate into further orders once coronavirus-related uncertainties pass. Foreship’s scrubber selection recommendations to ensure ship emissions meet IMO2020 0.1% fuel sulphur content criteria are made totally independent and based on cost, complexity and vessel operating profile. With services ranging from feasibility studies to concept design, basic design, detail design and supplier evaluation, Foreship said that with around 60 exhaust gas scrubber references to date, the company has built up extensive experience of open-loop, closed-loop and hybrid systems, covering a variety of class rules and yard installations in Europe, North America and Asia.
C L E A N S H I P P I N G I N T E R N A T I O N A L – S p r i n g 2 0 21
Olli Somerkallio, Foreship’s chief operating officer, explained that the majority of the hybrid systems the company has worked on have been destined for cruise ships or ROPAX vessels, where vessels spend more time operating on coastal voyages and in port. However, lower cost open-loop scrubbers have represented a larger part of the company’s workload, with owners switching to lower sulphur fuels where port restrictions on washwater demand it. “It’s understandable that some local authorities take a negative view on acidity in washwater and the presence of heavy metals, no matter how low the concentrations, especially where water exchange rates are not high,” he said. “Hybrid scrubbers that switch to closed loop operations in port certainly provide one option but the other remains to install an open loop system and manage a switchover to low sulphur fuels in port.” Somerkallio said that the combination of covid-19 and cut-throat oil pricing has eaten
