Wärtsilä provides hybrid scrubber system solutions which have the flexibility to operate in both open and closed loop using seawater to remove SOx from the exhaust. This provides a flexibility of operation in low alkaline waters, as well as the open ocean.
When at sea the switch can be made to open loop using only seawater. The sulphur oxides in the exhaust react with the water to form sulphuric acid. Chemicals are not required since the natural alkalinity of seawater neutralizes the acid. When required to switch to closed loop, for instance whilst entering a port in a low alkalinity area, the natural alkalinity of seawater is boosted by an alkali which uses caustic soda (NaOH) as a buffer.
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