All things considered

摘要

Although fuel prices have dipped, they are widely expected to rebound. So scrubbers, which strip exhaust gases of sulphur particles thereby allowing dirty HFO operation in ECAs, are still in contention. The German environmental organisation Nature and Biodiversity Conservation Union (NABU) estimates around 80 ships have already installed the systems, with up to 300 more on order, mostly on or for passenger vessels. Scrubbers can be divided into two types: dry and wet. The former use alkaline sorbents such as limestone to bind with the sulphur and form gypsum, while the latter bond the sulphur with water. Of wet scrubbers, there are a further three categories: 1. Open loop: which uses ambient seawater and where the sulphurous waste water is discharged overboard.