Scrubber – is a self-purifying system able to burn HSFO (sulfur max 3.5%) and reduce the sulfur content to max 0.5%. They are mainly used by ships (like Container ships or Cruise ships) where the rotation of the port is pre-decided. [Remember to check out our quick-reference guide if you're not familiar with any of the abbreviations and terms in our blogs]
Today, the price difference between HSFO 3.5% max and VLSFO 0.5% max is around 100~110$, meaning that a scrubber equipped vessel will pay 100-110$ less per ton. This can amount to a very large difference in overall operating cost. For example, if a vessel takes 1000 mt every month, there is a saving of 100,000 USD (1000 mt x 100$) every month on bunkers.
Original research conducted in 2019, stated that investment made to install scrubbers would be recovered after 2 years of use.
Scrubbers have 2 modules: "Open-loop" and "Closed-loop".
An open loop scrubber continuously washes and discards the treated wash water back into the sea, whereas closed loop scrubbers have an extra process tank to clean the water.
Ports Authorities do not allow any open-loop scrubbers to be used in port, however a study conducted in April 2021 by International Council on Clean Transportation (a nonprofit research group), reported that about 80 percent of that wash water ends up close to shore!
Source:
For another interesting read relating to scrubbers, click here - Scrubber and the aftermath In the blog, we consider whether scrubber instalments have made economic sense.