LR Methodology Makes Scrubber Use More Fuel Efficient

LR has worked with Alfa Laval to devise the methodology

Lloyd’s Register (LR) has announced it has developed calculation methodologies for scrubber washwater acidity compliance that allow shipowners to save fuel.

“The calculated methodologies LR is using ensure that the pH emission limit is not relaxed, discharges comply with the intent of the guidelines and pollution shift is prevented,” said LR in this month’s edition of its Horizons publication.

“Ship operators are able to use less energy, save fuel and reduce their carbon footprint.”

International Maritime Organization (IMO) guidelines state that scrubber washwater from “wet scrubber” systems must not exceed a certain level of acidity (pH 6.5), in order to prevent environmental damage.

Shippers are thus required to bring pH levels to 6.5 by diluting washwater and conducting “plume verification” to check the levels before discharging washwater into the sea.

For many shippers this has meant pumping seawater around the ship in a process that consumes fuel, since although “external dilution” is allowed, measuring compliance has hitherto been difficult.

LR says its methodology, developed in conjunction with scrubber manufacturers such as Alfa Laval, offers shipowners a calculation-based way of monitoring external dilution, avoiding the need for fuel-dependent onboard dilution.

LR has approved pH calculations for 26 ships so far, with a further 70 approvals pending.

A number of shipowners have turned to scrubbers for emissions control area compliance, with cruise operator Carnival last year saying it would double its scrubbers installations to cover more than 70 vessels.