EGCS Technology

The 3 main types of EGCS are open-loop, closed-loop and hybrid systems.

The technology has significant benefits, including:

  • An EGCS removes sulfur (SOx) from the engine exhaust gas emissions, avoiding the airborne part of the sulfur cycle which causes acid rain.
  • An EGCS also removes a high % of particulate matter (PM) with good effectiveness against the 10 and 2.5 micron size particles and ultrafines, which pose the greatest health hazards.
  • An EGCS allows to burn HFO while easily achieving the IMO MARPOL SOx emission requirements entering into force 1st January 2020, and even better.
  • An EGCS is relatively simple to retrofit and to operate.

The open-loop system uses pure sea water for neutralizing the exhaust emissions. No added chemicals are utilized. The water is taken from sea chest, pumped to the scrubber tower and distributed to the active spray nozzles. Drained washwater is led directly via a sea water overboard discharge line after passing through water analysis sensors to check the regulatory parameter values are within compliance limits.


The closed-loop system uses sea water from a process tank in combination with alkali for neutralizing the effluent process water. Over time the waste concentration by accumulated running hours in closed loop will demand that the process water has to be cleaned. The cleaning is performed via the Water Treatment Unit where the residues are collected in different filtering steps and finally ending up as a concentrated sludge or solid component. The sludge needs to be disposed of ashore.


Capable of running in open-loop or closed-loop mode.