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  • Scrubbers for the maritime industry - ANDRITZ SeaSOx
  • Exhaust gas cleaning - SeaSOx wet technology

ANDRITZ SeaSOx wet technology

Wet desulphurization process

ANDRITZ SeaSOxwet - I-Type wet (In-line) scrubber, single or multi sources scrubbing features


ANDRITZ SeaSOxwet - U-Type wet (Bypass) scrubber, single or multi sources scrubbing features



In open loop mode, seawater is used as a washing medium to clean the exhaust gas. This simple process makes use of the natural alkalinity of the seawater in chemical absorption of the SOx. For this reason, the washing medium is pumped from sea chests to the absorber, where the absorption process takes place by means of spray scrubbing. The treated exhaust gas can then be released to the environment, and the effluent is also discharged. Both the exhaust gas and the effluent have to meet several critical, environmental constraints, which are validated by continuous emission monitoring.


If the natural alkalinity is too low or discharging of effluent is not allowed, SOx scrubbing is performed in closed loop mode. In this mode, the washing medium is recycled, and a neutralizing agent (50% wt. NaOH, Na2CO3) is added in metered doses to obtain a certain absorption capacity. In order to control the absorption temperature and maintain the water balance, an inline heat exchanger is provided on request to cool the washing medium down. Consequently, the effluent has to be cleaned periodically depending on the engine load, the ship’s route, and its fuel specification. For this application, a washing water treatment unit is installed to separate the particles and salts from the washing medium, in accordance with the MARPOL Convention, before it is discharged into the sea. The sludge generated is collected in a separate tank, while the treated washing water is either stored in the holding tank or discharged into the sea, depending on local discharging restrictions.


A combination of open and closed loop operations is called hybrid mode. In hybrid mode, it is possible to switch between these two processes depending on the predominant basic conditions (seawater alkalinity, discharge restrictions, etc.). This option provides high flexibility and enables customers to choose the best process, both economically and technically.



  • Simple and robust design suitable for inline and by-pass installation.
  • Substantial noise reduction: The silencer can be removed if operated in the inline mode.
  • Exhaust gas can pass through safely, even when the absorber pumps are not operating.
  • Highest removal efficiencies with lowest operating costs, combining ANDRITZ proprietary FGDplus technology and optimized spray bank design.
  • Multiple inlets possible.
  • Smallest footprint due to rectangular design.

ANDRITZ SeaSOx technology  – exhaust gas cleaning systems for the marine industry

SeaSOx dry technology

ANDRITZ SeaSOx dry- the dry desulphurization technology for exhaust gas cleaning on ships.

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Scrubbers for the maritime industry - ANDRITZ SeaSOx

Clean air is the basis for a healthy life. ANDRITZ has developed the SeaSOx technology, which is the right solution to clean exhaust gas in order to meet the new requirements effective 01.01.2020. The SOx scrubbers for the maritime industry are available in open, closed and hybrid mode and can be installed on all types of ships, either on a new build or retrofit basis, thanks to its flexibility.

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Air pollution control technologies

Clean environment for a better tomorrow. ANDRITZ provides innovative air pollution control technologies, including wet flue gas cleaning, dry flue gas cleaning, DeNOx plants, and combined or multi-stage systems.

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ANDRITZ Exhaust gas cleaning for ships
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  • ANDRITZ Scrubbers for the maritime industry PDF : 6.6 MB