ANDRITZ SeaSOx exhaust gas cleaning sysems

ANDRITZ SeaSOx Dual-/Multi-Filtration

ANDRITZ Pulse Jet Fabric Filter (PJFF) technology has been developed as a result of the design and installation of more than 80 fabric filter systems worldwide. ln applications for shipping, this brings many advantages.

Successful installation: Complete retrofit of ANDRITZ SeaSOx Filtration system to La Méridionale´s 40 MW RoRo ferry Piana.

SeaSOx Dual-/Multi-Filtration, single or multi sources scrubbing features:


In the filtration process sodium bicarbonate (NaHCO3) is injected as a dry powder into the existing exhaust pipe. Due to the prevailing high temperature and adequate residence time, the NaHCO3 particle is activated, which increases the reactive surface by many times. This activation is necessary for the NaHCO3 to react with the sulfur components. Such a process requires a temperature of at least 150°C. If the temperature of the exhaust gas stream from the engines is higher than 250°C, a quench is connected upstream, which brings the exhaust gas to the desired temperature by means of evaporative cooling. At the downstream dust filter, on which other particles (e.g. dust, soot ...) are also deposited in addition to the sodium bicarbonate, a filter cake builds up on the filter cloth, and this is where the decisive chemical reaction takes place. SO2 reacts with NaHCO3 to form Na2SO4, which is also present as a powder. After a defined period of time or due to the maximum allowed pressure loss, the dust filter is cleaned by means of a pulse-jet process. During operation, a short stream of air is introduced at high pressure into the bag filter, whereby the filter cake peels off and drops into a collecting funnel. From there, the product is carried off by compressed air and stored in a silo.

ANDRITZ SeaSOxdry process description



  • Low CAPEX (low-cost equipment, little installation work necessary)
  • No dry dock needed
  • SO2 removal to 0.1 or 0.5% S possible
  • Low pressure drop (< 15 mbar)
  • No waste water
  • No plume due to hot process (tail-end SCR possible)
  • No harmful sorbents (NaHCO3 is also known as baking soda)
  • Additional particulate removal > 99 %
  • No pumps, waste water treatment equipment, heat exchangers, filters, or tanks have to be installed in the engine room
  • Multiple inlets possible

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

Exhaust gas emissions from marine diesel engines, mainly containing nitrogen oxides, sulfur oxides, carbon dioxides, and complex particulate matter (PM), are a big concern for human health and the environment. In response to these concerns, the International Maritime Organization (IMO) has introduced regulations for emission control under Annex VI of the MARPOL Convention. Annex VI imposes a framework of mandatory limits on emissions of sulfur oxides (SOx) and nitrogen oxides (NOx), both globally and within designated sea areas known as Emission Control Areas (ECA).

The regulations specify the sulfur content allowed in the fuel to limit the SOx emission. A ship may burn fuel with a higher sulfur content, providing that SOx emissions are controlled to a level that is not higher than the levels emitted when using compliant fuel. In order to comply with the new regulations, ships must either use expensive, low-sulfur fuel or install exhaust gas cleaning units. Based on the operating profile of maritime vessels, exhaust gas cleaning can secure enormous savings in fuel costs and thus provide payback periods of between one and three years. The ANDRITZ SeaSOx technology is the right answer to meet the new requirements and can be installed on all types of maritime vessels, either on a new build or retrofit basis thanks to its flexibility.

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  • SeaSOx Dual/Multi Filtration technology for maritime applications PDF : 524 KB
  • ANDRITZ Scrubbers for the maritime industry PDF : 6.6 MB