SOx scrubbing is harmless to the marine environment.
We believe knowledge grows
Exhaust gas scrubber systems (EGCS) has been a common and accepted technology in shore-based industries for more than 60 years, and was adapted for use in the maritime industry more than a decade ago. Since then, thousands of scrubbers have been installed worldwide, and ship-owners and operators have learned that there are several benefits to installing a scrubber system.
Lower CO2 footprint
In a study published June 2019 by Norwegian Research Organization SINTEF, Chief Scientist Dr. Elizabeth Lindstad concluded that the continued use of heavy fuel oil (HFO) with a scrubber emits less greenhouse gas emissions compared to marine gas oil (MGO) and LNG-fuel. This is due to the energy consumption during the refining and desulphurisation process.
Installing a SOx scrubber also saves operational costs, as you can continue to use HFO after the 2020 regulations take effect, instead of switching to more expensive compliant fuels.
Several scientific studies conducted over the past ten years show that the washwater discharged from open-loop scrubbers is harmless to local waters and ports. Sea water has a natural alkalinity with capacity to absorb and neutralize the sulphur dioxide gas from the exhaust gas, which is further oxidised to non-toxic sulphate (SO42-) in the ocean. Sulphate is the third most prevalent constituent of sea water after chloride and sodium ions. Studies conclude that discharged washwater from scrubbers has minimal impact on the marine environment and aquatic life, while sulphur in the air harms the human population, erodes buildings and destroys natural habitats through acid rain.
Emissions of particulate matter (PM) from combustion of fuel oils can cause severe health effects. It is estimated that approximately 3% of deaths from cardiopulmonary disease and 5% from lung cancer are attributable to PM emissions globally.
The particle size influences how hazardous the PM emissions are for human health. The World Health Organization has set the limit of PM exposure of fine particles (PM2.5) to be half of the exposure limit of larger particles (PM10), indicating that the toxicity of particulate matter increases with decreasing particle size. Combustion of compliant fuels containing refined products emits more of the finer particles as compared to HFO.
When operating on HFO with a scrubber, close to 75% by mass of the PM emissions from combustion is captured by the scrubber. The number of particles emitted by ships sailing on MGO is more than 2 times higher than from ships operating on HFO with a scrubber.