Marine Exhaust Gas Scrubbers – An Environment Friendly Solution!
Some environmental groups have issued statements saying that the benefits of scrubbers as a compliance route to regulatory requirements are overstated. Spokespersons for these groups suggest that nobody has systematically investigated the impact of scrubbers on the marine environment before adopting this technique as a proper solution to meet the regulations. It is their perception that using scrubbers amounts to discharging harmful substances into the ocean instead of to the air.
Everyone agrees that sulphur in the fuels get converted to oxides of sulphur during the combustion process and these oxides when discharged into the air have a profound damaging effect on the human health, affecting our lungs. They also result in acid rains affecting freshwater and vegetation. Use of expensive low sulphur fuels and exhaust gas scrubbers can be a sort of dual solution to overcome this issue. A Well designed exhaust gas scrubber will scrub oxides of sulphur from the exhaust gas completely.
Scrubbing is carried out using the seawater or alkaline freshwater. Alkaline fresh water is obtained by addition of alkali, such as NaOH to the freshwater.
In the process the oxides of sulphur get converted to Sodium Sulphate which can be discharged into seawater, where the sea water already contains large quantities of Sodium Sulphate. In addition, the scrubbers also remove particulate matters. This particulate matter thus removed can be filtered, dried and used in making bricks.
Further in a good design of scrubber, the pH value of scrubbed water discharged overboard is controlled, so as not to harm the marine life and not to damage the protective coatings on the ship sides.
To say that through the use of scrubbers, the pollution has shifted from air to sea is absolutely baseless and those making such statements have not been properly informed of or have understood the operation of scrubbers.