Evolution of the environmental influences of using exhaust gas cleaning systems (EGCS)
The use of exhaust gas cleaning systems (EGCS), also known as scrubbers, has evolved over time as a means to reduce the environmental impact of ship emissions. Scrubbers work by removing pollutants, such as sulfur oxides (SOx) and particulate matter (PM), from the exhaust gas of ships before it is released into the atmosphere.
Initially, scrubbers were primarily used to comply with regulations limiting SOx emissions in certain areas known as Emission Control Areas (ECAs). These regulations, which were implemented by the International Maritime Organization (IMO), aimed to reduce the environmental and health impacts of SOx emissions, which can lead to acid rain and respiratory issues.
However, as concerns over the environmental impact of shipping have grown, the use of scrubbers has evolved to address a wider range of pollutants. For example, some scrubbers are now designed to also remove nitrogen oxides (NOx) and PM from ship exhaust. This is important as these pollutants also have negative environmental impacts, including contributing to air pollution and climate change.
In addition, the design of scrubbers has also evolved to improve their efficiency and reduce their impact on the environment. For example, many newer scrubbers use closed-loop systems, which involve recycling the scrubbing liquid and reducing the amount of waste produced. Some scrubbers also use advanced technologies such as electrostatic precipitation and catalytic conversion to improve the removal of pollutants.
Despite the benefits of scrubbers in reducing the environmental impact of ship emissions, their use has also been controversial. Critics argue that scrubbers can create other environmental issues, such as discharging pollutants into the ocean and increasing the risk of oil spills. Furthermore, some studies suggest that the use of scrubbers may increase the emissions of certain pollutants, such as PM and NOx, due to the increased sulfur content of the fuel used in scrubber-equipped ships.
To address these concerns, the IMO has proposed new regulations for the use of scrubbers. These regulations include guidelines for the discharge of scrubber washwater and requirements for ships to carry out regular monitoring and reporting of their emissions.
The use of exhaust gas cleaning systems (EGCS) has evolved over time to address a wider range of pollutants and improve the efficiency of scrubbers. However, the use of scrubbers also raises concerns and the IMO has proposed new regulations to address them.

“Emission Control Areas (ECA).” International Maritime Organization, www.imo.org/en/OurWork/Environment/AirPollution/Pages/Emission-Control-Areas-(ECA).aspx.
“How do scrubbers work?” Alfa Laval, www.alfalaval.com/marine/exhaust-gas-cleaning/how-scrubbers-work.
“IMO Proposes New Regulations for Scrubbers.” Marine Insight, 14 Oct. 2019, www.marineinsight.com/news/imo-proposes-new-regulations-for-scrubbers/.
“The Impact of Scrubbers on the Marine Environment.” International Council on Clean Transportation, 22 Jan. 2020, www.theicct.org/publications/impact-scrubbers-marine-environment.