A closed-loop scrubber is an exhaust gas cleaning system (EGCS) that controls air pollution on a vessel. In order to comply with the strict IMO 2020 sulfur cap, this method is critical as it reduces sulfur oxides (SOx) emissions from marine exhaust gas streams by as much as 98 %. However, a closed-loop scrubber consists of various elements and complex processes, and let us dive into how a closed-loop scrubber works.
When a ship operates, its engine, auxiliary engine, or boiler generates exhaust caused by combustion processes. Before the shipping industry focused on desulfurization, the exhaust gas went directly into the atmosphere, which caused acid rain, harming people, wildlife, and the planet. Today, the exhaust gas can be cleaned with an exhaust gas cleaning system employing unique scrubber technology. A closed-loop scrubber can remove up to 98 % of sulfur from marine exhaust gases, ensuring a sustainable operation. And more essentially, it ensures compliance with the IMO 2020 sulfur cap by lowering SOx emissions from 3.5 % to less than 0.1 %, allowing ships to operate within the ECA.
There are three types of scrubbers; open-loop, closed-loop, and hybrid. Read more about them and how they differ here.