A closed-loop scrubber is an exhaust gas cleaning system (EGCS) that controls air pollution on a vessel. This method is crucial to comply with the strict IMO 2020 sulfur cap as it reduces sulfur oxides (SOx) emissions from marine exhaust gas streams by 98%.

Closed-loop scrubbers typically utilize alkaline-dosed seawater to scrub the exhaust gas. A closed-loop scrubber only requires half the amount of water to clean the exhaust gas streams compared to the open-loop scrubber. Thereby, the closed-loop scrubber is more energy-efficient.

2021年3月22日 · A closed-loop system requires almost half the volume of wash water than that of the open loop version, however, more tanks are required. These include a process tank or buffer tank, a holding tank through which discharge to sea is prohibited and also a storage tank capable of regulating its temperature between 20º and 50ºC for the sodium ...

Wärtsilä Closed Loop Scrubber operates in a closed loop, i.e. the wash water is being circulated within the scrubber. Only a small bleed-off is extracted from the loop and fresh water and alkali is added. The SOx reduction efficiency is 97,15%, corresponding to a reduction of fuel sulphur content from 3.5% to 0.1%.

2018年10月18日 · Closed-loop scrubbers. Closed-loop systems add chemicals, such as caustic soda, to the wash water to boost its alkalinity. The wash water is then recirculated through the system and partially purged.

2024年7月7日 · Closed Loop Scrubbers. Closed loop scrubbers use a closed system with freshwater mixed with an alkaline substance (usually sodium hydroxide) to neutralize sulphur oxides. Here’s how they work:

2020年2月28日 · These systems offer a simple solution for retrofitting vessels with scrubbers that are capable of operation on both open loop and closed loop configurations. These systems run on open loop mode at sea and closed loop mode in ECA zones and ports and their use can be switched with ease.

2024年11月21日 · Closed-Loop Scrubbers use an alkaline chemical liquid (e.g. sodium carbonate solution) rather than seawater to neutralise sulphur oxides in the exhaust gas. The exhaust gas is sprayed through the alkaline solution to convert the SOx to sulphate.

The closed loop scrubber system works continuously in a closed loop, circulating the wash water within the scrubber. The exhaust gas of the diesel engine enters the scrubber and is sprayed with wash water that has been saturated with an alkali, for example caustic soda (NaOH) or magnesium oxide (MgO).

There are multiple reasons why treating marine exhaust gas streams with a closed-loop scrubber is advantageous, but three significant reasons are worth highlighting.