Exam Question
Q6
Compare and contrast open-loop, closed-loop, and hybrid EGCS. What are the advantages and disadvantages of each system, and in what scenarios is each type preferred?
(16)
Class 2 (2nd Engineer)
MEKG
📅 Mar 2026
Reference Answer
### Introduction to Exhaust Gas Cleaning Systems (EGCS)
Exhaust Gas Cleaning Systems, commonly known as scrubbers, are installed on marine vessels to remove Sulphur Oxides (SOx) from the engine exhaust gases. This is a primary method for complying with the stringent limits set by MARPOL Annex VI, Regulation 14, particularly the global 0.50% m/m sulphur cap effective from 1 January 2020 and the 0.10% m/m limit within designated Emission Control Areas (ECAs). EGCS are categorized into three main types: open-loop, closed-loop, and hybrid, each with distinct operating principles, advantages, and disadvantages.
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### 1. Open-Loop EGCS
Exhaust Gas Cleaning Systems, commonly known as scrubbers, are installed on marine vessels to remove Sulphur Oxides (SOx) from the engine exhaust gases. This is a primary method for complying with the stringent limits set by MARPOL Annex VI, Regulation 14, particularly the global 0.50% m/m sulphur cap effective from 1 January 2020 and the 0.10% m/m limit within designated Emission Control Areas (ECAs). EGCS are categorized into three main types: open-loop, closed-loop, and hybrid, each with distinct operating principles, advantages, and disadvantages.
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### 1. Open-Loop EGCS
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