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Reducing marine emissions with continuous gas analyzers

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Four years ago, the International Maritime Organisation (IMO) specified new limits for sulfur dioxide (SO2) and nitrous oxides (NOx) in shipping exhaust gases. The penalties for non-compliance are significant, mandating robust and reliable quality control of incoming petroleum-based fuels.

It is also increasingly important to perform in-line combustion monitoring to quantify the undesirable elements in exhaust fumes against IMO regulations. This is largely conducted using ultra-precise continuous gas analyzers.

The IMO first adopted MARPOL Annex VI in 1997 to prohibit emissions in the maritime industry. They highlighted the importance of preventing air pollution from ships, and taking an increasingly strict perspective on exhaust gas composition:

“Although air pollution from ships does not have the direct cause and effect associated with, for example, an oil spill incident, it causes a cumulative effect that contributes to the overall air quality problems encountered by populations in many areas, and also affects the natural environment, such as tough acid rain.”[1]

Continuous gas analyzers for IMO compliance

Under MARPOL Annex VI, the IMO specified acceptable global limits for SO2 at 3.50%. To ensure compliance with this new, stricter limitation many onboard exhausts utilize a scrubbing system. Scrubbers are used to effectively clean exhaust gases of undesirable particulates and vapors – which is where continuous gas analyzers are most commonly applied.

Scrubbing systems must be monitored continuously to guarantee compliance within the specified limit values of MARPOL Annex VI. A continuous gas analyzer is used to measure the concentration of CO2 and SO2 downstream of the scrubber and transferring data to the primary control system onboard. This facilitates the generation of continuous reports regarding emissions composition, enabling the crew to document and demonstrate compliance with IMO regulations. It can also be used to adjust the performance of the scrubber in real-time.

ABB continuous gas analyzers for emissions control

ABB offers the GAA330-M smart emission monitoring system for marine applications. It can reliably measure the concentration of common pollutants and flue gases like SO2 and carbon dioxide (CO2) using non-dispersive infrared (NDIR) technology. Measurement of NOx is conducted using optional non-dispersive ultraviolet (NDUV) measurements.

It features a standalone cabinet with a modular analyzer and rugged sample probe designs. This robust continuous gas analyzer can accurately monitor multiple measuring points with single- or dual-stream sampling either up- or downstream of the scrubber.

The use of continuous gas analyzers in emissions monitoring and onboard process control is becoming ethically and commercially mandatory, as the IMO has once again changed the limitations on marine emissions. A new global sulfur cap of 0.50% is coming into force in 2020, making process and quality control more critical than ever.

If you would like more information about using ABB continuous gas analyzers for marine emission control, please find your local contact using the form below.



[1] http://www.imo.org/en/ourwork/environment/pollutionprevention/airpollution/pages/air-pollution.aspx


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