Global maritime insurance provider West of England Protection & Indemnity (P&I) Club (West P&I) recently released an article reminding its members with inert gas systems on their ships to ensure they are maintained in good working to comply with emissions standards and environmental regulations:
Fujairah is a major port in the United Arab Emirates and subject to strict environmental regulations aimed at reducing the impact of shipping on the local environment. Under these regulations, ships must comply with specific emissions standards and may face fines for exceeding them. The emission standards cover various pollutants, including sulphur oxides (SOx), nitrogen oxides (NOx), particulate matter (PM), and volatile organic compounds (VOCs).
The Club regularly receives claims for pollution fines in Fujairah for soot discharge from the ship’s inert gas system. The average fine amount levied for such infringement by the authorities is USD 50,000 per incident.
When a soot discharge from the inert gas system has occurred, the port authorities will be levying the fine because they deem the ship exceeds the PM emissions standard and is further contributing toward the overall air and water pollution that impacts the local ecosystem and wildlife.
The inert gas system on a ship is designed to prevent the build-up of explosive gases in the cargo tanks by reducing the oxygen to a level where an explosion cannot occur. It is achieved by supplying inert gas to the cargo tanks.
Making inert gas on a ship requires fuel oil to be burnt with low excess air in a boiler or dedicated inert gas generator. Subsequently, efficient combustion depends on good atomization/fuel spread when burning fuel with low excess air.
If fuel atomization is poor, then incomplete combustion may result with low excess air levels. As the exhaust gas is washed and cooled in the inert gas scrubber tower, unburnt fuel or soot may enter this water and can be discharged overboard in the scrubber wash water, thus leading to pollution.
If the ship’s inert gas system is discharging soot from the cooling water outlet, it could be an indication of several issues, such as:
Fouled scrubber tower: The build-up of deposits in the scrubber tower can reduce the heat transfer efficiency, leading to higher exhaust gas temperatures and a higher likelihood of soot formation. Regular maintenance and cleaning of the scrubber tower can help prevent this issue.
Improper fuel combustion: The fuel-air mixture in the combustion chamber may not be properly adjusted, leading to incomplete combustion and the formation of soot. This can be addressed by adjusting the combustion parameters and ensuring proper fuel quality.
Insufficient cooling water flow: If the cooling water flow rate is too low, the scrubber tower may be unable to remove enough heat from the exhaust gas, leading to higher exhaust gas temperatures and soot formation. Checking and adjusting the cooling water flow rate can help address this issue.
Overloading of the inert gas system: If the ship’s inert gas system is overloaded, it may be unable to effectively cool the exhaust gas, leading to higher exhaust gas temperatures and soot formation. Properly sizing the inert gas system and avoiding overloading can help prevent this issue.
Consequently, because of the potential outcomes that can arise and to ensure compliance with emissions standards and environmental regulations, we would remind Members with inert gas systems on their ships to ensure that they are maintained in good working order and to take measures to address these issues through proper maintenance and operation to prevent soot formation and ensure safe and efficient operation of the inert gas system.
Photo credit: shraga kopstein on Unsplash
Published: 3 April, 2023
Advanced analytical services will support support clients in the shipping sector allowing for more accurate and efficient testing of methanol as a marine fuel, Bryan Quek tells bunkering publication Manifold Times.
While slow steaming may help save fuel cost and lowers emissions, it may end up being a costly endeavour for ship owners. Innospec suggests looking at smart slow steaming instead, shares Nicea Ng.
Bunker claim was regarding the supply and delivery of RMG380 to the demise charter of the India-flagged oil tanker on 24 February 2022 at Yosu port, according to court documents obtained by Manifold Times.
Claim was regarding sales of LSFO from Gulf Petrochem to Prime Oil Trading on 24 February 2020 which was due for payment on 23 June 2020 after a 120-day credit period, state court documents.
Remi Eriksen of DNV Group, shared during event, the business case for decarbonization must involve four key factors including alternative bunker fuels once safety guidelines and bunkering infrastructure are established.
Malaysian government will ensure all obligations and conditions under the International Convention for the Prevention of Pollution from Ships or MARPOL are implemented, says Transport Minister.