ExxonMobil issues guidance for switching to low sulphur fuel
The fuels landscape is set to dramatically change when the International Maritime Organization’s (IMO) 0.5% sulphur cap comes into force on 1 January 2020. Ahead of this, we have come up with some top tips to help the marine industry switch to low sulphur fuels while maintaining a vessel’s safe and reliable operation.
First, establish best practise: Prevention is always better than cure so it is advisable to:
- Buy fuel that meets the latest ISO 8217:2017 specification
- Only bunker from reputable fuel suppliers
- Clean out bunker tank residues when necessary
Test for cat fines: Some new 0.5% sulphur fuels could contain elevated levels of cat fines, which if not properly treated, could trigger catastrophic engine damage. If laboratory testing shows a high concentration then:
- Maintain storage tank temperatures at least 10°C above fuel pour point
- Keep settling tanks at 85°C
- Operate purifiers at optimum efficiency and minimum throughput
- Drain water from fuel tanks to aid settling
Check for compatibility: There is a risk that two compliant fuels will not be compatible, which can trigger damaging sludge formation. It is therefore essential to:
- Test the fuels for compatibility, ideally in a laboratory
- Store fuels separately until testing has been carried out
- If mixing is unavoidable, avoid comingling in excess of 80:20 mix ratio
Monitor for sludge: If sludge does start to form, it is essential to ensure against further fuel blending before any remedial action is taken as this may exacerbate the problem. Then:
- Operate two or more separators in parallel at their lowest throughput
- Increase the frequency of purifier discharge
- Monitor and clean filters frequently
Depending on its features, it may also be possible to use a next generation cylinder condition monitoring service to test a fuel’s sulphur content in order to confirm it meets the revised IMO sulphur cap. Using fuels that do not comply with the emissions regulations could result in costly penalties.