Fuel properties and challenges

Conventional heavy fuel oil, with a maximum sulphur content of 3.50%, can only be used on ships that are equipped with exhaust gas scrubbers. Calls in certain ports may require further steps to achieve compliance, including the switch to low-sulphur fuel.

Low-sulphur content HFOs can be used without a scrubber. However, as result of blending different fuels in the production and delivery chain, such fuels may not be tested or evaluated properly. Although, for example, the ISO 8217 standard is in place, there are practical concerns about how to assess fuel compatibility or obtain accurate data describing fuel properties.

Even if delivered as a stable product, blended fuels can become unstable if they mix with other fuels.

Very often especially the fuels with low asphaltene content are subject to stability and compatibility issues, and clogging of asphaltene in the oil, which can cause severe problems and even engine failures on board. Auramarine's PORLA analyser fulfills the need for an easy, reliable and fast analysis instrument to ensure the stability and - when mixing fuels - the fuel compatibility and the recommended mixing order.

MGO may have lower viscosity than the fuels for which the ship s fuel system was originally designed.

Critical fuel supply system parts

• Coolers and in certain circumstances chillers, are needed to reach and maintain the correct MGO viscosity for main and auxiliary engines.
• A fuel pump's ability to accommodate specific fuels should be evaluated. To ensure the correct fuel viscosity, upgrades may be necessary to guarantee pumping capacity and lubricity.
• Fuel transfer and circulation pumps with higher thresholds for leaks or blockages, caused by the varying lubricity of fuels, will also improve long-term cost-efficiency and operational availability.
• Fuel filters should be able to remove cat fines and alert operators about frequent back-flush cycles or clogging.