On-board fuel management: Why it’s more important than ever

ExxonMobil Marine Ship at Port

In light of the imminent 2020 global 0.5% sulphur cap, there will be an increase in the number and variety of fuel options. As a result, fuel-related issues are liable to become more frequent and this will make on-board fuel management more important than ever.

Potential challenges
The new types of fuels and different fuel blends that will enter the market come 2020 may see increased compatibility and stability problems. These issues are critical concerns as they can result in the formation of sludge, which can cause costly and avoidable maintenance. In the worst case scenario, sediment can cause engine fuel starvation and power loss.

On-board fuel testing
Fortunately, on-board testing can provide engineers with an incompatibility warning when mixing or comingling new and existing fuels.

The simple-to-use spot test uses a blend composed of representative volumes of the sample fuels. A drop of the blend is placed on a test paper and heated to 100°C. After one hour, the resultant spot is examined for the presence of solids and rated for compatibility against a reference chart.

It is also possible that some fuels that comply with the 0.5% sulphur cap will have high levels of cat fines, which have the potential to cause significant engine damage, leading to substantial repair costs and potential vessel delays. Operators therefore need to be able to identify if there are issues with the fuel they have bunkered.

It’s important that vessel engineers are aware of the array of available easy-to-perform on-board fuel analyses. In addition to the compatibility spot test it is also possible for the crew to perform simple checks to assess a fuel’s viscosity, water content, density and the presence of cat fines.

However, ExxonMobil recommends that all vessel operators test the bunker fuel at an independent lab to see if it meets its stated specifications given the possibility of contamination in the logistics stream from refinery to the customer. A lab can also carry out highly detailed analysis for issues such as cat fines and stability, which can provide additional peace of mind.

Make sure you use the right cylinder oil
The IMO decision doesn’t just change the fuels landscape; vessel operators will also need to use cylinder oil specifically designed to work with low sulphur fuels in order to ensure the correct level of protection is provided. With the limited number of scrubbers currently in use, many vessels will use 0.5% sulphur fuel for compliance with the global cap and 0.10% sulphur fuels in Emission Control Areas (ECAs). Therefore, the BN level of the cylinder oil will be at the low end of the range and only one cylinder oil will be required on board. Vessels with scrubbers will use only high BN oil and, again, only one cylinder oil will be needed.

It is important that vessel operators work with trusted fuel and lubricant suppliers in order to help ensure that come 2020, they are best positioned to navigate their way around the possible problems.