The case for instant CO2 reduction in shipping

Fuel is, of course, the primary focus. It represents by far the largest share of emissions on board.
However, once vessels transition to carbon-neutral or carbon-free fuels, system oil and cylinder lubricating oil will represent the vast majority and in practice almost all the remaining fossil oil consumption on board.

This is where an often-overlooked opportunity appears.

Cylinder lubricating oil drained from the engine is traditionally considered total loss oil. It is either burned in low-efficiency devices or disposed of as sludge. Yet this oil still contains valuable hydrocarbons and additives, and oxidation levels are typically minimal.

If this oil can be reused instead of discarded, the impact is immediate:

• Instant reduction in fossil oil consumption
• Significant CO₂ reduction
• Lower operational expenditure
• Improved engine condition and reduced wear on critical components

A simple well-to-wake analysis of cylinder lubricating oil makes the case very clear. From oil well, refinery, transportation, storage, bunkering, and finally disposal, the carbon footprint is substantial. Reducing waste by 50–60% effectively translates into 50–60% less new oil consumption, with a corresponding reduction in CO2 emissions.

Interestingly, early operational experience with fossil-free fuels indicates that their impact on the unburned cylinder oil may be even less severe than with conventional fuels. This makes the drained oil an even better candidate for reuse or repurposing.

At ShipCore, we have developed a simple, efficient, and reliable system that cleans oil drained from engines, scavenge air spaces, and stuffing box drains, making it fully suitable for reuse.

For HFO applications, proper re-additivation through a mixing unit is recommended.
For LSFO operations, re-additivation needs are limited and can be handled through a very simple process.