MARPOL Annex VI sets a course for the progressive reduction in the overall sulphur content of fuel used in ships. The global sulphur cap will reduce to from 4.5% to 3.50% effective from 1st January 2012; then progressively to 0.50%, effective from 1 January 2020, subject to a feasibility review to be completed no later than 2018.
The limits on the sulphur content of fuel used in SECAs as defined in the Baltic Sea, North Sea and coast of USA are reduced from 1.5% to 1.0%, from 1st July 2010 and further reduced to 0.10%, effective from 1 January 2015.
The EU has also introduced separate regulations to cut sulphur dioxide emissions from ships and it is placing a limit of 0.1% sulphur in the fuel of ships at berth in all EU ports from 1st January 2010. These changes will mean that vessels will utilise diesel fuels to a greater extent.
Reducing the sulphur content of diesel fuels is known to reduce the inherent lubricity properties of the fuel and history shows that there were many problems encountered in the automotive industry when sulphur content was reduced. The move to lower sulphur content fuels in the marine industry is likely to see a rise in wear problems related to high pressure fuel pumps and injectors that depend on the fuel oil for their lubrication.
Marine Fuel Standard - ISO 8217:2010
The 4th edition of the International Marine Fuel Standard ISO 8217:2010 requires lubricity testing on diesel fuels with sulphur content below 0.05%. In such cases lubricity is specified at max. 520um wear-scar. Equipment manufacturers’ recommendations regarding minimum lubricity requirements must be considered.
Fuel lubricity as a characteristic relates to boundary lubrication properties of a fuel and is distinct from viscosity that is related to the ability of the fuel to generate a hydrodynamic lubricant film. Lubricity is typically measured by a wear scar test.
(EN-590), which measures the wear on a ball-bearing reciprocated at high speed within a High Frequency Reciprocating Rig (HFRR) test rig. The wear scar spec (as lubricity) on automotive diesel fuels is <0.520um of wear.
Nalfleet are pleased to introduce Nalfleet EC5713A - Diesel Fuel Lubricity additive that has been developed to improve the lubricity of low sulphur diesel fuels.
EC5713A has been independently shown to reduce wear scar results in ULSD by up to 45%.
Please contact Jayne Jennings at jjenning@nalco.com or your local Nalfleet sales representative for further information on the availability and application of EC5713A.
www.nalco.com www.nalfleet-nims.com
