Investigating “De Minimis” Level of Fatty Acid Methyl Esters (FAME) in Distillate Marine Gas Oil 2013-01-2697
According to the existing maritime regulation, the marine diesel equipment will be necessary to operate with low sulfur marine fuels. Low Sulfur Middle Gas Oils (MGOs) often have a viscosity that is lower than that of Heavy Fuel Oil (HFO). The problems in diesel engines are mainly related to high pressure fuel pumps that depend on the fuel oil for their lubrication. A solution to that problem probably will be the addition of Fatty Acid Methyl Esters (FAME) as an additive to the fuel. On the other hand, for the purposes of International Standard ISO 8217:2012 in the case of distillate fuels it is recommended that “de minimis” level of FAME is recommended. “De minimis” level is determined approximately as the 0.1% volume of the fuel.
In this study, Distillate Marine Diesel Oil with good lubricity performance was used blended with FAME fuel, according to national and European Standard (ELOT EN 14214), was used as an additive. The FAME was stored for three months period in a plastic container. Then mixture with concentrations of 0.5%, 1.0%, 2.0%, 3.0%, 4.0% and 5.0% by volume were used.
The obtained results shown that all the mixtures are within the specification limits but the tribological measurements, which were carried out with an applied load of 600 g using the High Frequency Reciprocating Rig (HFRR) with test duration for each test 150 min., revealed an increased wear. This happened because after the storage period the water content of the FAME increased significant.