The Impact of Aliphatic Amines and Tertiary Amides on the Lubrication Properties of Ultra Low Sulfur Diesel Fuels 2000-01-1916

The objective of this work was the assessment of aliphatic amines and tertiary dialkyl-amides as lubrication additives or extenders, on ultra - low sulfur diesel fuels.

In order to evaluate the influence of two types of nitrogen compounds on the lubrication properties of ultra - low sulfur diesel fuels, nine distillation fractions produced by atmospheric distillation of a hydrotreated diesel fuel, were used as the base fuels. Five aliphatic amines and two tertiary amides were used as lubricating additives at five different concentrations i.e. 0.5, 1.0, 2.0, 4.0 and 6.0% by volume, on the nine base fuels. Tribological experiments were carried out on the High frequency Reciprocating test Rig (HFRR). The wear results showed that only four of the five aliphatic amines used, provide satisfactory HFRR mean wear scar diameter (WS 1.4) of less than 460 microns, and at the concentration levels of 1-2% by volume. The concentration levels below 1 % by volume had no effect on the fuel lubricity. Any increase in aliphatic amines concentration, in some cases leads to an insignificant increase of lubricity, while in other cases leads to the decrease of the lubrication effectiveness. In the case of amides, the effective concentration is 1 %, lowering the lubricity value into the acceptable range of less than 460 microns. Again, 0.5 % addition of the additives had no effect on the fuel lubricity, while higher than 2% by volume additive values did not lead to any significant increase in lubricity.