This paper describes the development and test of a method capable of determining the lubricity of low boiling point fuels with emphasis on Dimethyl Ether (DME).
DME has excellent combustion characteristics but diesel engine injection equipment can break down due to extensive wear when handling this fuel.
Earlier work has established that the lubricity of neat DME is considerably lower than that of diesel oil and kerosene. The repeatability of the results in this former work was poor though.
In the present work, the Medium Frequency Pressurised Reciprocating Rig 2 (MFPRR2) was developed and tested. In this apparatus the influence of the frictional force on the load magnitude was eliminated resulting in a drastic improvement of the repeatability. The lubricity of DME was attempted redressed by adding either commercial wear reducing agents or a high lubricity fuel.
A very few ppm of additive raised the lubricity of DME considerably to a level above the one of kerosene. Only the addition of Lz 539N in proportions above 800 ppm raised the lubricity of DME to a higher level than that of diesel oil. The other investigated additives, regardless of percentage, could not raise the lubricity of DME to the diesel oil level.