Lubricity Additives and Wear with DME in Diesel Injection Pumps

In recent years it has been demonstrated that Dimethyl Ether (DME) possess many characteristics that could make it a successful alternative to diesel in the next century. High wear of the fuel injection system has been reported. This is caused by lack of natural protective constituents of Dimethyl Ether as well as its low viscosity compared with conventional fuels.

A test rig consisting of conventional fuel injection equipment was developed in order to test the wear-reducing effects of different boundary additives added to a 99.9 % pure Dimethyl Ether fuel base stock. Attempts to characterize wear of standard diesel jerk pump plungers elements were made with weight measurements, diameter measurements, 2-D and 3-D surface roughness measurements, and photography by a Michelson interferometer.

Several lubricity additives were tested, but none reduced wear levels to those for diesel fuel