Formulation and Tribological Behavior of Ultra-low Sulfur Diesel Fuels Microemulsified With Glycerin
The lubricity of diesel is a fundamental parameter, as it has a direct impact on the engine operation, working life and wear of the parts. Ultra-low sulfur diesel fuels (ULSD) have low lubricity due to the removal of polar compounds resulted from the desulfurization process. This study evaluated the impact of glycerin addition on the lubrication properties of ULSD microemulsion fuel. Lubricity tests were developed in High Frequency Reciprocating Rig (HFRR). The results showed that, when compared to the ULSD reference fuel with 10 ppm sulfur, the addition of glycerin at the highest concentration was capable to double the percentage of lubricant film formation, reduce by 48% the wear scar formed in the steel ball and promote the reduction in the values of roughness parameters by approximately 50%.